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Sample records for removable partial denture

  1. Removable partial dentures without rests.

    PubMed

    Meinig, D A

    1994-04-01

    Ever since Bonwill recommended the use of rests on removable partial dentures in 1899, rests have been universally considered inviolate and have gone unchallenged and untested. The author claims that removable partial dentures without rests may not cause the adverse conditions usually predicted, such as gingival stripping, gingival inflammation, mutilated residual ridges, or extensive and rapid resorption of the alveolar ridges. In removable partial dentures made by the author for several patients, the residual ridge remained stable and in physiologic equilibrium when rests were not used. A history of the long-term effect on patients wearing partial dentures with and without rests is presented.

  2. Unilateral removable partial dentures.

    PubMed

    Goodall, W A; Greer, A C; Martin, N

    2017-01-27

    Removable partial dentures (RPDs) are widely used to replace missing teeth in order to restore both function and aesthetics for the partially dentate patient. Conventional RPD design is frequently bilateral and consists of a major connector that bridges both sides of the arch. Some patients cannot and will not tolerate such an extensive appliance. For these patients, bridgework may not be a predictable option and it is not always possible to provide implant-retained restorations. This article presents unilateral RPDs as a potential treatment modality for such patients and explores indications and contraindications for their use, including factors relating to patient history, clinical presentation and patient wishes. Through case examples, design, material and fabrication considerations will be discussed. While their use is not widespread, there are a number of patients who benefit from the provision of unilateral RPDs. They are a useful treatment to have in the clinician's armamentarium, but a highly-skilled dental team and a specific patient presentation is required in order for them to be a reasonable and predictable prosthetic option.

  3. Designing successful removable partial dentures.

    PubMed

    Daher, Tony; Hall, Dan; Goodacre, Charles J

    2006-03-01

    In today's busy dental offices, removable partial denture design is often abdicated by dentists, both as a result of a lack of experience and consensus of design and because of educational failure on the part of dental schools. The result is delegation of the clinical design process to the lab technician. The lack of clinical data provided to the dental technician jeopardizes the quality of care. This article will focus on a logical and simple approach to this problem, making removable partial denture design simple and predictably achievable. The clinical evidence related to removable partial denture design will be described, along with a checklist to simplify the process and make it practical and applicable to everyday clinical practice.

  4. [Indications for removable partial dentures].

    PubMed

    van Waas, M A J

    2009-11-01

    Since there are many ways of preserving a natural dentition, if necessary with support of solitary crowns and fixed partial dentures, sometimes on dental implants, removable partial dentures are nowadays primarily indicated in patients with complaints about missing teeth in the aesthetic zone, which cannot be solved in another way. In addition to this, a removable partial denture is indicated in patients with extremely reduced dentitions or large or multiple edentulous areas, in patients with severe periodontitis or excessive loss of alveolar bone, in patients who are physically or emotionally vulnerable, as an interim solution on the way to edentulousness, as a temporary solution waiting for more extensive treatment and for patients who cannot afford an alternative.

  5. Removable partial denture occlusion.

    PubMed

    Ivanhoe, John R; Plummer, Kevin D

    2004-07-01

    No single occlusal morphology, scheme, or material will successfully treat all patients. Many patients have been treated, both successfully and unsuccessfully, using widely varying theories of occlusion, choices of posterior tooth form, and restorative materials. Therefore, experience has demonstrated that there is no one righ r way to restore the occlusion of all patients. Partially edentulous patients have many and varied needs. Clinicians must understand the healthy physiologic gnathostomatic system and properly diagnose what is or may become pathologic. Henderson [3] stated that the occlusion of the successfully treated patient allows the masticating mechanism to carry out its physiologic functions while the temporomandibular joints, the neuromuscular mechanism, the teeth and their supporting structures remain in a good state of health. Skills in diagnosis and treatment planning are of utmost importance in treating these patients, for whom the clinician's goals are not only an esthetic and functional restoration but also a lasting harmonious state. Perhaps this was best state by DeVan [55] more than 60 years ago in his often-quoted objective. "The patient's fundamental need is the continued meticulous restoration of what is missing, since what is lost is in a sense irretrievably lost." Because it is clear that there is no one method, no one occlusal scheme, or one material that guarantees success for all patients, recommendations for consideration when establishing or reestablishing occlusal schemes have been presented. These recommendations must be used in conjunction with other diagnostic and technical skills.

  6. Evolution of removable partial denture design.

    PubMed

    Becker, C M; Kaiser, D A; Goldfogel, M H

    1994-09-01

    This is a brief overview of the progress of design philosophies of removable partial dentures. It begins in 1711 with the first published description of a removable partial denture prosthesis and continues, with discussion of the most significant discoveries, through 1990.

  7. Removable partial dentures: use of rapid prototyping.

    PubMed

    Lima, Julia Magalhaes Costa; Anami, Lilian Costa; Araujo, Rodrigo Maximo; Pavanelli, Carlos A

    2014-10-01

    The CAD/CAM technology associated with rapid prototyping (RP) is already widely used in the fabrication of all-ceramic fixed prostheses and in the biomedical area; however, the use of this technology for the manufacture of metal frames for removable dentures is new. This work reports the results of a literature review conducted on the use of CAD/CAM and RP in the manufacture of removable partial dentures. © 2014 by the American College of Prosthodontists.

  8. Rotational path removable partial denture design.

    PubMed

    Jacobson, T E; Krol, A J

    1982-10-01

    A detailed description of a rotational path of insertion design for removable partial dentures has been presented. By minimizing the use of conventional clasps, this technique offers some advantages. Rotational path designs may minimize adverse periodontal response to a removable partial denture by reducing plaque accumulation and may be applied in esthetically demanding situations. The design concept involves the use of rigid retentive components that gain access to undercut areas through a rotational path of insertion. These rigid components satisfy the basic requirements of conventional direct retained design.

  9. Flexible thermoplastic denture base materials for aesthetical removable partial denture framework.

    PubMed

    Singh, Kunwarjeet; Aeran, Himanshu; Kumar, Narender; Gupta, Nidhi

    2013-10-01

    Conventional fixed partial dentures, implant supported Fixed Partial Dentures (FDPs) and removable partial dentures are the most common treatment modalities for the aesthetic and functional rehabilitation of partially edentulous patients. Although implants and FDP have certain advantages over removable partial dentures, in some cases, removable partial dentures may be the only choice which is available. Removable cast partial dentures are used as definitive removable prostheses when indicated, but location of clasps may affect aesthetics. So, when patient is concerned about aesthetics, flexible partial dentures which is aesthetically superior to flipper and cast partial dentures, may be considered. But for the success of flexible removable partial denture, proper diagnosis, treatment planning and insertion technique of this prosthesis is very important, which have been thoroughly described in this article.

  10. The oral status of elderly removable partial denture wearers.

    PubMed

    Drake, C W; Beck, J D

    1993-01-01

    A random sample of 1019 elderly home dwelling persons participated in this study. There were 809 dentate respondents, 28.6% of whom wore removable partial dentures. They were examined for coronal and root caries, gingival recession, pocket depth and loss of gingival attachment. The removable partial dentures were also evaluated. Abutment teeth were found to be more likely to have caries and periodontal disease than all other teeth. Using a MANOVA statistical procedure, the analysis indicated that the partial denture itself, irrespective of any professionally determined problems with the denture, appears to affect coronal and root caries on the teeth of partial denture wearers. Partial dentures judged to need repair or adjustment were related to periodontal status. The data on adverse effects of partial dentures suggest a need for patient education by the dentist and through public health measures, and good oral self care and regular professional recall for people who wear removable partial dentures.

  11. Esthetic designs of removable partial dentures.

    PubMed

    Chu, C H; Chow, T W

    2003-01-01

    The increased emphasis on physical appearance in contemporary society has increased the demand for esthetic dental restorations. Although the success of implant dentistry has expanded the scope of esthetic fixed prostheses, many patients demand a removable partial denture (RPD) for health, anatomic, psychological, or financial reasons. Fabricating an esthetically pleasing RPD while avoiding the unsightly display associated with conventional clasp assemblies often presents a challenge to dentists. This article examines using lingual clasps, proximal undercuts (also known as rotational path insertion), and acetal resin clasps as simple and effective means of improving RPD esthetics.

  12. Laser welding of removable partial denture frameworks.

    PubMed

    Brudvik, James S; Lee, Seungbum; Croshaw, Steve N; Reimers, Donald L; Reimers, Dave L

    2008-01-01

    To identify and measure distortions inherent in the casting process of a Class III mandibular cobalt-chromium (Co-Cr) framework to illustrate the problems faced by the laboratory technician and the clinician and to measure the changes that occur during the correction of the fit discrepancy using laser welding. Five identical castings of a Co-Cr alloy partial denture casting were made and measured between 3 widely separated points using the x, y, and z adjustments of a Nikon Measurescope. The same measurements were made after each of the following clinical and laboratory procedures: sprue removal, sectioning of the casting into 3 parts through the posterior meshwork, fitting the segments to the master cast, picking up the segments using resin, and laser welding of the 3 segments. Measurements of all 5 castings showed a cross-arch decrease after sprue removal, an increase after fitting the segments to the master cast, and a slight decrease after resin pickup and laser welding. Within the limitations of this study, the findings suggest that precise tooth-frame relations can be established by resin pickup and laser welding of segments of Co-Cr removable partial denture frameworks.

  13. Turning points in removable partial denture philosophy.

    PubMed

    Waliszewski, Michael P

    2010-10-01

    This article discusses key turning points in removable partial denture (RPD) philosophy. Early advancements tended to focus upon improving the technical quality of the prosthesis itself. The beginning of the 20th century brought significant public pressure upon the dental profession due to consequences associated with poor quality fixed prostheses. The result was dramatic improvement and heavy demand for RPDs. Technical and efficiency issues conspired to temper this enthusiasm, eventually resulting in reduced respect for RPDs. By highlighting key writings and technical issues during these periods of change it is hoped the reader will gain a more precise understanding of the current status of RPD philosophy. © 2010 by The American College of Prosthodontists.

  14. Rotational path removable partial denture: an esthetic alternative.

    PubMed

    Byron, Raymond; Frazer, Robert Q; Herren, Michael C

    2007-01-01

    Missing teeth can be replaced using any of a number of methods. Patients may choose to replace missing teeth with a prosthesis that is either removable, fixed, or retained with implants. When it is necessary to replace anterior or posterior teeth, a properly designed and fabricated rotational path removable partial denture can be both successful and esthetically pleasing to the patient. However, while a patient's functional and esthetic needs can be met successfully, rotational path removable partial dentures can be more demanding for the laboratory technician to fabricate and for the dentist to seat in the mouth. Rotational path removable partial dentures frequently are overlooked as a viable means of treating missing teeth. This article reviews the principles of rotational path removable partial dentures, as well as their categories, advantages, and disadvantages, in the hope that more dentists will consider them when the need arises.

  15. Removable partial dentures with rotational paths of insertion: problem analysis.

    PubMed

    Firtell, D N; Jacobson, T E

    1983-07-01

    Removable partial dentures designed to use a rotational path of insertion are technique sensitive. When indicated and when the principles discussed are followed, a denture that uses a rotational path can be highly successful. Tooth coverage can be decreased, which is an advantage in plaque control, caries reduction, and periodontal support. Esthetics can be improved without resorting to intracoronal retainers, and the number of components subject to distortion is reduced. When properly designed and constructed, use of a rotational path of insertion can result in a removable partial denture that is strong, hygienic, and esthetic.

  16. Removable partial denture with a lateral rotational path of insertion.

    PubMed

    Baharav, H; Ben-Ur, Z; Laufer, B Z; Cardash, H S

    1995-08-01

    A removable partial denture with a lateral path of insertion is useful when unsightly facial clasps are objectional to the patient. Rounded rest seat preparations allow extensions of the minor connector to rotate laterally into embrasure undercuts, providing retention. Guiding planes on the contralateral side ensure a different path of withdrawal from the retentive elements. A Kennedy Class IV arch with a long edentulous span is used to illustrate the denture design.

  17. Holographic stress analysis in a distal extension removable partial denture.

    PubMed

    Campos, José Carlos Reis; Correia, André; Vaz, Mário Augusto Pires; Branco, Fernando Jorge Morais

    2009-09-01

    This study examines stress analysis of the mandible when submitted to mastication simulated forces over a distal extension removable partial denture. Two situations were analyzed upon loading: small pins had been placed over the bone crest and under the denture; low amplitude loads were applied over tooth 34-37. Holographic interferometry techniques were used to assess mandible's deformation. Results indicate that a correct adaptation of the denture base is critical to reduce stresses in the mandible. High stress levels in the second molar region suggest its non-inclusion in these prosthetic rehabilitations.

  18. A clinical overview of removable prostheses: 1. Factors to consider in planning a removable partial denture.

    PubMed

    McCord, J Fraser; Grey, Nick J A; Winstanley, Raymond B; Johnson, Anthony

    2002-10-01

    This is the first article in a series on the prescription of removable partial dentures. It addresses basic clinical and patient-related factors involved in decision-making before commencing active prosthodontic treatment. Further papers will outline a variety of impression techniques for primary and definitive impression, discuss designing principles, give an overview of some technological aspects of removable partial denture-making and provide guidelines on how to diagnose and manage common clinical problems associated with removable partial dentures.

  19. Duplicate casts in fabrication of temporary removable partial dentures.

    PubMed

    Nelson, D R; Palik, J F

    1985-03-01

    The use of blocked-out duplicate casts in the fabrication of temporary removable partial dentures has been described. Temporary removable partial dentures produced in this controlled manner fit properly and aid in minimizing intraoral damage. Accuracy of fit is assured because all relief is accomplished by block out on the surveyor during the laboratory phase rather than by random grinding of the prosthesis at insertion. In addition, the original cast is salvaged and can be used as a meaningful reference during the finishing process in the laboratory (Fig. 5).

  20. Removable partial denture education in Portugal following the Bologna Process.

    PubMed

    Figueiral, M H; Fonseca, P; Campos, J C R; Correia, A R; Fernandes, M S; Branco, F J M

    2013-09-01

    The aim of this study was to investigate the current guidelines used for the undergraduate course subject Removable Partial Denture in Portuguese Dental Schools following the Bologna Process. All Dental Schools were sent a questionnaire, divided into the following areas: (I) organization and syllabus; (II) teaching methods; (III) materials and techniques; Answers about organization and syllabus of course subjects showed the most variability; teaching methods were identical regarding principal textbook and live demonstrations of laboratory/clinical procedures; the same techniques and materials are used in all the schools' dental clinics. The majority of Dental Schools present similar guidelines for removable partial dentures.

  1. Design variations of the rotational path removable partial denture.

    PubMed

    Schwartz, R S; Murchison, D G

    1987-09-01

    The rotational path removable partial denture is a convenient design to use when restoring anterior edentulous spaces and can produce excellent esthetic results. In situations that are not ideal for the conventional rotational path, design alterations can be made that will allow the same excellent results to be achieved.

  2. Esthetic removable partial denture design in replacing maxillary anterior teeth.

    PubMed

    Oh, Won-Suk; Basho, Shveta

    2010-01-01

    Prosthodontic rehabilitation of missing maxillary anterior teeth requires special consideration to restore function and esthetics. This case report describes the prosthodontic management of a patient who lost three maxillary incisors due to a motor vehicle accident. A rotational path removable partial denture was constructed, for which a proximal undercut was created by means of a composite buildup to provide the retention for the prosthesis.

  3. Rotational path of insertion for removable partial dentures with an anterior saddle.

    PubMed

    Yip, Kevin H-K; Fang, Daniel T-S; Smales, Roger J; Newsome, Philip R H; Chow, Tak W

    2003-01-01

    The provision of removable partial dentures remains a viable treatment modality for many partially dentate patients. Replacing missing anterior teeth with a removable partial denture using a rotational path of insertion provides improved retention and appearance. The use of a rotational path of insertion also provides additional retention for a removable partial denture restoring combined anterior and posterior bounded saddles. Two case reports demonstrate the use of the rotational path of insertion for partial denture design.

  4. Removable partial dentures--treatment now and for the future.

    PubMed

    Jones, John D; Turkyilmaz, Ilser; Garcia, Lily T

    2010-04-01

    The use of a removable partial denture (RPD) in clinical practice remains a viable treatment modality. Various advancements have improved the quality of a RPD, subsequently improving the quality of life for the individuals that use them. This article describes four removable partial denture treatment modalities that provide valuable treatment for the partially edentulous patient. These modalities include: the implant supported RPD, attachment use in RPDs, rotational path RPDs, and Titanium and CAD/CAM RPDs. Data on future needs for RPDs indicate that while there is a decline in tooth loss in the U.S., the need for RPDs will actually increase as the population increases and ages. With the growth in the geriatric population, which includes a high percentage of partially edentulous patients, the use of RPDs in clinical treatment will continue to be predictable treatment option in clinical dentistry.

  5. Impact of removable partial denture prosthesis on chewing efficiency

    PubMed Central

    BESSADET, Marion; NICOLAS, Emmanuel; SOCHAT, Marine; HENNEQUIN, Martine; VEYRUNE, Jean-Luc

    2013-01-01

    Removable partial denture prostheses are still being used for anatomic, medical and economic reasons. However, the impact on chewing parameters is poorly described. Objectives The objective of this study was to estimate the impact of removable partial denture prosthesis on masticatory parameters. Material and Methods Nineteen removable partial denture prosthesis (RPDP) wearers participated in the study. Among them, 10 subjects were Kennedy Class III partially edentulous and 9 with posterior edentulism (Class I). All presented a complete and full dentate opposing arch. The subjects chewed samples of carrots and peanuts with and without their prosthesis. The granulometry of the expectorated boluses from carrot and peanuts was characterized by median particle size (D50), determined at the natural point of swallowing. Number of chewing cycles (CC), chewing time (CT) and chewing frequency (CF=CC/CT) were video recorded. Results With RPDP, the mean D50 values for carrot and peanuts were lower [Repeated Model Procedures (RMP), F=15, p<0.001] regardless of the type of Kennedy Class. For each food, mean CC, CT and CF values recorded decreased (RMP, F=18, F=9, and F=20 respectively, p<0.01). With or without RPD, the boluses' granulometry values were above the masticatory normative index (MNI) determined as 4,000 µm. Conclusion RPDP rehabilitation improves the ability to reduce the bolus particle size, but does not reestablish fully the masticatory function. Clinical relevance This study encourages the clinical improvement of oral rehabilitation procedure. PMID:24212983

  6. Acrylic strengthened casts for removable partial denture for occlusion equilibration.

    PubMed

    Oh, Won-Suk; Saglik, Berna

    2011-09-01

    A removable partial denture (RPD) remount cast must resist wear or breakage, present a rigid surface, and ensure a solid support for an accurate equilibration of the occlusion for a RPD. This article describes a procedure of processing a thin layer of tooth colored acrylic resin over the dental plaster to present wear- and fracture-resistant incisal/occlusal surfaces without involving a third material.

  7. Fabrication of interim acrylic resin removable partial dentures with clasps.

    PubMed

    Reitz, P V; Weiner, M G

    1978-12-01

    An orderly sequence of steps for construction of an interim acrylic resin partial denture has been presented. The technique allows the dentist to fabricate an effective restoration that has a definite path of insertion and removal that can be placed in the patient's mouth with little time spent on adjustment and correction. This technique may be used with heat- or cold-curing acrylic resin.

  8. Laboratory considerations in rotational path removable partial dentures.

    PubMed

    Ivanhoe, J R

    2000-10-01

    Clinical indications and contraindications have been well covered in the literature for rotational path removable partial dentures (RPDs). However, only minimal coverage has been devoted to problems encountered that may prevent the proper fabrication of these restorations by dental technicians. The purpose of this article is to illustrate 2 problems that dental technicians occasionally encounter that make the fabrication of rotational path RPDs difficult or impossible. Design modifications by the clinician can eliminate 2 problems faced by technicians fabricating rotational path RPDs.

  9. Laboratory procedures for the one-clasp removable partial denture.

    PubMed

    Ring, M

    1989-05-01

    The lateral rotational path of insertion for removable partial dentures in the Kennedy class II category is generally limited to situations where the dentulous side has been restored with fixed restorations that provide a lingual undercut. The rigid lingual plate is first inserted horizontally into the undercut, followed by a lateral rotation to seat the edentulous side. No alterations of properly designed fixed restorations are necessary. This article discusses the technical procedures in detail.

  10. Masticatory and nutritional aspects on fixed and removable partial dentures.

    PubMed

    Liedberg, B; Norlén, P; Owall, B; Stoltze, K

    2004-03-01

    The aim of the present study was to evaluate mastication, food selection and nutritional aspects in two groups of persons restored with fixed (FPD, N=44) and removable (RPD, N=40) partial dentures respectively. The subjects were part of a cohort study of 67-68-year-old men living in Malmö, Sweden. The two groups were very similar regarding social factors and the inclusion criteria were chosen so that the groups were very equal regarding oral factors, apart from the difference in fixed and removable partial dentures. The number of natural teeth, number of replaced teeth and occlusal contacts did not differ significantly between the two groups, nor did the distribution of maxillary and mandibular dentures. A comprehensive examination of several general health factors included a home interview of dietary habits. A clinical examination included a 20-minute oral examination with registration of number of teeth, FPDs, RPDs, and occlusal contacts. It also included masticatory tests: chewing gum colour mixing, chewing gum bolus shaping, and swallowing threshold (number of strokes to the first swallow of an almond). The consumption of hard and soft foods was revealed by the dietary interview as well as the intake of energy and some nutrients. There was a significant difference between the groups regarding the capacity to mix the two-coloured chewing gum, to shape the chewing gum bolus and in the consumption of hard foods. There was no difference in the swallowing threshold and the consumption of soft foods. The intake of energy and nutrients did not differ significantly between the groups. The differences in masticatory capacity found thus seem to have little, if any, effect on the factors of importance for general health. A reasonable explanation for the differences found is that artificial teeth that are well retained, such as FPDs, make more active chewing possible than do removable, and often somewhat loose-fitting partial dentures.

  11. Distal extension mandibular removable partial denture with implant support

    PubMed Central

    Bural, Canan; Buzbas, Begum; Ozatik, Sebnem; Bayraktar, Gulsen; Emes, Yusuf

    2016-01-01

    This case report describes the fabrication of a distal extension removable partial denture (RPD) of a 65-year-old man with implant support. Loss of fibroelasticity of the peripheral tissues and reduced mandibular vestibular sulcular depth due to a previous surgical resection and radiotherapy at the right side were the main clinical factors that created difficulty for denture retention and stability. The fabrication of a mandibular RPD supported by anterior teeth and two bilaterally placed implants in the molar area to convert from Kennedy Class 1 design to Kennedy Class 3 implant-bounded RPD is reported. Retention and stability of the denture were improved with implant support on the distal extension site of the RPD. The common clinical problems about distally extended RPDs are lack of retention and stability due to the movement around the rotational axis. Dental implant placement to the distal edentulous site minimizes the potential dislodgement of the RPD is popular. Implant-supported RPD can be suggested as an advantageous and cost-effective treatment option for the partially edentulous patients. PMID:28042277

  12. Detection of binding areas on removable partial denture frameworks.

    PubMed

    Stendahl, C G; Grob, D J

    1979-01-01

    Owing to a multiplicity of errors introduced during impression procedures and fabrication, disclosure of binding areas on the metal framework is an essential part of any removable partial denture service. Disclosure is best accomplished with an indicator that provides a sensitive, thin, even, and opaque coating. The aims of adjustment or relief are to maintain forces along the long axis of abutment teeth and ensure passivity, and in so doing create a more favorable prognosis. Careful consideration and thought must precede any reduction. Experience should contribute greatly in determining the indicated reduction and the accuracy of performing it.

  13. Epidemiological Data and Survival Rate of Removable Partial Dentures.

    PubMed

    Moreno, Amália; Haddad, Marcela Filié; Goiato, Marcelo Coelho; Rocha, Eduardo Passos; Assunção, Wirley Gonçalves; Filho, Humberto Gennari; Santos, Emerson Gomes Dos; Sonego, Mariana Vilela; Santos, Daniela Micheline Dos

    2016-05-01

    The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate.

  14. Epidemiological Data and Survival Rate of Removable Partial Dentures

    PubMed Central

    Moreno, Amália; Haddad, Marcela Filié; Rocha, Eduardo Passos; Assunção, Wirley Gonçalves; Filho, Humberto Gennari; Santos, Emerson Gomes Dos; Sonego, Mariana Vilela; Santos, Daniela Micheline Dos

    2016-01-01

    Introduction The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. Aim This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. Materials and Methods Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. Results A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. Conclusion The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate. PMID:27437367

  15. Surface treatments to improve bond strength in removable partial dentures.

    PubMed

    Kim-Hai, Nguyen; Esquivel-Upshaw, Josephine; Clark, Arthur E

    2003-01-01

    The metal and resin interface of removable partial dentures is weakened by the poor bond strength between the two materials. This study was designed to test the hypothesis that surface treatments--consisting of air abrasion, with aluminum oxide, tin plating and oxidation, and silanation, either alone or in combination--will improve the bond strength of acrylic resin to metal. Statistical analysis revealed that air abrasion, tin plating/oxidation, and silanation all showed significantly higher bond strength than either abrasion and tin plating, abrasion and silanation, or abrasion alone. Air abrasion demonstrated the greatest effect on improving bond strength. The mean bond strength of samples subjected to a combination of air abrasion, tin plating and oxidation, and silanation was significantly greater than any other combination treatment.

  16. Comparison of disclosing media used for adjustment of removable partial denture frameworks.

    PubMed

    Dukes, B S; Fields, H

    1981-04-01

    An investigation was conducted to evaluate eight disclosing media for the detection of binding or interference regions on removable partial denture frameworks. The aerosol spray media were judged to be the most acceptable of those tested because they are easy to use and afford minimal waste; they also adhere well to removable partial denture metals and while easily removed, they are not washed away by excess saliva.

  17. Button versus buttonless castings for removable partial denture frameworks.

    PubMed

    Mohammed, H; Hassaballa, M A; Talic, Y F

    1994-10-01

    Casting removable partial dentures (RPDs) without completely filling the sprue channels and generating casting buttons would result in saving metal and making more defect-free castings. This investigation tested whether a complete and sound RPD casting can be obtained when a minimal amount of metal is used. A factorial experimental design, three spruing methods, two metal feeding directions, and two different weights of metal were used to cast 60 Kennedy class II, modification 1 RPDs. The metal used to cast each framework was either enough to result in a full button or in no button. Visual and radiographic examinations and counting of defects were made by two independent operators who were unaware of the spruing method, feeding direction, or amount of metal used to make the framework. The completeness of the casting and the presence of porosities were evaluated for clasps, major connectors, and meshworks. The use of minimal metal to cast RPDs was equally as successful as using enough for a full button, provided that the appropriate spruing arrangement and metal feeding direction were chosen. Indirect metal feeding for maxillary RPDs was successful with the proper spruing arrangement.

  18. Occlusion and Temporomandibular Function among Subjects with Mandibular Distal Extension Removable Partial Dentures

    PubMed Central

    Creugers, N. H. J.; Witter, D. J.; Van 't Spijker, A.; Gerritsen, A. E.; Kreulen, C. M.

    2010-01-01

    Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n = 25) were compared with subjects with shortened dental arches without extension (n = 74) and with subjects who had worn a mandibular extension removable partial denture in the past (n = 19). Subjects with complete dentitions (n = 72) were controls. Data were collected at baseline and at 3-, 6-, and 9-year observations. Results. Occlusal activity in terms of reported awareness of bruxism and occlusal tooth wear of lower anterior teeth did not differ significantly between the groups. In contrast, occlusal tooth wear of premolars in shortened dental arches with or without extension dentures was significantly higher than in the controls. Differences amongst groups with respect to signs and symptoms related to temporomandibular disorders were not found. Occlusal support of the dentures did not influence anterior spatial relationship. Occlusal contacts of the denture teeth decreased from 70% for second premolars via 50% for first molars, to 30% for second molars. Conclusions. Mandibular distal extension removable partial dentures in moderate shortened dental arches had no effects on occlusion and temporomandibular function. PMID:20671961

  19. Removable partial denture alloys processed by laser-sintering technique.

    PubMed

    Alageel, Omar; Abdallah, Mohamed-Nur; Alsheghri, Ammar; Song, Jun; Caron, Eric; Tamimi, Faleh

    2017-05-31

    Removable partial dentures (RPDs) are traditionally made using a casting technique. New additive manufacturing processes based on laser sintering has been developed for quick fabrication of RPDs metal frameworks at low cost. The objective of this study was to characterize the mechanical, physical, and biocompatibility properties of RPD cobalt-chromium (Co-Cr) alloys produced by two laser-sintering systems and compare them to those prepared using traditional casting methods. The laser-sintered Co-Cr alloys were processed by the selective laser-sintering method (SLS) and the direct metal laser-sintering (DMLS) method using the Phenix system (L-1) and EOS system (L-2), respectively. L-1 and L-2 techniques were 8 and 3.5 times more precise than the casting (CC) technique (p < 0.05). Co-Cr alloys processed by L-1 and L-2 showed higher (p < 0.05) hardness (14-19%), yield strength (10-13%), and fatigue resistance (71-72%) compared to CC alloys. This was probably due to their smaller grain size and higher microstructural homogeneity. All Co-Cr alloys exhibited low porosity (2.1-3.3%); however, pore distribution was more homogenous in L-1 and L-2 alloys when compared to CC alloys. Both laser-sintered and cast alloys were biocompatible. In conclusion, laser-sintered alloys are more precise and present better mechanical and fatigue properties than cast alloys for RPDs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  20. Removable Partial Denture Supported by Implants with Prefabricated Telescopic Abutments - A Case Report

    PubMed Central

    Sehgal, Komal

    2014-01-01

    Implants have been designed to rehabilitate edentulous patients with fixed prosthesis or implant supported overdentures. Implant-supported single crowns and fixed partial dentures have become successful treatment alternatives to removable and fixed partial dentures. However, it is common to have clinical situations which make it impossible to use conventional as well as implant supported fixed partial dentures. The implant supported removable partial dentures can be a treatment modality that offers the multitude of benefits of implant-based therapy—biologic, biomechanical, social, and psychological to such patients. The aim of this article is to present a case report describing the fabrication and advantages of removable partial denture supported by teeth and implants for a patient with long edentulous span. The patient was satisfied with his dentures in terms of function and aesthetics. Regular follow-up visits over a period of three years revealed that the periodontal condition of remaining natural dentition and peri-implant conditions were stable. There was no evidence of excessive residual ridge resorption or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. PMID:25121066

  1. [Influence of the supporting mechanism of removable partial denture on the stomatognathic system].

    PubMed

    Tsuchiya, Kyoko

    2010-03-01

    The connecting rigidity of the retainer and the denture supporting area may influence the distribution of the occlusal load. Three types of retainers (wrought wire clasp, Akers cast clasp and conical crown telescopic retainer) and three outline forms of denture bases designed for distal extension removable partial dentures were assessed in six patients with Kennedy Class II situations. To evaluate the influence of oral function, mandibular displacement, abutment tooth displacement, and denture base exerted pressure were measured simultaneously during maximum voluntary clenching. The mandibular displacement increased when the connecting rigidity decreased or the size of the denture base was reduced. The abutment tooth displacement increased as the denture base was reduced with the Akers clasp. The denture base pressure increased as the denture base reduced with the wrought wire clasp. The conical crown telescopic retainer did not cause overloading to the supporting tissues even when the denture base was reduced. It was also revealed that the abutment tooth tended to displace distally when a distal occlusal rest was prepared on the abutment tooth.

  2. Attachment of swing-lock labial bar to an existing removable partial denture: a clinical report.

    PubMed

    Stevenson, R B; Wilson, W G; Caponigro, C V

    1988-10-01

    Although the swing-lock buccal or labial bar is often used as a periodontal splint for mobile teeth, it may also function as an orthodontic retainer to inhibit tooth migration of poorly aligned teeth. The labial bar may be added to an existing removable partial denture if there is sufficient bulk of acrylic resin in the denture bases to accommodate the hinge and latch.

  3. Factors related to patients' general satisfaction with removable partial dentures: a stepwise multiple regression analysis.

    PubMed

    Zlatarić, Dubravka Knezović; Celebić, Asja

    2008-01-01

    This study aimed to analyze factors related to patients' general satisfaction with removable partial dentures (RPDs), such as esthetics, retention, speech, chewing, and comfort. A total of 103 patients with Kennedy Class I RPDs (34 to 82 years old; mean age: 63; 35 men, 68 women) assessed their satisfaction with dentures. Stepwise multiple regression analysis was used to evaluate the relationship among the factors. Significant correlations were found between general satisfaction and each of the individual components (P < .05). The patients' assessment of esthetics explained almost 50% of general satisfaction in both arches (P < .05). Esthetics, chewing, and speech had significant effects on the patients' general satisfaction with dentures.

  4. Full mouth rehabilitation of destroyed dentition with rotational path removable partial denture: a case report.

    PubMed

    Kim, Moon-Hyoung; Heo, Seong-Joo; Kim, Seong-Kyun; Koak, Jai-Young

    2010-06-01

    Though implant dentistry is very successful and predictable in treatment of patients with destroyed dentition, there are some cases with limitations to implant therapy. In these cases, alternative treatment modality should be considered. A patient with destroyed dentition was rehabilitated with a lateral rotational path removable partial denture. According to the diagnosis, we determined to raise vertical dimension for esthetic and functional restoration. The final restoration was performed after four months of provisional period. The edentulous patients with compromised esthetics and functions can be successfully treated with a rotational path removable partial denture through adequate treatment planning and precise laboratory procedure.

  5. Full mouth rehabilitation of destroyed dentition with rotational path removable partial denture: a case report

    PubMed Central

    Kim, Moon-Hyoung; Heo, Seong-Joo; Kim, Seong-Kyun

    2010-01-01

    BACKGROUND Though implant dentistry is very successful and predictable in treatment of patients with destroyed dentition, there are some cases with limitations to implant therapy. In these cases, alternative treatment modality should be considered. CASE DESCRIPTION A patient with destroyed dentition was rehabilitated with a lateral rotational path removable partial denture. According to the diagnosis, we determined to raise vertical dimension for esthetic and functional restoration. The final restoration was performed after four months of provisional period. CLINICAL IMPLICATION The edentulous patients with compromised esthetics and functions can be successfully treated with a rotational path removable partial denture through adequate treatment planning and precise laboratory procedure. PMID:21165187

  6. Clinical Evaluation of Removable Partial Dentures on the Periodontal Health of Abutment Teeth: A Retrospective Study

    PubMed Central

    Dula, Linda J; Ahmedi, Enis F; Lila-Krasniqi, Zana D; Shala, Kujtim Sh

    2015-01-01

    The aim of this retrospective study was to evaluate the effect of removable partial dentures in periodontal abutment teeth in relation to the type of denture support and design of RPD in a five-year worn period. Methods : A total of 64 patients with removable partial dentures (RPDs), participated in this study. It were examined ninety-one RPDs. There were seventy-five RPDs with clasp-retained and sixteenth were RPDs with attachments. There were 28 females and 36 males, aged between 40-64 years, 41 maxillary and 50 mandible RPDs. For each subjects the following data were collected: denture design, denture support, and Kennedy classification. Abutment teeth were assessed for plaque index (PI), calculus index (CI), blending on probing (BOP), probing depth (PD), gingival recession (GR), tooth mobility (TM). Level of significance was set at p<0.05. Results : According to denture support of RPD, BOP, PD, PI, GR, CI and TM-index showed no statistically significant difference. Based on the denture design of RPD’s, BOP, PD, PI, CI, and TM-index proved no statistically significant difference. Except GR-index according to denture design confirmed statistically significant difference in RPD with clasp p<0.01. The higher values of all periodontal parameter as BOP, PD, PI, CI and TM were in patients with RPD’s with claps comparing with RPD’s with attachment. Conclusion : RPD’s with clasp increased level of gingival inflammation in regions covered by the dentures and below the clasp arms in abutment teeth. PMID:25926896

  7. Effect of direct relining on stresses at the denture base and the metal frame of removable partial dentures.

    PubMed

    Al-Ghannam, N A; Fahmi, F M

    2005-02-15

    The Kennedy Class I removable partial denture (RPD) can cause stress to supporting hard and soft tissues and may lead to harmful effects. The purpose of this study is to investigate the pattern of these stresses in three different positions before and following a relining procedure. Ten patients, five males and five females, with a lower distal extension RPD and an opposing upper class III type RPD were selected for this study. Strain gauges together with a strain gauge indicator were used to study the pattern of stresses in three selected positions. Some changes were significantly different at the site of the denture base and at the metal frame near the direct retainer. After relining, the stresses were shared partially by the abutments and partially by the tissues. Maximum stresses were reported during swallowing. No significant difference was noticed between males and females.

  8. Unilateral rotational path removable partial dentures for tilted mandibular molars: design and clinical applications.

    PubMed

    Luk, K; Tsai, T; Hsu, S; Wang, F L

    1997-07-01

    This article describes the design of a unilateral rotational path removable partial denture to restore a single edentulous space with a tilted mandibular molar. It is modified from an original bilateral rotational path design and consists of several components, which are (1) the rotation axis, (2) the long occlusal rest, (3) the short bracing arms, (4) the rigid retainer and extended proximal plates, (5) the conventional direct retainer assembly, and (6) optional auxiliary rest. The stability and retention of the denture are controlled anteriorly by the buccal retentive clasp and lingual guide plate of the conventional direct retainer, and posteriorly by the rigid retainer and its buccally and lingually extended proximal plates. The clinical results of the dentures used in strictly selected situations are excellent; however, it is emphasized that a unilateral denture is only an alternative rather than a routine application. The risk of accidental aspiration is also of concern.

  9. Oral rehabilitation of a patient with congenital partial anodontia using a rotational path removable partial denture: report of a case.

    PubMed

    Reagan, S E; Dao, T M

    1995-03-01

    This case report describes the treatment of an adult patient with partial anodontia. Treatment began with the extraction of several retained primary teeth and the insertion of an immediate transitional removable partial denture that was used to evaluate the possibility of increasing the patient's vertical dimension of occlusion. Later, the entire mandibular arch was restored with fixed restorations. Once the vertical dimension of occlusion was established and controlled, the maxillary arch was restored. Metal-ceramic crowns placed on the central incisors were contoured to accommodate a rotational path removable partial denture. The partial denture utilized rigid metal retention on the distal surface of the central incisors instead of clasps. This design produced a very esthetic and stable prosthesis.

  10. Telescopically retained removable partial dentures on CAD/CAM generated all-ceramic primary telescopes.

    PubMed

    Bär, C; Reich, S

    2008-01-01

    The provision of patients with removable partial dentures on all-ceramic primary crowns with electroplated gold secondary parts is described as an alternative worthy of consideration in dental journals, lectures and in further training courses. The mode of operation is based on a precise, frictionless, passive fit between female and male components. To guarantee this even over large spans, intraoral joining of the individual components is necessary. However, this requires a different sequence of the treatment steps. The different procedures (conventional, procedure by Weigl, modified concept) are described in the following article. Clinical considerations, design principles, and special characteristics involved in producing the partial denture are explained.

  11. Posterior open occlusion management by registration of overlay removable partial denture: A clinical report

    PubMed Central

    Nosouhian, Saeid; Davoudi, Amin; Derhami, Mohammad

    2015-01-01

    This clinical report describes prosthetic rehabilitation of posterior open bite relationship in a patient with several missing teeth and skeletal Class III malocclusion. Primary diagnostic esthetic evaluations were performed by mounting casts in centric relation and estimating lost vertical dimension of occlusion. Exclusive treatments were designated by applying overlay removable partial denture with external attachment systems for higher retentions. PMID:26929544

  12. A maxillary laser-welded component removable partial denture: a clinical report.

    PubMed

    Domagala, Daniel M; Waliszewski, Michael P

    2009-01-01

    Component removable partial dentures (RPDs) are fabricated in pieces and assembled on the definitive cast. The treatment modality described is believed by the authors to optimize the passive fit and frictional retention of the RPD. Increased frictional retention and stability is believed to improve the clinical performance of the RPD. Patients may thereby benefit from more esthetic and more durable prostheses.

  13. Aesthetic considerations for the treatment of partially edentulous patients with removable dentures.

    PubMed

    Budtz-Jørgensen, E; Bochet, G; Grundman, M; Borgis, S

    2000-10-01

    Treatment with removable partial dentures (RPDs) is an affordable solution for anterior or posterior tooth loss. In determining a proper treatment solution, it is important for the clinician to consider the patient's aesthetic expectations, socioeconomic situation, and the prognosis for the prosthesis and remaining dentition. This article presents guidelines to optimize the aesthetic result of this treatment and considers framework and clasp concepts; rotational path design; minimal extension of the denture bases; auxiliary attachments or retentive bars; and implants for retention and support of RPDs.

  14. Mandibular implant-supported removable partial denture with distal extension: a systematic review.

    PubMed

    de Freitas, R F C P; de Carvalho Dias, K; da Fonte Porto Carreiro, A; Barbosa, G A S; Ferreira, M A F

    2012-10-01

    The aim of this article is to investigate patient satisfaction, survival rate of implants, and prosthetic complications or maintenance for rehabilitation with removable partial dentures associated with implants in mandibular Kennedy class I and II cases. A systematic literature review was conducted by three independent reviewers including articles published from January 1981 through September 2011. Medline and Cochrane Library electronic databases were used in addition to hand searching to assess clinical outcomes for mandibular implant-supported removable partial denture with distal extension. This review yielded 1751 records that were narrowed down to 5. The studies revealed implant survival rates ranging from 95% to 100% with one failure reported of 98 implants. The removable partial dentures associated with implant in mandibular free-end arches showed some complications and need of repair for relining, pitting of the healing abutment, replacement of resilient component of the attachment, damage in framework, screw loosening and damage in acrylic denture base. Patient satisfaction was evaluated through a five-point questionnaire, and results ranged between 4.12 and 5.0, considering 1 as the least favourable situation. The literature review showed increase in patient satisfaction and high survival rates of implants associated with mandibular removable partial dentures with distal extensions. However, some complications and need of prosthetic repair were reported. Although this treatment approach could represent a low-cost and beneficial rehabilitation for free-end mandibular ridges, the lack of controlled and randomised well-designed clinical trials suggests further studies with more representative samples to validate the outcomes of this treatment modality. © 2012 Blackwell Publishing Ltd.

  15. Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

    PubMed Central

    Pommer, Bernhard; Krainhöfner, Martin; Watzek, Georg; Tepper, Gabor; Dintsios, Charalabos-Markos

    2012-01-01

    The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture. PMID:23193407

  16. A new device for blockout procedures in rotational path removable partial dentures.

    PubMed

    Luk, K C; Chen, P S

    1993-05-01

    The rationale of a rotation axis is discussed and on this basis a blockout device is designed for rotational path removable partial dentures. This device has three basic components, which are (1) the acrylic resin block, (2) the rotation axis, and (3) the functional part. In the blockout procedures for removable partial dentures with tilted mandibular molars, the rotation axis of the prosthesis is first localized by the blockout device. A knife edge, made of Duralay resin that corresponds to the survey lines of teeth to be used as supports, is constructed and is joined to the functional part of the blockout device. Blockout regions are determined by the rotational movement of the Duralay resin knife edge along the rotation axis of the blockout device. In addition to the function of blockout, the device can also be used to analyze diagnostic casts for critical undercuts. Internal and external types of blockout devices are also discussed.

  17. Symposium on semiprecision attachments in removable partial dentures. Occlusal relationships.

    PubMed

    Whitbeck, P; Ivanhoe, J R

    1985-01-01

    This article discusses current concepts of occlusion and describes the methods of creating a physiologic occlusion for the partially edentulous patient. Specific recommendations are made for choices of materials, techniques, and occlusal schemes for various edentulous situations.

  18. Patient’s Satisfaction with Removable Partial Dentures: A Retrospective Case Series

    PubMed Central

    Shala, Kujtim Sh.; Dula, Linda J.; Pustina-Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F.; Lila-Krasniqi, Zana; Tmava-Dragusha, Arlinda

    2016-01-01

    This retrospective clinical study aimed to assess patient’s satisfaction with removable partial dentures (RPDs), as retention, chewing ability, aesthetics during the observation period. Material and Methods: A total of 63 patients with RPDs, participated in this study. The following data was collected: Kennedy classification, denture design, denture support, satisfaction and success of RPD. Result: The results showed that 73.6% of patients were wearing RPD for the first time and were finally satisfied. According to the denture support of RPDs, clasp-retained quadrangular RPDs were 100% effective, followed by triangular dental support 81% and linear dental support 47.7%. Comparison of RPDs with attachment with RPDs with claps assessed through Fisher exact test, confirmed statistically significant difference (P=0.008), despite retention; however, chewing ability and aesthetics showed no statistically significant difference with X 2 test on patient’s satisfaction with RPD with or without attachment. Conclusion: Patients often would prefer not showing the anterior buccal clasps of RPD, therefore are generally satisfied more with RPD with attachment based on level of retention, chewing ability and aesthetics. PMID:28077970

  19. A preliminary report of designing removable partial denture frameworks using a specifically developed software package.

    PubMed

    Han, Jing; Wang, Yong; Lü, Peijun

    2010-01-01

    This article reports on a method to digitally survey and build virtual patterns for removable partial denture (RPD) frameworks using a new three-dimensional (3D) computer-aided design/computer-assisted manufacturing (CAD/CAM) software package developed specifically for RPD design. The procedure included obtaining 3D data from partially dentate casts, deciding on the path of insertion, and modeling the shape of the components of the frameworks digitally. The completed model data were stored as stereolithography (STL) files, which are commonly used in transferring CAD/CAM models to rapid prototyping technologies. Finally, metal RPD frameworks were fabricated using a selective laser melting technique.

  20. [The use of Dental D (polyacetal resin) as an alternative for chrome-cobalt removable partial denture: a case report].

    PubMed

    Savion, Y; Sharon-Buller, A; Kalisker, Y; Kalisker, N; Sela, M

    2001-10-01

    Polyacetal resin (Delrin) is well known material in many medical fields as for artificial heart valves and artificial hip joints. In dentistry the material is known as Dental D, and among its other applications, is used for removable partial dentures. The article presents a cleft lip and palate patient with missing teeth (12 and 22). The patient underwent on operations for closure of the cleft, but even so some sinus tracts from the nasal cavity to the soft and hard palate exist. The patient was rehabilitated 10 years ago with chrome-cobalt removable partial denture, but lately, episodes of swelling and burning sensation were reported. The patient was diagnosed (by the allergy clinic in Hadassah hospital) as allergic to chrome-cobalt. Some optional treatment plans were offered to the patient (fixed, which involved an operation of closing the fistulas, and then a fixed restoration, another option was removable denture with Dental D). The patient chose to be rehabilitated with Dental D removable partial denture, which closes the fistulas and reconstructs the missing teeth. Due to the physical properties of the Dental D, its biocompatibility and the improved esthetics results, the Dental D can be a good alternative for the chrome-cobalt removable partial denture. The esthetic results with the Dental D, as far better than the conventional partial denture.

  1. [Influence of attachment type on stress distribution of implant-supported removable partial dentures].

    PubMed

    Yang, Xue; Rong, Qi-guo; Yang, Ya-dong

    2015-02-18

    To compare influences of different retention attachments on stress among supporting structures. By 3-dimensional laser scanner and reverse engineering computer aided design (CAD) software, a basic partially edentulous digital model with mandibular premolar and molar missing was established. Implant attachment and removable partial dentures (RPD) were added into the basic model to build three kinds of models: RPD only, RPD + implant + Locator attachment, and RPD + implant + Magfit attachment. Vertical and inclined loads were put on artificial teeth unilaterally. By means of 3-dimensional finite element analysis, the stress distribution and displacement of the main supportive structures were compared. A complete 3-dimensional finite element model was established, which contained tooth structure, and periodontal structures. The displacement of the denture was smaller in Locator (9.38 μm vertically, 45.48 μm obliquely) and Magfit models (9.54 μm vertically, 39.45 μm obliquely) compared with non-implant RPD model (95.27 μm vertically, 155.70 μm obliquely). Compared with the two different attachments, cortical bone stress value was higher in Locator model (Locator model 10.850 MPa vertically, 43.760 MPa obliquely; Magfit model 7.100 MPa vertically, 19.260 MPa obliquely).The stress value of abutment periodontal ligamentin Magfit model (0.420 MPa vertically) was lower than that in Locator model (0.520 MPa vertically). The existence of implant could reduce maximum von Mises value of each supportive structure when Kennedy I partially edentulous mandible was restored. Comparing the structure of Magfit and Locator attachment, the contact of Magfit attachment was rigid, while Locator was resilient. Locator attachment could improve stability of the denture dramatically. Locator had stronger effect on defending horizontal movement of the denture.

  2. In vitro retention loss of attachment-retained removable partial denture.

    PubMed

    Can, Gülsen; Özmumcu, Baransel; Altinci, Pinar

    2013-11-01

    To investigate the importance of attachment types on the retention loss of extracoronal attachment-retained removable partial dentures depending on the usage period. In order to observe the retention loss of 5 different attachments (OT Strategy, OT Strategy-metal protected, Vario-stud-snap and Vario-soft 3 and ERA-RV) over time, attachment-retained partial dentures representing Kennedy II mod. I case were placed in a custom-made, retention test machine. For each minute, eight separating and joining movements were performed and retention values (Newton) of the attachments were recorded by computer. The retention tests implemented in 540,1080 and 2160 cycles. The data were evaluated statistically according to the two-way ANOVA and Tukey parametrical tests. The slide type attachment providing the best retention force was observed to be the most worn out by this process (p < 0.01) while the ball type attachments, which typically have the lesser retention force, showed less retention loss (p < 0.01). It can be concluded that the retention attributes of the attachment-retained dentures were affected by the specific type of precision attachment as well as the usage period. Precision attachments with ball-type plastic matrices may be recommended for the clinical use due to their retention stability over time.

  3. A follow-up study on removable partial dentures in undergraduate program: part I. participants and denture use by telephone survey.

    PubMed

    Yoshida, Eiko; Fueki, Kenji; Igarashi, Yoshimasa

    2011-07-04

    The aim of this study was to investigate the clinical outcome of removable partial dentures (RPDs) designed to minimize denture mobility during function. Using archived files of the undergraduate program between 2003 and 2005 at Tokyo Medical and Dental University, a list of 169 patients treated with 184 RPDs was created. The RPDs had either an acrylic resin-base or a cobalt-chrome framework-base. Two examiners telephoned all the listed patients and interviewed 118 patients (70%) regarding the use of their RPDs. Of 118 patients, 42 (36%) had stopped using, mainly due to problems with abutment teeth in resin-based dentures, and replacement in cobalt-chrome-based dentures. There was no significant difference in mean age, gender distribution, mean number of remaining/abutment teeth, distribution of denture arch, and Kennedy classification between denture use and nonuse groups (p>0.05). The nonuse group showed a significantly higher percentage of resin-base compared to the use group (p = 0.006). Logistic regression analysis indicated that resin-base was a significant risk factor for nonuse (p = 0.008). The present findings suggest that abutment teeth should be selected carefully, especially in this type of resin-based RPDs, and that the denture base material may be a critical factor which determines denture use.

  4. The functional bilaminar impression technique for the distal extension removable partial denture.

    PubMed

    Stillwell, K David; Eshelman, E Grant

    2007-01-01

    In recent years, many clinicians have abandoned the time-consuming and technique-sensitive border-molded custom impression in favor of a simplified stock tray and irreversible hydrocolloid final impression. However, the master cast obtained by this simplified method often will lead to a completed prosthesis that has inadequate support from the distal extension tissue areas. This article presents a simple, predictable, clinically effective, and readily learned functional bilaminar impression technique that will allow dentists to make an anatomically and functionally supported distal extension removable partial denture.

  5. Removable Partial Denture in a Cleft Lip and Palate Patient: A Case Report

    PubMed Central

    Özdemir, Eylem

    2008-01-01

    This clinical report described the oral rehabilitation of a cleft lip and palate patient with removable partial denture. Although implant-supported fixed treatment was presented as part of the optimum treatment plan to achieve the best result, the patient declined this option due to the significant financial burden. Persons with a congenital or craniofacial defect are unique, and oral problems must be evaluated individually to the most ideal treatment. The changes in appearance, function, and psychological wellbeing have an enormous impact on patients' personal lives and are rewarding for the maxillofacial prosthodontist providing this care. PMID:18955808

  6. Provisional prosthetic management of mobile teeth in conjunction with a removable partial denture using orthodontic wire.

    PubMed

    Oh, Won-suk; Saglik, Berna

    2009-10-01

    Precision attachment-retained removable partial dentures eliminate the use of visible clasps and improve the esthetic appearance of the smile; however, terminal abutment teeth may be subject to unfavorable stresses under function when misused. A provisional prosthetic management technique that incorporates an orthodontic wire to assist cross-arch support and stability of the periodontally weakened abutment teeth is described. This technique is simple, reversible, does not alter the esthetic appearance of the smile, and controls the mobility of the abutment teeth until a definitive treatment plan is established.

  7. Swallowed partial dentures

    PubMed Central

    Hashmi, Syed; Walter, John; Smith, Wendy; Latis, Sergios

    2004-01-01

    Swallowed or inhaled partial dentures can present a diagnostic challenge. Three new cases are described, one of them near-fatal because of vascular erosion and haemorrhage. The published work points to the importance of good design and proper maintenance. The key to early recognition is awareness of the hazard by denture-wearers, carers and clinicians. PMID:14749401

  8. Prevalence of removable partial dentures users treated at the Aracatuba Dental School-UNESP.

    PubMed

    Pellizzer, Eduardo P; Almeida, Daniel Augusto de Faria; Falcón-Antenucci, Rosse M; Sánchez, Daniela Mayumi I K; Zuim, Paulo Renato J; Verri, Fellippo R

    2012-06-01

    The aim of this study was to evaluate the frequency of removable partial dentures (RPD) at the Aracatuba Dental School. The study was conducted by analysing 412 clinical history of patients attended at the RPD clinics in the period from 2000 to 2007. 412 charts were analysed: 148 (35.9%) men and 264 (64.1%) women. The mean age was 53.8 years (men) and 52.4 years (women). A total of 556 dentures were made; of these, 233 (41.90%) were maxillary and 323 (58.09%) were mandibular dentures. The most frequent Kennedy classification found was Class III (maxilla) and Class I (mandible). In the maxilla, 55% (126) of the major connectors were of the anterior-posterior palatal bar, while in the mandible, 64% (202) were the lingual bar. As regards the claps, 401 were circumferential and 318 were bar claps. The mean age of the patients was 52.9 years with higher prevalence of female patients; the most frequent Kennedy's classification was Class I in mandible and Class III in maxilla; the most common major connector was anterior-posterior palatal bar for maxilla and lingual bar for mandible; the circumferential clasps were the most common retainer used in both jaws. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  9. Multicentre prospective evaluation of implant-assisted mandibular removable partial dentures: surgical and prosthodontic outcomes.

    PubMed

    Payne, Alan G T; Tawse-Smith, Andrew; Wismeijer, Daniel; De Silva, Rohana K; Ma, Sunyoung

    2017-01-01

    To determine implant survival and prosthodontic maintenance of implant-assisted mandibular removable partial dentures in a multicentre prospective study up to 10 years. Forty-eight participants with mandibular distal extension partial dentures were selected. A control group of 12 New Zealand participants had new conventional mandibular partial dentures made. Three test groups of 36 participants in New Zealand (n = 12), the Netherlands (n = 12) and Colombia (n = 12) had bilateral distal implants placed. Surgical and prosthodontic outcomes were documented with only healing caps placed (Stage 1) and with an attachment system (Stage 2). No implants failed after 3 years. Four late implant failures in three participants occurred in New Zealand (two unilateral implant failures after 5 and 8 years and two bilateral implant failures in the same participant after 6 and 10 years); two unilateral late implant failures occurred in the Netherlands and no late failures in Colombia. Implant survival rate was 92% by 10 years. Resonance frequency measurements were taken at surgery implant stability quotient (ISQ) 62.44 ± 7.46; range 40 - 79), baseline (ISQ 63.22 ± 6.17; range 50 - 74) and after 3 years (ISQ 66.38 ± 6.77; range 55 - 83). In New Zealand and Colombia, measured crestal bone levels were 2.03 ± 0.71 mm and 2.20 ± 0.81 mm, respectively, at baseline and 3 years. For Stage I, principal prosthodontic maintenance issues were loose healing caps among 10 New Zealand participants, four Colombian participants and one Netherlands participant. For Stage 2, matrix activation and overdenture puncture fractures resulted in 41 events (25 participants) in New Zealand over 10 years, whilst over 3 years, there were 14 events in nine Colombian participants and six events in five Netherlands participants. This clinical multicentre research complements previous case reports, case series, retrospective and prospective studies on the notion of implant

  10. [Three-dimensional finite element analysis of removable partial denture with periodontally compromised abutments].

    PubMed

    Wei, Jian; Xu, Bin-ting; Li, Qing; Wang, Yi-ning

    2013-07-01

    To evaluate three-dimensional (3D) finite element (FE) modeling of different periodontally compromised unilateral distal extension removable partial denture (RPD) abutments using the data of a 3D non-contact digitizing scanner. FE models were established, and the following structures were simulated in the models: alveolar bone, mucosa, abutments, periodontal ligaments, framework and artificial teeth. The alveolar bone and periodontal ligaments around the distal abutment in the three models were designed as normal, with bone defect and with periodontal ligaments defect respectively.Vertical or buccally inclined forces of 50, 100, 100 N were applied on the artificial teeth of the RPD and the stress distributions on the supporting tissues were calculated. Under vertical loading, the maximal stress on the alveolar bone of the abutment were as follows: periodontal ligaments defect model (3.57 MPa) > bone defect model (3.21 MPa) > normal model (2.63 MPa). Under buccally inclined loading, the maximal stress on the alveolar bone of the abutment were as follows: periodontal ligaments defect model (2.50 MPa) > bone defect model (2.41 MPa) > normal model (1.79 MPa). Under buccally inclined loading, the stresses on distal aspects of the residual alveolar ridge were higher than that of the vertical loading model. 3D non-contact digitalizing scanner was useful for the finite element modeling process of removable partial denture.

  11. Laser welding of a cobalt-chromium removable partial denture alloy.

    PubMed

    NaBadalung, D P; Nicholls, J I

    1998-03-01

    The electric alloy brazed joints of removable partial denture alloys have failed frequently after routine usage. A technique providing higher joint strengths was investigated. This investigation compared the tensile strengths of electric-brazed and laser-welded joints for a cobalt-chromium removable partial denture alloy. Twenty-four cobalt-chromium standard tensile testing rods were prepared and divided into three groups of eight. All specimens in the control group (group 1) were left in the as-cast condition. Groups 2 and 3 were the test specimens, which were sectioned at the center of the rod. Eight specimens were joined by using electric brazing, and the remaining specimens were joined by using laser welding. After joining, each joint was ground to a uniform diameter, then tested to tensile failure on an Instron universal testing machine. Failure loads were recorded and fracture stress calculated. Statistical analysis was applied. The student-Newman-Keuls test showed a highly significant difference between the joint strengths of the as-cast control specimens, the electric-brazed and laser-welded joints. The tensile strengths of the as-cast joints were higher than those for the laser-welded joints, and both were higher than the electric-brazed joint strengths.

  12. Strain Distribution in a Kennedy Class I Implant Assisted Removable Partial Denture under Various Loading Conditions

    PubMed Central

    Shahmiri, Reza; Aarts, John M.; Bennani, Vincent; Swain, Michael V.

    2013-01-01

    Purpose. This in vitro study investigates how unilateral and bilateral occlusal loads are transferred to an implant assisted removable partial denture (IARPD). Materials and Methods. A duplicate model of a Kennedy class I edentulous mandibular arch was made and then a conventional removable partial denture (RPD) fabricated. Two Straumann implants were placed in the second molar region, and the prosthesis was modified to accommodate implant retained ball attachments. Strain gages were incorporated into the fitting surface of both the framework and acrylic to measure microstrain (μStrain). The IARPD was loaded to 120Ns unilaterally and bilaterally in three different loading positions. Statistical analysis was carried out using SPSS version 18.0 (SPSS, Inc., Chicago, IL, USA) with an alpha level of 0.05 to compare the maximum μStrain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum μStrain was predominantly observed in a buccal direction. As the load was moved anteriorly the μStrain increased in the mesial area. Unilateral loading resulted in a twisting of the structure and generated a strain mismatch between the metal and acrylic surfaces. Conclusions. Unilateral loading created lateral and vertical displacement of the IARPD. The curvature of the dental arch resulted in a twisting action which intensified as the unilateral load was moved anteriorly. PMID:23737788

  13. Clinical application of removable partial dentures using thermoplastic resin-part I: definition and indication of non-metal clasp dentures.

    PubMed

    Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-Ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

    2014-01-01

    This position paper proposes a definition and naming standard for removable partial dentures (RPDs) using thermoplastic resin, and presents a guideline for clinical application. A panel of 14 experts having broad experience with clinical application of RPDs using thermoplastic resin was selected from members of the Japan Prosthodontic Society. At a meeting of the panel, "non-metal clasp denture" was referred as the generic name of RPDs with retentive elements (resin clasps) made of thermoplastic resin. The panel classified non-metal clasp dentures into two types: one with a flexible structure that lacks a metal framework and the other having a rigid structure that includes a metal framework. According to current prosthetic principles, flexible non-metal clasp dentures are not recommended as definitive dentures, except for limited cases such as patients with a metal allergy. Rigid non-metal clasp dentures are recommended in cases where patients will not accept metal clasps for esthetic reasons. Non-metal clasp dentures should follow the same design principles as conventional RPDs using metal clasps. Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  14. Radiographic and metallographic evaluation of porosity defects and grain structure of cast chromium cobalt removable partial dentures.

    PubMed

    Dharmar, S; Rathnasamy, R J; Swaminathan, T N

    1993-04-01

    A study was undertaken to determine the defects in the internal microstructure of clasps of cast chromium cobalt removable partial denture frameworks. Ninety cast frameworks were radiographically evaluated for porosity with an industrial radiographic machine. The grain structure of the clasps was analyzed with an optical photomicroscope before and after various heat treatments. The radiographic study showed a large number of internal defects in various parts of removable partial denture frameworks. The grain structure study revealed microporosities randomly distributed within the matrix. Various heat treatments were performed and resulted in no change in the grain structure of the original castings.

  15. [Developing a plan of treatment with a cast metal frame removable partial denture].

    PubMed

    Witter, D J; Barèl, J C; Keltjens, H M A M; de Baat, C; Creugers, N H J

    2011-02-01

    When considering prosthetic replacement of absent teeth, a treatment plan is necessary. In evaluating whether replacement of teeth is sensible, the causes and consequences of tooth loss must be considered. This concerns information about problems having to do with the patient, potential complications, purely prosthodontic problems, and specific problems. The patient-related problems require collecting data through patient history as well as a clinical and radiologic examination. Complications are risk-factors which negatively influence the prognosis of general health or of a treatment. Potential complications should be eliminated as much as possible through a preliminary treatment. Purely prosthodontic problems are conditions in the area of absence of several teeth or parts of them, and in the area of occlusal and mandibular stability and articulation. Specific problems may be related to inadequate interocclusal space and the quality of the abutment teeth. A cast metal frame removable partial denture may be a relatively inexpensive and minimally treatment alternative for an expensive and complicated treatment with 1 or more fixed partial dentures.

  16. [A new blockout instrument for the construction of rotational path removable partial dentures. A case report].

    PubMed

    Luk, K C; Chen, P S

    1991-03-01

    This article introduces a new blockout device for rotational path removable partial dentures. The concept of rotation axis is discussed, from which a more convenient tool for clinical use is derived. The blockout instrument can be divided into three parts: the acrylic block, the rotation axis and the functional part. In the case of tilted mandibular molars, distal and lingual surfaces of anterior abutments should be blocked out according to the rotational path of insertion. In the blockout procedures, the blockout instrument is mounted between the two rotation centers on the two distal abutments with dental stone, so as to coincide the rotation axis of the instrument and that of the denture to be constructed. After the areas below the survey line of the anterior abutments are aproned with wax, Duralay resin is applied onto the areas above the survey line, and extended to join the functional parts of the blockout instrument. After setting, Duralay resin is removed and the portion above the survey line is trimmed to form a knife edge which corresponds to the survey line. Thereafter, the blockout areas are determined by the rotation movement of the knife-edge shaped Duralay resin along the rotation axis of the blockout instrument. This blockout method is more easily performed compared to the method mentioned by Firtell and Jacobson. In addition to the function of blockout, it can also be assisted in analyzing undercut and diagnosis.

  17. [Three-dimensional finite element analysis of stress distribution about abutments periodontal membranes of separated removable partial denture and conical telescope].

    PubMed

    Tang, Ying; Wang, Min; Luo, Yun; Man, Yi

    2009-10-01

    To investigate and compare the stress of edentulous mucosa and periodontal membranes of the abutments under vertical loads for separated removable partial denture or conical telescope denture. One patient who had lost the second premolar and the first molar on the upper jaw and had I mobile abutments was chosen in the study. Two precise three dimensional finite element models were constructed by using screw CT image reconstruction technique and Materialise Mimics, Pro/Engineer WF 2.0, ANSYS Workbench software. Vertical forces were loaded on the two models. Then comparing and analyzing the von Mises stress distribution of the edentulous mucosa and the periodontal membranes of abutments between the separate removable partial denture and conical telescope denture in the software of ANSYS Workbench. The von Mises stress values of the edentulous mucosa of separate removable partial denture were larger than that of the conical telescope denture. The von Mises stress values of abutments periodontal membranes of separate removable partial denture were lower than that of conical telescope denture. Under vertical loads, compare with conical telescope denture, the separate removable partial denture can protect the abutments.

  18. The effect of implant-supported removable partial dentures on oral health quality of life.

    PubMed

    Gates, W Day; Cooper, Lyndon F; Sanders, Anne E; Reside, Glenn J; De Kok, Ingeborg J

    2014-02-01

    Removable partial dentures (RPDs) represent standard treatment for partial edentulism despite major shortcomings. To alleviate these shortcomings, endosseous implants provide support and stability as well as contribute to maintenance of alveolar bone. This prospective, within subject, time series study evaluated patient-based outcomes of RPDs compared to implant-supported removable partial dentures (ISRPDs). The study hypothesis was that the ISRPD would substantially improve oral health quality of life for patients. Seventeen patients requesting new mandibular Kennedy I or II RPDs received one 6-mm dental implant in one or both of the posterior edentulous areas. After healing, conventional RPDs were fabricated and delivered. Twelve weeks later, second-stage surgery was performed, and ball abutments with Clix attachments were inserted, thereby converting the prostheses to ISRPDs. Oral health quality of life was evaluated using the 49-item Oral Health Impact Profile (OHIP-49) questionnaire. The OHIP-49 was administered prior to treatment (baseline), at 6 and 12 weeks following RPD delivery and at 6 and 12 weeks following ISRPD conversion. Radiographic evaluation was performed at 6 and 12 weeks following ISRPD conversion. In statistical analysis, a fixed-slope random intercept variance components model took account of the multiple observations per person over time. In 17 subjects, 29 of 30 implants survived. The failed implant was replaced without complications. Abutment complications were limited to one abutment loosening and one attachment replacement. Minor prosthodontic complications were recorded. The OHIP-49 score reduced by 11.8 points, on average, at 12 weeks following ISRPD conversion (P = 0.011). Patients reported improved oral health following conversion to an ISRPD from RPD. The ISRPD involving short implants is one treatment option that should be considered when treatment planning Kennedy Class I and II patients. © 2012 John Wiley & Sons A/S.

  19. Additive Manufacturing: A Novel Method for Fabricating Cobalt-Chromium Removable Partial Denture Frameworks.

    PubMed

    Alifui-Segbaya, Frank; Williams, Robert John; George, Roy

    2017-06-01

    Additive manufacturing (AM) often referred to as 3D printing (3DP) has shown promise of being significantly viable in the construction of cobalt-chromium removable partial denture (RPD) frameworks. The current paper seeks to discuss AM technologies (photopolymerization processes and selective laser melting) and review their scope. The review also discusses the clinical relevance of cobalt-chromium RPD frameworks. All relevant publications in English over the last 10 years, when the first 3D-printed RPD framework was reported, are examined. The review notes that AM offers significant benefits in terms of speed of the manufacturing processes however cost and other aspects of current technologies remain a hindrance. Copyright© 2017 Dennis Barber Ltd.

  20. Impression Procedures for Metal Frame Removable Partial Dentures as Applied by General Dental Practitioners.

    PubMed

    Fokkinga, Wietske A; van Uchelen, Judith; Witter, Dick J; Mulder, Jan; Creugers, Nico H J

    2016-01-01

    This pilot study analyzed impression procedures for conventional metal frame removable partial dentures (RPDs). Heads of RPD departments of three dental laboratories were asked to record features of all incoming impressions for RPDs during a 2-month period. Records included: (1) impression procedure, tray type (stock/custom), impression material (elastomer/alginate), use of border-molding material (yes/no); and (2) RPD type requested (distal-extension/tooth-bounded/combination). Of the 132 total RPD impressions, 111 (84%) involved custom trays, of which 73 (55%) were combined with an elastomer. Impression border-molding material was used in 4% of the cases. Associations between impression procedure and RPD type or dentists' year/university of graduation were not found.

  1. Design of removable partial dentures: a survey of dental laboratories in Greece.

    PubMed

    Avrampou, Marianna; Kamposiora, Phophi; Papavasiliou, Georgios; Pissiotis, Argirios; Katsoulis, Joannis; Doukoudakis, Asterios

    2012-01-01

    The aim of this study was to compare data on design and fabrication methods of removable partial dentures (RPDs) in two major cities in Greece. A questionnaire was sent to 150 randomly selected dental technicians. The participation rate was 79.3%. The anterior palatal strap, the lingual bar, and the Roach-type clasp arm designs were preferred. Half of the RPDs fabricated were retained using precision attachments. Differences between the two cities were observed in types of major maxillary connectors used, types of attachments and impression materials used, as well as the design of distal-extension RPDs. Postdoctoral education was found to have an impact on RPD fabrication. Despite the differences observed, design and fabrication of RPDs followed commonly used principles.

  2. A Clinical Retrospective Study of Distal Extension Removable Partial Denture with Implant Surveyed Bridge or Stud Type Attachment

    PubMed Central

    Bae, Eun-Bin; Kim, Seong-Jong; Choi, Jae-Won; Jeon, Young-Chan; Jeong, Chang-Mo; Yun, Mi-Jung; Lee, So-Hyoun

    2017-01-01

    This study was performed to make comparative analysis of the clinical findings between the two different types of the implant-assisted removable partial dentures: removable partial dentures using implant surveyed bridge as an abutment (ISBRPD) and overdenture type of removable partial denture using implant attachment (IARPD). Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated on 24 patients who were treated with implants in conjunction with removable partial denture and have used them for at least 1 year (ISCRPD: n = 12; IARPD: n = 12). There was no failed implant and all implants were functioning without clinical mobility. Marginal bone loss of ISCRPD (1.44 ± 0.57 mm) was significantly lower than that of IARPD (p < 0.05). There was no significant difference in probing depth, peri-implant inflammation, bleeding, and plaque between the two groups (p > 0.05), while the calculus was significantly more observed in ISCRPD group than in IARPD group (p < 0.05). The retention loss of IARPD was the most common complication. Within the limits of the present study, it was found that well-planned ISBRPD was clinically appropriate. Longitudinal and systematic clinical studies are necessary to confirm these results. PMID:28497062

  3. The Use of Telescopic Crowns in Removable Partial Denture Treatment for Patients with Severe Periodontal Disease: Two Patient Case History Reports.

    PubMed

    Cho, Jin-Hyun; Cho, Sung-Am

    2016-01-01

    Two patient case histories are described as examples of treatment of severe periodontitis in severely compromised partial dentitions. Management consisted of periodontal treatment and telescopic crown support for removable partial dentures with friction pin retention.

  4. The influence of heat treatments on several types of base-metal removable partial denture alloys.

    PubMed

    Morris, H F; Asgar, K; Rowe, A P; Nasjleti, C E

    1979-04-01

    Four removable partial denture alloys, Vitallium (Co-Cr alloy), Dentillium P.D. (Fe-Cr alloy), Durallium L.G. (Co-Cr-Ni alloy), and Ticonium 100 (Ni-Cr alloy), were evaluated in the as-cast condition and after heat treatment for 15 minutes at 1,300 degrees, 1,600 degrees, 1,900 degrees, and 2,200 degrees F followed by quenching in water. The following properties were determined and compared for each alloy at each heat treatment condition: the yield strengths at 0.01%, 0.1%, and 0.2% offsets, the ultimate tensile strength, the percent elongation, the modulus of elasticity, and the Knoop microhardness. The results were statistically analyzed. Photomicrographs were examined for each alloy and test condition. The following conclusions were made: 1. The "highest values" were exhibited by the as-cast alloy. 2. Heat treatment of the partial denture alloys tested resulted in reductions in strength, while the elongations varied. This study demonstrates that, in practice, one should avoid (a) prolonged "heat-soaking" while soldering and (b) grinding or polishing of the casting until the alloy is "red hot". 3. Durallium L.G. was the least affected by the various heat treatment conditions. 4. Conventional reporting of the yield strength at 0.2% offset, the ultimate tensile strength, and percent elongation are not adequate to completely describe and compare the mechanical behavior of alloys. The reporting of the yield strength at 0.01% offset, in addition to the other reported properties, will provide a more complete description of the behavior of the dental alloys.

  5. Partial denture-- an ENT surgeon's nightmare.

    PubMed

    Venugopal, M; Sagesh, M

    2012-11-01

    Foreign body oesophagus is one among the common otorhinolaryngology emergencies that we come across. Artificial partial denture impaction in the oesophagus is often an ENT surgeon's nightmare. This study was done in the department of otorhinolaryngology, Government Medical College Kozhikode for a period of 2 years. All patients presented with history of accidental swallowing of partial denture followed by dysphagia. Radiological evaluation was done and subsequently oesophagoscopy and removal of the denture was done. In failed cases exploration and removal of foreign body was required. Complications were found in partial denture with metal wire clasps. It is better to avoid using malfitting dentures with small base, those with metal wire clasps and be cautious of using dentures in alcoholics and unconscious patients.

  6. An ontology-driven, case-based clinical decision support model for removable partial denture design

    NASA Astrophysics Data System (ADS)

    Chen, Qingxiao; Wu, Ji; Li, Shusen; Lyu, Peijun; Wang, Yong; Li, Miao

    2016-06-01

    We present the initial work toward developing a clinical decision support model for specific design of removable partial dentures (RPDs) in dentistry. We developed an ontological paradigm to represent knowledge of a patient’s oral conditions and denture component parts. During the case-based reasoning process, a cosine similarity algorithm was applied to calculate similarity values between input patients and standard ontology cases. A group of designs from the most similar cases were output as the final results. To evaluate this model, the output designs of RPDs for 104 randomly selected patients were compared with those selected by professionals. An area under the curve of the receiver operating characteristic (AUC-ROC) was created by plotting true-positive rates against the false-positive rate at various threshold settings. The precision at position 5 of the retrieved cases was 0.67 and at the top of the curve it was 0.96, both of which are very high. The mean average of precision (MAP) was 0.61 and the normalized discounted cumulative gain (NDCG) was 0.74 both of which confirmed the efficient performance of our model. All the metrics demonstrated the efficiency of our model. This methodology merits further research development to match clinical applications for designing RPDs. This paper is organized as follows. After the introduction and description of the basis for the paper, the evaluation and results are presented in Section 2. Section 3 provides a discussion of the methodology and results. Section 4 describes the details of the ontology, similarity algorithm, and application.

  7. Use of the rotational path removable partial denture concept in a Kennedy Class II patient: a case report.

    PubMed

    Donovan, Terry

    2008-01-01

    This case report describes the treatment of a patient with Sjogren's syndrome who was missing all of the posterior teeth in the maxillary left arch. Implants were contraindicated for this patient because of a chronic sinus infection. Various removable prosthodontic options were considered, and the patient was ultimately treated very conservatively with a rotational path removable partial denture (RPD). This approach required no tooth preparation other than bonding a resin composite cingulum rest on the maxillary left canine. The use of the rotational path RPD eliminated any unsightly clasp assembly display and provided a satisfactory esthetic result. The rotational path removable partial denture is an underutilized option for the esthetic replacement of missing teeth. It should be considered as an option in both tooth-borne and Kennedy Class II situations.

  8. Microbiological risk for periodontitis of abutment teeth in patients with removable partial dentures.

    PubMed

    Mine, K; Fueki, K; Igarashi, Y

    2009-09-01

    Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola are identified as the red complex which exists in high proportions in periodontally diseased patients. The aim of this study was to assess the microbiological risk for periodontitis of abutment teeth in subjects wearing removable partial dentures (RPDs) by measuring the red complex using BANA-ZymeTM test. Thirty-eight subjects (mean age: 62.2 years) with Kennedy Class II partially edentulous arch participated in this study. The red complex and clinical parameters, such as plaque index, gingival index, probing depth and tooth mobility were recorded at abutment teeth in contact with the direct retainer of unilaterally designed RPDs and the corresponding non-abutment teeth on the opposite side. Mean scores for the red complex, plaque index, gingival index and tooth mobility of the abutment teeth were significantly greater than those of the non-abutment teeth (P < 0.01). No significant mean difference in pocket depth was found between the abutment and non-abutment teeth. Logistic regression analysis revealed that abutment teeth, high scores of plaque index and a maintenance interval longer than 6 months were significant predictors for positive red complex scores (P < 0.05). These results suggest that the microbiological risk for periodontitis of abutment teeth is greater than that for non-abutment teeth in RPD wearers.

  9. Attitudes of Victorian dentists to removable partial denture prosthodontics: treatment planning.

    PubMed

    Parker, D A; Harcourt, J K; Cheung, N H

    1989-12-01

    A survey of the attitudes of dentists in Victoria to various aspects of the treatment planning phase of removable partial denture prosthodontics was undertaken. Data were analysed and compared with those obtained from an identical study in South Australia. Those Victorian dentists who graduated in the 1960s, those who worked in multiple-practitioner practices, or non-rural areas, and those who had an added interest in removable prosthodontics were more likely to stress the importance of a greater number of attributes than those who graduated in the 1950s or 1970s, or those who worked alone, in rural areas, or had no particular interest in the discipline. Results indicated also that Victorian dentists tended to place greater emphasis on many of the concepts embraced by the questions asked than their interstate colleagues. It is suggested that, in addition to formal education, intraprofessional relationships and interest in a discipline are factors which might influence the concepts and attitudes of general practitioners.

  10. [Effect of removable partial denture(RDP) generated occlusal interference on masticatory efficiency-A preliminary study

    PubMed

    Ding, L; Yang, C Y; Xu, W J

    1999-06-01

    OBJECTIVE:This study was primarily aimed to observe the effect of RPD-generated occlusal interference on masticatory efficiency.METHODS:In this study,masticatory performances of thirty-six patients treated with removable partial dentures were assessed by peanut-light absorption test before and after occlusal adjustment was performed.Then comparing the differences of masticatory efficiency when occlusal interferences on dentures were present or eliminated.RESULTS:Patients who received occlusal adjustment made significant improvement in their masticatory efficiency (P<0.01). Occlusion appeared to do directly influence chewing ability.CONCLUSION:The results showed that occlusal factor is one of the major factors responsible for denture quality and health of stomatognathic system. Occlusal adjustment is important and necessary in dental prosthesis.

  11. Retrospective audit of patients with advanced toothwear restored with removable partial dentures.

    PubMed

    Woodley, N J; Griffiths, B M; Hemmings, K W

    1996-12-01

    The dental records of 50 patients with advanced tooth wear restored with removable prostheses were examined. Retrospective data were collected with regard to source of referral, presenting complaint, aetiological factors, clinical features, dentures provided, details of failures and maintenance. The maximum follow up period was three years. The ratio of male to female patients was 4:1 and the age range 31-75 years. Failures were recorded in 38% of patients with provisional and 64% with definitive dentures. The most common failure was fracture or wear of the incisal or occlusal surfaces. The majority of failures were addressed by adjustment of the dentures and the audit confirmed the need for regular maintenance.

  12. A comparative study of the centrifugal and vacuum-pressure techniques of casting removable partial denture frameworks.

    PubMed

    Shanley, J J; Ancowitz, S J; Fenster, R K; Pelleu, G B

    1981-01-01

    A study was undertaken to evaluate two techniques for casting accuracy on removable partial denture frameworks: centrifugal casting and vacuum-pressure casting. A standard metal die with predetermined reference points in a horizontal plane was duplicated in refractory investment. The casts were waxed, and castings of nickel-chrome alloy were fabricated by the two techniques. Both the casts and the castings were measured between the reference points with a measuring microscope. With both casting methods, the differences between the casts and the castings were significant, but no significant differences were found between castings produced by the two techniques. Vertical measurements at three designated points also showed no significant differences between the castings. Our findings indicate that dental laboratories should be able to use the vacuum-pressure method of casting removable partial denture frameworks and achieve accuracy similar to that obtained by the centrifugal method of casting.

  13. Quality of materials supplied to dental laboratories for the fabrication of cobalt chromium removable partial dentures in Ireland.

    PubMed

    Lynch, Christopher D; Allen, P Finbarr

    2003-12-01

    The adequacy of prescription for fabrication of cobalt chromium removable partial dentures is often regarded as being less than ideal. This study examines the nature and quality of written instructions and master impression sent to dental laboratories in Ireland for fabrication of cobalt chromium removable partial denture frameworks. Questionnaires were issued to dental laboratories seeking specific information relating to the materials (impression materials and trays) and written instructions supplied, as well as the technicians' opinion regarding the suitability of these materials. One hundred completed questionnaires were returned. One-third of master impressions were made using a plastic stock tray and alginate; technicians felt that one-fifth of master impressions were unsuitable; almost three-fifths of written instructions were inadequate. The quality of clinical information examined was found to be less than adequate.

  14. Effect of anchorage on the accuracy of fit in removable partial denture framework.

    PubMed

    Gowri, Veena; Patil, Narendra P; Nadiger, Ramesh K; Guttal, Satyabodh S

    2010-07-01

    This study evaluated the effect of anchorage on the accuracy of fit in removable partial denture framework. Twenty-four partially edentulous maxillary refractory casts were duplicated from a machine-milled metal cast. Twelve of these were included in the test group, which had the provision for anchorage in the refractory cast, and the remaining 12 were taken as control group, which did not have provision for anchorage. Identical wax patterns for the maxillary strap major connector were invested and cast in cobalt chromium alloy. The accuracy of fit of the cast partial major connector frameworks were measured at two selected points using a profile projector. The resultant data were analyzed using student's t-test and unpaired t-test. Student's t-test showed statistically significant improvement in the fit of the major connectors of the test group at point A (p= 0.0003) and P (p= 0.0074). Unpaired t-test was performed for the control and test group. The results of the unpaired t-test for the control group exhibited a greater gap discrepancy (0.44 +/- 0.20 mm) than for the test group at point A (0.16 +/- 0.10 mm). Similarly, the gap was more at Point P for the specimens in the control group (0.65 +/- 0.10 mm) than the test group (0.42 +/- 0.24 mm). Within the limitations of the study it is concluded that the accuracy of fit of the palatal major connector was significantly better in the test group than the control group, with 0.1% level of significance at point P. The accuracy was significantly improved in both groups at point A by 1% level of confidence.

  15. Occlusal force transfer by removable partial denture designs for a radical maxillectomy.

    PubMed

    Schwartzman, B; Caputo, A; Beumer, J

    1985-09-01

    Several removable partial denture retainers were tested on a photoelastic cast of a human maxilla that had undergone a surgical resection through the midline. The conclusions based on the results of these tests are as follows. Physiologic adjustment of all the designs tested revealed a dramatic reduction in stresses when the framework were placed into position. Under load, the physiologically adjusted frameworks produced less potentially damaging stresses in the supporting structures than the unadjusted frameworks. High stresses were located at the premolar region for all the designs. Lingual retainers produced higher stress concentration than buccal retainers. In the anterior region, the I-bar retainer with a cingulum rest was the best combination for transmitting the occlusal forces along the long axis of the tooth. From the perspective of the equitability of stress transfer, the tested designs from best to worse are infrabulge I-bar retainer, either buccal or lingual retention; light wire circumferential retainer with buccal retention; and the circumferential cast buccal retention, swing-lock system.

  16. Masticatory efficiency of shortened dental arch subjects with removable partial denture: A comparative study.

    PubMed

    Omo, J O; Sede, M A; Esan, T A

    2017-04-01

    The objective of this study was to compare the masticatory efficiency in subjects with shortened dental arch (SDA) before and after restoration with removable partial denture (RPD). This was a prospective study carried out on 36 consecutive patients. The subjects were asked to chew 5 g of a measured portion of fresh raw carrot for 20 specified numbers of strokes. The raw carrot was recovered into a cup and strained through a standard mesh sieve of 5 mm by 1 mm, it was air dried for 30 min and weighed with FEM digital series weighing scale. The masticatory performance ratio was then determined. The age range of the subjects was 34-64 years with the mean age being 52.2 ± 8.2 years. The difference between the total masticatory performance score at the post- and pre-treatment phases was statistically significant (P = 0.001). The improvement in masticatory performance was marked among the younger age groups (P = 0.001), unilateral free end saddle subjects (P = 0.001), and among the male gender (P < 0.05). Masticatory performance improved with the provision of RPD. However, the improvement was marked among the younger age groups, unilateral free end saddle subjects, and the male gender; thereby supporting the need for RPDs in patients with SDA.

  17. Possible variation of the human oral bacterial community after wearing removable partial dentures by DGGE.

    PubMed

    Zhu, Xiao; Wang, Shaohai; Gu, Yihai; Li, Xiaoyu; Yan, Hui; Yan, He; Miyoshi, Shin-Ichi; Shi, Lei

    2012-05-01

    Although it is well-known that variations of the microbial community in a specific location of human body may be associated with some diseases, the developing change of the oral microbiota related to oral diseases before and after wearing the removable partial dentures (RPD) is not completely understood. In this study, three kinds of samples (saliva, supra- and subgingival plaque, and oral mucosal surfaces) were collected from the 10-patients group at three different times: before, 1-month and 6-months after the treatment. Ten healthy adults were also selected as the control group. Denaturing gradient gel electrophoresis was applied to identify the bacterial profiles and to analyze the dynamics of the oral microbial population in the pre- and post-therapy. The ANOVA of Repeated Measurement Data indicated that, in the saliva and mucosal surfaces, wearing RPDs caused significant change of numbers of amplicons. As many as 607 amplicons were chosen to cut out and re-amplify by PCR. After cloning and sequencing, a total of 16 bacterial genera were identified. The health-associated genera such as Streptococcus, Neisseria, Rothia, Corynebacterium, Leptotrichia, Gemella, Veillonella, Selenomona and Actinomyces tended to decrease, whereas the disease-associated species including Streptococcus mutans tended to increase. In general, wearing RPDs influenced the diversity of the bacterial species in the oral microbial ecosystem. It is noteworthy that the oral environment will be changed from the healthy status towards the disease status after the treatment.

  18. Comparative clinical evaluation of removable partial dentures made of two different materials in Kennedy Applegate class II partially edentulous situation

    PubMed Central

    Hundal, Maninder; Madan, Rajesh

    2015-01-01

    Background Cast Chromium Cobalt alloy has been the material of choice for fabricating Removable Partial Dentures (RPDs) but has certain drawbacks. Newer materials like the flexible Nylon based Super Polyamide have been introduced to overcome these drawbacks. The present study has compared the above two materials for nine clinical parameters. Method The study was carried out on 30 patients presenting with a Kennedy Applegate class II partially edentulous situation who were divided into two equal groups and clinically assessed. Result Statistically significant results were obtained in favor of flexible RPDs, in the parameters of ‘aesthetics’ and ‘overall patient satisfaction’. Both groups showed more or less similar values for ‘frequency of fracture of the prosthesis during usage’ with the incidence being slightly higher for patients wearing the cast RPDs. The clinical parameters of ‘oral soft tissue tolerance’, ‘gingival health’, ‘periodontal health’ and ‘adaptability in areas with undercut’ were statistically at par for all the 30 patients thus suggesting the comparable biocompatibility of the two materials. The highlight of this study was the relative ease in fabrication of the flexible RPDs as compared to the cast RPDs. Conclusion Based on the favorable clinical results of this study, it can be summarized that the flexible RPDs is a viable alternative to cast RPDs in Kennedy Applegate class II partially edentulous situation in the short term. PMID:26843744

  19. Finite element analysis of an implant-assisted removable partial denture.

    PubMed

    Shahmiri, Reza; Aarts, John M; Bennani, Vincent; Atieh, Momen A; Swain, Michael V

    2013-10-01

    This study analyzes the effects of loading a Kennedy class I implant-assisted removable partial denture (IARPD) using finite element analysis (FEA). Standard RPDs are not originally designed to accommodate a posterior implant load point. The null hypothesis is that the introduction of posteriorly placed implants into an RPD has no effect on the load distribution. A Faro Arm scan was used to extract the geometrical data of a human partially edentulous mandible. A standard plus regular neck (4.8 × 12 mm) Straumann® implant and titanium matrix, tooth roots, and periodontal ligaments were modeled using a combination of reverse engineering in Rapidform XOR2 and solid modeling in Solidworks 2008 FEA program. The model incorporated an RPD and was loaded with a bilateral force of 120 N. ANSYS Workbench 11.0 was used to analyze deformation in the IARPD and elastic strain in the metal framework. FEA identified that the metal framework developed high strain patterns on the major and minor connectors, and the acrylic was subjected to deformation, which could lead to acrylic fractures. The ideal position of the neutral axis was calculated to be 0.75 mm above the ridge. A potentially destructive mismatch of strain distribution was identified between the acrylic and metal framework, which could be a factor in the failure of the acrylic. The metal framework showed high strain patterns on the major and minor connectors around the teeth, while the implant components transferred the load directly to the acrylic. © 2013 by the American College of Prosthodontists.

  20. Evaluation of Team-Based Learning and Traditional Instruction in Teaching Removable Partial Denture Concepts.

    PubMed

    Echeto, Luisa F; Sposetti, Venita; Childs, Gail; Aguilar, Maria L; Behar-Horenstein, Linda S; Rueda, Luis; Nimmo, Arthur

    2015-09-01

    The aim of this study was to evaluate the effectiveness of team-based learning (TBL) methodology on dental students' retention of knowledge regarding removable partial denture (RPD) treatment. The process of learning RPD treatment requires that students first acquire foundational knowledge and then use critical thinking skills to apply that knowledge to a variety of clinical situations. The traditional approach to teaching, characterized by a reliance on lectures, is not the most effective method for learning clinical applications. To address the limitations of that approach, the teaching methodology of the RPD preclinical course at the University of Florida was changed to TBL, which has been shown to motivate student learning and improve clinical performance. A written examination was constructed to compare the impact of TBL with that of traditional teaching regarding students' retention of knowledge and their ability to evaluate, diagnose, and treatment plan a partially edentulous patient with an RPD prosthesis. Students taught using traditional and TBL methods took the same examination. The response rate (those who completed the examination) for the class of 2013 (traditional method) was 94% (79 students of 84); for the class of 2014 (TBL method), it was 95% (78 students of 82). The results showed that students who learned RPD with TBL scored higher on the examination than those who learned RPD with traditional methods. Compared to the students taught with the traditional method, the TBL students' proportion of passing grades was statistically significantly higher (p=0.002), and 23.7% more TBL students passed the examination. The mean score for the TBL class (0.758) compared to the conventional class (0.700) was statistically significant with a large effect size, also demonstrating the practical significance of the findings. The results of the study suggest that TBL methodology is a promising approach to teaching RPD with successful outcomes.

  1. Prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients wearing bimaxillary complete dentures, removable partial dentures and in students with natural dentition.

    PubMed

    Bordin, Thaisa B; Conci, Ricardo A; Pezzini, Maristela M G; Pezzini, Rolando P; Mendonça, Márcio J

    2013-01-01

    Temporomandibular Disorder (TMD) has attained a prominent role within the context of dental care due to its high prevalence. The aim of this study was to evaluate the prevalence of signs and symptoms of TMD in students at the State University of West of Paraná (UNIOESTE) with natural dentition, and in patients with removable partial dentures and double complete dentures. A total of 210 randomly selected individuals of both genders were evaluated, being divided into three groups: seventy students at the UNIOESTE with natural dentition (Group 1), seventy patients with removable partial dentures (Group 2) and seventy patients with bimaxillary complete dentures (Group 3). The data were collected by a single examiner using the American Academy of Orofacial Pain questionnaire for triage, where a single affirmative response to any of the situations mentioned was enough to carry out clinical evaluation. Kolmogorov Smirnov, Mann Whitney, Chi-Square, ANOVA and Tukey's statistical tests were performed. The most prevalent signs and symptoms of TMD in Group 1 were pain or difficulty in chewing or talking, perception of recent change in bite and deviations during the course of mandibular movements. In Group 2 they were perceptions of recent changes in the bite, deflections in the mandibular movements, presence of joint sounds, pain during excursive movements and muscle tenderness. The most prevalent signs and symptoms in Group 3 were limited to mouth opening and poor stability and retention of at least one of the prostheses. Group 3 also reported having received treatment for headaches or facial pain with a high prevalence. Group 2 had the highest prevalence of signs and symptoms. Prevalence was similar in Groups 1 and 3.

  2. Shape Optimization for Additive Manufacturing of Removable Partial Dentures - A New Paradigm for Prosthetic CAD/CAM

    PubMed Central

    2015-01-01

    With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption. PMID:26161878

  3. Shape Optimization for Additive Manufacturing of Removable Partial Dentures--A New Paradigm for Prosthetic CAD/CAM.

    PubMed

    Chen, Junning; Ahmad, Rohana; Suenaga, Hanako; Li, Wei; Sasaki, Keiichi; Swain, Michael; Li, Qing

    2015-01-01

    With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption.

  4. Effect of different cleansers on the surface of removable partial denture.

    PubMed

    Felipucci, Daniela Nair Borges; Davi, Letícia Resende; Paranhos, Helena Freitas Oliveira; Bezzon, Osvaldo Luiz; Silva, Rodrigo Ferreira; Pagnano, Valéria Oliveira

    2011-01-01

    Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey's test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.

  5. A comparison between videotaped and live demonstrations, for the teaching of removable partial denture procedures.

    PubMed

    Packer, M E; Rogers, J O; Coward, T J; Newman, P S; Wakeley, R

    2001-02-01

    This study was devised to test the effectiveness of videotaped demonstrations as opposed to live demonstrations, to small groups of undergraduate dental students. The outcome was assessed by comparing the students' understanding of the clinical and laboratory technical stages of the altered cast impression technique, which is used in the construction of removable partial dentures. 31 students watched a series of videotaped demonstrations and 30 received a similar series of live demonstrations. The altered cast procedure was divided into 5 distinct stages, each of which was assessed with the aid of agreed criteria, initially by the students and then by 2 staff assessors and these results were compared. The students were subsequently asked to rate how helpful the videotaped or live demonstration had been on a 5-point scale. The live demonstration group showed better agreement between the students' assessment and the assessors' assessment of the quality of the work for the first part of the clinical stage. There was no difference in the groups' assessment of the final outcome of this clinical stage and the subsequent laboratory technical stages. Students who observed the live demonstrations indicated higher scores for its helpfulness in performance of all the stages of the technique, when compared to those who had observed a videotaped demonstration. Both teaching methods developed a similar level of understanding of the principles behind the exercise, although the students preferred the live demonstrations. A carefully produced videotaped demonstration can be a useful alternative to a live demonstration in teaching the short and clear cut technique selected for this study.

  6. Analysis of the condyle/fossa relationship before and after prosthetic rehabilitation with maxillary complete denture and mandibular removable partial denture.

    PubMed

    Amorim, Vânia Cristina Pintaudi; Laganá, Dalva Cruz; de Paula Eduardo, José Virgilio; Zanetti, Artemio Luiz

    2003-05-01

    The influence of the loss of posterior teeth on the condylar position and on temporomandibular disorders (TMDs) remains a controversial issue. This study investigated whether prosthetic rehabilitation promoted modification of the condylar position in subjects without symptoms of TMDs. The temporomandibular joints (TMJs) of 12 women (age 37 to 74), all with existing maxillary complete dentures but no removable partial denture (RPD) restoring the Kennedy class I partially edentulous mandibular arch and no clinical signs of TMDs according to the criteria established by Helkimo, were viewed in maximal intercuspal position with corrected lateral tomography before and after prosthetic rehabilitation with a new maxillary complete denture and a mandibular RPD. Before prosthetic rehabilitation, a mandibular stabilizing base was fabricated to prevent the existing maxillary complete denture from dislodging during tomographic examination. Two methods were used to evaluate tomograms: (1) linear measurements of the subjective narrowest anterior and posterior intra-articular joint spaces made from the tomograms by use of a digital caliper and (2) linear measurements of the anterior and posterior intra-articular joint spaces on the basis of drawings and tracings. Repeated-measures analysis of variance followed by orthogonal contrasts were used to evaluate differences between measurements carried out on the same subject under the different test conditions of the study (before prosthetic rehabilitation, before prosthetic rehabilitation with a mandibular stabilizing base in position, and after prosthetic rehabilitation) (P<.05). Before prosthetic rehabilitation, a predominance of posterior condylar positions was observed. Before prosthetic rehabilitation with a mandibular stabilizing base in position, a significant decrease was observed in posterior condylar positions (P=.03). This decrease was more marked after prosthetic rehabilitation (P=.02). The subjective evaluation and

  7. A Combination of Various Technologies in the Fabrication of a Removable Partial Denture--A Case Study.

    PubMed

    Seitz, Stefanie; Cox, Nicholas; Jones, John D; Zimmermann, Richard

    2016-01-01

    Digital dentistry is increasing prevalent throughout general dental practice. Scanned impression systems, CAD/CAM software, milling units, and 3D printers are becoming used with regularity by some private practitioners. This case report describes a combination of multiple technologies including intraoral scanning, 3D printing, and traditional impression and processing techniques used for fabricating a removable partial denture. The patient indicated that he was highly satisfied throughout the course of treatment and especially with the final result. Future technology will continue to evolve and be more widely used in removable prosthodontics and other areas of dentistry.

  8. The conversion partial denture: a clinical report.

    PubMed

    Waliszewski, Michael P; Brudvik, James S

    2004-04-01

    The treatment alternative described maximizes the benefit of remaining teeth while allowing simplified alteration of the prosthesis if abutments are lost during the life span of the removable partial denture (RPD). A conversion partial is an RPD whose tooth-frame assembly components are individually fabricated and then joined with an acrylic resin major connector. The conversion RPD optimizes retention and stabilization of a terminal dentition and can be easily converted to an immediate complete denture.

  9. Evaluation of cobalt, chromium, and nickel concentrations in plasma and blood of patients with removable partial dentures.

    PubMed

    Denizoğlu, Saip; Duymuş, Zeynep Yeşil

    2006-06-01

    This study assessed the plasma and blood concentrations of Cr, Co, and Ni among subjects using removable partial dentures. A comparison was made between subjects with and without RPD treatment history. Control group consisted of 10 healthy individuals without dentures. Concentrations of Cr, Co, and Ni in subjects' plasma and blood were measured with an atomic absorption spectrophotometer. Data were statistically analyzed by ANOVA, and multiple comparison test (alpha = 0.05) was used to identify significant differences between groups. RPD use had a significant effect on the concentrations of Cr (P < 0.001) and Ni (P < 0.05) in blood and plasma. As such, there were statistically significant differences between the control and study groups for the concentrations of Cr and Ni in blood and plasma. However, RPD use exhibited no significant effect on Co concentration in plasma. In conclusion, the use of removable partial dentures with metal frameworks led to an increase in the concentrations of Cr and Ni in both blood and plasma.

  10. Rotational path removable partial denture (RPD): conservative esthetic treatment option for the edentulous mandibular anterior region: a case report.

    PubMed

    Suh, Jennifer S; Billy, Edward J

    2008-01-01

    It can be esthetically and financially daunting for patients to lose teeth in an anterior region of the mouth. For these patients, traditional treatment options presented in the past have included fixed partial denture, implants, and conventional removable partial denture (RPD). For patients faced with financial, anatomical, and/or esthetic limitations, the edentulous region can be restored successfully with a rotational path RPD. Rotational path RPD designs have often been overlooked by the dental profession due to its complex concepts involving the prosthetic design and sensitive laboratory techniques. With better understanding of the concepts and design, the dental clinician can deliver the highest esthetic outcome in compromised areas in which other treatment options may often face limitations. This paper reviews the method used to esthetically design and plan a posterior-anterior rotational path RPD in an edentulous mandibular anterior region for a patient missing the mandibular incisors. Due to inadequate understanding of the mechanics of rotational path RPDs, many clinicians have not adapted the application of this advantageous prosthesis. When correctly designed and fabricated, the rotational path RPD provides improved esthetics, cleanliness, and retention for patients who may not be suitable candidates for implants or fixed partial dentures in tooth-supported edentulous regions.

  11. An implant-supported removable partial denture for a patient with post-inflammatory scar contracture caused by burn complications: a clinical report

    PubMed Central

    Kim, Jee-Hwan

    2012-01-01

    The scars and contracture around the oral-facial region may cause difficulty in prosthodontic treatment to restore esthetics and function for the patients, who suffered severe burns. This article presents a technique that uses a fixed partial denture prepared with a conventional milling technique and an attachment to support anterior cantilever removable partial denture, thereby providing a more esthetically acceptable and functional result. PMID:22439102

  12. Trial fitting of a removable partial denture framework made using computer-aided design and rapid prototyping techniques.

    PubMed

    Bibb, R J; Eggbeer, D; Williams, R J; Woodward, A

    2006-10-01

    Previous studies of CAD/CAM-produced sacrificial patterns for removable partial denture frameworks have been documented but to date, no such restorations have been test-fitted to a patient. This paper provides details of the first trial fitting to a patient of an RPD framework, the sacrificial pattern of which was produced by CAD/CAM and RP technologies. A cast of the patient was scanned and the normal procedures of dental surveying and pattern build were undertaken with reference to the scanned model using computer-aided design. A sacrificial pattern of the design was produced by rapid prototyping technology. After spruing the pattern, investment-casting and finishing techniques were carried out according to conventional principles. The framework was successfully trial-fitted to the patient and clinically judged to be acceptable for the next stage of denture fabrication, that of adding acrylic bases and artificial teeth.

  13. Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part I: Methodology and comparisons between treatment groups at baseline.

    PubMed

    Kapur, K K

    1987-10-01

    This study was conducted to determine whether fixed partial dentures supported by dental implants provide an acceptable alternative to conventional removable partial dentures in patients with Kennedy class I or class II edentulous conditions. The acceptability of the new treatment will be based on success rates, impact on the health of the remaining dentition, masticatory performance, patient satisfaction, and maintenance care and cost. The study was planned also to provide comparisons between two designs commonly used by dentists for fabricating removable partial dentures. The designs differed only in terms of the type of the retainer (clasp type) and tooth support (rest location). A total of 272 patients with Kennedy class I and class II edentulous conditions were assigned on a random basis to one of the treatment groups, 134 to receive a removable partial denture and 138 a fixed partial denture supported by a blade-vent implant. All of the patients were medically screened and met prespecified criteria for oral hygiene, bone support for abutment teeth, and size of the residual ridge. Thirty-four patients were eliminated from the study before completion of their treatment. An additional six patients with early implant failures were reentered in the study and followed up as a separate group. The remaining 232 patients received comprehensive dental care, including removable partial dentures for 118 and fixed partial dentures for 114 patients. A series of examinations, radiographs, masticatory performance tests, patient satisfaction, food selection questionnaires, and dietary history were completed before initiation of the treatment, 16 weeks after the insertion of an RPD or an implant, and thereafter at 6-, 18-, 36-, and 60-month intervals. In addition, patients were seen at 6-month intervals for a recall dental examination, oral prophylaxis, plaque instructions, radiographic survey of the implant, and any needed dental treatment. The randomization stratification

  14. Managing the maxillary partially edentulous patient with extensive anterior tooth loss and advanced periodontal disease using a removable partial denture: a clinical report.

    PubMed

    Ma, Polly S; Brudvik, James S

    2008-10-01

    The treatment modality, a continuous occlusal rest removable partial denture, not only restored missing teeth but also stabilized the remaining dentition in a patient with advanced periodontal attachment loss. By engaging the guiding planes at the mesial surfaces of the abutments anteriorly and also the distal surfaces of the abutments posteriorly, the remaining teeth, with varying amounts of mobility, were splinted together by the framework. This conservative treatment option allows flexibility for easy repair during the life span of the prosthesis.

  15. Maxillary rehabilitation using a removable partial denture with attachments in a cleft lip and palate patient: a clinical report.

    PubMed

    Palmeiro, Marina Rechden Lobato; Piffer, Caroline Scheeren; Brunetto, Vivian Martins; Maccari, Paulo César; Shinkai, Rosemary Sadami Arai

    2015-04-01

    Clefts of the lip and/or palate (CLP) are oral-facial defects that affect health and overall quality of life. CLP patients often need multidisciplinary treatment to restore oral function and esthetics. This paper describes the oral rehabilitation of a CLP adult patient who had maxillary bone and tooth loss, resulting in decreased occlusal vertical dimension. Functional and cosmetic rehabilitation was achieved using a maxillary removable partial denture (RPD) attached to telescopic crowns. Attachment-retained RPDs may be a cost-effective alternative for oral rehabilitation in challenging cases with substantial loss of oral tissues, especially when treatment with fixed dental prostheses and/or dental implants is not possible.

  16. A critically appraised topic review of computer-aided design/computer-aided machining of removable partial denture frameworks.

    PubMed

    Lang, Lisa A; Tulunoglu, Ibrahim

    2014-01-01

    A critically appraised topic (CAT) review is presented about the use of computer-aided design (CAD)/computer-aided machining (CAM) removable partial denture (RPD) frameworks. A systematic search of the literature supporting CAD/CAM RPD systems revealed no randomized clinical trials, hence the CAT review was performed. A PubMed search yielded 9 articles meeting the inclusion criteria. Each article was characterized by study design and level of evidence. No clinical outcomes research has been published on the use of CAD/CAM RPDs. Low levels of evidence were found in the available literature. Clinical research studies are needed to determine the efficacy of this treatment modality.

  17. Application of the rotational path design concept to a removable partial denture with a distal-extension base.

    PubMed

    Asher, M L

    1992-10-01

    Biomechanical considerations for use of the rotational path design concept to construct a removable partial denture for a patient with a tooth-bounded ridge on one side and a distal-extension ridge on the opposite side are presented. The various axes and arcs of rotation that occur during masticatory function are identified and their effects on the prosthesis and supporting structures are analyzed. Sequential steps in the necessary surveys of the master cast are enumerated. Critical details for the most effective and least deleterious placement of the rigid retentive element on the mesial surface of the posterior molar abutment (on the tooth-bounded ridge) are described.

  18. Improving the esthetic replacement of missing anterior teeth: interaction between periodontics and a rotational path removable partial denture.

    PubMed

    Goncalves, Leticia Machado; Bezerra-Junior, Jose Ribamar Sabino; Benatti, Bruno Braga; Santana, Ivone Lima

    2011-01-01

    The rotational path of insertion concept for removable partial dentures (RPDs) can be used in esthetically demanding situations. This clinical report describes the treatment of a patient with an anterior maxillary edentulous area using a rotational path RPD. To optimally improve gingival esthetics and to allow proximal retention on the surveyors, a crown-lengthening surgical procedure was performed prior to prosthetic treatment on all teeth involved in this rehabilitation. When correctly planned and fabricated, this prosthesis allows excellent functional and esthetic results, minimizes tooth preparation, and reduces the tendency toward plaque accumulation.

  19. Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part IV: Comparisons of patient satisfaction between two treatment modalities.

    PubMed

    Kapur, K K

    1991-10-01

    This study compares treatment assessments made by two groups of patients with Kennedy class I or class II mandibular edentulous conditions, who received either a removable partial denture (RPD) (N = 115) or one or two fixed partial dentures (FPDs), each supported distally by a blade implant (N = 113). Two questionnaires were administered, one at 16 weeks after the implant or RPD insertion and at the 6-month interval and the other at 18, 36, and 60 months. Marked functional improvements were perceived by a large majority of patients in both groups after the insertion of prosthesis. At 6 months, a higher percent of patients with RPDs than those with FPDs found it easy to clean their RPDs and experienced chewing discomfort, restriction of food choices, feeling of insecurity with their RPDs, and difficulty with their pronunciation. The exclusion of assessments by 25 RPD patients, whose treatment was judged to be a failure functionally, made the mean differences between the two treatments statistically significant (p less than 0.05) only for ease of cleaning in favor of the RPD and fewer restrictions of food choices in favor of the FPD group. At 60 months, significant differences between the percents of patients with the most favorable responses occurred for perceptions of eating enjoyment, food particles seldom getting under the removable partial denture, and improvement in social life in favor of the FPD treatment and for the ease of cleaning the removable partial denture in favor of the RPD treatment. The results seem to support superiority of the FPD in terms of patient satisfaction, but not enough to favor this type of prosthesis over the RPD without consideration of other pertinent factors.

  20. Resin-bonded castings with a cingulum rest seat and a guide plane for a removable partial denture: a case report.

    PubMed

    Shimizu, Hiroshi; Takahashi, Yutaka; McKinney, Thomas

    2008-01-01

    This case report describes the clinical and laboratory procedures used to fabricate resin-bonded castings with cingulum rest seats and guide planes for a removable partial denture using a noble metal alloy (silver-palladium-copper-gold alloy), a metal conditioner (V-Primer, Sun Medical), and an adhesive resin-luting agent (Super-Bond C and B, Sun Medical). The castings have been functioning for more than 11 years. The use of resin-bonded castings with cingulum rest seats for support and a guide plane to brace removable partial dentures is a successful method of treatment.

  1. Management of long span partially edentulous maxilla with fixed removable denture prosthesis

    PubMed Central

    Jeyavalan, Mahilan I.; Narasimman, M.; Venkatakrishnan, C. J.; Philip, Jacob M.

    2012-01-01

    Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis. PMID:23293488

  2. [Transient removable dentures].

    PubMed

    Kouadio, A A; Jordana, F; N'Goran, J K; Le Bars, P

    2015-09-01

    Removable dentures are always transient current. The epidemiology and causes of tooth gaps demonstrate the need to master the different prosthetic treatment. This made whether to propose treatment plans that take into account psychological, physiological and technical support for this patient. Different situations may arise. A gradual transition may be considered or immediate passage to the total edentulous according to general criteria, local and desiderata of patients. After tooth extraction, the transitional prosthesis can control bone lysis thereby it is part of a complete treatment before prosthesis. It also facilitates a good psychological and physiological integration before the prosthesis use.

  3. A survey of removable partial denture casts and major connector designs found in commercial laboratories, Athens, Greece.

    PubMed

    Polychronakis, Nick; Sotiriou, Michael; Zissis, Alcibiades

    2013-04-01

    This survey was conducted to study the prevalence of partial edentulism, the type of removable partial denture (RPD) support, the type of major connectors, and the frequency of their use in relation to the partial edentulism classes encountered, concerning patients in Athens, Greece. The material comprised 628 final casts for RPDs. Each cast was photographed in a way that would allow the number of existing teeth, the classification of partial edentulism, the RPD support, and the particular parts of the metal framework to be identified. Data collected were analyzed statistically using prevalence tables and the χ(2) test. Two hundred seventy six (43.9%) casts were for the maxilla and 352 (56.1%) for the mandible. The most frequently encountered group was Kennedy class I for both arches, while class IV was the classification least encountered (p < 0.001). Of all RPDs constructed, 96.8% had a metal framework (tooth-borne and tooth/tissue-borne), while 3.2% of the RPDs were frameless (tissue-borne, acrylic dentures). The U-shaped palatal connector (horseshoe) in the maxilla and the lingual bar in the mandible were the most frequently used for all partial edentulism classes, at 55.2% and 95%, respectively. Analysis of the casts revealed that the type of major connectors selected does not comply with the indications for their applications, considering the lack of dental history and clinical examination. This notes the need for further training dentists and dental technicians in aspects of RPD framework design. © 2013 by the American College of Prosthodontists.

  4. Satisfying esthetic demands with rotational path partial dentures.

    PubMed

    Jacobson, T E

    1982-09-01

    A description of the rotational path design concept for removable partial dentures has been presented. Through the combined efforts of the clinician and laboratory technician, a rotational path partial denture can be developed that meets the basic mechanical requirements and eliminates certain clasp arms. The primary advantages of this design include less display of metal, enhancing the patient's appearance, and decreased tooth and tissue coverage by partial denture framework components.

  5. [Dual insertion paths design characteristics and short-term clinical observation of rotational path removable partial dentures].

    PubMed

    Li, Jian; Jiang, Ting; Li, Sai; Chen, Wei

    2013-02-18

    To investigate design methods of dual insertion paths and observe a short-term clinic overview of rotational path removable partial dentures (RPDs). In the study, 40 patients with partial edentulous arches were included and divided into two groups. The patients in group one were restored with rotational path RPDs (10 Kennedy class III and 10 Kennedy class IV respectively). The patients in group two (20 patients), whose edentulous area was matched with the patients' in group one, were restored with the linear path RPDs. After surveying and simulative preparation on diagnostic casts, the basic laws of designing rotational path RPDs were summarized. The oral preparation was accurately performed under the guidance of indices made on diagnostic casts after simulative preparation. The 40 dentures were recalled two weeks and one year after the insertion. The evaluations of the clinic outcome, including retention, stability, mastication function, esthetics and wearing convenience, were marked out as good, acceptable, and poor. The comparison of the evaluation results was performed between the two groups. In the rotational path design for Kennedy class III or IV RPDs, the angles (α) of dual insertion paths should be designed within a scope, approximate 10°-15°.When the angle (α) became larger, the denture retention turned to be better, but accordingly the posterior abutments needed more preparation. In the clinical application, the first insertions of the 40 dentures were all favorably accomplished. When the rotational path RPDs were compared to linear path RPDs, the time consuming on first insertion had no statistical difference[(32±8) min and (33±8) min respectively, P>0.05]. Recalled two weeks and one year after the insertion, in the esthetics evaluation, 20 rotational path RPDs were all evaluated as "A", but only 7(two weeks after) and 6 (one year after) linear path RPDs were evaluated as "A"(P<0.05). There was no significant difference in other evaluation results

  6. Tooth preparation for rest seats for cobalt-chromium removable partial dentures completed by general dental practitioners.

    PubMed

    Rice, J A; Lynch, C D; McAndrew, R; Milward, P J

    2011-01-01

    The aim of this project was to examine tooth preparations made by general dental practitioners (GDPs) for occlusal and cingulum rest seats for cobalt-chromium removable partial dentures (RPDs). Master casts and prescribed denture designs for cobalt-chromium RPDs produced by a commercial dental laboratory from impressions made by 45 GDPs across Wales were evaluated over a period of 5 months. Rest seats and associated interocclusal clearances were assessed using pre-determined criteria. A total of 68 casts were examined. Of these, 33 did not have rest seats included in their prescription. Of the remaining 35 casts, 81 rests had been prescribed of which only 24 (30%) had signs of tooth preparations for these rest seats. Using pre-determined criteria, 60% of rest seats were under-prepared in the mesio-distal plane and 30% were over-prepared in the bucco-lingual plane. In 17 cases where natural teeth opposed the rest seat, the mean interocclusal clearance was 1·5 mm (range 0·6-3·5 mm) with 6 of the 17 rests (35%) being less than the recommended thickness. In total, 18 of the 24 rests prepared did not meet the criteria, and 11 of the 21 rests prescribed had no obvious preparation and insufficient occlusal clearance. Where prescribed, the majority of rests did not meet the identified criteria. The rest seat preparations varied greatly in all planes including the interocclusal clearance. Further emphasis should be given to aspects of denture design in undergraduate and continuing education programmes for dentists.

  7. Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study.

    PubMed

    Felipucci, Daniela N B; Davi, Letícia R; Paranhos, Helena F O; Bezzon, Osvaldo L; Silva, Rodrigo F; Barbosa Junior, Fernando; Pagnano, Valéria O

    2011-10-01

    Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5% significance level. Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. It may be concluded that 0.05% NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care.

  8. Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study

    PubMed Central

    FELIPUCCI, Daniela N.B.; DAVI, Letícia R.; PARANHOS, Helena F.O.; BEZZON, Osvaldo L.; SILVA, Rodrigo F.; BARBOSA JUNIOR, Fernando; PAGNANO, Valéria O.

    2011-01-01

    Objective Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. Material and Methods Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5% significance level. Results Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. Conclusions It may be concluded that 0.05% NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care. PMID:21986653

  9. Factors that augment the role of direct retainers in mandibular distal-extension removable partial dentures.

    PubMed

    Donahue, T J

    1988-12-01

    Several features of RPD design that augment direct retainer design were identified. They are as follows: 1. The duplication of direct retainer function by other prosthesis components 2. Physiologic adjustment of the framework to assure contacts with abutment teeth that are consistent with the design and intended functions of the components and that transfer stress in a manner those teeth are designed to accept 3. Intimate adaptation of denture bases to the residual mucosa, with recall visits to monitor this adaptation 4. Specific loading of the denture bases through selective placement of artificial teeth 5. Splinting of abutment teeth

  10. Denture-handling ability of elderly persons with dementia: examination of time spent inserting and removing dentures.

    PubMed

    Kubo, Kin-ya; Iinuma, Mitsuo; Shibutani, Toshiaki; Ito, Masaki; Iwaku, Fumihiko

    2007-01-01

    To evaluate the effects of dementia on denture-handling ability, we measured the amount of time that elderly subjects spent inserting and removing dentures. Elderly subjects with dementia tended to take more time inserting and removing dentures than those who were not demented. Only elderly patients who were severely demented needed significantly more time removing partial dentures than they did removing complete dentures. There was no significant difference between the time spent inserting dentures and removing dentures. The greater amount of time required to insert or remove dentures for subjects with dementia was due to disorientation. The results indicate that elderly people with mild to moderate dementia are able to insert and remove their dentures without help.

  11. The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth

    PubMed Central

    Dula, Linda J.; Shala, Kujtim Sh.; Pustina–Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F.

    2015-01-01

    Objective: The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. Materials and Methods: A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P < 0.05). Results: The mean scores for PLI, CI, BOP, PD, and TM index, of the abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05). Conclusions: With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases. PMID:26430367

  12. [A case of swallowing a lower partial denture].

    PubMed

    Carbery, A; Provençal, M

    1993-10-01

    This paper reports on the case of an elderly person who accidentally swallowed his partial denture. The ingestion did not result in any signs or symptoms and the denture was found totally by chance. A major surgical procedure was required to remove the prosthesis.

  13. Glass fiber reinforcement in repaired acrylic resin removable dentures: preliminary results of a clinical study.

    PubMed

    Vallittu, P K

    1997-01-01

    The clinical usefulness of continuous E-glass partial fiber reinforcement of acrylic resin removable dentures was evaluated an average 13 months after the insertion of the fibers. Twelve removable complete dentures and ten removable partial dentures with a history of recurrent fracture were selected for this study. The partial fiber reinforcement was incorporated into the denture at the time of repair. One complete denture and one removable partial denture fractured in the region of reinforcement during the examination period. These fractures were most likely caused by faulty placement of the fiber reinforcement in the denture in the dental laboratory. In six dentures, new fractures occurred in regions without partial fiber reinforcement. The results revealed the importance of both the correct positioning of the partial fiber reinforcement in the denture and the use of accurate laboratory techniques.

  14. Influence of posterior dental arch length on brain activity during chewing in patients with mandibular distal extension removable partial dentures.

    PubMed

    Shoi, K; Fueki, K; Usui, N; Taira, M; Wakabayashi, N

    2014-07-01

    It is well known that shortened dental arch decreases masticatory function. However, its potential to change brain activity during mastication is unknown. The present study investigates the effect of a shortened posterior dental arch with mandibular removable partial dentures (RPDs) on brain activity during gum chewing. Eleven subjects with missing mandibular molars (mean age, 66.1 years) on both sides received experimental RPDs with interchangeable artificial molars in a crossover trial design. Brain activity during gum chewing with RPDs containing (full dental arch) and lacking artificial molars (shortened dental arch) was measured using functional magnetic resonance imaging. Additionally, masticatory function was evaluated for each dental arch type. Food comminuting and mixing ability and the perceived chewing ability were significantly lower in subjects with a shortened dental arch than those with a full dental arch (P < 0.05). Brain activation during gum chewing with the full dental arch occurred in the middle frontal gyrus, primary sensorimotor cortex extending to the pre-central gyrus, supplementary motor area, putamen, insula and cerebellum. However, middle frontal gyrus activation was not observed during gum chewing with the shortened dental arch. These results suggest that shortened dental arch affects human brain activity in the middle frontal gyrus during gum chewing, and the decreased middle frontal gyrus activation may be associated with decreased masticatory function. © 2014 John Wiley & Sons Ltd.

  15. Implant-supported mandibular removable partial dentures: Functional, clinical and radiographical parameters in relation to implant position.

    PubMed

    Jensen, Charlotte; Speksnijder, Caroline M; Raghoebar, Gerry M; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S

    2017-06-01

    Patients with a Kennedy class I situation often encounter problems with their removable partial denture (RPD). To assess the functional benefits of implant support to RPDs, the clinical performance of the implants and teeth and to determine the most favorable implant position: the premolar (PM) or molar (M) region. Thirty subjects received 2 PM and 2 M implants. A new RPD was made. Implant support was provided 3 months later. In a cross-over model, randomly, 2 implants (PM or M) supported the RPD during 3 months. Masticatory performance was assessed using the mixing ability index (MAI). Clinical and radiographic parameters were assessed. Non-parametric statistical analysis for related samples and post hoc comparisons were performed. Masticatory performance differed significantly between the stages of treatment (P < .001). MAI-scores improved with implant support although the implant position had no significant effect. No complications to the implants or RPD were observed and clinical and radiographical parameters for both implants and teeth were favorable. Higher scores for bleeding on probing were seen for molar implants. Implant support to a Kennedy class I RPD significantly improves masticatory function, regardless of implant position. No major clinical problems were observed. © 2017 Wiley Periodicals, Inc.

  16. Preliminary Clinical Application of Removable Partial Denture Frameworks Fabricated Using Computer-Aided Design and Rapid Prototyping Techniques.

    PubMed

    Ye, Hongqiang; Ning, Jing; Li, Man; Niu, Li; Yang, Jian; Sun, Yuchun; Zhou, Yongsheng

    The aim of this study was to explore the application of computer-aided design and rapid prototyping (CAD/RP) for removable partial denture (RPD) frameworks and evaluate the fitness of the technique for clinical application. Three-dimensional (3D) images of dentition defects were obtained using a lab scanner. The RPD frameworks were designed using commercial dental software and manufactured using selective laser melting (SLM). A total of 15 cases of RPD prostheses were selected, wherein each patient received two types of RPD frameworks, prepared by CAD/RP and investment casting. Primary evaluation of the CAD/RP framework was performed by visual inspection. The gap between the occlusal rest and the relevant rest seat was then replaced using silicone, and the specimens were observed and measured. Paired t test was used to compare the average thickness and distributed thickness between the CAD/RP and investment casting frameworks. Analysis of variance test was used to compare the difference in thickness among different zones. The RPD framework was designed and directly manufactured using the SLM technique. CAD/RP frameworks may meet the clinical requirements with satisfactory retention and stability and no undesired rotation. Although the average gap between the occlusal rest and the corresponding rest seat of the CAD/RP frameworks was slightly larger than that of the investment casting frameworks (P < .05), it was acceptable for clinical application. RPD frameworks can be designed and fabricated directly using digital techniques with acceptable results in clinical application.

  17. Oral conditions and aptitude to receive implants in patients with removable partial denture: a cross-sectional study. Part II Aptitude.

    PubMed

    Bassi, F; Schierano, G; Lorenzetti, M; Preti, G

    1996-03-01

    The aim of this study was to evaluate the possibility of replacing removable partial denture (RPD) with fixed partial dentures on osseointegrated implants in a selective group of patients with partially edentulous lower jaws. Forty patients were evaluated to receive implants. Twenty-three patients showed a precarious oral hygiene, five patients refused the treatment (being satisfied with their RPD), six refused for economic reasons, three patients refused for fear and scepticism, one for long duration of therapy, and one was not treated because of a very marked atrophy of the alveolar crest. Finally, one patient was treated with implants. For these reasons, at the present time implants are not an appropriate treatment for introduction into large-scale public health programmes and RPD must still be considered a valid therapeutic procedure.

  18. Comparison of the in vitro fatigue resistance of an acrylic resin removable partial denture reinforced with continuous glass fibers or metal wires.

    PubMed

    Vallittu, P K

    1996-06-01

    The fatigue resistance of heat-polymerized acrylic resin test specimens reinforced with continuous glass fibers or metal wire was investigated. Test specimens in the shape of maxillary removable partial dentures were reinforced with one of the following: (1) circular steel wire (cross-sectional diameter, 1.0 mm); (2) semicircular steel wire (cross-sectional diameter, 1.0 x 2.0 mm); or (3) continuous unidirectional E-glass fibers. Ten specimens were fabricated for each test group. The specimens were tested by a constant force flexural fatigue test at a force of 180 N while immersed in 37 degrees C water. The number of loading cycles required to generate a fatigue fracture and the position of the fracture were measured. Results showed that the test specimens, which were either unreinforced or reinforced with metal wires, fractured after 13,197 to 39,237 loading cycles. For the glass fiber-reinforced test specimens, the fracture did not coincide with the region of the strengthener but with the opposite side of the test specimen after 1,239,298 loading cycles. The position of the fracture showed a statistically significant variation between the test groups (P < .001). This study suggests that the fatigue resistance of acrylic resin removable partial dentures reinforced with glass fibers are superior to those removable partial dentures reinforced with conventional metal wire.

  19. The effect of four sprue shapes on the quality of cobalt-chromium cast removable partial denture frame-works

    PubMed Central

    Viswambaran, M.; Agarwal, S. K.

    2013-01-01

    Statement of Problem: Sprue design is a factor that controls the velocity and adequate supply of metal to the mould. Currently various manufacturers recommend different shapes of sprue, which have not been advocated in textbooks and literature is lacking for their routine applications. Purpose: This in vitro study was carried out to determine the efficacy of four sprue shapes in producing complete, void free cobalt-chrome removable partial denture frameworks. Materials and Methods: A brass metal die with a Kennedy class III, modification 1, partially edentulous arch was used and four sprue shapes (Group A-Ribbon, Group B-Square, Group C-Round and Group D- Round with reservoir) were evaluated. 40 refractory casts were made, 10 wax patterns for each sprue design were waxed up, invested with phosphate bonded investment material and castings done with induction casting machine by the same operator under standardized protocols. The cast frameworks were evaluated for 1. The defects observed visually before finishing and polishing procedures, 2. Fit on the master die as seen with naked eye and 3. Defects on radiographic evaluation. Data were tabulated and statistically analyzed with 1-way ANOVA followed by Student ‘t’ test. Results: The results differed significantly (P < 0.0001) between the Groups with maximum defects in the castings of Group A followed in decreasing order by Group B, Group C and Group D. When comparing between the Groups (P < 0.05), the defects in Groups C and D was significantly lower than Group A and Group B. Conclusions: Round sprues with reservoir produced most satisfactory fit of castings with minimum number of internal and external defects. PMID:24014998

  20. The path of placement of a removable partial denture: a microscope based approach to survey and design.

    PubMed

    Mamoun, John Sami

    2015-02-01

    This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth.

  1. The path of placement of a removable partial denture: a microscope based approach to survey and design

    PubMed Central

    2015-01-01

    This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth. PMID:25722842

  2. The use of a rotational-path design for a mandibular removable partial denture.

    PubMed

    Garcia, Lily T; Bohnenkamp, David M

    2004-07-01

    The lack of display of anterior metal clasps is a primary advantage of the A-P rotational-path mandibular RPD design. A disadvantage of this design is that it relies on rigidmetal guiding plates for anterior retention and stability. Loss of retention may require procedures much more involved than the simple adjustment of conventional RPD clasps. Proper adherence to design, survey, fabrication, and adjustment procedures described by the authors should result in an esthetically pleasing and well-retained tooth-supported removable prosthesis. This article recommends the A-P rotational-path mandibular RPD as a treatment the clinician can use to restore multiple missing anterior teeth and satisfy a patient's financial, esthetic, and functional requirements.

  3. Comparison of functionally orientated tooth replacement and removable partial dentures on the nutritional status of partially dentate older patients: a randomised controlled clinical trial.

    PubMed

    McKenna, Gerald; Allen, P Finbarr; O'Mahony, Denis; Flynn, Albert; Cronin, Michael; DaMata, Cristiane; Woods, Noel

    2014-06-01

    The aims of this study were to conduct a randomised controlled clinical trial (RCT) of partially dentate older adults comparing functionally orientated treatment based on the SDA concept with conventional treatment using RPDs to replace missing natural teeth. The two treatment strategies were evaluated according to their impact on nutritional status measured using haematological biomarkers. A randomised controlled clinical trial (RCT) was conducted of partially dentate patients aged 65 years and older (Trial Registration no. ISRCTN26302774). Each patient provided haematological samples which were screened for biochemical markers of nutritional status. Each sample was tested in Cork University Hospital for serum Albumin, serum Cholesterol, Ferritin, Folate, Vitamin B12 and 25-hydroxycholecalciferol (Vitamin D). A mixed model analysis of covariance (ANCOVA) indicated that for Vitamin B12 (p=0.9392), serum Folate (p=0.5827), Ferritin (p=0.6964), Albumin (p=0.8179), Serum Total Cholesterol (p=0.3670) and Vitamin D (p=0.7666) there were no statistically significant differences recorded between the two treatment groups. According to the mixed model analysis of covariance (ANCOVA) for Vitamin D there was a significant difference between levels recorded at post-operative time points after treatment intervention (p=0.0470). There was an increase of 7% in 25-hydroxycholecalciferol levels recorded at 6 months compared to baseline (p=0.0172). There was no further change in recorded levels at 12 months (p=0.6482) and these increases were similar within the two treatment groups (p>0.05). The only measure which illustrated consistent significant improvements in nutritional status for either group were Vitamin D levels. However no significant difference was recorded between the two treatment groups. Functionally orientated prosthodontic rehabilitation for partially dentate older patients was no worse than conventional removable partial dentures in terms of impact on nutritional

  4. Effect of storage time and framework design on the accuracy of maxillary cobalt-chromium cast removable partial dentures

    PubMed Central

    Viswambaran, M.; Sundaram, R. K.

    2015-01-01

    Statement of Problem: Inaccuracies in the fit of palatal major connectors may be related to distortion of the wax pattern due to prolonged storage time and faulty major connector design. Purpose: This in vitro study was carried out to find out the effect of storage time and major connector design on the accuracy of cobalt-chromium cast removable partial dentures (RPDs). Materials and Methods: A brass metal die with a Kennedy Class III, modification 1, the partially edentulous arch was used as a master die. Thirty-six refractory casts were fabricated from the master die. The refractory casts were divided into three groups (Group I: Anterior-posterior palatal bar, Group II: Palatal strap and Group III: Palatal plate) based on the design of maxillary major connector and subdivided into four groups (sub Group A: 01 h, sub Group B: 03 h, Sub Group C: 06 h, and sub Group D: 24 h) based on the storage time. For each group, 12 frameworks were fabricated. The influence of wax pattern storage time and the accuracy of the fit palatal major connector designs on the master die were compared. Casting defects (nodules/incompleteness) of the frameworks were also evaluated before finishing and polishing. Repeated measures analysis of variance was used to analyze the data. Results: The gap discrepancy was least in sub Group A (01 h) followed by sub Group B (03 h) and C (06 h) and most in sub Group D (24 h). Statistically significant differences (P < 0.05 in all locations L1–L5) in the fit of the framework were related to the design of the major connector. The gap discrepancy was least in Group I (anterior-posterior palatal bar) followed by Group II (palatal strap) and most in Group II (palatal plate). Conclusions: It is recommended that the wax patterns for RPD to be invested immediately on completion of the wax procedure. The selection of a major connector design is crucial for an accurate fit of RPD. PMID:26681850

  5. [Oral mucosa reaction in patients adapting to removable dentures].

    PubMed

    Iordanishvili, A K; Soldatova, L N; Pikhur, O L; Mikhailova, E S; Peremyshlenko, A S; Soldatov, V S

    2016-01-01

    Oral mucosa reaction of prosthetic bed to the removable acrylic dentures was evaluated in 43 patients (12 male and 31 female) aged 56-69 years with partial and full teeth loss in one or both jaws. Patients of the first (control) group (17 patients) were not using additional tools improving fixation of the removable dentures during adaptation period, while patients of the second (main) group (26 patients) used Corega cream for dentures fixation for 30 days follow-up. Oral mucosa assessment was carried out on 3-4 and 28-30 day of dentures use by 3 end points: pain syndrome, moisture level, inflammation of a prosthetic bed. The results proved Corega cream to improve prosthetic bed mucosa condition reducing inflammatory response to polymeric materials of removable dentures basis.

  6. Telescopic Partial Dentures-Concealed Technology

    PubMed Central

    Bhagat, Tushar Vitthalrao; Walke, Ashwini Nareshchandra

    2015-01-01

    The ideal goal of good dentist is to restore the missing part of oral structure, phonetics, his look and the most important is restored the normal health of the patient, which is hampered due to less or insufficient intake of food. Removable partial denture (RPD) treatment option is considered as a notion, which precludes the inevitability of “floating plastic” in edentulous mouth, that many times fail to fulfill the above essential of the patients. In modern dentistry, though the dental implants or fixed partial denture is the better options, but they have certain limitations. However, overdentures and particularly telescopic denture is the overlooked technology in dentistry that would be a boon for such needy patients. Telescopic denture is especially indicated in the distal edentulous area with minimum two teeth bilaterally present with a good amount of periodontal support. This treatment modality is sort of preventive prosthodontics remedy, which in a conservative manner preserve the remaining teeth and helps in conservation of alveolar bone ultimately. There are two tenets related to this option, one is constant conservation edentulous ridge around the retained tooth and the most important is the endless existence of periodontal sensory action that directs and monitor gnathodynamic task. In this option the primary coping or inner coping are cemented on the prepared tooth, and a similar removable outer or inner telescopic crown placed tightly by using a mechanism of tenso-friction, this is firmly attached to a removable RPD in place without moving or rocking of the prosthesis, which is the common compliant of almost all patients of RPD. Copings are also protecting the abutment from tooth decay and also offers stabilization and maintaining of the outer crown. The outer crown engages the inner coping and gives as an anchor for the remainder of the dentition. This work is the review of telescopic prosthesis which is well supported by the case discussion, and

  7. Extensive fixed partial dentures on mandibular canine teeth: a 5-year recall study.

    PubMed

    Carlson, B R; Yontchev, E; Carlsson, G E

    1989-01-01

    Twelve patients were followed for 5 years after treatment with a 12-unit cantilever fixed partial denture on the mandibular canines opposed by a complete maxillary denture. Two fixed dentures had to be removed, one because of an abutment tooth root-fracture and one because of rapid marginal bone loss in a terminal stage of leukemia. Caries and periodontal lesions were rare, but other complications, principally related to endodontics, occurred. All complications were amenable to standard treatment procedures. Extensive mandibular cantilever fixed partial dentures may be used in the rehabilitation of patients with a very reduced dentition and a history of difficulties in adapting to removable dentures.

  8. Quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures in general dental practice in England, Ireland and Wales in 2009.

    PubMed

    Kilfeather, G P; Lynch, C D; Sloan, A J; Youngson, C C

    2010-04-01

    The aim of this study was to investigate the quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures (RPDs) in general dental practice in England, Ireland and Wales in 2009. Two hundred and ten questionnaires were distributed to 21 laboratories throughout England, Ireland and Wales. Information was collected regarding the quality of written communication and selection of master impression techniques for cobalt chromium partial dentures in general dental practice. One hundred and forty-four questionnaires were returned (response rate = 68%). Alginate was the most popular impression material being used in 58% of cases (n = 84), while plastic stock trays were the most popular impression tray, being used in 31% of cases (n = 44). Twenty-four per cent (n = 35) of impressions were not adequately disinfected. Opposing casts were provided in 81% of cases (n = 116). Written instructions were described as being 'clear' in 31% of cases (n = 44). In 54% of cases (n = 76), the technician was asked to design the RPD. Based on the findings of this study, written communication for cobalt chromium RPDs by general dental practitioners is inadequate. This finding is in breach of relevant contemporary legal and ethical guidance. There are also concerns in relation to the fabrication process for this form of prosthesis, particularly, in relation to consideration of occlusal schemes.

  9. The masticatory handicap of wearing removable dentures in elderly men.

    PubMed

    Liedberg, Birgitta; Stoltze, Kaj; Owall, Bengt

    2005-03-01

    This study aimed at describing the masticatory handicap of wearing removable dentures measured by some masticatory tests and the intake of hard and soft foods. The subjects were participants in a comprehensive health examination of 67-68-year-old men living in Malmö, Sweden. Four hundred eighty-three men took part in a clinical oral examination which recorded the number of teeth and removable dentures. One hundred and one had complete dentures in both jaws and 131 had removable partial dentures in different combinations. Masticatory tests used almonds to record the number of stokes to the first swallow, and two-coloured chewing gums for recording bolus kneading and shaping. A nutritionist paid a home visit to assess dietary habits including the consumption of hard and soft foods. The data could be split into groups of different tooth and denture situations which were large enough to enable statistical analysis to be carried out. The results of a regression analysis of the group with different numbers of natural teeth (NT) and no removable dentures could be used as a reference for correlation with the masticatory capacity of removable denture wearers. Number of strokes to the first swallow revealed no masticatory limitations of wearing removable dentures, while chewing gum colour-mixing and shaping revealed more differentiated impairments equivalent to the function of five to 16 teeth in a remaining natural dentition. Hard food intake for the removable denture groups was comparable to 17-19 NT. Soft food intake was not influenced by denture wearing. In a ranking of oral conditions, those with more than 24 NT had the highest test values for all tests, and those with complete sets of dentures the lowest except for the number of strokes to the first swallow of an almond. Removable denture wearing can be regarded as a handicap when measured with objective masticatory tests using chewing gum and the intake of hard foods. The number of chewing strokes to the first

  10. Quality of Life with Removable Dentures

    PubMed Central

    Hadzipasic-Nazdrajic, Amra

    2011-01-01

    Goal: To measure change in a quality of life after treatment with removable dentures and to describe differences in quality of life in patients with new and worn out dentures. Materials and methods: Measuring instrument was OHIP-49, translated from English into one of the languages in Bosnia-Herzegovina. Sample consisted of patients who wanted to make/replace mobile dentures or came to repair a broken dentures. Comprehensibility of the OHIP-BH49 was tested on a sub-sample of patients. Three measurements were made: before and after the insertion of dentu res and when patients came to repair their mobile dentures. Results: Sample consisted of 67 patients: 32 patients who sought prosthetic treatment, and 35 who came to repair their broken dentures. We received 89.7% correctly filled questionnaires. Minor changes were made in four (4) questions. Statistical analysis performed with the T-test revealed the significant differences, before and after the treatment with mobile dentures (t=39.5, p<0.001). There was a significant difference in OHIP scores in patients with a new dentures, compared to the patients who had worn out dentures (t=44.30, p<0.001). Substantial differences, between OHIP scores, regarding the time of wearing dentures or patients’ age were not observed. Discussion: Patients who wore dentures longer than 5 years, showed better quality of life, because they became accustomed to the dentures. Conclusions: Self-reported life quality improved considerably after insertion of a new dentures. Patients with a new dentures showed significantly better quality of life than patients with worn out dentures. One part of OHIP validation in Bosnia-Herzegovina has been done. PMID:23678299

  11. A structural equation model relating objective and subjective masticatory function and oral health-related quality of life in patients with removable partial dentures.

    PubMed

    Fueki, K; Yoshida, E; Igarashi, Y

    2011-02-01

    The aim of this study was to investigate the relationships between objective masticatory function with respect to masticatory performance and food mixing ability, patients' perception of chewing ability and oral health-related quality of life (OHRQoL). Partially dentate patients with removable partial dentures (n = 131, mean age 67·1 year) participated in the study. Four tests were performed to evaluate objective and subjective masticatory function and OHRQoL. Masticatory performance and food mixing ability were assessed using peanuts or a two-coloured wax cube as test items. Patients' perception of chewing ability was rated using a food intake questionnaire. OHRQoL was measured using the Japanese version of the oral health impact profile. A structural equation model was constructed based on hypothesis in which objective masticatory function would be related to OHRQoL via perceived chewing ability as a mediator. Structural equation modelling analysis found a statistically significant medium effect of perceived chewing ability on OHRQoL and statistically significant medium or small effects of masticatory performance on perceived chewing ability and OHRQoL (P < 0·05); however, the effect of food mixing ability on perceived chewing ability or OHRQoL was not statistically significant (P > 0·05). A fit index indicated that the model fitted well to the data (Goodness-of-fit index = 0·99). These results suggest that perceived chewing ability is a critical factor for OHRQoL and that masticatory performance rather than food mixing ability is important for perceived chewing ability and OHRQoL in patients with removable partial dentures.

  12. Clinical application of removable partial dentures using thermoplastic resin. Part II: Material properties and clinical features of non-metal clasp dentures.

    PubMed

    Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

    2014-04-01

    This position paper reviews physical and mechanical properties of thermoplastic resin used for non-metal clasp dentures, and describes feature of each thermoplastic resin in clinical application of non-metal clasp dentures and complications based on clinical experience of expert panels. Since products of thermoplastic resin have great variability in physical and mechanical properties, clinicians should utilize them with careful consideration of the specific properties of each product. In general, thermoplastic resin has lower color-stability and higher risk for fracture than polymethyl methacrylate. Additionally, the surface of thermoplastic resin becomes roughened more easily than polymethyl methacrylate. Studies related to material properties of thermoplastic resin, treatment efficacy and follow-up are insufficient to provide definitive conclusions at this time. Therefore, this position paper should be revised based on future studies and a clinical guideline should be provided. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  13. The Effects of Removable Denture on Swallowing

    PubMed Central

    Son, Dae-Sik; Seong, Jin Wan; Kim, Younghoon; Chee, Youngjoon

    2013-01-01

    Objective To investigate the relationship between removable dentures and swallowing and describe risks. Methods Twenty-four patients with removable dentures who were referred for videofluoroscopic swallowing study (VFSS) were enrolled. We evaluated the change of swallowing function using VFSS before and after the removal of the removable denture. The masticatory performance by Kazunori's method, sensation of oral cavity by Christian's method, underlying disease, and National Institutes of Health Stroke Scale for level of consciousness were collected. Functional dysphagia scales, including the oral transit time (OTT), pharyngeal transit time (PTT), percentage of oral residue, percentage of pharyngeal residue, oropharyngeal swallow efficiency (OPSE), and presence of aspiration were measured. Results Four patients dropped out and 20 patients were analyzed (stroke, 13 patients; pneumonia, 3 patients; and others, 4 patients). The mean age was 73.3±11.4 years. There were significant differences before and after the removal of the denture for the OTT. OTT was significantly less after the removal of the denture (8.87 vs. 4.38 seconds, p=0.01). OPSE increased remarkably after the removal of the denture, but without significance (18.24%/sec vs. 25.26%/sec, p=0.05). The OTT and OPSE, while donning a removable denture, were correlated with the masticatory performance (OTT, p=0.04; OPSE, p=0.003) and sensation of oral cavity (OTT, p=0.006; OPSE, p=0.007). Conclusion A removable denture may have negative effects on swallowing, especially OTT and OPSE. These affects may be caused by impaired sensation of the oral cavity or masticatory performance induced by the removable denture. PMID:23705121

  14. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a... mold, by partially polymerizing the resin denture base materials while the materials are in contact...

  15. A Survey of Removable Partial Denture (RPD) Retentive Elements in Relation to the Type of Edentulism and Abutment Teeth Found in Commercial Laboratories, Athens, Greece.

    PubMed

    Polychronakis, Nick; Sotiriou, Michael; Zissis, Alcibiades

    2014-09-01

    The aim of this survey was to record removable partial denture (RPD) retentive elements and abutment teeth in partially edentulous patients, identified in commercial laboratories in Athens, Greece. 628 master casts with the corresponding cast metal frameworks used in the construction of RPDs were evaluated. Casts were photographed to identify the number and position of existing teeth, the partial edentulism class and the retentive elements. Prevalence tables and the x(2) test were used for the statistical analysis of the collected data (α=.05). There were 276 maxillary (43.9%) and 352 (56.1%) mandibular casts. Maxillary edentulism entailed almost a total absence of right third molars in 96.7% and left third molars 96.0% of casts, with lower rates for the first and second molars. Edentulism in the posterior mandible presented a similar pattern. The most profound findings concerning retentive elements were: 91.9% of the retainers used were clasps and the remaining 8.1% were attachments. Of the clasps used, 48.9% were of the Roach Τ type, a finding more common in Kennedy Class I as compared to other Kennedy Classes (p<0.01). The circumferential clasps accounted for 19.3% of the total clasps used, and it was less frequently presented (8.8%) in Kennedy I Classes (p<0.01). Roach clasps were used in the majority of cases whereas RPI clasps and attachments were rarely used.

  16. Denture quality has a minimal effect on health-related quality of life in patients with removable dentures.

    PubMed

    Inoue, M; John, M T; Tsukasaki, H; Furuyama, C; Baba, K

    2011-11-01

    The present study examined the association of denture quality and health-related quality of life (HRQoL) in patients with removable dentures. In a study of 171 consecutive patients with removable partial dentures or complete dentures (mean age: 68·0 ± 9·3 years) at a university-based prosthodontic clinic, dentists rated two aspects of denture quality (stability and aesthetics) using a 100-mm visual analog scale (VAS). HRQoL was evaluated using the mental and physical component summary (MCS and PCS) scores of the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36). Oral health-related quality of life (OHRQoL) was evaluated using the Oral Health Impact Profile-Japanese version (OHIP-J). The associations among denture quality, OHRQoL, and HRQoL were examined by linear regression models. Bivariable linear regression analyses revealed that denture stability was significantly associated with the SF-36 MCS [regression coefficient = 0·52 for a 10-unit increase in denture stability on a 0-100 VAS, 95% confidence interval (CI): 0·03-1·00, P = 0·04], but not with the PCS (0·11, 95% CI: -0·49 to 0·70). Denture aesthetics was not related to the PCS or the MCS (0·22, 95% CI: -0·44 to 0·88 or 0·07, 95%CI: -0·47 to 0·62). When OHIP-J was added to the regression model, this variable was substantially and significantly associated with the MCS and PCS summary scores; in addition, the regression coefficient for denture quality decreased in magnitude and was statistically nonsignificant in all analyses. The quality of removable dentures had a minimal effect on HRQoL in patients with removable dentures, and this association was mediated by OHRQoL. © 2011 Blackwell Publishing Ltd.

  17. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is... with the oral tissues. After the denture base is constructed, the connected preformed teeth...

  18. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is... with the oral tissues. After the denture base is constructed, the connected preformed teeth...

  19. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is... with the oral tissues. After the denture base is constructed, the connected preformed teeth...

  20. Transesophageal echocardiogram causing denture dislodgement with upper airway partial obstruction.

    PubMed

    Ahmed, Najeeb; Shaikh, Azim

    2009-06-01

    A 30-year-old female was evaluated with transesophageal echocardiography to exclude an atrial septal defect. The patient denied having dentures or partial dentures during her pre-procedure history and immediately prior to the procedure. Following the transesophageal echocardiography it was discovered that the patient had a partial airway obstruction caused by dislodgement of her partial dentures. The case illustrates the importance of not only asking patients if they have dentures, partial dentures, or any dental appliances, but also manually checking and directly looking into patients' mouths prior to transesophageal echocardiography for any dental appliances.

  1. A Treatment Protocol for Restoring Occlusal Vertical Dimension Using an Overlay Removable Partial Denture as an Alternative to Extensive Fixed Restorations: A Clinical Report

    PubMed Central

    Patel, Mit B; Bencharit, Sompop

    2009-01-01

    Treatment options for patients with severe attrition resulting in reduced occlusal vertical dimension are often limited to fixed prosthesis to reestablish proper occlusal vertical dimension and functional occlusion. In some cases such as when there are limited finances, minimal esthetic concerns, and medical considerations fixed prosthesis may not be the ideal treatment option. Overlay removable partial dentures (ORPDs) can be used as a provisional or interim prosthesis as well as permanent prosthesis in these cases. While ORPDs can provide a reversible and relatively inexpensive treatment for patients with a significantly compromised dental status, there is not much scientific evidence in the literature on ORPDs. Most studies published on ORPDs to date are primarily reviews and clinical reports. In this article, literatures on ORPDs are summarized and a patient treated with interim and permanent ORPDs is presented. This article reviews previously published literatures on the use of ORPDs. Indications, advantages and disadvantages are discussed. Treatment protocol with an example of the prosthodontic treatment of a patient with severely worn dentition with an interim ORPD and later a permanent ORPD are discussed in details. PMID:19915723

  2. Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using contact elements and micro-CT data.

    PubMed

    Rocha, Eduardo Passos; Anchieta, Rodolfo Bruniera; de Almeida, Erika Oliveira; Freitas, Amilcar Chagas; Martini, Ana Paula; Sotto-Maior, Bruno Sales; Luersen, Marco Antonio; Ko, Ching Chang

    2015-01-01

    Veneer fracture is the most common complication in zirconia-based restorations. The aim of this study was to evaluate the mechanical behavior of a zirconia-based crown in a lower canine tooth supporting removable partial denture (RPD) prosthesis, varying the bond quality of the veneer/coping interface. Microtomography (μCT) data of an extracted left lower canine were used to build the finite element model (M) varying the core material (gold core - MAu; zirconia core - MZi) and the quality of the veneer/core interface (complete bonded - MZi; incomplete bonded - MZi-NL). The incomplete bonding condition was only applied for zirconia coping by using contact elements (Target/Contact) with 0.3 frictional coefficients. Stress fields were obtained using Ansys Workbench 10.0. The loading condition (L = 1 N) was vertically applied at the base of the RPD prosthesis metallic support towards the dental apex. Maximum principal (σmax) and von Mises equivalent (σvM) stresses were obtained. The σmax (MPa) for the bonded condition was similar between gold and zirconia cores (MAu, 0.42; MZi, 0.40). The incomplete bonded condition (MZi-NL) raised σmax in the veneer up to 800% (3.23 MPa) in contrast to the bonded condition. The peak of σvM increased up to 270% in the MZi-NL. The incomplete bond condition increasing the stress in the veneer/zirconia interface.

  3. Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

    PubMed

    Cortes, Arthur Rodriguez Gonzalez; Cortes, Djalma Nogueira; No-Cortes, Juliana; Arita, Emiko Saito

    2014-06-01

    The present retrospective case series is aimed at evaluating a staged approach using a removable partial denture (RPD) as an interim prosthesis in treatment to correct a failing dentition until such time as a full-arch fixed implant-supported prosthesis may be inserted. Eight patients, who had undergone maxillary full-arch rehabilitation with dental implants due to poor prognosis of their dentitions, were analyzed. All treatment included initial periodontal therapy and a strategic order of extraction of hopeless teeth. An RPD supported by selected teeth rehabilitated the compromised arch during implant osseointegration. These remaining teeth were extracted prior to definitive prosthesis delivery. Advantages and drawbacks of this technique were also recorded for the cases presented. Among the advantages provided by the staged approach are simplicity of fabrication, low cost, and ease of insertion. Additionally, RPD tooth support prevented contact between the interim prosthesis and healing abutments, promoting implant osseointegration. The main drawbacks were interference with speech and limited esthetic results. Implant survival rate was 100% within a follow-up of at least 1 year. The use of RPDs as interim prostheses allowed for the accomplishment of the analyzed rehabilitation treatments. It is a simple treatment alternative for patients with a low smile line. © 2013 by the American College of Prosthodontists.

  4. Use of intraoral scanning and 3-dimensional printing in the fabrication of a removable partial denture for a patient with limited mouth opening.

    PubMed

    Wu, Jiang; Li, Yan; Zhang, Yumei

    2017-05-01

    When treating patients with severely limited mouth openings, it is difficult for the dentist to obtain an impression and fabricate a removable partial denture (RPD) by using traditional methods. Intraoral scanning, computer-aided design, and 3-dimensional (3D) printing have provided alternative methods for fabricating dental prostheses. The authors present a case in which they aimed to improve the efficiency and quality of fabricating an RPD framework by integrating the technologies of intraoral scanning, computer-aided design, and 3D printing. Initially, the authors reconstructed the digital cast with multiple intraoral scans. Subsequently, the authors designed the virtual RPD framework. On the basis of the virtual framework, the titanium alloy framework was fabricated by means of a 3D printing process, and the authors fitted the final RPD to the patient. Unlike the traditional method, this integrated system has the potential to design a custom-made dental prosthesis and directly make an RPD framework with complicated patterns. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

  5. Clinical survey of acrylic resin removable denture repairs with glass-fiber reinforcement.

    PubMed

    Narva, K K; Vallittu, P K; Helenius, H; Yli-Urpo, A

    2001-01-01

    The aim of this study was to evaluate clinical usefulness and durability of continuous glass-fiber reinforcement in repair of acrylic resin removable dentures. Fractured removable dentures without reinforcement, with conventional metal-wire reinforcement, or with mesh reinforcement were collected from two dental schools in Finland. The total number of dentures was 51 and the number of patients was 48. During the repair, the dentures were reinforced with a polymer-preimpregnated E-glass fiber at the region of the fracture. The fibers were used as partial fiber reinforcement, i.e., only the weakest part of the denture was reinforced. Follow-up time varied from 4 months to 4.1 years. After the follow-up period, possible fractures and discoloring were visually inspected. Possible irritation of oral mucosa by glass fibers and the general shape of the denture were also evaluated. In 88% of the cases, there was no need for adjustment at the region of partial fiber reinforcement, and the clinical condition of the dentures was good. Glass fibers did not irritate the oral mucosa. In the case of refracture or hairline fracture, positioning of the partial fiber reinforcement was incorrect or the reinforcement had been used incorrectly (the wetting of the reinforcement with denture base resin was inadequate). Polymer-preimpregnated partial fiber reinforcement seems to be useful in eliminating fractures of acrylic resin removable dentures. However, this study emphasizes the importance of correct positioning and accurate laboratory technique when partial fiber reinforcement is used.

  6. The role of friction in the mechanism of retaining the partial removable dentures with double crown system.

    PubMed

    Dąbrowa, Tomasz; Dobrowolska, Anna; Wieleba, Wojciech

    2013-01-01

    Cylindrical telescopic crowns belong to bolt dentures, because their adhesion strength is based on the friction force. The magnitude of static and slide friction forces depends on the strain within the contact area and properties of materials employed. Friction force value between telescope elements declines in the first phase of wearing period and, subsequently, maintains particular constant value of 8 to 10 N. In the telescopic technique, homo and heterogenic joints are used. The following prosthodontic materials have been examined: goldbase alloys (Degudent Kiss, Degulor M), cobalt-base alloy (Brealloy 270), ceramics (Zircon Oxide, Zirconia) during tribological investigations on FGP composite resin. The cooperating surfaces were moistened with synthetic saliva. The research confirmed the dependence of the static friction coefficient on the contact pressure for the analyzed pairs of materials used in prosthodontics. The biggest effect of the contact pressure on the coefficient of friction value occurs when the ceramic rubs on FGP composite resin. The most stable friction coefficient in the context of contact pressure changes as well as life has been found in the case of the cobalt alloy Brealloy 270. An interesting material is a gold alloy Degulor M, for which the coefficient of friction varies only slightly with pressure in the range of 0.6 to 0.9 MPa.

  7. Effects of Length and Inclination of Implants on Terminal Abutment Teeth and Implants in Mandibular CL1 Removable Partial Denture Assessed by Three-Dimensional Finite Element Analysis

    PubMed Central

    Fayaz, Amir; Geramy, Alahyar; Memari, Yeganeh

    2015-01-01

    Objectives: This study sought to assess the effects of length and inclination of implants on stress distribution in an implant and terminal abutment teeth in an implant assisted-removable partial denture (RPD) using three-dimensional (3D) finite element analysis (FEA). Materials and Methods: In this in vitro study, a 3D finite element model of a partially dentate mandible with a distal extension RPD (DERPD) and dental implants was designed to analyze stress distribution in bone around terminal abutment teeth (first premolar) and implants with different lengths (7 and 10 mm) and angles (0°, 10° and 15°). Results: Stress in the periodontal ligament (PDL) of the first premolar teeth ranged between 0.133 MPa in 10mm implants with 15° angle and 0.248 MPa in 7mm implants with 0° angle. The minimum stress was noted in implants with 10mm length with 0° angle (19.33 MPa) while maximum stress (25.78 MPa) was found in implants with 10mm length and 15° angle. In implants with 7 mm length, with an increase in implant angle, the stress on implants gradually increased. In implants with 10 mm length, increasing the implant angle gradually increased the stress on implants. Conclusion: Not only the length of implant but also the angle of implantation are important to minimize stress on implants. The results showed that vertical implant placement results in lower stress on implants and by increasing the angle, distribution of stress gradually increases. PMID:27252757

  8. Distortion of ceramometal fixed partial dentures during the firing cycle.

    PubMed

    Bridger, D V; Nicholls, J I

    1981-05-01

    1. Distortion does occur in the body of curved, long-span fixed partial denture frameworks during the porcelain firing cycle. 2. This distortion is a result of changes in the metal as well as the contraction of fired porcelain. 3. The greatest distortional changes occur during the degassing stage and the final glaze stage of the porcelain firing cycle. 4. Distortion incurred by the application and firing of the porcelain is reversible. When the porcelain is chemically removed from the framework, there is an elastic rebound. 5. Distortion is clinically important in that it may lead to detectable marginal openings. 6. The distortion pattern observed in the curved fixed partial denture is a closing of the posterior or lingual dimensions and labial movement in the anterior dimension. This indicates the effect of the contracting porcelain on the metal framework.

  9. 21 CFR 872.3600 - Partially fabricated denture kit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Partially fabricated denture kit. 872.3600 Section 872.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... mold, by partially polymerizing the resin denture base materials while the materials are in...

  10. The effect of various factors on the masticatory performance of removable denture wearer

    NASA Astrophysics Data System (ADS)

    Pratama, S.; Koesmaningati, H.; Kusdhany, L. S.

    2017-08-01

    An individual’s masticatory performance concerns his/her ability to break down food in order to facilitate digestion, and it therefore plays an important role in nutrition. Removable dentures are used to rehabilitate a loss of teeth, which could jeopardize masticatory performance. Further, there exist various other factors that can affect masticatory performance. The objective of this research is to analyze the relationship between various factors and masticatory performance. Thirty-four removable denture wearers (full dentures, single complete dentures, or partial dentures) participated in a cross-sectional study of masticatory performance using color-changeable chewing gum (Masticatory Performance Evaluating Gum Xylitol®). The volume of saliva was evaluated using measuring cups, while the residual ridge heights were measured using a modified mouth mirror no. 3 with metric measurements. The residual ridge height and removable-denture-wearing experience exhibited a significant relationship with masticatory performance. However, age, gender, saliva volume, denture type, and the number and location of the missing teeth did not have a statistically significant association with masticatory performance. The residual ridge height influences the masticatory performance of removable denture wearers, since the greater the ridge height, the better the performance. The experience of using dentures also has a statistically significant influence on masticatory performance.

  11. Immediate partial denture with a cast metal framework. A 6-year evaluation.

    PubMed

    Bezzon, O L; de Mattos, M da G; Ribeiro, R F

    1997-01-01

    The use of dentures immediately after tooth removal is a common practice in dentistry especially when tooth extraction causes aesthetic problems. In the field of complete dentures, the procedure for the construction of immediate dentures permits the preparation of prostheses with the characteristics of standard dentures that can be used for a long period of time, promoting the recovery of function and aesthetic appearance without impairing patient comfort. For removable partial dentures, immediate prostheses are usually provisional for use over a short period of time while the extraction site heals. These dentures are usually made with acrylic resin and wrought wires, and in addition to compressing delicate parts of the support system, often do not provide the comfort and security needed by the patient. Immediate removable partial dentures with a metal framework are seldom used for this procedure, probably because of the difficulty in fitting the framework prior to surgery. The authors present a clinical example in which a modification of framework positioning permitted previous fitting of the framework, eliminating the possibility of lack of fit after tooth extraction, which resulted in clinical success 6 years later.

  12. Long-term observations of extensive fixed partial dentures on mandibular canine teeth.

    PubMed

    Carlson, B R; Yontchev, E

    1996-03-01

    Twelve patients were followed for 15 years after treatment with a 12-unit cantilever fixed partial denture on the mandibular canines opposite to a complete maxillary denture. Four constructions failed and had to be removed but four were still in function after 15 years. Four patients died during the observation period still wearing their constructions. Endodontic complications, pulpal necrosis and loss of retention of posts were the most frequent, while caries and periodontal lesions were rare. The maintenance costs over the years were fairly low even compared to maintenance costs for patients treated with implants. Extensive mandibular cantilever fixed partial dentures may be used in the rehabilitation of patients with a very reduced dentition and a history of difficulties adapting to removable dentures.

  13. Removable dentures with eclipse-repairing and relining.

    PubMed

    Bundevska, Jadranka; Panchevska, Sanja; Kovacevska, Gordana

    2014-01-01

    While utilizing removable dentures, regardless of whether the dentures are acrylic or fabricated of eclipse resin, the need for their filling-relining or their repair frequently arises. The purpose of this study is to display the technicalities of the procedure for rebasing and relining of removable light curing eclipse denture resin. This study presents cases of relining and repairing of removable dentures fabricated from light curing ECLIPSE resin on patients at the Department for Removable Prosthodontics at the University Dental Clinic Centre in Skopje. One of the most significant features of this method of fabrication of removable eclipse dentures and their relining and repairing is the shortened duration of work in the dental laboratory. The displayed mode of rebasing also allows us to maintain one of the advantages of this type of dentures--the absence of allergy stomatitis symptoms.

  14. Interim dentures and treatment dentures.

    PubMed

    Smith, D E

    1984-04-01

    Improvement in the interim denture procedure in the past decade has been one of the significant advancements in prosthodontic practice. The interim denture approach is only slightly more time-consuming and expensive than the conventional immediate denture approach, yet it has many advantages. Among those advantages are the following: (1) allows rapid results; (2) results in a higher quality definitive denture; (3) allows the surgical treatment to be performed during one appointment; (4) permits duplication of the natural tooth position; and (5) provides the patient with a spare denture after the definitive denture is completed. An interim denture technique was described that utilized a flexible layered silicone mold to form the replaced teeth. The interim denture procedure is flexible and lends itself to many variations in technique to meet unusual clinical situations. An interim removable partial denture technique was described that involves block-out of undesirable undercuts and duplication of the master cast for fabrication of the partial denture. This technique results in an interim partial denture that can be placed with little or no adjustment and that will provide better service for those who require it. Three simple procedures for fabricating treatment dentures were described and the indications for each were discussed. Although treatment dentures are not often used, they are essential for the dentist who is treating difficult patients who require complete dentures.

  15. Discuss before fabricating: communicating the realities of partial denture therapy. Part II: clinical outcomes.

    PubMed

    Mazurat, Nita M; Mazurat, Randall D

    2003-02-01

    The premise of this review is that patients' satisfaction (and hence compliance) with partial denture therapy may be better if they are more fully informed about the limitations of the prosthesis they are to receive. Neither the dentist nor the patient should assume that all of their respective expectations will be mutually understood and inherently met. By discussing patient-centred issues and predictable clinical outcomes, both dentist and patient will be better prepared to determine whether a removable prosthesis is appropriate. Searches of the Cochrane Collaboration and MEDLINE databases were conducted to identify issues pertaining to patient compliance in wearing cast removable partial dentures. In addition to the 2 most frequent patient concerns, esthetics and mastication, discussed in the first article of this series, additional aspects of concern to the dentist and the patient when considering a removable partial denture include overeruption, post-insertion care, comfort, longevity of the prosthesis, effect on speech and biologic consequences are discussed here.

  16. A modified treatment approach for fabricating a mandibular distal-extension partial denture: a clinical report.

    PubMed

    Prasad, Soni; Monaco, Edward A

    2010-03-01

    An altered cast impression technique is routinely used for fabricating distal-extension partial dentures. The advantages of an altered cast impression technique are that it evenly distributes stresses between hard and soft tissues and reduces stresses to the abutment teeth. However, there is some controversy among clinicians as to the technique and requirements of both tooth and tissue management of the distal-extension partial denture. A modified approach of fabricating a distal-extension partial denture is presented using a laboratory-processed functional reline method. The functional reline is performed after the removable partial denture is processed to perfect the fit of the denture base to the residual ridge. This enables the partial denture to be constructed from a cast made from a single impression and results in a prosthesis that is stable and has well-extended borders. Not only is it easy and less technique-sensitive for the operator, but it also results in increased comfort and reduced need for multiple adjustment visits for the patient.

  17. Capacity of denture plaque/biofilm removal and antimicrobial action of a new denture paste.

    PubMed

    Paranhos, H de F; Panzeri, H; Lara, E H; Candido, R C; Ito, I Y

    2000-01-01

    The efficacy of a paste for complete dentures was analyzed in terms of denture plaque/biofilm removal and antimicrobial action against specific microorganisms by determination of colony forming units of mutans group streptococci and yeast from 120 full denture wearers with a healthy palatine mucosa. The patients were given a questionnaire to evaluate the experimental product in terms of important characteristics. The paste was widely accepted by the patients, and effective in denture plaque removal and antimicrobial action. The species of yeasts most frequently isolated were C. albicans, C. tropicalis and C. glabrata. We conclude that it is possible for complete denture wearers to keep their dentures clean with the regular use of a paste-like hygienic product.

  18. Treatment Outcomes of Cantilever Fixed Partial Dentures on Vital Abutment Teeth: A Retrospective Analysis.

    PubMed

    Rehmann, Peter; Podhorsky, Anke; Wöstmann, Bernd

    2015-01-01

    This retrospective clinical study evaluated the long-term outcomes of cantilever fixed partial dentures (CFPDs) and the factors influencing their survival probability. The study is based on a convenience sample of 57 patients who received 71 CFPDs on a total of 176 vital abutment teeth. The mean survival time of the CFPDs was calculated using a Kaplan-Meier estimate. The following variables were analyzed as covariates of the survival function (logrank test, P < .05): sex, denture location, number and distribution (Kennedy Class) of the abutment teeth, dentition in the opposing arch (removable dentures, fixed partial dentures, or natural dentition), position of the cantilever unit (mesial or distal), and participation in follow-up visits. The mean observation period was 3.2 ± 2.8 years (maximum 10.7 years). During the observation period, 22.5% (n = 16) of the CFPDs ceased functioning. The calculated outcome probability was 93.0% after 5 years and 84.5% after 8 years. The number of abutment teeth was the only parameter that significantly (P < .05) impacted this probability. The survival rate of CFPDs on vital abutment teeth is comparable to that of conventional fixed partial dentures. Thus, CFPDs on vital abutments are an acceptable alternative to removable dentures.

  19. Categorical analysis of factors affecting needs and demands for removable dentures among Alexandria Dental Research Center clientele.

    PubMed

    Zeid, W M; Mohamed, M H; Mahdy, N H; El-Tabakh, S M

    1999-01-01

    An accurate assessment of dental needs is important to public health planners. With this information, it is possible to assess future treatment needs and demands for services including those for removable dentures. The present work aimed to estimate the magnitude and types of needs, and demands for partial or complete removable dentures, to study some factors that may affect the identified needs and demands for removable dentures, in addition to studying the factors that may affect satisfaction with the dentures. The present study was conducted in "Alexandria Dental Research Center". Data were collected by means of interview questionnaire, followed by dental examination of all patients attending the center for the sake of removable dental restorations for a period of 6 months. A further follow up over a period of three months was undertaken to the 330 cases recorded. About one third of the cases demanded partial and/or complete dentures and were above 60 years old. The first purpose for construction of new dentures was mastication, followed by cosmetics. Only one quarter of cases decided to have delayed immediate dentures. Diabetics and those having chronic diseases showed more demand for complete dentures. The most discriminating variable between the demand for different dentures was the missing in the lower anterior teeth followed by missing in the upper both anterior and posterior and then missing in the upper anterior teeth. Satisfaction score increased with advance of age, among males, among those for complete dentures, and those who had had previous dentures. Stepwise logistic regression revealed that the best predictor for overall satisfaction was the history of having previous dentures. Results of the present study, suggest that early screening and treatment of diabetic patients, gathering detailed information by means of a questionnaire before new dentures fabrication may be an important tool for the dentist in predicting and consequently enhancing patient

  20. The fit of fixed partial dentures joined by infrared soldering.

    PubMed

    Byrne, G; Laub, L W; Hu, J Y; Land, M F

    1992-10-01

    This study determined the accuracy of fit of three-unit fixed partial dentures joined by an infrared soldering technique compared with one-piece fixed partial denture castings and individually cast crowns. Wax patterns of prepared Ivorine teeth, maxillary left central incisor and maxillary left canine, were injection molded; a plastic rod was used as a pontic. One group of patterns was cast as one-piece dentures; the other group was sectioned in the connector area, cast individually and then joined by infrared soldering. Castings were seated on their respective dies, embedded in epoxy resin, and sectioned. Gap distances between the casting and the die were measured at specified marginal sites with a profile projector. Results showed that the fit of infrared-soldered fixed partial dentures was significantly better than that of one-piece castings and was comparable with the fit of single crowns. The gap openings measured in all castings were within the range of clinical acceptability.

  1. Endoscopic Removal of Ingested Dentures and Dental Instruments: A Retrospective Analysis

    PubMed Central

    Takahashi, Kazuya; Tominaga, Kentaro; Nishigaki, Yuki; Sato, Hiroki; Ikarashi, Satoshi; Hayashi, Kazunao; Yamamoto, Takashi; Honda, Yutaka; Hashimoto, Satoru; Kamimura, Kenya; Takeuchi, Manabu; Yokoyama, Junji; Sato, Yuichi; Kobayashi, Masaaki; Terai, Shuji

    2016-01-01

    Background. Dentures and dental instruments are frequently encountered ingested foreign bodies. The aim of the present study was to assess the safety and efficacy of endoscopically removing ingested dental objects. Methods. Twenty-nine consecutive patients with 29 dental objects who were treated at the Niigata University Medical and Dental Hospital from August 2009 to December 2015 were retrospectively reviewed. Characteristics of the patients and the ingested dental objects, the clinical features and findings of radiological imaging tests, and outcomes of endoscopic removal were analyzed. Results. Patients' mean age was 62.9 ± 21.0 years. The ingested dental objects included 23 dentures (13 crowns, 4 bridges, 4 partial dentures, and 2 other dentures) and 6 dental instruments. Twenty-seven upper gastrointestinal endoscopies and 2 colonoscopies were performed, and their success rates were 92.6% and 100%, respectively. There were 2 cases of removal failure; one case involved an impacted partial denture in the cervical esophagus, and this case required surgical removal. Conclusions. Endoscopic removal of ingested dentures and dental instruments is associated with a favorable success rate and acceptable complications. The immediate intervention and appropriate selection of devices are essential for managing ingested dental objects. PMID:27738426

  2. Complication rates and patient satisfaction with removable dentures

    PubMed Central

    Bilhan, Hakan; Erdogan, Ozge; Ergin, Selen; Celik, Melahat; Ates, Gokcen

    2012-01-01

    PURPOSE The purpose of this clinical study was to evaluate the frequency and type of prosthetic complications in relation to type and properties of removable dentures and to investigate the influence of these complications and several data about the existing dentures on patient satisfaction. MATERIALS AND METHODS Ninety nine patients (44 males and 55 females) wearing removable dentures have been included in the study. The complications of the patients were recorded; patient satisfaction was determined with a Visual Analog Scale (VAS) and the relationship of complications and patient satisfaction with several data about the dentures such as denture age, type of denture, centric relation and vertical dimension was investigated. Kruskal Wallis, Mann Whitney U and Chi square tests were used for statistical analyses. The results were evaluated statistically at a significance level of P<.05. RESULTS Need for addition of artificial teeth for dentures with correct centric relations was found to be significantly lower than dentures with wrong centric relations (P<.01). Loss of retention, ulcerations and high vertical dimension affected the VAS chewing ability scores negatively and ulcerations affected the VAS phonation scores negatively (P<.05). CONCLUSION Considering the results of this study, it can be concluded that loss of retention, ulcerations and high vertical dimension caused patient dissatisfaction. Additionally, dentures with wrong centric relations caused need for addition of artificial teeth. PMID:22737317

  3. EFFICACY OF THREE DENTURE BRUSHES ON BIOFILM REMOVAL FROM COMPLETE DENTURES

    PubMed Central

    Fernandes, Roseana Aparecida Gomes; Lovato - Silva, Cláudia Helena; Paranhos, Helena de Freitas Oliveira; Ito, Izabel Yoko

    2007-01-01

    The aim of this study was to compare the efficacy of three denture brushes (Bitufo-B; Medic Denture-MD; Colgate-C) on biofilm removal from upper and lower dentures using a specific dentifrice (Corega Brite). The correlation between biofilm levels on the internal and external surfaces of the upper and lower dentures was also evaluated. A microbiological assay was performed to assess the growth of colony-formed units (cfu) of Candida yeasts on denture surface. Thirty-three patients were enrolled in a 10-week trial divided in two stages: 1 (control) – three daily water rinses within 1 week; 2 - three daily brushings within 3 weeks per tested brush. Internal (tissue) and external (right buccal flange) surfaces of the complete dentures were disclosed (neutral red 1%) and photographed. Total denture areas and disclosed biofilm areas were measured using Image Tool 3.00 software for biofilm quantification. Dentures were boxed with #7 wax and culture medium (CHROMagar™ Candida) was poured to reproduce the internal surface. Statistical analysis by Friedman’s test showed significant difference (p<0.01) between control and brushing stages. No difference was found among the brushes with respect to their efficacy on biofilm removal (p>0.01). Analysis by the Correlation test showed higher r values (B=0.78; MD=0.8341, C=0.7362) for the lower dentures comparing the surfaces (internal and external) and higher r values (B=0.7861, MD=0.7955, C=0.8298) for the external surface comparing the dentures (upper and lower). The results of the microbiological showed no significant difference (p>0.01) between the brushes with respect to the frequency of the species of yeasts (chi-square test). In conclusion, all denture brushes evaluated in this study were effective in the removal of biofilm. There was better correlation of biofilm levels between the surfaces for the lower dentures, and between the dentures for the external surface. There was no significant difference among the brushes

  4. Efficacy of three denture brushes on biofilm removal from complete dentures.

    PubMed

    Fermandes, Roseana Aparecida Gomes; Lovato-Silva, Cláudia Helena; Paranhos, Helena de Freitas Oliveira; Ito, Izabel Yoko

    2007-02-01

    The aim of this study was to compare the efficacy of three denture brushes (Bitufo-B; Medic Denture-MD; Colgate-C) on biofilm removal from upper and lower dentures using a specific dentifrice (Corega Brite). The correlation between biofilm levels on the internal and external surfaces of the upper and lower dentures was also evaluated. A microbiological assay was performed to assess the growth of colony-formed units (cfu) of Candida yeasts on denture surface. Thirty-three patients were enrolled in a 10-week trial divided in two stages: 1 (control) - three daily water rinses within 1 week; 2 - three daily brushings within 3 weeks per tested brush. Internal (tissue) and external (right buccal flange) surfaces of the complete dentures were disclosed (neutral red 1%) and photographed. Total denture areas and disclosed biofilm areas were measured using Image Tool 3.00 software for biofilm quantification. Dentures were boxed with #7 wax and culture medium (CHROMagar Candida) was poured to reproduce the internal surface. Statistical analysis by Friedman's test showed significant difference (p<0.01) between control and brushing stages. No difference was found among the brushes with respect to their efficacy on biofilm removal (p>0.01). Analysis by the Correlation test showed higher r values (B=0.78; MD=0.8341, C=0.7362) for the lower dentures comparing the surfaces (internal and external) and higher r values (B=0.7861, MD=0.7955, C=0.8298) for the external surface comparing the dentures (upper and lower). The results of the microbiological showed no significant difference (p>0.01) between the brushes with respect to the frequency of the species of yeasts (chi-square test). In conclusion, all denture brushes evaluated in this study were effective in the removal of biofilm. There was better correlation of biofilm levels between the surfaces for the lower dentures, and between the dentures for the external surface. There was no significant difference among the brushes

  5. [The preparation of dentition before making removable denture].

    PubMed

    Pesata, P

    1989-01-01

    The authors deals briefly with some important moments in preparing the dentition before making removable denture: parodontological therapy, adjustment of the plane of occlusion and articulation, occlusion cavities and supragingival steps.

  6. [Anatomy and procedure for making an impression for a removable complete denture].

    PubMed

    van Waas, A J

    2011-11-01

    Making an impression of an edentulous jaw is an essential part of producing a removable complete denture, because the proper functioning of the denture is partially dependent on the volume and form of the alveolar ridge and the surrounding soft tissue, in particular the musculature. Before the impression of the maxillary and mandibular jaw is made, insight into the anatomy of the maxilla and the mandible as well as the soft oral tissues is also essential. With respect to this, a 5-phase approach for the impression-making procedure is introduced, which gives guidelines for the fabrication of the preliminary impression, the preliminary cast, the individual impression tray, the final impression and the final cast. In each phase, the concern is to achieve the best possible stability of the denture. Adequate stability can only be achieved by determining the denture borders accurately.

  7. Risk management in clinical practice. Part 6b. Identifying and avoiding medico-legal risks in removable dentures.

    PubMed

    Stilwell, C

    2010-10-09

    The most likely cause of complaint with prosthodontics is a denture that in some way fails to be accepted. A denture that does not perform as the patient expects can give rise to great disappointment and anger. The problem is that acceptance of a denture is not just a technical issue. Success depends on the individual's ability to tolerate and adapt to the denture. It is therefore essential to make the right assessment for the patient from the outset. This includes discovering the patient's priorities and establishing realistic expectations. With the aim of assisting the dental profession in identifying and avoiding medico-legal risks in removable dentures, this article sets out a systematic, diagnostic and collaborative approach to complete and partial denture assessment and treatment.

  8. Fracture Surface Analysis of Clinically Failed Fixed Partial Dentures

    PubMed Central

    Taskonak, B.; Mecholsky, J.J.; Anusavice, K.J.

    2008-01-01

    Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2® lithia-disilicate (Li2O·2SiO2)-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were retrieved and analyzed. Fractography and fracture mechanics methods were used to estimate the stresses at failure in 6 bridges (50%) whose fracture initiated from the occlusal surface of the connectors. Fracture of 1 non-veneered bridge (8%) initiated within the gingival surface of the connector. Three veneered bridges fractured within the veneer layers. Failure stresses of the all-core fixed partial dentures ranged from 107 to 161 MPa. Failure stresses of the veneered fixed partial dentures ranged from 19 to 68 MPa. We conclude that fracture initiation sites are controlled primarily by contact damage. PMID:16498078

  9. Fracture surface analysis of clinically failed fixed partial dentures.

    PubMed

    Taskonak, B; Mecholsky, J J; Anusavice, K J

    2006-03-01

    Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2 lithia-disilicate (Li(2)O x 2SiO(2))-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were retrieved and analyzed. Fractography and fracture mechanics methods were used to estimate the stresses at failure in 6 bridges (50%) whose fracture initiated from the occlusal surface of the connectors. Fracture of 1 non-veneered bridge (8%) initiated within the gingival surface of the connector. Three veneered bridges fractured within the veneer layers. Failure stresses of the all-core fixed partial dentures ranged from 107 to 161 MPa. Failure stresses of the veneered fixed partial dentures ranged from 19 to 68 MPa. We conclude that fracture initiation sites are controlled primarily by contact damage.

  10. The effectiveness of chemical denture cleansers and ultrasonic device in biofilm removal from complete dentures.

    PubMed

    Cruz, Patrícia Costa; Andrade, Ingrid Machado de; Peracini, Amanda; Souza-Gugelmin, Maria Cristina Monteiro de; Silva-Lovato, Cláudia Helena; de Souza, Raphael Freitas; Paranhos, Helena de Freitas Oliveira

    2011-01-01

    Adequate denture hygiene can prevent and treat infection in edentulous patients. They are usually elderly and have difficulty for brushing their teeth. This study evaluated the efficacy of complete denture biofilm removal using chemical (alkaline peroxide-effervescent tablets), mechanical (ultrasonic) and combined (association of the effervescent and ultrasonic) methods. Eighty complete denture wearers participated in the experiment for 21 days. They were distributed into 4 groups (n=20): (1) Brushing with water (Control); (2) Effervescent tablets (Corega Tabs); (3) Ultrasonic device (Ultrasonic Cleaner, model 2840 D); (4) Association of effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush (Bitufo) and water, 3 times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. To quantify the biofilm, the internal surfaces of the maxillary complete dentures were stained and photographed at 45º. The photographs were processed and the areas (total internal surface stained with biofilm) quantified (Image Tool 2.02). The percentage of the biofilm was calculated by the ratio between the biofilm area multiplied by 100 and the total area of the internal surface of the maxillary complete denture. The Kruskal-Wallis test was used for comparison among groups followed by the Dunn multiple-comparison test. All tests were performed respecting a significance level of 0.05. Significant difference was found among the treatments (KW=21.18; P<0.001), the mean ranks for the treatments and results for Dunn multiple comparison test were: Control (60.9); Chemical (37.2); Mechanical (35.2) and Combined (29.1). The experimental methods were equally effective regarding the ability to remove biofilm and were superior to the control method (brushing with water). Immersion in alkaline peroxide and ultrasonic vibration can be used as auxiliary agents for cleaning complete dentures.

  11. The effectiveness of chemical denture cleansers and ultrasonic device in biofilm removal from complete dentures

    PubMed Central

    CRUZ, Patrícia Costa; de ANDRADE, Ingrid Machado; PERACINI, Amanda; de SOUZA-GUGELMIN, Maria Cristina Monteiro; SILVA-LOVATO, Cláudia Helena; de SOUZA, Raphael Freitas; PARANHOS, Helena de Freitas Oliveira

    2011-01-01

    Adequate denture hygiene can prevent and treat infection in edentulous patients. They are usually elderly and have difficulty for brushing their teeth. Objective This study evaluated the efficacy of complete denture biofilm removal using chemical (alkaline peroxide-effervescent tablets), mechanical (ultrasonic) and combined (association of the effervescent and ultrasonic) methods. Material and Methods Eighty complete denture wearers participated in the experiment for 21 days. They were distributed into 4 groups (n=20): (1) Brushing with water (Control); (2) Effervescent tablets (Corega Tabs); (3) Ultrasonic device (Ultrasonic Cleaner, model 2840 D); (4) Association of effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush (Bitufo) and water, 3 times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. To quantify the biofilm, the internal surfaces of the maxillary complete dentures were stained and photographed at 45º. The photographs were processed and the areas (total internal surface stained with biofilm) quantified (Image Tool 2.02). The percentage of the biofilm was calculated by the ratio between the biofilm area multiplied by 100 and the total area of the internal surface of the maxillary complete denture. Results The Kruskal-Wallis test was used for comparison among groups followed by the Dunn multiple-comparison test. All tests were performed respecting a significance level of 0.05. Significant difference was found among the treatments (KW=21.18; P<0.001), the mean ranks for the treatments and results for Dunn multiple comparison test were: Control (60.9); Chemical (37.2); Mechanical (35.2) and Combined (29.1). Conclusion The experimental methods were equally effective regarding the ability to remove biofilm and were superior to the control method (brushing with water). Immersion in alkaline peroxide and ultrasonic vibration can be used as auxiliary agents for

  12. Biomechanical considerations on tooth-implant supported fixed partial dentures

    PubMed Central

    Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

    This article discusses the connection of teeth to implants, in order to restore partial edentulism. The main problem arising from this connection is tooth intrusion, which can occur in up to 7.3% of the cases. The justification of this complication is being attempted through the perspective of biomechanics of the involved anatomical structures, that is, the periodontal ligament and the bone, as well as that of the teeth- and implant-supported fixed partial dentures. PMID:23255882

  13. Comparing masticatory performance between dentate individuals and removable denture wearers

    NASA Astrophysics Data System (ADS)

    Nasseri, G.; Dermawan, T.; Marito, P.; Ariani, N.; Gita, F.; Ono, T.; Kusdhany, L.

    2017-08-01

    Tooth loss replacement with dental prostheses aims to restore stomatognathic function, including masticatory performance. Masticatory performance is one of the factors that affect stomatognathic function and health in general. The aim of this study was to compare the masticatory performance of fully dentate subjects and removable denture wearers and determine which method is most suitable, whether using color-changeable chewing gum or gummy jelly. Subjects were classified into two groups: fully dentate (n=10) and removable denture groups (n=10). Masticatory performance was measured using color-changeable chewing gum with 30, 45 and 60 strokes and gummy jelly with 10, 20 and 30 strokes. A Mann-Whitney analysis was done to compare the masticatory performance of the fully dentate and removable denture groups. There was a significant difference (p<0.05) in masticatory performance between the two groups, both with chewing gum and gummy jelly. Spearman’s correlation was used to analyze the correlation between the chewing gum and gummy jelly measurements. Statistically, a significant correlation (P<0.05) was found between the color-changeable chewing gum and gummy jelly. A removable denture does improve masticatory performance, but it is not able to fully restore masticatory performance comparable to dentate individuals. Color-changeable chewing gum and gummy jelly can differentiate masticatory performance in fully dentate and removable denture groups.

  14. Natural Teeth Replacing Artificial Teeth in a Partial Denture: A Case Report

    PubMed Central

    Satapathy, Sukanta Kumar; Pillai, Ajay; Jyothi, Ramya; Annapurna, P. Durga

    2013-01-01

    The aesthetic replacement of anterior teeth in cases of immediate partial denture is always a challenging work for prosthodontists. There is always problem of matching size, colour, shade and shape of the replaced tooth with those of the natural teeth. It was most difficult to satisfy the patients who have high aesthetic demands. Here is a report of a case where patient’s own natural tooth was used for replacement in an immediate partial denture. An immediate denture is defined as “any removable dental prosthesis which is fabricated for placement immediately, following the removal of a natural tooth/teeth” . Patients with missing anterior teeth lack an impressive appearance aesthetically and as well as psychologically. Tooth loss leads to a certain degree of loss of function. This loss of function might lead to an impairment of oral health which is related to quality of life. An immediate denture can replace 1-16 teeth in either the maxillary or the mandibular arch, or in both arches. The need for the immediate replacement of a missing tooth is more in case of an anterior tooth, where aesthetics is of prime concern. The replacement of an anterior tooth is most technique sensitive, as it includes the patient’s expectations, which include, matching with proper shade, shape and size as those of his/her natural teeth. So, here is a case presentation where modern day patient expectations were taken into consideration. PMID:24086926

  15. Natural teeth replacing artificial teeth in a partial denture: a case report.

    PubMed

    Satapathy, Sukanta Kumar; Pillai, Ajay; Jyothi, Ramya; Annapurna, P Durga

    2013-08-01

    The aesthetic replacement of anterior teeth in cases of immediate partial denture is always a challenging work for prosthodontists. There is always problem of matching size, colour, shade and shape of the replaced tooth with those of the natural teeth. It was most difficult to satisfy the patients who have high aesthetic demands. Here is a report of a case where patient's own natural tooth was used for replacement in an immediate partial denture. An immediate denture is defined as "any removable dental prosthesis which is fabricated for placement immediately, following the removal of a natural tooth/teeth" . Patients with missing anterior teeth lack an impressive appearance aesthetically and as well as psychologically. Tooth loss leads to a certain degree of loss of function. This loss of function might lead to an impairment of oral health which is related to quality of life. An immediate denture can replace 1-16 teeth in either the maxillary or the mandibular arch, or in both arches. The need for the immediate replacement of a missing tooth is more in case of an anterior tooth, where aesthetics is of prime concern. The replacement of an anterior tooth is most technique sensitive, as it includes the patient's expectations, which include, matching with proper shade, shape and size as those of his/her natural teeth. So, here is a case presentation where modern day patient expectations were taken into consideration.

  16. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

    PubMed Central

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  17. Successful flexible bronchoscopic management of a large-sized aspirated partial denture.

    PubMed

    Jamshed, Nayer; Madan, Karan; Ekka, Meera; Guleria, Randeep

    2014-03-20

    A 48-year-old male patient presented to the emergency room with a history of chest pain and breathlessness. Chest X-ray demonstrated a large radio-opaque foreign body in relation to the proximal right bronchial tree. The patient subsequently revealed a history of a misplaced denture 4 months previously. Urgent flexible bronchoscopy (FB) examination demonstrated a large partial denture impacted in the right intermediate bronchus, which was removed successfully using a flexible bronchoscope. Although rigid bronchoscopy (RB) is the procedure of choice for large-sized and impacted airway foreign bodies, the present case highlights the utility of FB in airway foreign body removal. In clinically stable patients with foreign body inhalation, FB can be employed initially as it is an outpatient and cost-effective procedure which can obviate the need for administration of general anaesthesia.

  18. Avoiding osseous grafting in the atrophic posterior mandible for implant-supported fixed partial dentures: a report of 2 cases.

    PubMed

    Flanagan, Dennis

    2011-12-01

    Bone atrophy occurs after tooth extraction in the posterior mandible, placing the mandibular canal and its neural, arterial, and venous contents closer to the osseous facial aspect and the coronal crest. This proximity places the structure in danger of damage when dental implants are surgically placed to support fixed or removable prostheses. Several options are available to treat these areas for implant-supported fixed and removable complete or partial dentures. Osseous grafting and ridge expansion are surgical options that enable acceptance of standard sized dental implants but have serious morbidities. Additionally, vertical osseous augmentation is not predictable at this time. Narrow diameter dental implants can be placed to avoid the mandibular canal, but some bone volume situations preclude this. Very wide and very short (6.5 × 5 mm) dental implants may be placed at an angle in atrophic sites to successfully support fixed partial dentures. An anterior guidance occlusal scheme may be used in maxillary dentate patients or group function in maxillary complete denture patients. A 100 micron occlusal relief in fixed partial dentures in dentate patients may be required to account for natural tooth intrusion and to prevent occlusal overload of the implant-supported partial denture.

  19. Partial denture metal framework may harbor potentially pathogenic bacteria

    PubMed Central

    Bernardes, Luciano Angelo de Souza; Gomes, Sabrina Carvalho; Silva, Alecsandro Moura

    2015-01-01

    PURPOSE The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2. CONCLUSION The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions. PMID:26816577

  20. A Collapsible Partial Denture for a Patient with Limited Mouth Opening Induced by Scleroderma: A Clinical Report.

    PubMed

    Gözde Türk, Ayşe; Ulusoy, Mübin

    2015-06-01

    A limited opening of the mouth is defined as microstomia. Microstomia is caused by burns, postoperative head and neck trauma, radiotherapy, or scleroderma. The prosthetic treatment of microstomia presents particular challenges, and patients often complain of an inability to insert or remove the prosthesis. The cause and severity of microstomia can influence the approach to treatment. Different treatment methods have been suggested, including the fabrication of two-piece partial dentures. This clinical report describes the construction of a sectional impression tray and a collapsed partial denture using a hinge attachment for a patient with microstomia.

  1. Conservative inlay fixed partial denture: a clinical and laboratory technique.

    PubMed

    Ajlouni, Raed; Ajlouni, Khaldoun; Oonsombat, Charuphan; Ruder, Gary

    2005-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPDs) offer a clinical alternative for the restoration of single missing teeth and short-span posterior and anterior FPDs. This treatment modality is conservative and cost-efficient. The continuous improvement of adhesives and resin-based composite systems makes this type of restoration successful with good esthetic and functional results. This article reports the case of a patient who received an FRC FPD as a treatment modality and illustrates the clinical procedure as well as a new laboratory technique utilizing a clear matrix for the fabrication of the prosthesis.

  2. Rotational path partial denture design: a 10-year clinical follow-up--Part I.

    PubMed

    Jacobson, T E

    1994-03-01

    A conventional removable partial denture that uses a straight path of placement requires that all rests and clasps be seated simultaneously. The incorporation of a dual, curved, or rotational path of placement permits one portion of the framework to be seated first, followed by the remainder of the framework. This procedure usually permits a reduction in the number of clasps in the framework without compromising the biomechanical properties of the prosthesis. Rotational path designs that eliminate clasps reduce tooth coverage by components and often enhance esthetics, thereby contributing to improved patient acceptance.

  3. The all-ceramic, inlay supported fixed partial denture. Part 2. Fixed partial denture design: a finite element analysis.

    PubMed

    Thompson, M C; Field, C J; Swain, M V

    2011-09-01

    The clinical use of all-ceramic crowns and fixed partial dentures has seen widespread adoption over the past few years due to their increasing durability and longevity. However, the application of inlays as an abutment design has not been as readily embraced because of their relatively high failure rates. With the use of an idealized inlay preparation design and prosthesis form which better distributes the tensile stresses, it is possible to utilize the inlay as support for an all-ceramic fixed partial denture. Utilizing a three-dimensional finite element analysis, a direct comparison of the inlay supported all-ceramic bridge against the traditional full crown supported all-ceramic bridge is made. The results demonstrate that peak stresses in the inlay bridge are around 20% higher than in the full crown supported bridge with von Mises peaking at about 730 MPa when subjected to theoretical average maximum bite force in the molar region of 700 N, which is similar to the ultimate tensile strengths of current zirconia based ceramics.

  4. Zirconia-based fixed partial dentures: a clinical review.

    PubMed

    Bachhav, Vinay Chila; Aras, Meena Ajay

    2011-02-01

    Ceramics have a long history in fixed prosthodontics of achieving optimal esthetics. Yttrium tetragonal zirconia polycrystal (Y-TZP)-based systems are a recent addition to the high-strength, all-ceramic systems used for crowns and fixed partial dentures. CAD/CAM-produced, Y-TZP-based systems are in considerable demand in esthetic and stress-bearing regions. The highly esthetic nature of zirconia coupled with its superior physical properties and biocompatibility have resulted in restorative systems that meet the demands of today's patients. Undoubtedly, these systems are considered to be prospective replacements for metal-ceramic restorations. This article reviews relevant contemporary literature regarding all-ceramic materials and systems and discusses their material properties, biocompatibility, advances in cementation, and more with special emphasis on clinical survival. The article also aims to provide recommendations for their use.

  5. Telescopic Overdenture and Implant Supported Fixed Partial Denture: A Pragmatic Treatment Approach

    PubMed Central

    Dede, Doğu Ömür; Cenk Durmuşlar, M.; Şahın, Onur; Köroğlu, Ayşegül; İşısağ, Özer

    2015-01-01

    This case report presents a patient who had been rehabilitated with a telescopic overdenture and implant supported fixed partial denture (ISFPD). The treatment process was as follows: (1) fabricating telescopic crowns and overdenture prosthesis for the lower jaw and a temporary complete denture for the upper jaw, (2) using the temporary denture as diagnostic and surgical guide to optimize dental implant placement, and (3) fabricating ISFPD for the upper jaw. Using the patient's existing or temporary denture not only serves as an alternative surgical guide to calibrate the dental implant locations but also helps to finish the restoration at desired dimension, size, and anatomic form. PMID:26106491

  6. Fixed partial dentures investigated by optical coherent tomography

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda; Todea, Carmen; Hughes, Mike; Tudorache, Florin; Podoleanu, Adrian G.

    2008-02-01

    Fixed partial prostheses as integral ceramics, integral polymers, metal ceramics or metal polymers bridges, are mainly used in the frontal part of the dental arch (especially the integral bridges). They have to satisfy high stress requirements as well as esthetic. The masticatory stress may induce fractures of the bridges. These may be triggered by initial materials defects or by alterations of the technological process. The fractures of these bridges lead to functional, esthetic and phonetic disturbances which finally render the prosthetic treatment inefficient. The purpose of this study is to evaluate the capability of en-face optical coherence tomography (OCT) in detection and analysis of possible fractures in several integral fixed partial dentures. The materials used were represented by several fixed partial prostheses, integral ceramics, integral polymers, metal ceramics and metal polymers bridges. In order to discover the defects, scanning was performed from incisal, vestibular, oral and cervical directions material defects such as fractures and pores were investigated using OCT. In conclusion, en-face OCT has proven as a valuable non invasive method to investigate fixed partial prostheses before their insertion in the oral cavity.

  7. Corrosion considerations in the brazing repair of cobalt-based partial dentures.

    PubMed

    Luthy, H; Marinello, C P; Reclaru, L; Scharer, P

    1996-05-01

    Cobalt-based alloys (Co-Cr-Mo) are usually used in dentistry as frameworks for removable partial dentures. In their basic form these structures function successfully. However, modifications or repairs of the frameworks may reduce their resistance to corrosion and, as a consequence, may provoke biologic reactions in the soft tissues. These reactions may be the result of different types of alloys that contact each other and, in the presence of saliva (based on potential differences), produce a galvanic cell. In this study, a clinical situation after repair of a removable partial denture was examined. The metallographic study of the prosthesis revealed a brazed zone where a gold braze was joining the Co-Cr-Mo framework with a Co-Cr-Ni type alloy (without Mo). The latter revealed signs of corrosion. Various electrochemical parameters (Ecorr, Ecouple, icorr, icouple) of these alloys were analyzed in the laboratory. The Co-Cr-Ni alloy had the lowest nobility and underwent galvanic corrosion in a galvanic couple with gold braze.

  8. Biomechanical factors related to occlusal load transfer in removable complete dentures.

    PubMed

    Żmudzki, Jarosław; Chladek, Grzegorz; Kasperski, Jacek

    2015-08-01

    Owing to economic conditions, removable dentures remain popular despite the discomfort and reduced chewing efficiency experienced by most denture wearers. However, there is little evidence to confirm that the level of mucosal load exceeds the pressure pain threshold. This discrepancy stimulated us to review the current state of knowledge on the biomechanics of mastication with complete removable dentures. The loading beneath dentures was analyzed in the context of denture foundation characteristics, salivary lubrication, occlusal forces, and the biomechanics of mastication. The analysis revealed that the interpretation of data collected in vivo is hindered due to the simultaneous overlapping effects of many variables. In turn, problems with determining the pressure beneath a denture and analyzing frictional processes constitute principal limitations of in vitro model studies. Predefined conditions of finite element method simulations should include the effects of oblique mastication forces, simultaneous detachment and sliding of the denture on its foundation, and the stabilizing role of balancing contacts. This review establishes that previous investigations may have failed because of their unsubstantiated assumption that, in a well-working balanced occlusion, force is only exerted perpendicular to the occlusal plane, allowing the denture to sit firmly on its foundation. Recent improvements in the simulation of realistic biomechanical denture behavior raise the possibility of assessing the effects of denture design on the pressures and slides beneath the denture.

  9. Influence of the renewal of removable dentures on oral health related quality of life.

    PubMed

    Bonnet, Guillaume; Batisse, Cindy; Segyo, Jean W; Veyrune, Jean-Luc; Nicolas, Emmanuel; Bessadet, Marion

    2016-01-01

    The renewal of removable dentures is often suggested to denture wearers subject to discomfort. However, the impact of this rehabilitation on patients' oral health related quality of life and their removable dentures related satisfaction is still unknown. This study was aimed at assessing these patient-centered outcomes and the potential impact of different factors. A cohort of 116 patients in need of removable dental prostheses rehabilitation was recruited at a dental hospital over a period of 1 year. The subjects were separated into two groups according to their prosthesis experience (group in need of removable dentures renewal/group needing an removable dentures for the first time). Subjects were asked to answer the "Geriatric Oral Health Assessment Index" (GOHAI) and the "McGill Denture Satisfaction Instrument" before and after a prosthesis integration period (9-12 weeks). GOHAI scores were slightly higher for patients with removable dentures renewal (from 40.6 ± 10.3 to 47.1 ± 10.0, p < 0.001), independently of the type of prosthetic rehabilitation. However, the scores of the GOHAI functional field did not change. Subjects with no removable dentures experience presented an increase in their functional GOHAI score (p < 0.001). Regarding patient removable dentures related satisfaction, only the "Esthetic" (p < 0.001), "Chewing efficiency" (p < 0.001) and "Oral condition" (p < 0.01) items increased after prosthesis renewal. This study showed that renewing removable dentures only moderately improved the oral health related quality of life and removable dentures related satisfaction of patients, regardless of age, gender or type of rehabilitation. Other tasks are necessary such as the analysis of physiological parameters and qualitative research on patient's expectations.

  10. Evaluation of procedures employed for the maintenance of removable dentures in elderly individuals.

    PubMed

    Barreiro, Diego Marques; Scheid, Patrícia Alves; May, Liliana Gressler; Unfer, Beatriz; Braun, Katia Olmedo

    2009-01-01

    The objective of the present study was to evaluate the behaviour of the wearers of removable dentures in relation to cleaning and maintaining the prosthesis. Two hundred and thirty-one people were interviewed, most of whom were females, over 60 years of age and participants in the Center for Integrated Study and Support to the Elderly. After analysing the responses, it was verified that most people brush their dentures three times a day using dentifrice and only go to the clinician when they have a complaint. They do not receive follow-up appointments for checkups, do not use immersion cleaners for their dentures and do not remove their dentures during the night. It was concluded that the study sample did not receive proper orientation for the conservation of removable dentures, which may consequently reduce the useful life of dentures and cause social and functional problems.

  11. Effects of wearing and removing dentures on oropharyngeal motility during swallowing.

    PubMed

    Onodera, S; Furuya, J; Yamamoto, H; Tamada, Y; Kondo, H

    2016-11-01

    Wearing dentures and dysphagia are common in older individuals; however, it is still unknown how dentures affect oral and pharyngeal swallowing. The purpose of this study was to reveal the effects of wearing and removing dentures on oropharyngeal movements during pharyngeal swallowing in the feeding sequence of solid food. Participants were 25 edentulous volunteers (nine men, 16 women; mean age 76·2 years) who wore complete dentures. The test food was minced agar jelly containing barium sulphate. Subjects were instructed to feed and swallow the test food with or without dentures during observation using videofluorography. We quantitatively evaluated the range, distance and duration of oropharyngeal movements during pharyngeal swallowing. When dentures were absent, the range of mandible and hyoid movements were significantly expanded in the anterosuperior direction, and the range of laryngeal movement was significantly expanded in the anterior direction. Additionally, the posterior pharyngeal wall contraction and upper oesophageal sphincter opening significantly increased. In addition, the distances of the mandible, hyoid and laryngeal movements and the mandibular duration were significantly extended when dentures were absent. No significant differences were observed in the duration of movements of other organs between wearing and removing dentures. The hyoid bone, larynx, posterior pharyngeal wall and upper oesophageal sphincter do not change their duration of movements when dentures were removed but, rather, expand their range of movement. This might be a spatial change of oropharyngeal movement to avoid temporal changes in pharyngeal swallowing when dentures were absent in edentulous older individuals. © 2016 John Wiley & Sons Ltd.

  12. Hamular frenum modification: a removable denture prosthesis retention and stability enhancement.

    PubMed

    Massad, J J; Anderson, J F

    2001-04-01

    A removable denture prosthesis, whether partial or complete, often requires preprosthetic surgery to achieve optimum stabilization and retention. While the hamular frenum may produce significant dynamic dislodging forces, a literature review did not reveal any reports dealing with this problem. A hamular frenum reduction surgical procedure using the free autogenous gingival graft procedure is described. Prosthetic function may be enhanced by eliminating the dynamic disrupting force of the hamular frenum along with improving posterior maxillary tuberosity contour and, as necessary, premaxillary form, allowing these contours to work in concert to develop a "cupping" stabilizing and retentive complex.

  13. Development of a device to study fatigue life of fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Gutierrez, S. C.; Meseguer, M. D.; Estal, R.; Folguera, F.; Vidal, V.

    2012-04-01

    Fixed partial dentures can be fabricated by means of different materials and with different manufacturing processes. In order to establish possible differences among them, their behaviour, as fatigue life or cement shear bond strength, have to be evaluated. This article presents a modular, economic and robust device to evaluate fixed partial dentures and dental crowns. A base to support the fixed partial dentures and a device to simulate masticatory loads have been developed. The device has got a simple design. It is based on a pneumatic piston, with a pressure regulator to control masticatory loads. On a first stage, only vertical forces have been taking into account. However, the device will allow simulating tangential masticatory loads on the other axis, studying the behaviour of the fixed partial dentures submerged in a solution similar to saliva, changing masticatory load application, etc. with little modifications.

  14. Strength of zirconia fixed partial dentures: review of the literature

    PubMed Central

    GARGARI, M.; GLORIA, F.; CAPPELLO, A.; OTTRIA, L.

    2011-01-01

    SUMMARY Objective The aim of this study is a systematic review of the literature on the strength and long-term behavior of zirconia FPDs. Methods The literature search was performed using as the primary source the Medline database. Were also imposed a set of inclusion and exclusion criteria in order to narrow the search to differentiate the two distinct parts in which it was structured the review. In addition, MeSH terms were applied to further refine the choice of articles more relevant to the review. In the part of the review concerning the long-term behavior of zirconia fixed partial dentures were considered useful only those studies with a minimum follow-up of one year. Results The search provided a total of 813 articles, but only 25 were considered for the review because they were the only ones who satisfied search criteria. In particular, 13 items relate to the mechanical strength of zirconia prostheses and 12 regarding the long term behavior of zirconia FPDs. The resistance values also exceed the 2000 N while the survival rate reaches to almost 94%. Conclusions Based on this review, Zirconia FPDs can be considered reliable products in both the anterior and posterior fields with survival rates comparable to traditional metal-ceramic prostheses. PMID:23285392

  15. Rotational path partial denture design: a 10-year clinical follow-up--Part II.

    PubMed

    Jacobson, T E

    1994-03-01

    A review of the rotational path removable partial denture design concept has been presented. The rigid direct retainers used in these designs satisfy the basic requirements of clasp designs. The reported results of a survey of the members of The Academy of Prosthodontics may provide insight into the reasons for reluctance on the part of some practitioners to use the concept more often when indicated. Possible reasons include the following: lack of sufficient understanding of the concept, difficulty in obtaining knowledgeable laboratory support, absence of documented evidence of long-term clinical success, and a general lack of confidence in the efficacy of the procedure as described in the literature. This article presents references that are available to improve the understanding of technicians and dentists with regard to the rotational path concept. In addition, several patients followed up for 10 or more years demonstrated long-term clinical success.

  16. Composite veneering of metal based fixed partial dentures.

    PubMed

    Rosentritt, M; Behr, M; Brückner, H; Handel, G

    2005-08-01

    The aim of this in vitro study was to determine the thermal mechanical properties of veneering composites after polymerization with the appropriate polymerization device. Fracture tests were performed to investigate the effect on fixed partial dentures (FPDs). Dynamic mechanical thermal analysis was used to determine the temperature-dependent mechanical properties. To approximate the clinical situation, the fracture resistance of three-unit metal-based FPDs with different composite veneering was investigated after a simulated 5-year oral wearing period. The restorations were made of a high gold alloy and veneered with three different composites. To determine the influence of fabrication, one composite was used in a light-polymerizing and a heat/pressure-curing version and, in addition, a newly developed heat protection paste was used. After a 5-year simulation period, the fracture resistance was determined. The storage modulus varied between 14268 N mm(-2) (Belleglass) and 6616 N mm(-2) (Sinfony). Adoro showed no significant differences between light curing (9155 N mm(-2)) and heat curing (8184 N mm(-2)) variations. The Adoro-veneering with the heat protection paste showed the highest median fracture strength (1700 N), followed by Adoro LC (1555 N), Belleglass (1051 N), Adoro HP (1150 N) and Sinfony (909 N). The most common failure type occurring in all FPDs was a cracking of the composite, exposing the metal framework. All FPDs showed stress cracking of the composite. The heat protection paste seemed to reduce the crack formation after fabrication and increased the fracture resistance of the composite veneering. Stress cracking after thermal cycling and mechanical loading affected all composites, but all veneered three-unit alloy FPDs showed a fracture resistance sufficient for posterior application.

  17. Adaptation of all-ceramic fixed partial dentures

    PubMed Central

    Borba, Márcia; Cesar, Paulo F.; Griggs, Jason A.; Della Bona, Álvaro

    2011-01-01

    Objectives To measure the marginal and internal fit of three-unit fixed partial dentures (FPDs) using the micro-CT technique, testing the null hypothesis that there is no difference in the adaptation between the ceramic systems studied. Methods Stainless steel models of prepared abutments were fabricated to design the FPDs. Ten FPDs were produced from each framework ceramic (YZ - Vita In-Ceram YZ and IZ - Vita In-Ceram Zirconia) using CEREC inLab according to the manufacturer instructions. All FPDs were veneered using the recommended porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sections images. Five measuring locations were used as follows: MG – marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. The horizontal marginal discrepancy (HMD) was evaluated in another set of images. Results were statistically analyzed using ANOVA and Tukey tests (α=0.05). Results The mean values for MG, CA, AW, OA and HMD were significantly different for all tested groups (p<0.05). IZ exhibited greater mean values than YZ for all measuring locations except for AW and AOT. OA showed the greatest mean gap values for both ceramic systems. MG and AW mean gap values were low for both systems. Significance The ceramic systems evaluated showed different levels of marginal and internal fit, rejecting the study hypothesis. Yet, both ceramic systems showed clinically acceptable marginal and internal fit. PMID:21920595

  18. Aerobic bacteria in the oral cavity of patients with removable dentures.

    PubMed

    Daniluk, T; Fiedoruk, K; Sciepuk, M; Zaremba, M L; Rozkiewicz, D; Cylwik-Rokicka, D; Tokajuk, G; Kedra, B A; Anielska, I; Stokowska, W; Górska, M; Kedra, B R

    2006-01-01

    Determination of bacterial composition in the oral cavity of patients with removable dentures and with own dentition (without dentures). Bacteriological investigations were performed in 55 patients from the department of internal medicine (32 diabetic patients) and 40 patients treated in surgical department (25 patients with malignancy). Palate mucosa and tongue dorsa swabs were collected from two groups of patients, and additionally swabs from mucosal part of denture surfaces in prosthetic patients. Cultures in oxygenic and microaerophilic (5% CO2) conditions were conducted on solid non-selective and selective media as well as media enriched with 5% sheep blood. Standard procedures of bacterial culture and identification were applied. Among 95 of examined patients, 57 (60.0%) with removable dentures and 38 (40.0%) had their own dentition. As far as prosthetic patients were concerned, the rate of bacterial isolations from palate, tongue dorsa and denture plaque swabs were generally comparable (p > 0.05); in number and species compositions. Statistically significant differences were observed in the bacterial composition of denture plaques, palate and tongue dorsa in patients with and without abdominal cancers. Patients without cancer did not reveal staphylococci and enteric bacteria in the samples from a various sites of their oral cavities. These bacteria were most common in cancer patients. Similar (in number and species) composition of bacteria occurred in palate and tongue swabs in patients without dentures (p > 0.05). The incidence rate of aerobic bacteria in denture plaques and palatal mucosa of patients with (37/57; 64.9%) and without (20/57; 35.1%) denture associated stomatitis were comparable (except for Neisseria spp.). 1) Generally, there were no statistically significant differences in species composition of bacteria isolated from the hard palate and tongue dorsa in patients with and without removable dentures. 2) Staphylococcus spp. and Gram

  19. Broncho-Oesophageal Fistula (BOF) Secondary to Missing Partial Denture in an Alcoholic in a Low Resource Country.

    PubMed

    Odigie, Vincent I; Yusufu, Lazarus Md; Abur, Peter; Edaigbini, Sunday A; Dawotola, David A; Mai, Ahmad

    2011-01-01

    The clinical course of a missing partial denture with secondary BOF in an alcoholic is presented. In the index case we report an exceptional clinical course of a patient who did not ascribe his symptoms to his ''missing'' dentures for several years, the odontologist who replaced an unrecovered denture, and the generalist who administered the barium swallow in an unsuspected BOF. Preoperative optimization of the patient was by blenderized local feeds through a feeding tube gastrostomy and by chest physiotherapy. Extraction of the denture and closure of fistula were done through a right thoracotomy. The importance of a high index of clinical suspicion of BOF in a low resource setting to avoid the morbidity and mortality associated with missing dentures is discussed. Odontologists, caregivers and clinicians must educate patients on the hazards of missing dentures and cases of missing / lost dentures should be adequately investigated / explored in the patient's history and clinical assessment before they are replaced.

  20. Implant support for removable partial overdentures: a case report.

    PubMed

    Halterman, S M; Rivers, J A; Keith, J D; Nelson, D R

    1999-01-01

    Functional stability and the preservation of remaining alveolar bone are primary, and often elusive, goals when restoring the partially edentulous arch. The incorporation of dental implants for the partial support of removable prostheses offers a practical adjunct in the fulfillment of these objectives. Planning for complex courses of treatment that include dental implants requires close coordination between the surgeon and the restorative dentist. Decisions that deal with type, location, size, number of implant fixtures, and design of the prosthesis are critical. All of these areas must be discussed and established as acceptable to the patient and each clinician before the initiation of treatment. In this report, we present a course of patient treatment in which a removable partial denture is supported by natural remaining teeth in conjunction with osseointegrated implants.

  1. Modern application of the Skinner vertical movement stress director for distal extension partial removable dental prostheses: A clinical report.

    PubMed

    Schulz, Kyle S; Downs, Donald; Cagna, David R

    2013-07-01

    This article describes the prosthetic rehabilitation of a partially edentulous patient with a partial removable dental prosthesis (PRDP) designed to dissipate stress transmission to the denture foundation and abutment teeth. The Skinner stress director is considered an alternative design for managing partially edentulous patients.

  2. Immediate fixed partial denture after tooth extraction in patients with systemic diseases: A clinical report.

    PubMed

    Kang, Hyun Sun; Lee, Su Young

    2016-12-01

    For patients with systemic diseases who face difficulties visiting dental clinics, wearing fixed partial denture in the anterior region on the same day of tooth extraction can reduce the total period of treatment and the number of visits, as well as post-treatment psychological effect on the patient.

  3. Immediate fixed partial denture after tooth extraction in patients with systemic diseases: A clinical report

    PubMed Central

    2016-01-01

    For patients with systemic diseases who face difficulties visiting dental clinics, wearing fixed partial denture in the anterior region on the same day of tooth extraction can reduce the total period of treatment and the number of visits, as well as post-treatment psychological effect on the patient. PMID:28018570

  4. [Two years clinical observation of anterior all zirconia ceramic resin bonded fixed partial dentures].

    PubMed

    Zhou, Tuan-Feng; Zhang, Gui-Rong; Wang, Xin-Zhi

    2010-03-01

    To observe the restoration effect of anterior all zirconia ceramic resin bonded fixed partial dentures, and to find a new fixed restorative method for restoring one or two missing anterior teeth. Twenty-nine missing anterior teeth from twenty-three patients were restored with all zirconia ceramic resin bonded fixed partial dentures, and restorations were devided in to two groups according to the number of retainers, i.e. the single-retainer group and the two-retainer group. The integrity, secondary caries, marginal shade and color match of the restorations were evaluated with the standard of American Public Health Association (APHA). The average period of observation was 22 months. One restoration from the two-retainer group failed, two restorations from the single-retainer group failed. The shade of two restorations were evaluated as discernable whiter compared to adjacent teeth. There was no secondary caries and marginal shade. The two year success rate of anterior all zirconia ceramic resin bonded fixed partial dentures was 90% (26/29). All zirconia ceramic resin bonded fixed partial dentures used for less than two anterior missing teeth can achieved definite aesthetic effect and physiologic function. It was a new type of fixed restoration for anterior missing teeth. However, to determine long-term result of this restoration more data are needed.

  5. Partial denture prosthodontic procedures employed by practising graduates of the University of the Witwatersrand, Johannesburg.

    PubMed

    Dullabh, H D; Slabbert, J C; Becker, P J

    1993-03-01

    This study sought answers to the following two questions related to the teaching of partial denture prosthodontics in the Department of Prosthetic Dentistry at the University of the Witwatersrand, Johannesburg (Wits). Firstly, do practising graduates from Wits assiduously apply, or do they perhaps ignore, the concepts, principles, and practices taught to them at undergraduate level? Secondly, is there any merit in providing additional tutorials on partial denture prosthodontics to undergraduate students at Wits? A questionnaire was mailed to dentists who had graduated at Wits between 1979 and 1986. This sample of 302 subjects was divided into two groups: Group I--those who had graduated between 1979 and 1982; Group II--those who had graduated between 1983 and 1986 and had received additional tutorials on partial denture design. The results suggest that a wide gap exists between faculty beliefs about partial denture design and fabrication and the methods used in general dental practice. Moreover, additional tutorials had some effect on the attitudes and practices of the respondents.

  6. A Technique for Removing Implant-Retained Denture: Direct Relining Complication

    PubMed Central

    Duran, İbrahim; Yilmaz, Betül; Ural, Çağrı

    2015-01-01

    The aim of this case report is to present a technique for removing the denture which locked to ball-attachment because of excessive hard relining resin material flows around the ball-attachment. An alternative method was used in the present case. A cylindrical resin was removed with a diamond bur at the level of matrix and by this way the matrix was removed safely. The advantage of the presented method is that it may be extended to other clinical situations when facing a similar complication for implant supported dentures and also that the technique is simple and does not require special equipment. PMID:26199761

  7. A Technique for Removing Implant-Retained Denture: Direct Relining Complication.

    PubMed

    Duran, İbrahim; Yilmaz, Betül; Ural, Çağrı

    2015-01-01

    The aim of this case report is to present a technique for removing the denture which locked to ball-attachment because of excessive hard relining resin material flows around the ball-attachment. An alternative method was used in the present case. A cylindrical resin was removed with a diamond bur at the level of matrix and by this way the matrix was removed safely. The advantage of the presented method is that it may be extended to other clinical situations when facing a similar complication for implant supported dentures and also that the technique is simple and does not require special equipment.

  8. Evaluating the efficacy of denture cleansing materials in removal of tea and turmeric stains: An in vitro study.

    PubMed

    Makhija, Priyanka P; Shigli, Kamal; Awinashe, Vaibhav

    2016-01-01

    Extrinsic staining of acrylic resin dentures could be a major esthetic problem for denture wearers. Tea, coffee, cola, turmeric, and tobacco often cause extrinsic staining of dentures. To evaluate the efficacy of various denture cleansing materials in the removal of tea and turmeric stains and to compare the efficacy of those denture cleansers with each other in the removal of tea and turmeric stains. Heat-cured acrylic resin specimens were stained using tea and turmeric solutions. The spectrophotometer was used to determine the reflectance values of the samples and to evaluate the efficacy of various denture cleansing materials in removal of tea and turmeric stains. Three denture cleansers, namely, sodium hypochlorite, Safe plus, and Clinsodent were used in the study. Water was used as a control. ANOVA test and post hoc Tukey's test were used to determine the statistical difference between the groups. A statistically significant difference was found (p ≤ 0.05) between the different denture cleansing materials used. Products containing sodium perborate along with trisodium phosphate had the highest stain removing capability. It was found that all the denture cleansing materials used in the study were effective in removing tea and turmeric stains. Products containing sodium perborate along with trisodium phosphate had a comparatively greater stain removal capability than products containing sodium perborate along with sodium bicarbonate followed by products containing sodium hypochlorite followed by water (control).

  9. Partial denture design comparisons between inexperienced and experienced undergraduate students and the teaching staff of a UK dental school.

    PubMed

    Johnson, A; Wildgoose, D G

    2010-09-25

    This study aimed to assess the ability of inexperienced and experienced BDS students and teachers of removable partial denture (RPD) design, to prescribe/design RPDs for an identical partial denture case. Second and fourth/fifth year BDS students and experienced teachers of RPD design were selected to provide a treatment plan for a patient requiring RPDs using identical models. The designs produced were compared against a design produced by the authors before the study began. Not one design for the 100 participants matched the author's design. Under 30% of second year students surveyed the models before designing. Only a small percentage of the participants indicated the path of insertion and removal they had chosen and less than half the student groups and only 60% of the staff group provided clear, correct instructions to the technician. Large disagreements existed between the individuals within groups and between individual groups regarding the selection of component parts. There were wide differences in opinion among the undergraduate student groups as to which are the best design options for particular cases. Teachers of RPD design were found to be far from confident and have no consensus of opinion when designing RPDs.

  10. Alkaline Peroxides Versus Sodium Hypochlorite for Removing Denture Biofilm: a Crossover Randomized Trial.

    PubMed

    Peracini, Amanda; Regis, Rômulo Rocha; Souza, Raphael Freitas de; Pagnano, Valéria Oliveira; Silva, Cláudia Helena Lovato da; Paranhos, Helena de Freitas Oliveira

    2016-01-01

    This study evaluated the efficacy of cleanser solutions on denture biofilm removal by a crossover randomized clinical trial. Thirty two edentulous patients were instructed to brush their dentures (specific brush and liquid soap) three times a day (after breakfast, lunch and dinner) and to soak them (≥ 8 h) in: (C) control -water; (AP): alkaline peroxide; or (SH) 0.5% sodium hypochlorite. Each solution was used for 21 days (three cycles of 7 days). At the end of each cycle, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (HX1 - Sony). Areas (total and stained biofilm) were measured (Image Tool software) and the percentage of biofilm calculated as the ratio between the area of the biofilm multiplied by 100 and total surface area of the internal base of the denture. Data were compared by means of generalized estimating equation (α=5%) and multiple comparisons (Bonferroni; α=1.67%). Immersion in SH reduced biofilm (%) (8.3 ± 13.3B) compared to C (18.2 ± 14.9A) and AP (18.2 ± 16.6A). The 0.5% sodium hypochlorite solution was the most efficacious for biofilm removal. Alkaline peroxides may not lead to further biofilm removal in patients with adequate denture maintenance habits.

  11. Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures.

    PubMed

    Derafshi, Reza; Bazargani, Abdollah; Ghapanchi, Jannan; Izadi, Yazdan; Khorshidi, Hooman

    2017-01-01

    Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran. The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software. Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004). Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection.

  12. Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures

    PubMed Central

    Derafshi, Reza; Bazargani, Abdollah; Ghapanchi, Jannan; Izadi, Yazdan; Khorshidi, Hooman

    2017-01-01

    Aims and Objectives: Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran. Materials and Methods: The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software. Results: Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004). Conclusions: Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection. PMID:28852636

  13. Rehabilitation of oral function with removable dentures--still an option?

    PubMed

    Xie, Q; Ding, T; Yang, G

    2015-03-01

    Tooth loss is a chronic disability, which makes it difficult for patients to perform essential tasks such as eating, communicating with others and socialising. Numerous studies have revealed and addressed the recent rapid development of various prosthodontic materials and treatment patterns. Oral rehabilitation with dentures exerts a great influence on people's daily life and has tremendous social implications. Dentures help to restore an individual's sense of normality and ability to interact normally. With the introduction and progression of implant technology, many troublesome issues can now be solved simply. Nowadays, more and more attention has been paid to new trends (implant-assisted restoration and fixed prostheses). However, removable dentures may be a more appropriate solution under some circumstances, such as if they are a patient's preferred option, if remaining oral tissues are in poor condition, or if they provide the most cost-effective form of treatment. Thus, removable dentures are still an option for the rehabilitation of oral function. The purpose of this article was to retrospectively review the applications of removable dentures and to emphasise their indispensable status. © 2014 John Wiley & Sons Ltd.

  14. Mandibular Kennedy Class I partial denture management by broad stress distribution philosophy (radiographic assessment).

    PubMed

    Abd El-Khalik, Mohammed M; El Mekawy, Nesreen H; El-Kasaby, Sally S

    2016-01-01

    The objective of this study was radiographic assessment of the premolar teeth abutments alveolar bone resorption in mandibular Kennedy Class I removable partial denture (RPD) utilizing the broad stress distribution philosophy, either designed with multiple circlet clasp or compound Aker clasp. Twelve patients were enrolled for this study with upper completely edentulous arch against mandibular Kennedy Class I ridges posterior to the second premolar. The patients were divided into two groups according to the type of the clasp assembly design used, where the mandibular Kennedy Class I RPD was designed with multiple circlet clasp and compound Aker clasp assemblies for Groups I and II, respectively. The abutment alveolar bone resorption was evaluated radiographically after 1(st) 6, 2(nd) 6, and 12 months of mandibular Kennedy Class I RPD insertion. Second premolar abutment interdental alveolar bone resorption was significantly increased as compared to first premolar abutment along the interval periods of the study for Group I. The reverse was observed for Group II. Along the interval periods of the study, the alveolar bone resorption at the first premolar abutment of Group II was significantly increased compared to that of Group I while the reverse was observed when comparing the second premolar of Group I with that of Group II. Compound Aker clasp is better than the multiple circlet clasp assembly as it reduces abutment alveolar bone resorption regards broad stress distribution philosophy is considered for distal extension cases.

  15. Partial dentures as an independent indicator of root caries risk in a group of older adults.

    PubMed

    Steele, J G; Walls, A W; Murray, J J

    1997-01-01

    To estimate the independent association between the wearing of removable partial dentures (RPD) and the presence of root caries in a population of older adults. Multivariate logistic regression modeling of root caries prevalence using different measures of root caries as dependent variables. The model included measures of disease history as indicators of historical risk. Data collected in the field from three areas of England. Random sample of adults aged 60 years and over, drawn from lists of patients registered with general medical practitioners. Field measurements of a range of oral health variables including oral disease, disease history, oral status and various social and demographic measures. The presence of root caries, unsound and sound root restorations. Of the five different models of root caries prevalence which were used, RPDs featured as an independent risk indicator for root surface caries in the three which were related to the presence of untreated disease. The odds ratios for the contribution made by RPDs were all over 1.6, and when considered alone was in excess of 2 in one model. These models were generally well fitting. RPDs did not feature as a risk indicator in the two models which related only to the presence of root surface restorations. In this study, where RPDs were present, the odds of untreated disease being present increased substantially.

  16. Crossover clinical trial of different methods of removing a denture adhesive and the influence on the oral microbiota.

    PubMed

    Nunes, Élen Massaro; Policastro, Vivian Barnabé; Scavassin, Priscila Mattos; Leite, Andressa Rosa Perin; Mendoza Marin, Danny Omar; Giro, Gabriela; de Oliveira Júnior, Norberto Martins; Compagnoni, Marco Antonio; Pero, Ana Carolina

    2016-04-01

    The difficulty of removing denture adhesive is a common problem reported by users of these products. The purpose of this clinical study was to investigate the effectiveness of different cleaning protocols for removing a denture adhesive (DA) and the influence on the oral microbiota. Twenty participants wearing well-fitting complete dentures were instructed to use a denture adhesive 3 times a day during a 4-week trial, divided into 4 stages: (A) control-3 daily denture brushings using water at ambient temperature, (B)-3 daily denture brushings using water at ambient temperature plus coconut soap, (C)-3 daily denture brushings using water at ambient temperature plus dentifrice; (D)-3 daily denture brushings using water at ambient temperature combined with immersion in sodium perborate solution for 5 minutes before nocturnal sleep. After each 1-week stage, saliva specimens were collected. A dye was used to display and quantify the remaining DA on the internal surface of the maxillary dentures as a percentage. For microbiological analysis, the saliva was diluted and plated onto Petri dishes containing a nonselective culture medium and Candida spp culture media. After the incubation period, Candida species were identified and the number of colony forming units (CFU/mL) was calculated. A significant difference was found among the 4 cleaning methods for the quantification of remaining DA (Friedman, P=.036). Brushing the dentures with coconut soap, dentifrice, or water combined with immersion in sodium perborate solution was more effective in removing DA than brushing with only water. The cleaning methods did not influence the quantification of microorganisms in general or Candida albicans and other Candida species in particular. Brushing the dentures with coconut soap, dentifrice, or water combined with immersion in sodium perborate solution was more effective for removing cream-type denture adhesive than brushing with only water. Copyright © 2016 Editorial Council for

  17. Survey of Impression Materials and Techniques in Fixed Partial Dentures among the Practitioners in India

    PubMed Central

    Moldi, Arvind; Puranik, Shivakumar; Karan, Smita; Deshpande, Sumit; Neela, Neelima

    2013-01-01

    Objective. Anecdotal evidence suggests that impression materials and techniques used in general dental practice for fixed partial dentures vary from those taught in dental schools. The aim of this survey was to integrate impression techniques evolved all over the years for fixed partial dentures and to know the techniques and materials which are used in the present day by the practitioners. Materials and Methods. A total of 1000 questionnaires were sent to various practitioners in India, out of which 807 questionnaires were filled. Results. The results showed that 84.8% of prosthodontists (65.56%, urban areas) use elastomeric impression materials as well as irreversible hydrocolloids and 15.2% use irreversible hydrocolloid only. Amongst other practitioners, 55.46% use irreversible hydrocolloid (45%, rural and semiurban areas) and 44.54% use elastomeric impression materials. Elastomeric impression technique practiced most commonly is putty reline with/without spacer (77.2%); other techniques are multiple-mix and monophase techniques. Conclusion. The ideal materials, technique, and armamentarium are required for the long-term success of the treatment for fixed partial denture. Also, if the ideal procedure is not followed, it will lead to a compromised fit of the final prosthesis and failure of the treatment. PMID:23691334

  18. Survey of Impression Materials and Techniques in Fixed Partial Dentures among the Practitioners in India.

    PubMed

    Moldi, Arvind; Gala, Vimal; Puranik, Shivakumar; Karan, Smita; Deshpande, Sumit; Neela, Neelima

    2013-01-01

    Objective. Anecdotal evidence suggests that impression materials and techniques used in general dental practice for fixed partial dentures vary from those taught in dental schools. The aim of this survey was to integrate impression techniques evolved all over the years for fixed partial dentures and to know the techniques and materials which are used in the present day by the practitioners. Materials and Methods. A total of 1000 questionnaires were sent to various practitioners in India, out of which 807 questionnaires were filled. Results. The results showed that 84.8% of prosthodontists (65.56%, urban areas) use elastomeric impression materials as well as irreversible hydrocolloids and 15.2% use irreversible hydrocolloid only. Amongst other practitioners, 55.46% use irreversible hydrocolloid (45%, rural and semiurban areas) and 44.54% use elastomeric impression materials. Elastomeric impression technique practiced most commonly is putty reline with/without spacer (77.2%); other techniques are multiple-mix and monophase techniques. Conclusion. The ideal materials, technique, and armamentarium are required for the long-term success of the treatment for fixed partial denture. Also, if the ideal procedure is not followed, it will lead to a compromised fit of the final prosthesis and failure of the treatment.

  19. Surgical removal of a denture with sharp clasps impacted in the cervicothoracic esophagus: report of three cases.

    PubMed

    Toshima, Takeo; Morita, Masaru; Sadanaga, Noriaki; Yoshida, Rintaro; Yoshinaga, Keiji; Saeki, Hiroshi; Kakeji, Yoshihiro; Maehara, Yoshihiko

    2011-09-01

    We report three cases of successful surgical removal of a denture with sharp clasps impacted in the cervical esophagus. Patient 1 was a 57-year-old woman institutionalized for over 30 years for schizophrenia, patient 2 was a 62-year-old man hospitalized for brain paralysis, and patient 3 was a 64-year-old man suffering cerebral hemorrhage sequelae. All three patients swallowed a denture accidentally. Chest X-rays showed the denture with sharp clasps in the cervicothoracic region of the esophagus, and endoscopy revealed that it was lodged in the esophageal mucosa. The denture was subsequently removed by cervical esophagotomy. All three patients had a good clinical postoperative course without any complications. Thus, we recommend surgery via a cervical approach to remove a denture with sharp clasps impacted in the cervicothoracic esophagus, with intraoperative endoscopic examination for esophageal injury.

  20. Analysis of the effects of removable dentures on the psychological status, quality of life, and masticatory function of the elderly

    NASA Astrophysics Data System (ADS)

    Dyas, R.; Nathanael, M.; Indrasari, M.; Masulili, C.; Rahardjo, T. B.; Agustin, D.; Hogervorst, E.; Kusdhany, L.

    2017-08-01

    Older age is a major risk factor for diseases of the teeth and mouth and dementia. Diseases of the teeth and mouth can lead to tooth loss. The use of removable dentures can help the elderly to replace lost teeth; therefore, dentures are expected to improve the masticatory function, quality of life, and psychological status of the elderly. The aim of this study was to analyze the effects of removable denture usage on the improvement of the psychological status, quality of life, and masticatory function of elderly people. The data was obtained from 30 respondents. The patients answered questionnaires before they used the dentures, 2 weeks after they began using dentures, and 2 months after they started wearing dentures. Four different questionnaires were used: EuroQol Five Dimensions questionnaire (EQ-5D) and Geriatric Depression Scale (GDS), to measure psychological status; a mastication questionnaire to measure masticatory function; and a validated quality of life questionnaire. Based on the results of this study, it is clear that after 2 months of denture usage, removable dentures in the elderly can significantly improve their quality of life, masticatory function, and psychological status(p<0.05).

  1. [The removable partial prosthesis--review of the literature].

    PubMed

    Aeschbacher, A; Brunner, T

    1978-03-01

    Early and late checkups on partial dentures demonstrate clearly, that insufficient cleaning of the remaining dentition and of the prostheses along with an unsatisfactory design are one of the main causes of failures in partial denture therapy. They invariably lead to tissue damages. Hence it has become one of the paramount goals to educate and motivate the patient for adequate mouth and denture hygiene. Also, proper occlusion and the avoidance of parafunction upon the remaining teeth and their supporting tissues must be observed strictly. Therefore, it is important to prepare the remaining dentition carefully and to organize the patients to be recalled for checkups at given intervals. In modern literature on the subject the psychological aspects of difficulties in denture adaptation are more frequently discussed.

  2. Evaluation of a glass-fiber-reinforced, bonded, inlay-supported fixed partial denture--4-year results.

    PubMed

    Jain, Poonam; Cobb, Deborah

    2002-09-01

    Glass-fiber-reinforced composite resin systems may be used as conservative alternatives to conventional fixed partial dentures (FPDs) for the replacement of a single missing tooth. This article describes a clinical technique and 4-year evaluation of an inlay bonded FPD. The patient presented with a missing maxillary right second premolar. A high-caries risk and moderate-to-advanced attachment loss around the abutment teeth, which were clinically stable, were noted. The patient had a strong desire to maintain his remaining dentition. Advantages of supragingival margins and minimal tooth structure removal made the bonded inlay bridge a viable alternative to a conventional FPD for this compromised restorative situation. The clinical performance of this glass-fiber-reinforced resin inlay FPD at the 4-year follow-up is provided. The restoration has served satisfactorily for more than 4 years and holds promise as a conservative, esthetic alternative to the conventional FPD in certain clinical cases.

  3. Denture stomatitis.

    PubMed

    Chen, Amy Yuntzu-Yen; Zirwas, Matthew J

    2007-01-01

    A 70-year-old woman presented for evaluation of an eruption localized to the area covered by her partial upper denture. Her medical history and physical examination were otherwise unremarkable. She originally had a metal upper partial denture, which she used for many years without difficulty. Four years before presentation, she developed a painful eruption affecting only the tissue covered by the upper partial denture. Contact dermatitis to metal was suspected, and a new upper partial denture constructed primarily of acrylates was fashioned. When she transitioned to the new denture, the inflammation in her oral mucosa persisted and perhaps worsened, despite an excellent fit. Examination revealed striking erythema and mild edema sharply localized to the areas where the partial upper denture contacted the gum ridge. Patch testing was performed and revealed allergies to multiple acrylates, including methyl methacrylate. A swab from the gums was sent for yeast culture. No Candida was detected. Based on suspected candidal overgrowth on the denture, the patient was advised to begin applying nystatin ointment between the gums and the denture, and to start soaking the dentures nightly in chlorhexidine 0.12% solution. In addition, because the relevance of the acrylate allergy was unclear, her dentist was contacted and it was recommended that the dentures be boiled to induce polymerization of any residual un-reacted methacrylate monomers. The patient had a 90% improvement in the clinical appearance and in symptoms at an 8-week follow-up appointment. Due to logistic issues, the dentures had not yet been boiled. The improvement, despite the dentures not having been boiled, was felt to demonstrate that the acrylate allergy was not relevant. The patient has continued to slowly show further improvement over 6 months of follow-up.

  4. Evaluation of staining susceptibility of resin artificial teeth and stain removal efficacy of denture cleansers.

    PubMed

    Kurtulmus-Yilmaz, Sevcan; Deniz, Sule Tugba

    2014-11-01

    To assess the staining susceptibility of four acrylic resin (Ivostar, SR Vivodent PE, Major Dent, Integral) and a nanocomposite resin (Veracia) artificial teeth and to evaluate the stain removal efficacy of denture cleansers. Sixty maxillary incisors of each brand (total = 300) were divided into three groups according to staining solution as coffee, red wine and tea. Baseline color measurements were performed with a spectrophotometer. Specimens were immersed in staining solutions for 14 h (2 h × 7 days) and then second color measurements were performed. Each group was further divided into four sub-groups according to denture cleanser as Corega tabs, Fittydent, NaOCl (0.5%) and distilled water (control) (n = 5). Specimens were immersed in denture cleansers for 8 h and third color measurements were made. Thus, the weekly simulation period was completed. This cycle was repeated 12 times to simulate a 3-month time period and measurements were performed at the end of the 4th, 8th and 12th cycles. ΔE values were calculated and data were analyzed with 3-way repeated measures ANOVA and Bonferroni tests. Significant color differences were found among the teeth and staining solutions, but all of the color differences were in the clinically acceptable range (ΔE < 5.5). Integral showed the highest ΔE values for all solutions, while Ivostar and Vivodent demonstrated the lowest ΔE values for red wine and tea solutions. There was no significant difference among the denture cleansers in terms of stain removal efficacy. Cross-linked acrylic (Integral) and nanocomposite (Veracia) resin teeth were more susceptible to staining. Denture cleansers were efficient on stain removal from artificial teeth.

  5. Broncho-Oesophageal Fistula (BOF) Secondary to Missing Partial Denture in an Alcoholic in a Low Resource Country

    PubMed Central

    Odigie, Vincent I.; Yusufu, Lazarus MD.; Abur, Peter; Edaigbini, Sunday A.; Dawotola, David A.; Mai, Ahmad

    2011-01-01

    The clinical course of a missing partial denture with secondary BOF in an alcoholic is presented. In the index case we report an exceptional clinical course of a patient who did not ascribe his symptoms to his ‘‘missing’’ dentures for several years, the odontologist who replaced an unrecovered denture, and the generalist who administered the barium swallow in an unsuspected BOF. Preoperative optimization of the patient was by blenderized local feeds through a feeding tube gastrostomy and by chest physiotherapy. Extraction of the denture and closure of fistula were done through a right thoracotomy. The importance of a high index of clinical suspicion of BOF in a low resource setting to avoid the morbidity and mortality associated with missing dentures is discussed. Odontologists, caregivers and clinicians must educate patients on the hazards of missing dentures and cases of missing / lost dentures should be adequately investigated / explored in the patient’s history and clinical assessment before they are replaced. PMID:22043381

  6. Preimpregnated, fiber-reinforced prostheses. Part I. Basic rationale and complete-coverage and intracoronal fixed partial denture designs.

    PubMed

    Freilich, M A; Duncan, J P; Meiers, J C; Goldberg, A J

    1998-11-01

    This is the first of two articles describing the development and use of a continuous fiber-reinforced composite as a framework for the fabrication of fixed partial dentures and splints. The chemical composition and physical structure of the fiber-reinforced composite, along with the progression and development of a variety of fiber-reinforced composite materials, are discussed. Criteria for case selection, tooth preparation, and the clinical and laboratory procedures required for partial- or complete-coverage fixed partial denture fabrication and delivery are described.

  7. Advanced biomaterials used for a new telescopic retainer for removable dentures.

    PubMed

    Weigl, P; Lauer, H C

    2000-01-01

    Telescopic retainers with conical ceramic abutment crowns and electroplated gold copings define a new retainer for removable dentures exhibiting favorable tribological properties that could offer clinical advantages. The objective of this study was to evaluate the clinical effects of this retainer. To do so, a novel treatment modality was developed based on intraoral bonding of the copings to the framework in order to be able to realize, in a clinical setting, the retainer function based on a precision fit. A total of 32 patients wearing 33 dentures (16 mandibular, 17 maxillary; period of risk [months]: minimum = 3; maximum = 58; mean = 27.6), supported by 147 abutments (83 natural teeth, 64 implants) with ceramic abutment crowns (IPS Empress 1, IPS Empress 2, InCeram, Procera, CerAdapt; CeraBase) were followed at 6-month intervals. The ceramic abutment crowns showed low plaque accumulation (mean PI = 17.3%). The gingival tissues around natural abutments were generally free of inflammation; so was the mucosa around the implants (mean SBI = 4.9%). Denture adhesion and occlusion did not change, and there were no rocking movements. The mobility (as determined by Periotest) of 29 teeth was reduced in a highly significant manner within 6 months (t test, p < 0.001). Osseointegration was preserved for all implants. One abutment loosened. Six Empress 1 ceramic copings failed (94.6% Kaplan-Meier survival rate), and one abutment tooth was lost (99.2% survival rate). All patients reported problem-free handling, no rocking movements, and constant adhesion. The adhesive strength of one denture was too low at insertion. 94% of the patients experienced no problems with oral hygiene. The retainer examined has relevant clinical advantages and meets geriatric requirements for removable dentures. Copyright 2000 John Wiley & Sons, Inc.

  8. The method of manufacture of nylon dental partially removable prosthesis using additive technologies

    NASA Astrophysics Data System (ADS)

    Kashapov, R. N.; Korobkina, A. I.; Platonov, E. V.; Saleeva, G. T.

    2014-12-01

    The article is devoted to the topic of creating new methods of dental prosthesis. The aim of this work is to investigate the possibility of using additive technology to create nylon prosthesis. As a result of experimental studies, was made a sample of nylon partially removable prosthesis using 3D printing has allowed to simplify, accelerate and reduce the coat of manufacturing high-precision nylon dentures.

  9. Release of chlorhexidine digluconate and flexural properties of glass fibre reinforced provisional fixed partial denture polymer.

    PubMed

    Lahdenperä, Milla S; Puska, Mervi A; Alander, Pasi M; Waltimo, Tuomas; Vallittu, Pekka K

    2004-12-01

    The objective of this study was to determine the flexural properties and the release of chlorhexidine digluconate (CHX) of CHX laced unidirectional E-glass fibre reinforced provisional fixed partial denture polymer. Bar shaped test specimens (3.3 x 10.0 x 65.0 mm) were fabricated from provisional fixed partial denture polymer (mixture of poly[ethylmethacrylate] powder and n-poly[butyl methacrylate] monomer liquid) with E-glass fibre reinforcements. Poly(methyl methacrylate) preimpregnated continuous unidirectional glass fibre reinforcement was laced with CHX. The glass fibre reinforcements were incorporated into the polymer and the polymerised to the form of test specimens. In addition test specimens without CHX in glass fibre reinforcement were made for comparison. Control specimens did not contain glass fibres in the test specimens. Flexural strength and modulus of test specimens (n = 6) was tested with three-point bending test after storing the specimens dry or in water (two weeks). Released CHX was determined with high performance liquid chromatography during 180 days water immersion. In dry conditions, the flexural strength and the modulus of the polymer was 43 MPa and 1.7 GPa, and with glass fibre reinforcement 96 MPa and 3.5 GPa. With the reinforcement laced with CHX, the strength was 92 MPa and the modulus was 3.2 GPa. The water storage of test specimens did not weaken the reinforced polymer. The majority of the CHX released from the glass fibre reinforced polymer during the first days of storage in water. Flexural properties of provisional fixed partial denture polymer were increased using glass fibre reinforcement. The fibre reinforcement that was laced with CHX resulted in similar reinforcing effect.

  10. Prognosis of zirconia ceramic fixed partial dentures: a 7-year prospective study.

    PubMed

    Lops, Diego; Mosca, Daniela; Casentini, Paolo; Ghisolfi, Marco; Romeo, Eugenio

    2012-01-01

    The aim of this study was to evaluate the time-dependent clinical efficacy of anterior and posterior zirconia fixed partial dentures (FPDs). A convenience sample of 28 patients, each wearing 1 FPD, was recalled annually throughout a 6-year follow-up period (mean: 6.5 years). Four patients did not participate in the study (dropouts), and 24 FPDs were in use during the observation period. The cumulative survival and success rates were 88.9% and 81.8%, respectively. Fixed prostheses with zirconia frameworks may be regarded as acceptable alternatives to metal-ceramic anterior and posterior FPDs.

  11. Adhesion monomers utilized for fixed partial denture (porcelain/metal) repair.

    PubMed

    Bertolotti, R L; Paganetti, C

    1990-07-01

    A technique is presented for repair of fatigue-fractured fixed partial dentures with an overlaid, bonded porcelain/metal repair. The repair techniques utilize recent advances in resin-to-metal and resin-to-porcelain adhesion. Clinical procedures are given for adhesion of repair castings to intraoral porcelain or metal surfaces. Metal surface preparation techniques depend on the chemistry of the metal and include intraoral tin plating of noble metals. Direct adhesion of composite resin luting agents is used for base metals.

  12. The effects of remelting on the mechanical properties of a nickel base partial denture casting alloy.

    PubMed

    Lewis, A J

    1975-04-01

    Three series of tensile test pieces were produced using a nickel base partial denture casting alloy. For the first series induction heating was employed, for the second a resistance crucible, and for the third, an oxy-acetylene torch. In each series the same metal was cast sequentially a number of times and all test pieces so produced were subjected to mechanical testing. The mechanical properties were found to vary according to both the number of times the alloy was cast and the method of heating used to render the alloy molten.

  13. Mycological Analysis of the Oral Cavity of Patients Using Acrylic Removable Dentures

    PubMed Central

    Loster, Bartłomiej W.; Loster, Jolanta; Wieczorek, Aneta; Ryniewicz, Wojciech

    2012-01-01

    Background. The problems of fungal infections in edentulous have been discussed in literature. Findings show that oral mycosis has an influence on the mycosis of oesophageal mucosa. Based on this we started to follow from 2007 in patients who wear dentures mycological examination, to evaluate changes of yeasts numbers, the sensitivity to antibiotics and determine the impact of types of prosthesis, time of using, gender and age of patients. 1230 patients who were wearing dentures participated in the retrospective study. The material for mycological examination was sampled as a smear from the palate. After the mycological identification of Candida species and assessment of growth, the susceptibility testing with Fluconazole and Nystatin was made. The number of 23 Candida species was diagnosed microbiologically in five years. C. albicans and C. glabrata were increasing in number—from 33,7% to 46,9% and 6,7% to 14,0%, respectively. There was a significant statistical difference between yeasts growth and gender (P = 0, 017 < 0.05). The conclusion is that a large percentage of persons wearing removable denture has been affected by Candida species and that could lead to the mycosis of farther gastrointestinal tract sections. The mycological examination before treatment, especially in patients using acrylic denture, appears to be necessary. PMID:22550480

  14. Sectional dentures revisited.

    PubMed

    Karir, Naveen; Hindocha, Vishali; Walmsley, A Damien

    2012-04-01

    Sectional dentures are constructed in separate parts which join together intra-orally to create a single prosthesis. They are used to exploit undercuts around teeth, hard and soft tissues which require more than one path of insertion, and are usually of split pin or locking bolts design. By using two case studies, we aim to illustrate the provision of sectional dentures and to which situations their uses are best suited. A 30-year-old male was referred to the Department of Prosthetics at the Birmingham Dental Hospital for a replacement upper partial cobalt chrome denture of a Kennedy Class IV bounded saddle. The patient had a history of failed upper cobalt chrome removable partial dentures owing to loss of retention and poor stability over the previous 12 months. A 40-year-old female patient was referred by her GDP for restoration of a bounded saddle in the lower right quadrant with a history of intolerance to previous dentures. These two cases demonstrate the successful use of sectional dentures in the aesthetic zone. Although more technically demanding, they lie well within the scope of general practice and offer patients alternative solutions from dental implants and bridgework. These cases highlight the importance of the use of alternative prosthetic techniques which can be simple and achievable for all practitioners. Sectional dentures are a treatment modality for the edentulous space where the presence of one or more undercuts prevents restoration by more conventional techniques. This paper highlights some of the situations in which sectional dentures can be employed and emphasizes their use in general practice.

  15. Microspectral analysis with laser in microleakage evaluation between infrastructure and veneer materials in fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda L.; Sinescu, Cosmin; Draganescu, Gheorghe; Todea, Carmen; Dodenciu, Dorin; Rominu, Roxana

    2008-02-01

    The microleakage at the interface between the metal infrastructure and the veneering part of the fixed partial dentures are a common problem of aesthetic dentistry. It is possible to use the method of laser microspectral analysis for investigations of microleakage at the metal-veneering material interfaces in fixed partial prostheses. The laser microspectral analysis device LMA-10 (Carl Zeiss, Jena) was used equipped with a diffraction spectrometer PGS-2 (Carl Zeiss, Jena). Different fixed partial dentures were used to determine the microleakage between the metal infrastructure and the veneering material. The distribution of chemical elements at interface infiltration was investigated, making a series of craters and establishing the spectra of the vapours emitted from the craters. Data was gathered in various tables of chemical elements showing the quality and the quantity of microleakage. The laser microspectral analysis is a punctual method of analysis, which allows to investigate small quantities of materials of around 0.1 μg. This method allows to establish the content of atoms and molecules and to perform semi-quantitative and quantitative analysis. By this method it is possible to establish trace elements, i. e. with concentration of ppm (parts per million).

  16. Resin-bonded, glass fiber-reinforced composite fixed partial dentures: a clinical study.

    PubMed

    Vallittu, P K; Sevelius, C

    2000-10-01

    Resin-bonded, glass fiber-reinforced composite fixed partial dentures (FPDs) have been under development for some time. There is a lack of data regarding the clinical usefulness of such prostheses. The clinical performance of 31 resin-bonded, glass fiber-reinforced composite fixed partial dentures was evaluated in a preliminary study. The prostheses were made to replace 1 to 3 missing maxillary or mandibular teeth in each of 31 patients. The prostheses had a framework made of continuous unidirectional E-glass fibers with multiphase polymer matrix and light-polymerized particulate composite resin veneering. The prostheses were examined after 6-month periods for up to 24 months (mean follow-up time was 14 months). Partial or total debonding of the prostheses or the framework fracture was considered a treatment failure. Two prostheses debonded during the follow-up period; 1 debonding was related to improper occlusal adjustment and the other to unknown reasons. Kaplan-Meier survival probability at 24 months was 93%. No framework fractures were observed. The results of this preliminary study suggest that the resin-bonded, glass fiber-reinforced FPDs may be an alternative for resin-bonded FPDs with a cast metal framework.

  17. Survey on use of titanium dentures in Tsurumi University Dental Hospital for 11 years.

    PubMed

    Takayama, Yasuko; Takishin, Norio; Tsuchida, Fujio; Hosoi, Toshio

    2009-04-01

    The purpose of this study was to survey the production of titanium dentures in Tsurumi University Dental Hospital and to study the actual use of titanium dentures in our university. The survey was based on the metal base dentures produced at Tsurumi University Dental Hospital during an 11-year period between April 1995 and March 2006, with relation to the types of metals used in the dentures, types of dentures, dental condition, and the number of artificial teeth. 1871 metal base dentures were produced in the study period. The dentures consisted of 1290 cobalt-chromium alloy dentures (68.9%), 350 titanium dentures (18.7%) and 231 platinum-added gold alloy dentures (12.3%). Within the titanium denture groups, 132 were complete dentures (37.7%), 55 were complete overdentures (15.7%) and 163 were removable partial dentures (46.6%). JIS type 3 pure titanium was used in the titanium base of 252 dentures (72.0%). The average number of artificial teeth was 10.9, which was the highest among the three types of metal bases, exhibiting significant differences (P<0.01). Approximately 32 titanium dentures per year on average were delivered at our university and they were applied to almost edentulous arch compared with the other metal base dentures.

  18. Oral Crest Lengthening for Increasing Removable Denture Retention by Means of CO2 Laser

    PubMed Central

    Nammour, Samir; Gerges, Elie; Bou Tayeh, Rima; Zeinoun, Toni

    2014-01-01

    The loss of teeth and their replacement by artificial denture is associated with many problems. The denture needs a certain amount of ridge height to give it retention and a long-term function. Crest lengthening procedures are performed to provide a better anatomic environment and to create proper supporting structures for more stability and retention of the denture. The purpose of our study is to describe and evaluate the effectiveness of CO2 laser-assisted surgery in patients treated for crest lengthening (vestibular deepening). There have been various surgical techniques described in order to restore alveolar ridge height by pushing muscles attaching of the jaws. Most of these techniques cause postoperative complications such as edemas, hemorrhage, pain, infection, slow healing, and rebound to initial position. Our clinical study describes the treatment planning and clinical steps for the crest lengthening with the use of CO2 laser beam (6–15 Watts in noncontact, energy density range: 84.92–212.31 J/cm2, focus, and continuous mode with a focal point diameter of 0.3 mm). At the end of each surgery, dentures were temporarily relined with a soft material. Patients were asked to mandatorily wear their relined denture for a minimum of 4–6 weeks and to remove it for hygienic purposes. At the end of each surgery, the deepest length of the vestibule was measured by the operator. No sutures were made and bloodless wounds healed in second intention without grafts. Results pointed out the efficiency of the procedure using CO2 laser. At 8 weeks of post-op, the mean of crest lengthening was stable without rebound. Only a loss of 15% was noticed. To conclude, the use of CO2 laser is an effective option for crest lengthening. PMID:25383385

  19. Effect of framework design on fracture resistance of zirconium oxide posterior fixed partial dentures

    PubMed Central

    Salimi, Hadi; Mosharraf, Ramin; Savabi, Omid

    2012-01-01

    Introduction: The effect of framework design modifications in all-ceramic systems is not fully understood. The aim of this investigation was to evaluate the effect of different framework designs on fracture resistance of zirconium oxide posterior fixed partial dentures (FPD). Materials and Methods: Thirty two posterior zirconia FPD cores were manufactured to replace a second premolar. The specimens were divided into four groups; I: 3 × 3 connector and standard design, II: 3 × 3 connector and modified design, III: 4 × 4 connector dimension, and standard design and IV: 4 × 4 connector dimension and modified design. After storing for one week in artificial saliva and thermocycling (2000 cycles, 5-55°C), the specimens were loaded in a universal testing machine at a constant cross-head speed of 0.5 mm/min until failure occurred. The Weibull, Kruskal-Wallis, and Mann-Whitney tests were used for statistical analysis (α = 0.05). Results: The mean fracture resistance of groups with 4 × 4 mm connector was significantly higher than groups with 3 × 3 mm connector (P < 0.001). Although, the fracture resistance of the modified frameworks was increased in the present study (1.1 times), they were not significantly different from anatomic specimens (P = 0.327). Conclusions: The fracture resistance of the zirconia posterior-fixed partial dentures was significantly affected by the connector size; it was not affected by the framework modification. PMID:23559956

  20. Influence of framework design, contraction mismatch, and thermal history on porcelain checking in fixed partial dentures.

    PubMed

    Anusavice, K J; Gray, A E

    1989-01-01

    The objective of this study was to characterize the relative influence of contraction mismatch, framework design, furnace type, cooling rate, and multiple firings on immediate or delayed checking in fixed partial dentures. Frameworks for 60 anterior bridges (three-unit fixed partial dentures) were cast from a low-expansion Au-Pd alloy (O) and a high-expansion Pd-Ag alloy (J). A high-expansion porcelain (B) was applied to each of three framework designs. Firing was performed at heating rates of 56 degrees C/min and 180 degrees C/min. Specimens were cooled at two rates after each of five glazing cycles. For O-B specimens which exhibited a negative thermal contraction mismatch between 600 degrees C and 25 degrees C, 60% of the bridge specimens failed when they were subjected to slow cooling preceded by either fast or slow heating. When J-B specimens (which exhibited a smaller negative contraction mismatch) were heated and cooled rapidly, no failures occurred through all of the firing cycles. However, cracks were observed in 13.3% of the J-B bridges which were slowly heated and rapidly cooled. Delayed cracks (after the fifth glaze cycle) developed over periods of up to two years only in bridges which were slowly cooled in the furnace chamber. The results of this study suggest that checking in conventional feldspathic porcelains can be promoted by slow cooling rates and an excessive number of firing cycles.

  1. Use of aluminum strips to fabricate verification jig for an implant-supported fixed partial denture.

    PubMed

    Papazian, S; Morgano, S M

    1998-03-01

    Verification of the accuracy of the master cast for an implant-supported fixed partial denture will reduce the chair time and laboratory costs of implant prosthodontic treatment. A wire is usually luted in the mouth to machined components that have been secured to the implants, and the luted assembly is then transferred to the cast to evaluate the positional accuracy of the implant analogs. Unless this wire is dead soft, inaccuracies as a result of elastic memory of the wire can occur. Also, if the wire is not completely rigid, it can be distorted during handling. This article describes a more reliable verification jig for an implant-supported fixed partial denture that can be fabricated with 1.5 mm thick aluminum strips that are luted to the implant components. The use of two aluminum strips creates a metal framework that is rigid and not easily distorted. Also the aluminum pieces do not have elastic memory because they were cut and not bent to shape.

  2. Three-year clinical evaluation of fiber-reinforced composite fixed partial dentures using prefabricated pontics.

    PubMed

    Unlu, Nimet; Belli, Sema

    2006-06-01

    The purpose of this study was to evaluate the clinical performance of surface-retained adhesive composite fixed partial dentures reinforced by an ultra-high molecular weight polyethylene (UHMWP) fiber (Ribbond THM). Twenty-three surface-retained fiber reinforced composite (FRC) fixed partial dentures (FPD) were placed by two operators in 23 patients, each with a single missing tooth. The restorations included prefabricated composite resin pontics, and no preparations were done on the lingual surfaces of the abutment teeth. The patients were recalled for examinations every year for up to 3 years. Restorations were evaluated directly using the modified Ryge criteria. The minimum observation period was 1 year and the maximum observation period was 3 years. At baseline, 23 restorations were graded as Alpha for all parameters. At one year and two years (n = 21), three Bravos for wear resistance and surface texture/gingival inflammation and two Bravos for color match were observed. Twenty-one of 23 restorations were retained at the end of two years (91.3%) and 78.3% were retained after a maximum of 3 years. The results of this clinical study suggestthat UHMWP FRC FPDs are quite acceptable at least forthree years. However, further clinical investigations are still needed for improved long-term clinical performance.

  3. Removable partial overdentures for the irradiated patient

    SciTech Connect

    Rosenberg, S.W. )

    1990-10-01

    Patients who have received radiotherapy to the head and neck area must avoid dental extractions and seek simplicity in treatment and home care follow-up. For partially edentulous patients, removable partial overdenture therapy can fulfill these goals while maintaining the high level of function and aesthetics desired by patients.11 references.

  4. Semiprecision rest system for distal-extension removable partial dentures.

    PubMed

    Zinner, I D

    1979-07-01

    The history of the nonlocking type of intracoronal semiprecision rest has been traced from its origins with Neurohr in 1930, up to its present use as the Thompson dowel rest. The advantages of the use of this deep rest design and the clasp arm design for primary retention have been discussed. The Blatterfein modification of the lingual clasp arm has been introduced to overcome the problems of breakage and lack of stabilization which are present with the Thompson, Van Dam, and Wands designs.

  5. Relationships between facial morphology and activity of orofacial muscles in patients with a complete upper and a partial lower denture.

    PubMed

    Tallgren, A; Tryde, G

    1995-08-01

    In a sample of 30 partially edentulous subjects, provided with an immediate complete upper denture and a partial lower denture and followed for 2 years, a correlation analysis was performed between facial morphology, as measured by lateral head films, and EMG peak mean voltages of the anterior temporal and masseter muscles when clenched and during swallowing and chewing, and of the lip muscles during swallowing. At the pre-treatment stage, when the patients occluded on a residual anterior dentition, correlations between facial morphologic characteristics and peak mean voltages of the jaw closing muscles indicated stronger muscle activity in individuals with a square facial type. No significant associations were observed between muscle activity and the age of the subjects, which ranged from 36 to 71 years. After placement and use of the dentures a significant forward-upward rotation of the mandible with a decrease in overbite occurred, as a result of resorption of the edentulous maxillary ridge. At the 1 year stage of denture use, the elevator activity showed no significant correlations with facial morphology. On the other hand, negative correlations were observed especially between the anterior temporal activity and anterior overbite. Similar negative correlations were observed for the lip activity during swallowing, especially of the upper lip. These findings suggest occlusal contact between the incisors during the various functions in subjects with a small overbite. The findings further suggest that the anterior temporal and the upper lip muscles are sensitive to changes in anterior occlusal relations of the dentures.

  6. Cu-sil dentures – a novel approach to conserve few remaining teeth: Case reports

    PubMed Central

    Jain, Jayesh Kumar; Prabhu, C R Allama; Zahrane, Mohammed Al; Esawy, Mohammed Sayed Al; Ajagannanavar, Sunil Lingaraj; Pal, Kapil Singh

    2015-01-01

    The present prime concern in dentistry is on preservation of remaining natural teeth. Presence of few teeth in oral cavity help in preserving alveolar ridge integrity, maintain the proprioception, and gives psychological benefit to the patient. Transitional denture provides us with alternative treatment plan for the patients willing to replace their missing teeth while retaining their very few remaining teeth. A relatively newer type of transitional denture is Cu-sil denture. A Cu-sil denture is a denture with holes, lined by a gasket of silicone rubber, the holes thus providing space for remaining natural teeth to emerge into the oral cavity through the denture. Cu-sil denture is the simplest removable partial denture, but its fabrication requires special armamentarium and material. This case report represents a simple chairside technique to fabricate Cu-sil dentures in usual dental set-up. PMID:26464557

  7. [Clinical application of anterior all-ceramic cantilevered resin-bonded fixed partial dentures].

    PubMed

    Zhang, Lei; Nie, Yu-Guang; Xie, Qiu-Fei

    2008-04-01

    To explore a fabricating method of incisor all-ceramic cantilevered resin-bonded fixed partial denture (RBFPD) and evaluate their clinical performances. All-ceramic cantilevered RBFPDs were made to replace 1 missing incisor in each of 10 patients. The RBFPDs with lingual surface retainer were made of Empress II ceramic materials and luted with resin cement. The prostheses were examined at 2 weeks, 1 year and 2 years after denture insertion. Examining criteria included: fracture of bridge, marginal adaptation, secondary caries, and color match. The average follow-up period was 14. 7 months. No framework fracture and retainer debonding were observed and marginal adaptation was evaluated as good. Seven RBFPDs matched the color of adjacent teeth, and other three did not match well but within the acceptable range of tooth shade difference. The results of this preliminary study suggest that the clinical performances of all-ceramic cantilevered RBFPDs are good in short-term evaluation, but their long-term success needs to be further investigated.

  8. The teaching of fixed partial dentures in undergraduate dental schools in Ireland and the United Kingdom.

    PubMed

    Lynch, C D; Singhrao, H; Addy, L D; Gilmour, A S M

    2010-12-01

    All areas of the practice of dentistry are evolving at a considerable pace. One area in particular which has seen a rapid revolution is the oral rehabilitation of partially dentate adults. The aim of this study was to describe the contemporary teaching of fixed partial dentures (FPDs) in dental schools in Ireland and the United Kingdom. An online questionnaire which sought information in relation to the current teaching of FPDs was developed and distributed to 15 Irish and UK dental schools with undergraduate teaching programmes in Spring 2009. Responses were received from 12 schools (response rate=80%). All schools offer teaching programmes in relation to FPDs. The number of hours devoted to pre-clinical/phantom head teaching of FPDs ranged from 3 to 42h (mean: 16h). The staff/student ratio for pre-clinical teaching courses in FPDs ranged from 1:6 to 1:18 (mode: 1:12). Cantilever resin-retained FPDs were the most popular type of FPD provided clinically (average=0·83 per school; range=1-2). Five schools (42%) report that they have requirements (e.g. targets, quotas, competencies) which students must complete prior to graduation in relation to FPDs. Fixed partial dentures form an important part of the undergraduate teaching programme in UK and Irish dental schools. While this teaching is subjected to contemporary pressures such as lack of curriculum time and a lack of available clinical facilities and teachers, there is evidence that teaching programmes in this area are evolving and are sensitive to current clinical practice trends and evidence-based practice.

  9. The all-ceramic, inlay supported fixed partial denture. Part 4. Fracture surface analyses of an experimental model, all-ceramic, inlay supported fixed partial denture.

    PubMed

    Thompson, M C; Sornsuwan, T; Swain, M V

    2013-06-01

    In the previous three papers, the authors sought to conduct a thorough analysis of the feasibility for the use of zirconia in inlay supported, fixed partial dentures via finite element analysis (FEA). Correlating the response of the numerical model against the experimental model has never been satisfactorily performed for an anatomically accurate ceramic bridge; such validation is crucial if the results from the FEA are to be confidently relied upon. Part 4 of this series is a detailed fractographic analysis of the zirconia bridge that was the model for the experimental validation, performed in order to confirm the fracture origin/s and fracture trajectory as predicted from the FEA. Established fractographic techniques involving optical examination followed by examination with scanning electron microscopy were conducted. The porous, granular surface of zirconia (both partially and fully sintered) does not lend itself to easy surface analysis but the classic fractographic signs (hackle lines, wake hackle lines and compression curl) are present. Use of linear fracture elastic mechanics allowed the calculation of theoretical critical flaw size and a comparison to two defects or inclusions found at the primary origin of fracture. Excellent agreement between the fracture sites and paths of travel as predicted in the numerical analysis exist with fractographic analysis. Furthermore, the calculated critical flaw size of 30 μm to 40 μm equates very well with defects seen at the general vicinity of the primary fracture origin and the general observed size of critical flaws in machined ceramics which range between 20 μm to 50 μm, thus providing further confirmation. The fractographic analysis detailed in this study provides validation of the 'zones of failure' as predicted in our FEA. Additionally, the excellent correlation between the calculated critical flaw size and the defects observed at the primary fracture site demonstrates that field of experimental mechanics is

  10. Evaluating the efficiency of humic acid to remove micro-organisms from denture base material.

    PubMed

    Meriç, Gökçe; Güvenir, Meryem; Süer, Kaya

    2016-09-01

    To evaluate the efficiency of humic acid substances on removing micro-organisms from denture base materials. Old denture wearer needs effective, easy-use and safe denture-cleaning material. Square-shaped, heat-polymerised acrylic resin specimens (n = 550) were prepared and divided into five groups (n = 110 for each) corresponding to the microbial contamination (Candida albicans, Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Pseudomonas aeruginosa). Contaminated specimens were randomly assigned to the application of five different denture-cleaning agents as follows (n = 20 for each): Kloroben, Corsodyl, Steradent, Corega, experimental solution with humic acid. Ten specimens were assessed as an experimental control carried out simultaneously for the treatment groups for each micro-organism. It was divided into two groups: negative control and positive control (n = 5 for each). All acrylic specimens were incubated 37°C for 24 h (for bacterial strains) and 37°C for 48 h (for yeast strains). After incubation period, all brain-heart infusion broths (BHI) which contain disinfectant acrylic specimens were cultured on 5% sheep blood agar (for bacteria) and Sabouraud dextrose agar (SDA) for yeast using loop. The numbers of colony-forming units per millilitre (CFU/ml) were calculated. The results were analysed by Mann-Whitney U-test and Kruskal-Wallis tests (p = 0.05). Corsodyl and Kloroben completely eliminated the adherence of all investigated micro-organisms (100%) and showed the highest removal activity compared with other cleaning agents (p < 0.05). There was no statistically significant difference between Corsodyl and Kloroben (p ≥ 0.05), and there was no statistically significant difference between Corega, Steradent and experimental solution (p ≥ 0.05). Humic acid could be used as an alternative 'natural' solution for denture-cleaning agent. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley

  11. Preoperative intraoral evaluation of planned fixed partial denture pontics using silicone putty.

    PubMed

    Mysore, Ashwin Raghunandan; Aras, Meena Ajay

    2013-06-01

    A preoperative visualization and evaluation of fixed partial denture (FPD) pontics in the anterior dentition is necessary for both the patient and the dentist. Such an evaluation allows patients to decide whether the esthetic and functional parameters of the restoration meet their requirements and expectations. To facilitate such an assessment, a method that allows stable intraoral positioning of the pontics is required. This article describes a technique to achieve this in a simple and effective way before the abutments are prepared. In addition, it also allows the operator to modify the pontics intraorally for esthetics and later incorporate the same pontics into the interim prosthesis. The integration of this pretreatment pontic evaluation procedure into FPD restorations assures better results and patient satisfaction.

  12. Clinical morbidity and sequelae of treatment with complete dentures.

    PubMed

    Carlsson, G E

    1998-01-01

    Wearing complete dentures may have adverse effects on the health of both the oral and the denture-supporting tissues. This article is a review of selected literature on the sequelae of treatment with complete dentures in the specific areas of residual ridge resorption, mucosal reactions, burning mouth syndrome, temporomandibular disorders, and patient satisfaction. Recent literature found with a Medline search from 1952 to 1996 is included in this review. Residual ridge resorption is an inevitable consequence of tooth loss and denture wearing, with no dominant causative factor having been found. Mucosal reactions have a multifactorial cause, most of which can be easily treated. Most patients are satisfied with their complete dentures. Correlations between anatomic conditions and denture quality and patient satisfaction are weak. Psychologic factors seem to be extremely important in the acceptance of and adaptation to removable dentures. There are still no reliable methods to predict the outcome of complete denture treatment and there are many problems related to treatment with complete dentures. Although the prevalence of an edentulous condition is decreasing, the great number of edentulous people warrants the continuing efforts of basic and clinical research on removable partial dentures. Complete denture prosthodontics will remain an important part of dental education and practice. In addition to clinical and technical skills, insight into patient behavior and psychology and communication techniques are also necessary.

  13. Fixed partial dentures in an up to 8-year follow-up

    PubMed Central

    CENCI, Maximiliano Sérgio; RODOLPHO, Paulo Antônio da Rosa; PEREIRA-CENCI, Tatiana; CURY, Altair Antoninha Del Bel; DEMARCO, Flávio Fernando

    2010-01-01

    Information on the longevity of fiber-reinforced composite fixed partial dentures (inlay FPDs) should be considered in the selection of materials, operative techniques and patient instructions related to prognosis and long-term cost-effectiveness. Objective This study evaluated the long-term survival of fiber-reinforced, adhesively-bonded composite prostheses placed in posterior teeth. Material and Methods Twenty-one patients that received adhesively bonded polyethylene inlay FPDs in posterior teeth were selected from a private practice dental office and invited to evaluation. Of the eligible 21 patients, 13 (mean age 50.3 ±11.5 years) agreed to be enrolled as participants, providing 22 restorations, as several subjects presented more than one inlay FPD. One dentist placed all inlay FPDs using Ribbond as reinforcement and Tetric Ceram/Durafil or Charisma/Renamel composite combinations, according to manufacturer’s instructions. Two independent calibrated operators performed the evaluation, using modified USPHS criteria. Survival functions of restorations were analyzed with Kaplan-Meier and Log Rank test (α = 0.05). Results The majority of restorations received A or B scores. Four (18.2%) inlay FPDs fractured among the 22 evaluated. The mean estimate survival rate was 7 years (95% CI: 5.9 to 8.1), and the overall percentage of survival was 81.8%. There were no significant differences (p>0.05) between composite combinations or tooth location considering all clinical aspects evaluated and survival functions. Conclusion Posterior fiber-reinforced fixed partial dentures exhibited acceptable clinical performance after a period up to 8 years. PMID:20835571

  14. [Problems of incorporation of removable dentures with special reference to psychosomatic changes due to aging].

    PubMed

    Breustedt, A

    1978-01-01

    The successful use of technically unobjectionable plate dentures is a very complicated process that depends upon the patient's psychic attitude towards the removable prosthesis, the motivation, the ability of the sensory terminal organs in the oral cavity to get accustomed to the foreign body (the prosthesis), the adaptation and the learning of new sequences of reflex movements as a motor-muscular performance of perfection. These three factors, which the author regards as essential prerequisites of the incorporation (i. e., the untroubled mechanical use of the prostheses), are interpreted in the light of clinical experience and opinions from the most recent literature.

  15. Alternative complete-arch cement-retained implant-supported fixed partial denture.

    PubMed

    Hofstede, T M; Ercoli, C; Hagan, M E

    1999-07-01

    Early implant prostheses designs, which used screw-retained metal and acrylic resin structures, frequently left a space between the prosthesis and the soft tissue. Common deficiencies of this design included phonetic and esthetic problems and screw loosening. Cement-retained implant prostheses are also used in partially and completely edentulous patients, and are thought to have optimal occlusion and esthetics. Moreover, cement-retained prostheses may induce less stress on the implant, thereby maximizing the possibility of a passive fit. Porcelain fused to metal prostheses have been used mostly in partially edentulous situations. Recently, complete-arch porcelain fused to metal prostheses that replace hard and soft tissue have been used and, although this restoration can have excellent esthetics, there are disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures of in-service porcelain. This article describes an alternative technique for the fabrication of a complete-arch, cement-retained, metal-acrylic resin implant-supported fixed partial denture. When compared with porcelain fused to metal complete-arch restorations, this prostheses is esthetic, has excellent retention and stability, yet is relatively inexpensive to fabricate, and requires less laboratory skill.

  16. Multiple Logistic Regression Analysis of Risk Factors Associated with Denture Plaque and Staining in Chinese Removable Denture Wearers over 40 Years Old in Xi’an – a Cross-Sectional Study

    PubMed Central

    Chai, Zhiguo; Chen, Jihua; Zhang, Shaofeng

    2014-01-01

    Background Removable dentures are subject to plaque and/or staining problems. Denture hygiene habits and risk factors differ among countries and regions. The aims of this study were to assess hygiene habits and denture plaque and staining risk factors in Chinese removable denture wearers aged >40 years in Xi’an through multiple logistic regression analysis (MLRA). Methods Questionnaires were administered to 222 patients whose removable dentures were examined clinically to assess wear status and levels of plaque and staining. Univariate analyses were performed to identify potential risk factors for denture plaque/staining. MLRA was performed to identify significant risk factors. Results Brushing (77.93%) was the most prevalent cleaning method in the present study. Only 16.4% of patients regularly used commercial cleansers. Most (81.08%) patients removed their dentures overnight. MLRA indicated that potential risk factors for denture plaque were the duration of denture use (reference, ≤0.5 years; 2.1–5 years: OR = 4.155, P = 0.001; >5 years: OR = 7.238, P<0.001) and cleaning method (reference, chemical cleanser; running water: OR = 7.081, P = 0.010; brushing: OR = 3.567, P = 0.005). Potential risk factors for denture staining were female gender (OR = 0.377, P = 0.013), smoking (OR = 5.471, P = 0.031), tea consumption (OR = 3.957, P = 0.002), denture scratching (OR = 4.557, P = 0.036), duration of denture use (reference, ≤0.5 years; 2.1–5 years: OR = 7.899, P = 0.001; >5 years: OR = 27.226, P<0.001), and cleaning method (reference, chemical cleanser; running water: OR = 29.184, P<0.001; brushing: OR = 4.236, P = 0.007). Conclusion Denture hygiene habits need further improvement. An understanding of the risk factors for denture plaque and staining may provide the basis for preventive efforts. PMID:24498369

  17. A clinical overview of removable prostheses: 5. Diagnosis and treatment of RPD problems.

    PubMed

    McCord, J Fraser; Grey, Nick J A; Winstanley, Raymond B; Johnson, Anthony

    2003-03-01

    This, the fifth and final article in the series, addresses the diagnoses and treatment of problems which may arise following provision of removable partial dentures (RPDs). These include difficulties seating the denture, pain and discomfort, looseness and functional problems.

  18. Combination PROP: A Case Report of a Hybrid Flexible and Traditional Partial Removable Dental Prosthesis.

    PubMed

    Umsted, David E; Ragain, James C; Wicks, Russell A

    2015-01-01

    The need for partial removable dental prostheses (PRDP) is increasing as the over-65 partially edentulous population grows. The use of flexible materials in the fabrication of these prostheses has captured a large portion of the market once occupied by traditional cast metal PRDPs. While there are some clinical advantages to the use of flexible PRDPs, there are also disadvantages and contraindications that must be considered. This paper describes a clinical case in which a patient's dentition is restored with a hybrid partial removable dental prosthesis consisting of a traditional metal framework and flexible denture base and clasps. This design can result in achieving the benefits of each type of prosthesis in an effort to satisfy the needs of the patient.

  19. Implant-connected versus tooth-connected implant-supported partial dentures: 2-year clinical and radiographic comparative evaluation.

    PubMed

    Mostafa, Tamer Mohamed; El-Sheikh, Mohamed M; Abd El-Fattah, Fadel

    2015-01-01

    The purpose of this study was to clinically and radiographically compare implant-connected and tooth-connected implant-supported fixed-detachable mandibular partial dentures. Twenty partially edentulous patients (age range: 25 to 50 years) with mandibular Kennedy Class II configurations were equally divided into two groups receiving a three-unit, fixed-detachable, screw-retained partial denture. Group 1 comprised patients with unilateral missing mandibular molars and premolars. Two implants were placed at the mandibular first premolar and first molar areas. Group 2 comprised patients with missing mandibular molars and second premolars. An implant was placed at the mandibular first molar area, the first premolar was prepared, and a coping was cemented to the tooth with permanent cement. Each case was evaluated clinically and radiographically at baseline (partial denture insertion) and after 6, 12, and 24 months. Data were collected and statistically analyzed using repeated-measures one-way and two-way analysis of variance tests. There was no statistically significant difference between the two groups (P > .05). The implant-tooth-supported prosthesis provided an equally predictable treatment option compared to the totally implant-supported prosthesis in terms of implant survival and loss of marginal bone.

  20. Two-year clinical and SEM evaluation of glass-fiber-reinforced inlay fixed partial dentures.

    PubMed

    Göhring, Till N; Schmidlin, Patrick R; Lutz, Felix

    2002-02-01

    To clinically evaluate conservative fiber-reinforced composite inlay fixed partial dentures (IFPDs) bonded to inlay abutments. Forty fiber-reinforced composite IFPDs were made for 29 patients. Restorations were manufactured with the composite Targis reinforced by Vectris prefabricated glass-fiber elements and were inserted with a high viscosity insertion technique. Forty bonded IFPDs were examined clinically after 1 year, and 25 after 2 years, using modified USPHS criteria. Twenty-five abutment inlays and 12 pontics were analyzed quantitatively by scanning electron microscopy SEM. Results were tested for statistical significance with ANOVA. Although most clinical criteria were rated "alpha", four IFPDs had to be replaced: two retainers debonded and two presented total delamination of veneering material from fiber framework. Two partial delaminations were repaired intraorally. No fractures of framework were observed. SEM marginal analysis of tooth-composite interface exhibited 96.5 +/- 3.0% continuous margin at baseline, 91.0 +/- 5.7% at the 1-year and 89.6 +/- 5.2% at the 2-year recall. Decrease of marginal quality was statistically significant between baseline and 1 year (P= 0.001), but not between 1- and 2-year recalls.

  1. Veneering technique for a Ti-6Al-7Nb framework used in a resin-bonded fixed partial denture with a highly filled indirect composite.

    PubMed

    Matsumura, Hideo; Yoneyama, Takayuki; Shimoe, Saiji

    2002-12-01

    This article presents a veneering technique for fixed partial denture frameworks made from a Ti-6Al-7Nb alloy. The fixed partial denture framework was prepared with a magnesia-based mold material and a centrifugal casting machine. An esthetic veneer was fabricated with a highly filled dual-polymerized composite material and a metal-conditioning agent. This technique can be applied as a standardized veneering procedure for the titanium alloy, for which porcelain fusing is currently difficult.

  2. A 3-year longitudinal study of quality-of-life outcomes of elderly patients with implant- and tooth-supported fixed partial dentures in posterior dental regions.

    PubMed

    Petricevic, Nikola; Celebic, Asja; Rener-Sitar, Ksenija

    2012-06-01

    Clinical studies have mainly been focused on oral health-related quality-of-life (OHRQoL) outcomes of removable dentures. To evaluate therapy of elderly patients with implant-supported fixed partial dentures (IFPD) and tooth-supported fixed partial dentures (FPD) in the posterior dental regions. The OHIP49 was used to measure OHRQoL in 64 patients with IFPD and 38 patients with FPD, before, 3 weeks and 3 years after rehabilitation. A control group (CG) consisted of 62 individuals. The Oral Health Impact Profile questionnaire (OHIP) follow-up scores of the patients with FPD and the patients with IFPD were significantly smaller in comparison with the baseline scores (p < 0.01). The OHIP scores were further reduced at the 3-year follow-up. The patients with IFPD had significantly higher scores than the patients with FPD and the CG at the baseline and at the follow-ups. In the patients with FPD, both age groups (≤60 and >60) showed equal improvement of the OHRQoL. In the IFPD group, patients older than 60 years showed better improvement (p < 0.05). There were no significant differences dependent on gender and antagonistic teeth (p > 0.05). The FPD and the IFPD treatment showed significant improvement of OHRQoL. The FPD treatment improved OHRQoL equally in both age groups, while the IFPD treatment improved OHRQoL better in older patients. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  3. The effectiveness of adding a supporting implant in stress distribution of long span fixed partial denture (three-dimensional finite element analysis)

    PubMed Central

    Mozayek, Rami Shurbaji; Mozayek, Mohammad Yamen Shurbaji; Allaf, Mirza; Abouharb, Mohammad Bassam

    2016-01-01

    Context and Aims: Long span is seen in many clinical situations; treatment planning options of these cases are difficult and may require: Fixed partial denture (FPD), removable partial denture, or implant supported prostheses. Each option has its own disadvantages: Mechanical, patient relief, and cost, respectively. This article will evaluate the stress distribution of another treatment option, which is adding a single supporting implant to the FPD using three-dimensional (3D) finite element analysis. Subjects and Methods: Three models, each consisting of 5 units, were created as following: (1) Tooth pontic pontic pontic tooth, (2) tooth pontic implant pontic tooth, (3) tooth pontic pontic implant tooth. An axial force was applied to the prostheses using 3D finite element method, and stress was evaluated. Results: Maximum stress was found in the prostheses in all models, highest stress values in all shared components of the models were close. Stress in implants was less in the second model than the third one. Conclusions: Adding a supporting implant in long span FPD has no advantages, whereas it has the disadvantages of complicating treatment and the complications that may occur to the implant and surrounding bone itself. PMID:27621545

  4. Free-end saddle length influence on stress level in unilateral complex partial denture abutment teeth and retention elements.

    PubMed

    Patrnogić, Vesna; Todorović, Aleksandar; Sćepanović, Miodrag; Radović, Katarina; Vesnić, Jelena; Grbović, Aleksandar

    2013-11-01

    Different types of dental restorations are used for the therapy of unilateral free-end saddle edentulism. Unilateral complex partial denture is one of the indications for the Kennedy class II partial edentulism. The abscence of major connector and denture plate is an advantage compared to the conventional restorations, because of better comfort and shorter period of adaptation. The aim of the study was to analyse the influence of free-end saddle length change on the behaviour of unilateral complex partial denture supporting structures. Stress levels of the canine and the first premolar as retentional teeth and the attachments were tested under the influence of physiological forces with the loading point shifting distally in relation to the saddle length change. A virtual real size 3D model of the fixed part of the restoration (the canine and the first premolar with milled crowns) was created using the CATIA computer program. It was connected to the mobile part of partial denture with the SD snap in latch attachment. Mobile part of the restoration was designed in the region of 2, 3 and 4 lateral teeth (second premolar, first, second and third molar). By using the finite element method (FEM) stress levels analysis was performed under the load of physiological forces of 150 N in the free-end saddle teeth zone. The results of analysis show that physiological forces cause a different stress distribution on the abutment teeth and the attachment, depending on the saddle length. The stress level values obtained for the abutment teeth as well as the attachment are far lower than the marginal ones. The behaviour of the system changes under this defined stress, but no plastic deformation occurs.

  5. Changes in the composition of a nickel-base partial denture casting alloy upon fusion and casting.

    PubMed

    Lewis, A J

    1975-02-01

    Three series of tensile test pieces were produced using a nickel-base partial denture casting alloy. For the first series induction heating was employed for melting the alloy, for the second a resistance crucible, and for the third an oxy-acetylene torch. In each series the same metal was cast sequentially five times, following which samples of the alloy were subjected to a ten element quantitative analysis to ascertain compositional changes associated with the three methods of fusion.

  6. Technique for fabricating individualized dentures with a gingiva-shade composite resin.

    PubMed

    Park, Beom-Woo; Kim, Nam-Jin; Lee, Jonghyuk; Lee, Hae-Hyoung

    2016-05-01

    More natural dental esthetics have been sought by patients who wear conventional complete or partial dentures. Recently, gingiva-shade composite resins (GSCRs) have become available for replicating soft tissue for both fixed and removable prostheses. The technique presented is for fabricating individualized complete dentures. First the acrylic resin is mixed with a coloring agent and processed to modify the base shade of the denture. GSCRs are light polymerized onto a prepared space on the buccal surfaces of denture base to replicate the appearance of gingival tissues including blood vessels. The technique provides an outstanding natural, gingiva-like, appearance and allows complete dentures to harmonize with the individual patient's surrounding oral tissues.

  7. Interventions for cleaning dentures in adults.

    PubMed

    de Souza, Raphael Freitas; de Freitas Oliveira Paranhos, Helena; Lovato da Silva, Claudia H; Abu-Naba'a, Layla; Fedorowicz, Zbys; Gurgan, Cem A

    2009-10-07

    Removing denture plaque may be essential for maintaining the oral health of edentulous people. Brushing and soaking in chemical products are two of the most commonly used methods of cleaning dentures. To evaluate the effectiveness and safety of different methods for cleansing removable dentures. We searched the following databases: the Cochrane Oral Health Group Trials Register (to May 2009); CENTRAL (The Cochrane Library 2009, Issue 2); MEDLINE (1965 to May 2009); EMBASE (1980 to May 2009); LILACS (1980 to May 2009); and CINAHL (1997 to May 2009). There were no language restrictions. Randomised controlled trials (RCTs) comparing any mechanical method (e.g. brushing or ultrasound) or chemical (e.g. enzymes, sodium hypochlorite, oral rinses or peroxide solutions) in adults over the age of 18 wearing removable partial dentures or complete dentures.The primary outcomes considered were the health of denture bearing areas (soft tissues, periodontal tissues and teeth) and participants' satisfaction and preference. Secondary outcomes included denture plaque coverage area, indicators of halitosis and microbial counts on abutment teeth, soft tissues or denture base or saliva. Two independent review authors screened and extracted information from, and independently assessed the risk of bias in the included trials. Although six RCTs were included in this review, the wide range of different interventions and outcome variables did not permit pooling of data in a meta-analysis. Isolated reports indicated that chemicals and brushing appear to be more effective than placebo in the reduction of plaque coverage and microbial counts of anaerobes and aerobes on complete denture bases. There is a lack of evidence about the comparative effectiveness of the different denture cleaning methods considered in this review. Few well designed RCTs were found. Future research should focus on comparisons between mechanical and chemical methods; the assessment of the association of methods

  8. Fracture behavior of inlay and onlay fixed partial dentures - An in-vitro experimental and XFEM modeling study.

    PubMed

    Zhang, Zhongpu; Thompson, Mark; Field, Clarice; Li, Wei; Li, Qing; Swain, Michael V

    2016-06-01

    This study aimed to explore the "sensitivity" of the fracture load and initiation site to loading position on the central occlusal surface of a pontic tooth for both all-ceramic inlay retained and onlay supported partial denture systems. Three dimensional (3D) finite element (FE) inlay retained and onlay supported partial denture models were established for simulating crack initiation and propagation by using the eXtended Finite Element Method (XFEM). The models were subjected to a mastication force up to 500N on the central fossa of the pontic. The loading position was varied to investigate its influence on fracture load and crack path. Small perturbation of the loading position caused the fracture load and crack pattern to vary considerably. For the inlay fixed partial dentures (FPDs), the fracture origins changed from the bucco-gingival aspect of the molar embrasure to the premolar embrasure when the indenter force location is slightly shifted from the mesial to distal side. In contrast, for onlay FPDs, cracking initiated from bucco-gingival aspect of the premolar embrasure when the indenter is slightly shifted to the buccal side and from molar embrasure when the indenter is shifted to the lingual side. The fracture load and cracking path were found to be very sensitive to loading position in the all-ceramic inlay and onlay FPDs. The study provides a basis for improved understanding on the role of localized contact loading of the cusp surface in all-ceramic FPDs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. All-ceramic inlay-retained fixed partial dentures: preliminary results from a clinical study.

    PubMed

    Ohlmann, Brigitte; Rammelsberg, Peter; Schmitter, Marc; Schwarz, Stefanie; Gabbert, Olaf

    2008-09-01

    The objective of this study was to evaluate the clinical performance of zirconia-based all-ceramic fixed partial dentures anchored by inlays. A total of thirty FPDs, manufactured using a zirconia frame and veneered with press ceramic, were anchored by use of inlay retainers. All FPDs were designed to replace one missing molar and were adhesively luted by use of one of two different resin cements. Documentation included failures and other complications, plaque accumulation, and aesthetic and functional performance. Statistical analysis was performed using a cox-regression model. During the 12 months observation period a total of thirteen clinically relevant complications occurred-four delaminations of the veneer and six decementations. Three FPDs had to be replaced because of a fracture of the framework. The cement chosen, the location, and the design of the retainer had no statistically significant effect on the occurrence of complications. During the observation period, accumulation of plaque on the abutment teeth was not significantly greater than on reference teeth. Postoperative sensitivity did not differ significantly between the different luting cement groups. The aesthetic and functional performance of the FPDs was acceptable. Improved adhesion between resin cement and inlay retainer is desirable before general recommendation of all-ceramic inlay-retained FPDs. Use of different luting cements seems to have no effect on the occurrence of complications.

  10. Fracture resistance of three-unit zirconia fixed partial denture with modified framework.

    PubMed

    Partiyan, Arthur; Osman, Essam; Rayyan, Mohammad M; Aboushelib, Moustafa; Ibrahim, Ahmed; Jimbo, Ryo

    2017-01-01

    Obtaining ideal prosthetic framework design is at times hindered by anatomical limitations in the posterior region that might increase the risk for zirconia restoration fracture. Modification such as increasing the bulk thickness especially in the connector region could result in strengthening the zirconia framework. Three-unit zirconia fixed partial dentures replacing mandibular molars were fabricated using the following two techniques: CAD/CAM technology and manual copy milling. Modified framework with unveneered full thickness connectors were designed and fabricated with the aforementioned methods. Conventional frameworks (0.5 mm thick with rounded 3 mm connectors) served as control (N = 20). After cementation on epoxy dies, the frameworks were loaded to fracture in a universal testing machine. Fractured surfaces were prepared for examination using scanning electron microscopy. Statistical analysis revealed significant differences in fracture resistance between conventional and modified framework design for both fabrication techniques tested. SEM examination indicated that critical crack originated at the tensile surface of the connectors for conventional frameworks. The critical crack for modified frameworks occurred on the axial wall of the abutments. The modification of the zirconia framework design presented significant improvement of the fracture resistance compared to the conventional design.

  11. Restoring Anterior Aesthetics by a Rotational Path Cast Partial Denture: An Overlooked Technique

    PubMed Central

    Bhat, Bala Saraswati; Arora, Himanshu

    2016-01-01

    Cast Partial Dentures (CPD) has long been known to restore missing teeth in patients with minimal invasion on hard and soft tissues. Although satisfactory otherwise, the main concern in CPD is the anterior display of metal. Also the technique sensitive lab procedures, together with the esthetic concern have built an iceberg around the frequent utilization of this treatment modality. With the advent of various techniques to get rid of the metallic display, it was predicted to have more CPD’s done in the dental arena. But the conceptual technicalities of the procedure took away the limelight from this treatment modality and focused on the fixed prosthodontics. Although feasible in a large number of patients, fixed prosthesis still has areas of restriction. It is here, when we apply our knowledge and skill of esthetic CPD. Esthetic CPD eliminates the metal display by utilizing desirable undercuts. The engaging action of the framework into these undercuts paves way for a rotational motion to seat the remaining prosthesis. Hence dual path of insertion helps eliminating the anterior clasp. In this case report dual path of insertion is discussed for replacing anterior teeth in an old male patient who had mild esthetic concerns. Following the conservative approach of CPD (over FPD) esthetic and restorative treatment was planned with patient’s consent. PMID:27437375

  12. Theoretical axial wall angulation for rotational resistance form in an experimental-fixed partial denture.

    PubMed

    Bowley, John Francis; Kaye, Elizabeth Krall; Garcia, Raul Isidro

    2017-08-01

    The aim of this study was to determine the influence of long base lengths of a fixed partial denture (FPD) to rotational resistance with variation of vertical wall angulation. Trigonometric calculations were done to determine the maximum wall angle needed to resist rotational displacement of an experimental-FPD model in 2-dimensional plane. The maximum wall angle calculation determines the greatest taper that resists rotation. Two different axes of rotation were used to test this model with five vertical abutment heights of 3-, 3.5-, 4-, 4.5-, and 5-mm. The two rotational axes were located on the mesial-side of the anterior abutment and the distal-side of the posterior abutment. Rotation of the FPD around the anterior axis was counter-clockwise, Posterior-Anterior (P-A) and clockwise, Anterior-Posterior (A-P) around the distal axis in the sagittal plane. Low levels of vertical wall taper, ≤ 10-degrees, were needed to resist rotational displacement in all wall height categories; 2-to-6-degrees is generally considered ideal, with 7-to-10-degrees as favorable to the long axis of the abutment. Rotation around both axes demonstrated that two axial walls of the FPD resisted rotational displacement in each direction. In addition, uneven abutment height combinations required the lowest wall angulations to achieve resistance in this study. The vertical height and angulation of FPD abutments, two rotational axes, and the long base lengths all play a role in FPD resistance form.

  13. Comparative evaluation of retentive properties of acid etched resin bonded fixed partial dentures.

    PubMed

    Arora, Vimal; Sharma, M C; Dwivedi, Ravi

    2014-01-01

    Little consensus exist in suitable tooth preparation design and alloy pre-treatment methods for improving the retention of resin bonded fixed partial dentures (RBFPDs). An in-vitro experiment was done with four designs. Group A: standard form, B: wings and proximal slices, C: wings, proximal slice and grooves, D: wings, proximal slice, grooves and occlusal coverage. Alloys were subjected to pre-treatment procedures like Group I: control, II: sand blasting, III: electro etching, IV: tin plating. Debonding forces of the castings were recorded in a universal testing machine and results were analyzed by student's 't' test. Group B, C and D showed higher debonding forces compared to A. However, there were no significant differences in mean force values among Groups B, C and D. Group II, III and IV with different alloy pre-treatment methods demonstrated higher values against control. Inter group variations among Group II, III and IV were not significant. Tooth preparation with adequate surface extensions and pre-treatment procedures of casting alloys are two parameters that play important role in determining the retentive features of RBFPDs. Different types of tooth preparation designs and alloy pre-treatment methods exert almost similar influence in increasing the retention of acid etched RBFPDs.

  14. Comparative evaluation of retentive properties of acid etched resin bonded fixed partial dentures

    PubMed Central

    Arora, Vimal; Sharma, M.C.; Dwivedi, Ravi

    2013-01-01

    Background Little consensus exist in suitable tooth preparation design and alloy pre-treatment methods for improving the retention of resin bonded fixed partial dentures (RBFPDs). Methods An in-vitro experiment was done with four designs. Group A: standard form, B: wings and proximal slices, C: wings, proximal slice and grooves, D: wings, proximal slice, grooves and occlusal coverage. Alloys were subjected to pre-treatment procedures like Group I: control, II: sand blasting, III: electro etching, IV: tin plating. Debonding forces of the castings were recorded in a universal testing machine and results were analyzed by student's ‘t’ test. Results Group B, C and D showed higher debonding forces compared to A. However, there were no significant differences in mean force values among Groups B, C and D. Group II, III and IV with different alloy pre-treatment methods demonstrated higher values against control. Inter group variations among Group II, III and IV were not significant. Conclusion Tooth preparation with adequate surface extensions and pre-treatment procedures of casting alloys are two parameters that play important role in determining the retentive features of RBFPDs. Different types of tooth preparation designs and alloy pre-treatment methods exert almost similar influence in increasing the retention of acid etched RBFPDs. PMID:24623948

  15. Marginal adaptation analysis performed with en face optical coherence tomography in fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Antonie, Sergiu; Dobre, George; Bradu, Adrian; Hughes, Michael; Rominu, Mihai; Podoleanu, Adrian Gh.

    2009-02-01

    Frameworks for fixed partial denture made out of dental alloys thought classic techniques currently involve many errors like marginal and internal gaps. The aim of this study is to present alternative technologies in making frameworks from dental alloys using selective laser sintering/ selective laser melting (SLS/ SLM) and to investigate the marginal adaptation of the fixed dental prostheses using the en face optical coherence tomography. These procedures imply the use of a scanning device PROBIS, SMART OPTICS with the help of 3D Dental Scanner software. For digitizing the 3D model we used the Dental Wings Kunde Software. The files obtained were sent to a SLS/ SLM machine, Hint-Els rapidPro, where the CoCr powder was sintered/melt by selectively consolidating successive layers of powder material on top of each other, using thermal energy supplied by a focused and computer controlled laser beam. Through this technique can be produced up to 80 pieces in only one step. A parallel between the classic casting technique and this new technology reveal the least has several advantages: fast finishing time, excellent marginal and internal fit, biocompatibility and superior chemical properties. SLS/ SLM proved to be a promising technology that may overcome the classic ones, because of the superior marginal fit of the fixed dental prostheses to the teeth.

  16. Influence of connector design on fracture probability of ceramic fixed-partial dentures.

    PubMed

    Oh, W; Götzen, N; Anusavice, K J

    2002-09-01

    Fracture of ceramic fixed-partial dentures (FPDs) tends to occur in the connector area because of stress concentrations. The objective of this study was to test the hypothesis that the radius of curvature at the gingival embrasure of the FPD connector significantly affects the fracture resistance of three-unit FPDs. Two three-dimensional finite element models (FEMs), representing two FPD connector designs, were created in a manner corresponding to that described in a previous experimental study (Oh, 2002). We performed fractographic analysis and FEM analyses based on CARES (NASA) post-processing software to determine the crack initiation site as well as to predict the characteristic strength, the location of peak stress concentrations, and the risk-of-rupture intensities. A good correlation was found between the experimentally measured failure loads and those predicted by FEM simulation analyses. Fractography revealed fracture initiation at the gingival embrasure, which confirms the numerically predicted fracture initiation site. For the designs tested, the radius of curvature at the gingival embrasure strongly affects the fracture resistance of FPDs.

  17. Restoring Anterior Aesthetics by a Rotational Path Cast Partial Denture: An Overlooked Technique.

    PubMed

    Sharma, Deeksha; Bhat, Bala Saraswati; Arora, Himanshu

    2016-05-01

    Cast Partial Dentures (CPD) has long been known to restore missing teeth in patients with minimal invasion on hard and soft tissues. Although satisfactory otherwise, the main concern in CPD is the anterior display of metal. Also the technique sensitive lab procedures, together with the esthetic concern have built an iceberg around the frequent utilization of this treatment modality. With the advent of various techniques to get rid of the metallic display, it was predicted to have more CPD's done in the dental arena. But the conceptual technicalities of the procedure took away the limelight from this treatment modality and focused on the fixed prosthodontics. Although feasible in a large number of patients, fixed prosthesis still has areas of restriction. It is here, when we apply our knowledge and skill of esthetic CPD. Esthetic CPD eliminates the metal display by utilizing desirable undercuts. The engaging action of the framework into these undercuts paves way for a rotational motion to seat the remaining prosthesis. Hence dual path of insertion helps eliminating the anterior clasp. In this case report dual path of insertion is discussed for replacing anterior teeth in an old male patient who had mild esthetic concerns. Following the conservative approach of CPD (over FPD) esthetic and restorative treatment was planned with patient's consent.

  18. Oral Health of Patients Treated with Acrylic Partial Dentures Using a Toothpaste Containing Bee Product.

    PubMed

    Wiatrak, Karolina; Morawiec, Tadeusz; Rój, Rafał; Mertas, Anna; Machorowska-Pieniążek, Agnieszka; Kownacki, Patryk; Tanasiewicz, Marta; Skucha-Nowak, Małgorzata; Baron, Stefan; Piekarz, Tomasz; Wrzoł, Maciej; Bogacz, Mateusz; Kasperski, Jacek; Niedzielska, Iwona

    2017-01-01

    This study was carried out to investigate the influence of a propolis and tee tree oil-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Thirty-seven patients who underwent oral rehabilitation with a removable acrylic denture were selected and randomly assigned into two groups: study group (A) which received a newly formulated propolis and tee tree oil-containing toothpaste or a control group (C) without an active ingredient. API, S-OHI, and mSBI were assessed in three subsequent stages. During each examination swabs were employed for microbiological inoculation: in the study group after 4 weeks use of the active toothpaste showed a decrease in the number of isolated microorganisms. In the control group, after 4 weeks use of the toothpaste without active ingredients resulted in increase in the number of the isolated microorganisms. Improvements in hygiene and the condition of periodontium were observed in patients using active toothpastes. In the study group the oral flora diversity was reduced by the decrease in the number of cultured microorganism species, while in the control group an increase in the number of cultured microorganisms and their species was observed.

  19. Oral Health of Patients Treated with Acrylic Partial Dentures Using a Toothpaste Containing Bee Product

    PubMed Central

    Kownacki, Patryk; Tanasiewicz, Marta; Piekarz, Tomasz; Bogacz, Mateusz; Kasperski, Jacek; Niedzielska, Iwona

    2017-01-01

    This study was carried out to investigate the influence of a propolis and tee tree oil-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Thirty-seven patients who underwent oral rehabilitation with a removable acrylic denture were selected and randomly assigned into two groups: study group (A) which received a newly formulated propolis and tee tree oil-containing toothpaste or a control group (C) without an active ingredient. API, S-OHI, and mSBI were assessed in three subsequent stages. During each examination swabs were employed for microbiological inoculation: in the study group after 4 weeks use of the active toothpaste showed a decrease in the number of isolated microorganisms. In the control group, after 4 weeks use of the toothpaste without active ingredients resulted in increase in the number of the isolated microorganisms. Improvements in hygiene and the condition of periodontium were observed in patients using active toothpastes. In the study group the oral flora diversity was reduced by the decrease in the number of cultured microorganism species, while in the control group an increase in the number of cultured microorganisms and their species was observed. PMID:28265291

  20. Clinical Fit of Partial Removable Dental Prostheses Based on Alginate or Polyvinyl Siloxane Impressions.

    PubMed

    Fokkinga, Wietske A; Witter, Dick J; Bronkhorst, Ewald M; Creugers, Nico H

    The aim of this study was to analyze the clinical fit of metal-frame partial removable dental prostheses (PRDPs) based on custom trays used with alginate or polyvinyl siloxane impression material. Fifth-year students of the Nijmegen Dental School made 25 correct impressions for 23 PRDPs for 21 patients using alginate, and 31 correct impressions for 30 PRDPs for 28 patients using polyvinyl siloxane. Clinical fit of the framework as a whole and of each retainer separately were evaluated by calibrated supervisors during framework try-in before (first evaluation) and after (second evaluation) possible adjustments (score 0 = poor fit, up to score 3 = good fit). Framework fit and fit of the denture base were evaluated at delivery (third evaluation). Finally, postinsertion sessions were evaluated and total number of sessions needed, sore spots, adjustments to the denture base, and reported food-impaction were recorded. No significant differences in clinical fit (of the framework as a whole, for the retainers, or for the denture base) were found between the groups in the three evaluation sessions. Differences were not found for postinsertion sessions with one exception: in the alginate group, four subjects reported food impaction, versus none in the polyvinyl siloxane group. Clinical fit of metal-frame PRDPs based on impressions with custom trays combined with alginate or polyvinyl siloxane was similar.

  1. Denture care practice among patients attending the prosthetic clinic in a Nigerian teaching hospital

    PubMed Central

    Ogunrinde, Tunde Joshua; Opeodu, Olanrewaju Ige

    2015-01-01

    Background: Good denture care practice by individuals using Removable Partial Denture (RPD) is an important component of oral health measures. An assessment of denture care practice of such individuals by dental care practitioners is necessary. Objective: To evaluate the denture care practice among prosthetics patients attending a tertiary Hospital Dental Centre in Nigeria. Materials and Methods: An interviewer administered questionnaire was used to obtain information from RPD wearers that were willing to participate. The questionnaire assessed among other things, patients’ bio-data, frequency, techniques and device used for cleaning their dentures. Data was analyzed using Chi-square test (P < 0.05). Results: One hundred and ninety eight denture wearers consisting of 100 (50.5%) males and 98 (49.5%) females participated in the study. Majority 110 (55.6%) cleaned their dentures once daily and toothbrush and pastes were used by 105 (53%) of the participants. More than 70% of the respondents removed their dentures at night. One hundred and sixty-six (83.8%) visited the dentist only when they needed treatment. There was a statistical significant relationship between frequency and technique of cleaning denture, and denture cleanliness (P < 0.05). Conclusion: This study shows that once daily cleaning of dentures and cleaning the denture with rest of the teeth are ineffective in prevention of plaque accumulation. PMID:26229229

  2. Comparison of 2 bonding systems and survival of fiber-reinforced composite inlay fixed partial dentures.

    PubMed

    Monaco, Carlo; Ferrari, Marco; Caldari, Mauro; Baldissara, Paolo; Scotti, Roberto

    2006-01-01

    This pilot clinical trial evaluated the clinical behavior of 3-unit inlay fixed partial dentures (IFPDs) made of the glass-fiber composite system SR Adoro/Vectris and luted with 2 different bonding systems over an observation period of 2 years. Thirty-nine glass-fiber-reinforced composite IFPDs were made to replace 1 missing maxillary or mandibular tooth. Nineteen IFPDs were randomly assigned to group A and luted with a 2-step bonding system (Excite DSC), while the other 20 IFPDs of group B were cemented with a 3-step adhesive (Syntac). Events such as partial or total debonding of the IFPDs, fracture of the framework, or veneer and fiber exposures were considered failures. Color match, marginal discoloration, secondary caries, marginal adaptation, postoperative sensitivity, and surface texture were evaluated according to the United States Public Health Service modified criteria. Two debondings and 2 fiber exposures occurred during the observation period. All failures occurred in group A. Some fatigue microcracks in the pontic area of the 2 detached IFPDs were observed under scanning electron microscopy. The postoperative sensitivity of group A was much higher than that of group B, and the abutments luted with Excite DCS showed postoperative sensitivity during the first month in 42.2% of cases. The sensitivity disappeared completely after 6 months. Statistical analysis indicated significant differences in postoperative sensitivity (P < .05) between the 2 groups. The IFPDs bonded with a 3-step adhesive demonstrated good clinical service in the short observation period. The microfractures of the layering material observed on the debonded IFPDs may suggest excessive flexibility of the fiber structures, which occurs if the framework is fabricated without observing the recommended dimensions.

  3. Vinyl polysiloxane impression material in removable prosthodontics. Part 2: immediate denture and reline impressions.

    PubMed

    Cagna, David R; Massad, Joseph J

    2009-01-01

    Accurate impressions are important elements in both the fabrication and maintenance phases of complete denture therapy. For patients possessing nonrestorable, periodontally hopeless residual dentitions, immediate denture therapy is often the treatment of choice. An impression procedure capable of accurately registering functional vestibular anatomy facilitates successful therapy. For complete dentures currently in function, periodic assessment and correction of fit extends long-term prosthesis performance. To maintain optimal tissue-base relationships, use of specialized impressions, and subsequent laboratory reline procedures is often indicated. For both of these impression procedures (i.e., immediate denture impressions and denture reline impressions), vinyl polysiloxane (VPS) impression material offers distinct advantages. Part 2 of this article series reports on the use of VPS for immediate denture and reline impression procedures.

  4. Vinyl polysiloxane impression material in removable prosthodontics. Part 2: Immediate denture and reline impressions.

    PubMed

    Cagna, David R; Massad, Joseph J

    2007-09-01

    Accurate impressions are important elements in both the fabrication and maintenance phases of complete denture therapy. For patients possessing nonrestorable, periodontally hopeless residual dentitions, immediate denture therapy is often the treatment of choice. An impression procedure capable of accurately registering functional vestibular anatomy facilitates successful therapy. For complete dentures currently in function, periodic assessment and correction of fit extends long-term prosthesis performance. To maintain optimal tissue-base relationships, use of specialized impressions, and subsequent laboratory reline procedures is often indicated. For both of these impression procedures (ie, immediate denture impressions and denture reline impressions), vinyl polysiloxane (VPS) impression material offers distinct advantages. Part 2 of this article series reports on the use of VPS for immediate denture and reline impression procedures.

  5. Removable dentures and relations between their construction, adaptation and functionality role and influence on dysgeusia.

    PubMed

    Zwolak, Agnieszka; Bakalczuk, Magdalena; Leszcz, Przemysław; Szabelska, Anna; Sarna-Boś, Katarzyna; Kleinrok, Janusz

    2004-01-01

    A large foreign body inserted into oral cavity, e.g. complete denture, both lower and upper, might cause a temporary or constant dysarthia and dysgeusia. These might be reduced and even completely eliminated by proper dentures construction. Problems with normal articulation might result from construction faults, e.g. too thick denture base, incorrect denture base modelling, wrong teeth placement, lowering or excessive height occlusion. The hypogeusia has been repeatedly observed as the symptom in the course of the complete denture adaptation stage, as well as might keep further. The main role in the mechanism of occurrence of hypogeusia has the limitation of the lingual flexibility, especially of its tip, throughout the use of the complete denture. It provokes difficulties with the accurate course of its physiological activity as well as makes impossible the balancing with the tongue of the cryaesthesia, heath sensibility and tactile sense, which are blocked on the palate.

  6. Inhibitory effect of zirconium oxide nanoparticles on Candida albicans adhesion to repaired polymethyl methacrylate denture bases and interim removable prostheses: a new approach for denture stomatitis prevention.

    PubMed

    Gad, Mohammed M; Al-Thobity, Ahmad M; Shahin, Suliman Y; Alsaqer, Badar T; Ali, Aiman A

    2017-01-01

    of zirconia nanoparticles to cold-cured acrylic resin is an effective method for reducing Candida adhesion to repaired polymethyl methacrylate (PMMA) denture bases and cold-cured removable prosthesis. Based on the results of the current study, zirconia nanoparticles have an antifungal effect, which could be incorporated in the repair material for repairing denture bases and in PMMA removable prostheses as a possible approach for denture stomatitis prevention.

  7. Effect of polyester fiber reinforcement on the mechanical properties of interim fixed partial dentures

    PubMed Central

    Gopichander, N.; Halini Kumarai, K.V.; Vasanthakumar, M.

    2015-01-01

    Background Different reinforcements currently available for interim fixed partial denture (FPD) materials do not provide the ideal strength for long-term use. Therefore, the aim of this investigation was to develop a more ideal provisional material for long-term use with better mechanical properties. This study evaluated the effectiveness of polyester fiber reinforcement on different interim FPD materials. Methods Thirty resin-bonded FPDs were constructed from three provisional interim FPD materials. Specimens were tested with a universal testing machine (UTM). The modulus of elasticity and flexural strength were recorded in MPa. The compressive strength and degree of deflection were calculated from the obtained values, and a two-way analysis of variance (ANOVA) was used to determine the significance. Results The polyester fiber reinforcement increased the mechanical properties. The modulus of elasticity for heat-polymerized polymethyl methacrylate (PMMA) was 624 MPa, compared to 700.2 MPa for the reinforced heat-cured sample. The flexural strengths of the bis-acrylic and cold-polymerized reinforced samples increased significantly to 2807 MPa and 979.86 MPa, respectively, compared to the nonreinforced samples. The mean compressive strength of the reinforced cold-polymerized PMMA samples was 439.17 MPa; and for the reinforced heat-polymerized PMMA samples, it was 1117.41 MPa. The degree of deflection was significantly greater (P < 0.05) in the reinforced bis-acrylic sample (5.03 MPa), compared with the nonreinforced bis-acrylic sample (2.95 MPa). Conclusion Within the limitations of this study, polyester fiber reinforcements improved the mechanical properties of heat-polymerized PMMA, cold-polymerized PMMA, and bis-acrylic provisional FPD materials. PMID:26644754

  8. Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

    PubMed

    Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

    2014-01-01

    This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

  9. Theoretical axial wall angulation for rotational resistance form in an experimental-fixed partial denture

    PubMed Central

    2017-01-01

    PURPOSE The aim of this study was to determine the influence of long base lengths of a fixed partial denture (FPD) to rotational resistance with variation of vertical wall angulation. MATERIALS AND METHODS Trigonometric calculations were done to determine the maximum wall angle needed to resist rotational displacement of an experimental-FPD model in 2-dimensional plane. The maximum wall angle calculation determines the greatest taper that resists rotation. Two different axes of rotation were used to test this model with five vertical abutment heights of 3-, 3.5-, 4-, 4.5-, and 5-mm. The two rotational axes were located on the mesial-side of the anterior abutment and the distal-side of the posterior abutment. Rotation of the FPD around the anterior axis was counter-clockwise, Posterior-Anterior (P-A) and clockwise, Anterior-Posterior (A-P) around the distal axis in the sagittal plane. RESULTS Low levels of vertical wall taper, ≤ 10-degrees, were needed to resist rotational displacement in all wall height categories; 2–to–6–degrees is generally considered ideal, with 7–to–10–degrees as favorable to the long axis of the abutment. Rotation around both axes demonstrated that two axial walls of the FPD resisted rotational displacement in each direction. In addition, uneven abutment height combinations required the lowest wall angulations to achieve resistance in this study. CONCLUSION The vertical height and angulation of FPD abutments, two rotational axes, and the long base lengths all play a role in FPD resistance form. PMID:28874995

  10. Periodontal tissue responses after insertion of artificial crowns and fixed partial dentures.

    PubMed

    Knoernschild, K L; Campbell, S D

    2000-11-01

    The purpose of this review was, first, to critically evaluate published evidence on the effects of artificial crowns and fixed partial dentures (FPDs) on adjacent periodontal tissue health, and second to synthesize this evidence into meaningful summaries. Restoration qualities that contribute to inflammatory responses were identified based on strength of evidence, and variables that should be controlled in future investigations were outlined. Such information is necessary to accurately predict the prognosis of periodontal tissues adjacent to crowns or FPDs. Clinical trial and epidemiologic evidence published in English was collected. The effects of crowns or FPDs on gingival inflammation, probing depths, and bone loss were evaluated based on accuracy of measurement, reliability of measurement, and/or appropriateness of data analysis. Crowns and FPDs increased the incidence of advanced gingival inflammation adjacent to restorations, particularly if restorations had intracrevicular finish line placement, poor marginal adaptation, or rough surfaces. However, because of the limitation in the accuracy and reliability of probing depth measurements, reports of greater mean probing depths of crowned teeth, which tended to be less than 1 mm greater than control teeth, should be questioned. Finally, crowns and FPDs in general did not accelerate the rate of adjacent bone loss. Clinically deficient restorations, as well as clinically acceptable restorations, can contribute to gingival inflammation. However, with the limitations of the applied methods of measurement, current evidence has not shown an increased attachment loss adjacent to crowns or FPDs. Future trials should document periodontal health before therapy and periodically after restoration insertion so that each tooth serves as its own control. In future studies, the periodontal disease history of the patient, the influence of the restoration on plaque formation, and the composition of the crevicular microflora must

  11. Temperature rise on dentin caused by temporary crown and fixed partial denture materials: influencing factors.

    PubMed

    Seelbach, Paul; Finger, Werner J; Ferger, Paul; Balkenhol, Markus

    2010-12-01

    Temporary crowns and fixed partial denture materials (t-c&b) generate exothermic heat during polymerization. The amount of temperature, reaching the pulp chamber, is dependent on the residual thickness of the prepared dentin as well as the volume of the t-c&b used. Hence, the aim of this study was to investigate the influence of both factors on the temperature rise at the pulpal dentin surface as well as in the bulk of the t-c&b during polymerization. Four t-c&bs (Luxatemp AM Plus, Protemp 3 Garant, Structur Premium, Trim) were used to fabricate flat cylindrical specimens (∅ 15.5mm) of different thicknesses (1, 2 and 4mm) using an over-impression placed on top of dentin discs (thickness 0.5, 1 and 2mm). Temperature was recorded at the pulpal dentin surface as well as inside the t-c&b (n=6). Data was subjected to parametric statistics (α=0.05). Peak temperatures inside the t-c&b varied between 37.0°C and 51.9°C and at the pulpal dentin side between 37.0°C and 50.6°C. The maximum temperatures registered depended significantly on the thickness of the dentin disc and t-c&b, respectively (ANOVA p<0.05). Peak temperatures were reached 2-3 min after start of mixing (dimethacrylates) and 6 min (mono-methacrylate), respectively, whereas Trim exhibited significantly higher peak temperatures (p<0.05). At 4mm layer thickness of the t-c&b, temperature rise may become critical if the material is not cooled properly. Composite-based t-c&bs showed significant lower curing temperatures than Trim and should therefore be preferred in daily practice. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Fracture resistance of the veneering on inlay-retained zirconia ceramic fixed partial dentures.

    PubMed

    Ohlmann, Brigitte; Gabbert, Olaf; Schmitter, Marc; Gilde, Herbert; Rammelsberg, Peter

    2005-11-01

    The aim of this in vitro study was to evaluate the fracture load of zircon frames veneered with a polymer glass holding box inlay-retained fixed partial dentures (FPDs). The influence of the position of the frame and the span length was tested. Additionally, the fracture load values of zircon frames veneered with a press ceramic were evaluated. Box inlay cavities were prepared on mandibular molars and premolars. Forty-eight FPDs were manufactured using industrially prefabricated zircon frames veneered with the polymer glass Artglass. Sixteen FPDs received individually manufactured CAD/CAM zircon frames veneered with a press ceramic. All FPDs underwent thermal cycling and mechanical loading (ML). The load to fracture was measured and fracture sites were evaluated. Four polymer veneered FPDs showed fractures in the veneering material after ML. The mean fracture resistance ranged from 531 N to 727 N. No significant influence of frame localization could be observed. Significantly greater fracture resistance values were found in the ceramic veneered FPDs (1276 N to 1413 N). There was no significant effect of span length in the polymer veneered group or in the all-ceramic group, with the exception of a significant peak in fracture load value for intermediate span lengths in the polymer group with a localized occlusal zircon frame. Polymer veneered FPDs with Y-TZP frames showed acceptable fracture resistance values, but they cannot yet be unreservedly recommended for clinical use. Fracture values for CAD/CAM manufactured Y-TZP frames combined with a press ceramic deserve further clinical investigation.

  13. Viscoelastic finite element analysis of an all-ceramic fixed partial denture.

    PubMed

    DeHoff, Paul H; Anusavice, Kenneth J; Götzen, Nils

    2006-01-01

    In recent years metal-free ceramic systems have become increasingly popular in dental practice because of their superior aesthetics, chemical durability and biocompatibility. Recently, manufacturers have proposed new dental ceramic systems that are advertised as being suitable for posterior fixed partial dentures (FPDs). Reports indicate that some of these systems have exhibited poor clinical performance. The objective of this study was to use the viscoelastic option of the ANSYS finite element program to calculate residual stresses in an all-ceramic FPD for four ceramic-ceramic combinations. A three-dimensional finite element model of the FPD was constructed from digitized scanning data and calculations were performed for four systems: (1) IPS Empress 2, a glass-veneering material, and Empress 2 core ceramic; (2) IPS Eris a low fusing fluorapatite-containing glass-veneering ceramic, and Empress 2 core ceramic; (3) IPS Empress 2 veneer and an experimental lithium-disilicate-based core ceramic; and (4) IPS Eris and an experimental lithium-disilicate-based core ceramic. The maximum residual tensile stresses in the veneer layer for these combinations are as follows: (1) 77 MPa, (2) 108 MPa, (3) 79 MPa, and (4) 100 MPa. These stresses are relatively high compared to the flexural strengths of these materials. In all cases, the maximum residual tensile stresses in the core frameworks were well below the flexural strengths of these materials. We conclude that the high residual tensile stresses in all-ceramic FPDs with a layering ceramic may place these systems in jeopardy of failure under occlusal loading in the oral cavity.

  14. Reliability and failure behavior of CAD-on fixed partial dentures.

    PubMed

    Basso, G R; Moraes, R R; Borba, M; Duan, Y; Griggs, J A; Della Bona, A

    2016-05-01

    To estimate the reliability and failure behavior of fixed partial dentures (FPDs) fabricated using the CAD-on technique. FPDs (n=25) were fabricated using a CAD/CAM system: IPS e.max ZirCAD - Crystall./Connect and IPS e.max CAD (Ivoclar). The restoration type ("three-unit bridge") and design method ("multilayer") based on Biogenerics were used. Framework and porcelain structures were united using a fusion ceramic (Crystall./Connect, Ivoclar). Mechanical fatigue was tested in a servohydraulic load frame machine at a cyclic loading (frequency: 2Hz; load ratio: 0.1). Based on previous data from specimens tested in fast fracture, three different stress profiles were used. The lifetime data were analyzed using an inverse power law-Weibull cumulative damage model (ALTA PRO, Reliasoft). All failed specimens were examined under a field emission scanning electron microscope. Porcelain chipping was the predominant (60%) mode of failure for FPDs tested in fast fracture and connector failure was predominant (67%) under fatigue. For fast fracture data, the Weibull modulus (β) of FPDs was 7.8 combining the two failure modes. When chipping and connector fracture data were analyzed separately, β values were 7.9 and 2.9. For the step stress fatigue test, β values were lower than estimated using fast fracture, being 1.6 for connector fracture and 1.3 for porcelain chipping. The test method (fast fracture or fatigue) significantly influenced the reliability of FPDs fabricated using the CAD-on technique, but it did not influence their failure behavior. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Effect of ceramic infrastructure on the failure behavior and stress distribution of fixed partial dentures.

    PubMed

    Borba, Márcia; Duan, Yuanyuan; Griggs, Jason A; Cesar, Paulo F; Della Bona, Álvaro

    2015-04-01

    The effect of the ceramic infrastructure (IS) on the failure behavior and stress distribution of fixed partial dentures (FPDs) was evaluated. Twenty FPDs with a connector cross-section of 16 mm(2) were produced for each IS and veneered with porcelain: (YZ) Vita In-Ceram YZ/Vita VM9 porcelain; (IZ) Vita In-Ceram Zirconia/Vita VM7 porcelain; (AL) Vita In-Ceram AL/Vita VM7 porcelain. Two experimental conditions were evaluated (n = 10). For control specimens, load was applied in the center of the pontic at 0.5 mm/min until failure, using a universal testing machine, in 37°C deionized water. For mechanical cycling (MC) specimens, FPDs were subjected to MC (2 Hz, 140 N, 10(6) cycles) and subsequently tested as described for the control group. For YZ, an extra group of 10 FPDs were built with a connector cross-section of 9 mm(2) and tested until failure. Fractography and FEA were performed. Data were analyzed by ANOVA and Tukey's test (α = 0.05). YZ16 showed the greatest fracture load mean value, followed by YZ16-MC. Specimens from groups YZ9, IZ16, IZ16-MC, AL16 and AL16-MC showed no significant difference for the fracture load. The failure behavior and stress distribution of FPDs was influenced by the type of IS. AL and IZ FPDs showed similar fracture load values but different failure modes and stress distribution. YZ showed the best mechanical behavior and may be considered the material of choice to produce posterior FPDs as it was possible to obtain a good mechanical performance even with a smaller connector dimension (9 mm(2)). Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Clinical performance and failures of zirconia-based fixed partial dentures: a review literature

    PubMed Central

    Triwatana, Premwara; Nagaviroj, Noppavan

    2012-01-01

    PURPOSE Zirconia has been used in clinical dentistry for approximately a decade, and there have been several reports regarding the clinical performance and survival rates of zirconia-based restorations. The aim of this article was to review the literatures published from 2000 to 2010 regarding the clinical performance and the causes of failure of zirconia fixed partial dentures (FPDs). MATERIALS AND METHODS An electronic search of English peer-reviewed dental literatures was performed through PubMed to obtain all the clinical studies focused on the performance of the zirconia FPDs. The electronic search was supplemented by manual searching through the references of the selected articles for possible inclusion of some articles. Randomized controlled clinical trials, longitudinal prospective and retrospective cohort studies were the focuses of this review. Articles that did not focus on the restoration of teeth using zirconia-based restorations were excluded from this review. RESULTS There have been three studies for the study of zirconia single crowns. The clinical outcome was satisfactory (acceptable) according to the CDA evaluation. There have been 14 studies for the study of zirconia FPDs. The survival rates of zirconia anterior and posterior FPDs ranged between 73.9% - 100% after 2 - 5 years. The causes of failure were veneer fracture, ceramic core fracture, abutment tooth fracture, secondary caries, and restoration dislodgment. CONCLUSION The overall performance of zirconia FPDs was satisfactory according to either USPHS criteria or CDA evaluations. Fracture resistance of core and veneering ceramics, bonding between core and veneering materials, and marginal discrepancy of zirconia-based restorations were discussed as the causes of failure. Because of its repeated occurrence in many studies, future researches are essentially required to clarify this problem and to reduce the fracture incident. PMID:22737311

  17. Minimally invasive preparation and design of a cantilevered, all-ceramic, resin-bonded, fixed partial denture in the esthetic zone: a case report and descriptive review.

    PubMed

    Barwacz, Christopher A; Hernandez, Marcela; Husemann, R Henry

    2014-01-01

    Resin-bonded, fixed partial dentures have the potential to offer a minimally invasive, fixed-prosthetic approach to tooth replacement in patients who may not be candidates for implant therapy. However, traditional preparation protocols often recommend extensive preparation designs on two abutment teeth, thereby potentially compromising the long-term health of the adjacent abutments and often resulting in unilateral debonding of one of the retainers in the long term. In light of advances in high-strength ceramic systems capable of being reliably bonded to tooth structure and offering improved esthetic outcomes, as well as clinical and case-series research demonstrating improved survivability of cantilevered resin-bonded fixed partial dentures, new preparation designs and methodologies can be advocated. The following case report demonstrates the clinical application of sonoabrasion, coupled with a dental operating microscope, to minimally prepare a single abutment for a cantilevered, all-ceramic resin-bonded fixed partial denture. Relevant historic and contemporary literature regarding double versus single-retainer resin-bonded fixed partial dentures are reviewed, as well as clinical conditions that are most favorable for such restorations to have an optimal long-term prognosis. If appropriate clinical conditions exist, a cantilevered, all-ceramic, resin-bonded, fixed partial denture may be the most conservative means of tooth replacement in a patient who is not a candidate for an endosseous implant. © 2013 Wiley Periodicals, Inc.

  18. In vitro Evaluation of the Accuracy of Seating Cast Metal Fixed Partial Denture on the Abutment Teeth with Varying Degree of Convergence Angle

    PubMed Central

    Tatikonda, Aravind; Raina, Seema; Gubrellay, Priyanka; Gupta, Naveen; Asopa, Swati Joshi

    2015-01-01

    Background The prime goal of a diligent prosthodontist is to obtain adequate marginal fit while restoring lost tooth structure. The marginal fit of the restoration, in turn depends upon the geometrical morphology of the tooth preparation. Objective To determine the effect of varying degree of convergence angle on the marginal seating of the single crown, three-unit fixed partial denture and multiple-unit fixed partial denture with pier abutment. Materials and Methods Three dies, of same convergence angle, were placed in an arch form on a base. In this way, four arch forms were prepared for four different convergence angles i.e. 0°, 6°, 12°, and 20°. Five castings each were made for single crown, 3-unit fixed partial denture and multiple-unit fixed partial denture (FPD) with pier abutment for each convergence angle. The castings were seated on their respective dies and vertical marginal discrepancy was measured at four points for each casting with the help of an optical microscope. Results The results showed that 200 convergence angle showed better marginal seating of the single crown, 3-unit FPD as well as for the multiple unit FPD. Conclusion There was a possibility that the retention and resistance may be compromised with 200 taper. Hence 120 taper is suggested for crowns and fixed partial denture retainers as the marginal discrepancy is reasonable and retention and resistance is optimum. There was a high statistical significant difference in the values obtained for the different convergence angles. PMID:26393207

  19. Total CAD/CAM Supported Method for Manufacturing Removable Complete Dentures

    PubMed Central

    Furtado de Mendonça, Mario; White, George Shelby; Sara, Georges; Littlefair, Darren

    2016-01-01

    The incorporation of computer-aided design/computer-aided manufacturing (CAD/CAM) technology into complete denture fabrication brings about several advantages to the fabrication process, providing better predictability of the desired outcomes and high accuracy of denture fit, mainly because the milling of prepolymerized acrylic resin eliminates the shrinkage of the acrylic base. Also, there is a decrease in the porosity when compared to a conventionally processed denture, and consequently there is a decrease in the retention of Candida albicans on the denture base. The presented workflow for complete denture fabrication presents a totally wax-free manufacturing process, combining rapid prototyping (RP) and rapid milling. With the presented technique, the maxillomandibular relation (MMR) and the ideal setup of the tooth arrangement are developed by using occlusion rims and trial setup made with RP. For the definitive final denture, the denture base and the basal surfaces of the conventional denture teeth were milled according to the individual clinical situation. Posteriorly, the teeth were adapted and bonded into the milled sockets of the milled base. PMID:27974977

  20. Usage of low-intensity laser radiation for the treatment of the inflammatory processes of the oral cavity mucosa after applying removable plate dentures

    NASA Astrophysics Data System (ADS)

    Kalivradzhiyan, Edvard; Lesnykh, Nikolay; Kunin, Vadim; Mutafyan, Mikhail

    1995-04-01

    Effective methods of reveling overload zones of the oral mucosa under the bases of plane dentures, the effect of low intensity laser radiation ont he increase of its resistance are discussed. At present removable plate dentures of different modifications to a certain degree restore aesthetic proportions of the face, phonetics and malfunction of the teeth and jaws. Besides, removable bridge are known not to secure even distribution of mastication pressure along the whole dentures bed which results in the development of inflammatory and dystrophic processes, and, finally in the accelerated atrophy of the oral mucosa and bony tissue of the alveolar process of upper and alveolar parts of the mandible. Many papers are devoted to the anti-inflammatory effect of laser therapy. Improvement of metabolic processes and revascularization of the dentures bed mucosa, normalization of the oral microflora structure, anesthetizing effect is noted too. At the same time there are no papers about studying the therapeutic effect of low intensity laser radiation intraumatic dentures stomatitis, inflammation of the oral mucosa in the literature available for us. To increase the functional effectiveness of removable plate dentures, profilaxy of inflammation and dystrophic phenomena and to decrease adaptation period we have developed methods of early detection of overload zone of oral mucosa at the initial stages of acute inflammation with the help of macrohistochemical reaction. Visible with the naked eye for the timely and precise correction of the dentures.

  1. In vitro evaluation of the flexural properties of All-on-Four provisional fixed denture base resin partially reinforced with fibers.

    PubMed

    Li, Bei Bei; Xu, Jia Bin; Cui, Hong Yan; Lin, Ye; Di, Ping

    2016-01-01

    The aim of this study was to assess the effects of partial carbon or glass fiber reinforcement on the flexural properties of All-on-Four provisional fixed denture base resin. The carbon or glass fibers were woven (3% by weight) together in three strands and twisted and tightened between the two abutments in a figure-of-"8" pattern. Four types of specimens were fabricated for the three-point loading test. The interface between the denture base resin and fibers was examined using scanning electron microscopy (SEM). Reinforcement with carbon or glass fibers between two abutments significantly increased the flexural strength and flexural modulus. SEM revealed relatively continuous contact between the fibers and acrylic resin. The addition of carbon or glass fibers between two abutments placed on All-on-Four provisional fixed denture base resin may be clinically effective in preventing All-on-Four denture fracture and can provide several advantages for clinical use.

  2. Risk factors associated with denture stomatitis in the United States.

    PubMed

    Shulman, J D; Rivera-Hidalgo, F; Beach, M M

    2005-07-01

    This study reports denture stomatitis (DS) prevalence from a large USA probability sample from the National Health and Nutrition Examination Survey, 1988-1994 (NHANES III). Oral examinations were performed on 3450 individuals 18-90+ years of age (mean: 59.2; SD: 0.50 years), 57.7% male and 42.3% female. Multivariable logistic regression models were fitted for DS using sociodemographic, denture quality, blood analytes, alcohol and tobacco use, history of diabetes, and current antibiotic use as covariates. Odds ratios (OR), adjusted for other covariates in each model (AOR) are presented. Of 3450 removable denture wearers, 963 (27.9%) had DS. DS prevalence was associated with wearing maxillary (AOR: 6.20) and mandibular (AOR: 5.21) complete dentures continuously; smoking >/=15 cigarettes day (maxillary complete: AOR = 1.31; mandibular complete: AOR = 1.50; maxillary partial: AOR = 2.04); vitamin A deficiency (mandibular complete: AOR = 5.97; maxillary partial: AOR = 5.67; mandibular partial: AOR = 24.42). Maxillary dentures with inadequate relines had approximately half the OR of DS than those with adequate relines (maxillary complete: AOR = 0.42; mandibular complete: AOR = 0.50). Denture stomatitis prevalence is associated with the amount of tissue covered by dentures, low vitamin A levels, cigarette smoking, and constant denture wear.

  3. The U-Beam bridge: an advancement in the fiber-reinforced resin-bonded fixed partial denture.

    PubMed

    Rada, Robert; Cruz Gonzalez, Wanda I

    2009-01-01

    Conservative, esthetic restorative dentistry has become an essential component in modern clinical dental practice. This article reviews the literature regarding the fiber-reinforced resin-bonded fixed partial dentures. A clinical case illustrates the technique. The main supportive framework is a U-beam and reinforcing rod composed of unidirectional, pretensed quartz fibers bound in an epoxy resin matrix. This composite resin restoration is ideal as an interim solution when an implant is being considered for placement in the undetermined future or as a medium to long-term restoration in certain clinical cases where occlusal forces are controlled and the abutment teeth in good health.

  4. The effect of incorporation, orientation and silane treatment of glass fibers on the fracture resistance of interim fixed partial dentures.

    PubMed

    Basant, Gupta; Reddy, Y G

    2011-03-01

    Fracture of interim fixed partial dentures (FPD) is of important concern to the dental surgeon, especially with long-span fixed partial dentures or areas of heavy occlusal stress. Polymers used in interim FPDs, reinforced with glass fibers have shown to have a positive effect on the fracture resistance of interim FPDs. Since little research has been done on the influence of silane treated glass fibers on the fracture resistance of interim FPDs, this study was conducted to evaluate the effect of silane treatment of glass fibers on the fracture resistance of interim FPDs and its correlation with the position of fiber reinforcement and length of the span of the interim FPD. Interim FPDs were fabricated from an autopolymerizing polymethyl methacrylate (PMMA) resin. Seven FPDs were made in each group. The FPDs in the control group were unreinforced, and in the other groups the FPDs were reinforced either with non silane treated glass fiber or with silane treated glass fiber. The fibers were placed in two different locations in the FPDs. Three length of span of FPDs were tested. The load was applied to the FPD by a steel ball placed in the center of the pontic space. One Way Anova, Two Way Anova, Studentized range test (Scheffe's). Results showed that the load required for fracturing the unreinforced FPDs varied from 272 to 998 N. Mean fracture load of reinforced FPDs varied from 536 to 1642 N. One-way analysis of variance showed that the position of fibers and the silane treatment fibers significantly affected the fracture load. The results of this study suggested that the silane treatment of glass fibers had a marked improvement in the fracture resistance of FPDs as compared to untreated glass fibers. Selective placement of the glass fibers at the undersurface of the pontic and the occlusal surface of the interim fixed partial denture showed more increase in the fracture resistance as compared to the randomly distributed glass fibers. The glass fiber reinforcement is

  5. The combination of a nylon and traditional partial removable dental prosthesis for improved esthetics: a clinical report.

    PubMed

    Ito, Masayasu; Wee, Alvin G; Miyamoto, Takanari; Kawai, Yasuhiko

    2013-01-01

    A benefit of a nylon partial removable dental prosthesis (PRDP) is the absence of a metal framework, providing improved esthetics. Unfortunately, the lack of a traditional framework reduces rigidity and the support of occlusal rests. This clinical report describes a combination of a nylon PRDP (polyamide denture base resin) and a traditional PRDP (framework/resin) for a Kennedy Class II, Modification 1, partially edentulous mandible. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  6. Three-dimensional finite element stress analysis: the technique and methodology of non-linear property simulation and soft tissue loading behavior for different partial denture designs.

    PubMed

    Kanbara, Ryo; Nakamura, Yoshinori; Ochiai, Kent T; Kawai, Tatsushi; Tanaka, Yoshinobu

    2012-01-01

    The purpose of this study was to develop and report upon a methodology for a non-linear capacity 3D modeling finite element analysis evaluating the loading behavior of different partial denture designs. A 3D finite element model using human CT data was constructed. An original material constant conversion program was implemented in the data simulation of non-linear tissue behavior. The finite element method material properties of residual ridge mucosa were found to have seven material constants and six conversion points of stress values. Periodontal tissues were found to have three constants, and two conversion points. Three magnetic attachment partial denture designs with different bracing elements were evaluated. Technical procedures for finite element model simulation of nonlinear tissue behavior properties evaluating the oral behavior of prosthetic device designs are reported for prosthodontic testing. The use of horizontal cross-arch bracing positively impacts upon the comparative stability of the partial denture designs tested.

  7. Comparative Evaluation of Marginal Accuracy of a Cast Fixed Partial Denture Compared to Soldered Fixed Partial Denture Made of Two Different Base Metal Alloys and Casting Techniques: An In vitro Study.

    PubMed

    Jei, J Brintha; Mohan, Jayashree

    2014-03-01

    The periodontal health of abutment teeth and the durability of fixed partial denture depends on the marginal adaptation of the prosthesis. Any discrepancy in the marginal area leads to dissolution of luting agent and plaque accumulation. This study was done with the aim of evaluating the accuracy of marginal fit of four unit crown and bridge made up of Ni-Cr and Cr-Co alloys under induction and centrifugal casting. They were compared to cast fixed partial denture (FPD) and soldered FPD. For the purpose of this study a metal model was fabricated. A total of 40 samples (4-unit crown and bridge) were prepared in which 20 Cr-Co samples and 20 Ni-Cr samples were fabricated. Within these 20 samples of each group 10 samples were prepared by induction casting technique and other 10 samples with centrifugal casting technique. The cast FPD samples obtained were seated on the model and the samples were then measured with travelling microscope having precision of 0.001 cm. Sectioning of samples was done between the two pontics and measurements were made, then the soldering was made with torch soldering unit. The marginal discrepancy of soldered samples was measured and all findings were statistically analysed. The results revealed minimal marginal discrepancy with Cr-Co samples when compared to Ni-Cr samples done under induction casting technique. When compared to cast FPD samples, the soldered group showed reduced marginal discrepancy.

  8. Effect of connector design on the fracture resistance of all-ceramic fixed partial dentures.

    PubMed

    Oh, Won-Suck; Anusavice, Kenneth J

    2002-05-01

    Fracture of all-ceramic fixed partial dentures (FPDs) tends to occur in the connector area. The objective of this study was to test the hypothesis that the radii of curvature at the connector affects the fracture resistance of 3-unit FPDs. With the use of a standardized silicone mold, 40 three-unit FPD wax patterns were fabricated with the same dimensions and divided into 4 groups of 10 specimens per group. Each pattern was modified at the connector areas of the occlusal embrasure (OE) and the gingival embrasure (GE); 2 wax carvers with radii of curvature at their tips of 0.90 mm and 0.25 mm were used. The dimensions of the connectors were standardized with an electronic caliper to 4 +/- 0.12 mm in height and 5 +/- 0.13 mm in width. Connector designs were as follows: Design I: OE and GE 0.90 mm; Design II: OE 0.90 mm and GE 0.25 mm; Design III: OE 0.25 mm and GE 0.90 mm; and Design IV (control): OE and GE 0.25 mm. An experimental hot-pressed core ceramic was used to make the FPD frameworks, which were consequently cemented on epoxy dies with dual-polymerizing composite (Variolink II) and loaded to fracture in a universal testing machine at a crosshead speed of 0.5 mm/min. The failure load data were analyzed with analysis of variance (ANOVA; P=.05) and Duncan's test (alpha=.01). The mean failure loads and standard deviations were as follows: 943 +/- 151 N for Design I; 746 +/- 106 N for Design II; 944 +/- 144 N for Design III; and 673 +/- 55 N for Design IV. ANOVA revealed a significant difference (P< or = .0001) between the mean failure loads of different connector designs. The mean loads to failure for Designs I and III were significantly higher than those for Designs II and IV (Duncan's test). Within the limitations of this study and for the experimental ceramic tested, as the radius at the gingival embrasure increased from 0.25 to 0.90 mm, the mean failure load increased by 140%. The radius of curvature at the occlusal embrasure had only a minor effect on the

  9. Evaluation of bone loss at single-stage and two-stage implant abutments of fixed partial dentures.

    PubMed

    Koczorowski, R; Surdacka, A

    2006-01-01

    Fixed partial dentures (FPDs) can be supported on implant abutments only or on single-stage and two-stage implants and teeth. The purpose of this study was a comparative analysis of bone loss at the single-stage and two-stage implant abutments of fixed partial dentures used to restore missing teeth classified as Class I or Class II according to the Kennedy classification. 32 patients were treated by using 49 FPDs supported on implants and teeth worn for 2-6 years. Bone loss at the implant abutments of FPDs was evaluated by one examiner using a special ruler with a measuring scale and images of implants. Measurements were conducted at 26 single-stage implants and 50 two-stage implant abutments based on panoramic radiographs. Statistical analysis showed that the mean bone loss at implants after 2 years was 0.70 mm +/- 0.50. The mean bone loss at implants after 6 years was 1.73 mm +/- 0.41. The bone loss of the alveolar ridge at the single-stage implants was greater than at the two-stage implants but it was not statistically significant. Prosthetic treatment of missing teeth classified as Class I or II according to the Kennedy classification with FPDs may result in bone loss less than 2 mm after 6 years. Both single-stage and two-stage intraosseous implants can be suitable for the implant-prosthetic treatment of patients with alar lack of teeth.

  10. Cost-effectiveness of endodontic molar retreatment compared with fixed partial dentures and single-tooth implant alternatives.

    PubMed

    Kim, Sahng G; Solomon, Charles

    2011-03-01

    One of the most challenging situations in dentistry is a failed root canal treatment case. Should a failed root canal-treated tooth be retreated nonsurgically or surgically, or should the tooth be extracted and replaced with an implant-supported restoration or fixed partial denture? These four treatment alternatives were compared from the perspective of cost-effectiveness on the basis of the current best available evidence. The costs of the four major treatment modalities were calculated using the national fee averages from the 2009 American Dental Association survey of dental fees. The outcome data of all treatment modalities were retrieved from meta-analyses after electronic and manual searches were undertaken in the database from MEDLINE, Cochrane, ISI Web of Knowledge, and Scopus up to April 2010. The treatment strategy model was built and run with TreeAge decision analysis software (TreeAge Software, Inc, Williamstown, MA). Endodontic microsurgery was the most cost-effective approach followed by nonsurgical retreatment and crown, then extraction and fixed partial denture, and finally extraction and single implant-supported restoration. The cost-effectiveness analysis showed that endodontic microsurgery was the most cost-effective among all the treatment modalities for a failed endodontically treated first molar. A single implant-supported restoration, despite its high survival rate, was shown to be the least cost-effective treatment option based on current fees. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Two-year clinical evaluation of lithia-disilicate-based all-ceramic crowns and fixed partial dentures.

    PubMed

    Taskonak, Burak; Sertgöz, Atilla

    2006-11-01

    The aim of this study was to evaluate the clinical performance of crowns and fixed partial dentures (FPDs) made with the Empress 2 system over a 2-year period. Twenty anterior or posterior all-ceramic (Empress 2) crowns and 20 anterior or posterior, three-unit fixed partial dentures were fabricated for 15 patients. Evaluations of the restorations were performed at baseline and once a year during the 2-year follow-up period. U.S. Public Health Service criteria were used to examine the marginal adaptation, color match, secondary caries and visible fractures in the restorations. Survival rate of the restorations were determined using Kaplan-Meier statistical analysis. U.S. Public Health Service criteria showed 100% Alpha scores concerning recurrent caries for both crowns and FPDs. No crown fractures were observed during the 2-year follow-up, however, 10 (50%) catastrophic failures of FPDs occurred. Five (25%) failures occurred within the 1-year clinical period and the others (25%) within the second year. Single unit Empress 2 all-ceramic crowns exhibited a satisfactory clinical performance over 2-year period. Furthermore, the high fracture rate of Empress 2 FPDs limits the usage of Empress 2 for the fabrication of all-ceramic FPD.

  12. [Statistical study of 41 cases with denture foreign bodies in the air and food passages and significance of the duplicated denture model].

    PubMed

    Abe, T; Tsuiki, T; Murai, K; Sasamori, S

    1990-12-01

    A statistical study of 41 cases with denture foreign bodies in the air and upper food passages which were treated in our department during the past 21 years was done. (1) Males were more frequently affected. The ratio of male to female was about 2 to 1. (2) Of 41 dentures, 2, 2 and 37 were lodged in the air passages, hypopharynx and esophagus respectively. (3) There were 5 complete mandibular dentures in 41 cases. (4) The causes of the denture foreign bodies were originated to the problem of denture itself in 29 cases, that of the patient himself in 2 cases and both in 10 cases. (5) Of 39 problematic dentures, 16 showed the breakage such as plate fracture and clasp deformity, but the other 23 showed no breakage. In this latter group, poor holding of the denture was ascribed to miss-making or miss-planning. (6) Of 12 patients with problems in their physical function, 5 had suffered from cerebrovascular disease and 3 from geriatric dementia. (7) The denture foreign body in aged patients with physical hypofunction tends to increase in recent years. (8) Of 39 dentures tried to remove by esophagoscopy, 18 were done with difficulty and they were detachable partial dentures with one artificial tooth and 2-arm-clasps lodged at the first and/or second isthmus of the esophagus. Though we have a denture removed successfully at the third trial, we have no case needed external esophagotomy. (9) Duplicated denture models were made in 20 cases prior to the procedure, and we certify that these models play an important role for the safer removal of denture foreign bodies.

  13. [Neutral zone. An anatomic space which is often neglected while fabricating removable complete dentures].

    PubMed

    van Waas, M A J

    2011-11-01

    When designing complete dentures, consideration should not only be given to the occlusal concept but also to the occlusal system as a whole. An important part of that system is the position of the artificial teeth. This prosthetic part of the occlusal system is directly related to the tongue, the floor of the mouth, the cheeks and the lips. The artificial teeth of the mandibular dentures have to be positioned in the so-called 'neutral zone' of the edentulous mandible. The neutral zone is the stress-free area between the tongue on one side and, on the other side, the mimic muscles, which are responsible for the movement of the lips and cheeks. Moreover, the maxillary posterior artificial teeth and the supporting acrylic surfaces of the maxillary denture have an important function in providing support for the upper lip and cheeks in order to prevent a 'denture look' appearance.

  14. Treating severe partial anodontia: a 10-year history of patient treatment.

    PubMed

    Dario, L J; Aschaffenburg, P H

    1994-12-01

    Severe partial anodontia is relatively rare. This case report describes the 10-year treatment history of a patient with partial anodontia, beginning with removable partial overlay dentures and culminating with fixed implant prostheses.

  15. Effects of mouth rehabilitation with removable complete dentures on stimulus perception and the electromyographic activity of the orbicularis oris muscle.

    PubMed

    de Caxias, Fernanda P; Dos Santos, Daniela M; Goiato, Marcelo C; Bitencourt, Sandro B; da Silva, Emily V F; Laurindo-Junior, Murilo C B; Turcio, Karina H L

    2017-09-26

    Many elderly individuals are rehabilitated with removable complete dentures, which require an initial adaptation period for both oral perception and the perioral muscles. Studies assessing the changes in stimulus perception and the electromyographic (EMG) activity of the orbicularis oris muscle shortly after conventional complete denture insertion are lacking. The purpose of this clinical study was to evaluate the effect of mouth rehabilitation with removable complete dentures on stimulus perception and the EMG activity of the orbicularis oris muscle. This study was approved by the Human Research Ethics Committee of the Araçatuba Dental School (São Paulo State University). Fifteen participants who had worn their removable complete dentures for at least 5 years and needed rehabilitation with new prostheses were enrolled in the study. A perception questionnaire was applied, and surface EMG examinations of the orbicularis oris muscle during rest, suction of water with a straw, and pronunciation of the syllables /bah/, /mah/, /pah/, and the word 'Mississippi' were performed before (T0) and 30 (T1) and 100 (T2) days after insertion of the new prostheses. The data were analyzed with the Cochran Q test, McNemar test, 2-way repeated measures ANOVA, and honestly significant difference (HSD) Tukey test (α=.05). Significant improvement was reported in the perception questionnaire in terms of the oral discomfort sensation in the T2 period. EMG activity decreased during rest and suction after insertion of the new prostheses. A statistical difference between the upper and lower fascicles of the orbicularis oris muscle was detected, with a decrease of EMG activity between the T0 and T1 periods on the lower fascicle, except for when pronouncing the /pah/ syllable. Mouth rehabilitation with removable complete dentures decreased oral discomfort and, depending on the oral function, decreased or increased EMG activity of the orbicularis oris muscle. In addition, the lower fascicle

  16. An Ingenious Modification in Conventional Swing Lock Cast Partial Denture for Rehabilitating A Hemi Mandibulectomy Defect

    PubMed Central

    Shah, Rupal Jaydip; Lagdive, Sanjay Balaji; Saini, Shraddha Lalit; Shah, Satyaprakash Ranjit

    2017-01-01

    Mandibular resections compromise the balance and symmetry of mandibular functions. Since centuries there has been advent of various prosthetic treatment modalities to improve the masticatory efficiency. Swing lock dentures, a treatment facet with high degree of clinical effectiveness, yet gradually fading into oblivion due to its design complexities, has been resurrected by retaining its indigenous concept of reciprocation, and consolidating aesthetics with introduction of newer breed of aesthetic material (Thermoplastic Acetal resin). PMID:28274062

  17. Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture.

    PubMed

    Jain, Ashish R; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew

    2013-04-01

    A hybrid denture is one that is fabricated over a metal framework and retained by screws threaded into the implant abutments. The anterior part of a mandibular hybrid denture is fixed on implants while the posterior part of the denture is extended and cantilevered from implants. This article presents the fabrication of a maxillary over-denture opposing mandibular implant retained hybrid prosthesis. A total of four implants were placed in the mandibular arch. Castable abutments were used to produce the optimal angulations. Framework was waxed, cast recovered, and the fit was refined until the framework seated passively on the master cast. The mandibular denture teeth were waxed to the hybrid framework, and a final wax try-in was performed to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verification of occlusion, retention, and stability. The rehabilitation of edentulous patients with hybrid dentures has been observed to achieve greater masticatory function and psychological satisfaction than with conventional over-dentures. Producing a passive-fitting substructure for a fixed removable screw retained hybrid prosthesis is arguably one of the most technically complex tasks in implant dentistry. The technique presented may not initially produce a perfectly passive framework, but use of disclosing media and adjusting the internal aspect of the casting can result in non-binding, fully seated prostheses.

  18. Oral rehabilitation with implant-supported fixed partial dentures in periodontitis-susceptible subjects. A 5-year prospective study.

    PubMed

    Wennström, Jan L; Ekestubbe, Annika; Gröndahl, Kerstin; Karlsson, Stig; Lindhe, Jan

    2004-09-01

    Comparatively few studies with at least 5 years of follow-up are available that describe the use of implants in prosthetic rehabilitation of partially edentulous patients. Randomized, controlled clinical studies that evaluated the effect of different surface designs of screw-shaped implants on the outcome of treatment are also sparse. To determine, in a prospective randomized, controlled clinical trial, the outcome of restorative therapy in periodontitis-susceptible patients who, following basic periodontal therapy, had been restored with implants with either a machined- or a rough-surface topography. Fifty-one subjects (mean age, 59.5 years), 20 males and 31 females who, following treatment of moderate-to-advanced chronic periodontitis, required implant therapy for prosthetic rehabilitation were recruited. Seventeen of the patients were current smokers. Following the active treatment, all subjects were included in an individually designed maintenance program. A total of 56 fixed partial dentures (FPDs) and a total of 149 screw-shaped, and self-tapping implants (Astra Tech implants) -- 83 in the maxilla and 66 in the mandible -- were installed in a two-stage procedure. Each patient received a minimum of two implants and by randomization every second implant that was installed had been designed with a machined surface and the remaining with a roughened Tioblast surface. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographical examinations were performed following FPD connection and once a year during a 5-year follow-up period. The analysis of peri-implant bone-level alterations was performed on subject, FPD and implant levels. Four patients and four FPDs were lost to the 5 years of monitoring. One implant (machined surface) did not properly integrate (early failure), and was removed at the time of abutment connection. Three implants were lost during function and a further eight implants could not be accounted for at the 5

  19. Effects of mechanical properties of adhesive resin cements on stress distribution in fiber-reinforced composite adhesive fixed partial dentures.

    PubMed

    Yokoyama, Daiichiro; Shinya, Akikazu; Gomi, Harunori; Vallittu, Pekka K; Shinya, Akiyoshi

    2012-01-01

    Using finite element analysis (FEA), this study investigated the effects of the mechanical properties of adhesive resin cements on stress distributions in fiber-reinforced resin composite (FRC) adhesive fixed partial dentures (AFPDs). Two adhesive resin cements were compared: Super-Bond C&B and Panavia Fluoro Cement. The AFPD consisted of a pontic to replace a maxillary right lateral incisor and retainers on a maxillary central incisor and canine. FRC framework was made of isotropic, continuous, unidirectional E-glass fibers. Maximum principal stresses were calculated using finite element method (FEM). Test results revealed that differences in the mechanical properties of adhesive resin cements led to different stress distributions at the cement interfaces between AFPD and abutment teeth. Clinical implication of these findings suggested that the safety and longevity of an AFPD depended on choosing an adhesive resin cement with the appropriate mechanical properties.

  20. The all-ceramic, inlay supported fixed partial denture. Part 3. Experimental approach for validating the finite element analysis.

    PubMed

    Thompson, M C; Field, C J; Swain, M V

    2012-03-01

    In a previous study, the authors used a finite element analysis (FEA) to evaluate the stresses developed during the loading of an all-ceramic, inlay supported fixed partial denture and compared it with the more traditional full crown supported prosthesis. To date there has been little research into correlating the responses of the numerical model against physical mechanical tests; such validation analysis is crucial if the results from the FEA are to be confidently relied upon. This study reports on the experimental methods used to compare with the FEA and thereby to validate the predictive fracture behaviour of the numerical model. This study also outlines the methods for manufacture and testing of the ceramic structure along with observations of the fracture tests. In addition the procedure used for developing the FEA model for the test system is outlined.

  1. Magnetic denture retention systems: inexpensive and efficient.

    PubMed

    Gillings, B R

    1984-09-01

    A magnetic retention system has been used in more than 6000 complete and partial overdentures, sectional dentures and implant overdentures, with excellent clinical results and patient acceptability. For the overdenture application, decoronated, root-treated teeth are fitted with preformed or cast magnetisable alloy root elements, or 'keepers'. Following conventional denture construction, paired cobalt/samarium magnets in a special configuration are cured into the denture base so that with the denture inserted, the magnets grip the root elements with a retentive force of approximately 300 g per root. The paired magnet arrangement eliminates any external magnetic field and doubles the available retention. Magnetic retention has few of the problems encountered with other retention devices. It offers simplicity, low cost, self-adjustment, inherent stress-breaking, automatic repositioning after denture displacement, comparative freedom of lateral denture movement, reduces trauma to retained roots and eliminates the need for adjustment in service. For the sectional denture application, undesirable undercuts on the abutment teeth are used to provide passive, positive retention. The separate buccal and lingual sections are joined together by parallel pins fitting into matching tubes, assembly being maintained by magnetic attraction between a retention element in one section and a keeper in the other. Insertion and removal are more difficult than with a conventional denture but soft tissue coverage is minimal. There are no visible retainer arms and food traps are eliminated. Abutment tooth preparation is negligible, the laboratory procedures simple, and the treatment inexpensive and reversible. A clinical trial of magnetic overdenture retention in conjunction with osseointegrated titanium implants is now in progress. After 21 months acceptable clinical results have been obtained. An improved implant with an alumina core and a sintered hydroxyapatite coating is at present

  2. Does wearing dentures change sensory nerve responses under the denture base?

    PubMed

    Ito, Nana; Kimoto, Suguru; Kawai, Yasuhiko

    2014-03-01

    The standard textbook on complete dentures suggests the necessity of relief for the incisive and posterior palatine foramina of denture wearers to prevent the impingement of the nerves and vessels passing through these foramina. However, concrete evidence of the effect of dentures on the sensory function of the nerves underlying dentures is lacking. The study aim was to investigate the influence of denture-induced compression on sensory nerve responses to stimulations. Only partially edentulous patients of maxillary Kennedy class II who wear dentures (WD) or who never wear dentures (ND) were recruited as participants. The WD and ND groups had 15 participants with a mean age of 66.9 years and 22 participants with a mean age of 60.2 years, respectively. Current perception thresholds (CPTs) at 2000, 250 and 5 Hz, corresponding to A-beta, A-delta and C fibres, respectively, were measured by the Neurometer(®) NS3000 device and compared between groups. The data were analysed by the t-test, the paired t-test and analysis of covariance adjusted for age, sex and thickness of the mucosa. The CPTs showed large differences at 2000 Hz but no differences at the other frequencies when the WD and ND groups were compared. Only the CPT of the edentulous side at 2000 Hz was significantly different between groups. Wearing removable partial dentures contributes to changes of responses to stimulations in the large fibre of the sensory nerve underlying the maxillary alveolar ridge. © 2012 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  3. Computer-assisted generation of all-ceramic crowns and fixed partial dentures.

    PubMed

    Besimo, C E; Spielmann, H P; Rohner, H P

    2001-10-01

    The successful application of the concept of computer-assisted manufacturing in restorative dentistry requires that computer-assisted design (CAD) and computer-assisted machining (CAM) not only meet but actually exceed currently accepted standards for the material and clinical quality of dental restorations. In addition, the continued development of systems for polyvalent processing of disparate materials and objects must be assured. With these critical requirements in mind, the Precident system is a clinically proven and competitive system. The resolving power of the CCD chip is much improved compared to conventional cameras or charge-coupled devices. The scanner is able to scan entire casts in a fully automated process. In principle, this facilitates the production of frameworks for fixed prosthetic devices (FPD) of any size. It is also possible to create at least partial frameworks for removable prosthetic devices (RPD). A factor of great clinical and economic importance is the polyvalence of the process in materials processing: the numeric control (NC) machine can be programmed for metal alloys and ceramic materials as well as fiber-reinforced resins. At Aeskulap Klinik, the Precident System is routinely used for producing all single crowns and FPDs with up to four units. CAD/CAM all-ceramic crowns and FPDs currently cost about the same as metallo-ceramic or conventional all-ceramic restorations.

  4. A laboratory investigation of the role of guide planes in the retention of cast cobalt-chromium alloy partial denture frameworks.

    PubMed

    Ali, M; Waters, N E; Nairn, R I; West, F; Sherriff, M

    2001-05-01

    This in vitro study examined the resistance to displacement offered by guide planes and the displacement mechanics of a bilateral bounded saddle cast cobalt chrome alloy removable partial denture framework under conditions simulating an average initial fit. A specially designed model mouth jig fitted with strain gauges to monitor the forces across the guiding plane/guiding surface interfaces was used. Guiding planes of enamel, silver tin amalgam and dental composite with seven combinations of guide planes and three angles of withdrawal were examined. Guiding plane size was also examined for dental enamel. A statistically significant difference in retention was found for all factors examined. Retention increased with increasing angle of withdrawal. Size effects were found but considered unreliable. It was concluded that with a tight fit guiding plane retention may be readily predicted for any given material, combination of mesial, distal and lingual guiding planes and angulation conditions by the application of mechanical principles providing the basic parameters are known. Attention is drawn to the reasons for further work to fully understand the clinical situation.

  5. Three-dimensional finite element analysis of zirconia all-ceramic cantilevered fixed partial dentures with different framework designs.

    PubMed

    Miura, Shoko; Kasahara, Shin; Yamauchi, Shinobu; Egusa, Hiroshi

    2017-06-01

    The purpose of this study were: to perform stress analyses using three-dimensional finite element analysis methods; to analyze the mechanical stress of different framework designs; and to investigate framework designs that will provide for the long-term stability of both cantilevered fixed partial dentures (FPDs) and abutment teeth. An analysis model was prepared for three units of cantilevered FPDs that assume a missing mandibular first molar. Four types of framework design (Design 1, basic type; Design 2, framework width expanded buccolingually by 2 mm; Design 3, framework height expanded by 0.5 mm to the occlusal surface side from the end abutment to the connector area; and Design 4, a combination of Designs 2 and 3) were created. Two types of framework material (yttrium-oxide partially stabilized zirconia and a high precious noble metal gold alloy) and two types of abutment material (dentin and brass) were used. In the framework designs, Design 1 exhibited the highest maximum principal stress value for both zirconia and gold alloy. In the abutment tooth, Design 3 exhibited the highest maximum principal stress value for all abutment teeth. In the present study, Design 4 (the design with expanded framework height and framework width) could contribute to preventing the concentration of stress and protecting abutment teeth. © 2017 Eur J Oral Sci.

  6. Relationship between oral function and occlusal support in denture wearers.

    PubMed

    Yamashita, S; Sakai, S; Hatch, J P; Rugh, J D

    2000-10-01

    Patients with removable partial dentures or complete dentures do not demonstrate masticatory function to the same level as patients with a full set of natural teeth. The purpose of this study was to characterize the relationship between reduction of masticatory function, in terms of masticatory performance and bite force, and the existence of remaining natural occlusal supports as assessed by the Eichner index. One hundred and eighteen removable partial denture and complete denture wearers were selected for analyses. These subjects were divided into four groups depending upon the number of occlusal supports. Seventy dentate subjects with full occlusal support were designated as a comparison group. Bilateral bite force was measured at the first molar region in all subjects. Masticatory performance was assessed using the modified Masticatory Performance Index. Peanuts were used as the test food. Both bite force and masticatory performance were significantly associated with group classification. Moreover, both bite force and masticatory performance of the four denture groups were significantly reduced compared to the comparison group and this tendency was remarkable for the denture groups without occlusal support. These results suggest that the existence of functional tooth units may be a key factor in preservation of masticatory function.

  7. Using CAD/CAM technology to create a 10-unit zirconia fixed partial denture--a UTHSCSA dental school case report.

    PubMed

    Zimmermann, Richard; Seitz, Stefanie; Magness, Brent; Wieck, Blaine

    2013-10-01

    From diagnosis and treatment planning to the materials being used, technology is changing dentistry. New materials are providing dentists greater options for treatment, while technology is streamlining the workflow in the office and dental laboratory. Traditionally the creation of a long-span fixed partial denture was a labor intense project--from waxing up the prosthesis--to stacking of the porecelain. For larger frameworks, it was recommended for the dentist to bring in the patient in for a framework try-in. However, advances in both CAD/CAM technology and dental materials are revolutionizing the way dentistry is being done. The following describes the fabrication of a 10-unit full contour zirconia fixed partial denture completed in the pre-doctorate program at UTHSCSA Dental School.

  8. Effect of masticatory load on crack deflection/penetration investigated with en-face optical coherence tomography in ceramic fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Marsavina, Liviu; Negru, Radu; Hluscu, Mihai; Caplescu, Cristiana; Bradu, Adrian; Hughes, Michael; Rominu, Mihai; Podoleanu, Adrian Gh.

    2009-02-01

    Optical Coherence Tomography (OCT) allows a better characterization of dental prostheses. The detection of substance defects within the ceramic layers for metal-ceramic prostheses was demonstrated. The detected defects have a large volume and therefore there is a high likelihood for fracture lines to be generated in the proximal areas of the ceramic fixed partial dentures. If the detection of such defects is feasible before inserting the prosthesis into the oral cavity, then timely corrective measures are possible in order to avoid the fracture of the ceramic component later on. After noninvasive localization of cracks in ceramic fixed partial dentures, the effect of the biaxial loading on crack deflection/penetration at the ceramic interface was investigated. A biaxial loaded geometry was numerically investigated using Finite Element Analysis in order to determine the energy release rate. The obtained results could be used in conjunction with criteria at interface for estimating the path of the crack after the interface was reached.

  9. Marginal adaptation of inlay-retained adhesive fixed partial dentures after mechanical and thermal stress: an in vitro study.

    PubMed

    Göehring, T N; Peters, O A; Lutz, F

    2001-07-01

    There are no studies that analyze the long-term durability of minimally invasive fixed partial dentures (FPDs) by comparing different methods of adhesive bonding. This in vitro study examined the influence of cavity design and operative technique on the marginal adaptation of resin-bonded composite FPDs. Slot-inlay tooth preparations with cavity margins located in enamel were prepared in 18 maxillary canines and 18 maxillary first molars designated as abutments. The specimens were divided equally into 3 experimental groups. In all groups, butt joint tooth preparations were created in canines and molars. In group 2, canines were prepared additionally with a 1.5-mm wide palatal bevel in enamel. After pretests with modification spaces of 11 and 17 mm (length), 2 missing premolars were replaced by the ceromer Targis and reinforced with the glass-fiber material Vectris. The prostheses were inserted with Tetric Ceram with use of an ultrasonic-supported, high-viscosity technique. Restorations were selectively bonded to cavity finish lines in groups 1 and 2 ("selective bonding"). In group 3, restorations were bonded totally to the whole cavity surface ("total bonding"). The restorations were stressed in a computer-controlled masticator. Marginal quality was examined with an SEM at x 200. The percent area of optimal margins after thermomechanical loading between composite and enamel in each group was as follows: group 1, 86.2% +/- 12.3% for canines and 95.5% +/- 3.5% for molars; group 2, 95.3% +/- 2.1% for canines and 96.2% +/- 2.7% for molars; and group 3, 95% +/- 0.9% for canines and 86.4% +/- 3.2% for molars. The marginal quality for molars inserted with total bonding was significantly lower (P< or =.05). Within the limitations of this study, the selective bonding technique for slot inlay-retained fixed partial dentures resulted in a negligible loss of marginal quality after extensive mechanical and thermal stress. The selective bonding technique is recommended for box

  10. Load-bearing capacity of all-ceramic posterior four-unit fixed partial dentures with different zirconia frameworks.

    PubMed

    Kohorst, Philipp; Herzog, Timo J; Borchers, Lothar; Stiesch-Scholz, Meike

    2007-04-01

    The aim of this in vitro study was to compare the load-bearing capacity of posterior four-unit fixed partial dentures (FPDs) produced with two different yttria-stabilized polycrystalline tetragonal zirconia (Y-TZP) ceramics, one being a presintered material, the other a fully sintered, hot isostatically pressed material. Additionally, as a novel approach, the influence of preliminary mechanical damage upon the fracture force of an FPD has been investigated. A total of 20 frameworks each were milled from presintered zirconia and from fully sintered zirconia. Prior to veneering, 10 frameworks of each material were 'damaged' by a defined saw cut similar to an accidental flaw generated during shape cutting. Before fracture testing, all FPDs were subjected to thermal and mechanical cycling. Additionally, scanning electron microscopy was used to investigate fracture surfaces. Statistical analysis showed that FPDs milled from fully sintered zirconia had a significantly higher fracture resistance compared with specimens made from presintered material, whereas preliminary damage did not have a significant effect. After aging, FPDs made from both materials were capable of withstanding occlusal forces reported in the literature. Therefore, both types of Y-TZP may be suitable for posterior four-unit all-ceramic FPDs, although further prolonged aging experiments and prospective clinical trials are required to prove their fitness for clinical use.

  11. Clinical fit of all-ceramic three-unit fixed partial dentures, generated with three different CAD/CAM systems.

    PubMed

    Reich, Sven; Wichmann, Manfred; Nkenke, Emeka; Proeschel, Peter

    2005-04-01

    In this study, the hypothesis was tested that the marginal and internal fit of CAD/CAM fabricated all-ceramic three-unit fixed partial dentures (FPDs) can be as good as in metal-ceramic FPDs. Twenty-four all-ceramic FPDs were fabricated and randomly subdivided into three equally sized groups. Eight frameworks were fabricated using the Digident CAD/CAM system (DIGI), another eight frameworks using the Cerec Inlab system (INLA). Vita Inceram Zirkonia blanks were used for both groups. In a third group frameworks were milled from yttrium-stabilized Zirconium blanks using the Lava system (LAVA). All frameworks were layered with ceramic veneering material. In addition, six three-unit metal-ceramic FPDs served as control group. All FPDs were evaluated using a replica technique with a light body silicone stabilized with a heavy body material. The replica samples were examined under microscope. The medians of marginal gaps were 75 microm for DIGI, 65 microm for LAVA and INLA and 54 microm for the conventional FPDs. Only the DIGI data differed significantly from those of the conventional FPDs. Within the limits of this study, the results suggest that the accuracy of CAD/CAM generated three-unit FPDs is satisfactory for clinical use.

  12. In Vitro Assessment of Single-Retainer Tooth-Colored Adhesively Fixed Partial Dentures for Posterior Teeth

    PubMed Central

    Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

    2010-01-01

    The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased. PMID:20652071

  13. Numerical modeling of the fracture process in a three-unit all-ceramic fixed partial denture.

    PubMed

    Kou, Wen; Kou, Shaoquan; Liu, Hongyuan; Sjögren, Göran

    2007-08-01

    The main objectives were to examine the fracture mechanism and process of a ceramic fixed partial denture (FPD) framework under simulated mechanical loading using a recently developed numerical modeling code, the R-T(2D) code, and also to evaluate the suitability of R-T(2D) code as a tool for this purpose. Using the recently developed R-T(2D) code the fracture mechanism and process of a 3U yttria-tetragonal zirconia polycrystal ceramic (Y-TZP) FPD framework was simulated under static loading. In addition, the fracture pattern obtained using the numerical simulation was compared with the fracture pattern obtained in a previous laboratory test. The result revealed that the framework fracture pattern obtained using the numerical simulation agreed with that observed in a previous laboratory test. Quasi-photoelastic stress fringe pattern and acoustic emission showed that the fracture mechanism was tensile failure and that the crack started at the lower boundary of the framework. The fracture process could be followed both in step-by-step and step-in-step. Based on the findings in the current study, the R-T(2D) code seems suitable for use as a complement to other tests and clinical observations in studying stress distribution, fracture mechanism and fracture processes in ceramic FPD frameworks.

  14. A comparative mechanical and bone remodelling study of all-ceramic posterior inlay and onlay fixed partial dentures.

    PubMed

    Field, Clarice; Li, Qing; Li, Wei; Thompson, Mark; Swain, Michael

    2012-01-01

    Comparative studies of bone remodelling and mechanical stresses between inlay and onlay fixed partial dentures (FPD) are rather limited. The purpose of this paper was to evaluate the biological consequence in posterior mandibular bone and the mechanical responses in these two different prosthetic configurations. Three-dimensional (3D) finite element analysis (FEA) models are created to explore the mechanical responses for the inlay and onlay preparations within the same oral environment. Strain induced bone remodelling was simulated under mastication. The remodelling adopted herein relates the strain in the bone to the change of Hounsfield Unit (HU) value in proportion to the surface area density (SAD) of bony morphology, which allows directly correlating to clinical computerised tomography (CT) data. The results show that both FPD designs exhibit a similar resultant change in bone mineral density (BMD) though the onlay configuration leads to a more uniform distribution of bone density. The inlay design results in higher mechanical stresses whilst allowing preservation of healthy tooth structure. This study provides an effective means to further clinical assessment and investigation into biomechanical responses and long-term restorative outcome with different FPD designs. Quantifying in vivo stress distributions associated with inlay/onlay FPDs can further supplement clinical investigations into prosthetic durability, FPD preparation techniques (i.e., taper angles, material development), consequent stress distributions and the ongoing biomechanical responses of mandibular bone. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. In vitro assessment of single-retainer tooth-colored adhesively fixed partial dentures for posterior teeth.

    PubMed

    Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

    2010-01-01

    The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased.

  16. A new design for all-ceramic inlay-retained fixed partial dentures: a report of 2 cases.

    PubMed

    Wolfart, Stefan; Kern, Matthias

    2006-01-01

    In a previous clinical study, all-ceramic resin-bonded 3-unit inlay-retained fixed partial dentures (IRFPDs) had a significantly worse outcome in the posterior region than did crown-retained 3-unit FPDs made from the same material. Debonding or fractures were causes of failure. To improve the clinical outcome of IRFPDs, a new framework design was developed: (1) The inlay retainers were made out of CAD/CAM-manufactured zirconia ceramic to improve fracture resistance, and additional veneering of the inlays was omitted. (2) The inlay retainers were completed with a shallow occlusal inlay (1-mm minimum thickness) and an oral retainer wing (0.6-mm minimum thickness). The wings were designed to reduce stress on the inlay retainer caused by torsion forces when the FPD is loaded nonaxially and to increase the enamel adhesive surface area. The pontic was circumferentially veneered with feldspathic porcelain. The clinical and laboratory procedures of this new treatment modality are described, and 2 exemplary clinical cases are presented. This new preparation and framework design might improve the clinical outcome of all-ceramic resin-bonded IRFPDs. However, adequate evidence of long-term safety and efficacy is required before this new design can be recommended for general clinical practice.

  17. Evolution of oral cancer treatment in an andalusian population sample: Rehabilitation with prosthetic obturation and removable partial prosthesis.

    PubMed

    Flores-Ruiz, Rafael; Castellanos-Cosano, Lizette; Serrera-Figallo, María-Angeles; Gutiérrez-Corrales, Aida; Gonzalez-Martin, Maribel; Gutiérrez-Pérez, Jose-Luis; Torres-Lagares, Daniel

    2017-08-01

    Radical surgical resection as a treatment modality for oral cancer often leads to an extensive deficit in both the maxillary and mandibular levels, where the use of a palatal obturator prosthesis (POP) or removable partial denture (RPP). The aim of this study was to evaluate the treatment with POP and RPP in patients treated for oral cancer in the Unit of Prosthetic Rehabilitation of the University Hospital Virgen del Rocío in a period of 20 years. Retrospective descriptive study during the years 1991 and 2011 analyzing oral cancer type, characteristics, treatment and follow-up. The sample consisted of patients whose tumor had previously been removed and who had been referred to the Oncological Rehabilitation Unit of the Oral and Maxillofacial Surgery Unit of the "Virgen del Rocío" University Hospital for rehabilitation. The inclusion criteria were patients whose underlying pathology was any type of neoplasia, which after its treatment had been referred to the aforementioned Oncological Prosthetic Rehabilitation unit. Of the 45 patients included in our study, 15 patients were rehabilitated with palatal obturator (33.3%) and 5 patients with removable partial denture (11.1%). The mean age of the sample of patients with POP was 57.3 ± 9.23, while the mean age of the sample of patients with RPP was 58 ± 13.5. The most common underlying pathology in patients with POP was squamous cell carcinoma (60%), whereas in patients with RPP it was 100%. The most frequent location found among POP patients was the upper jaw, while in the PRP patients there was no predominant location. The univariate and multivariate logistic regressions did not show any statistically significant association between the independent variables age, sex, smoking habit and alcoholic habit with the dependent variable type of rehabilitating prosthesis. Based on our data, we can conclude that RPP is used in few cases of oncological rehabilitation. The POP has a greater use, as long as the defect in the

  18. Epidemiology and etiology of denture stomatitis.

    PubMed

    Gendreau, Linda; Loewy, Zvi G

    2011-06-01

    Denture stomatitis, a common disorder affecting denture wearers, is characterized as inflammation and erythema of the oral mucosal areas covered by the denture. Despite its commonality, the etiology of denture stomatitis is not completely understood. A search of the literature was conducted in the PubMed electronic database (through November 2009) to identify relevant articles for inclusion in a review updating information on the epidemiology and etiology of denture stomatitis and the potential role of denture materials in this disorder. Epidemiological studies report prevalence of denture stomatitis among denture wearers to range from 15% to over 70%. Studies have been conducted among various population samples, and this appears to influence prevalence rates. In general, where reported, incidence of denture stomatitis is higher among elderly denture users and among women. Etiological factors include poor denture hygiene, continual and nighttime wearing of removable dentures, accumulation of denture plaque, and bacterial and yeast contamination of denture surface. In addition, poor-fitting dentures can increase mucosal trauma. All of these factors appear to increase the ability of Candida albicans to colonize both the denture and oral mucosal surfaces, where it acts as an opportunistic pathogen. Antifungal treatment can eradicate C. albicans contamination and relieve stomatitis symptoms, but unless dentures are decontaminated and their cleanliness maintained, stomatitis will recur when antifungal therapy is discontinued. New developments related to denture materials are focusing on means to reduce development of adherent biofilms. These may have value in reducing bacterial and yeast colonization, and could lead to reductions in denture stomatitis with appropriate denture hygiene.

  19. Masticatory performance and food acceptability in persons with removable partial dentures, full dentures and intact natural dentition.

    PubMed

    Wayler, A H; Muench, M E; Kapur, K K; Chauncey, H H

    1984-05-01

    This investigation indicated that measurable declines in masticatory function due to missing teeth, with and without prosthetic replacements, alter perceptual estimates of food acceptability. Using 1,133 male participants from the Veterans Administration Dental Longitudinal Study, individuals were classified into nine dentition categories to evaluate the effect of impaired masticatory ability. The data demonstrated that when limited declines in perceived masticatory function occur, perceptual estimates of Taste Acceptability, Texture Acceptability, and Ingestion Frequency for the 13 test foods utilized are not significantly modified. In contrast, when more severe dentition losses occur, the rheological properties of each food determine the degree to which these perceptual measures, especially Perceived Ease of Chewing, will be altered. Although restorative therapy can lead to concomitant improvements in masticatory function, low perceptual responses may still be observed. These appear to be largely a function of the physical attributes of the foods ingested.

  20. Different types of antagonists modify the outcome of complete denture renewal.

    PubMed

    Berteretche, Marie Violaine; Frot, Amélie; Woda, Alain; Pereira, Bruno; Hennequin, Martine

    2015-01-01

    The effect of renewing removable dentures on masticatory function was evaluated according to the occlusion offered by different types of mandibular arches. Twenty-eight patients with complete maxillary dentures were subdivided into three groups in terms of mandibular dentition type: dentate, partial denture, and complete denture. The participants were observed before and 8 weeks after maxillary denture renewal. The mandibular denture was also renewed in the partial and complete denture groups. The participants masticated carrots, peanuts, and three model foods of different hardnesses. The particle size distribution of the boluses obtained from natural foods was characterized by the median particle size (d50) in relation to the masticatory normative indicator (MNI). Chewing time (CT), number of chewing cycles (CC), and chewing frequency (CF) were video recorded. A self-assessment questionnaire for oral health-related quality of life (Geriatric Oral Health Assessment Index [GOHAI]) was used. Statistical analyses were carried out with a mixed model. Renewal of the dentures decreased d50 (P < .001). The number of participants with d50 values above the MNI cutoff decreased from 12 to 2 after renewal. Renewal induced an increase in mean CF while chewing model foods (P < .001). With all foods, renewal tended to affect CT, CC, and CF differently among the three groups (statistically significant renewal Å~ group interactions). The GOHAI score increased significantly for all groups. Denture renewal improves masticatory function. The complete denture group benefited least from renewal; the dentate group benefited most. This study confirmed the usefulness of denture renewal for improving functions and oral health- related quality of life.

  1. Clinical performance of a light-cured denture base material compared to polymethylmethacrylate--a randomized clinical study.

    PubMed

    Gohlke-Wehrße, Hanna-Lena; Giese-Kraft, Katja; Wöstmann, Bernd

    2012-06-01

    The aim of this study was to evaluate the clinical long-term performance of a visible light-cured resin (VLCR) denture base material and to compare it to a well-established polymethylmethacrylate (PMMA)-based denture acrylic in a randomized split-mouth clinical long-term study. One hundred removable partial dentures in 90 patients, with at least two saddles each, were investigated. One saddle was made of VLCR, while the other was made of PMMA at random. Plaque adhesion, tissue reaction, and technical parameters of the dentures were assessed 6, 12, and 18 months after treatment. Statistical analysis was performed using the Wilcoxon rank-sum test. Though VLCR showed higher plaque adhesion than PMMA after 6, 12, and 18 months (p < 0.001), there were no important differences with regard to tissue reaction. Concerning plaque adhesion, surface quality with regard to the lower side, interfaces between denture acrylic and metal and the boundary between denture acrylic and denture tooth PMMA was rated higher than VLCR. The surface quality of the upper side of the denture saddles showed no significant differences (p > 0.05). Neither VLCR nor PMMA showed discoloration at any point in time (p > 0.05). It can be concluded that VLCR is a viable alternative for the production of removable dentures. Especially in patients with hypersensitivities to PMMA, VLCR is particularly suitable for clinical use.

  2. Influence of resilient support of abutment teeth on fracture resistance of all-ceramic fixed partial dentures: an in vitro study.

    PubMed

    Rosentritt, Martin; Behr, Michael; Scharnagl, Peter; Handel, Gerhard; Kolbeck, Carola

    2011-01-01

    The influence of resilient support of abutment teeth on the fracture resistance of all-ceramic three-unit fixed partial dentures (FPDs) was tested in this study. Three groups (n = 8) of glass-infiltrated, alumina-based, all-ceramic FPDs that were adhesively bonded to human molar teeth were investigated. In control group A, teeth that were rigidly inserted in polymethyl methacrylate (PMMA) resin were used for thermocycling and mechanical loading (TCML), as well as for fracture testing. In group B, TCML was conducted on teeth that had their roots covered with a polyether layer. After TCML, the polyether layer was removed entirely, and the teeth were rigidly fixed in PMMA for fracture testing. In group C, teeth roots remained covered with a polyether layer during TCML as well as during fracture testing. Using a resilient attachment, tooth mobility was determined in axial, buccal, and oral directions. Mean tooth mobility was 76 ± 4 Μm in the axial direction, 278 ± 41 Μm in the buccal direction, and 128 ± 17 Μm in the oral direction. Group C showed the lowest mean fracture strength (polyether during both TCML and fracture testing) of 523 N. For group B (polyether during TCML but not during fracture testing), a fracture strength of 676 N was found, and for control group A (rigidly embedded teeth), it was 919 N. These results confirmed the influence of resilient attachments on the aging process and fracture strength testing of FPDs. Fracture resistance was significantly reduced when this particular interface was used in both TCML and fracture testing.

  3. Conservative and esthetic cast gold fixed partial dentures-inlay, onlay, and partial veneer retainers, custom composite pontics, and stress-breakers: part I: fundamental design principles.

    PubMed

    Stevenson, Richard G; Refela, Jane A

    2009-01-01

    Although in today's dental world implant restorations are considered the standard of care in the replacement of missing teeth, clinical contraindications and patient nonacceptance of implant placement can be encountered. Several scenarios are discussed here in which a single missing tooth can be restored with conservative fixed partial dentures (FPD) that employ cast gold retainers; each with a customized design in order to preserve tooth structure, maintain esthetics, and provide a long-term prognosis. The abutment teeth are prepared for conservative partial coverage restorations by using Brasseler burs (Brasseler USA, Savannah, GA, USA). Impressions are taken of the preparations, along with any retentive features, utilizing either the Vented Pin Channel technique or the Shooshan Plastic Pin technique. The latter technique utilizes Kodex twist drills and corresponding impression pins (Coltene Whaledent Inc., Mahwah, NJ, USA). The conservative FPD with non-rigid connectors is fabricated by using type III gold alloy. The pontic cage portion is chemically prepared utilizing the Panavia F2.0 cement kit (Kuraray America Inc., Houston, TX, USA) or other dual-polymerizing resin cement and restored with any type of direct composite resin material. A palette of opaquers and tints are used for chairside characterization of the esthetic pontic facing. The final polish of the pontic is completed by using FlexiDisc and FlexiBuff discs (Cosmedent Inc., Chicago, IL, USA). CLINICAL SIGNIFICANCE In cases where an implant restoration is contraindicated for replacement of a single tooth, a semi-precision FPD is a conservative, functional, and esthetic alternative.

  4. Effectiveness of denture cleanser associated with microwave disinfection and brushing of complete dentures: in vivo study.

    PubMed

    Sesma, Newton; Rocha, Alessandra Lima; Laganá, Dalva Cruz; Costa, Bruno; Morimoto, Susana

    2013-01-01

    Complete dentures acts as a reservoir for microbial colonization, which may lead to systemic infections. Microwave irradiation has been used as an efficient method of denture disinfection. Even though current methods eliminate denture-base microorganisms, a recurrence rate of denture stomatitis (DS) is still observed among denture-wearing patients. It was hypothesized that microwave disinfection kills microorganisms but do not remove dead bacteria from the denture surface. To test this hypothesis, the biofilm found in the dentures of 10 patients with DS was evaluated. In addition, the effects of microwave irradiation plus brushing (MW+B) on the denture biofilm and the combination of denture cleanser with microwave irradiation and brushing (MW+DC+B) for the removal of denture-accumulating microorganisms were investigated. Microbiological data were analyzed statistically by nonparametric analysis (Friedman/Wilcoxon, α=0.05). MW+B and MW+DC+B were effective in reducing the rate of microorganisms (99.2% and 99.5% respectively), but without significant difference between them (p=0.553). However, it was observed that the complete removal of microorganisms from denture surface was only possible when all regimens were combined (MW+DC+B). Microwave irradiation in combination with soaking in denture cleanser and brushing effectively disinfected the dentures and removed denture biofilm.

  5. Influence of screw surface treatment on retention of implant-supported fixed partial dentures.

    PubMed

    Boaventura de Moura, Marcos; Rodrigues, Renata Borges; Pinto, Leandro Moreira; de Araújo, Cleudmar Amaral; Novais, Veridiana Resende; Simamoto Júnior, Paulo César

    2017-06-19

    The aim of this study was to assess the effect of DLC (Diamond-like carbon) coating on the removal torque of prefabricated implant screws after cyclic loading. Four groups with two crowns supported by two implants (n=5) were obtained according to splinted and non-splinted prosthesis, using titanium or DLC screw (STi, SC, NSTi and NSC). The prosthetic screws were tightened at 32Ncm, retightened, and the specimens were submitted to 106 mechanical cycles (4Hz/98N). After cyclic loading, loosening torque was evaluated and the final measurements were performed. Data were analyzed by two-way ANOVA and Tukey's test (α=0,005). There was statistically significance in the interaction screw X splinting (p = 0.003). For the group that used titanium screw, NSTi showed smaller removal torque when compared with STi. It was concluded that the use of the DLC coating screw in non-splinted prosthesis maintain the torque after cyclic loading.

  6. Root canal therapy, fixed partial dentures and implant-supported crowns, have similar short term survival rates.

    PubMed

    Balevi, Ben

    2008-01-01

    Searches using the Medline, Cochrane and Embase databases and 'citation mining' (identifying references from included studies) were carried out. In addition, experts' recommendations for data sources were followed, and the table of contents of every issue of the most recent 2 years of a given list of dental journals were reviewed, the latter representing half of the total number of original research articles in English from the past 5 years on implant-supported crown (ISC), fixed partial dentures (FPD) and root canal (RC) therapy. Publication language was limited to English and grey literature was excluded, namely proceedings of conferences not listed in Medline, Cochrane or Embase databases, meetings and lectures. Comparative or noncomparative, prospective or retrospective longitudinal data were selected that related to clinical, biological, psychological and economic outcomes, as well as beneficial or harmful effects, of saving teeth by root canal treatment and/or alternative treatments, including: extracting the tooth and leaving an edentulous space or replacing the missing tooth with a fixed-partial-denture or implant-supported tooth. Three pairs of investigators (each team dealing with one of the three main treatment options) independently searched, selected and extracted data for analysis. Tables of evidence were created from articles that met the validity criteria. Each selected paper was given a quality score, where the maximum possible was 17. Discussion and consensus were used to resolve disagreement. Interpretation of the outcome data and classification of data according to success or survival and the type of study were verified by two statisticians. Qualitative and quantitative methods were used to integrate the evidence. The data were analysed by deciding whether and what data to combine, and measuring the statistical heterogeneity of the data using Cochrane Q and I statistics. For the purpose of comparison, clinical outcomes were grouped into three

  7. Effect of connector width on stress distribution in all ceramic fixed partial dentures (a 3D finite element study).

    PubMed

    Mokhtarikhoee, Sepideh; Jannesari, Alireza; Behroozi, Hamid; Mokhtarikhoee, Saeedeh

    2008-01-01

    Connectors in fixed partial dentures (FPDs) are the weakest areas and responsible for failure in most cases. Optimizing the design of connectors will lead to higher strength and better performance of all-ceramic FPDs. The aim of this study was to use the finite element method in order to simulate the effect of connector width on stress distribution in all-ceramic FPDs. Three 3-dimensional finite element models for a 3-unit FPD made of IPS-Empress 2 representing a lower first molar were created and a static load of 500 N was applied axially at mid pontic area. By choosing three different widths, 3 mm, 4 mm, 5 mm for connectors, three models I,II, and III for complete assembly of teeth and connectors were created. Maximum stress occurred in the connector area in all models. Compared to model I, stress decreased 24% in model III; so the wider connector lead to lower stress values. Connectors are the most regular area for the fracture in all-ceramic FPDs because of high concentration of stress. Decreasing the width of connector raises the stress and increases the risk for fracture. Also, maximum stress in bridges is less than half of the strength of IPS-Empress2 and no failure is expected for all cases. This in vitro study of 3-unit all ceramicFPDs made with IPS-Empress2 shows that an increase in the width of connector reduces the stress concentration and improves the likelihood of long-term prognosis. Also, IPS-Empress2 can be used in posterior regions in many cases.

  8. Prospective observation of CAD/CAM titanium-ceramic-fixed partial dentures: 3-year follow-up.

    PubMed

    Boeckler, Arne F; Lee, Heeje; Psoch, Andrea; Setz, Juergen M

    2010-12-01

    There is lack of knowledge about the clinical performance of computer-aided design/computer-aided manufacturing (CAD/CAM) titanium-ceramic-fixed partial dentures (FPDs). The purpose of this study was to evaluate CAD/CAM titanium-ceramic FPDs after 3 years in function. Thirty-one FPDs were fabricated for 23 patients. The Ti frameworks were completely fabricated using CAD/CAM technology, and the low-fusing porcelain was veneered. After confirming there were no mechanical or biological complications, the FPDs were cemented using zinc phosphate cement. The patients were recalled at 12, 24, and 36 months after cementation to examine for the presence of any mechanical complications, such as fractures of the veneering porcelain or the supportive framework, or biological complications, including caries, gingivitis, or periodontitis. The periodontal condition was measured using probing depth (PD), bleeding on probing (BOP), and plaque index (PI). Success and survival rates were estimated using the Kaplan-Meier analysis. There were four cohesive and three adhesive porcelain fractures, but no framework fractured. The Kaplan-Meier cumulative success rate of the CAD/CAM titanium-ceramic crown with regard to mechanical complications was 76.4%, and the cumulative survival rate was 96.8% after 3 years of use. One patient developed caries, but the condition was not associated with marginal discrepancy. No other biological complications were reported. The periodontal parameters demonstrated a tendency that slightly increased up to 24 months and was maintained by 36 months. At the end of the follow-up, PD was 2.86 mm, percentile of surface with BOP was 23.5, and PI was 0.45. The CAD/CAM titanium-ceramic FPDs survived in the mouths of patients without major complications for 3 years, although the risk of porcelain fracture appeared to be relatively high. © 2010 by The American College of Prosthodontists.

  9. Are endodontically treated incisors reliable abutments for zirconia-based fixed partial dentures in the esthetic zone?

    PubMed

    Tunjan, René; Rosentritt, Martin; Sterzenbach, Guido; Happe, Arndt; Frankenberger, Roland; Seemann, Rainer; Naumann, Michael

    2012-04-01

    This ex vivo pilot study tested the influence of defect extension and quartz-fiber post placement (QFP) on the ex vivo survival rate and fracture resistance of root-treated upper central incisors served as abutments for zirconia 2-unit cantilever fixed partial dentures (2U-FPDs) exposed to 10 years of simulated clinical function. Human maxillary central incisors were endodontically treated and divided into the following 5 groups (n = 8): (1) access cavity filled with core build-up composite, (2) biproximal class III cavities filled as in group 1, (3) specimens restored as in group 2 with QFP placed, (4) specimens decoronated and core buildup as in group 1, and (5) specimens restored as in group 4 but with QFP as in group 3. On all specimens, 2U-FPDs were placed with dual-curing resin cement. In order to simulate 10 years of clinical function, specimens were exposed to thermal cycling and mechanical loading with subsequent loading to failure. Kaplan-Meier curves were constructed, and log-rank tests were performed. Fracture force and patterns were compared by means of Kruskal-Wallis, Mann-Whitney U (post hoc), and Fisher exact tests, respectively (P = .05). For specimens only with an access cavity, it was observed that 25% had catastrophic tooth fractures and the lowest load-to-fracture values. In all other groups, chipping combined with or without debonding occurred. Groups did not differ significantly regarding the survival rate (P = .603) and fracture patterns (P = .633), but they did for fracture load including technical failures (P = .017). After 10 years of simulated clinical function, both defect extension and placement of QFP had no significant influence on survival of root-treated upper central incisors as abutments restored with zirconia-based 2U-FPDs. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Fracture toughness of cross-linked and non-cross-linked temporary crown and fixed partial denture materials.

    PubMed

    Balkenhol, Markus; Köhler, Heiko; Orbach, Katharina; Wöstmann, Bernd

    2009-07-01

    Temporary crowns and fixed partial dentures are exposed to considerable functional loading, which places severe demands on the biomaterials used for their fabrication (= temporary crown & bridge materials, t-c&b). As the longevity of biopolymers is influenced by the ability to withstand a crack propagation, the aim of this study was to investigate the fracture toughness of cross-linked and non-cross-linked t-c&bs. Four different t-c&bs (Luxatemp AM Plus, Protemp 3 Garant, Structur Premium, Trim) were used to fabricate bar shaped specimens (2mmx5mmx25mm, ISO 13586). A notch (depth 2.47mm) was placed in the center of the specimen using a diamond cutting disc and a sharp pre-crack was added using a razor blade. 60 specimens per material were subjected to different storage conditions (dry and water 37 degrees C: 30min, 60min, 4h, 24h, 168h; thermocycling 5-55 degrees C: 168h) prior to fracture (3-point bending setup). The fracture sites were inspected using SEM analysis. Data was subjected to parametric statistics (p=0.05). The K(IC) values varied between 0.4 and 1.3MPam(0.5) depending on the material and storage time. Highest K(IC) were observed for Protemp 3 Garant. Fracture toughness was significantly affected by thermocycling for all dimethacrylates (p<0.05) except for Structur Premium. All dimethacrylates showed a linear-elastic fracture mechanism, whereas the monomethacrylate showed an elasto-plastic fracture mechanism. Dimethacrylates exhibit a low resistance against crack propagation immediately after curing. In contrast, monomethacrylates may compensate for crack propagation due to plastic deformation. However, K(IC) is compromised with increasing storage time.

  11. Four-year clinical performance of a lithia disilicate-based core ceramic for posterior fixed partial dentures.

    PubMed

    Esquivel-Upshaw, Josephine F; Young, Henry; Jones, Jack; Yang, Mark; Anusavice, Kenneth J

    2008-01-01

    The objective of this research was to test the hypothesis that 3-unit fixed partial dentures (FPDs) made from a moderately high-strength core ceramic will adequately resist fracture in posterior regions if fabricated with a minimal connector size of 4 mm. Thirty ceramic FPD core frameworks were prepared using a hot-pressing technique and a lithia disilicate-based core ceramic. The maximum occlusal force was measured for each patient prior to tooth preparation. Connector heights and widths were measured for each FPD. Patients were recalled annually after cementation for 4 years and evaluated using 11 clinical criteria. All FPDs were examined by 2 independent clinicians, and rankings for each criterion were made from 1 to 4 (4 = excellent; 1 = unacceptable). The fracture rate was approximately 3% per year, and the proportion of good overall ratings in the nonfractured FPDs was reduced by more than 6% per year, where a good overall rating was defined to be a rank of 3 or 4 in all 11 criteria. There was little evidence that the use of either resin-reinforced glass-ionomer cement (Protec CEM) or dual-cure resin cement (Variolink II) made any difference in terms of fracture rate or overall rating (P= .30, .63, .97, and .71 for the 4 years, respectively). From a fracture resistance perspective, 4 of the 30 ceramic FPDs fractured within the 4-year evaluation period, representing an 86.7% success rate. Another FPD was replaced because of a caries lesion on 1 abutment tooth away from the margin. One FPD fracture was associated with the subject having the greatest occlusal force (1,031 N). The other 2 fractures were associated with FPDs that exhibited connector heights of less than 3 mm. All criteria were ranked good to excellent during the 4-year period for the remaining FPDs. Fractured FPDs were associated with a connector height of less than 4 mm; thus, the hypothesis was accepted.

  12. Fracture Strength of Three-Unit Implant Supported Fixed Partial Dentures with Excessive Crown Height Fabricated from Different Materials

    PubMed Central

    Nazari, Vahideh; Ghodsi, Safoura; Alikhasi, Marzieh; Shamshiri, Ahmad Reza

    2016-01-01

    Objectives: Fracture strength is an important factor influencing the clinical long-term success of implant-supported prostheses especially in high stress situations like excessive crown height space (CHS). The purpose of this study was to compare the fracture strength of implant-supported fixed partial dentures (FPDs) with excessive crown height, fabricated from three different materials. Materials and Methods: Two implants with corresponding abutments were mounted in a metal model that simulated mandibular second premolar and second molar. Thirty 3-unit frameworks with supportive anatomical design were fabricated using zirconia, nickel-chromium alloy (Ni-Cr), and polyetheretherketone (PEEK) (n=10). After veneering, the CHS was equal to 15mm. Then; samples were axially loaded on the center of pontics until fracture in a universal testing machine at a crosshead speed of 0.5 mm/minute. The failure load data were analyzed by one-way ANOVA and Games-Howell tests at significance level of 0.05. Results: The mean failure loads for zirconia, Ni-Cr and PEEK restorations were 2086±362N, 5591±1200N and 1430±262N, respectively. There were significant differences in the mean failure loads of the three groups (P<0.001). The fracture modes in zirconia, metal ceramic and PEEK restorations were cohesive, mixed and adhesive type, respectively. Conclusions: According to the findings of this study, all implant supported three-unit FPDs fabricated of zirconia, metal ceramic and PEEK materials are capable to withstand bite force (even para-functions) in the molar region with excessive CHS. PMID:28243301

  13. A retrospective evaluation of zirconia-fixed partial dentures in general practices: an up to 13-year study.

    PubMed

    Håff, Anna; Löf, Hanna; Gunne, Johan; Sjögren, Göran

    2015-02-01

    To evaluate zirconia-based fixed partial dentures (FPDs) after more than 8 years in clinical service. Patients treated between 2000 and 2004 with zirconia FPDs were identified from the records of a manufacturer of FPD substructures. Of the 45 patients who met the inclusion criteria 30 attended the appointment and 33 FPDs were evaluated using modified California Dental Association (CDA) criteria. In addition, plaque and the bleeding index were registered. Patient satisfaction with the restorations was evaluated using a 10-point visual analog scale (VAS). All the FPDs were made using CAD/CAM and hot isostatic pressed yttria-tetragonal zirconia polycrystal (HIPed Y-TZP) ceramic (Denzir) and were placed within general practices. The mean observation period was 9.6±1.6 years (range 3.0-13.1 years). The CDA rating was 90% satisfactory for the surface. Corresponding figures for anatomic form, color and margin integrity were 94%, 100% and 94%, respectively. Regarding surface three (9.7%) FPDs exhibited veneer chipping and were rated 'not acceptable'. For margin integrity two (6.5%) were rated 'not acceptable' because of caries. For anatomic form two (6.1%) were rated 'not acceptable' due to two lost FPDs. No significant differences were seen between the FPDs and controls for plaque and bleeding. The Kaplan-Meier survival rate (still in clinical function) was 94%, the success rate (technical events accounted for) 91% and (biological events accounted for) 73%. Based on the VAS the mean value for patient satisfaction was 9.3±1.2. Ninety-four percent of the FPDs were still in clinical function. HIPed Y-TZP could serve as an alternative for FPD treatments similar to those in the current study. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Analysis of load distribution in tooth-implant supported fixed partial dentures by the use of resilient abutment.

    PubMed

    Glisić, Mirko; Stamenković, Dragoslav; Grbović, Aleksandar; Todorović, Aleksandar; Marković, Aleksa; Trifković, Branka

    2016-01-01

    Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces. The objective of this study was to analyze load distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany) abutment and conventional non-resilient abutment using finite element method. This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made. For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa). Measurements of stress and deformation in the bone tissue in the model with application of the resilientTSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa). Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.

  15. The effect of placement and quantity of glass fibers on the fracture resistance of interim fixed partial dentures.

    PubMed

    Nohrström, T J; Vallittu, P K; Yli-Urpo, A

    2000-01-01

    Polymers used in interim fixed partial dentures (FPD) have recently been reinforced with fibers. The aim of this study was to determine the influence of the position of the fiber reinforcement on the fracture resistance of interim FPDs. In addition, the influence of quantity of fibers and the length of span of the FPD on the fracture resistance was investigated. FPDs were fabricated from a resin mixture of polyethylmethacrylate powder and n-butylmethacrylate liquid. Five FPDs from each group were made, and the FPDs were stored in water for 30 days before testing. The FPDs in the control group were unreinforced, and in the other groups the FPDs were reinforced either with two or three unidirectional continuous glass-fiber reinforcements and one woven glass-fiber reinforcement. Different quantities of fibers were used and the fibers were placed in different locations in the FPD. The load was applied to the FPD by a steel ball placed in the cavity in the middle fossa of the pontic tooth. The load required to fracture the unreinforced FPDs varied from 372 to 1061 N. Mean fracture load of reinforced FPDs varied from 508 to 1297 N. One-way analysis of variance showed that the length of span and the quantity of fibers significantly affected the fracture load (P < 0.001, n = 5). By lengthening the span of the FPD, the reinforcing effect of glass fibers became more obvious. The results of this study suggest that the effectiveness of glass-fiber reinforcement is most evident in interim FPDs with long spans and that the positioning of reinforcement considerably influences the strength of the FPD.

  16. Clinical long-term results of VITA In-Ceram Classic crowns and fixed partial dentures: A systematic literature review.

    PubMed

    Wassermann, Avi; Kaiser, Michael; Strub, Jörg R

    2006-01-01

    VITA In-Ceram Classic is a system designed to fabricate all-ceramic crowns and fixed partial dentures (FPDs) with a glass-infiltrated aluminum oxide core material. This systematic literature review gives an overview of the clinical performance of the VITA In-Ceram Classic Alumina, Spinell, and Zirconia restorations. Based on a systematic literature review, an evidence-based selection and assessment of clinical studies of VITA In-Ceram Classic ceramics was carried out. A total of 299 publications were found, 21 of which met the inclusion criteria. Only a few meaningful studies of In-Ceram Alumina FPDs and In-Ceram Zirconia crowns and FPDs were found. The 5-year survival rate of In-Ceram Alumina crowns and In-Ceram Spinell crowns ranged from 91.7% to 100% and is similar to the survival rate of conventional metal-ceramic crowns. The 5-year survival rate of single-retainer In-Ceram Alumina resin-bonded FPDs (RBFPDs) was 92.3%, which is higher than that of 2-retainer RBFPDs. In-Ceram Classic Alumina can be recommended for anterior and posterior crowns as well as for anterior single-retainer RBFPDs. Further studies should be initiated to evaluate in detail the clinical performance of In-Ceram Classic Alumina FPDs. In-Ceram Classic Spinell can be recommended for anterior crowns, especially if highly esthetic results are requested. For In-Ceram Classic Zirconia crowns or FPDs no statement can be made presently because of insufficient data.

  17. Denture Care Practices and Perceived Denture Status among Complete Denture Wearers

    PubMed Central

    Kosuru, Krishnam Raju V.; Devi, Ganji; Grandhi, Vikram; Prasan, Kumar K.; Yasangi, Manoj K.; Dhanalakshmi, Mannem

    2017-01-01

    Aims and Objectives: Considerable importance to oral health care was lacking in India, and oral health neglect continues to exist, which is evident in the low utilization rates and poor oral health status. Conventional dentures are the most common alternative in restoration of lost teeth. Without proper denture care practices, there is an increased risk of developing a multitude of problems. The aim of this study is to assess the denture care practices among complete denture wearers in East Godavari district, Andhra Pradesh. Materials and Methods: A cross-sectional study was conducted in the department of Prosthodontics at the Konaseema Institute of Dental Sciences, Amalapuram, Andhra Pradesh. Patients with self-care ability and adequate overall health who were using either single or full complete dentures for more than 6 months from the time of the study were requested to participate in the study. A total of 375 study participants were given a self-administered questionnaire on denture care practices followed by clinical examination of the denture status. Statistical analysis was done using the Statistical Package for the Social Sciences software for windows, version 20.0 (Armonk, NY: IBM Corp). Results: The majority of participants reported cleansing their dentures once a day, with brush and water, and had the habit of removing the dentures at night. Almost 80% of the participants reported their denture status to be good/fair. Clinical examination revealed that slightly more than half of the participants had poor denture status. Conclusion: This study highlights the need for improvement in patient education and counseling with respect to the maintenance of dentures and upkeep of denture hygiene. It also emphasizes the need for educating patients on how to evaluate the status of their dentures. PMID:28316948

  18. Denture Care Practices and Perceived Denture Status among Complete Denture Wearers.

    PubMed

    Kosuru, Krishnam Raju V; Devi, Ganji; Grandhi, Vikram; Prasan, Kumar K; Yasangi, Manoj K; Dhanalakshmi, Mannem

    2017-01-01

    Considerable importance to oral health care was lacking in India, and oral health neglect continues to exist, which is evident in the low utilization rates and poor oral health status. Conventional dentures are the most common alternative in restoration of lost teeth. Without proper denture care practices, there is an increased risk of developing a multitude of problems. The aim of this study is to assess the denture care practices among complete denture wearers in East Godavari district, Andhra Pradesh. A cross-sectional study was conducted in the department of Prosthodontics at the Konaseema Institute of Dental Sciences, Amalapuram, Andhra Pradesh. Patients with self-care ability and adequate overall health who were using either single or full complete dentures for more than 6 months from the time of the study were requested to participate in the study. A total of 375 study participants were given a self-administered questionnaire on denture care practices followed by clinical examination of the denture status. Statistical analysis was done using the Statistical Package for the Social Sciences software for windows, version 20.0 (Armonk, NY: IBM Corp). The majority of participants reported cleansing their dentures once a day, with brush and water, and had the habit of removing the dentures at night. Almost 80% of the participants reported their denture status to be good/fair. Clinical examination revealed that slightly more than half of the participants had poor denture status. This study highlights the need for improvement in patient education and counseling with respect to the maintenance of dentures and upkeep of denture hygiene. It also emphasizes the need for educating patients on how to evaluate the status of their dentures.

  19. Case report: a tale of two dentures.

    PubMed

    Beckett, H; Sequeira, P

    1998-12-01

    A case is presented where loss of an incisor tooth in a partial denture wearer created an aesthetic emergency. It was not possible to solve this simply by addition of a tooth to the existing denture. Reference to the previous dental history suggested that a further immediate solution might be unwise. The design of the existing denture lent itself to the novel solution of a second denture, retained by elements of the first.

  20. Rehabilitation of lost vertical dimension with cast post core and cast partial denture

    PubMed Central

    Gupta, Kavita; Javiya, Piyush; Kumar, Prachur; Mallikarjuna, Rachappa

    2013-01-01

    Loss of teeth is sometimes inevitable. But, it is the duty of a restorative dentist to restore the loss of teeth in way keeping in mind the discomfort and agony of the patient. Rehabilitation of these types of patients requires thorough knowledge and great skills on the part of a prosthodontist. This clinical case report describes the management of a 58-year-old male patient with a loss of mandibular posterior teeth and severely attrited anterior teeth opposing natural teeth. The treatment plan was to restore the loss of teeth and the loss of vertical dimension by providing prosthesis keeping in mind the occlusion and stomatognathic system. A novel approach of fixed and removable type of prostheses was implemented and successfully delivered. PMID:23813994

  1. Bone level change at implant-supported fixed partial dentures with and without cantilever extension after 5 years in function.

    PubMed

    Wennström, Jan; Zurdo, Jose; Karlsson, Stig; Ekestubbe, Annika; Gröndahl, Kerstin; Lindhe, Jan

    2004-12-01

    The aim of this study was to retrospectively analyze whether the inclusion of cantilever extensions increased the amount of marginal bone loss at free-standing, implant-supported, fixed partial dentures (FPDs) over a 5-year period of functional loading. The patient material comprised 45 periodontally treated, partially dentate patients with a total of 50 free-standing FPDs supported by implants of the Astra Tech System. Following FPD placement (baseline) the patients were enrolled in an individually designed supportive care program. A set of criteria was collected at baseline to characterize the FPDs. The primary outcome variable was change in peri-implant bone level from the time of FPD placement to the 5-year follow-up examination. The comparison between FPDs with and without cantilevers was performed at three levels: FPD level, implant level, and surface level. Bivariate analysis was performed by the use of the Mann-Whitney U-test and stepwise regression analysis was utilized to evaluate the potential influence of confounding factors on the change in peri-implant bone level. The overall mean marginal bone loss for the implant-supported FPDs after 5 years in function was 0.4 mm (SD, 0.76). The bone level change at FPDs placed in the maxilla was significantly greater than that for FPDs in the mandible (0.6 versus 0.2 mm; p<0.05). No statistically significant differences were found with regard to peri-implant bone level change over the 5 years between FPDs with and without cantilevers at any of the levels of comparisons. The multivariate analysis revealed that the variables jaw of treatment and smoking had a significant influence on peri-implant bone level change on the FPD level, but not on the implant or surface levels. The model explained only 10% of the observed variance in the bone level change. The study failed to demonstrate that the presence of cantilever extensions in an FPD had an effect on peri-implant bone loss.

  2. Marginal adaptation of 1 fiber-reinforced composite and 2 all-ceramic inlay fixed partial denture systems.

    PubMed

    Monaco, Carlo; Krejci, Ivo; Bortolotto, Tissiana; Perakis, Nikolaos; Ferrari, Marco; Scotti, Roberto

    2006-01-01

    The aim of this in vitro study was to evaluate the marginal adaptation and retention of inlay fixed partial dentures (IFPDs) made with 1 fiber-reinforced composite and 2 different ceramic materials using quantitative scanning electron microscope analysis after thermal cycling and mechanical loading, which simulated approximately 5 years of oral service. Eighteen IFPDs made with fiber-reinforced composite (SR Adoro/Vectris), zirconium oxide-TZP (Cercon), and magnesia partially stabilized zirconia (DC-Leolux) covered with silica-based ceramics were tested in this study. The specimens were mechanically loaded in the vestibular cusp of the pontic element in a computer-controlled masticator with 1,200,000 half-sinusoid mechanical cycles of maximum 49 N each at a frequency of 1.7 Hz. A total of 3,000 thermocycles at 5 degrees C and 55 degrees C, 2 minutes each, were performed simultaneously. The marginal adaptation was analyzed at the interface of the luting composite and the abutment inlay/onlay (CI) and at the interface of the tooth and the luting composite (TC). The percentages of continuous margin at the CI interface were 94.6 +/- 3.1 and 88 +/- 6.7 for Adoro/Vectris, 92.9 +/- 5 and 85.7 +/- 6.1 for Cercon, and 96.2 +/- 2.1 and 82.2 +/- 9.8 for DC-Leolux, respectively, before and after loading. The percentages of continuous margin at the TC interface were 86.7 +/- 6.7 and 62.5 +/- 16.4 for Adoro/Vectris, 93.3 +/- 3.4 and 83.2 +/- 5.9 for Cercon, and 96.1 +/- 2.4 and 75.3 +/- 7 for DC-Leolux. Statistically significant differences were found after loading between the fiber-reinforced composite and the 2 ceramic systems at the TC interface. Within the limitations of this experimental study with regard to the sample size and contacting vectors, the results showed that flexibility of the framework may play an important role in the marginal adaptation of the IFPDs. More rigid materials may transfer less stress to the margins, thus promoting a more stable adhesion to the

  3. 3D Finite Element Study on: Bar Splinted Implants Supporting Partial Denture in the Reconstructed Mandible

    PubMed Central

    El-Anwar, Mohamed; Ghali, Rami; Aboelnagga, Mona

    2016-01-01

    AIM: This study aimed to estimate the stress patterns induced by the masticatory loads on a removable prosthesis supported and retained by bar splinted implants placed in the reconstructed mandible with two different clip materials and without clip, in the fibula-jaw bone and prosthesis using finite element analysis. METHODS: Two 3D finite element models were constructed, that models components were modeled on commercial CAD/CAM software then assembled into finite element package. Vertical loads were applied simulating the masticatory forces unilaterally in the resected site and bilaterally in the central fossa of the lower first molar as 100N (tension and compression). Analysis was based on the assumption full osseointegration between different types of bones, and between implants and fibula while fixing the top surface of the TMJ in place. RESULTS: The metallic bar connecting the three implants is insensitive to the clips material. Its supporting implants showed typical behavior with maximum stress values at the neck region. Fibula and jaw bone showed stresses within physiologic, while clips material effect seems to be very small due to its relatively small size. CONCLUSION: Switching loading force direction from tensile to compression did-not change the stresses and deformations distribution, but reversed their sign from positive to negative. PMID:27275353

  4. Computer assisted mandibular reconstruction using a custom-made titan mesh tray and removable denture based on the top-down treatment technique.

    PubMed

    Ikawa, Tomoko; Shigeta, Yuko; Hirabayashi, Rio; Hirai, Shinya; Hirai, Kentaro; Harada, Naohiko; Kawamura, Noboru; Ogawa, Takumi

    2016-10-01

    The purpose of this report is to propose a computer assisted mandibular reconstruction procedure, utilizing a custom-made Ti-mesh tray with particulate cancellous bone and marrow, and a removable denture. This procedure was based on the top-down treatment technique, and reviews the case of a representative patient with mandibular continuity defect. The patient was a 74-year old female with a chief complaint of facial asymmetry and masticatory dysfunction. Due to gingival carcinoma, she underwent a segmental mandibulectomy on the left mandibule. On the VR space, using 3-D reconstructed computer tomography data, the residual right-side mandibular fragment was repositioned based on the condylar position and the occlusal relation. The mandibular fragment was then mirrored for a central sagittal plane. The position of the mirrored object was slightly arranged with the occlusal relation. Through the above operations, the landmark configuration, for the custom-made Ti-mesh tray as a virtual simulation model, was fabricated. On the physical model, we produced a custom-made Ti-mesh tray with a commercial Ti-mesh sheet. Surgical treatment was carried out using the tray. The denture pattern was designed by a dental technician on the VR space, fabricated using a 3D printer, and modified to create an impression tray with resin. Using the impression, the temporary removable denture was fabricated. We propose a computer assisted design for a custom-made Ti-mesh tray and a removable denture, based on the Top-down treatment concept. We feel this technique is advantageous in reconstructing functional occlusion, and in accurately regaining dental and facial esthetics. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  5. Survival and complication rates of implant-supported fixed partial dentures with cantilevers: a systematic review.

    PubMed

    Zurdo, José; Romão, Cristina; Wennström, Jan L

    2009-09-01

    The objective of the present systematic review was to analyze the potential effect of incorporation of cantilever extensions on the survival rate of implant-supported fixed partial dental prostheses (FPDPs) and the incidence of technical and biological complications, as reported in longitudinal studies with at least 5 years of follow-up. A MEDLINE search was conducted up to and including November 2008 for longitudinal studies with a mean follow-up period of at least 5 years. Two reviewers performed screening and data abstraction independently. Prosthesis-based data on survival/failure rate, technical complications (prosthesis-related problems, implant loss) and biological complications (marginal bone loss) were analyzed. The search provided 103 titles with abstract. Full-text analysis was performed of 12 articles, out of which three were finally included. Two of the studies had a prospective or retrospective case-control design, whereas the third was a prospective cohort study. The 5-year survival rate of cantilever FPDPs varied between 89.9% and 92.7% (weighted mean 91.9%), with implant fracture as the main cause for failures. The corresponding survival rate for FPDPs without cantilever extensions was 96.3-96.2% (weighted mean 95.8%). Technical complications related to the supra-constructions in the three included studies were reported to occur at a frequency of 13-26% (weighted mean 20.3%) for cantilever FPDPs compared with 0-12% (9.7%) for non-cantilever FPDPs. The most common complications were minor porcelain fractures and bridge-screw loosening. For cantilever FPDPs, the 5-year event-free survival rate varied between 66.7% and 79.2% (weighted mean 71.7%) and between 83.1% and 96.3% (weighted mean 85.9%) for non-cantilever FPDPs. No statistically significant differences were reported with regard to peri-implant bone-level change between the two prosthetic groups, either at the prosthesis or at the implant level. Data on implant-supported FPDPs with cantilever

  6. A Review on Denture Marking Systems: A Mark in Forensic Dentistry.

    PubMed

    Kareker, Nikita; Aras, Meena; Chitre, Vidya

    2014-12-01

    "Identification through forensic science is an art of giving the corpse a name A real life detective work that would put even Sherlock Homes to shame." Forensic dentistry deals with proper handling and examination of dental evidence and proper evaluation and presentation of dental findings in interest of justice. The Prosthodontists are playing a very important role in forensic dentistry as they are concerned with fabrication of various prosthesis which can serve as an important tool for identification. Identification is essential requirement of any medico-legal investigation because a wrong identity may pose a problem in delivering justice. This article describes the different methods for identification/marking of the complete dentures, removable partial dentures and fixed partial dentures and the importance of denture marking in forensic investigatory purposes. The PubMed, Ebsco and Google search engines were used to gather the articles.

  7. Palliative Care with Attachment Hybrid Removable Prosthesis

    PubMed Central

    2017-01-01

    Abutment injury, unsatisfactory aesthetics and lesser retention exist with the cast partial denture. Though these constraints exist in the Removable Partial Denture (RPD) it is still widely used because of the simplicity in design, fabrication, economics and patient comfort. This clinical report describes a hybrid RPD technique which uses extra coronal attachment that reduces the limitations and provides better comfort for the patient. PMID:28274077

  8. Oral health related quality-of-life outcomes of partially edentulous patients treated with implant-supported single crowns or fixed partial dentures

    PubMed Central

    2017-01-01

    Background Oral health-related quality of life (OHRQoL) is afflicted by different variables. Limited information is available regarding the impact of different phases of implant therapy on OHRQoL of edentulous patients. This study was carried out to assess the OHRQoL of patients treated with implant-supported single crowns or fixed partial dentures. Material and Methods A total of 79 healthy partially edentulous subjects needing implant therapy were incorporated in this study. Before placement of the implants, the subjects were instructed to fill the original version of OHIP questionnaire. Subsequently patients received titanium oral implants of the ITI® Dental Implant System. After 1st, 2nd and 3rd year of implant placement, patients filled the same OHIP-49 questionnaire. In this manner the impact of implant therapy on OHRQoL by putting in comparison pre- and post-treatment OHIP-49 scores was assessed. Statistical analyses were performed using Statistical Package for the Social Science software (SPSS, version 22, Chicago, IL, USA). Paired t test and Unpaired t test were performed and a statistical significance was set at 5% level of significance (p<0.05). Results Functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability were significantly decreased from baseline to 1st year (p<0.05) except handicap (p>0.05). All variables were also significantly decreased from baseline to 2nd year and 3rd year (p<0.05). There were no significant differences dependent on gender with respect to OHIP (p>0.05). Patients aged less than 60 years and more than 60 years of age groups differed significantly with respect to OHIP scores measured at 1st year, 2nd year and at 3rd year of implant placement (p<0.05). Conclusions Decrease in pre- and post-treatment OHIP scores OHIP demonstrated the significant increase in the OHRQoL after the therapy, which suggested increased levels of patient satisfaction. Key words

  9. The postoperative sensitivity of fixed partial dentures cemented with self-adhesive resin cements: a clinical study.

    PubMed

    Saad, Diaa El-Din; Atta, Osama; El-Mowafy, Omar

    2010-12-01

    The authors investigated the postcementation sensitivity associated with self-adhesive resin cements used with fixed partial dentures (FPDs). The authors recruited 20 patients who needed posterior porcelain-fused-to-metal FPDs and divided them randomly into three groups. They prepared 50 abutments, then cemented FPDs with one of two self-adhesive resin cements (Breeze Self-Adhesive Resin Cement, Pentron Clinical Technologies, Wallingford, Conn., and RelyX Unicem Self-Adhesive Universal Resin Cement, 3M ESPE, Seefeld, Germany) or an etch-and-rinse resin cement (RelyX ARC Adhesive Resin Cement, 3M ESPE, St. Paul, Minn.). The authors measured participants' tooth sensitivity to cold water, air blast and biting at 24 hours and at two, six and 12 weeks after FPD cementation by using a continuous visual analog scale (VAS). Data were analyzed statistically by means of the Mann-Whitney test. For cold tests, the highest VAS scores occurred 24 hours after cementation. The mean VAS scores associated with RelyX ARC were significantly higher than those associated with Breeze and RelyX Unicem (P < .001) at all test intervals. The mean cold-test VAS scores associated with Breeze and RelyX Unicem were not significantly different (P > .05). With all cements, sensitivity to cold decreased significantly after two to six weeks; however, with RelyX ARC, VAS scores stayed above the 30 percent level even after 12 weeks. The biting sensitivity associated with RelyX ARC was significantly higher than that associated with Breeze and RelyX Unicem (P < .001), and it remained above the 20 percent level even after 12 weeks. Those with Breeze-cemented FPDs had no sensitivity to biting, whereas those with RelyX Unicem-cemented FPDs had a mean biting sensitivity value of less than 5 percent at two weeks only. and Breeze and RelyX Unicem were associated with significantly lower postoperative tooth sensitivity values than was RelyX ARC. With Breeze and RelyX Unicem, postoperative tooth sensitivity

  10. Long-term evaluation of cantilevered versus fixed-fixed resin-bonded fixed partial dentures for missing maxillary incisors.

    PubMed

    Botelho, Michael G; Chan, Alex W K; Leung, Nic C H; Lam, Walter Y H

    2016-02-01

    To evaluate the long-term longevity and patient-reported outcomes of two-unit cantilevered (CL2) and three-unit fixed-fixed (FF3) resin-bonded fixed partial dentures (RBFPDs) for the replacement of a maxillary permanent incisor. Twenty-eight subjects were randomly assigned to receive either a CL2 or FF3 RBFPD placed by one operator. Prosthesis longevity was determined by clinical examination and history. Success was defined as absence of complications requiring intervention and survival as retention of the original prosthesis in mouth. Subjects' satisfaction was assessed using visual analogue scale (VAS) and oral health-related quality of life (OHRQoL) using Oral Health Impact Profile (OHIP-49). Outcomes were analysed with t-test/Mann-Whitney U test, chi-square and log-rank test at significance level α=0.05. Twenty-two subjects were reviewed. Thirteen of fifteen CL2 and ten of fourteen FF3 RBFPDs were examined (79.3 percent response rate) with a mean service life of 216.5±20.8months. All CL2 RBFPDs survived with no complications while only 10 percent of FF3 experienced no complications and only 50 percent of them survived (both P=0.000). CL2 had a significantly better success and survival rate than FF3 (P=0.000 and P=0.009, respectively). There was no significant difference in subjects' satisfaction and OHRQoL apart from CL2 group subjects had a higher satisfaction in cleaning of the prosthesis (84.1±13.6) than FF3 group (72.6±11.7) (P=0.05). Two-unit cantilevered RBFPDs were observed to have a significantly better success and survival than the FF3 design for the replacement of a maxillary incisor. Good patient-reported outcomes have been found for RBFPDs in single-tooth replacement in aesthetic zone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Marginal fit of alumina-and zirconia-based fixed partial dentures produced by a CAD/CAM system.

    PubMed

    Tinschert, J; Natt, G; Mautsch, W; Spiekermann, H; Anusavice, K J

    2001-01-01

    Clinical long-term success of all-ceramic dental restorations can be significantly influenced by marginal discrepancies. As a result, this in vitro study evaluated the marginal fit of alumina- and zirconia-based fixed partial dentures (FPDs) machined by the Precident DCS system. Different master steel models of three-, four- and five-unit posterior FPDs with an 0.8 mm chamfer preparation were produced. FPDs made of DC-Zirkon and In-Ceram Zirconia core ceramics were machined by the Precident DCS system. The marginal fit of the milled frameworks placed on the master steel models was determined by a replica technique using a light-body silicone to fill the discrepancies between crown and tooth and a heavy-body material to stabilize the light-body impression material. The impressions were poured into an epoxy resin material and each model was cross-sectioned with a low speed diamond saw to better visualize marginal discrepancies. The marginal fit of the FPDs was evaluated by scanning electron microscopy. The measurements of the marginal fit exhibited mean marginal discrepancies in a range between 60.5 and 74.0 microm, mean marginal gaps in a range from 42.9 to 46.3 microm, mean vertical discrepancies in a range from 20.9 to 48.0 microm and mean horizontal discrepancies in the range of 42.0 to 58.8 microm. Statistical data analysis was performed using the non-parametric test of Kruskal-Wallis and Mann-Whitney. The analysis revealed no significant differences (p>0.05) between the mean marginal gaps and vertical and horizontal discrepancies. However, for some FPDs the mean values of the marginal discrepancies were significantly different (p < or =0.05). The wide range of the measured values may be attributed to the complex geometrical design of long span FPDs and difficulties regarding the milling process of brittle ceramic materials. Based on the selection of 100 microm as the limit of clinical acceptability, the results of this study can conclude that the level of

  12. Repeated adjustment of new dentures for dysphagia.

    PubMed

    Hotta, Hiromi; Kanai, Yuki; Yamashita, Shuichiro

    2012-01-01

    When multiple tooth loss causes loss of occlusal-masticatory function, functional recovery is normally obtained with the help of removable dentures. After resection of the jawbone or tongue because of tumors, the movement of the tongue and its surrounding tissues is limited, and patients exhibit a more pronounced loss of chewing and swallowing than that observed in other cases of multiple tooth loss. In such cases, it is necessary to take extra care in determining the position of the mandible, arrangement of artificial teeth, and morphology of the palate. In the present case, the left lower jawbone was resected because of a gingival tumor, and when the new denture was manufactured, the intercuspal position was based on the resting position of the mandible. The stability of the lower complete denture was a priority and the artificial teeth were partially arranged on the lingual side. The new denture, however, caused insufficient closing of the mouth aperture and insufficient impact between tongue and palate, resulting in dysphagia. Therefore, the vertical dimension of occlusion was reduced multiple times to improve chewing and swallowing function.

  13. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures.

    PubMed

    Suedam, Valdey; Moretti Neto, Rafael Tobias; Sousa, Edson Antonio Capello; Rubo, José Henrique

    2016-04-01

    Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm) was used. Six groups were formed according to the alloy's framework (CoCr or PdAg) and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm). A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05) between the groups. Pearson correlation test (p<0.05) was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm.

  14. Swallowed dentures: Two cases and a review

    PubMed Central

    Gachabayov, Mahir; Isaev, Mubariz; Orujova, Lala; Isaev, Emin; Yaskin, Evgeniy; Neronov, Dmitriy

    2015-01-01

    Introduction Denture ingestion or aspiration is a problem requiring awareness of different specialists including dentists, surgeons, otolaryngologists, anesthesiologists etc. in terms of prevention, early diagnosis and adequate treatment. Complications of swallowed dentures include hollow viscus necrosis, perforation, penetration to neighbor organs leading to fistulae, bleeding and obstruction. Presentation of cases First case is a 54-year-old female who accidentally swallowed retractable one-tooth denture during fall about 22 h before admission and clinical manifestation of acute small bowel obstruction developed. The patient underwent laparotomy, enterotomy with retrieval of the foreign body. The second case is a 31-year-old male who accidentally ingested fixed one-tooth prosthesis while eating which impacted in the ileocaecal valve. During the preparation to colonoscopy the denture spontaneously passed out with stools. Discussion Denture ingestion is more common among patients with psychoneurologic deficit, alcohol and drug abusers. Among healthy and younger population denture ingestion is rare. Both reported patients are not elder. Thus dislodgement of removable or fixed dentures is another risk factor of denture ingestion. Most common site of denture impaction is esophagus; small bowel impaction is rare. Moreover, in most reported cases, small bowel impaction of ingested dentures leads to small bowel perforation. In our first case the complication of denture ingestion appeared to be bowel obstruction what is even rarer. Conclusion Fixed dentures can be accidentally ingested as well as removable dentures. Denture loosening leads to accidental denture ingestion. Patients with denture loosening should be recommended to visit dentist as soon as possible. PMID:26635957

  15. An audit to assess the quality and efficiency of complete and partial dentures delivered by junior hospital staff.

    PubMed

    Kalsi, Harpoonam J; Wang, Yon Jon; Bavisha, Kalpesh; Bartlett, David

    2010-03-01

    The average number of visits for the construction of metal-based and acrylic dentures by junior hospital staff was 10 visits. Our hypothesis was that supervision would optimise the number of visits and reduce any need for remakes. The first audit cycle was retrospective and included all patients treated by SHOs in the Prosthodontics Department. The standard of care was compared to the British Society for the Study of Prosthetic Dentistry. The re-audit showed that the time taken to completion was reduced by 2 visits for both denture types and the average length of time was reduced from 31 weeks to 22 weeks. These improvements were directly related to improved supervision by senior staff.

  16. Pattern waxes and inaccuracies in fixed and removable partial denture castings.

    PubMed

    Diwan, R; Talic, Y; Omar, N; Sadig, W

    1997-05-01

    It is the desire of every dentist and dental technician to produce a restoration that will fit the patient with a minimum of adjustments and certainly one that does not require remaking. Yet many abuse the materials with which they work, either through improper manipulation, lack of familiarity with their properties, or by attempting to reduce laboratory time by taking short cuts. Wax is one of the materials that requires more knowledge and skill to manipulate accurately because it has a considerably higher coefficient of thermal expansion (and contraction) than any other dental material. It often contributes considerably to the inaccuracies of cast dental restorations. This article provides a review of dental waxes used to make prosthodontic castings and points out some of the properties of waxes that must be controlled to make accurate restorations.

  17. Flexible Removable Partial Denture Prosthesis: A Survey of Dentists’ Attitudes and Knowledge in Greece and Croatia

    PubMed Central

    Lagouvardos, Panagiotis; Kranjcic, Josip; Vojvodic, Denis

    2015-01-01

    Purpose The aim of this study was to investigate through a questionnaire the knowledge, attitudes and possible differences in the use of flexible RPDPs among dentists in Greece and Croatia. Material and Methods A questionnaire of 16 questions was originally created in English, translated into Greek and Croatian language following a two way translation and tested for apprehension, precision, clarity and homogeneity by a number of native English speaking Greek and Croatian dentists. Following the necessary corrections, the questionnaires replicated in two online surveys and their addresses with an informed consent were sent by emails to nearly 4000 dentists in each country to participate. Collected data were analyzed by chi-square tests at a= .05 level of significance. Results 378 dentists from Greece and 304 from Croatia participated in the study. 137(36.2%) dentists from Greece and 56(18.4%) from Croatia provided flexible RPDPs to their patients. Statistical analysis for all providers indicated no significant difference between genders (P>.05), significant differences between age groups (P<.01), years of practice (P<.05), specialization (P <.001), and instruction on flexible prostheses (P <.001). The analysis between the two countries showed differences for gender and age groups (P<.01) but no differences between experienced, specialized or instructed groups (P >.05). Conclusion The survey indicated differences between the two countries in the percentages of dentists using, selecting and providing RPDPs for their patients. Practitioners’ age, years in practice and instruction were associated with the provision of the prostheses, while comfort, esthetics and cost were the reasons for deciding to use the flexible RPDPs. Conclusion Although dentists are not educated in their schools about flexible RPDPs, almost a third of them offer this treatment to their patients. Long term success of these devices depends on clinical education, more experience and definitely more research. PMID:27688416

  18. Sprue Design and Its Effect on the Castability and Porosity of Titanium Removable Partial Denture Frameworks

    DTIC Science & Technology

    1997-06-10

    creates a hazard to the laboratory technician, dentist and patient (ANSI/ADA Specification No. 41, 1982; Anusavice , 1985; Blanco-Dalmau, 1982; Com. Med...1982. American National Standards Institute, New York, NY: 414 Anusavice KJ. 1985. Report of base metal alloys for crown and bridge application

  19. The effect of carbon on the metallography of a nickel base removable partial denture casting alloy.

    PubMed

    Lewis, A J

    1979-04-01

    This study has demonstrated the pattern of carbide development associated with progressive increases in carbon content in a series of six nickel chromium alloys. The carbon content is critical since it influences the production and distribution of carbides, which have been shown to alter the mechanical properties, of the nickel chromium alloys, that are dependent upon the development of gamma prime. Furthermore, it has been shown that the attainment of suitable strength is invariably associated with an unacceptable level of ductility.

  20. The effect of aluminium on the metallography of a nickel base removable partial denture casting alloy.

    PubMed

    Lewis, A J

    1978-12-01

    Three special nickel-chromium alloys were prepared in which the aluminum levels were adjusted both above and below that of a commercial nickel base dental casting alloy. Tensile and metallographic evaluation of representative samples of the alloys were made and the changes in the properties of the alloys are reported.

  1. Interference factors regarding the path of insertion of rotational-path removable partial dentures.

    PubMed

    Huang, Chan-Te; Liu, Fang-Chun; Luk, Kwing-Chi

    2017-02-01

    The aims of this study were to evaluate the effect of the location of the rotational center and the morphology of teeth resulting in interference with the rotational path of insertion and to estimate when an interference test should be performed. A total of 400 dental radiograms of maxillary and mandibular first and second molars (100 for each position) were selected. The radiograms were used to hand-sketch the outlines on tracing paper. Then, an interference test was simulated using calipers. Mesial long occlusal rest seats with three different lengths were designed. A curve-simulated rotational path was drawn on the tracing paper showing the outline of a molar. If the curve was intersected by the mesial outline, interference was occurred. A total of 1200 tests were performed. A significant number of interference cases (18.5%, N = 400) occurred when the rotational center was placed at the most distal margin of the occlusal surface. The interference was reduced (2.75%, N = 400) but still present at the distal fourth of the occlusal surface. At the distal one-third of the occlusal surface, interference did not occur (0%, N = 400). There was a significant difference between the results of the three rotational centers (p < 0.0001). The interference test was not required for a rotational center at the distal third to half of the occlusal surface. However, if the length of the long occlusal rest extends beyond the distal third, an interference test is recommended before final impression. Copyright © 2017 Chang Gung University. Published by Elsevier B.V. All rights reserved.

  2. Control factors in removable complete dentures: from the articulation quintet to kinetic contact

    PubMed Central

    Pompa, Giorgio; Giovannetti, Agostino; Gentile, Tina; Di Carlo, Stefano

    2010-01-01

    Summary Hanau’s laws and the so-called articulation quintet have contributed greatly to the evolution of the prosthetic dentistry and have been further elaborated by various authors. The main aim of this study was to establish the stability of prosthetic plates by attaining balanced occlusion. Several authors have addressed the problem of removable and fixed prostheses by classifying mandibular movements into functional and parafunctional movements which extends the classical occlusal mechanics for the modern occlusal feedback model. Moreover, they suggest the use of the angle of convergence as a reference plane when manufacturing prosthetic. PMID:22238706

  3. Isolation of epithelial cells from acrylic removable dentures and gender identification by amplification of SRY gene using real time PCR.

    PubMed

    George, Renjith; Sriram, G; Saraswathi, Tr; Sivapathasundharam, B

    2010-01-01

    This study evaluates the usefulness of acrylic dentures as the source of DNA for forensic analysis. Thirty-eight samples (21 males and 17 females) were collected and stored for different time periods. The epithelial cells adhered to the dentures were retrieved and the genomic DNA was extracted. All the samples yielded sufficient amount of DNA for analysis irrespective of the storage time. Gender determination was done by amplification of the sex determining region on the Y chromosome (SRY) using real-time polymerase chain reaction with 100% accuracy, within minimal time. With this study, we conclude that saliva-stained acrylic dentures can act as a source of forensic DNA and co-amplification of SRY gene with other routine sex typing markers will give unambiguous gender identification.

  4. Survival rates of resin-bonded, glass fiber-reinforced composite fixed partial dentures with a mean follow-up of 42 months: a pilot study.

    PubMed

    Vallittu, Pekka K

    2004-03-01

    Although short-term clinical data exist for resin-bonded, glass fiber-reinforced composite fixed partial dentures (FPDs), long-term data are needed. The survival rates of 29 resin-bonded, glass fiber-reinforced composite fixed partial dentures were evaluated in this clinical study for periods of up to 42 months. FPDs were fabricated to replace 1 to 3 missing maxillary or mandibular teeth of 29 patients not able to be treated with conventional FPDs. Originally, there were 37 patients (the drop-out rate was 22%). The FPDs were retained with wings, inlays, complete coverage crowns, or combinations of these that were bonded to tooth structure. The FPD frameworks were made of continuous unidirectional E-glass fibers with a multiphase polymer matrix and light-polymerized particulate composite veneer. The patients were recalled for examinations, where a general dental examination was performed, 1 to 3 times per year for up to 63 months (minimum 24 months, mean 42 months). Partial or complete total debonding of the FPD or the framework fracture was considered a treatment failure. The data were analyzed with the Kaplan-Meier survival test (alpha=.05). Two resin frameworks fractured, and 3 frameworks were debonded. Kaplan-Meier survival probability at 63 months was 75%. Three of the failed FPDs were rebonded or repaired in situ, producing a functional survival rate of 93% after rebonding or repairing (mean survival time was 55 months). The results of this clinical study of 29 prostheses suggest that glass fiber-reinforced FPDs may be a possible alternative to cast metal resin-bonded FPDs. These restorations were successfully used as multiple-unit prostheses that employed a variety of abutment tooth preparation designs.

  5. Impact of prosthetic material on mid- and long-term outcome of dental implants supporting single crowns and fixed partial dentures: A systematic review and meta-analysis.

    PubMed

    Abou-Ayash, Samir; Strasding, Malin; Rücker, Gerta; Att, Wael

    2017-01-01

    The impact of prosthetic material selection on implant survival is not clear. The current criteria for choosing a prosthetic material seem to be based on clinician preferences. This systematic review aims to evaluate the impact of restorative materials on the mid- and long-term survival of implants supporting single crowns and fixed partial dentures. Hand and MEDLINE searches were performed to identify relevant literature for single crowns (SC) and fixed partial dentures (FPD). Further inclusion criteria were a mean follow-up period of at least 3 years, the inclusion of at least 10 patients in a relevant study cohort, and a clear description of prosthesis type and prosthetic material. A total of 63 studies for the SC group and 11 studies for the FPD group were included. Full arch restorations were not included. The materials utilised in the SC group were metal-ceramic (precious and non-precious), lithium-disilicate, veneered zirconia, veneered alumina, and nanoceramics. The materials used in the FPD group were metal-ceramic (precious), veneered titanium, metal-resin (precious), and veneered zirconia. No significant impact on the prosthetic material relating to mid- or long-term implant survival was identified. Furthermore, there were no statistically significant differences between the survival rates of the dental prostheses made from different materials (SC and FPD group). Single crowns made of nanoceramics showed a higher risk for decementation relative to other materials (0.80, 95% CI [0.67; 0.89]; P < 0.0001), whereas metal-resin FPDs showed a higher risk for chipping (0.36, 95% CI [0.23; 0.52]; P = 0.0072). The current evidence suggests that prosthetic material selection has no influence on mid- and long-term survival of implants restored with single crowns and fixed partial dentures. Similarly, the prosthetic material seems to have no significant impact on prosthetic survival rates. Further research is required to provide more evidence regarding the impact of

  6. Impacted dentures in the oesophagus.

    PubMed

    Bandyopadhyay, S N; Das, S; Das, S K; Mandal, A

    2014-05-01

    This study presents the incidence of denture impaction in the oesophagus, and discusses the difficulties of managing such cases. A total of 262 patients with a history of foreign body ingestion (between 1999 and 2010) were reviewed; 46 of these patients had dentures impacted in the oesophagus. The cervical section of the oesophagus was the commonest site of impaction. Dysphagia and tracheal tenderness were the most consistent features when dentures became impacted in the upper oesophagus. In most cases, rigid oesophagoscopy enabled successful removal of the impacted denture. Locating an impacted denture hidden within the oesophageal mucosal folds sometimes proved difficult. In cases of impacted dentures in the oesophagus, a positive history helps in the diagnosis, but a high degree of clinical suspicion aids early detection. Conventional radiographs are important but may not always be of assistance. Early intervention reduces complications. Dentures that are poorly maintained and old are more likely to be swallowed accidentally. The inclusion of radiopaque filler within dentures would assist localisation following accidental swallowing.

  7. Fabrication of a maxillary posterior fixed partial denture with a type 4 gold alloy and a dual-polymerizing indirect composite.

    PubMed

    Matsumura, Hideo; Mori, Shuichi; Tanoue, Naomi

    2008-03-01

    The aim of the present study was to design and fabricate a maxillary posterior fixed partial denture (FPD) made of a type 4 gold alloy and an indirect composite. Unlike the conventional framework design of a resin veneered restoration, cut-back was extended approximately 1/4 to 1/3 width in the occlusal table of the buccal cusp. Multiple retentive beads 150-200 mum in diameter were placed on the metal surface to be veneered. The gold alloy was cast in a cristobalite mold using a centrifugal casting machine. The cut surface with the retentive beads was air-abraded with alumina, and a priming agent (Alloy Primer) that contained triazine dithione monomer (VTD) was applied. A tooth-colored veneer was then fabricated with a highly loaded light- and heat-cured composite material (Estenia). This design and procedure can be applied as a standardized laboratory technique for fabrication of maxillary posterior restorations and FPDs.

  8. CAD/CAM milled removable complete dentures: an in vitro evaluation of trueness.

    PubMed

    Srinivasan, Murali; Cantin, Yoann; Mehl, Albert; Gjengedal, Harald; Müller, Frauke; Schimmel, Martin

    2017-07-01

    This study aimed to compare the trueness of one type of CAD/CAM milled complete removable dental prostheses (CRDPs) with injection-molding and conventionally manufactured CRDPs. Thirty-three CRDPs were fabricated by three different manufacturing techniques (group CAD/CAM (AvaDent™): n = 11; group injection molding (Ivocap™): n = 11; group flask-pack-press: n = 11) using a single master reference model and incubated in artificial saliva for 21 days. The trueness of the entire intaglio surface along with five specific regions of interest (vestibular-flange, palate, tuberosities, alveolar crest, and post-dam areas) was compared. Non-parametric tests were used with a level of significance set at p < 0.05. At baseline, there was no difference in the trueness of the total intaglio surfaces between the groups. After incubation, only the conventional CRDPs showed a significant improvement in trueness of the entire intaglio surface (p = 0.0044), but improved trueness was confirmed for all three techniques in most individual regions of interest. The 80-20 % /2 median quantile of the CAD/CAM group demonstrated the highest variability of individual readings, probably due to the size of the milling instrument. However, for all three techniques, 80 % of all deviations of the complete intaglio surface after incubation in saliva were below 0.1 mm. In this in vitro study, the trueness of the intaglio surface of all three investigated techniques seems to remain within a clinically acceptable range. Additional research is warranted on material-related aspects, cost-effectiveness, clinical performance, patient-centered outcomes, as well as other CAD/CAM techniques for CRDP fabrication. The intaglio surface trueness is an essential aspect in the clinical performance of CRDPs.

  9. Rehabilitation with implant-retained removable dentures and its effects on perioral aesthetics: a prospective cohort study.

    PubMed

    Lupi, Saturnino Marco; Cislaghi, Matteo; Rizzo, Silvana; Rodriguez Y Baena, Ruggero

    2016-01-01

    The onset of perioral wrinkles often prompts patients to request treatment. This aesthetic deterioration linked to aging may be associated with tooth and alveolar bone loss in fully edentulous patients. To evaluate perioral wrinkles before and after maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients. In this prospective cohort, single-center, blinded study, patients requiring maxillary and mandibular rehabilitation with implant-retained dentures were enrolled. The patients were photographed in the same position before and after oral rehabilitation. Wrinkles were evaluated in the photographs by blinded observers using validated rating scales. The following parameters were analyzed: upper and lower radial lip lines, marionette lines, upper and lower lip fullness, nasolabial folds, corner of the mouth lines, and the labiomental crease. Statistical analysis was performed using the Wilcoxon signed ranks test for paired data, with P<0.05 considered significant. Upper and lower implant-retained dentures were applied in 31 patients (15 males; mean ± standard deviation age 62.13±8.69 years, range 47-77 years). The oral rehabilitation procedures significantly improved (P<0.05) the upper and lower radial lip lines, marionette lines, upper and lower lip fullness, the nasolabial folds, and the corner of the mouth lines. Maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients improves perioral aesthetics. Patients requiring oral rehabilitation and desiring perioral aesthetic improvement could benefit from treatment with this type of prosthesis.

  10. Rehabilitation with implant-retained removable dentures and its effects on perioral aesthetics: a prospective cohort study

    PubMed Central

    Lupi, Saturnino Marco; Cislaghi, Matteo; Rizzo, Silvana; Rodriguez y Baena, Ruggero

    2016-01-01

    Background The onset of perioral wrinkles often prompts patients to request treatment. This aesthetic deterioration linked to aging may be associated with tooth and alveolar bone loss in fully edentulous patients. Purpose To evaluate perioral wrinkles before and after maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients. Methods In this prospective cohort, single-center, blinded study, patients requiring maxillary and mandibular rehabilitation with implant-retained dentures were enrolled. The patients were photographed in the same position before and after oral rehabilitation. Wrinkles were evaluated in the photographs by blinded observers using validated rating scales. The following parameters were analyzed: upper and lower radial lip lines, marionette lines, upper and lower lip fullness, nasolabial folds, corner of the mouth lines, and the labiomental crease. Statistical analysis was performed using the Wilcoxon signed ranks test for paired data, with P<0.05 considered significant. Results Upper and lower implant-retained dentures were applied in 31 patients (15 males; mean ± standard deviation age 62.13±8.69 years, range 47–77 years). The oral rehabilitation procedures significantly improved (P<0.05) the upper and lower radial lip lines, marionette lines, upper and lower lip fullness, the nasolabial folds, and the corner of the mouth lines. Conclusion Maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients improves perioral aesthetics. Patients requiring oral rehabilitation and desiring perioral aesthetic improvement could benefit from treatment with this type of prosthesis. PMID:27757052

  11. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures

    PubMed Central

    SUEDAM, Valdey; MORETTI, Rafael Tobias; SOUSA, Edson Antonio Capello; RUBO, José Henrique

    2016-01-01

    ABSTRACT Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm) was used. Six groups were formed according to the alloy’s framework (CoCr or PdAg) and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm). A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05) between the groups. Pearson correlation test (p<0.05) was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm. PMID:27119758

  12. [The dynamics of changes in rheological properties of oral fluid in patients with different levels of oral hygiene, using removable dentures].

    PubMed

    Mikhaylenko, T N; Ernestyuk, A M; Rozhko, N M

    2014-12-01

    The issue of changing the physical and physico-chemical characteristics of oral fluid and their dependence on the level of oral hygiene in patients with removable dentures, requires further study. Therefore, in 86 individuals with 138 removable dentures, and 34 patients who are dentally and somatically healthy, we have had studied the parameters of viscosity, velocity of salivation, pH and concentration of mucin. According to the results of the factor analysis, it was determined that 78.6% of the studied parameters were indicators of hygienic condition of oral cavity. On the basis of significant difference and the strength and direction of correlation between the studied parameters and values of the integral index of oral hygiene, it was found, that in patients without somatic pathology with proper oral hygiene, we observed the growth of the rate of salivation and pH(c1), and in case of improper hygienic condition - reducing rate of salivation and increasing concentration of mucin. In case of the presence of somatic pathology, with an improvement of oral hygiene, the growth of pH(c1) and reducing of concentration of mucin was observed. The deterioration of oral hygiene level led to the increase of the rate of viscosity and the reduction of the salivation rate.

  13. All-ceramic fixed partial dentures. Studies on aluminum oxide- and zirconium dioxide-based ceramic systems.

    PubMed

    Vult von Steyern, Per

    2005-01-01

    The development of refined, tougher, and stronger ceramic core materials in recent years has led to the wider use of new, strong all-ceramic systems based on oxide ceramics. Results from in-vitro studies investigating the use of oxide ceramics in shorter all-ceramic fixed partial dentures (FPDs) have been positive, but clinical studies and additional in-vitro studies are needed to confirm the advisability of such procedures. One aim of this thesis was to investigate whether alumina-based and zirconia-based material systems are adequate for use in shorter (< or = five-unit) FPDs and to evaluate the clinical results. Additional aims were to investigate how to achieve optimal fracture strength in an all-ceramic FPD by varying the try-in procedure, the cervical shape of the abutments, and the support of the FPD (abutment teeth or dental implants). The final aim was to compare the strength of a zirconia material system with that of an alumina equivalent with known long-term clinical performance. Two clinical studies investigating one alumina-based and one zirconia-based material system were performed. Twenty posterior, three-unit FPDs (glass-infiltrated alumina) were followed for 5 years and 20 three-five-unit FPDs (HIP zirconia) for 2 years. Long-term follow-ups were made after 11 +/-1 (glass-infiltrated alumina) and 3 years (HIP zirconia). In three in-vitro studies, the following variables were investigated: (1a) the flexural strength of porcelain specimens depending on whether they were exposed to saliva before the glaze firing (n=20) or first after the glaze firing (n=20), (1b) the fracture strength of three-unit all-ceramic FPDs (glass-infiltrated alumina) supported by abutments prepared with cervical shoulder preparations (n=9) and abutments with cervical chamfer preparations (n=9), (2) the fracture strength of crowns (n=30) made of a zirconia material system (densely sintered zirconia) and of crowns (n=30) of an alumina material system (densely sintered alumina

  14. The Oral Microbiome of Denture Wearers Is Influenced by Levels of Natural Dentition

    PubMed Central

    O’Donnell, Lindsay E.; Robertson, Douglas; Nile, Christopher J.; Cross, Laura J.; Riggio, Marcello; Sherriff, Andrea; Bradshaw, David; Lambert, Margaret; Malcolm, Jennifer; Buijs, Mark J.; Zaura, Egija; Crielaard, Wim; Brandt, Bernd W.; Ramage, Gordon

    2015-01-01

    Objectives The composition of dental plaque has been well defined, whereas currently there is limited understanding of the composition of denture plaque and how it directly influences denture related stomatitis (DS). The aims of this study were to compare the microbiomes of denture wearers, and to understand the implications of these towards inter-kingdom and host-pathogen interactions within the oral cavity. Methods Swab samples were obtained from 123 participants wearing either a complete or partial denture; the bacterial composition of each sample was determined using bar-coded illumina MiSeq sequencing of the bacterial hypervariable V4 region of 16S rDNA. Sequencing data processing was undertaken using QIIME, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. The dentures were sonicated to remove the microbial flora residing on the prosthesis, sonicate was then cultured using diagnostic colorex Candida media. Samples of unstimulated saliva were obtained and antimicrobial peptides (AMP) levels were measured by ELISA. Results We have shown that dental and denture plaques are significantly distinct both in composition and diversity and that the oral microbiome composition of a denture wearer is variable and is influenced by the location within the mouth. Dentures and mucosa were predominantly made up of Bacilli and Actinobacteria. Moreover, the presence of natural teeth has a significant impact on the overall microbial composition, when compared to the fully edentulous. Furthermore, increasing levels of Candida spp. positively correlate with Lactobacillus spp. AMPs were quantified, though showed no specific correlations. Conclusions This is the first study to provide a detailed understanding of the oral microbiome of denture wearers and has provided evidence that DS development is more complex than simply a candidal infection. Both fungal and bacterial kingdoms clearly play a role in defining the progression of DS, though we were unable to

  15. [Application of valplast dentures in the temporary restoration of single missing anterior tooth].

    PubMed

    Zhou, Zheng; Hu, Yun-dong; Sui, Qing-song; Yan, Nian-jun; Ye, Ren

    2011-06-01

    To evaluate the value of valplast dentures in the temporary restoration of single missing anterior tooth. Totally 76 patients who needed temporary restoration of single missing anterior tooth were involved and equally divided into two groups according to their own choices of procedures: group A, with valplast dentures as their temporary dentures and group B, with conventional removable partial dentures as their temporary dentures. Meanwhile,38 patients who had their single anterior teeth pulled out and did not need temporary dentures were enrolled as control group without any temporary restoration, and impressions were taken immediately before the temporary dentures were used (2 weeks after tooth extraction) and before the initiation of permanent restorations (97-100 days after tooth extraction).The heights of clinical crowns of the adjacent teeth were also recorded twice from plaster models made from the impressions.The height of labial gingiva recession was calculated as the difference between the two heights recorded. The height differences of clinical crowns of the adjacent teeth was 0.5mm (range: 0.0-1.2mm) in group A, which was significantly larger than those in group B [0.0mm;(range: 0.0-0.6mm)](P<0.05) and in group C[0.0mm;(range: 0.0-0.4mm)](P<0.05).However, the difference was not significant between group B and group C (P>0.05). Application of valplast denture as temporary denture may cause labial gingival recession of the adjacent teeth, and therefore is not suitable for the restoration of single missing anterior tooth.

  16. Clinical evaluation of three denture cushion adhesives by complete denture wearers.

    PubMed

    Koronis, Spyros; Pizatos, Evangelos; Polyzois, Gregory; Lagouvardos, Panagiotis

    2012-06-01

    The aim of this study was the clinical evaluation of three denture cushion adhesives and whether the results were correlated to Kapur Index for denture-supporting tissues. Various types of denture adhesives are used among denture patients. However, information on the clinical behaviour of denture cushions is limited. Thirty edentulous patients had their denture-supporting tissues scored by Kapur Index and their old dentures replaced. They received three brands of denture cushion adhesives (Fittydent(®) , Protefix(®) and Seabond(®)) and were instructed to use them in a sequence according to the group they were randomly assigned to. Each brand of adhesive was used for 48 h on the lower denture according to the manufacturer's suggestions. After each brand was used, participants spent 24 h without applying any sort of adhesive. Finally, a questionnaire evaluating and comparing the performance of each brand was filled out. Denture adhesives generally improved patient satisfaction and masticatory ability, especially in participants with poor Kapur Index and those who reported a poor retention of their old dentures. Fittydent(®) was the most preferred adhesive, showing the best retention and the longest duration of its effect, but also reported as difficult to remove from the denture-bearing area. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

  17. Denture Adhesives

    MedlinePlus

    ... bone and give temporary relief from loosening dentures. Zinc and Potential Risk Zinc is a mineral that is an essential ingredient ... in some dietary supplements. However, an excess of zinc in the body can lead to health problems ...

  18. An effective technique for denture border evaluation.

    PubMed

    Phoenix, R D; DeFreest, C F

    1997-09-01

    Proper extension and adjustment of denture borders is a critical component in successful removable prosthodontic treatment. Unfortunately, commonly marketed disclosing media may not provide appropriate viscosities for the accurate assessment of denture border extensions. This article provides a technique for the mixing, unit-dose packaging, and utilization of a disclosing medium that is extremely well-suited for denture border applications. The technique employs commonly available materials and compiles with current "unit-dose" guidelines.

  19. Dentin microhardness of primary teeth undergoing partial carious removal.

    PubMed

    Dalpian, Débora Martini; Casagrande, Luciano; Franzon, Renata; Dutra, Giovana Martins Cezar; de Araujo, Fernando Borba

    2012-01-01

    To evaluate the dentin microhardness of primary teeth undergoing indirect pulp capping (IPC) after partial caries removal. Primary molars were treated with IPC, restored with self-etching primer (Clearfil SE Bond; CSE), and filled with composite resin (Filtek Z250) with (n = 10) or without (n = 7) a calcium hydroxide base liner (Dycal; Dy). After tooth exfoliation, the microhardness of the demineralized dentin remaining under the restoration (n = 17) was analyzed and compared with that of sound and carious primary dentin (n = 20). Microhardness measurements were obtained from the deepest portion of the cavity until the roof of the pulp chamber. Data were analyzed by Kruskal-Wallis test (p < 0.05). There was no difference in microhardness values at all depths between the treated groups (DY and CSE), but when the exfoliated carious teeth were included, the CSE had significantly higher values at 35-microm depth. This difference was only detected in the DY group after a depth of 200 microm. At 700 microm, there was no difference in microhardness values between all 4 groups. Primary teeth that underwent IPC showed the same microhardness, regardless of the capping material used.

  20. A 2-year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures.

    PubMed

    Karlsson, U; Gotfredsen, K; Olsson, C

    1998-08-01

    In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO-blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100% (TiO-blasted) vs 95.3% (machined), P = 0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 types of implant after 2 years of loading, 0.04 (0.82) mm, P > 0.30.

  1. Denture adhesive use in complete dentures: clinical recommendations and review of the literature.

    PubMed

    Duqum, Ibrahim; Powers, Kendall Ann; Cooper, Lyndon; Felton, David

    2012-01-01

    This literature review sought to determine the advantages and disadvantages of denture adhesive use among complete denture patients. Manuscripts were obtained by searching the National Library of Medicine's PubMed database, Cochrane Collaboration Library, ADA Center for Evidence-Based Dentistry website, and EMBASE database. A total of 85 abstracts were reviewed, and 38 articles that met the inclusion criteria for this review were selected. The inclusion criteria included clinical trials and case series in which 10 or more patients were treated, as well as Cochrane collaboration reviews and in vitro studies where clinical relevance could be determined. The selected manuscripts were reviewed using a standardized manuscript review matrix. Although denture adhesives improve the retention and function of complete dentures, standardized guidelines are needed for the proper use, application, and removal of denture adhesives. Additionally, long-term studies are warranted on the biologic effects of denture adhesives. There is a need to establish a regular recall program for complete denture patients.

  2. Partial Denture Alloy-Denture Cleanser Interaction,

    DTIC Science & Technology

    1980-07-24

    Lambert Co., Morris Plains, NJ 07950; and Mersene , Colgate Palmolive Co., New York, NY 10022. 11 4 Minute, Dent-Mat, Inc., Santa Maria, CA 03456...potentials was delineated by the interaction of Ticonium 100 with Mersene (-500 my vs SCE) and Durallium LG with Calgon-Clorox (0mvvs SCE). ## Universal...behavior of Ticonium 100 in Calgon-Clorox (Fig. 2), Mersene (Fig. 3), Polident (Fig. 4) and Efferdent (Fig. 5) was typified by decreased

  3. Survival rates of a lithium disilicate-based core ceramic for three-unit esthetic fixed partial dentures: a 10-year prospective study.

    PubMed

    Solá-Ruiz, M Fernanda; Lagos-Flores, Elena; Román-Rodriguez, Juan Luis; Highsmith, Jaime Del Rio; Fons-Font, Antonio; Granell-Ruiz, Maria

    2013-01-01

    The aim of this prospective study was to evaluate the clinical efficacy and long-term survival rate of three-unit fixed partial dentures (FPDs) made from lithium disilicate-based core ceramic. Twenty-one three-unit FPDs were placed in 19 patients to replace single lost teeth in the esthetic area, following a study protocol that took clinical, esthetic, and radiologic aspects into consideration. Each case was reviewed at 1 week following placement, at 6 months, and then annually for 10 years. Statistical analysis was performed using Kaplan-Meier survival analysis. Out of the 19 patients, 14.3% presented reversible postoperative sensitivity. Recession was observed in 24% of dental posts, and 7.1% presented marginal discoloration. Treatment did not increase either Bleeding or Plaque Index scores at prepared teeth; secondary caries did not appear either. The restorations' survival rate at the 10-year follow-up was 71.4%; six FPDs had fractured and one debonded. Fracture failure rate was 28.6% after 10 years; a high percentage corresponded to connector fractures and occurred during the first 5 years. Lithium disilicate glass-ceramic FPDs present a higher risk of fracture than standard therapies (metal-ceramic) or other more recently developed ceramic materials. The prognosis for survival improves for Class I occlusion and nonparafunctional patients.

  4. Impact of Denture Usage Patterns on Dietary Quality and Food Avoidance among Older Adults

    PubMed Central

    Savoca, Margaret R.; Arcury, Thomas A.; Leng, Xiaoyan; Chen, Haiying; Bell, Ronny A.; Anderson, Andrea M.; Kohrman, Teresa; Gilbert, Gregg H.; Quandt, Sara A.

    2011-01-01

    This study categorizes older adults living in rural areas by denture status, assesses the frequency of wearing dentures during meals, and determines whether denture status or use is associated with dietary quality or the number of foods avoided. A multi-ethnic population-based sample of adults ≥60 years (N=635) in the rural US was interviewed. Survey included denture use, removing dentures before eating, and foods avoided due to oral health problems. Dietary intakes were converted into Healthy Eating Index-2005 scores. Sixty percent wore removable dentures of some type; 55% never, 27% sometimes, and 18% always removed dentures when eating. More frequent removal was associated with lower dietary quality and more foods avoided. Those with severe tooth loss had the lowest dietary quality and avoided the most foods. Many rural older adults wear dentures. Learning how they adapt to denture use will offer insight into their nutritional self-management and help explain differences in dietary quality. PMID:23286643

  5. 2-Methacryloyloxyethyl Phosphorylcholine Polymer Treatment of Complete Dentures to Inhibit Denture Plaque Deposition.

    PubMed

    Ikeya, Kenji; Fukunishi, Miya; Iwasa, Fuminori; Inoue, Yuuki; Ishihara, Kazuhiko; Baba, Kazuyoshi

    2016-12-26

    Removable dentures made of poly (methyl methacrylate) (PMMA) are prone to bacterial adherence and dental plaque formation, which is called denture plaque. Denture plaque-associated infection is a source of serious dental and medical complications in the elderly. 2-Methacryloyloxyethyl phosphorylcholine (MPC) is a well-known biomedical material that exhibits marked antithrombogenicity and tissue compatibility because of its high resistance to protein adsorption and cell adhesion. Therefore, MPC polymer coatings are suggested to have the potential to inhibit plaque deposition on the surface of PMMA dentures. However, coating MPC polymer on the surface of a PMMA denture is a complex procedure that requires specialized equipment, which is regarded as a major barrier to its clinical application. Here, we introduce a new MPC polymer treatment procedure that uses poly (MPC-co-BMA-co-MPAz) (PMBPAz) to prevent denture plaque deposition on removable dentures. This procedure enables the MPC coating of PMMA denture surfaces in a simple and stable manner that is resistant to various chemical and mechanical stresses due to the MPC layer of PMBPAz that is covalently bound to the PMMA surface by ultraviolet light irradiation. In addition, the procedure does not require any specialized equipment and can be completed by clinicians within 2 min. We applied this procedure in a clinical setting and demonstrated its clinical utility and efficacy in inhibiting plaque deposition on removable dentures.

  6. Denture adhesives: a systematic review.

    PubMed

    Papadiochou, Sofia; Emmanouil, Ioannis; Papadiochos, Ioannis

    2015-05-01

    Denture adhesives have been the objective of scientific research for over half a century. Although they are used by denture wearers worldwide, investigations of their effectiveness and biocompatibility have led to controversial conclusions. The purpose of this study was to review the literature data with regard to the effectiveness and biocompatibility of denture adhesives as well as the attitudes of both patients and dental professionals toward these materials. An electronic search of English peer-reviewed dental literature in the Medline database was conducted to evaluate the effectiveness and biocompatibility of denture adhesives. There was no limitation in publication year, so the search included all the available scientific evidence included in that particular database until March 2014. Specific inclusion criteria were used for the selection of the appropriate articles. A manual search of the citations of the obtained articles followed to extend the electronic search. A full text review was carried out for only 32 articles. Of the 32 articles, 21 examined the efficacy of denture adhesives in terms of retention and stability and masticatory performance, 6 evaluated the issue of the biocompatibility of denture adhesives, and 5 presented the attitudes of either professionals or patients toward these materials. The majority of clinical studies supported the fact that denture adhesives enhance the retention, stability, and masticatory performance of a removable prosthesis. In terms of biocompatibility, long-term in vivo studies to investigate potential harmful effects were lacking. Patients are satisfied with denture adhesives that meet their needs. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. Utilization of Partially Gasified Coal for Mercury Removal

    SciTech Connect

    Chris Samuelson; Peter Maly; David Moyeda

    2008-09-09

    In this project, General Electric Energy and Environmental Research Corporation (EER) developed a novel mercury (Hg) control technology in which the sorbent for gas-phase Hg removal is produced from coal in a gasification process in-situ at a coal burning plant. The main objective of this project was to obtain technical information necessary for moving the technology from pilot-scale testing to a full-scale demonstration. A pilot-scale gasifier was used to generate sorbents from both bituminous and subbituminous coals. Once the conditions for optimizing sorbent surface area were identified, sorbents with the highest surface area were tested in a pilot-scale combustion tunnel for their effectiveness in removing Hg from coal-based flue gas. It was determined that the highest surface area sorbents generated from the gasifier process ({approx}600 m{sup 2}/g) had about 70%-85% of the reactivity of activated carbon at the same injection rate (lb/ACF), but were effective in removing 70% mercury at injection rates about 50% higher than that of commercially available activated carbon. In addition, mercury removal rates of up to 95% were demonstrated at higher sorbent injection rates. Overall, the results of the pilot-scale tests achieved the program goals, which were to achieve at least 70% Hg removal from baseline emissions levels at 25% or less of the cost of activated carbon injection.

  8. Bioretention Systems: Partial Factorial Designs for Nitrate Removal

    EPA Science Inventory

    Changes in nutrient loadings are monitored by introducing captured stormwater runoff into eight outdoor rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey scaled for residential and urban landscapes. The partial factorial design includes non-vegetated meso...

  9. Bioretention Systems: Partial Factorial Designs for Nitrate Removal

    EPA Science Inventory

    Changes in nutrient loadings are monitored by introducing captured stormwater runoff into eight outdoor rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey scaled for residential and urban landscapes. The partial factorial design includes non-vegetated meso...

  10. Ultrasound gel minimizes third body debris with partial hardware removal in joint arthroplasty.

    PubMed

    McGrory, Aidan C; Replogle, Lee; Endrizzi, Donald

    2017-03-01

    Hundreds of thousands of revision surgeries for hip, knee, and shoulder joint arthroplasties are now performed worldwide annually. Partial removal of hardware during some types of revision surgeries may create significant amounts of third body metal, polymer, or bone cement debris. Retained debris may lead to a variety of negative health effects including damage to the joint replacement. We describe a novel technique for the better containment and easier removal of third body debris during partial hardware removal. We demonstrate hardware removal on a hip joint model in the presence and absence of water-soluble gel to depict the reduction in metal debris volume and area of spread.

  11. Comparison of fiber reinforcement placed at different locations of pontic in interim fixed partial denture to prevent fracture: An in vitro study.

    PubMed

    Kapri, Surg Cdr Anita

    2015-01-01

    The interim restoration is an important phase in fixed prosthodontic therapy. It should provide sufficient durability to withstand the forces of mastication. A fractured interim restoration is damaging to the prosthodontic care and may lead to an unscheduled appointment for repair. Several attempts have been made to reinforce interim fixed partial dentures (FPDs). These have included the use of metal wire, a lingual cast metal reinforcement, a processed acrylic resin interim restoration, and different types of fibers, e.g., carbon, polyethylene, nylon and glass. These fibers can be placed in the occlusal, middle or cervical thirds in the FPD. There is no scientific data to evaluate the effect of fiber placement methods on the fracture resistance of clinical interim FPDs. Hence this study was designed to evaluate fracture load values of interim FPDs with different locations of fiber reinforcement. 30 interim FPD samples with polymethyl methacrylate (PMMA) reinforced with fibers at three different locations mainly occlusal, cervical and middle (10 samples each) were fabricated using a metal FPD on a master die. They were tested for fracture resistance in universal testing machine. The fracture resistance was recorded and is tabulated and analyzed statistically. The results showed that the placement of the reinforcement in the occlusal third of the pontic resulted in higher fracture resistance which was significantly higher (P < 0.05) than all other locations. The occlusal third of the pontic region from mesial to the distal end of the connector is the best site of placement of the fiber for reinforcing the PMMA interim restorative resin.

  12. The effect of different restorative and abutment materials on marginal and internal adaptation of three-unit cantilever implant-supported fixed partial dentures: an in vitro study.

    PubMed

    Kahramanoğlu, Erkut; Kulak-Özkan, Yasemin

    2013-12-01

    Passive fit is generally assumed to be a significant prerequisite for long-term implant success. The aim of this study was to evaluate the precision fit of three-unit implant-supported fixed partial dentures with different restorative and abutment materials on two implant systems: the Straumann and Astra Tech. Two mandibular epoxy resin models (one for each implant system) were fabricated, and two implants were inserted at the first and second molar region. Poly(vinyl siloxane) impression material was used to make the dental impression. For each implant system, fifteen models were fabricated, and each group was divided into three subgroups (group 1: titanium abutment with metal framework, group 2: titanium abutment with zirconium framework, group 3: zirconium abutment with zirconium framework). The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, totaling 1200 measurements for all groups. Data were evaluated statistically using ANOVA and LSD post hoc test (p < 0.05). The highest values at internal adaptation measurements were found at the occlusal surface for all groups. When the mean values of the marginal measurements were assessed, the lowest measurements were found in group 3 (51.416 μm), and the highest values were found in group 1 (79.394 μm). There were statistically significant differences between subgroups for marginal measurements (p < 0.05). As included in our study, marginal measurement values were found to be 46 to 87 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable. © 2013 by the American College of Prosthodontists.

  13. Clinical audit of posterior three-unit fixed-movable resin-bonded fixed partial dentures - A retrospective, preliminary clinical investigation.

    PubMed

    Botelho, Michael G; Dyson, John E; Mui, Thomas H F; Lam, Walter Y H

    2017-02-01

    Two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) have higher retention rates over longer span fixed-fixed RBFPDs. It has been hypothesized that interabutment stresses associated with fixed-fixed designs cause prosthesis debonds therefore for the replacement of molar-sized and longer spans, non-rigid connectors have been used to allow independent movement between two abutment teeth. This preliminary study evaluates the clinical longevity and subjects' satisfaction of three-unit fixed-movable (FM3) RBFPDs provided at a dental teaching hospital. Subjects who had received FM3 RBFPD(s) in the posterior region were clinically reviewed for complications. History of any debonds and subjects' satisfaction to the prosthesis was recorded. Time-to-debond (retention rate) and time-to-loss (survival rate) of these prostheses were presented in life tables. Ninety-eight prostheses in 84 subjects were examined. Their mean service life was 31.8 months (SD 11.5, range 3-67 months). Twenty-two prostheses had a history of debond, resulting in a retention proportion of 77.6%; seventeen of these were rebonded and still present at the time of review. One prosthesis was lost after extraction of a periodontally-involved abutment tooth, giving a survival proportion of 93.9%. High subject satisfaction and no adverse outcome were reported. Three-unit fixed-movable RBFPDs have a shorter success than two-unit cantilevered RBFPDs. However, non-rigid connectors allow the possibility of rebonding giving satisfactory short-term survival rate. Further research is needed to investigate their long-term efficacy. Three-unit fixed-movable RBFPDs incorporating non-rigid connectors may be a feasible option for replacement of molar-size pontic in the posterior region. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Simulation of multi-stage nonlinear bone remodeling induced by fixed partial dentures of different configurations: a comparative clinical and numerical study.

    PubMed

    Liao, Zhipeng; Yoda, Nobuhiro; Chen, Junning; Zheng, Keke; Sasaki, Keiichi; Swain, Michael V; Li, Qing

    2017-04-01

    This paper aimed to develop a clinically validated bone remodeling algorithm by integrating bone's dynamic properties in a multi-stage fashion based on a four-year clinical follow-up of implant treatment. The configurational effects of fixed partial dentures (FPDs) were explored using a multi-stage remodeling rule. Three-dimensional real-time occlusal loads during maximum voluntary clenching were measured with a piezoelectric force transducer and were incorporated into a computerized tomography-based finite element mandibular model. Virtual X-ray images were generated based on simulation and statistically correlated with clinical data using linear regressions. The strain energy density-driven remodeling parameters were regulated over the time frame considered. A linear single-stage bone remodeling algorithm, with a single set of constant remodeling parameters, was found to poorly fit with clinical data through linear regression (low [Formula: see text] and R), whereas a time-dependent multi-stage algorithm better simulated the remodeling process (high [Formula: see text] and R) against the clinical results. The three-implant-supported and distally cantilevered FPDs presented noticeable and continuous bone apposition, mainly adjacent to the cervical and apical regions. The bridged and mesially cantilevered FPDs showed bone resorption or no visible bone formation in some areas. Time-dependent variation of bone remodeling parameters is recommended to better correlate remodeling simulation with clinical follow-up. The position of FPD pontics plays a critical role in mechanobiological functionality and bone remodeling. Caution should be exercised when selecting the cantilever FPD due to the risk of overloading bone resorption.

  15. ALL-CERAMIC AND PORCELAIN-FUSED-TO-METAL FIXED PARTIAL DENTURES: A COMPARATIVE STUDY BY 2D FINITE ELEMENT ANALYSES

    PubMed Central

    Motta, Andréia Barreira; Pereira, Luiz Carlos; da Cunha, Andréia R.C.C

    2007-01-01

    All-ceramic fixed partial dentures (FPDs) have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1) metal-ceramic FPD; (2) All-ceramic FPD with the veneering porcelain on the occlusal and cervical surface of the abutment tooth; (3) All-ceramic FPD with the veneering porcelain only on the occlusal surface. A 100 N load was applied in an area of 0.5 mm2 on the working cusps, following these simulations: (1) on the abutment teeth and the pontic; (2) only on the abutment teeth; and (3) only on the pontic. Relative to the maximum stress values found for the physiological load, all-ceramic FPD with only occlusal veneering porcelain produced the lowest stress value (220 MPa), followed by all-ceramic FPD with cervical veneering porcelain (322 MPa) and metal-ceramic FPD (387 MPa). The stress distribution of the load applied on the abutments was significantly better compared to the other two load simulations. The highest principal stress values were low and limited in a small area for the three types of models under this load. When the load was applied on the pontic, the highest stress values appeared on the connector areas between the abutments and pontic. In conclusion, the best stress values and distribution were found for the all-ceramic FPD with the veneering porcelain only on the occlusal surface. However, in under clinical conditions, fatigue conditions and restoration defects must be considered. PMID:19089168

  16. Cement fixation and screw retention: parameters of passive fit. An in vitro study of three-unit implant-supported fixed partial dentures.

    PubMed

    Heckmann, Siegfried M; Karl, Matthias; Wichmann, Manfred G; Winter, Werner; Graef, Friedrich; Taylor, Thomas D

    2004-08-01

    It is generally assumed that passively fitting superstructures are a prerequisite for long-lasting implant success. In the study presented, the strain development of three-unit implant fixed partial dentures (FPDs) was evaluated at the bone surrounding the implant and on the superstructure using a strain gauge technique. Six groups of three-unit FPDs representing the commonly used techniques of bridge fabrication were investigated with 10 samples each, in order to quantify the influence of impression technique, mode of fabrication and retention mechanism on superstructure fit. Two ITI implants (Straumann, Waldenburg, Switzerland) were anchored in a measurement model according to a real-life patient situation and strain gauges were fixed mesially and distally adjacent to the implants and on the bridge pontics. The developing strains were recorded during cement setting and screw fixation. For statistical analysis, multivariate two sample tests were performed setting the level of significance at P=0.1. None of the investigated bridges revealed a truly passive fit without strains occurring. About 50% of the measured strains were found to be due to impression taking and model fabrication, whereas the remaining 50% were related to laboratory inaccuracies. The two impression techniques used did not reveal any significant differences in terms of precision. Both modes of fixation--i.e. cement and screw retention--provoked equally high stress levels. In the fabrication of screw-retained FPDs, similar results were obtained from the use of burn-out plastic copings and the technique of casting wax moulds to premachined components. Bonding bridge frames onto gold cylinders directly on the implants significantly reduces strain development.

  17. Comparison of fiber reinforcement placed at different locations of pontic in interim fixed partial denture to prevent fracture: An in vitro study

    PubMed Central

    Kapri, Surg Cdr Anita

    2015-01-01

    Background: The interim restoration is an important phase in fixed prosthodontic therapy. It should provide sufficient durability to withstand the forces of mastication. A fractured interim restoration is damaging to the prosthodontic care and may lead to an unscheduled appointment for repair. Several attempts have been made to reinforce interim fixed partial dentures (FPDs). These have included the use of metal wire, a lingual cast metal reinforcement, a processed acrylic resin interim restoration, and different types of fibers, e.g., carbon, polyethylene, nylon and glass. These fibers can be placed in the occlusal, middle or cervical thirds in the FPD. There is no scientific data to evaluate the effect of fiber placement methods on the fracture resistance of clinical interim FPDs. Purpose of the Study: Hence this study was designed to evaluate fracture load values of interim FPDs with different locations of fiber reinforcement. Materials and Methods: 30 interim FPD samples with polymethyl methacrylate (PMMA) reinforced with fibers at three different locations mainly occlusal, cervical and middle (10 samples each) were fabricated using a metal FPD on a master die. They were tested for fracture resistance in universal testing machine. Results: The fracture resistance was recorded and is tabulated and analyzed statistically. The results showed that the placement of the reinforcement in the occlusal third of the pontic resulted in higher fracture resistance which was significantly higher (P < 0.05) than all other locations. Conclusion: The occlusal third of the pontic region from mesial to the distal end of the connector is the best site of placement of the fiber for reinforcing the PMMA interim restorative resin. PMID:26929501

  18. In vivo wear of enamel by a lithia disilicate-based core ceramic used for posterior fixed partial dentures: first-year results.

    PubMed

    Esquivel-Upshaw, Josephine F; Young, Henry; Jones, Jack; Yang, Mark; Anusavice, Kenneth J

    2006-01-01

    This study aimed (1) to test the hypothesis that no significant relationship exists between the magnitude of occlusal clenching force and wear rates of enamel opposing a new core ceramic (e.max Press, Ivoclar Vivadent) used in posterior fixed partial dentures (FPDs); and (2) to test the hypothesis that mean annual enamel wear by an experimental core ceramic is comparable to the mean annual enamel wear by enamel of 38 microm. Baseline data were obtained for patients in addition to preliminary impressions of maxillary and mandibular teeth. Thirty ceramic FPDs were processed from a new core ceramic (e.max Press) that was hot pressed and glazed. Patients were recalled 1 year after cementation and evaluated using clinical criteria that included wear assessment of opposing teeth. Impressions were made of the opposing teeth with polyvinylsiloxane impression material and photographs were taken of intraoral occlusal contacts marked with articulating ribbon. Baseline casts and casts made at each recall exam of opposing dentitions were scanned using a 3-dimensional laser scanner (Laserscan 3D, Willytec) and evaluated for wear. A total of 21 occlusal surfaces were analyzed for the presence of wear. Statistical analysis using a linear and quadratic model revealed no significant relationship between occlusal forces and wear rate assuming either a linear model (R2 = 0.018) or a quadratic model (R2 = 0.023). The maximum annual wear of enamel by the glazed core ceramic (e.max Press) was 88.3 microm, which is significantly greater than the annual enamel-by-enamel wear of 38 microm (P < .0001). Further analysis with a larger sample size is needed to determine the relationship between occlusal clenching force and wear rate and the influence of other factors that cause increased wear of enamel by opposing ceramic restorations.

  19. [Evaluation of short-term clinical therapeutic efficiency of computer aided design and manufacturing titanium-ceramic-fixed partial dentures for implant-supported restoration in posterior region].

    PubMed

    Wu, Min-Jie; Zou, Li-Dong; Xu, Wei-Hua; Zhang, Xiang-Hao

    2013-10-18

    To evaluate the clinical results of computer aided design and computer aided manufacturing (CAD/CAM) titanium-ceramic-fixed partial dentures for implant-supported restoration in posterior region. In the study, 90 patients (47 males, 43 females, and the mean age of 48.7 years ranging from 30-62 years) with posterior tooth missing underwent implant-supported porcelain fuse mental prostheses with CAD/CAM titanium-base. A total of 135 prostheses (159 prosthetic units) were fabricated, and 152 implants were placed. The evaluators examined the integrity of restoration, gingival health, color match and marginal adaptation. The mean follow-up time was 51.9 months (24-80 months). No implant was lost during the loading time. All the patients were satisfied at the end of their treatment. The chipping rate of porcelain fuse mental prostheses with CAD/CAM titanium-base was 13.2%(21/159 prosthetic units), No fracture of titanium-base was observed, and 7.4% (10/135) prostheses were found loosening. The authors rated 97.8% (132/135) prosthesis as good or better in regard to color match, 100% (152/152) implants had excellent marginal adaptation. The implant-supported titanium-based porcelain fuse mental prostheses with CAD/CAM show good marginal integrity and shade stability, with a clinically acceptable chipping rate, and these restorations can achieve success in the case of posterior tooth missing. Further study is needed to determine the long-term results.

  20. Success, clinical performance and patient satisfaction of direct fibre-reinforced composite fixed partial dentures - a two-year clinical study.

    PubMed

    Malmstrom, H; Dellanzo-Savu, A; Xiao, J; Feng, C; Jabeen, A; Romero, M; Huang, J; Ren, Y; Yunker, M A

    2015-12-01

    To evaluate the success, clinical performance and patient satisfaction of directly placed fibre-reinforced composite (FRC) fixed partial dentures (FPDs) in 2 years. One hundred sixty-seven FRC FPDs (120 subjects) were directly fabricated to restore a single missing tooth by six Advanced Education in General Dentistry (AEGD) residents. The FRC FPDs recipients were randomised into two groups according to the fibre materials (pre-impregnated glass or polyethylene). Clinical performance was evaluated at baseline (2 weeks), 6, 12 and 24 months by two calibrated evaluators for prosthesis adaptation, colour match, marginal discoloration, surface roughness, caries and post-operative sensitivity using modified United State Public Health Service (USPHS) criteria. Prosthesis appearance, colour, chewing ability and overall satisfaction were evaluated by patients using a visual analogue scale (VAS). Kaplan-Meier estimation was used to estimate the prosthesis success. Ninety-four patients with 137 FRC FPDs returned (21·67% attrition rate for study subjects, 17·94% for FRC FPDs). Seventeen FRC FPDs failed, due to one-end (n = 4) or two-ends (n = 4) debonding or pontic fracture (n = 9). The cumulative 2-year success rate was 84·32% and survival rate was 92·7%; there were no statistically significant differences between the groups according to different missing tooth location, retention type or fibre materials (P > 0·05). Patient satisfaction regarding prosthesis appearance, col-our, chewing ability and overall satisfaction was rated high on the VAS (mean >80 mm) for all criteria at all time points. The FRC FPDs (restoring single tooth) fabricated by AEGD residents achieved acceptable success and survival rates in a 2-year follow-up. © 2015 John Wiley & Sons Ltd.

  1. Denture use and the technical quality of dental prostheses among persons 18-74 years of age: United States, 1988-1991.

    PubMed

    Redford, M; Drury, T F; Kingman, A; Brown, L J

    1996-02-01

    For persons without all or some of their natural teeth in one or both arches, the use of a complete or partial denture and the quality of the denture used are important aspects of their oral health and functioning. This report of prosthodontic findings from the first three years of the 1988-94 National Health and Nutrition Examination Survey (NHANES III-Phase 1) provides estimates of denture use among the US civilian non-institutionalized population 18-74 years of age, as well as seminal information on the technical quality of dental prostheses nationwide. NHANES III-Phase 1 prosthodontic findings indicated that about one in five persons 18-74 years of age wears a removable prosthodontic appliance of some type. Overall, removable prosthodontic appliances are worn disproportionately more often by women than by men, and less frequently by whites than by blacks. Comparisons among race-ethnicity categories indicate that Mexican-Americans are less likely to use dentures than either of their non-Hispanic counterparts. Analyses of prosthodontic evaluation data indicated that approximately 60% of denture users have at least one problem with a denture. These findings from the oral component of NHANES III-Phase 1 provide clear indications that, despite increasing trends in tooth retention, dependence on removable prosthodontic appliances is still a reality of life for millions of Americans.

  2. Surface roughness and internal porosity of partial removable dental prosthesis frameworks fabricated from conventional wax and light-polymerized patterns: a comparative study.

    PubMed

    Swelem, Amal Ali; Abdelnabi, Mohamed Hussein; Al-Dharrab, Ayman A; AbdelMaguid, Hanan Fouad

    2014-04-01

    Surface roughness and internal porosity are 2 potential risk factors that threaten the biocompatibility and long-term mechanical stability of cast partial removable dental prostheses frameworks. The purpose of this study was to investigate the influence of the material, of conventional wax patterns, and the recently introduced light-polymerized patterns on the initial surface roughness and internal porosity of the cobalt-chromium castings of partial removable dental prostheses. Twenty-eight identical partial removable dental prosthesis frameworks were fabricated on a cast of a maxillary Kennedy Class III modification 1 partially edentulous patient. Fourteen frameworks were fabricated from each pattern material. The initial surface roughness, Ra (μm), of the resultant castings was measured with a profilometer. Radiographs of the castings were made on dental occlusal films with a dental x-ray unit with the following exposure conditions: tube voltage 70 kV; exposure time 1.0 seconds; tube current 7 mA; and source-film distance 35 cm. The number and size of porosities in the 3 main components (clasp units, major connectors, denture base meshwork) were assessed. Statistical analysis was conducted with the independent sample t test for surface roughness and the Mann Whitney test for internal porosity (α=.05). The statistical analysis of mean surface roughness and internal porosity revealed no significant difference between the 2 groups. The surface roughness and internal porosity of frameworks fabricated from conventional wax and Liwa patterns were comparable, with no significant differences between the 2 pattern materials. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  3. 30 CFR 250.1730 - When might MMS approve partial structure removal or toppling in place?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... partial structure removal or toppling in place for conversion to an artificial reef if you meet the following conditions: (a) The structure becomes part of a State artificial reef program, and the...

  4. Dentures are a Reservoir for Respiratory Pathogens.

    PubMed

    O'Donnell, Lindsay E; Smith, Karen; Williams, Craig; Nile, Chris J; Lappin, David F; Bradshaw, David; Lambert, Margaret; Robertson, Douglas P; Bagg, Jeremy; Hannah, Victoria; Ramage, Gordon

    2016-02-01

    Recent studies have established a relationship between dental plaque and pulmonary infection, particularly in elderly individuals. Given that approximately one in five adults in the UK currently wears a denture, there remains a gap in our understanding of the direct implications of denture plaque on systemic health. The aim of this study was to undertake a comprehensive evaluation of putative respiratory pathogens residing upon dentures using a targeted quantitative molecular approach. One hundred and thirty patients' dentures were sonicated to remove denture plaque biofilm from the surface. DNA was extracted from the samples and was assessed for the presence of respiratory pathogens by quantitative polymerase chain reaction (qPCR). Ct values were then used to approximate the number of corresponding colony forming equivalents (CFEs) based on standard curves. Of the dentures, 64.6% were colonized by known respiratory pathogens. Six species were identified: Streptococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae B, Streptococcus pyogenes, and Moraxella catarrhalis. P. aeruginosa was the most abundant species followed by S. pneumoniae and S. aureus in terms of average CFE and overall proportion of denture plaque. Of the participants, 37% suffered from denture stomatitis; however, there were no significant differences in the prevalence of respiratory pathogens on dentures between healthy and inflamed mouths. Our findings indicate that dentures can act as a reservoir for potential respiratory pathogens in the oral cavity, thus increasing the theoretical risk of developing aspiration pneumonia. Implementation of routine denture hygiene practices could help to reduce the risk of respiratory infection among the elderly population. © 2015 by the American College of Prosthodontists.

  5. What Are Dentures?

    MedlinePlus

    ... Know About Puberty Train Your Temper What Are Dentures? KidsHealth > For Kids > What Are Dentures? Print A A A en español ¿Qué son ... to be pulled — an older person might need dentures (say: DEN-churs). Dentures are a set of ...

  6. Improved Prefrontal Activity and Chewing Performance as Function of Wearing Denture in Partially Edentulous Elderly Individuals: Functional Near-Infrared Spectroscopy Study

    PubMed Central

    Kamiya, Kazunobu; Narita, Noriyuki; Iwaki, Sunao

    2016-01-01

    The purpose of this study was to elucidate the effects of wearing a denture on prefrontal activity during chewing performance. We specifically examined that activity in 12 elderly edentulous subjects [63.1±6.1 years old (mean ± SD)] and 12 young healthy controls (22.1±2.3 years old) using functional near-infrared spectroscopy (fNIRS) in order to evaluate the quality of prefrontal functionality during chewing performance under the conditions of wearing a denture and tooth loss, and then compared the findings with those of young healthy controls. fNIRS and electromyography were used simultaneously to detect prefrontal and masticatory muscle activities during chewing, while occlusal force and masticatory score were also examined by use of a food intake questionnaire. A significant increase in prefrontal activity was observed during chewing while wearing a denture, which was accompanied by increased masticatory muscle activity, occlusal force, and masticatory score, as compared with the tooth loss condition. Prefrontal activation during chewing while wearing a denture in the elderly subjects was not much different from that in the young controls. In contrast, tooth loss in the elderly group resulted in marked prefrontal deactivation, accompanied by decreased masticatory muscle activity, occlusal force, and masticatory score, as compared with the young controls. We concluded that intrinsic prefrontal activation during chewing with a denture may prevent prefrontal depression induced by tooth loss in elderly edentulous patients. PMID:27362255

  7. Condition of live fire-scarred ponderosa pine eleven years after removing partial cross-sections

    Treesearch

    Emily K. Heyerdahl; Steven J. McKay

    2008-01-01

    Our objective is to report mortality rates for ponderosa pine trees in Oregon ten to eleven years after removing a fire-scarred partial cross-section from them, and five years after an initial survey of post-sampling mortality. We surveyed 138 live trees from which we removed fire-scarred partial crosssections in 1994/95 and 387 similarly sized, unsampled neighbor...

  8. Microcystic ganglioglioma treated by partial removal and radiation therapy

    SciTech Connect

    Cox, J.D.; Zimmerman, H.M.; Haughton, V.M.

    1982-08-01

    A 35-year old woman presented with visual hyperacuity and seizures. Radionuclide and CT scans revealed a frontal lobe mass lesion consistent with an astrocytoma. Subtotal removal was necessary due to proximity of the tumor to the motor strip. Initial histopathologic interpretation was malignant glioma (astrocytoma Grade 2 or 3). Megavoltage irradiation was delivered to a midsagittal dose of 6300 rad in seven weeks. Subsequent review of the slides revealed the tumor to be a microcystic ganglioglioma. The patient is well five and one-half years after treatment. It is important to separate these low grade neoplasms from the more ominous astrocytomas in regard to prognosis after resection and irradiation.

  9. Glass fibre reinforced acrylic resin complete dentures: a 5-year clinical study.

    PubMed

    Goguţă, Luciana Maria; Bratu, Dorin; Jivănescu, Anca; Erimescu, Raluca; Mărcăuţeanu, Corina

    2012-03-01

    The aim of the study was to establish the wear resistance of the glass fiber reinforced complete dentures comparative to the traditional acrylic complete dentures. Complete new dentures were made to replace old fractured 'un'-reinforced acrylic dentures. The total number of dentures was 30 and woven E-glass fibre reinforcements were used in maxillary complete dentures. Unidirectional E-glass fibre reinforcements were used as partial fibre reinforcements in mandibular complete dentures. Ten complete acrylic un-reinforced dentures were used as control. The follow-up period was 5 years and the recalls were made at 6 months. After 5 years of wearing the new dentures, the control dentures suffered seven fractures. After 5 years all the mandibular reinforced dentures were in good shape. The maxillary complete reinforced dentures suffered four partial fractures. Fracture lines were restricted by the glass fibre net and the patients could still use their dentures. Pre-impregnated E-glass fibre nets and polymer pre-impregnated E-glass unidirectional fibres are useful in reinforcing acrylic resin complete dentures especially were heavy occlusal forces are involved. Glass fibre reinforcement will be applied on the tension side in both cases (total fibre reinforcement and partial fibre reinforcement). The reinforcement cannot replace the necessary linings and occlusal adjustments. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  10. Retrospective analysis of porcelain failures of metal ceramic crowns and fixed partial dentures supported by 729 implants in 152 patients: patient-specific and implant-specific predictors of ceramic failure.

    PubMed

    Kinsel, Richard P; Lin, Dongming

    2009-06-01

    Porcelain fracture associated with an implant-supported, metal ceramic crown or fixed partial denture occurs at a higher rate than in tooth-supported restorations, according to the literature. Implant-specific and patient-specific causes of ceramic failure have not been fully evaluated. The purpose of this retrospective study was to evaluate the potential statistical predictors for porcelain fracture of implant-supported, metal ceramic restorations. Over a 6-month period, a consecutive series of patients having previously received implant-supported, metal ceramic fixed restorations were examined during periodic recall appointments. The number of supporting implants, number of dental units, type of restoration, date of prosthesis insertion, location in the dental arch, opposing dentition, type of occlusion, presence of parafunctional habits, use of an occlusal protective device, presence or absence of ceramic fractures, gender, and age were recorded for each patient. The generalized estimating equation (GEE) approach was used for the intrasubject correlated measurements analysis of categorical outcomes (presence or absence of ceramic fractures) to determine which patient- and implant-specific factors would predict porcelain fracture (alpha=.05). Data were collected from 152 patients representing 998 dental units (390 single crowns and 94 fixed partial dentures) supported by 729 implants. Porcelain fractures of 94 dental units occurred in 35 patients. The fractures were significantly (P<.05) associated with opposing implant-supported metal ceramic restorations, bruxism, and not wearing a protective occlusal device. Metal ceramic prostheses (single crown or fixed partial dentures) had approximately 7 times higher odds of porcelain fracture (odds ratio (OR)=7.06; 95% confidence interval (CI): 2.57 to 19.37) and 13 times greater odds of a fracture requiring either repair or replacement (OR=13.95; 95% CI: 2.25 to 86.41) when in occlusion with another implant

  11. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification. An OTC denture cleanser is a device that consists of material in the form of a powder, tablet, or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or...

  12. [Experimental basis of a new material for the manufacture of bases dentures].

    PubMed

    Shturminskiĭ, V G

    2013-10-01

    The author studied the problem of improving the quality of prosthetic removable prostheses through the development of new basic material based on polypropylene copolymer. To this end, we examined the physical and chemical structure and hygienic properties of the produced material. The studies found that the developed material of polypropylene optimal solution for the partial plate denture bases, without flaws acrylic prosthesis and improves the properties of the previously used polypropylene plastics.

  13. Knowledge, attitude, and practice of dental professionals regarding the effect and management of food impaction associated with fixed partial denture prostheses: A survey.

    PubMed

    Nagarsekar, Aradhana; Gaunkar, Ridhima; Aras, Meena

    2016-01-01

    This survey was undertaken to assess dentist's opinion regarding the occurrence and pattern of food impaction in relation to fixed partial denture (FPD) prostheses, its commonly observed consequences, factors contributing to it, and its management. A descriptive survey was conducted on a sample size of 150 dental practitioners. The pro forma consisted of informed consent, demographic information, and questionnaire. The results were tallied and quantitative analysis was performed to obtain the descriptive statistics for the data using SPSS version 20. All the study respondents had come across patients who complained of food impaction in relation to FPD. The most common consequences of food impaction were proximal caries of the adjacent teeth and interdental bone loss. Majority of the dentists considered faulty FPD design with improper contact relation, improper crown contour, poor margin adaptation, and faulty pontic design as the most likely reason for food impaction. Repeating the FPD with emphasis on prescribing and reinforcing the use of proper interdental aids was considered as the ideal treatment option. It was also observed that about half of the dentists always communicated inadequate information of the FPD prostheses that needed replacement to the dental laboratory technician for the successive bridge. Most of the times, prosthodontists were consulted to rectify the problem of food impaction resulting from faulty FPD prostheses. However, it is obvious that it is easier and more prudent to prevent rather than treat food impaction. This study gives an overview of some of the common errors in designing the FPD prostheses which often lead to food impaction and measures to be taken to overcome them. It may be concluded as all the dentists participating in the survey agreed that food impaction is one of the common complaint among FPD Patients. Proximal caries and interdental bone loss were the prevalent outcomes of food impaction. Faulty FPD design was allegedly

  14. Knowledge, attitude, and practice of dental professionals regarding the effect and management of food impaction associated with fixed partial denture prostheses: A survey

    PubMed Central

    Nagarsekar, Aradhana; Gaunkar, Ridhima; Aras, Meena

    2016-01-01

    Objective: This survey was undertaken to assess dentist's opinion regarding the occurrence and pattern of food impaction in relation to fixed partial denture (FPD) prostheses, its commonly observed consequences, factors contributing to it, and its management. Methods: A descriptive survey was conducted on a sample size of 150 dental practitioners. The pro forma consisted of informed consent, demographic information, and questionnaire. The results were tallied and quantitative analysis was performed to obtain the descriptive statistics for the data using SPSS version 20. Results and Interpretation: All the study respondents had come across patients who complained of food impaction in relation to FPD. The most common consequences of food impaction were proximal caries of the adjacent teeth and interdental bone loss. Majority of the dentists considered faulty FPD design with improper contact relation, improper crown contour, poor margin adaptation, and faulty pontic design as the most likely reason for food impaction. Repeating the FPD with emphasis on prescribing and reinforcing the use of proper interdental aids was considered as the ideal treatment option. It was also observed that about half of the dentists always communicated inadequate information of the FPD prostheses that needed replacement to the dental laboratory technician for the successive bridge. Most of the times, prosthodontists were consulted to rectify the problem of food impaction resulting from faulty FPD prostheses. However, it is obvious that it is easier and more prudent to prevent rather than treat food impaction. This study gives an overview of some of the common errors in designing the FPD prostheses which often lead to food impaction and measures to be taken to overcome them. Conclusion: It may be concluded as all the dentists participating in the survey agreed that food impaction is one of the common complaint among FPD Patients. Proximal caries and interdental bone loss were the prevalent

  15. [Contemporary methods and mobile denture cleansers and theirs significance for older population].

    PubMed

    Strajnić, Ljiljana; Dokić, Miodrag; Vucinić, Predrag

    2011-01-01

    A dramatic increase in the number of people living in their seventies, eighties and nineties is associated with a loss of teeth and the use of mobile dentures. The aim of this paper was to highlight the consequences of poor denture hygiene on oral and general health in vulnerable elderly people, in long-term hospitalized elderly patients and in long-term institutionalized elderly in nursing homes. DENTURE DEPOSITS AND CONSEQUENCES OF POOR DENTURE HYGIENE: The number of bacteria living in the mouth is getting larger after putting denture on. Namely, a small "space" develops between jaw and denture, creating perfect conditions for bacterial growth. Denture becomes a "reservoir" of micro-organisms. Denture deposits such as bacterial plaque, fungi, tartar and remnants could be responsible for stomatitis prothetica, cheilitis angularis, inflammatory fibrous hyperplasia, halitosis (bad breath), dental caries in mobile denture carriers, mucositis and periimplantitis in mobile implant over-dentures carriers, accelerated destruction of denture materials for underlying, such as denture base soft liners, respiratory airways diseases, bacterial endocarditis and gastrointestinal infections. REMOVAL OF DENTURE DEPOSITS: It is recommendable to combine mechanical and chemical denture cleaning. Denture submersion into a commercial cleansing solution for less than one hour is an effective cleaning method. Commercial cleanser: specifically intended for dentures with metal parts should be used for those dentures. Commercial cleansers with a new component of silicon polymer, whose thin layer surrounds all denture surfaces and disables oral bacteria to agglomerate, are effective and useful. Preventive hygienic treatments are very important in hospitals and homes for the aged, bearing in mind that old and ill persons reside here. Those institutions are recommended to get equipped with ultrasound denture cleaners. IMPORTANCE OF WRITTEN BROCHURE ON PROPER DENTURE HYGIENE: Patients should

  16. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification. An... that is intended to remove debris from removable prosthetic dental appliances, such as bridges...

  17. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification. An... that is intended to remove debris from removable prosthetic dental appliances, such as bridges...

  18. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification. An... that is intended to remove debris from removable prosthetic dental appliances, such as bridges...

  19. 21 CFR 872.3520 - OTC denture cleanser.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification. An... that is intended to remove debris from removable prosthetic dental appliances, such as bridges...

  20. Review of adhesive techniques used in removable prosthodontic practice.

    PubMed

    Shimizu, Hiroshi; Takahashi, Yutaka

    2012-09-01

    There are several benefits in using adhesive technique in removable prosthodontics as well as fixed prosthodontics. Previous studies have examined denture-base surface treatments that improve bond strength between a denture base resin and autopolymerizing repair resin. Dichloromethane and ethyl acetate are organic solvents that swell the denture base surface, thereby permitting diffusion of the acrylic resin. The optimal treatment duration is 5-10 s for dichloromethane and 120 s for ethyl acetate. It was reported that the bond durability of dichloromethane was superiorto that of ethyl acetate. Bonding between metal components and the denture base resin has an important role in the longevity of removable prostheses. The combination of metal conditioners and alumina air-abrasion is effective in fabricating and repairing removable dentures. Acidic monomers (4-META and MDP) are appropriate for base metal alloys, including Co-Cr alloy and titanium alloy, while thione monomers (MTU-6 and VBATDT) are suitable for noble metal alloys such as gold alloy and silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy. As an alternative to conventional restorations, resin-bonded restorations can provide precisely parallel guide planes with well-made rest seats. Careful consideration should be paid to stabilizing loosened teeth by fixing them with resin-bonded splints or fixed partial dentures.

  1. Dentures - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Dentures URL of this page: https://medlineplus.gov/languages/dentures.html Other topics A-Z Expand Section ...

  2. Internal porosity of cast titanium removable partial dentures: influence of sprue direction and diameter on porosity in simplified circumferential clasps.

    PubMed

    Baltag, Ioana; Watanabe, Kouichi; Miyakawa, Osamu

    2005-06-01

    The behavior of molten titanium in molds of complicated shape is still insufficiently understood; consequently, definite spruing criteria are not yet available for titanium RPD frameworks. This study investigated the influence of sprue design on porosity in pressure-cast titanium circumferential clasps. The patterns of 90 circumferential clasps were sprued with three directions (0, 30 and 60 degrees , as measured between the sprue and the symmetry plane of the clasp assembly) and three sprue diameters (1.5, 2.0 and 2.5mm). CPTi was cast in a one-chamber pressure casting machine. Pore number and size were assessed on radiographs of the castings. Statistical analysis was done by two-way analysis of variance (ANOVA), followed by Fisher's PLSD post hoc test. The porosity in lingual arms increased significantly with increase of sprue diameter and sprue angle, while the porosity in minor connectors had an inversely proportional distribution. Very low porosity, uninfluenced by sprue design, was found in buccal arms. In conclusion, internal porosity in titanium circumferential clasp arms can be minimized through sprue design: the 0 degrees sprue direction produced the least porosity, while for the 30 and 60 degrees directions, 1.5mm diameter sprues produced lower porosity than 2.0 and 2.5mm diameter sprues. In this study, the lowest porosity in titanium circumferential clasp arms was obtained with sprues attached perpendicularly to the minor connectors, regardless of sprue diameter. Conventional sprue directions produced significantly higher porosity in clasp lingual arms, the amount of porosity increasing with sprue diameter.

  3. Teaching complete dentures.

    PubMed

    Lechner, S K

    1993-01-01

    Success in wearing complete denture depends, in order of importance, on motivation, neuromuscular control and technical considerations. To address the two aspects of motivation and neuromuscular control, fourth year students at Sydney University are taught a protocol which encompasses duplication of the patient's existing denture and modification of this duplicate to satisfy the patient's needs and wants. This modified duplicate denture acts as a diagnostic prototype which is used as a guide during construction of the new denture.

  4. Using a Visible Light-Polymerized Resin to Fabricate an Interim Partial Removable Dental Prosthesis.

    PubMed

    Segal, Aaron; Yu, Hui Wen; Elkassaby, Heba

    2017-02-01

    An interim partial removable dental prosthesis (RDP) is any dental prosthesis that replaces some teeth in a partially dentate arch designed to enhance esthetics, stabilization, and/or function for a limited period of time, after which it is to be replaced by a definitive dental prosthesis. This article describes a technique that uses a visible light-polymerized (VLP) resin as the base material for an interim partial RDP. This technique can be easily accomplished in a dental office or laboratory and results in a predictable dental prosthesis. This technique eliminates the need for laboratory processing.

  5. The effects of denture status on nutrition.

    PubMed

    Papas, A S; Palmer, C A; Rounds, M C; Russell, R M

    1998-01-01

    In Part I of this study, the Human Nutrition Research Center of the United States Department of Agriculture's Nutritional Status Study (NSS) of 691 independently living elderly people aged 60-98 found that poor dietary quality was associated with low educational attainment, low median family income, and self-report of partial or full dentures. In Part II, further analysis was conducted on a random subsample of 181 subjects who were examined and divided into four groups according to dentate status: two dentures, one denture, partial dentures, and teeth. In this subgroup, significant correlations were found between the quality of nutrient intake and the degree of edentulousness. Analysis of 53 nutrients plus calories from three-day food records showed a significantly higher nutritional quality of the diet in dentate volunteers than in the other groups. This difference was approximately 20% for 19 nutrients, bringing some nutrients (such as calcium) below the RDA for this age group. Although direct correlations cannot be made with actual nutritional status, the introduction of dentures could further compromise the precarious nutritional intake of the elderly population. With this in mind, dentists need to consider carefully the importance of their elderly patients maintaining at least some natural dentition and should provide adequate information on nutritional adaptations to dentures.

  6. Effects of complete dentures on respiratory performance: spirometric evaluation.

    PubMed

    Piskin, Bulent; Sipahi, Cumhur; Karakoc, Omer; Atay, Arzu; Ciftci, Faruk; Tasci, Canturk; Akin, Hakan; Arisan, Volkan; Sevketbeyoglu, Haldun; Turker, Turker

    2014-03-01

    There is a lack of data regarding whether edentulous subjects should remove dentures during spirometric measurements or not. The purpose of this study is to determine influences of complete dentures on spirometric parameters in edentulous subjects. A total of 46 complete denture wearers were included in this study. Respiratory functions of the subjects were evaluated by spirometric tests that were performed in four different oral conditions: without dentures (WOD), with dentures, lower denture only and upper denture only. Forced vital capacity (FVC), peak expiratory flow, forced expiratory volume in 1 s and forced expiratory flow between 25% and 75% were evaluated. The data were analyzed with Friedman, Wilcoxon and paired-samples t tests (α = 0.05). Significant differences were found between spirometric parameters in different oral conditions (p < 0.05). In all spirometric parameters, the most important significant differences were found between conditions WOD, FVC and with lower dentures (FVC), and WOD (forced expiratory volume in 1 s) and with upper dentures (forced expiratory volume in 1 s) (p < 0.001). It was observed that complete dentures may unfavourably affect spirometric values of edentulous subjects. However, current findings need to be confirmed with advanced respiratory function tests. © 2012 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  7. Low temperature biological phosphorus removal and partial nitrification in a pilot sequencing batch reactor system.

    PubMed

    Yuan, Qiuyan; Oleszkiewicz, Jan A

    2011-01-01

    Partial nitrification and biological phosphorus removal appear to hold promise of a cost-effective and sustainable biological nutrient removal process. Pilot sequencing batch reactors (SBRs) were operated under anaerobic/aerobic configuration for 8 months. It was found that biological phosphorus removal can be achieved in an SBR system, along with the partial nitrification process. Sufficient volatile fatty acids supply was the key for enhanced biological phosphorus removal. This experiment demonstrated that partial nitrification can be achieved even at low temperature with high dissolved oxygen (>3 mg/L) concentration. Shorter solid retention time (SRT) for nitrite oxidizing bacteria (NOB) than for ammonia oxidizing bacteria due to the nitrite substrate limitation at the beginning of the aeration cycle was the reason that caused NOB wash-out. Controlling SRT should be the strategy for an SBR operated in cold climate to achieve partial nitrification. It was also found that the aerobic phosphorus accumulating organisms' P-uptake was more sensitive to nitrite inhibition than the process of anaerobic P-release.

  8. Iatrogenic Damage to the Periodontium Caused by Removable Prosthodontic Treatment Procedures: An Overview

    PubMed Central

    Hussain, Khaja Amjad; Azzeghaibi, Saleh Nasser; Tarakji, Bassel; R. S, SenthilRajan; Sirajuddin, Syed; Prabhu, Sandeep S

    2015-01-01

    As the number of aged people in the world is growing, the need to provide patients with tooth alternate through removable partial dentures is equally growing. There are adversarial effects that should be kept in mind which might disturb the remaining teeth; specially, the abutments and the supporting tissues. These effects might spread to the muscles of mastication and also to the supporting periodontal tissues. Thus, we should plan removable partial dentures (RPDs) without mutilation to the adjacent teeth or the underlying tissues. PMID:26312084

  9. Partial Nitrification and Denitrifying Phosphorus Removal in a Pilot-Scale ABR/MBR Combined Process.

    PubMed

    Wu, Peng; Xu, Lezhong; Wang, Jianfang; Huang, Zhenxing; Zhang, Jiachao; Shen, Yaoliang

    2015-11-01

    A pilot-scale combined process consisting of an anaerobic baffled reactor (ABR) and an aerobic membrane bioreactor (MBR) for the purpose of achieving easy management, low energy demands, and high efficiencies on nutrient removal from municipal wastewater was investigated. The process operated at room temperature with hydraulic retention time (HRT) of 7.5 h, recycle ratio 1 of 200%, recycle ratio 2 of 100%, and dissolved oxygen (DO) of 1 mg/L and achieved good effluent quality with chemical oxygen demand (COD) of 25 mg/L, NH4 (+)-N of 4 mg/L, total nitrogen (TN) of 11 mg/L, and total phosphorus (TP) of 0.7 mg/L. The MBR achieved partial nitrification, and NO2 (-)-N has been accumulated (4 mg/L). Efficient short-cut denitrification was occurred in the ABR with a TN removal efficiency of 51%, while the role of denitrification and phosphorus removal removed partial TN (14%). Furthermore, nitrogen was further removed (11%) by simultaneous nitrification and denitrification in the MBR. In addition, phosphorus accumulating organisms in the MBR sufficiently uptake phosphorus; thus, effluent TP further reduced with a TP removal efficiency of 84%. Analysis of fluorescence in situ hybridization (FISH) showed that ammonia oxidizing bacteria (AOB) and phosphorus accumulating organisms (PAOs) were enriched in the process. In addition, the accumulation of NO2 (-)-N was contributed to the inhibition on the activities of the NOB rather than its elimination.

  10. The Shape Interaction Matrix-Based Affine Invariant Mismatch Removal for Partial-Duplicate Image Search.

    PubMed

    Lin, Yang; Lin, Zhouchen; Zha, Hongbin

    2017-02-01

    Mismatch removal is a key step in many computer vision problems. In this paper, we handle the mismatch removal problem by adopting shape interaction matrix (SIM). Given the homogeneous coordinates of the two corresponding point sets, we first compute the SIMs of the two point sets. Then, we detect the mismatches by picking out the most different entries between the two SIMs. Even under strong affine transformations, outliers, noises, and burstiness, our method can still work well. Actually, this paper is the first non-iterative mismatch removal method that achieves affine invariance. Extensive results on synthetic 2D points matching data sets and real image matching data sets verify the effectiveness, efficiency, and robustness of our method in removing mismatches. Moreover, when applied to partial-duplicate image search, our method reaches higher retrieval precisions with shorter time cost compared with the state-of-the-art geometric verification methods.

  11. Influence of the Ethnic Affiliation, Level of Education and Place of Living on Oral Health at Geriatric Population with Total and Partial Dentures in Republic of Macedonia.

    PubMed

    Stavreva, Natasha; Guguvcevchi, Ljuben; Kapusevska, Biljana

    2015-01-01

    Health is the main component of the quality of life, while oral health is component of the general health. The socio-demographic characteristics are one of the important factors for perception of the oral health and the quality of life. The main purpose of this study was to perform an evaluation of the quality of life of geriatric patients (older than 65) with built-in oral prosthetic dentures depending on the ethnic affiliation, level of education and place of living, as socio-demographic characteristics. The survey was a prospective transversal (cross-sectional) study conducted among 165 institutionally sheltered patients at the Gerontology Institute (inspected group - IG) and 170 patients from the dental specialist clinics (control group CG) at the age of 65 and older. The statistical program SPSS for Windows ver. 13.0 was used for statistical processing. Patients with upper and lower total dentures dominated (43.6% vs. 26.5%). The highest GOHAI score had the other ethnicities of IC (32.08) and Roma of IG (31.00), while the lowest was in the Albanians of CG (25.91). The highest value of 30.15 had the IG of patients living in urban areas. The quality of life and oral health of the geriatric patients are at unsatisfactory level, with significant influence of the place of living and insignificant influence of the ethnic affiliation and level of education.

  12. Condition of live fire-scarred ponderosa pine trees six years after removing partial cross sections

    Treesearch

    Emily K. Heyerdahl; Steven J. McKay

    2001-01-01

    Our objective was to document the effect of fire-history sampling on the mortality of mature ponderosa pine trees in Oregon. We examined 138 trees from which fire-scarred partial cross sections had been removed five to six years earlier, and 386 similarly sized, unsampled neighbor trees, from 78 plots distributed over about 5,000 ha. Mortality was low for both groups....

  13. On denture marking.

    PubMed

    Borrman, H I; DiZinno, J A; Wasén, J; René, N

    1999-06-01

    During the last decades in Sweden dentures have been permanently marked with a stainless steel metal band incorporated into the acrylic and containing the patient's birth date, a special number, and "S" for Sweden. The last recommendation issued by the National Board of Health and Welfare states that "the patients shall always be offered denture marking and be informed about the benefit thereof. Denture marking is not permitted if the patient refuses it". Requirements for denture markers have been that they should be biologically inert (when incorporated into the denture), not be expensive, be easy to inscribe, be possible to retrieve after an accident, and survive elevated temperatures for a reasonable time under normal circumstances. Although the frequency of edentulousness has decreased in recent years due to the improvement in oral health there remains a need to address the issue of marking of complete dentures, because there is a large variation in the oral status of populations in different countries. Given that only one marked denture can reveal the identity of a deceased person when all other methods fail to do so, makes it worthwhile. Furthermore, denture marking is important in long-term care facilities. We have investigated the issue of denture marking in Europe and in the United States. The results from the European survey show that denture marking is, to our knowledge regulated by law only in Sweden and Iceland. In the US denture marking is so far mandatory in 21 states while New York State requires dentures to be marked if the patient requests it and several other states impose the obligation to mark dentures on long-term care facilities. Since there is no international consensus regarding the issue of denture marking it is important to address it. A survey from the Nordic countries has shown that if denture marking was in general use, the contribution to the establishment of identity by forensic odontology in cases of fire would increase by about 10

  14. Prosthetic rehabilitation of a patient after a partial mandibulectomy

    PubMed Central

    Goiato, Marcelo Coelho; de Medeiros, Rodrigo Antonio; Vechiato Filho, Aljomar José; da Silva, Emily Vivianne Freitas; Sônego, Mariana Vilela; de Carvalho, Karina Helga Turcio; Guiotti, Aimée Maria; de Carvalho Dekon, Stefan Fiuza; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline

    2015-01-01

    Introduction The treatment of orofacial tumors may cause facial deformities by losses of structures that affect basic functions, i.e. feeding, speech, and the reduction of patient self-steam. Presentation of case A white male patient was diagnosed with epidermoid cancer on the mandibular alveolar ridge with infiltration staging IV A. The patient was submitted to a mandibulectomy associated with a complete extraction of mandibular teeth. For rehabilitation, a conventional denture for the mandibular arch and a removable partial denture for the maxillary arch were fabricated. A correct occlusal adjustment and a satisfactory amount of alveolar bone was favorable for conventional dentures of the prostheses bases improve their retention and stability. After one year of follow-up, the patient was adapted to the prostheses, satisfied with their retention, and reported an improvement on his feeding. Discussion The prosthetic rehabilitation of patients after a partial mandibulectomy is essential for their self-steam. Conventional dentures may have their retention and stability improved if they are well fabricated, recorded and have a balanced occlusion. Conclusion A correct occlusal adjustment and an adequate retention of the prostheses bases may improve their retention and stability. Patients without xerostomy and with a satisfactory amount of alveolar bone may have a favorable prognosis for conventional dentures. PMID:26052437

  15. Prosthetic rehabilitation of a patient after a partial mandibulectomy.

    PubMed

    Goiato, Marcelo Coelho; de Medeiros, Rodrigo Antonio; Vechiato Filho, Aljomar José; da Silva, Emily Vivianne Freitas; Sônego, Mariana Vilela; de Carvalho, Karina Helga Turcio; Guiotti, Aimée Maria; de Carvalho Dekon, Stefan Fiuza; Pesqueira, Aldiéris Alves; Dos Santos, Daniela Micheline

    2015-06-01

    The treatment of orofacial tumors may cause facial deformities by losses of structures that affect basic functions, i.e. feeding, speech, and the reduction of patient self-steam. A white male patient was diagnosed with epidermoid cancer on the mandibular alveolar ridge with infiltration staging IV A. The patient was submitted to a mandibulectomy associated with a complete extraction of mandibular teeth. For rehabilitation, a conventional denture for the mandibular arch and a removable partial denture for the maxillary arch were fabricated. A correct occlusal adjustment and a satisfactory amount of alveolar bone was favorable for conventional dentures of the prostheses bases improve their retention and stability. After one year of follow-up, the patient was adapted to the prostheses, satisfied with their retention, and reported an improvement on his feeding. The prosthetic rehabilitation of patients after a partial mandibulectomy is essential for their self-steam. Conventional dentures may have their retention and stability improved if they are well fabricated, recorded and have a balanced occlusion. A correct occlusal adjustment and an adequate retention of the prostheses bases may improve their retention and stability. Patients without xerostomy and with a satisfactory amount of alveolar bone may have a favorable prognosis for conventional dentures.

  16. [Mechanism of nitrogen removal by partial nitrification-denitrification biological filter].

    PubMed

    Sun, Ying-Xue; Xu, Dong; Tian, Yuan; Li, Yan-Fei

    2012-10-01

    The controlling factors for nitrite accumulation in partial nitrification and mechanism of nitrogen removal from the secondary effluent of wastewater treatment plant by partial nitrification-denitrification biological filter were investigated. The results showed that nitrite accumulated with increasing of pH value in the influent under the condition of temperature was (30 +/- 1) degrees C. The nitrite accumulation achieved to the highest at a pH value of 8.5 in this batch experiments. In addition, the nitrite accumulation presented increasing tendency through the up-flow nitrifying biological filter, which can be adjusted by the changes of pH and DO through the filter. The removal efficiency of NH4+ -N was over 90% by the partial nitrification-denitrification biological filter. Meanwhile, carbon sources were supplied for the denitrifying bacteria to accomplish denitrification process. Under the condition of COD/TN at a value of 3.0, the concentration of TN in the effluent of denitrifying biofilter was 8-9 mg x L(-1) and the removal efficiency achieved 79% - 81%, stably.

  17. Development of a Contemporary Animal Model of Candida albicans-Associated Denture Stomatitis Using a Novel Intraoral Denture System

    PubMed Central

    Johnson, Clorinda C.; Yu, Alika; Lee, Heeje; Fidel, Paul L.

    2012-01-01

    Denture stomatitis (DS) is a fungal infection characterized by inflammation of the oral mucosa in direct contact with the denture and affects up to 50% of denture wearers. Despite the prevalence, very little is known about the role of fungal or host factors that contribute to pathogenesis. Recently, we developed a novel intraoral denture system for rodent research. This denture system consists of custom-fitted fixed and removable parts to allow repeated sampling and longitudinal studies. The purpose of this study was to use this denture system to develop a clinically relevant animal model of DS. To establish DS, rats were inoculated with pelleted Candida albicans, which resulted in sustained colonization of the denture and palate for 8 weeks postinoculation. Biofilm formation on the denture was observed by week 4 and on the palate by week 6 postinoculation. Rats were monitored for clinical signs of disease by assigning a clinical score after macroscopic examination of the palate tissue according to Newton's method. By week 4 postinoculation, the majority of inoculated rats with dentures exhibited a clinical score of 1 (pinpoint erythema). By week 6 and week 8 postinoculation, increasing percentages of rats exhibited a clinical score of 2 (diffuse erythema/edema). Histological analysis of palate tissue demonstrated progressively increasing inflammatory cell recruitment throughout the time course of the infection. Palatal biofilm formation was commensurate with development of palatal erythema, which suggests a role for biofilm in the inflammatory response. PMID:22392931

  18. Denture Care: How Do I Clean Dentures?

    MedlinePlus

    ... are a few things you typically should avoid: Abrasive cleaning materials. Avoid stiff-bristled brushes, strong cleansers and harsh toothpaste, as these are too abrasive and can damage your dentures. Whitening toothpastes. Toothpastes ...

  19. Complete-denture esthetics.

    PubMed

    Engelmeier, R L

    1996-01-01

    This review of complete denture esthetics addresses the process of tooth selection, tooth arrangement, and characterization of the denture bases. The guidelines discussed in this article are all gleaned from the classic prosthodontic literature. These principles, which were developed over the past century, coupled with state-of-the-art materials are artificial teeth enable contemporary dentists to fabricate complete dentures with a level of esthetics never before possible.

  20. Treatment of deep carious lesions by complete excavation or partial removal

    PubMed Central

    Thompson, Van; Craig, Ronald G.; Curro, Fredrick A.; Green, William S.; Ship, Jonathan A.

    2009-01-01

    Background The classical approach to treatment of deep carious lesions approaching the pulp mandates removing all infected and affected dentin. Several studies call this approach into question. Types of Studies Reviewed A search of five electronic databases using selected key words to identify studies relating to partial versus complete removal of carious lesions yielded 1,059 reports, of which the authors judged 23 to be relevant. Three articles reported the results of randomized controlled trials. Results The results of three randomized controlled trials, one of which followed up patients for 10 years, provide strong evidence for the advisability of leaving behind infected dentin, the removal of which would put the pulp at risk of exposure. Several additional studies have demonstrated that cariogenic bacteria, once isolated from their source of nutrition by a restoration of sufficient integrity, either die or remain dormant and thus pose no risk to the health of the dentition. PMID:18519994

  1. Trial of an experimental castor oil solution for cleaning dentures.

    PubMed

    Andrade, Ingrid Machado de; Andrade, Kelly Machado de; Pisani, Marina Xavier; Silva-Lovato, Cláudia Helena; de Souza, Raphael Freitas; Paranhos, Helena de Freitas Oliveira

    2014-01-01

    Denture hygiene is essential because denture biofilm is involved in oral infections and systemic diseases. Although there are chemical agents available on the market, none of them have ideal properties and research on such products is still necessary. The aim of this study was to evaluate the efficacy of a castor bean (Ricinus communis)-based solution for removing denture biofilm, compared to two traditional products (sodium hypochlorite and alkaline peroxide). Fifty maxillary complete denture wearers were instructed to brush their dentures after meals and to immerse their dentures once a day in the following solutions: Saline (20 min; control), Polident alkaline peroxide (3 min), NaOCl (20 min) and 2% castor oil solution (20 min). Participants used each solution for a period of 7 consecutive days, according to a random sequence. After each period, the internal surfaces of maxillary complete dentures were stained with a disclosing solution (1% neutral red), photographed and the disclosed biofilm was quantified with the aid of specific software. The influence of treatments on results was verified by the Friedman test (α=0.05). Tested solutions presented significant difference (Fr=51.67; p<0.001). Saline and NaOCl were significantly different (median: 2.0% and 0.0%) whereas Polident and castor oil presented intermediate results (median: 1.0% and 1.5%, respectively). It can be concluded that the castor oil solution tested in this study was comparable to alkaline peroxide in terms of efficiency in denture biofilm removal.

  2. Occurrence rate of oral Candida albicans in denture wearer patients.

    PubMed

    Daniluk, T; Tokajuk, G; Stokowska, W; Fiedoruk, K; Sciepuk, M; Zaremba, M L; Rozkiewicz, D; Cylwik-Rokicka, D; Kedra, B A; Anielska, I; Górska, M; Kedra, B R

    2006-01-01

    The aim was to determine the fungi occurrence rate in the oral cavity of denture wearer patients in comparison to those without dentures. The examinations were conducted in patients treated in two clinical departments of the University Hospital. Demographic data and those connected with basic diseases were collected and the evaluation concerning dentition and oral hygiene was performed. Samples for mycological examinations from the tongue dorsa, palatal mucosa, and mucosal surfaces of dentures were collected from patients with dentures while tongue and palate swabs were taken from those without dentures. For culture and identify of fungi standard methods were used. Dental and mycological examinations were performed in 95 patients, out of which 57 (60.0%) used complete or partial dentures and 38 (40.0%) had their own dentition (without dentures). Oral cavity revealed only growth of Candida albicans species, more frequently in patients with dentures (38/57; 66.7%) than in those without dentures (11/ 38; 28.9%) (p = 0.0003). C. albicans statistically significantly more frequently was isolated in denture wearer patients with diabetes mellitus (p = 0.0207) and without diabetes (p = 0.0376) comparing to such groups of patients but without dentures. Among 32 patients with diabetes mellitus, 14 (43.8%) revealed C. albicans; this rate was comparable with 9/23 (39.1%) patients without diabetes (p > 0.05). A similar analysis, conducted in 25 surgical patients with abdominal cancer and 15--without--cancers, did not show statistically significant differences in the incidence rate of C. albicans; it also concerned denture wearers (14/16; 87.5%) and non-wearing dentures (5/9; 55.6%) (p > 0.05) with cancer. In 37 (64.9%) wearer patients denture stomatitis was observed, associated mainly with C. albicans infections (29/37; 78.4%). 1) Mycological findings from the present study do not indicate that diabetes mellitus or advanced cancer has a significant effect on oral colonisation by

  3. Alternative splicing tends to avoid partial removals of protein-protein interaction sites

    PubMed Central

    2013-01-01

    Background Anecdotal evidence of the involvement of alternative splicing (AS) in the regulation of protein-protein interactions has been reported by several studies. AS events have been shown to significantly occur in regions where a protein interaction domain or a short linear motif is present. Several AS variants show partial or complete loss of interface residues, suggesting that AS can play a major role in the interaction regulation by selectively targeting the protein binding sites. In the present study we performed a statistical analysis of the alternative splicing of a non-redundant dataset of human protein-protein interfaces known at molecular level to determine the importance of this way of modulation of protein-protein interactions through AS. Results Using a Cochran-Mantel-Haenszel chi-square test we demonstrated that the alternative splicing-mediated partial removal of both heterodimeric and homodimeric binding sites occurs at lower fr