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Quantification of oxidative metabolism in masseter muscle of denture wearers  

Microsoft Academic Search

This study aimed to quantify oxidative metabolism in masseter muscle using near-infrared spectroscopy, in particular for denture wearers. Fourteen normal dentate subjects without malocclusion (ND group, 25–50 years) participated in the quantification of oxidative metabolism. Eleven partially edentulous patients without occlusal stops (PD group, 64–80 years) and ten edentulous patients (CD group, 57–84 years) also participated after prosthodontic treatment. Oxidative

A. Fujii; T. Shinogaya; S. Toda; I. Hayakawa



Joint sounds in complete denture wearers. Literature review.  


Long-term denture wearers can present with prosthesis instability, reduced occlusal vertical dimension and incorrect positioning of the jaw. This can lead to muscular changes and joint vibration. This study presents the main considerations related to joint vibrations in partially or totally edentulous patients. Occlusal treatment improves the disc-condyle relationship in the mandibular fossa. Furthermore, a detailed clinical exam and anamnesis must be performed to identify the dysfunction and its etiology, so that appropriate treatment can be provided. PMID:20359066

Goiato, Marcelo Coelho; dos Santos, Daniela Micheline; Monteiro, Douglas Roberto



Partial Denture Alloy-Denture Cleanser Interaction.  

National Technical Information Service (NTIS)

The electrochemical behavior of three partial denture casting alloys was studied. Under simulated conditions of denture storage, only one test alloy exhibited spontaneous active-passive transition. The findings contraindicate the use of five widely used m...

E. F. Huget S. G. Vermilyea F. A. Modawar



A simple technique for increasing the occlusal vertical dimension of removable denture wearers.  


This article describes a simple and efficient technique for increasing the occlusal vertical dimension of removable denture wearers. Functionally generated path technique is carried out by using gothic arch tracing, and the existing mandibular overdenture is modified for interim use. PMID:22409139

Sulun, Tonguc; Geckili, Onur



Designing successful removable partial dentures.  


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. PMID:16553007

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



21 CFR 872.3600 - Partially fabricated denture kit.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Partially fabricated denture kit. 872.3600 Section 872.3600 Food...872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated denture kit is a device composed of...



Partial denture-- an ENT surgeon's nightmare.  


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. PMID:23785926

Venugopal, M; Sagesh, M



[Six channels telemetry system for recording masticatory forces of complete denture wearers].  


A six channels telemetry system for recording masticatory force of complete denture wearers has been developed. This system is consisted of three blocks, the transmission block, the receiver block and the data storage and correction block. The transmission block is embedded in a lower complete denture. System has six load sensors and a standard resistor to correct sensor data. Data from six load sensors and standard resistor as well as standard zero are multiplexed using a division multiplex communication method. The sampling frequency is 666 Hz. And the signal is transmitted by FM modulation. The carrier wave frequency is 64 MHz. Receive data are decoded using start-stop system. The wave form noise is reduced using a signal averaging technique at an integrator. The data are input into the computer with an A/D converter. In this system, the sensor data is corrected at the computer with the standard resistor data. This method could reduce the influence of battery power changes and thermal drift significantly. For the load of 10 kg or less, the total linearity of the system remained at +/- 4% of the calibrated value. The noise level is 300 g. PMID:2810879

Watanabe, T; Kobayashi, K; Nagao, M



[Resin-bonded fixed partial dentures].  


A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed partial denture is occlusally supported by the abutment(s). A direct resin-bonded fixed partial denture is made of composite, reinforced or not by a frame of flexible metal or fiber material. For an indirect resin-bonded fixed partial denture, a metal, fibre-reinforced composite or ceramic substructure is fabricated in a dental laboratory. The basic principle of a resin-bonded fixed partial denture is minimal invasiveness. However, a restoration in an abutment tooth requires a certain occlusal space which is realized by tooth preparation. Resistance preparations may be performed to improve the longevity of resin-bonded fixed partial dentures. Both financially and biologically, a resin-bonded bridge is a cost-effective prosthetic construction. The longevity is limited, but when the construction fails the negative consequences for the abutments are generally limited, which leaves open several types of other treatments. PMID:23495569

Kreulen, C M; Creugers, N H J



[Elderly people and removable partial dentures].  


The most frequently reported disadvantages of removable partial dentures are the more demanding daily oral hygiene self-care, especially for people who already experience difficulties in self-care, and the possible harmful influence on the remaining dentition. These disadvantages can be expressed in an extreme form in (frail) elderly people. The elderly show relatively large amounts of oral plaque, (root) caries, and periodontal disease. Considerations which may or may not indicate a partial denture for a (frail) elderly person are: the expressed problem and demand for treatment, the general health condition ofthe patient, oral mucosal health, the condition of the opposing jaw, the possible contribution to function and/or aesthetics, the possibilities of oral self-care and/or volunteer aid, the patient's personal adaptability, and possible hazards. Extreme care in subsequent, decisions should be the rule. Key concepts are: explicit demand for treatment, appropriateness, safety, and oral self-care/volunteer aid. PMID:20101935

de Baat, C



Molecular typing of Candida albicans strains isolated from denture wearers by repetitive sequence-based PCR  

Microsoft Academic Search

Long-term use of prosthesis is the most important risk factor for the colonization of Candida species on the mucosal surfaces, which can lead to the development of denture-related stomatitis (DRS). Some individuals\\u000a wearing prosthesis develop DRS and others do not. C. albicans strains isolated from both groups were genotypically compared. The purpose of this study was to determine whether the

O. Abaci; A. Haliki-Uztan; B. Ozturk; S. Toksavul; M. Ulusoy; H. Boyacioglu



Implants in conjunction with removable partial dentures: a literature review.  


Although the benefits of implant-borne removable prostheses are readily apparent for the fully edentulous patient and have been well documented, there is a paucity of studies concerning the combination of implants with removable partial dentures in partially edentulous patients. The aim of this article is to review the literature regarding implants with removable partial dentures and evaluate the evidence for this clinical approach. A MEDLINE/PubMed search from 1990 to 2006, focusing on the use of implants with removable partial dentures and related features, was supplemented with a hand search to identify relevant peer-reviewed English articles published in dental journals and textbooks on removable partial dentures. PMID:17563505

Mijiritsky, Eitan



Geriatric slim implants for complete denture wearers: clinical aspects and perspectives  

PubMed Central

Background Advances made in prevention have helped postpone complete edentulism in older patients. However, in the elderly, the physiological state reduces patients’ ability to adapt to oral rehabilitation and degrades the patient’s oral condition. Consequently, elderly edentulous subjects avoid many types of foods, which can lead to substantial nutritional consequences. Complete dentures retained by implants are, currently, the treatment of reference in prosthodontic mandibular rehabilitation. Indeed, the mandibular symphysis generally tolerates implantation, even when the mandible is strongly resorbed. However, in the elderly, implant rehabilitation is compromised by the complexity of the surgical protocol and possible postoperative complications. In this context, the use of geriatric “slim implants” (GSI) offers an interesting alternative. Methods In the present study, the surgical and prosthetic procedures for the use of GSI in a French dental hospital are presented. The objective was the stabilization of a complete mandibular denture in an elderly person, with the immediate implantation of four GSI. Results The operating procedure was found to be less invasive, less expensive, simpler, and more efficient than the conventional procedure. Conclusion The result strongly suggests that this protocol could be used systematically to treat complete edentulism in very elderly patients. Long-term monitoring and the evaluation of the reliability of this type of rehabilitation should be undertaken.

Huard, Cedric; Bessadet, Marion; Nicolas, Emmanuel; Veyrune, Jean-Luc



Fabricating an interim immediate partial denture in one appointment (modified jiffy denture). A clinical report.  


An immediate denture is fabricated before all the remaining teeth have been removed. Its advantages include maintenance of a patient's appearance, muscle tone, facial height, tongue size, and normal speech and reduction of postoperative pain. The purpose of this study is to describe the use of a patient's fixed prosthesis for fabricating an interim immediate partial denture in one appointment. Occlusion, occlusal vertical dimension, and facial support are maintained during the healing period in this procedure. PMID:23279141

Gooya, Ali; Ejlali, Massod; Adli, Amin Rezayi



Casting titanium partial denture frameworks: A radiographic evaluation  

Microsoft Academic Search

Statement of Problem. Titanium is the most biocompatible metal available for dental castings. However, there is some concern about the castability of titanium used on a daily basis. Purpose. A radiographic evaluation of titanium partial denture frameworks was undertaken to ascertain whether these castings were technically acceptable for clinical use. Material and Methods. Three hundred Grade II titanium removable partial

Bert T. Cecconi; Raymond G. Koeppen; Rodney D. Phoenix; Mark L. Cecconi



Prefabricated light-polymerizing plastic pattern for partial denture framework  

PubMed Central

Our aim is to report an application of a prefabricated light-polymerizing plastic pattern to construction of removable partial denture framework without the use of a refractory cast. A plastic pattern for the lingual bar was adapted on the master cast of a mandibular Kennedy class I partially edentulous patient. The pattern was polymerized in a light chamber. Cobalt–chromium wires were employed to minimize the potential distortion of the plastic framework. The framework was carefully removed from the master cast and invested with phosphate-bonded investment for the subsequent casting procedures. A retentive clasp was constructed using 19-gauge wrought wire and was welded to the framework by means of laser welding machine. An excellent fit of the framework in the patient's mouth was observed in the try-in and the insertion of the denture. The result suggests that this method minimizes laboratory cost and time for partial denture construction.

Takaichi, Atsushi; Wakabayashi, Noriyuki; Igarashi, Yoshimasa



Fracture surface analysis of clinically failed fixed partial dentures.  


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. PMID:16498078

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



Fracture Surface Analysis of Clinically Failed Fixed Partial Dentures  

PubMed Central

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.

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



Biomechanical considerations on tooth-implant supported fixed partial dentures  

PubMed Central

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.

Calvani, Pasquale; Hirayama, Hiroshi



Research SummaryPressed ceramic in fixed partial dentures construction  

Microsoft Academic Search

Purpose This study compares the marginal accuracy of posterior metal ceramic (MC), all-ceramic IPS Empress®2 and experimental pressed ceramic (EPC-VP 1989\\/4) three-unit fixed partial dentures (FPD), before and after luting and after thermo-mechanical fatigue in a dual-axis chewing simulator.Materials and methods Caries-free human teeth (n=160) were used as abutments for the fabrication of eighty posterior three-unit FPD, divided into two

R Van Noort



Simplified technique for the removal of a fixed partial denture.  


A simplified method of removing a fixed partial denture has been described. The principle of the Class I or II lever systems is used to deliver force along the path of withdrawal. Carefully applied, this technique may permit removal of a restoration with minimal trauma to the prosthesis and supporting teeth. Where reasonable pressure fails to dislodge the restoration, it should be sacrificed rather than risk permanent damage to the abutment. PMID:7028968

Conny, D J; Brown, M H



Can new dentures decrease Candida levels?  


Purpose: The aim of this study was to evaluate the influence of time-course changes and various types of removable dentures on the oral levels of Candida species. Materials and Methods: In this prospective clinical trial, 72 subjects were divided into three groups according to the type of denture replaced: Kennedy Class I or II removable partial dentures (RPDs), Kennedy Class III or IV RPDs, and complete dentures. Whole saliva and biofilm samples from the palate, tongue, dentures, and inner surface of the cheek were obtained and evaluated for Candida diversity before the delivery of the new prostheses (baseline) and at 1, 6, and 12 months postdelivery. The results were analyzed using a three-way analysis of variance, followed by a post hoc Student-Newman-Keuls test. Results: Candida levels decreased after the insertion of the new dentures; however, after 6 months, Candida levels were similar to baseline, and complete denture wearers presented higher Candida counts than RPD wearers. Conclusion: The type of denture does not seem to be a decisive factor in Candida levels. After 6 months, Candida colonization was well established in all types of removable prostheses. Denture replacement alone did not guarantee a decrease in Candida levels for more than 6 months. PMID:23998146

Pereira-Cenci, Tatiana; Fernandes, Frederico S F; Skupien, Jovito A; Mesko, Mauro E; Straioto, Fabiana G; Del Bel Cury, Atair A


Rotational Path Concept in Removable Partial Denture Design--A Series.  

National Technical Information Service (NTIS)

Describes the use of the rotational path in insertion and designing removable partial dentures for maxillary class iv partially edentulous arches. Also describes the uses of the rotational path concept in the maxillary and mandibular class 111 bilateral p...



Incorporation of a cast, embossed identification plate into a partial denture framework.  


This article presents a technique for the fabrication and incorporation of a stable and fireproof identification plate into a cast partial denture framework. Embossing tape is embedded in the wax pattern of the major connector. The resulting casting reproduces the embossed lettering, which is identifiable through the tissue-colored acrylic denture base resin. PMID:12397250

Matsumura, Hideo; Shimoe, Saiji



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


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. PMID:20415245

Tsuchiya, Kyoko



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

PubMed Central

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.

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



Mechanical considerations for the implant tooth-supported fixed partial denture.  


The implant tooth-supported fixed partial denture presents a biomechanical design problem, because the implant is rigidly fixed within the alveolus, and the tooth is surrounded by a periodontal ligament that allows movement. Nonrigid fixed partial denture designs are advocated by some dentists as a method of compensating for this differential movement. Rigid fixed partial denture designs, however, are advocated by many clinicians. Studies have failed to show the advantage of one design over the other. This study developed an in vitro method for testing such prosthesis designs and measured movement of a natural tooth abutment during simulated function. The movement of the natural tooth abutment was not found to change substantially with the fixed partial denture designs tested. PMID:8809254

Breeding, L C; Dixon, D L; Sadler, J P; McKay, M L



Single tooth replacement using a ceramic resin bonded fixed partial denture: A case report  

PubMed Central

This article describes the use of an all ceramic resin-bonded fixed partial denture as a conservative solution for the replacement of an incisor. It is a minimally invasive technique that does not discolor the abutment teeth.

Kara, Haluk Baris; Aykent, Filiz



Strength of zirconia fixed partial dentures: review of the literature  

PubMed Central

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.




Comparison of Effects of Bleach and Cleansing Tablet on Reflectance and Surface Changes of a Dental Alloy Used for Removable Partial Dentures  

Microsoft Academic Search

Proper hygienic care of removable partial dentures is important for maintaining a healthy oral mucosa. A daily home care routine is the responsibility of the patient to maintain oral hygiene. A dentist must inform the patient about denture cleansers used for plaque control. Common denture cleansers may negatively affect the surface of alloys used to make partial dentures. The purpose

Tayyar Güngör



Marginal Integrity of CAD/CAM Fixed Partial Dentures  

PubMed Central

Objectives Computer-aided design (CAD) and manufacturing (CAM) allows the milling of high strength zirconia fixed partial dentures (FPD), however bonding to an inert ZrO2 ceramic surface may effect the marginal integrity of the FPDs. The aim of this investigation was to evaluate the marginal adaptation of zirconia FPDs at the interfaces between zirconia, cement, and tooth. Methods 32 3-unit FPDs were fabricated of the CAD/CAM Y-TZP zirconia (Lava, 3M Espe, Germany) according to the manufacturers’ instructions. Resin cements with corresponding primer and bonding systems were used to lute the FPDs: Compolute/EBS multi (3M Espe, Germany), Panavia F/ED (Kuraray, Japan), Variolink 2/Syntac classic (Ivoclar-Vivadent, FL) and RelyX Unicem/without treatment (3M Espe, Germany). Aualloy FPDs (BioPontostar, Bego, Germany) were cemented with RelyX Unicem and Harvard (Harvard, Germany) as the control. Marginal adaptation was evaluated with scanning electron microscopy using replica specimen before and after artificial aging. After aging, microleakage tests were performed with fuchsine solution. The interfaces between cement-tooth and cement-FPD were examined. Results At the interfaces (cement-tooth and cement-FPD), the systems showed a 95% or higher perfect margin before and after aging. Only Variolink2/Syntac had a marginal adaptation, lower than a 70% perfect margin. Generally, the fuchsine penetration was below 20%, only BioPontstar/Harvard andLava/Variolink2 showed penetration results between 80% and 100%. Conclusion The success of the adhesive cementation of zirconia FPDs depends on the cement system. Under the conditions of this study, zirconia FPDs showed good to sufficient marginal integrity in combination with Panavia/ED, Compolute/EBS and RelyX Unicem.

Rosentritt, Martin; Behr, Michael; Kolbeck, Carola; Handel, Gerhard



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

Microsoft Academic Search

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

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



Stiffness of different designs and cross-sections of maxillary and mandibular major connectors of removable partial dentures  

Microsoft Academic Search

Statement of problem. Major connectors of removable partial dentures must distribute forces bilaterally without damaging the supporting tissues. Purpose. This study investigated which design and cross-sectional shape of major connectors most favorably influence rigidity and flexibility. Methods and material. Five designs for maxillary removable partial denture major connectors and 5 lingual bar major connectors of different cross-sectional forms were cast

Zeev Ben-Ur; Eitan Mijiritsky; Colin Gorfil; Tamar Brosh



Reestablishment of occlusion through overlay removable partial dentures: a case report.  


Loss of posterior teeth may cause an imbalance in the stomatognathic system. Overlay removable partial dentures (ORPD) are a reversible and relatively inexpensive treatment for patients with severely worn teeth. This paper presents a treatment with ORPD in a 55-year-old male patient who had severe attrition in the maxillary and mandibular teeth, temporomandibular joint pain and reduced vertical dimension of occlusion (VDO). The treatment consisted in the reestablishment of the VDO using Lucia's jig, fabricating removable partial denture with reconstruction of the worn teeth without preparation. This therapy can be used as an alternative treatment to provide esthetic, function and stable occlusion in patients with severely worn teeth. PMID:22666777

Bataglion, César; Hotta, Takami Hirono; Matsumoto, Wilson; Ruellas, Carlos Ventura de Oliveira



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


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. PMID:19119547

Bär, C; Reich, S



[Oral candidiasis and dentures].  


Yeasts belonging to the Candida genus usually colonize the human oral cavity. Immunocompromised patients or individuals with an imbalance of their oral microflora can develop yeast infections from this reservoir. However, saliva protects oral mucosa against candidosis; in turn, dry mouth is associated with increased yeast counts and candidosis risk. In vivo and in vitro studies have shown Candida incorporation into biofilms covering different biomaterials such as dentures: these biofilms may be an increased risk factor for invasive candidosis when the host immune system is compromised. Daily denture brushing is recommended to all wearers. Family or healthcare workers must take over this task when there is autonomy loss, especially in the elderly. In case of candidosis in denture wearers, decontamination of dentures is mandatory. Antimycotics (azoles, nystatin) must be kept for curative treatments of infected patients; they are less active against Candida biofilms on dentures and could lead to emergent resistance if applied daily to dentures against yeast colonization. There are several antiphlogistic solutions with antifungal properties. Nevertheless, literature data does not integrate all aspects of denture care: welfare of denture wearers, prevention of candidosis, biomaterial defects after decontamination processing, and taking into account possible Candida biofilm development. Daily brushing of dentures remains the key recommendation. PMID:20347465

Ahariz, M; Loeb, I; Courtois, P



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

PubMed Central

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.

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



Comparative study of circumferential clasp retention force for titanium and cobalt-chromium removable partial dentures  

Microsoft Academic Search

Statement of Problem. The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies to support its use. Purpose. The objective of this study was to compare circumferential RPD clasps made of commercially pure titanium and identical clasps made of 2 different cobalt (Co)-chromium (Cr) alloys by testing insertion\\/removal and radiographically inspecting

Renata Cristina Silveira Rodrigues; Ricardo Faria Ribeiro; Maria da Gloria Chiarello de Mattos; Osvaldo Luiz Bezzon



Comparison of titanium and cobalt-chromium removable partial denture clasps  

Microsoft Academic Search

Statement of problem. The use of titanium alloys for removable partial dentures is an increasingly popular application. While the flexibility of titanium would allow for cast clasps to be placed in deeper undercuts than advisable with cobalt-chromium, it is possible that the retentive forces of the titanium clasp might not maintain sufficient retention after repeated flexing of the clasp arm

Jay T. Bridgeman; Victoria A. Marker; Susan K. Hummel; Byron W. Benson; Larry L. Pace



Numerical simulation of the casting process of titanium removable partial denture frameworks  

Microsoft Academic Search

The objective of this work was to study the filling incompleteness and porosity defects in titanium removal partial denture frameworks by means of numerical simulation. Two frameworks, one for lower jaw and one for upper jaw, were chosen according to dentists’ recommendation to be simulated. Geometry of the frameworks were laser-digitized and converted into a simulation software (MAGMASOFT). Both mold

Menghuai Wu; Ingo Wagner; Peter R. Sahm; Michael Augthun



Treatment outcomes with mandibular removable partial dentures: A population-based study of patient satisfaction  

Microsoft Academic Search

Statement of problem. Little is known about the outcomes of treatment with mandibular removable partial dentures provided by dentists in private dental practice.Purpose. This study examined 15 aspects of patient satisfaction and explored the factors found to be associated with dissatisfaction.Material and methods. A questionnaire was mailed to people whose dental insurance claims included CPT Code 5214 within the last

Richard P. Frank; Peter Milgrom; Brian G. Leroux; Natalie R. Hawkins



Unstable cracking (chipping) of veneering porcelain on all-ceramic dental crowns and fixed partial dentures  

Microsoft Academic Search

The central argument of this study is that residual stresses developed during the preparation of all-ceramic crowns and fixed partial dentures coupled with contact-induced cracking are the origin of the excessive chipping observed in clinical applications. The aim of this paper is to provide a simple basic analysis of the causes of residual stress development in ceramics and identify the

M. V. Swain



Why do dentists struggle with removable partial denture design? An assessment of financial and educational issues  

Microsoft Academic Search

Aim Published studies in the international dental literature illustrate that the quality of prescription and fabrication of cobalt-chromium removable partial dentures (CCRPDs) by general dental practitioners frequently fail to comply with ethical and legal requirements. The reasons cited for this in the past have broadly related to either financial or educational issues. The aim of this investigation is to determine

P F Allen; C D Lynch



Future needs for fixed and removable partial dentures in the United States  

Microsoft Academic Search

Statement of Problem. Because of the decline in missing teeth among most adults, prosthodontic advanced training programs are concerned about the need for prosthodontics in the future. Purpose. An analysis was conducted to project the unmet need for fixed and removable partial dentures in the years 2005, 2010, and 2020. Material and Methods. Unmet need was calculated as follows: Total

Chester W. Douglass; Ascella J. Watson



Fracture strength of all-ceramic posterior inlay-retained fixed partial dentures  

Microsoft Academic Search

ObjectivesThe purpose of this in vitro study was to compare the quasi-static (QSFS) and fatigue fracture strength of all-ceramic resin-bonded three unit inlay-retained fixed partial dentures (IRFPDs) made from a heat-pressed lithium-disilicate based glass-ceramic (LDGC) and a CAD\\/CAM-manufactured yttrium-oxide partially stabilized zirconia framework (YPSZ).

Stefan Wolfart; Klaus Ludwig; Anja Uphaus; Matthias Kern



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

PubMed Central

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.

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



Use of dental implants to improve unfavorable removable partial denture design.  


This study aimed to determine whether the use of a limited number of dental implants, with no rigid connection between implants and teeth and as few as possible prosthetic element requirements, is a viable solution for improving unfavorable removable partial dentures (RPD) design. Fifteen partially edentulous patients with an unfavorable number and distribution of abutment teeth were treated, each with a limited number of implants, from 1997 to 2004, resulting in an improved RPD design. Implant survival rate was 100%, and prosthetic complications were minor. All patients reported great satisfaction with the partial dentures and good chewing efficiency. The results indicate that the use of dental implants to improve unfavorable RPD design is a viable and cost-effective treatment modality. PMID:16231543

Mijiritsky, Eitan; Ormianer, Zeev; Klinger, Avigdor; Mardinger, Ofer



A review of 243 errors possible during the fabrication of a removable partial denture: part I.  


Everyone who participates in any step of the fabrication of a removable partial denture must share in the success or failure of the restoration. Some seemingly innocuous deviations can be accumulative and cause serious problems, so everyone should review the procedures that they use on a regular basis. Parts I through III of this article present a personal and generic (but by no means comprehensive) list of errors that can occur when a removable partial denture is fabricated. Results that can be attributed to these errors are identified, and a possible solution for each error is described. This information is useful to the entire dental team: the dentist, dental assistant, office manager, and dental technician. The articles also include 18 notes that may be beneficial to personnel in the office and/or in the laboratory. PMID:11552163

Rudd, R W; Rudd, K D



Marginal adaptation of three-unit fixed partial dentures constructed from pressed ceramic systems  

Microsoft Academic Search

Purpose This study compares the marginal accuracy of posterior metal ceramic (MC), all-ceramic IPS Empress®2 and experimental pressed ceramic (EPC-VP 1989\\/4) three-unit fixed partial dentures (FPD), before and after luting and after thermo-mechanical fatigue in a dual-axis chewing simulator.Materials and methods Caries-free human teeth (n=160) were used as abutments for the fabrication of eighty posterior three-unit FPD, divided into two

M Dai; S Chitmongkolsuk; T Gerds; J R Strub; C F J Stappert



The computer-aided design and rapid prototyping fabrication of removable partial denture framework  

Microsoft Academic Search

This paper investigated the feasibility to design and fabricate a sacrificial pattern for a removable partial denture (RPD) metal alloy framework with computer-aided design (CAD) and rapid prototyping (RP) technologies. A plaster cast of a patient was digitally scanned with an optical scanner and the captured surface data were imported to three-dimensional (3-D) softwares, which were then used to preprocess

Yan Guo-Dong; Liao Wen-He; Dai Ning; Yang Leilei; Gao Yi-Guo; Zhu Shen-Yang; Cai Yu-Hui



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


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

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



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

PubMed Central

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.

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



Preparing fixed partial denture abutments such that they provide a path of placement free of undercuts.  


The abutments of a fixed partial denture (FPD) should provide a path of placement, so that the denture may be seated onto the abutment without tooth structure blocking the margin or intaglio surface. This article presents a literature review concerning the path of placement (also referred to as the path of insertion or the path of draw). In addition, the article presents clinical techniques for verifying an undercut-free path of placement for a prepared abutment and describes how to determine if a laboratory technician can fabricate a clinically acceptable FPD for an abutment that features undercuts within the path of placement. The article provides definitions of terms such as "path of placement" and "undercut" and explains concepts such as "parallelism of multi-unit fixed partial denture abutments" and also what a dentist means when the dentist says that an abutment "is undercut." The author suggests that dentists use high magnification loupes (6-8X magnification or greater) or a surgical operating microscope to examine abutments for microscopic undercuts and to ensure that bridge abutments are aligned with a path of placement. PMID:23220307

Mamoun, John


Clinical evaluation of fixed partial dentures made in Sweden and China.  


The aim of this study was to compare the quality of fixed partial dentures (FPDs) made in a Chinese dental laboratory with corresponding FPDs made in Swedish dental laboratories. Twenty-one patients were fitted with FPDs between March 2007 and December 2008. Single crowns and prostheses of up to seven units were made. All dentures, gold and CoCr alloys covered with ceramic, were produced in duplicate: one by a dental technician in China and the other by a dental technician in Sweden. The dentures were blind-tested with regard to marginal integrity, anatomic form and color, approximal and occlusal contacts, and time taken for adjustments. The composition of dentures was analyzed, and the material used, framework weight, compliance of the laboratories, and costs (material and labour) were recorded. There was no difference in the quality of marginal integrity, anatomic form, color, approximal and occlusal contacts, or in the time taken for adjustments. The bridge frameworks made in China were thinner and lighter (p<0.01) than those made in Sweden. Three FPDs from China showed elastic deformation when tested clinically and were considered too thin for clinical use. In 11 out of 14 orders from the Chinese laboratory, the gold alloy specified was not delivered and the cobalt-chromium alloy contained small amounts (0.19%) of nickel.The prostheses with gold-alloy frameworks from China cost 47% of those from Sweden (p<0.01) and those with cobalt/chromium frameworks 44% (p<0.01). In conclusion, the quality of the FPDs made in Sweden and China was comparable, with the exception of the dimension of the Chinese bridges, which in some cases was considered too weak. The gold alloy ordered from the Chinese laboratory was often not the alloy delivered and the CoCr alloy contained small amounts of nickel. FPDs from China cost less than half the price of those from Sweden. PMID:22135942

Ekblom, Karin; Smedberg, Jan-Ivan; Moberg, Lars-Erik



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


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. PMID:15747188

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



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

PubMed Central

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.

Ozdemir, Eylem



Multivariate analysis of patient satisfaction factors affecting the usage of removable partial dentures.  


The purpose of this retrospective cohort study was to investigate patient satisfaction factors that affect the usage of removable partial dentures (RPDs) using a multivariate analysis. Sixty-seven patients, who had RPDs inserted at the Tohoku University Hospital between 1996 and 2001, participated in this study. Data were collected from patients' clinical records and a questionnaire. Of the 15 factors examined, significant associations were found between RPD usage and pain, color of the artificial teeth, and arrangement of the artificial teeth. These findings suggest that RPD usage is related to patient satisfaction with esthetics and an absence of pain. PMID:19149065

Koyama, Shigeto; Sasaki, Keiichi; Kawata, Tetsuo; Atsumi, Tomohiro; Watanabe, Makoto


Flexion characteristics of four-unit fixed partial denture frameworks using holographic interferometry.  


Flexion of a metal/ceramic fixed partial denture (FPD) framework under function can cause fracture of the porcelain or deterioration of the cement seal. This study evaluated the flexion under compressive load of a four-unit mandibular FPD replacing the second premolar and the first molar. Testing was accomplished with elapsed time holographic interferometry, using 39 porcelain fused-to-metal frameworks cast with a silver-palladium alloy. The results demonstrated that solder joints at the junction of the premolar and molar pontics flexed under a reduced compressive load and exhibited a higher failure rate than other connector designs. PMID:1356156

Goldstein, G R; Wesson, A; Schweitzer, K; Cutler, B



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


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. PMID:1100023

Lewis, A J



Investigation of the effect of three sprue designs on the porosity and the completeness of titanium cast removable partial denture frameworks  

Microsoft Academic Search

Statement Of Problem. Although titanium has been used to cast removable partial denture frameworks, the casting process is arduous and requires specialized equipment. Purpose. This study evaluated the ability of 3 sprue designs (tree, ball, and circular) to produce complete, void-free castings of removable partial denture frameworks made from commercially pure titanium. Methods And Material. A cast with a Kennedy

Hamda S. Al-Mesmar; Steven M. Morgano; Leonard E. Mark



Internal porosity of cast titanium removable partial dentures: Influence of sprue direction on porosity in circumferential clasps of a clinical framework design  

Microsoft Academic Search

Statement of Problem. Although internal porosity is a potential risk factor for clasp fracture, little is known about its frequency in the clasps of titanium removable partial dentures. Purpose. This study investigated the influence of the direction of auxiliary sprues on porosity in the circumferential clasps of a pressure-cast titanium removable partial denture. Material and Methods. Wax patterns of a

Ioana Baltag; Kouichi Watanabe; Haruka Kusakari; Osamu Miyakawa



In vitro investigation of marginal accuracy of implant-supported screw-retained partial dentures.  


Mismatch occurring during the fabrication of implant-supported dentures may induce stress to the peri-implant bone. The purpose of this study was to investigate the influence of two different alloys and the fabrication method on the marginal accuracy of cast partial dentures. Two laboratory implants were bonded into an aluminium block so that the distance between their longitudinal axes was 21 mm. Frameworks designed for screw-retained partial dentures were cast either with pure titanium (rematitan) or with a CoCr-alloy (remanium CD). Two groups of 10 frameworks were cast in a single piece. The first group was made of pure titanium, and the second group of a CoCr-alloy (remanium CD). A third group of 10 was cast in two pieces and then laser-welded onto a soldering model. This latter group was also made of the CoCr-alloy. All the frameworks were screwed to the original model with defined torque. Using light microscopy, marginal accuracy was determined by measuring vertical gaps at eight defined points around each implant. Titanium frameworks cast in a single piece demonstrated mean vertical gaps of 40 microm (s.d. = 11 microm) compared with 72 microm (s.d. = 40 microm) for CoCr-frameworks. These differences were not significant (U-test, P = 0.124) because of a considerable variation of the values for CoCr-frameworks (minimum: 8 microm and maximum: 216 microm). However, frameworks cast in two pieces and mated with a laser showed significantly better accuracy in comparison with the other experimental groups (mean: 17 microm +/- 6; P < 0.01). (i) The fit of implant-supported partial dentures cast with pure titanium in a single piece is preferable to that of those made with the CoCr-alloy and (ii) the highest accuracy can be achieved by using a two-piece casting technique combined with laser welding. Manufacturing the framework pieces separately and then welding them together provides the best marginal fit. PMID:15140174

Koke, U; Wolf, A; Lenz, P; Gilde, H



Use of an alternative pontic foundation technique for a fiber-reinforced composite fixed partial denture: a clinical report.  


This article describes the treatment of a patient for whom a fiber-composite laminate dowel and core and polyethylene fiber were used as a conservative alternative to provide a dowel-and-core and fixed partial denture foundation. The treatment plan included removing the existing restoration on the maxillary right first molar, placing a fiber-reinforced resin dowel and core for retention and reinforcement of the maxillary first premolar, and fabricating a definitive restoration using polyethylene fiber to reinforce the fixed partial denture. PMID:15867748

Ayna, Emrah; Celenk, Sema



Removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy: a case report.  


Various dental implants have been used, and high success rates have been reported. However, as their uses increase, implant failures have been reported. There are partially edentulous patients with an initial treatment plan of an implant-supported fixed partial denture. At times, one or more strategic implants fail to osseointegrate. In situations where financial, systemic, or local conditions preclude the use of a fixed partial denture, a well constructed removable partial denture can be an excellent treatment alternative. It has been reported that prosthesis support can be improved with the use of osseointegrated dental implants, with improved preservation and maintenance of existing hard and soft tissues around dental implants. This article describes the prosthodontic rehabilitation of a partially edentulous patient by the use of a removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy. This treatment option solved a difficult clinical problem derived from the failure of two strategic implants and provided the patient with an esthetic and functional prosthesis. PMID:15359156

Mijiritsky, Eitan; Karas, Sivan



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

PubMed Central

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 (?Strain). 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 ?Strain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum ?Strain was predominantly observed in a buccal direction. As the load was moved anteriorly the ?Strain 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.

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



Designing cobalt chromium removable partial dentures for patients with shortened dental arches: a pilot survey.  


The aim of this survey was to investigate the quality of prescription for the fabrication of cobalt chromium removable partial dentures (RPDs) that are used to extend the shortened dental arches (SDAs). A survey of four commercial dental laboratories located in northern England was conducted. The target of this survey was cobalt chromium RPDs that were requested to restore SDAs comprising the anterior teeth and 2-4 premolars. Dentists' prescriptions were scrutinised, and a special data collection form was completed accordingly. A total of 94 dentists' prescriptions and associated SDA casts were examined. Almost all the requested cobalt chromium RPDs were clasp-retained RPDs (97%). Scrutinising the 91 prescriptions for clasp-retained cobalt chromium RPDs showed that dentists' prescriptions did not have any instructions about the design of the partial denture in a considerable proportion of the cases (32%). Teeth to be clasped were identified clearly in 45% of the prescriptions. A majority of the dentists (64%) failed to provide any instructions about the design of the rests to be placed on the most posterior premolar abutment teeth. A considerable proportion of the dentists delegated the task of selecting the type of the major connector to the dental technician (41%). Only 21 (23%) of the examined casts had clearly defined rest seat preparation. The outcome of this pilot survey shows inadequate quality of prescription in designing RPDs for patients with SDAs. This finding has an ethical and clinical bearing and does not fit with current legal guidelines relevant to designing RPDs. PMID:21175736

Nassani, M Z; Devlin, H; Tarakji, B; McCord, J F



Development of Candida-associated denture stomatitis: New insights  

Microsoft Academic Search

Despite therapeutic progress, opportunistic oral fungal infectious diseases have increased in prevalence, especially in denture wearers. The combination of entrapment of yeast cells in irregularities in denture-base and denture-relining materials, poor oral hygiene and several systemic factors is the most probable cause for the onset of this infectious disease. Hence colonization and growth on prostheses by Candida species are of

Tatiana Pereira-Cenci; Altair Antoninha Del Bel Cury; Wim Crielaard; Cate ten J. M



Prospective 3-year study of cross-arch fixed partial dentures in patients with advanced periodontal disease  

Microsoft Academic Search

Statement of Problem. Several choices exist for the treatment of advanced periodontal disease. One is a combined periodontal and prosthetic treatment that includes cross-arch fixed partial dentures (FPDs). However, the outcomes of such therapy have been reported mainly from studies in Scandinavian countries. Purpose. The aims of this study were: (1) to longitudinally evaluate, after periodontal and prosthodontic treatment that

Seung-Won Yi; Gunnar E. Carlsson; Ingvar Ericsson



Single tooth replacement using a modified metal-ceramic resin-bonded fixed partial denture: a clinical report  

Microsoft Academic Search

This article describes the use of a modified metal-ceramic resin-bonded fixed partial denture (MMC RBFPD) as a conservative solution for the replacement of an incisor. It is a minimally invasive technique which does not discolor the abutment teeth.

Yoshiyuki Hagiwara; Hideo Matsumura; Seiji Tanaka; Julian B. Woelfel



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


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. PMID:23279200

Mysore, Ashwin Raghunandan; Aras, Meena Ajay



An introduction to concept mapping in dental education: the case of partial denture design.  


The aim of this paper is to present concept mapping as a tool for enhancing clinical dental education and develops the authors' argument for the use of concept mapping presented previously in the pages of this journal. Materials presented are based on data gathered from extensive observation of learning and teaching in a UK dental school, and upon a case study of student learning of removable partial denture design. Using examples developed with students and teachers, critical elements of the approach are illustrated which can be used to support dialogue between the two parties. This approach can be used to develop active teaching strategies and engaged learning approaches that support the development of clinical expertise. PMID:19196289

Kinchin, I M; Cabot, L B



Intraoral Repair of All Ceramic Fixed Partial Denture Utilizing Preimpregnated Fiber Reinforced Composite  

PubMed Central

All ceramic fixed partial dentures (FPD)s exhibit enhanced biocompatibility and esthetics as compared to metal-ceramic restorations. However, framework fractures are frequently reported especially when the connector dimensions are inadequate to withstand the high tensile stresses. The repair of the failed connector would be desirable rather than the complete removal and renewal since the latter is an expensive and time consuming procedure. Furthermore, the replacement or removal of the restoration for extra-oral repair purposes might increase the risk of destroying the entire restoration or damaging the abutment teeth during the removal. This article presents a direct intra-oral method that may be used to repair the connector fractures of all-ceramic FPDs which are otherwise clinically satisfactory. In the present technique, the connector is reconstructed intraorally utilizing composite resin restorative material reinforced with E-glass-fiber.

Turkaslan, Suha; Tezvergil-Mutluay, Arzu



Biomechanical Response in Mandibular Bone due to Mastication Loading on 3-Unit Fixed Partial Dentures  

PubMed Central

An understanding of functional responses in oral bone is a crucial component of dental biomechanics. The purpose of this study was to investigate the potential biological remodelling response during mastication on the mandibular pre- and post-insertion of a fixed partial denture (FPD). A series of three-dimensional (3D) finite element analysis (FEA) models were presented pre- and postextraction to determine the biomechanical responses to masticatory loading in the anterior mandible. Equivalent strains were analysed at lingual/buccal and mesial/distal areas of the premolar to molar region and quantified to anticipate bone remodelling response. Mandibular bone incorporating an FPD experienced substantially greater stress/strain magnitudes than that prior to placement of fixed prosthodontics, which is suggestive of engagements of bone remodelling. The results suggest similar outcomes to those reported clinically. Developing a simulation reflecting the outcomes of restorative treatment can provide meaningful insight into restorative treatment planning, clinical outcomes, and fixed prosthodontics designs.

Field, Clarice; Li, Qing; Li, Wei; Swain, Michael



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


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. PMID:10384169

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



Influence of implant inclination associated with mandibular class I removable partial denture.  


The aim of this study was to use two-dimensional finite element method to evaluate the displacement and stress distribution transmitted by a distal extension removable partial denture (DERPD) associated with an implant placed at different inclinations (0, 5, 15, and 30 degrees) in the second molar region of the edentulous mandible ridge. Six hemimandibular models were created: model A, only with the presence of the natural tooth 33; model B, similar to model A, with the presence of a conventional DERPD replacing the missing teeth; model C, similar to the previous model, with a straight implant (0 degrees) in the distal region of the ridge, under the denture base; model D, similar to model C, with the implant angled at 5 degrees in the mesial direction; model E, similar to model C, with the implant angled at 15 degrees in the mesial direction; and model F, similar to ME, with the implant angled at 30 degrees in the mesial direction. The models were created with the use of the AutoCAD 2000 program (Autodesk, Inc, San Rafael, CA) and processed for finite element analysis by the ANSYS 8.0 program (Swanson Analysis Systems, Houston, PA). The force applied was vertical of 50 N on each cusp tip. The results showed that the introduction of the RPD overloaded the supporting structures of the RPD and that the introduction of the implant helped to relieve the stresses of the mucosa alveolar, cortical bone, and trabecular bone. The best stress distribution occurred in model D with the implant angled at 5 degrees. The use of an implant as a support decreased the displacement of alveolar mucosa for all inclinations simulated. The stress distribution transmitted by the DERPD to the supporting structures was improved by the use of straight or slightly inclined implants. According to the displacement analysis and von Mises stress, it could be expected that straight or slightly inclined implants do not represent biomechanical risks to use. PMID:21415633

de Freitas Santos, Ciandrus Moraes; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; de Moraes, Sandra Lúcia Dantas; Falcón-Antenucci, Rosse Mary



Stress distribution of inlay-anchored adhesive fixed partial dentures: A finite element analysis of the influence of restorative materials and abutment preparation design  

Microsoft Academic Search

Statement of Problem. Indirect composite or ceramic fixed partial dentures (FPDs) have become an alternative to conventional metal-ceramic adhesive fixed partial dentures (AFPDs). Little information about the adequate restorative material and tooth preparation design for inlay-anchored AFPDs is available to the clinician. Purpose. The purposes of this simulation study were: (1) to use 2-dimensional finite element modeling to simulate stresses

Pascal Magne; Nikolaos Perakis; Urs C. Belser; Ivo Krejci



[Clinical study of tooth-to-implant supported fixed partial dentures].  


The lack of the periodontal ligaments around the implants results an ankylotic fixation. The mobility of the osseointegrated implants is only one tenth of the mobility of the natural teeth. To connect a natural tooth and an implant as abutments in a fixed restoration is a special problem in the dentistry. The aim of this study was to examine whether connecting of implants and natural teeth has any disadvantages for the abutment either implant or natural tooth. Furthermore we wanted to know if an overloading of the opposing tooth could occur because of the stiffness of the implant-bone connection. 21 partially edentulous patients, who were treated with implant supported bridges using the DenTi implant system which includes screw-shaped, commercially pure titanium implants, were examined. Plaque, calculus, gingival index, probing depth and bleeding on probing were recorded around the implants and the teeth. Mobility, sound on percussion were examined as well. In this study no disadvantageous effect of connecting teeth to implants as abutments by fixed partial dentures was found. There was no sign of a harmful effect of the implant to the opposing teeth either. The tooth-to-implant bridges function in their biological environment without affecting it adversely. PMID:9704564

Radnai, M; Fazekas, A; Vajdovich, I; Kostinek, D



An 18-year retrospective analysis of treatment outcomes with metal-ceramic fixed partial dentures.  


Purpose: The aim of this clinical retrospective study was to evaluate the survival and success rates of metal-ceramic fixed partial dentures (FPDs) made by dental students over an 18-year interval. Biologic and technical complications as well as patient satisfaction were recorded. Materials and Methods: Fifty-seven patients with 82 FPDs from an original group of 104 patients with 128 FPDs attended an approximate clinical 18-year follow-up examination. The mean follow-up period was 17.7 years (range: 17.1 to 21.3 years). Results: Nine FPDs were lost because of extraction of an abutment tooth, and 1 FPD was removed for esthetic reasons. Technical problems recorded included loss of cementation, fractures in the metal framework, and need for placement of a dowel in an abutment tooth. The most common clinical findings were gingival bleeding on probing and appearance of supragingival crown margins. The survival rate of the FPDs was 78%, and the established success rate was 71%. Conclusion: This 18-year follow-up of metal-ceramic FPDs in just over half of the originally treated patient group was associated with good patient satisfaction and few biologic and technical complications. Int J Prosthodont 2011;24:314-319. PMID:21716968

Napankangas, Ritva; Raustia, Aune


Numerical simulation of the casting process of titanium removable partial denture frameworks.  


The objective of this work was to study the filling incompleteness and porosity defects in titanium removal partial denture frameworks by means of numerical simulation. Two frameworks, one for lower jaw and one for upper jaw, were chosen according to dentists' recommendation to be simulated. Geometry of the frameworks were laser-digitized and converted into a simulation software (MAGMASOFT). Both mold filling and solidification of the castings with different sprue designs (e.g. tree, ball, and runner-bar) were numerically calculated. The shrinkage porosity was quantitatively predicted by a feeding criterion, the potential filling defect and gas pore sensitivity were estimated based on the filling and solidification results. A satisfactory sprue design with process parameters was finally recommended for real casting trials (four replica for each frameworks). All the frameworks were successfully cast. Through X-ray radiographic inspections it was found that all the castings were acceptably sound except for only one case in which gas bubbles were detected in the grasp region of the frame. It is concluded that numerical simulation aids to achieve understanding of the casting process and defect formation in titanium frameworks, hence to minimize the risk of producing defect casting by improving the sprue design and process parameters. PMID:15348628

Wu, Menghuai; Wagner, Ingo; Sahm, Peter R; Augthun, Michael



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


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. PMID:12202644

Oh, W; Götzen, N; Anusavice, K J



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


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. PMID:22806046

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



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


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. PMID:17117768

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



Finite Element Analysis of an Implant-Assisted Removable Partial Denture.  


PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. PMID:23551664

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



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

PubMed Central

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.

Triwatana, Premwara; Nagaviroj, Noppavan



Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology.  


The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible 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-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (?= 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm). OA had the highest median gap dimension (125 µm), followed by the AOT point (105 µm). CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. PMID:24036977

Borba, Márcia; Miranda, Walter Gomes; Cesar, Paulo Francisco; Griggs, Jason Allan; Bona, Alvaro Della


[Titanium-alloy vs. CoCr-alloy in removable partial dentures--a clinical study].  


Different types of titanium-alloys instead of CoCr-alloys have been tested as material for the framework of removable partial dentures (RPD). Adequate casting and processing techniques have been developed which enable to fabricate frameworks of complex designs and the problem limits porosity. This opened new possibilities for the use of titanium-alloys with improved properties (E-module). The aim of this study was to summarise the use of titanium in removable prosthodontics and to evaluate prospectively the use of the Ti6A17Nb-alloy for RPDs in a small group of patients. Two identically designed RPDs from CoCr-alloy (remanium GM 800+) and Ti6A17Nb-alloy (girotan L) were produced for ten patients. They had to wear each RPD during six months, first the CoCr-RPD and then the Ti6A17Nb-RPD. A questionnaire (visual analogue scale = VAS) was completed by the patients after one, three and six months of function for each RPD. Prosthetic complications and service needed were recorded. After the end of the entire observation period of twelve months, the patients remained with the Ti6A17Nb-RPD and answered the questionnaire after another six months. All parameters regarding the design of the RPDs were positively estimated by the dentist. Minimal, not significant differences were noted by the patients concerning comfort, stability and retention (VAS). Clinically, no differences in technical aspects or regarding biological complications were observed after six-months periods. The Ti6A17Nb-alloy (girotan L) for the framework of RPDs was judged by patients and professionals to be equivalent to RPDs made from CoCr-alloy. No differences in material aspects could objectively be observed. The Ti6A17Nb-alloy can be beneficial for patients with allergies or incompatibility with one or several components of the CoCr-alloy. PMID:19066155

Katsoulis, Joannis; Fischer, Jens; Huber, Sandra; Balmer, Sacha; Mericske-Stern, Regina



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


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. PMID:18551206

Shimizu, Hiroshi; Takahashi, Yutaka; McKinney, Thomas



Comparison of effects of bleach and cleansing tablet on reflectance and surface changes of a dental alloy used for removable partial dentures.  


Proper hygienic care of removable partial dentures is important for maintaining a healthy oral mucosa. A daily home care routine is the responsibility of the patient to maintain oral hygiene. A dentist must inform the patient about denture cleansers used for plaque control. Common denture cleansers may negatively affect the surface of alloys used to make partial dentures. The purpose of this study was to evaluate whether bleach and cleansing tablet have deleterious effects on the surface of a dental alloy used to fabricate removable partial dentures. Nineteen test specimens were prepared from CoCr dental alloy. The specimens were cast into 10 mm long x 10 mm wide x 1 mm thick. Fresh solutions made from a commercial bleach and a commercial cleansing tablet were used for each treating. Three groups (commercial denture cleansing tablet, bleach and tap water) were tested. Six specimens were immersed in 200 mL of tap water containing a single denture cleansing tablet. Two spoons of the commercial bleach was added to 200 mL of tap water. Seven specimens were treated. The control specimens were immersed in 200 mL of tap water. Six specimens were the control group. Each specimen was immersed for 30 min per day in the solution for a period of 30 days. The specimens were analyzed for reflectance with a spectrophotometer, for surface changes with a light microscope and weight which was measured with sensitive balance before and after treatment. The SPSS program was used for the statistical analysis. The Kruskal-Wallis Test and Wilcoxon Signed Ranks Test was used. No significant changes of reflectance was shown in the Kruskal-Wallis Test (p > 0.05). The Wilcoxon Signed Ranks Test was performed for comparison into groups. The difference between before and after treatment was statistically significant for the commercial denture cleansing tablet and the commercial bleach (p = 0.028) (p < 0.05). Reflectance was decreased after treatment. Within the limitations of this study, the commercial cleaning solutions had influenced the decrease of reflectance on the surface of the dental alloy. This solutions should not be limitlessly used on dentures with metal components, because they caused clinically significant reflectance changes on the surface of the alloy after 30 days. PMID:12873071

Keyf, Filiz; Güngör, Tayyar



A short-term clinical follow-up study of superplastic titanium alloy for major connectors of removable partial dentures  

Microsoft Academic Search

Statement of problem . Superplastic forming of Ti-6Al-4V alloy has been used in the fabrication of a removable denture framework. The method provides the titanium alloy denture framework with excellent physical properties not seen in cast titanium prostheses.Purpose . This study describes the technical procedure for fabricating removable dentures with this type of framework and evaluates clinical applications of the

Noriyuki Wakabayashi; Minoru Ai



Effect of masticatory load on crack deflection\\/penetration investigated with en-face optical coherence tomography in ceramic fixed partial dentures  

Microsoft Academic Search

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

Cosmin Sinescu; Meda Lavinia Negrutiu; Liviu Marsavina; Radu Negru; Mihai Hluscu; Cristiana Caplescu; Adrian Bradu; Michael Hughes; Mihai Rominu; Adrian Gh. Podoleanu



Using a fiber-reinforced composite fixed partial denture to restore a missing posterior tooth: a case report.  


With the advent of new adhesive technologies, fiber-reinforced composite fixed partial dentures (FRC-FPDs) have become an inexpensive, esthetic and useful restorative option for patients missing a single tooth. This article describes a case involving an inlay-retained FRC-FPD with a prefabricated fiber-reinforced pontic substructure. In addition, a 6-year follow-up is presented. The FRC-FPD fully restored the single missing molar with simple and conservative intracoronal preparations in the proximal teeth and was deemed clinically acceptable after the evaluation period. The clinical procedures to build a FRC-FPD with a prefabricated fiber-reinforced pontic substructure typically are finished by the clinician in 1 or 2 visits without laboratory assistance, making it a viable alternative for patients who cannot afford implant-based treatment or a conventional metal-ceramic FPD. PMID:23649577

Soares, Carlos Jose; Barreto, Bruno Castro Ferreira; Santos-Filho, Paulo Cesar de Freitas; Raposo, Luis Henrique de Araujo; Martins, Luis Roberto Marcondes


Effect of design of all-ceramic resin-bonded fixed partial dentures on clinical survival rate.  


In the treatment of single-tooth gaps, the resin-bonded fixed partial denture (FPD) has established itself as an alternative treatment modality. With the advent of high-strength ceramics, such as aluminum oxide ceramics, it appeared to be possible to fabricate all-ceramic resin-bonded FPDs without a metal reinforcement. However, fractures of the traditional two-retainer design of these restorations occurred quite frequently. It was proposed to change the two-retainer design to a single-retainer design with the hope that the survival rate could be improved. Nevertheless, the use of aluminum oxide ceramics can be problematic. The present study strongly suggests that the clinical performance of resin-bonded FPDs made of a high-strength glass-ceramic is in large measure dependent on their design. PMID:16642903

Ries, Stefan; Wolz, Juergen; Richter, Ernst-Jürgen



Stereophotogrammetric analysis of abutment tooth movement in distal-extension removable partial dentures with intracoronal attachments and clasps.  


This study applied the three-dimensional measurement technique of stereophotogrammetry to measure abutment tooth movement under occlusal loading as a function of intracoronal attachment and clasp design. Six distal-extension removable partial denture designs were studied: (1) RPI-mesial occlusal rest, proximal plate, buccal I-bar; (2) cast circumferential clasp; (3) P.D. locking semiprecision attachment; (4) Thompson dowel nonlocking semiprecision attachment; (5) McCollum precision attachment; and (6) Stern G/L precision attachment. The movement in microns was determined by computer analysis. The Thompson dowel semiprecision attachment generated the most abutment movement in a gingival direction. The clasp-retained designs generally had less total movement than the attachment designs. Clasps and attachments for the abutment teeth adjacent to the distal-extension bases generally moved more than the abutment teeth. PMID:1800731

Chou, T M; Eick, J D; Moore, D J; Tira, D E



International telephone code used for citizenship identification in a denture.  


This case report describes a simple method for identifying the citizenship of a denture wearer by marking the telephone country code number inside the denture base. A wax pattern for the denture framework was prepared on the refractory cast. A piece of embossing tape, containing the country code (81, Japan), Japanese prefectural code, and abbreviation of the dental clinic where the denture was fabricated, was placed on the metal framework. A titanium-aluminum-niobium (Ti-6Al-7Nb) alloy was cast in the mold, and the denture was then fabricated by the conventional method. The casting satisfactorily reproduced the embossed letters, and the plate was identifiable through the gingiva-colored acrylic denture base resin. Since an embossed metal plate integrated with the skeleton is embedded in the denture base resin material, the current denture marking technique serves as a simple procedure for insertion of an undegradable denture identification mark which makes it possible to identify the nationality of the denture wearer. PMID:18195519

Matsumura, Hideo; Shimoe, Saiji; Nagano, Kiyoshi; Tanoue, Naomi



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

Microsoft Academic Search

Statement of problem.The influence of the loss of posterior teeth on the condylar position and on temporomandibular disorders (TMDs) remains a controversial issue.Purpose.This study investigated whether prosthetic rehabilitation promoted modification of the condylar position in subjects without symptoms of TMDs.Material and methods.The temporomandibular joints (TMJs) of 12 women (age 37 to 74), all with existing maxillary complete dentures but no

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



A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years  

Microsoft Academic Search

Objectives: The objective of this systematic review was to assess the 5- and 10-year survival of combined tooth-implant-supported fixed partial dentures (FPDs) and the incidence of biological and technical complications. Methods: An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years.

Niklaus P. Lang; Bjarni E. Pjetursson; Ken Tan; Urs Bragger; Matthias Egger; Marcel Zwahlen


Dislodgement resistance of modified resin-bonded fixed partial dentures utilizing tooth undercuts: an in vitro study  

PubMed Central

STATEMENT OF PROBLEM Over the years, resin-bonded fixed partial dentures (RBFPDs) have gone through substantial development and refinement. Several studies examined the biomechanics of tooth preparation and framework design in relation to the success rate of RBFPDs and considered retention and resistance form essential for increase of clinical retention. However, these criteria required preparations to be more invasive, which violates not only the original intentions of the RBFPD, but may also have an adverse effect on retention due to loss of enamel, an important factor in bonding. PURPOSE The object of this in vitro study was to compare the dislodgement resistance of the new types of RBFPDs, the conventional three-unit fixed partial denture, and conventional design of RBFPD (Maryland bridge). MATERIAL AND METHODS Fifty resin mandibular left second premolars and second molars were prepared on dentiforms, according to the RBFPD design. After model fabrication (five group, n = 10), prostheses were fabricated and cemented with zinc phosphate cement. After cementation, the specimens were subjected to tensile loading at a cross head speed of 4 mm/min in a universal testing machine. The separation load was recorded and analyzed statistically using one-way analysis of variance followed by Duncan's multiple range test. RESULTS Group V, the pin-retained RBFPDs, had the highest mean dislodgement resistance, whereas specimens of group II, the conventional RBFPDs, exhibited a significantly lower mean dislodgement resistance compared to the other 4 groups (P < .05). There were no significant differences between group I, III, and IV in terms of dislodgement resistance (P > .05). Group V had the highest mean MPa (N/mm2) (P < .05). There was no significant difference between groups I, II, III and IV (P > .05). CONCLUSION Within the limits of the design of this in vitro study, it was concluded that: 1. The modified RBFPDs which utilizes the original tooth undercuts and requires no tooth preparation, compared with the conventional design of RBFPDs, has significantly high dislodgement resistance (P < .05). 2. The modified RBFPDs which utilizes the original tooth undercuts and requires minimal tooth preparation, compared with the conventional FPDs, has significantly no difference in retention and dislodgement resistance)(P > .05). 3. The pin-retained FPDs showed a high dislodgement resistance compared to the conventional three-unit FPDs (P < .05).

Doh, Re-Mee



Influence of ridge inclination and implant localization on the association of mandibular Kennedy class I removable partial denture.  


The aim of this study was to evaluate the tendency of displacement of the supporting structures of the distal extension removable partial denture (DERPD) associated to the implant with different inclinations of alveolar ridge and implant localizations through a two-dimensional finite-element method. Sixteen mandibular models were fabricated, presenting horizontal, distally descending, distally ascending, or descending-ascending ridges. All models presented the left canine and were rehabilitated with conventional DERPD or implant-retained prosthesis with the ERA system. The models were obtained by the AutoCAD software and transferred to the finite-element software ANSYS 9.0 for analysis. A force of 50 N was applied on the cusp tips of the teeth, with 5 points of loading of 10 N. The results were visualized by displacement maps. For all ridge inclinations, the assembly of the DERPD with distal plate retained by an anterior implant exhibited the lowest requisition of the supporting structures. The highest tendency of displacement occurred in the model with distally ascending ridge with incisal rest. It was concluded that the association of the implant decreased the displacement of the DERPD, and the anterior positioning of the implant associated to the DERPD with the distal plate preserved the supporting structures for all ridges. PMID:21558932

Cunha, Lígia Del' Arco Pignatta; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Goiato, Marcelo Coelho



Numerical simulation of dental bone remodeling induced by implant-supported fixed partial denture with or without cantilever extension.  


The current study aims to evaluate and compare the bony biomechanical response and possible long-term restorative consequences stemming from the use of two-unit fixed partial dentures (FPDs) with or without cantilever configuration. The numerical simulations of bone remodeling were performed using an adaptive strain energy density algorithm, which incorporates an overloading bone resorption process. A patient specific 3D finite element model of a maxillary bone with two absent central incisors was constructed on the basis of clinical computed tomography data. Two different implant-supported two-unit FPD models were developed. The simulated remodeling results were visualized by examining the variation of apparent bone density. Different bone responses under normal and overload conditions were compared quantitatively and qualitatively between the cantilever and non-cantilever models. The mechanical stress/strain distributions were also examined. Furthermore, the simulation results were compared with a similar clinical X-ray image of the implant site. This study revealed that bone resorption due to overloading was more severe in the cortical neck around the implant-supported cantilever FPD, as compared with the non-cantilever configuration, which is better for maintaining the overall health of bone tissue. It is expected that such simulation methodology can be helpful in improving longevity and reliability of future dental implants. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23873599

Wang, Chao; Li, Qing; McClean, Colin; Fan, Yubo



Corrosion of some selected ceramic alloys used in fixed partial dentures and their postsolder joints in a synthetic neutral saliva.  


The electrochemical behavior of several alloys used in the frameworks of fixed partial dentures and their corresponding postsolders was studied in artificial saliva as a function of chemical composition. Open circuit potentials and polarization resistances were measured. The general electrochemical behaviors between the cathodic domain and the oxidation of solvent were characterized using cyclic polarization. The possible galvanic corrosion of coupled parent and postsolder alloys was also studied. The polarization resistances were high or very high. During immersion, the noblest alloys stayed in the immunity domains of their base elements, whereas Ni-Cr alloys were quickly passivated. The oxidation of the noble elements occurred only when the alloys were exposed to very high potentials solely achievable by artificial means. However, problems of galvanic corrosion may occur between an alloy and its postsolder joint if they are both exposed to saliva. Such corrosion may lead to a weakening of the framework. The parent alloy was often potentially affected by such corrosion but with low exchange currents. PMID:19196322

De March, Pascal; Berthod, Patrice; Haux, Emeline; Greset, Victor



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

PubMed Central

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.

Viswambaran, M.; Agarwal, S. K.



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

PubMed Central

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.

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



Fatigue Behavior of Zirconia-Ceramic, Galvano-Ceramic, and Porcelain-Fused-to-Metal Fixed Partial Dentures.  


PURPOSE: This study evaluated the fatigue behavior of three fixed partial dentures (FPDs) before and after artificial fatigue testing. MATERIALS AND METHODS: Sixty, three-unit zirconia-ceramic (ZC), galvano-ceramic (GC), and porcelain-fused-to-metal (PFM) FPDs (N = 20) were fabricated. Ten specimens from each group were exposed to fatigue testing by being thermocycled (5 to 55°C, 10,000 cycles) and loaded (100,000 cycles, 50 N, 0.5 Hz). All specimens were then subjected to occlusal loading in a universal testing machine until fracture. The fractures were characterized using scanning electron microscopy. Data were analyzed using one-way ANOVA followed by Tukey's significant difference post hoc test and the paired t-test. The chi-squared test was used to evaluate the type of fracture (? = 0.05). RESULTS: The mean fracture loads of non-fatigued and fatigued specimens for ZC were 2434.9 ± 154.3 and 2333.1 ± 183.0 N, respectively; for GC were 1678.1 ± 211.6 and 1475.8 ± 227.9 N, respectively; and 1878.5 ± 176.5 and 1687.8 ± 162.2 N, respectively, for PFM restorations. Significant differences were observed between fatigued and non-fatigued specimens of both the GC group and PFM group (p < 0.05), but not between fatigued and non-fatigued ZC specimens (p > 0.05). Differences between the PFM and GC specimens were not statistically significant for fatigued or non-fatigued specimens (p > 0.05). Fracture types did not differ significantly among groups. CONCLUSIONS: ZC specimens were not significantly affected by fatigue, whereas GC and PFM specimens were affected. All tested restorations have the potential to withstand occlusal forces applied in the posterior region. PMID:23735078

Ero?lu, Zekiye; Gurbulak, Aysegul G



Fracture Resistance of Composite Fixed Partial Dentures Reinforced with Pre-impregnated and Non-impregnated Fibers  

PubMed Central

Background and aims The mechanical properties of fiber-reinforced composite fixed partial dentures (FPDs) are af-fected by fiber impregnation. The aim of this in vitro study was to compare the fracture resistance of composite fixed partialdentures reinforced with pre-impregnated and non-impregnated fibers. Materials and methods Groups (n=5) of three-unit fiber-reinforced composite FPDs (23 mm in length) from maxillary second premolar to maxillary second molar were fabricated on two abutments with pontic width of 12 mm. One group was fabricated as the control group with composite (Gradia) and the other two groups were fabricated with composite (Gradia) reinforced with pre-impregnated fiber (Fibrex ribbon) and non-impregnated fiber (Fiber braid), respectively. The specimens were stored in distilled water for one week at 37°C and then tested in a universal testing machine by means of a three-point bending test. Statistical analysis consisted of one-way ANOVA and a post hoc Scheffé’s test for the test groups (?=0.05). Results Fracture resistance (N) differed significantly between the control group and the other two groups (P<0.001), but there were no statistically significant differences between the pre-impregnated and non-impregnated groups (P=0.565). The degree of deflection measured (mm) did not differ significantly between the three groups (P=0.397), yet the mean deflection measured in pre-impregnated group was twice as that in the other two groups. Conclusion Reinforcement of composite with fiber might considerably increase the fracture resistance of FPDs; how-ever, the type of the fiber used resulted in no significant difference in fracture resistance of FPD specimens.

Mosharraf, Ramin; Torkan, Sepideh



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.  


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. PMID:20002922

Stevenson, Richard G; Refela, Jane A



Fifteen-year clinical performance of a resin-bonded fixed partial denture seated with a thione primer and a tri-n-butylborane-initiated luting agent.  


This article reports the clinical performance of a resin-bonded fixed partial denture (FPD) made of type IV gold alloy. The retainers were air-abraded with alumina particles and primed with a single-liquid thione priming agent (Metaltite). The FPD was then seated with a tri-n-butylborane-initiated adhesive resin (Super-Bond). After 15 years, the FPD is still functioning satisfactorily. The present materials and techniques are applicable to minimally invasive fixed prosthodontic treatments. (J Oral Sci, 55, 263-266, 2013). PMID:24042595

Nakamura, Mitsuo; Matsumura, Hideo



Injuries sustained in rugby by wearers and non-wearers of mouthguards  

Microsoft Academic Search

Previous studies have shown a higher prevalence of head and neck injuries in non-wearers when compared with wearers of mouthguards. The purpose of the present study was to compare the pattern of injuries to those of past studies and also to investigate whether the injuries sustained differed significantly between wearers and non-wearers. A sample of 321 university students participating on

J B Blignaut; I L Carstens; C J Lombard



Denture Identification.  

National Technical Information Service (NTIS)

In the United States there is no standard method of identifying dentures. Should an edentulous individual be involved in a disfiguring disaster, it might be difficult to identify him unless his dentures were uniquely marked. A method is suggested for impr...

A. C. Jerman C. D. Miller



Color stability of long-term soft denture liners.  


The use of resilient denture liners in complete denture construction has become increasingly popular for providing comfort for denture wearers. The primary disadvantage of these materials is that the physical and mechanical properties change rapidly with time in a service environment. The purpose of this study is to evaluate the color stability of five commercially available soft denture liners as a function of accelerated aging. Color measurements were made before aging with a colorimeter and data processor. The samples were then weathered for 100 hours in an accelerated aging chamber in the presence of a xenon ultraviolet visible-light source, an intermittent water spray at 110 degrees F, and 90% humidity. After aging, color measurements were made again and color differences (delta E) were calculated. Results were statistically tested with analysis of variance and Scheffé intervals were calculated at 0.96. It was concluded that accelerated aging can be used to evaluate color stability of soft denture liners. PMID:1432811

Shotwell, J L; Razzoog, M E; Koran, A



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.  


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. PMID:20085617

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



Implant-Supported Denture  


... to implants. A regular denture rests on the gums, and is not supported by implants. An implant- ... supported denture daily to clean the denture and gum area. Just as with regular dentures, you should ...


Motion vector analysis of an abutment for a distal-extension removable partial denture: a pilot study.  


An investigation was conducted on the effect of various rest-clasp designs on abutment tooth movement when a testing prosthesis was subjected to vertical loading of the bilateral distal-extension base. The results did not reveal statistically significant differences among the rest-clasp designs tested. Variations in rest placement and/or clasp design had an effect on the magnitude and direction of force transmission to, and resultant movement of, the abutment tooth. Less force to the abutment tooth was recorded when a mesial rest was used with the rest-clasp designs as compared to a distal rest. Force transmission to the abutment was found to be greater when the vertical load was applied to the denture base on the same side than when applied to the opposite side of the denture base. PMID:6985668

McCartney, J W



Development of a Contemporary Animal Model of Candida albicans-Associated Denture Stomatitis Using a Novel Intraoral Denture System  

PubMed Central

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.

Johnson, Clorinda C.; Yu, Alika; Lee, Heeje; Fidel, Paul L.



Discrimination against contact lens wearers.  


Employers' attitudes toward the use of contact lenses at work have become less discriminatory as lenses have improved and numerous studies have demonstrated their safety, provided that additional personal protective equipment is used when necessary. In 1994, the Occupational Safety and Health Administration published its relevant Standard (29 CFR 1910), stating that "contact lenses do not pose additional hazards to the wearer...". Accommodations required by wearers of contact lenses must comply with Title I of the Americans with Disabilities Act. However, many companies still oppose their use. The recently published policy of the American College of Occupational and Environmental Medicine and the American Academy of Ophthalmology on the use of contact lenses should lead to their wider acceptance. Elements of a corporate contact lens policy are outlined. International aspects are summarized as well. PMID:9800172

Blais, B R



Fabrication of a maxillary posterior fixed partial denture with a type 4 gold alloy and a dual-polymerizing indirect composite.  


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. PMID:18403895

Matsumura, Hideo; Mori, Shuichi; Tanoue, Naomi



Denture Adhesives  


... bone and give temporary relief from loosening dentures. Zinc and Potential Risk Zinc is a mineral that is an essential ingredient for good health. ... in some dietary supplements. However, an excess of zinc in the body can lead to health problems ...


The influence of the alveolar ridge shape on the stress distribution in a free-end saddle removable partial denture supported by implant.  


The alveolar ridge shape plays an important role in predicting the demand on the support tooth and alveolar bone in the removable partial denture (RPD) treatment. However, these data are unclear when the RPD is associated with implants. This study evaluated the influence of the alveolar ridge shape on the stress distribution of a free-end saddle RPD partially supported by implant using 2-dimensioanl finite element analysis (FEA). Four mathematical models (M) of a mandibular hemiarch simulating various alveolar ridge shapes (1-distal desceding, 2-concave, 3-horizontal and 4-distal ascending) were built. Tooth 33 was placed as the abutment. Two RPDs, one supported by tooth and fibromucosa (MB) and other one supported by tooth and implant (MC) were simulated. MA was the control (no RPD). The load (50N) were applied simultaneously on each cusp. Appropriate boundary conditions were assigned on the border of alveolar bone. Ansys 10.0 software was used to calculate the stress fields and the von Mises equivalent stress criteria (sigmavM) was applied to analyze the results. The distal ascending shape showed the highest sigmavM for cortical and medullar bone. The alveolar ridge shape had little effect on changing the sigmavM based on the same prosthesis, mainly around the abutment tooth. PMID:22165315

Júnior, Manoel M; Anchieta, Rodolfo B; Rocha, Eduardo P; Pereira, João A; Archangelo, Carlos M; Freitas-Júnior, Amilcar C; Almeida, Erika O



Effect of proximal contact strength on the three-dimensional displacements of implant-supported cantilever fixed partial dentures under axial loading  

PubMed Central

Objective: This study investigated the effect of proximal contact strength on the three-dimensional displacements of cantilever fixed partial denture (CFPD) under vertically concentrated loading with digital laser speckle (DLS) technique. Methods: Fresh mandible of beagle dog was used to establish the implant-supported CFPD for specimen. DLS technique was employed for measuring the three-dimensional displacement of the prosthesis under vertically concentrated loading ranging from 200 to 3 000 g. The effect of the contact tightness on the displacement of CFPD was investigated by means of changing the contact tightness. Results: When an axial concentrated loading was exerted on the pontic of the implant-supported CFPD, the displacement of the CFPD was the greatest. The displacement of the prosthesis decreased with the increase of contact strength. When the contact strength was 0, 0.95, and 3.25 N, the displacement of the buccolingual direction was smaller than that of the mesiodistal direction but greater than that of the occlusogingival direction. When the force on the contact area was 6.50 N, the mesiodistal displacement of the prosthesis was the biggest while the buccolingual displacement was the smallest. Conclusions: The implant-supported CFPD is an effective therapy for fully or partially edentulous patients. The restoration of the contact area and the selection of the appropriate contact strength can reduce the displacement of the CFPD, and get a better stress distribution. The most appropriate force value is 3.25 N in this study.

Peng, Zhen-zhen; Chen, Xin-min; Wang, Jun; Li, Ai-jie; Xu, Zu-jie




EPA Science Inventory

The document reviews the risk of Acanthamoeba Keratitis for contact lens wearers. The document also reviews Granulomatous Amebic Encephalitis, another disease associated with Acanthamoeba in immune compromised individuals. Reports indicate that keratitis due to Acanthamoeba is a ...


Tear ferning in contact lens wearers.  


Tear ferning (TF) has shown good sensitivity and specificity in the diagnosis of dry eye, but is a relatively uncommon test, especially in contact lens wearers. The aim of this study was to investigate the relationship between TF, ocular comfort and tear film stability amongst contact lens (CL) wearers and non-contact lens (NCL) wearers. Subjects (36 NCL, 24 CL; mean age 23.2 +/- 4.8 years) underwent assessment of non-invasive tear break up time (NIBUT), fluorescein tear break up time (FBUT) and completed the Ocular Comfort Index (OCI) questionnaire. Non-stimulated tears were collected from the inferior tear meniscus with a glass capillary. Samples of 1.5 microL were air dried, observed by light microscopy and the TF pattern quantified according to Rolando's grading scale. Significantly higher grades of TF pattern and discomfort (higher OCI scores) were observed in CL wearers compared to NCL wearers (Mann-Whitney U-test; p < 0.005 and p < 0.05 respectively). Differences in tear film stability were not significant between groups. Even when asymptomatic (low OCI scores) CL and NCL subjects were compared, TF remained significantly different (p < 0.005). In both CL and NCL subjects, TF displayed poor correlation with tear film stability tests and OCI scores. Higher TF grades in CL wearers, even if asymptomatic, indicate an unfavourable ratio of salt to macromolecule concentration within the tear film of such subjects. The lack of significant difference in TF between symptomatic CL and NCL wearers could suggest similar aetiology (tear film hyperosmolarity) in each cohort. The TF technique demonstrates limited sensitivity and specificity for the prediction of ocular surface comfort in both CL and NCL wearers. PMID:19236590

Evans, Katharine S E; North, Rachel V; Purslow, Christine



A treatment protocol for restoring occlusal vertical dimension using an overlay removable partial denture as an alternative to extensive fixed restorations: a clinical report.  


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

Patel, Mit B; Bencharit, Sompop



Numerical analysis on the stress on the osseous tissues surrounding V-shaped thread denture implants  

Microsoft Academic Search

The theoretical and finite element models are founded for partial implanted dentures and for the osseous tissues surrounding the dentures implanted in the lower jaw area. The influences of threads type on partial denture repairing are studied. The results indicate that the stress on cortical bone is much larger than cancellous one. The maximum stress occurs at the mesial side

Ruan Hongyan; Song Xinhua; Liu Donglei; Yan Hua; Wang Xiao



[Study on the dynamic behavior of mandibular distal-extension removable partial denture utilizing finite element method. 2. Influence of the location of rest and displaceability of residual ridge mucosa].  


The purpose of this study is to investigate the denture design and displaceability of residual ridge mucosa and its relation to the load distribution on the remaining oral structures. In this study, the effects of the location of rest and displaceability of the mucosa were demonstrated utilizing the two-dimensional non-linear analysis reported on Part 1. The results were as follows. 1. Mesial rest could be simulated on the finite element model using pin element. 2. Removable partial denture with mesial rest distributed more stress on the mesial abutment teeth than that with distal rest. 3. Lesser displaceability of residual ridge mucosa resulted in a decrease of stress concentration around the most distal abutment and the uniform stress distribution on residual ridge was increased. 4. In the simulated condition where an increased pressure was applied on the mucosa, the behavior of the saddle on the mucosa with large displaceability could be similar to that of the mucosa with small displaceability. The results of this study suggested that mesial rest on the most distal abutment and pressure impression was desirable in removable partial denture with distal-extension. PMID:2489773

Nogawa, A



Retrospective analysis of prosthetic complications of implant-supported fixed partial dentures after an observation period of 5 to 10 years.  


Purpose: The purpose of this study was to evaluate the incidence of the most common technical problems with implant-supported fixed partial dentures (FPDs) and to assess the survival and success rates (event-free survival) after 5 to 10 years of function. Materials and Methods: All of the implants evaluated in this study were from a single manufacturer (Institut Straumann). Follow-up examinations were scheduled 1 week after suprastructure placement, 6 months later, and annually thereafter. Prosthesis-based data on survival/failure rates and technical complications were analyzed. Results: In 95 partially edentulous patients, 231 Straumann implants were placed and restored with 177 implant-supported prostheses (125 single crowns, 18 splinted crowns on two adjacent implants, and 34 three-unit FPDs). One hundred thirty one solid abutments and 100 synOcta abutments were inserted. The survival rate of prostheses supported by implants was 97.7%. The prosthetic success rate (event-free survival) was 96.05%. After an observation period of 5 years, the cumulative incidence of screw loosening was 0%. Fracture of the veneering porcelain occurred in 3.95% of all restorations. Fractures of the superstructure framework were not observed. The overall incidence of complications after 5 years was highest for splinted crowns, which showed the lowest success rate (94.4%), followed by three-unit FPDs (96%) and single crowns (98.4%). Conclusions: Single-unit restorations or short-span FPDs supported by both synOcta and solid abutments on Straumann implants showed low rates of technical complications, the most common being fracture of the veneering porcelain. PMID:24066321

Vanl?oglu, Burçin; Ozkan, Yasar; Kulak-Özkan, Yasemin


A clinical study to assess the breath protection efficacy of denture adhesive.  


This randomized and controlled, examiner-blind, 3-period, crossover clinical trial was designed to determine the effect of an experimental denture adhesive, a marketed denture adhesive (European Fixodent( Fresh), or no denture adhesive on the breath odor of 37 adults wearing full maxillary and mandibular dentures. Breath quality was measured at baseline and at 3 and 6 hours after the start of each treatment period via monitoring of volatile sulfur compounds (VSCs) using a halimeter and second-person organoleptic grading. A 48-hour washout phase separated treatment periods. There were no statistically significant differences in VSCs between any of the treatment regimens over 6 hours. Both the denture adhesive treatments were superior in breath quality improvement in organoleptic scores compared to no denture adhesive at 3 and 6 hours (p=0.0001). This research demonstrates the ability of both an experimental and marketed denture adhesive to deliver superior second-person breath benefits relative to no adhesive. The results indicate that Fixodent denture adhesives provide the denture wearer with a noticeable improvement in breath. PMID:12444398

Myatt, Graham J; Hunt, Sheri A; Barlow, Ashley P; Winston, J Leslie; Bordas, Alice; El Maaytah, Mohammed



Clinical morbidity and sequelae of treatment with complete dentures.  


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. PMID:9474536

Carlsson, G E



The effects of HEMA-monomer and air atmosphere treatment of glass fibre on the transverse strength of a provisional fixed partial denture resin.  


This study focused on some mechanical properties such as the transverse strength, the maximal deflection, and the modulus of elasticity of resin reinforced with two different types of agents-treated and with untreated glass fibre, and without fibre. A Teflon mould was used to prepare six groups of specimens. Two different types of chemical modification agents, hydroxyethyl-methacrylate (HEMA)-monomer and air atmosphere were applied to create hydrophilic surfaces on the glass fibres. The flow rate was kept at two different levels, 25 and 60 mL min-1. The discharge powers of the surface treatment process were 15 or 20 W. The fibres were exposed to glow discharge conditions for the periods of 10 or 15 min. Without fibre specimens were the control group. The provisional resin was same in all groups. All the specimens were subjected to transverse testing with a cross-head speed of 5 mm min-1. The three-point load test was used to record the load of the fracture for each specimens. The Kruskal-Wallis analysis of variance was used to compare the transverse strength, the maximal deflection and the modulus of elasticity. The differences in the transverse strength and the maximal deflection between the six groups were found statistically significant but the modulus of elasticity was not statistically significant. The transverse strength of HEMA-monomer (group A) was shown the highest value (66.3 MPa). For without-fibre group, the value was 52.9 MPa. This difference was statistically significant when the Mann-Whitney U-test was used for comparing. Repairing or remaking provisional restorations can be a time-consuming endeavour. The added strength of the polymethyl methacrylate with the fibre can reduce clinical failures of provisional fixed partial dentures. The surface treatment process was increased the transverse strength and the maximal deflection. The clinical implication of chemical modification agents-coated fibres is reduced incidence of fixed provisional restoration failure. PMID:14641682

Keyf, F; Uzun, G; Mutlu, M



Denture-Induced Stomatitis  


... denture-cleaning habits A build-up of the yeast Candida albicans , which can cause an infection Denture- ... a difference. If they don't fit right, yeast can build up underneath. People with type 2 ...


Comparison of castability and surface roughness of commercially pure titanium and cobalt-chromium denture frameworks  

Microsoft Academic Search

Statement of problem. Titanium is a biocompatible material, but it is not widely used in clinical dentistry for conventional removable denture frameworks. Little research exists on its applicability. Purpose. This study compared the casting accuracy and roughness of titanium and cobalt-chromium denture frameworks. Material and methods. Twenty Kennedy Class II, Division 1 removable partial denture frameworks were fabricated with commercially

Kyung-Soo Jang; Suk-Jin Youn; Yung-Soo Kim



Provision of a swing lock denture for a patient with Gorlin Goltz syndrome.  


Swinglock dentures are used relatively infrequently but in cases of compromised anatomy or where the pattern of tooth loss is unfavourable, they provide a useful removable partial denture design option. The aim of this article is to provide a clear summary of the clinical and technical considerations necessary when providing a Swinglock denture. PMID:23101181

Razaq, I; Durey, K; Nattress, B



Occurrence of Candida species colonization in a population of denture-wearing immigrants.  


Infection of the oral cavity and dentures by Candida species are frequent in denture wearers. C. albicans is the most common pathogen; however, other emerging Candida species are also responsible for this condition. Few data are available about the occurrence of Candida species in the oral cavities of denture-wearing immigrants to Italy. In this study, we compare the Candida species found in the oral mucosa and on dentures from a population of denture wearing immigrants to Italy to a matched Italian group. Oral swabs were collected from dentures and the underlying mucosa of patients enrolled in the study and were then cultured to test for the presence of Candida species in each sample. Out of 168 patients enrolled (73 Italians and 95 immigrants), 51 Italians (69.8 percent) and 75 immigrants (78.9 percent) tested positive for the presence of Candida. Candida albicans was the most frequently observed species overall; however, we found a higher occurrence of C. glabrata among immigrants than among Italians. In addition, immigrants displayed a higher incidence of Candida ? associated stomatitis and a lower mean age than Candida-positive individuals from the Italian group. Immigrants are more prone to longer colonization of the oral mucosa and dentures by Candida. In these patients, dentures must be checked periodically to prevent the presence of Candida. PMID:23527728

Calcaterra, R; Pasquantonio, G; Vitali, L A; Nicoletti, M; Di Girolamo, M; Mirisola, C; Prenna, M; Condo, R; Baggi, L


Clinico-pathological study on denture stomatitis.  


The clinical and pathological study was performed in order to determine the histopathological and cytoimmunological characteristics of denture stomatitis. All specimens were biopsy materials from seventeen patients with denture stomatitis. Normal palatal mucosae from ten patients served as the control. In addition to the usual staining methods, naphtol AS-D chloroacetate esterase stain and peroxidase-antiperoxidase method were used to detect mast cells and plasma cells. Denture stomatitis could be divided into atrophic and hyperplastic types. The former showed a smooth and atrophic mucosa. The latter showed a large number of exophytic projections which were composed of marked acanthosis and submucosal fibrosis, and was further subdivided into granular and papillary subtype according to the size of projections. In the present study, there were six cases of the atrophic type, and eleven cases of the hyperplastic type (consisting of seven granular and four papillary subtypes). The hyperplastic type was more frequently observed in patients with partial dentures compared with complete dentures and was associated frequently with ill fitting of the denture base as well as agglutination of denture plaque. Cytoimmunological study revealed that there was a pronounced increase of plasma cells, especially IgG- and IgA-producing cells, and a moderate increase of lymphocytes as well as mast cells in both types of denture stomatitis. Mast cells were always noted in the area with marked plasma cell infiltration, suggesting an intimate relation between both cells. These findings suggest that the immunological reactions play some role in the pathogenesis of denture stomatitis. PMID:3481390

Morimoto, K; Kihara, A; Suetsugu, T



Stressful pre-operative preparation procedures. The routine removal of dentures during pre-operative preparation contributes to pre-operative distress.  


One hundred and twenty-four patients (76 women and 48 men) were interviewed within the first 36 hours after operation. Fifty per cent of those studied were denture wearers. They were asked to fill in a questionnaire which registered their levels of distress about the various pre-operative preparation procedures. The most common factors contributing to pre-operative distress were waiting for transfer to the operating theatre, the prohibition of fluids and the removal of dentures. PMID:1781525

Cobley, M; Dunne, J A; Sanders, L D



Conservative and esthetic cast gold fixed partial dentures-inlay, onlay, and partial veneer retainers, custom composite pontics, and stress breakers: part II: utilization of additional retentive features and fabrication of custom pontic facings.  


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. PMID:20002923

Stevenson, Richard G; Refela, Jane A



Denture adhesive articles  

US Patent & Trademark Office Database

The present invention relates to a denture adhesive article comprising: a) a safe and effective adhesive amount of a water soluble denture adhesive component; b) a safe and effective amount of a component selected from the group consisting of a water soluble plasticizer, a water soluble carrier, and mixtures thereof; wherein the article is bioerodible; and wherein the article has dry tack.

Rajaiah; Jayanth (Loveland, OH); Wilder; Elizabeth Anne (West Chester, OH); Hamersky; Mark William (Fairfield Township, OH); Smith; Steven Daryl (Fairfield, OH); Scott; Douglas Craig (Loveland, OH)



Aortic ruptures in seat belt wearers.  


Several investigations have indicated that rupture of the thoracic aorta is one of the leading causes of immediate death in victims of road traffic accidents. In Finland in 1983, 92% of front-seat passengers were seat belt wearers on highways and 82% in build-up areas. The mechanisms of rupture of the aorta have been intensively investigated, but the relationship between seat belt wearing and injury mechanisms leading to aortic rupture is still largely unknown. This study comprises 4169 fatally injured victims investigated by the Boards of Traffic Accident Investigation of Insurance Companies during the period 1972 to 1985. Chest injuries were recorded as the main cause of death in 1121 (26.9%) victims, 207 (5.0%) of those victims having worn a seat belt. Aortic ruptures were found at autopsy in 98 victims and the exact information of the location of the aortic tears was available in 68. For a control group, we analyzed 72 randomly chosen unbelted victims who had a fatal aortic rupture in similar accidents. The location of the aortic rupture in unbelted victims was more often in the ascending aorta, especially in drivers, whereas in seat belt wearers the distal descending aorta was statistically more often ruptured, especially in right-front passengers (p less than 0.05). The steering wheel predominated statistically as the part of the car estimated to have caused the injury in unbelted victims (37/72), and some interior part of the car was the most common cause of fatal thoracic impacts in seat belt wearers (48/68) (p less than 0.001). The mechanism of rupture of the aorta in the classic site just distal to the subclavian artery seems to be rapid deceleration, although complex body movements are also responsible in side impact collisions. The main mechanism leading to rupture of the ascending aorta seems to be severe blow to the bony thorax. This also often causes associated thoracic injuries, such as heart rupture and sternal fracture. Injuries in the ascending aorta were mostly found in unbelted victims and were sustained in frontal impact collisions, the injury-causing part of the car being the steering wheel. Ruptures of the distal descending part of the aorta were frequently associated with fractures of the thoracic vertebra. PMID:2770317

Arajärvi, E; Santavirta, S; Tolonen, J



What Are Dentures?  


... problem. There isn't another one under the gum that can replace it. Unfortunately, this happens to ... they stick to the surface of a person's gums. Like wearing braces or a retainer, dentures can ...


Management of flabby ridges using liquid supported denture: a case report  

PubMed Central

Flabby ridges commonly occur in edentulous patients. Inadequate retention and stability of a complete denture are the often encountered problems in these patients. A liquid supported denture due to its flexible tissue surface allows better distribution of stress and hence provides an alternate treatment modality in such cases. This case report presents the use of a liquid supported denture in a patient with completely edentulous maxillary arch with flabby tissue in anterior region opposing a partially edentulous mandibular arch.

Aras, Meena Ajay; Chitre, Vidya



Denture labeling: A new approach  

PubMed Central

The need for denture labeling is important for forensic and social reasons in case patients need to be identified individually. The importance of denture marking has long been acknowledged by the dental profession. Over the years, various denture marking systems have been reported in the literature, but none till date fulfills all the prescribed ADA specifications. A simple, easy, inexpensive procedure for marking accurate identification marks on dentures with a lead foil is described here. The label caring the patient information is incorporated in the acrylic resin during the denture processing.

Bansal, Pardeep K.; Sharma, Akshey; Bhanot, Rajesh



[Occurrence and etiology of tooth caries in wearers of fixed dentures during the war].  


Concerning the destruction, war and caries are complemental. They don't have the same final causes, but on the microplan, both of them have destruction as a consequence. War causes complete destruction of organism, and the crude killing of human being. The people who do not get killed are faced to all negative etiological factors which disturb general health of organism. We have been following the parameter for the need of intervention in the field of dental protetic, frequent erosive changes of dental tissues sediments of caries and etiological factors which facilitate commencement and development lesions of caries on the tooth-carier of fixed protectical work. During this work we have been analyzing the patients who have been treated at The Clinic for Dental Health during the war in Bosnia and Herzegovina. Etiological factors, that caused commencement and development lesions of caries on the tooth-carier of fixed protetical work, are identical to those that are described in accessible literature, but also there have been some specific features which have been seen during the war conditions, as follows: *inadequate nutriment-patients were usually eating adhesive food, noodis, *impossibility of maintaining and providing the extents of oral hygiene, difficult or impossible access to a hygiene knot, *the lack of equipment for maintaining the oral hygiene, toothpaste, toothbrush, water, *Fight for the bare life, war is time for survival and it cites patient to seiftuiage in care for their own health, patient fights for existence and treats the acute states. In this relation brushing the teeth comes to the last place, *war conditions unable patients in approaching to therapeuts, and they can not use stomatological equipment due to the lack of electric power and water. *time as a factor--war circumstances delayed the intervention in the mouth of patient at the right time. Percent of sediments of caries inclinical study on the tooth-carier fixed protetical work is at the high level of 65%. This percentage could be justified by a fact that all patients came with already developed lesions of caries. War is enemy of human health in every segment, so increasing number of lesions of caries is one of the logical consequences. War in BiH has presented that stomatological science and practice during war are just curative. Esthetic stomatology and right-time interventions, preventions don't exist. There is only necessary stomatology. PMID:9601751

Redzepagi?, S



Marginal and internal adaptation of different superstructure and abutment materials using two different implant systems for five-unit implant-supported fixed partial dentures: an in vitro study.  


Purpose: To evaluate the marginal and internal adaptation of five-unit implant-supported fixed partial dentures with different superstructure and abutment materials with two different implant systems. Materials and Methods: Two mandibular epoxy resin models (one for each implant system) were fabricated, and implants were inserted in the canine, first premolar, and first molar regions. Thirty impressions of each model were then made. The 30 models of each group were divided into three subgroups: group 1, titanium abutment with metal (nickel-chromium) framework; group 2, titanium abutment with zirconium framework; and 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, and the data were evaluated statistically using analysis of variance and the least significant difference post hoc test. Results: The highest values for internal adaptation were observed at the occlusal surface in all groups. There were statistically significant differences in marginal measurements between subgroups. The smallest gaps were found in group 1 (79.361 ?m), and the largest gaps were found in group 3 (131.242 ?m). Conclusions: In this study, marginal and internal gap measurements were 79 to 131 ?m. The marginal discrepancy of the tested materials could be considered clinically acceptable. PMID:24066310

Kahramanoglu, Erkut; Kulak-Ozkan, Yasemin


Processing complete dentures.  


When this procedure is followed carefully, a strip of 0.0005-inch shim stock meets resistance when an attempt is made to withdraw it from between the teeth in occlusion and the incisal pin and its table simultaneously. Therefore, it is possible to process complete dentures by using compression molding and external heat for polymerization. The procedure involves a precise step-by-step method with particular emphasis on (1) investing properly in dental stone, (2) packing only one denture at a time with only one mix of acrylic resin, (3) using minimum packing pressure with maximum flow time, (4) trial packing until no flash is evident, and (5) careful deflasking. PMID:8635618

Rudd, K D



Bonding of acrylic denture teeth to resin denture bases.  


Anterior teeth debonding from dentures is a common problem. This study tested the bond strength of denture teeth to two types of denture resin, with and without grooving the ridge-lap surface. Bond strength and fracture type of three different groups were compared: 1. Teeth bonded to heat-cured polymethyl methacrylate (PMMA); 2. Teeth bonded to pour-type PMMA; 3. Grooved teeth bonded to pour-type PMMA. Specimens were manufactured following ISO standard 22112. Force values at failure were analysed using one-way analysis of variance, using the mixed procedure with confidence interval of 95%. Types of failure were identified as adhesive, cohesive or combination. In descending order, mean failure forces were 418.55N (Group One), 367.55N (Group Two) and 290.05N (Group Three). There was no significant difference between the means of groups 1 and 2 (p = 0.0627). Group Three differed from both other groups (p < 0.001). Groups One and Two showed predominantly cohesive fractures wthin denture teeth (83% and 72% respectively); group Three showed predominantly cohesive fractures within the denture PMMA (75%). Without ridge-lap modification, the bond strengths of denture teeth to pour-type and heat-cured denture resin were similar. Failures were predominantly of cohesive nature within the teeth themselves. Grooving the ridge-lap reduced fracture resistance and led to breakages predominantly in denture PMMA. PMID:23185939

Geerts, G A V M; Stuhlinger, M E



Conjunctival cytology in asymptomatic wearers of soft contact lenses  

Microsoft Academic Search

Conjunctival epithelium was systematically investigated with impression cytology in clinically asymptomatic wearers of soft contact lenses who had been using their lenses for several years. Severe abnormalities were observed, which had so far only been seen in diseases of the ocular surface mainly in dry eye syndromes. All patients showed evidence of squamous metaplasia with distinctly enlarged, flattened cells without

Erich Knopl; Horst Brewitt



Clinical performance of a light-cured denture base material compared to polymethylmethacrylate--a randomized clinical study.  


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. PMID:21655910

Gohlke-Wehrße, Hanna-Lena; Giese-Kraft, Katja; Wöstmann, Bernd



Lens replacement habits in soft contact lens wearers.  


The aim of this paper was to assess soft contact lens replacement habits of patients of Contact Lens Clinic, Zagreb University Hospital Department of Ophthalmology, Zagreb, Croatia. During spring of 2010, a survey was conducted in Contact Lens Laboratory, Zagreb University Hospital Department of Ophthalmology, Zagreb, Croatia. 47 completed surveys were collected and analyzed. The results of the survey have shown that the majority of soft contact lens wearers wear them longer than recommended by the manufacturer. It also showed that they eventually replace the lenses in regular intervals, indicating that they base their lens replacement on constant criteria. The main reasons for the eventual lens replacement were increased blur or discomfort while wearing lenses. Since it is obviously impossible to convince all lens wearers to replace their lenses as recommended by the manufacturer, it is up to the contact lens practitioners to find the way to reduce the risks of lens overwear. It may be achieved by introducing a method that will enable each soft contact lens wearer to choose an optimal lens replacement regimen without risking their eye health. PMID:23837240

Petricek, Igor; Lovri?, Ivana; Pokupec, Rajko; Jandrokovi?, Sonja



Influence of a wearer's voice on noise dosimeter measurements.  


In recent years, interest in personal noise exposure has expanded beyond a workplace safety measure to become an effective means of investigating physiological effects of the acoustic environment on an individual. This work investigates the effects of the wearer's voice as a possible dominant sound source on body-mounted noise dosimeters and develops methods to improve the application of dosimeter measurements in medium-level noise environments. Subjects experienced a controlled set of acoustic conditions while wearing a dosimeter. In each condition, sound pressure levels were recorded with and without the subject speaking controlled phrases. Three experimental variables were considered-room type, noise type, and noise level. All three variables had a statistically significant effect upon the contribution of speech to a dosimeter measurement; for example, noise level was shown to cause a change in speech contribution by as much as 5.5 dB between sequential levels. Based upon the analysis, a method of predicting the decibel contribution of a wearer's voice was developed. The results of this study can be used to estimate the effect of a wearer's voice on dosimeter measurements in medium-level noise environments. PMID:22352493

Ryherd, Steven; Kleiner, Mendel; Waye, Kerstin Persson; Ryherd, Erica E



Lens hygiene and care system contamination of asymptomatic rigid gas permeable lens wearers  

Microsoft Academic Search

Rigid gas permeable contact lenses are associated with fewer serious adverse reactions and thereby offer an increased margin of safety despite a perceived less strict adherence to sterile care system components. This article presents the lens care habits and frequency of care system contamination found in asymptomatic rigid gas permeable lens wearers. Forty-one asymptomatic rigid lens wearers presented for study.

Larry J. Davis



21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...



21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Preformed plastic denture tooth. 872.3590 Section...Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated...



Addressing problems in complete dentures.  


The authors have compiled a set of solutions to the most common issues influencing the success of complete denture cases. A brief review and discussion of occlusal vertical dimension is presented, followed by a troubleshooting guide to problems such as inadequate retention and stability, discomfort, and other problems affecting treatment outcome. PMID:18018388

LaBarre, Eugene; Giusti, Lola; Pitigoi-Aron, Gabriela



Rechargeable Infection-responsive Antifungal Denture Materials  

Microsoft Academic Search

Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin

Z. Cao; X. Sun; C.-K. Yeh; Y. Sun



A method for testing denture adhesives.  


An in vitro test method is described simulating the in vivo fate of a denture adhesive, i.e., destruction of the adhesive, dilution, and dissolution, by measuring the bond strength for the adhesive placed between acrylic resin plates. Between each measurement, the adhesive was exposed to isotonic saline. The bond strength for two ointment denture adhesives, Super Corega and Fixodent, was measured and the results were compared with those obtained for one of them in a previous in vivo test. The test method described for denture adhesives seems useful to depict the fate of a denture adhesive in clinical use. PMID:1791561

Fløystrand, F; Koppang, R; Williams, V D; Orstavik, J



Challenges, Attitudes and Practices of the Spectacle Wearers in a Resource-Limited Economy  

PubMed Central

Purpose: To evaluate challenges, attitudes and practices among spectacle wearers to effect positive change when necessary, and determine positive change in a resource-limited economy. Materials and Methods: A multi-hospital descriptive, cross sectional survey of spectacle wearers was conducted between May 2007 and December 2008 in Nigeria. Results: A total of 214 wearers comprising 43.5% males and 56.5% females aged 18-84 years were surveyed. The majority of subjects (92.6%) had at least secondary education. The wearers’ challenges included expensive spectacles (43.0%), falling/scratched/broken lenses (29.4%) and fear that spectacles would damage the eyes (23.8%). The wearers’ attitudes were comprised of consultations with ‘road side dispensers’ (7%) and permitting other individuals to select spectacle frames for them (26%). Care and maintaince practices included use of handkerchief, tissue paper, fingers and water to clean spectacles (49.5%) and placing spectacles inside spectacle cases (30.4%). There were no associations (P > 0.05) between gender or literacy levels and who selected the frames for the subjects, caregivers consulted for spectacles, and cleaning materials for spectacles. The placement of spectacles when not in use was significantly associated (P < 0.05) with the wearers’ gender and literacy levels but not with the length of spectacle wear. Conclusion: Attitudes and practices requiring positive change crossed gender and educational levels among spectacle wearers. The cost of spectacles should be regulated and availability of standard eye care practices would reduce challenges including lens-related defects and quackery. During consultation with a recognized eye care professional, counseling of wearers on positive attitudes/practices as well as allaying fear of spectacle wear is required.

Ayanniyi, Abdulkabir A.; Adepoju, Feyi G.; Ayanniyi, Rashidat O.; Morgan, Regina E.



An overview of removable partial overdentures.  


As an alternative to complete dentures, overdentures are well established as a sound therapeutic modality for patients with terminal dentition. By utilizing natural tooth roots and their periodontal structures to aid in support, overdentures maintain proprioceptive mediation and a mechanism for masticatory force vectors that favor bone retention over bond resorption. The degree of stability enhancement and denture retention from retained roots varies with the design and environment of the prosthesis. This article reviews various aspects of removable partial over-denture use. PMID:2198103

McDermott, I G; Samant, A



Rechargeable Infection-responsive Antifungal Denture Materials  

PubMed Central

Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be “washed out” by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions.

Cao, Z.; Sun, X.; Yeh, C.-K.; Sun, Y.



A survey of prosthetic eye wearers to investigate mucoid discharge  

PubMed Central

Background This study aimed to better understand the causes and treatments of mucoid discharge associated with prosthetic eye wear by reviewing the literature and surveying anophthalmic patients. Methods An anonymous questionnaire was completed by 429 prosthetic eye wearers who used visual analog scales to self-measure their discharge experience for four discharge characteristics: frequency, color, volume, and viscosity. These characteristics were analyzed with age, ethnicity, years wearing a prosthesis, eye loss cause, removal and cleaning regimes, hand-washing behavior, age of current prosthesis, and professional repolishing regimes as explanatory variables. Eighteen ocularists’ Web sites containing comments on the cause and treatment of discharge were surveyed. Results Associations were found between discharge frequency and cleaning regimes with more frequent cleaning accompanying more frequent discharge. Color was associated with years of wearing and age, with more years of wearing and older people having less colored discharge. Volume was associated with cleaning regimes with more frequent cleaners having more volume. Viscosity was associated with cleaning regimes and years of wearing with more frequent cleaning and shorter wearing time accompanying more viscous discharge. No associations were found between discharge characteristics and ethnicity, eye loss cause, hand washing, age of current prosthesis, or repolishing regimes. Forty-seven percent of ocularists’ Web sites advised that discharge was caused by surface deposits on the prosthesis, 29% by excessive handling of the prosthesis, and 24% by other causes. Conclusions A standardized treatment protocol for managing discharge is lacking. More frequent prosthesis removal and cleaning was associated with more severe discharge, but the direction of cause and effect has not been established. Professional repolishing regimes had limited impact on discharge experience. Further research into the socket’s response to prosthetic eye wear, including the physical, chemical, and biological elements of the conjunctiva, the socket fluids, and the deposits that cover the prosthetic eye is recommended.

Pine, Keith; Sloan, Brian; Stewart, Joanna; Jacobs, Robert J



The Effects of Removable Denture on Swallowing  

PubMed Central

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.

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



Sensitivity Pattern of Bacteria Isolated from Contact Lens Wearers in the Faculty of Pharmacy, Karachi University Student Population  

Microsoft Academic Search

Contact lens wearers are at great risk of developing microbial keratitis because of incorrect usages and unhygienic maintenance of contact lenses. Therefore, the present study was planned to provide data that will be helpful in selecting the anti-microbial to cure microbial keratitis. One hundred bacterial isolates from conjunctiva of contact lenses wearer were isolated, identified and subjected to in vitro

Nahia Rahim; Husan Bano; Baqir Naqvi


Mathematical analysis and experiment on the corneal reflex test in spectacle wearers.  


An experimental study and mathematical analysis of the corneal reflex test was undertaken in spectacle wearers. In the experimental study, photographs were taken of the corneal reflex through spectacles and the conversion ratios determined as measured in degrees/mm. In the mathematical analysis, the magnification effect of the lens was elucidated by three methods: geometrical analysis; real measurement of magnification factor; and ray tracing analysis. The real measurement of the conversion ratios was in good agreement with the conversion ratios determined by the three mathematical analyses. These results clearly showed that the corneal reflex test can be clinically useful even in wearers of spectacles. PMID:7947553

Hatsukawa, Y; Koike, H; Sugimoto, S; Kasai, K; Fells, P



Mathematical analysis and experiment on the corneal reflex test in spectacle wearers.  

PubMed Central

An experimental study and mathematical analysis of the corneal reflex test was undertaken in spectacle wearers. In the experimental study, photographs were taken of the corneal reflex through spectacles and the conversion ratios determined as measured in degrees/mm. In the mathematical analysis, the magnification effect of the lens was elucidated by three methods: geometrical analysis; real measurement of magnification factor; and ray tracing analysis. The real measurement of the conversion ratios was in good agreement with the conversion ratios determined by the three mathematical analyses. These results clearly showed that the corneal reflex test can be clinically useful even in wearers of spectacles.

Hatsukawa, Y; Koike, H; Sugimoto, S; Kasai, K; Fells, P



21 CFR 872.3520 - OTC denture cleanser.  

Code of Federal Regulations, 2013 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3520 OTC denture cleanser. (a) Identification...or paste that is intended to remove debris from removable prosthetic dental appliances, such as bridges or dentures. The...



21 CFR 872.3560 - OTC denture reliner.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3560 OTC denture reliner. (a) Identification. An OTC denture reliner is a device...



21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a...



21 CFR 872.3570 - OTC denture repair kit.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false OTC denture repair kit. 872.3570 Section 872.3570 Food and...Devices § 872.3570 OTC denture repair kit. (a) Identification. An OTC denture repair kit is a device consisting of a...



A finite element analysis of a mandibular canine as a denture abutment.  


A two dimensional finite element model was made of a mandibular canine and its supporting bone. The model was used to show stress values associated with loading the tooth as a partial denture abutment before and after modification to include rest seat preparations in different positions. Axial load produced a low pattern of stress while load on the unprepared tooth produced a very high pattern of stress. The effectiveness of rest seats in reducing stress in the alveolar bone was confirmed. PMID:9171017

O'Grady, J; Sheriff, M; Likeman, P



[Occlusal vertical dimension in removable complete dentures].  


In removable complete dentures, the occlusal vertical dimension is an important factor for patients' satisfaction with aesthetics. An excessively reduced occlusal vertical dimension is especially likely to lead to complaints about aesthetics, whereas an increased occlusal vertical dimension may lead to discomfort and a decision not to wear the complete dentures. There are various methods for determining the occlusal vertical dimension in complete dentures, based on the vertical dimension in the rest position of the mandible or on phonetics. However, none of the methods have proven to be clearly superior, in terms of reliability, than the others. The assessment of the occlusal vertical dimension will become more reliable if several methods are used simultaneously. Moreover, knowledge of the characteristics of the ageing face is essential. PMID:22292357

den Haan, R; Witter, D J



21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Polyacrylamide polymer (modified cationic) denture adhesive...Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture...



21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.  

Code of Federal Regulations, 2013 CFR

...homopolymer and/or carboxymethylcellulose sodium denture adhesive. 872.3410 Section...homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification...homopolymer and/or carboxymethylcellulose sodium denture adhesive is a device...



Effect of sodium hyaluronate ophthalmic solution on peripheral staining of rigid contact lens wearers.  


We evaluated the efficacy of sodium hyaluronate ophthalmic solutions on 3 and 9 o'clock staining with rigid contact lens wearers in a double masked multicenter study involving four institutions and 43 patients. Both sodium hyaluronate (0.1%) and control ophthalmic solutions (artificial tears) without preservative were used. Patients were randomly divided into two groups. The test group received sodium hyaluronate ophthalmic solution, and the control group received artificial tears as a control ophthalmic solution. The agents were instilled six times per day for 2 weeks while patients wore contact lenses. Although subjective symptoms improved similarly in the two groups, slit lamp observation, corneal staining, and anterior segment photography demonstrated improved results in eyes having received sodium hyaluronate ophthalmic solutions. We conclude that sodium hyaluronate ophthalmic solution is effective and safe for treating 3 and 9 o'clock staining in rigid contact lens wearers. PMID:8565197

Itoi, M; Kim, O; Kimura, T; Kanai, A; Momose, T; Kanki, K; Yamaguchi, T; Ueno, Y; Kurokawa, M; Komemushi, S



Fluid Resin Technic of Processing Denture Bases.  

National Technical Information Service (NTIS)

The fluid resin technic of processing acrylic resin denture bases was recently adopted for use in the dental module of the Air Transportable Hospital. The new technic, described in detail in this review, utilizes a pourable auto-curing acrylic resin for t...

C. D. Miller G. L. Hall



DIY dentures--a case report.  


Minor self adjustments to dentures is a common finding. This case report describes do-it-yourself major adjustments to a removable prosthesis in an attempt to convert it to a fixed prosthesis and the resultant damage to the dental tissues. PMID:8996926

Jagger, D C; Harrison, A



Photoelastic stress analysis in screwed and cemented implant-supported dentures with external hexagon implants.  


The aim of this study was to assess the stress distribution of the retention systems (screwed and cemented) for implant-supported fixed partial dentures by means of photoelastic method. Two models were made of photoelastic resin PL-2 with 2 implants (phi = 4.00 x 10 mm) located in the second premolar and molar region in each photoelastic model, varying the retention system (screwed and cemented). The implant-supported fixed partial dentures were standardized and made of Ni-Cr alloy. Axial and oblique (45 degrees) forces of 100 N were applied on the occlusal surface by means of a Universal Testing Machine (EMIC-DL 3000; São José dos Pinhais, Paraná, Brazil). The results were observed and photographed in the field of a circular polariscope and qualitatively analyzed with the aid of computer software (Adobe Photoshop, San Jose, CA). The screw retention system presented the highest number of fringes when the loads were applied on the premolar, pontic, and molar and showed this behavior in all load applications, under axial and oblique loads. It was concluded that there was a better stress distribution and lower magnitude of stress on the cemented implant-supported dentures, under axial and oblique loads. Oblique load caused an increase in stress concentrations in all the models. PMID:20613577

Pellizzer, Eduardo Piza; Tonella, Bianca Piccolotto; Ferraço, Renato; Falcón-Antenucci, Rosse Mary; de Carvalho, Paulo Sérgio Perri; Alves-Rezende, Maria Cristina Rosifini



Microbial flora in eyes of current and former contact lens wearers.  

PubMed Central

Microbial flora from the right eye conjunctival sac of 84 consecutively presenting contact lens patients were compared with cultures from both surfaces of their lens after aseptic removal and with the flora of their storage cases. Similar results were obtained from contact lens and conjunctival cultures of each individual; however, there was no correlation between storage case isolates and lens or conjunctival flora, suggesting that in uncomplicated lens wear, the eye is highly efficient in eradicating microorganisms introduced via handling. Conjunctival flora during daily contact lens wear was similar to the conjunctival flora of a matched control group of non-lens wearers. However, bacteria that are considered to be part of the normal ocular flora were isolated significantly more often from former contact lens wearers. The data also indicated that the use of nonperoxide chemical lens disinfection was associated with a higher proportion of positive cultures for pathogenic microorganisms than the use of other forms of disinfection, for both current and former contact lens wearers. The isolation of potential pathogens was particularly common among elderly subjects using thick contact lenses for extended wear. These changes to conjunctival flora may contribute to the increased risk of ocular infection associated with contact lens wear.

Fleiszig, S M; Efron, N



Salvaging of adjacent fixed partial dentures using an overcasting technique.  


Occasionally, clinicians are faced with a situation in which a solitary tooth between two bridges requires extraction. When this type of situation occurs, we must ponder the dilemma of how to replace the missing tooth. Options include placing an implant where the tooth was extracted or remaking one large multiunit bridge. Implants are not always possible or practical, and remaking a multiunit bridge that involves the abutments of the two existing bridges can be challenging and becomes much more expensive to the patients. The overcasting technique is a treatment modality that offers a solution in these particular situations. PMID:9560705

Szikman, M; Silverstein, L H; Kurtzman, D



Functional impressions for complete denture fabrication. A modified jump technique.  


Tissue conditioners are used with great success in dentistry as functional impression materials for rebasing removable prostheses. In the rebase procedure, a functional impression is made in an existing denture to create a master cast. The orientation of the occlusal surface to the underlying tissue surface is captured with a reline jig or denture flask and transferred to the new denture base in what is called a "jump" in laboratory jargon. Functional impression methods are not commonly considered, however, for the fabrication of new dentures despite their popularity and ease of use. This article describes a modified jump technique for remaking complete dentures. The method uses functional impressions in existing maxillary and mandibular dentures to create master casts and to act as stabilized carriers for jaw relation records. More precise esthetic and phonetic assessments of the existing prostheses are accommodated, and prescriptive changes may be referenced to the current tooth arrangement. PMID:20446488

Haney, Stephan J; Nicoll, Roxanna; Mansueto, Michael



Prosthetic reconstruction using gingiva-colored ceramic agent in fixed partial restoration in a 24-year old patient.  


Achieving an optimal esthetic result when replacing missing anterior teeth with a fixed partial denture can be a challenge. This is especially true when interdisciplinary treatment is needed and the patient refuses this for personal or financial reasons. Here we report a clinical case where a fixed partial denture was used to change the incisor relationship and to restore the normal tooth and gingival tissue shape, morphology, and relationship by including artificial gingiva within the fixed partial denture when the patient refused lengthy and costly multispecialty treatment options. PMID:23674924

Sadaqah, Nasrin R; Tair, Jawad Ali Abu



Prosthetic reconstruction using gingiva-colored ceramic agent in fixed partial restoration in a 24-year old patient  

PubMed Central

Achieving an optimal esthetic result when replacing missing anterior teeth with a fixed partial denture can be a challenge. This is especially true when interdisciplinary treatment is needed and the patient refuses this for personal or financial reasons. Here we report a clinical case where a fixed partial denture was used to change the incisor relationship and to restore the normal tooth and gingival tissue shape, morphology, and relationship by including artificial gingiva within the fixed partial denture when the patient refused lengthy and costly multispecialty treatment options.

Sadaqah, Nasrin R; Tair, Jawad Ali Abu



Liquid supported denture-management of flabby ridges  

PubMed Central

The ideal properties of a denture are adequate rigidity on polished surface to bear masticatory forces and at the same time, flexibility and softness on the tissue surface for proper and even distribution of masticatory forces. The problem with conventional denture is rigidity of tissue surface; leads to uneven distribution of load. This drawback even worsens in the case of flabby, atrophic and unemployed ridges with excessive bone resorption. The liquid supported denture allows continued adaptation and eliminates the disadvantages of denture designs based on the application of temporary tissue conditioners or soft liners.

Mody, Pranav V.; Kumar, Girish; Kumar, Manish; Shetty, Brijesh



Complication rates and patient satisfaction with removable dentures  

PubMed Central

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.

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



Fatigue properties of acrylic denture base resins.  


Observations were made of fractured surfaces caused by flexural and tensile fatigue tests made in polymethyl methacrylate denture base resins (PMMA). In addition, the changes in dynamic viscoelastic and tensile properties of the materials along with fatigue propagation were investigated. In the tensile and flexural fatigue tests, both the fractured surfaces, which had striations on their surfaces and cracks near the fractured section, closely resembled each other in appearance. On the other hand, all of the tensile properties, such as elastic modulus, toughness and tensile strength, decreased with the increase of the number of stress cycles in the fatigue test. The storage modulus (E') of the material decreased gradually along with fatigue propagation over the whole range of temperatures tested. The loss modulus (E") and mechanical loss tangent (tan delta) increased slightly. The fatigue limit of four commercial denture base resins varied widely from one product to another. PMID:2490598

Fujii, K



A method for testing denture adhesives.  


An in vitro test is described that simulates the in vivo fate of a denture adhesive, namely destruction, dilution, and dissolution of the adhesive, by repeated measurement of tensile bond strength for the adhesive in isotonic saline over time. The bond strengths were measured under two different settings of the testing machine. The main compositions of three denture adhesive pastes, Fittydent, Fixodent, and Super Poli-Grip and one powder adhesive, Super Wernet's, were determined by infrared spectroscopy. The tensile bond strengths of these adhesives and those of pure tragacanth gum were subjected to a three-way analysis of variance. The Fittydent and Super Poli-Grip adhesives exhibited the best results over time. The most appropriate of the described methods for testing denture adhesives seem useful; however, when seen in relation to the results of a published clinical study where the patients were asked to evaluate the retention and the duration of some of these adhesives, there are indications that the clinical validity of the method might be improved if paste adhesives are tested at temperatures above 35 degrees C. PMID:7658401

Koppang, R; Berg, E; Dahm, S; Real, C; Fløystrand, F



Microbial contamination of contact lens storage cases and domestic tap water of contact lens wearers.  


Contact lenses have been widely used as an alternative to spectacles both in developed and developing countries. However, under certain circumstances, adverse responses can occur during contact lens wear and several microorganisms--including bacteria, fungi, and free living amoebae--can cause several eye infections in wearers. Extended wear of contact lenses is the major risk factor of eye infections such as microbial keratitis, besides contaminated contact lens storage case, contaminated lens care solutions, and inaccurate contact lens handling. In this study, we collected contact lens storage case and domestic tap water samples from 50 asymptomatic contact lens wearers. We determined that total aerobic mesophilic bacteria were isolated in 45 (90 %), Gram negative rod bacteria were isolated in 20 (40 %), Pseudomonas spp. were isolated in 2 (4 %) and fungi were isolated in 18 (36 %) out of 50 contact lens storage cases. Free living amoebae were not detected in investigated contact lens storage cases. At the same time, out of 50, total aerobic mesophilic bacteria were isolated in 34 (68 %), fungi were isolated in 15 (30 %) and free living amoebae were isolated in 15 (30 %) domestic tap water samples. No Gram-negative rod bacteria and Pseudomonas spp. were detected in investigated water samples. Two contact lens case samples and two tap water samples were excluded from the analysis for Pseudomonas spp. for technical reasons. According to our findings, inadequate contact lens maintenance during lens wear may result in the contamination of contact lens storage cases. This situation can lead to severe eye infections in contact lens wearers over time. PMID:23064864

Üstüntürk, Miray; Zeybek, Zuhal



An expedited technique for remaking a single complete denture for an edentulous patient.  


Traditional techniques for fabricating complete dentures commonly require 5 visits. Reduction of the number of visits and chair time for complete denture fabrication would be welcomed by dentists and patients. This article describes and illustrates clinical and laboratory procedures for fabricating a new denture for a patient with an existing complete denture. The procedure can be completed in 3 to 4 visits. PMID:17854625

Rodrigues, Antonio H C; Morgano, Steven M



Denture Adhesives: Do They Work? Do You Need Them?  


... They Work? Do You Need Them? Watch enough television and you could be convinced that everyone with dentures should use an adhesive. Talk to some dentists and you might be convinced that no one should use an adhesive. The reality lies somewhere between the extremes. Denture adhesive can ...


Bond strength of permanent soft denture liners bonded to the denture base.  


The purpose of this study was to characterize denture and soft liner adhesion and to determine the adhesive and/or cohesive strength of different soft tissue liners bonded to the denture base by use of a new technique. Two groups of five permanent soft liners (dry or exposed to water for 6 months) were tested by use of a tensile mode to characterize the failure characteristics of soft liners bonded to denture base resin. The method differed from previous test methods because of the specimen's ability to align axially during the test. The results indicated significant differences in the bonding of liners to the denture base, and light-cure systems exhibited the greatest amount of stress needed for failure. Low bond strength was observed when the adhesion was poor or when the cohesive strength of the soft liner was low and lead to pure adhesive or cohesive failure. When both adhesive and cohesive bonds were strong, failure occurred at high stresses. Combinations of adhesive and cohesive failures (mixed mode) were also observed in intermediate cases. PMID:8778383

Emmer, T J; Emmer, T J; Vaidynathan, J; Vaidynathan, T K



Evaluation of bond strength of denture teeth bonded to heat polymerized acrylic resin denture bases  

Microsoft Academic Search

The purpose of this study was to investigate bond strength between two commercially available plastic teeth, Vitapan (Vp) and Vivadent (Vv), and two commercially available denture base resins, Classico (C) and Triplex Hot (T), as affected by tooth surface treatment. Eight experimental groups, each consisting of 5 samples, were investigated according to the variables: tooth brand (Vv or Vp), resin

Guilherme Saavedra; Maximiliano Piero Neisser


[Contemporary methods and mobile denture cleansers and theirs significance for older population].  


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 be verbally instructed and showed about cleaning techniques, but also written instructions inform of brochure should be distributed in order to achieve better effects. PMID:22097118

Strajni?, Ljiljana; Doki?, Miodrag; Vucini?, Predrag


Comparison of immunofluorescence and culture for the detection of Actinomyces israelii in wearers of intra-uterine contraceptive devices.  


A direct immunofluorescence (IF) method was compared with traditional culture methods for the detection of Actinomyces israelii in endocervical and intra-uterine-device (IUD) smears from 124 IUD wearers. Of 11 specimens that gave positive results by IF, only one was positive by culture. Of the 10 patients with positive IF specimens, three (30%) had signs and symptoms suggestive of pelvic infection and no other pathogen was detected. Direct IF of cervical smears offers a simple, relatively cheap method to screen IUD wearers for A. israelii. Clinical management of such cases is discussed. PMID:1941993

Leslie, D E; Garland, S M



The cytotoxic effects of denture base resin sealants.  


Previous studies have shown that light-polymerized denture base resins have a cytotoxic effect on oral epithelial cells. The purpose of this in vitro study was to examine the effects of two denture base resin sealants when used on three light-polymerized denture base resins. Sample disks were examined for their effect on protein synthesis. Results indicate that one sealant protected the cells against toxic effects of the materials (P < .05), while one sealant enhanced toxicity up to 88% above that attributed to the resin alone. PMID:1307016

Lefebvre, C A; Schuster, G S; Richardson, D W; Barron, D J


Indirect evaluation of corneal apoptosis in contact lens wearers by estimation of nitric oxide and antioxidant enzymes in tears  

PubMed Central

Background: Contact lens induced trauma to the corneal epithelium results in increased release of inflammatory mediators. The keratocyte apoptosis is directly related to epithelial injury and has been correlated with increased production of nitric oxide. Potent antioxidant enzymes protect cells from oxidative damage by inactivating reactive oxygen species and thus inhibiting apoptosis. This study aims at determination of total nitric oxide and antioxidant enzymes in tears which will be an indirect criteria for assessing apoptosis. Materials and Methods: Nitric oxide and antioxidant enzymes were estimated in tears of 25 soft contact lens wearers and compared with 25 age and sex matched controls. Results: Statistically significant increase of nitric oxide (P<0.001), superoxide dismutase (P<0.001) and glutathione peroxidase (P<0.001) levels was seen in tears of contact lens wearers as compared to controls. There was also statistically significant increase in the levels of antioxidant enzymes, superoxide dismutase (P<0.05) and glutathione peroxidase (P<0.01), with increase in the total duration of contact lens wear in years. Conclusions: Increase in the level of nitric oxide and antioxidant enzymes in tears of contact lens wearers suggested that contact lens wear suppresses the process of apoptosis. However, it was also postulated that the increased levels of nitric oxide balances the anti-apoptotic activities of increased levels of antioxidant enzymes by its pro-apoptotic activity leading to protective outcomes in contact lens wearers.

Bhatia, R. P.; Dhawan, Shikha; Khanna, H. D.; Dash, Amitabh



Acanthamoeba spp. in domestic tap water in houses of contact lens wearers in the metropolitan area of Mexico City  

Microsoft Academic Search

A survey was carried out in the metropolitan area of Mexico City to determine the presence of Acanthamoeba in the tap water of houses of contact lens wearers. Water samples were taken from the mains water entry, bathroom sinks and storage containers (roof tanks, cisterns) of 27 houses; and from the solution contained in the contact lens cases. Samples were

Patricia Bonilla-Lemus; Gerardo A. Ramírez-Bautista; Claudia Zamora-Muñoz; María del Rocío Ibarra-Montes; Elizabeth Ramírez-Flores; María Dolores Hernández-Martínez



[Daily difficulties associated with full conventional dentures].  


The effectiveness of health services can be evaluated from the quality of life (QOL) standpoint. Thus, this study evaluated rehabilitation services using full conventional dentures (FCD) of Specialized Dental Care Centers (SDCC) in Rio Grande do Norte (RN) regarding daily difficulties associated with these dentures made between 2007 and 2009. A cross-sectional study was conducted with 138 users of these FCD, collecting data by clinical examination and a questionnaire based on the Oral Impacts on Daily Performances index. The Fisher and chi-square tests were used to test the association between the variables. The result was that 42% of users reported difficulties in executing oral activities due to FCDs. These difficulties were more frequent and intense in the activities of eating, speaking and smiling. In general, 58.7% of users did not have functional teeth. In relation to the clinical evaluation of FCDs, 57.2% of upper and 9.2% of lower FCDs were satisfactory. There was an association between difficulty and the absence of functional teeth, but not with inadequate FCDs. Thus, the SDCCs were effective in upper FCD rehabilitation, since the difficulties encountered are within the standard limitations of this type of rehabilitation. On the other hand, the cost-benefit of rehabilitation of lower FCDs must be evaluated. PMID:24061036

Machado, Flávia Christiane de Azevedo; Costa, Anna Paula Serêjo da; Pontes, Anna Lepríncia Bezerra; Lima, Kenio Costa; Ferreira, Maria Ângela Fernandes



[In vitro cytotoxicity of denture adhesives].  


Cell recovery from damage induced by four types of commercial denture adhesives (three powder types, three rubber types, two cream types and one tape type) was studied in vitro, using 3 tissue culture cell lines (L-929 cells, HEp-2 cells and Gin-1 cells). After cultivation with a denture adhesive for two hours, the cells were transferred to a normal culture environment, and their growth was evaluated. Two cytotoxicity tests, i.e., agar overlay test and extraction method, were also carried out. The pH value of the extract was moderately acidic in one powder type (Faston). By contrast, the extracts of the other types were in the neutral range. Cell recovery hardly occurred in the rubber type adhesives and, moderate in the powder types. Slight recovery was noted with the cream types and the tape type. The results of the agar overlay test and the extraction method differed from those of the cell recovery test. The powder type showed marked inhibition of cell growth. The effects of other specimens decreased in the tape type, cream types and rubber types. In the extraction method, the extracts obtained from each specimen did not affect cell growth. Among the cells used, Gin-1 cells showed a slightly higher rate of cell recovery. The discrepancy among the results obtained by the different methods was considered to be due to the state of the specimen and differences in testing conditions. This indicates the importance of selecting an appropriate testing method. PMID:2135506

Kakiuchi, H; Imai, K



Characteristics of denture thermoplastic resins for non-metal clasp dentures.  


Six thermoplastic resins and conventional acrylic resin were examined to characterize their mechanical and physical properties, water sorption, solubility, flexural strength, modulus of elasticity, tensile strength and color stability. Thermoplastic resins for non-metal clasp dentures exhibiting low water sorption and solubility offer hygienic advantages. Since they have a low modulus of elasticity and are easily manipulated, these materials make it possible for larger undercuts to be used for retention compared to acrylic resin. Not all of the thermoplastic resins tested fractured after the bending test in contrast to the conventional denture base resin, which fractured when tested beyond its proportional limit. It was also found that clinically noticeable staining may occur on the polyamide resins and polyethylene terephtalate resins. PMID:20644329

Takabayashi, Yota



Treatment planning: implant-supported partial overdentures.  


When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the implant-supported overdenture has several advantages, some in common with a removable partial denture. PMID:15915882

Chee, Winston W L



The effect of denture design and fixatives on the retention of mandibular complete dentures tested on a novel in-vitro edentulous model.  


The aim of this study was to evaluate the effect of the design (extension and adaptation) of a mandibular complete acrylic denture and the use of denture adhesives using a novel in-vitro edentulous model. The model is a highly anatomically accurate replica based on a moderately resorbed human mandibular edentulous arch. The model has been designed and fabricated by means of an elaborate clinical and technical process that employs synthetic elastomeric materials with properties that attempts to reproduce in-vitro characteristics of the soft tissues overlying the ridges and immediate reflected tissues. This model was used to measure and compare the retention of mandibular dentures ofvarying designs (well-fitting, over- and under-extended) with and without the aid of denture fixatives. Retention tests were conducted with different volumes of artificial saliva at a cross head speed of 50 mm/min with 4 equidistant holding points on the denture occlusal surface, using a universal tensile testing machine in an axial pull direction. The effect of three denture adhesives on denture retention was also tested on the same denture types at different times over a period of 5 hours and beyond. The in-vitro model presented can be effectively used to test the retention of mandibular complete dentures. The speed of dislodgement force and amount of saliva are important variables in mandibular denture retention. The retention of well-fitting dentures was statistically higher than that of ill-fitting dentures. A significantly higher retention force was needed to dislodge mandibular dentures (well and ill-fitting dentures) when using a denture adhesive. PMID:23888529

Johnson, A; Al-Kaisy, N; Miller, C A; Martin, N



The various methods and benefits of denture labeling  

PubMed Central

Labeled dentures can be important in identifying the owners in case of an accident, loss of memory, states of unconsciousness, being inadvertently misplaced on admission to a hospital or, in identifying the bodies of those who have died in a calamity. Positive identification through labeled dentures plays a key role in forensic scenario. Marking dentures has been considered as an important part of forensic dentistry, although no standardized method is followed. A number of labeling systems are available and can be broadly separated into either surface marking methods or inclusion systems. Each of the commonly described techniques is assessed with respect to their strengths and weaknesses. The more contemporary methods, though hi-tech, are expensive and may not be suitable for all dental practitioners to use. This article reviews the strengths and weaknesses of various methods involved in labeling dentures concluding by recommending that this valuable topic be included in the dental curriculum in India.

Datta, Pankaj; Sood, Sonia



Subscriber identity module: A new method for denture identification  

PubMed Central

This article describes a technique for placing subscriber identity module into a complete denture. The cards stores information in the form of text messages and contacts which is easily accessible with all mobile devices, thus enabling quicker identification.

Colvenkar, Shreya



Inhalation of a denture fragment complicating facial trauma.  


A case of facial trauma is presented, which was complicated by a denture fragment lodged in the larynx. This potentially life threatening event caused minor symptoms only. Its diagnosis and management are reported. PMID:3203093

Ong, T K; Lancer, J M; Brook, I M



Subscriber identity module: A new method for denture identification.  


This article describes a technique for placing subscriber identity module into a complete denture. The cards stores information in the form of text messages and contacts which is easily accessible with all mobile devices, thus enabling quicker identification. PMID:24130595

Colvenkar, Shreya



Reactive dentures: a novel approach to decrease residual ridge resorption.  


The need for reduction of traumatic forces transmitted through the prosthesis has long been recognised and studies have shown that either a soft acrylic resin/silicone rubber can serve as a stress distributor and absorb some of the forces applied to the teeth. These dentures permit reaction to impacting forces which allows independent movement of one or more teeth in function unlike the conventional dentures. A completely edentulous patient with adequate inter-ridge distance was selected for the case, the dentures with soft liner placed between the patient's teeth and denture base were fabricated. This report presents a completely new technique to reduce the ridge resorption and facilitate patient comfort. PMID:23576651

Reddy, Kesava K; Prasanna, Renuka G S; Sundaresh, K J; Mallikarjuna, Rachappa



21 CFR 872.3300 - Hydrophilic resin coating for dentures.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin...



Electromyography of masticatory muscles after denture relining with soft and hard denture liners.  


We evaluated electromyograms of masticatory muscles after denture relining with soft and hard liners. In total, 44 patients with complete dentures were studied: 22 underwent chairside relining of mandibular dentures with a soft, silicone-based liner (Mucopren Soft); the other 22 underwent relining with a hard, acrylic resin-based liner (Kooliner). Electromyograms of the masseter and temporal muscles were obtained before (T0) and 90 days after (T90) relining. Participants performed a maximum voluntary contraction (static test), on which percentage-overlapping coefficient (%), mandibular displacement (%), and standardized electromyographic activity, i.e., impact, (µV ? µVs %) were analyzed. Participants were also asked to chew a wafer, cereal bar, and peanuts (dynamic test) to determine symmetrical mastication index (SMI%), frequency (Hz), and impact. The data were analyzed using a generalized linear model (?= 0.05). On the static test, mandibular displacement was lower and impact was higher at T90, as compared with baseline. On the dynamic test, SMI and impact were higher after relining for all foods. Frequency at T90 was higher only during cereal and peanut mastication. There were no differences between groups except for greatest impact during wafer chewing in patients with hard liners. Relining with hard and soft materials increased electromyographic activity and improved masticatory function. There was little difference between groups. PMID:24042588

Pisani, Marina X; Segundo, Antonio L M; Leite, Vanessa M F; de Souza, Raphael F; da Silva, Marco A M R; da Silva, Cláudia H L



The oral hygiene and denture status among residential home residents  

Microsoft Academic Search

The aim of this study was to investigate the oral hygiene practices and denture status of elderly people living in a residential\\u000a home. One hundred one elderly people living in Gurcesme Zubeyde Hanim Residential Home, Izmir—52 women (mean age 75.5?±?7.8)\\u000a and 49 men (mean age 75.3?±?8.8)—participated in an interview. Their oral hygiene practices, self-perceived oral health, denture\\u000a status, and needs

Gülcan Coskun Akar; Safak Ergül



A Study of Factors Contributing to Denture Stomatitis in a North Indian Community  

PubMed Central

Factors like oral and denture hygiene, presence of saliva, age of the denture, and degree of colonization with Candida albicans are to be evaluated as local contributing factors for causing denture stomatitis. 100 patients aged 30 to 70 years were selected for the study. Among these, 70 patients were labeled test group showing signs of stomatitis and 30 patients as control group as they showed no inflammatory signs. Clinical tests included oral and denture hygiene evaluation, salivary measurements, and age of the dentures, and microscopic investigations were done. Results showed no significant differences between the two groups in terms of saliva, oral and denture hygiene habits, and denture age. Test group showed stomatitis in patients who were wearing dentures for 5 to 10 years compared to control group who were wearing dentures for 10 years and above. Denture age was proportional to Candida colonization and not to degree of inflammation. Significant differences were found in Candida colonization of the fitting surface of the denture between stomatitis and control groups. Poor denture hygiene habits are the most prominent contributing factor for denture stomatitis and colonization.

Naik, Amit Vinayak; Pai, Ranjana C.



Fracture toughness of denture base acrylics.  


Two types of fracture toughness specimen, the tapered cleavage (TC) and single edge notch (SEN), are compared. Their reproducibility, accuracy, and ease of preparation are investigated. The fracture toughness of four types of acrylic resin, heat cured, autopolymerized, injection molded, and high impact resistant, has been determined by one or both of the above methods. High impact acrylic proved too ductile for either of the specimens to be used to assesss K1c; however, these deviations from brittle behavior were revealed by the tests and some insight into impact resistance was gained. The SEN specimens proved capable of distinguishing between the fracture toughness characteristics of the four types of denture base acrylics and proved easy to fabricate. The TC specimens proved difficult to fabricate requiring specialized equipment; however, once made, the specimens revealed more of the fracture process than did the SEN specimens. PMID:7400192

Stafford, G D; Huggett, R; Causton, B E



Corrosive Injury of the Oral Cavity and Esophagus Caused by Some Denture Cleanser Powders.  

National Technical Information Service (NTIS)

Denture cleansers are frequently found in the American household since there are in excess of 16 million people wearing dentures. These ubiquitous products were thought to be without serious complications, but this belief was recently changed when a dentu...

A. L. Abramson R. L. Eason W. H. Pryor E. J. Messer



21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture... § 872.3420 Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture...Identification. A carboxymethylcellulose sodium and cationic polyacrylamide polymer...



Unusual case of methicillin resistant staphylococcus aureus and acanthamoeba keratitis in a non-contact lens wearer from Kashmir, India  

PubMed Central

Acanthamoeba species can cause a chronic, progressive, ulcerative keratitis of the eye, which is not responsive to the usual antimicrobial treatment and is frequently mistaken for stromal herpes keratitis. Acanthamoeba keratitis continues to be a burgeoning and unsolved problem. Although soft contact lens wear is reported as the major risk factor in other parts of the world, reports from India suggest that acanthamoeba keratitis is more common among non-contact lens wearers. An unusual case of coinfection with Acanthamoeba and methicillin resistant staphylococcus aureus (MRSA) as causes of corneal keratitis in a contact lens wearer from Kashmir, India, is reported. Recent findings have shown that MRSA uses amoebae to spread, sidestepping hospital and other protection measures. Cysts of the isolated Acanthamoeba tolerated an incubation temperature of 40°C, indicating a pathogenic species. This case highlights the importance of culture methods in the diagnosis of corneal infection and the choice of treatment regimen.

Lone, Rubina; Syed, Khurshid; Abdul, Rashid; Sheikh, Sajjad Ahmed; Shah, Faisal



Will there be a need for complete dentures in the United States in 2020?  

Microsoft Academic Search

Currently, there is much speculation among dental educators that the need for complete dentures will decline markedly in the future and that complete denture training should be removed from the dental curriculum. Estimates based on national epidemiologic survey data indicate that edentulism has declined by 10% every decade and that only 90% of edentulous adults obtain and wear complete dentures.

Chester W. Douglass; Annie Shih; Larry Ostry



"Denture marking" as an aid to forensic identification.  


"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. Denture marking or labeling is not a new concept in either Prosthetic or Forensic dentistry and its routine practice has been urged by Forensic dentists internationally for many years. Denture marking is accepted as a means of identifying dentures and persons in geriatric institutions or post mortem during war, crimes, and civil unrest, natural and mass disasters. Prosthodontists are playing very important role in forensic dentistry as they are concerned with fabrication of various prostheses 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. The main objective of this article is to discuss the various methods of denture marking and to emphasize the importance of denture marking for person identification in medico legal investigations. PMID:23997461

Mohan, Jayashree; Kumar, C Dhinesh; Simon, Paul



Acanthamoeba keratitis. A growing problem in soft and hard contact lens wearers.  


Eleven contact lens-wearing patients presented with Acanthamoeba keratitis. Eight cases were culture- and/or stain-positive for Acanthamoeba and three were presumed to have Acanthamoeba keratitis based on history and clinical findings. Six wore daily wear soft contact lenses, two wore extended-wear soft contact lenses, one wore a polymethylmethacrylate hard contact lens, one wore a gas-permeable hard contact lens, and one wore a Saturn lens (combined hard and soft lens). Four patients used distilled water and salt tablet saline, three used tap water and salt tablet saline, two used tap water rinse, two used well water rinse or storage, and one used intravenous (IV) saline. It is apparent that all contact lens wearers are at some risk for Acanthamoeba keratitis developing if proper contact lens care is not maintained. Of great concern is the inability of most current chemical sterilization methods to kill the organism if the lens becomes contaminated. Heat disinfection will kill Acanthamoeba trophozoites and cysts but the lens must not be placed into contaminated solutions afterward. Prevention is very important because medical and surgical treatment failures are frequent. Eye care practitioners who fit contact lenses are advised to use heat disinfection for low-water content stock soft contact lenses, and to use hydrogen peroxide without a catalyst for a minimum of 6 hours for all other stock lens fitting sets, to specifically inquire about contact lens care habits used by their patients, and to discourage the use of homemade saline solutions. PMID:3431835

Moore, M B; McCulley, J P; Newton, C; Cobo, L M; Foulks, G N; O'Day, D M; Johns, K J; Driebe, W T; Wilson, L A; Epstein, R J



Liquid-Supported Dentures: A Soft Option--A Case Report  

PubMed Central

Liquid-supported denture technique allows continued adaptation of denture to the mucosa both at resting and functional state. A complete denture prosthesis is unacceptable if it violates the foundation on which it rests. In this case, a technique for fabrication of a complete denture prosthesis that eliminates the disadvantages of tissue conditioners and soft liners (i.e., poor bond strength to acrylic, candidal colonization, etc.) and preserves the remaining tissues is described. Liquid-supported denture can be a permanent solution to some patients with problematic conditions like diabetes, xerostomia, atrophied ridge, and so forth.

Jain, Anoop; Puranik, Shivakumar; Jagadeesh, M. S.; Kattimani, Puttaraj; Akki, Savita; Kumar, Pawan; laxmi', Vijaya



Relationships between denture base resin cytotoxicity and cell lipid metabolism.  


Substances that elute from denture base resins may inhibit cell growth and disrupt various metabolic processes. This study investigated the effects on cell lipid metabolism of eluates from several denture base resins. Cultured oral epithelial cells were exposed in vitro to eluates of discs made from several denture base resins. Lipid metabolism of the cells was measured using isotopic labeling with 14C-acetate. Results demonstrated that the metabolism of several lipid classes found mainly in the cell membrane was altered by the resin eluates. Eluate from one resin caused the appearance of two previously unrecognized classes of lipids. The alterations of the cell lipids and the presence of the previously unrecognized lipids may be the basis for some clinically evident cytotoxic and allergic reactions. PMID:8595119

Schuster, G S; Lefebvre, C A; Dirksen, T R; Knoernschild, K L; Caughman, G B


Complete denture prescription--an audit of performance.  


The quality of clinical records obtained during the various stages of complete denture construction was assessed in a survey conducted in five large dental laboratories in 1989. The most common fault in approximately half of 188 upper and 158 lower impressions was overextension in the labial and buccal sulci. Of the 87 occlusal records examined, the rims indicated the intended incisal relationship in about 50% of cases. The border of the eventual denture was defined by the technician rather than by the dentist in most instances. The post-dam was prescribed by the dentist in only 16% of the 50 trial dentures inspected. It is argued that a major cause of the lack of prescription is the level of the NHS fee, coupled with the fact that the laboratory expenses are deducted from that fee. PMID:8476681

Basker, R M; Ogden, A R; Ralph, J P



[Complete removable dentures: a commitment to best efforts].  


The provision of complete removable dentures can, in legal terms, be defined as a commitment to perform the best of one's abilities. Indeed, the result or patient's satisfaction with the new dentures, is difficult to predict and is apparently not only dependent upon the dentist/denturist and variations in materials and techniques. The relationship between the dentist/denturist and the patient is complex, but influences to a large extent patient satisfaction. This is especially true in cases of patients with reduced residual alveolar ridges or other (oral) problems. When a complete removable denture is being prepared, the patient should be thought of as the dentist/denturists most reliable contributor. By way of preventing or preparing for possible legal procedures, a good patient record is of importance. The patient record should contain the information which the patient has provided, the patient's request for help, and the character of the patient's expectations for treatment. PMID:22292354

Eijkman, M A J



Temperature of denture base resin under different protocols of microwave irradiation.  


This in vitro study evaluated the temperature of dentures after different microwave irradiation protocols. Two complete dentures (one maxillary and one mandibular denture) were irradiated separately 4 times for each of the following 5 protocols: dentures immersed in water (G1- 6 min, G2- 3 min); dentures kept dry (G3- 6 min); dentures placed in the steam sterilizer (G4- 6 min, G5- 3 min). The final temperature of the dentures was gauged in a thin and in a thick area of each denture with an infrared thermometer. All groups presented an increase in the resin base temperature. The thin areas of the dentures underwent greater heating than the thick areas. There was no significant difference (p>0.05) between the final mean temperatures of dentures immersed in water for 6 (G1) and 3 min (G2). However, the final mean temperatures recorded in G1 and G2 exceeded 71°C and were significantly higher (<0.001) than the final mean temperatures recorded in the other groups. It may be concluded that denture base resins subjected to microwave irradiation immersed in water may be exposed to deleterious temperatures. PMID:22011894

Sesma, Newton; Gil, Carlos; Kolikauskas, William Antunes; Silva, Rafael Andrade; Pannuti, Claudio Mendes



Ceramic dentures manufactured with ultrashort laser pulses  

NASA Astrophysics Data System (ADS)

Conventional manufacturing of individual ceramic dental prosthesis implies a handmade metallic framework, which is then veneered with ceramic layers. In order to manufacture all-ceramic dental prosthesis a CAD/CAM system is necessary due to the three dimensional shaping of high strength ceramics. Most CAD/CAM systems presently grind blocks of ceramic after the construction process in order to create the prosthesis. Using high-strength ceramics, such as Hot Isostatic Pressed (HIP)-zirconia, this is limited to copings. Anatomically shaped fixed dentures have a sculptured surface with small details, which can't be created by existing grinding tools. This procedure is also time consuming and subject to significant loss in mechanical strength and thus reduced survival rate once inserted. Ultra-short laser pulses offer a possibility in machining highly complex sculptured surfaces out of high-strength ceramic with negligible damage to the surface and bulk of the ceramic. In order to determine efficiency, quality and damage, several laser ablation parameters such as pulse duration, pulse energy and ablation strategies were studied. The maximum ablation rate was found using 400 fs at high pulse energies. High pulse energies such as 200?J were used with low damage in mechanical strength compared to grinding. Due to the limitation of available laser systems in pulse repetition rates and power, the use of special ablation strategies provide a possibility to manufacture fully ceramic dental prosthesis efficiently.

Werelius, Kristian; Weigl, Paul



Dimensional change in dentures processed in silicone and stone moulds.  


Anecdotal evidence suggests that many dental laboratories are surrounding the teeth and gingival margins of the wax patterns for complete dentures with silicone laboratory putty prior to investing in dental stone or plaster to facilitate deflasking and polishing. This project investigates differences in dimension during processing when putty is used. Two groups of ten standardised dentures, one group with silicone, one group without were processed. Cross arch measurements were made before and after processing using an eight hour curing cycle followed by slow cooling. No statistically significant difference in change in dimension was observed between the two groups, indicating that this is an acceptable method. PMID:12051132

Sinclair, Gary F; Clark, Robert K F



A systematic review of impression technique for conventional complete denture.  


The importance of an in depth review of impression making for complete dentures lies in the assessment of the historical value of all the factors related to physical, biologic and behavioral areas and the time in which they were discussed and taught as well. This review documents the historical development of knowledge associated with scientific advancement from 1845 to the present year, i.e. 2009 related to impression procedures in conventional complete denture prosthesis. Search for articles was done through electronic media the Pubmed. PMID:21629453

Rao, Shubha; Chowdhary, R; Mahoorkar, S



Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: A pilot study  

PubMed Central

Aims: The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW) are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW. Materials and Methods: In this study 21 CLW (Mean age 23 ± 3 years; M-2, F-19), who were daily wear users, with duration of wear not more than four years, along with age-matched 28 controls (Mean age 28 ± 3; M-15, F-13) were recruited in the study for collection of reflex tears using Schirmer's strip. Ascorbic acid in tears was determined using high-performance liquid chromatography (HPLC), total antioxidant capacity (TAC) and total protein assay by spectrophotometric analysis. Results: CLW showed no significant change in the tear ascorbic acid levels (0.4 ± 0.26 mM) compared to the control subjects (0.61 ± 0.59 mM). The amount of ascorbic acid in tears did not correlate with the TAC or the total protein of the tears. The mean TAC in CLW was 0.69 ± 0.16 mM, with a total protein of 1.35 ± 0.46 mg/ml while in controls it was 0.7 ± 0.18 mM and 1.21 ± 0.47 mg/ml respectively. Conclusions: Soft contact lens wear did not show any significant change in tear ascorbic acid, TAC and total protein levels compared to controls.

Venkata, Sai Jyothi Aluru; Narayanasamy, Angayarkanni; Srinivasan, Vidhya; Iyer, Geetha Krishnan; Sivaramakrishnan, Ramakrishnan; Subramanian, Madhumathi; Mahadevan, Rajeshwari



A laboratory and clinical study of Trevalon denture base material.  


Trevalon is a denture base material which can be cured by three basic alternative curing cycles, thus providing a choice of processing technique which can be selected to suit laboratory or clinical needs. The flexibility of working properties is probably due to the interaction between on the one hand, the high molecular weight of the powder and on the other hand, the particle size distribution which are important factors influencing the doughing time (14 min), working time (40 min) and the exothermic reaction. The effect of each curing cycle upon the following properties of the material was investigated; dimensional accuracy, Young's modulus, modulus of rupture, impact resistance, water sorption, indentation resistance, creep and transverse bend behaviour. The particle size and molecular weight distribution of the powder were also evaluated. A clinical investigation of Trevalon was carried out by constructing complete dentures for a sample of patients, divided into three groups, each group having dentures processed by one of the three alternative curing cycles. Although some laboratory tests demonstrated that there were statistically significant differences between specimen bases, no clinical differences were recorded between dentures 1 year after construction. PMID:6957571

Murphy, W M; Huggett, R; Handley, R W



Effect on falls of providing single lens distance vision glasses to multifocal glasses wearers: VISIBLE randomised controlled trial  

PubMed Central

Objective To determine whether the provision of single lens distance glasses to older wearers of multifocal glasses reduces falls. Design Parallel randomised controlled trial stratified by recruitment site and source of referral, with 13 months’ follow-up and outcome assessors blinded to group allocation. Setting Community recruitment and treatment room assessments in Sydney and Illawarra regions of NSW, Australia. Participants 606 regular wearers of multifocal glasses (mean age 80 (SD 7) years). Inclusion criteria included increased risk of falls (fall in previous year or timed up and go test >15 seconds) and outdoor use of multifocal glasses at least three times a week. Interventions Provision of single lens distance glasses with recommendations for wearing them for walking and outdoor activities compared with usual care. Main outcome measures Number of falls and injuries resulting from falls during follow-up. Results Single lens glasses were provided to 275 (90%) of the 305 intervention group participants within two months; 162 (54%) of the intervention group reported satisfactory use of distance glasses for walking and outdoor activities for at least 7/12 months after dispensing. In the 299 intervention and 298 control participants available to follow-up, the intervention resulted in an 8% reduction in falls (incidence rate ratio 0.92, 95% confidence interval 0.73 to 1.16). Pre-planned sub-group analyses showed that the intervention was effective in significantly reducing all falls (incidence rate ratio 0.60, 0.42 to 0.87), outside falls, and injurious falls in people who regularly took part in outside activities. A significant increase in outside falls occurred in people in the intervention group who took part in little outside activity. Conclusions With appropriate counselling, provision of single lens glasses for older wearers of multifocal glasses who take part in regular outdoor activities is an effective falls prevention strategy. The intervention may be harmful, however, in multifocal glasses wearers with low levels of outdoor activity. Trial registration Clinical trials NCT00350855.



Efficacy of conventional and experimental techniques for denture repair.  


This study investigated the efficacy of one experimental and three conventional techniques for denture repair. Forty maxillary dentures were constructed in dental stone casts duplicated from an edentulous copper-aluminium maxillary master cast. Two groups of 20 dentures each were prepared with Lucitone 199 (water-bath, 8 h/74 degrees C) or Acron MC (microwave, 3 min/500 W) denture base materials processed in gypsum moulds. The 40 dentures were all separated sagittally in the middle. After that, five dentures of each denture base material were repaired with one of the four following techniques: L (Lucitone 199, water-bath, 8 h/74 degrees C, gypsum mould), A (Acron MC, microwave, 3 min/500 W, gypsum mould), AR (Acron MC/R, autopolymerized, 60 psi/45 degrees C/15 min) and the experimental technique AS (Acron MC, 1 min/500 W + 1 min/0 W + 1 min/500 W, hard silicone mould). The parameters denture accuracy (DA), horizontal (HC) and vertical changes (VC) of the occlusal plane measured the efficacy of the repair techniques. The DA was determined by weighing a film of silicone impression material set in contact to the tissue surface of the denture seated on the metallic master die. For HC, cross-arch measurements were made among reference marks drilled on the teeth 11, 21, 16 and 26. The VC was obtained by calculating the relative differences in height between similar teeth of each semi-arch (pairs 13-23, 14-24, 15-25 e 16-26). For DA, HC and VC, the percentage differences between the percentage means obtained before and after repair were calculated and grouped for comparisons. Analysis of variance (SuperANOVA) and means compared by Tukey-Kramer intervals (0.05) revealed that AR repair had the best percentage difference value for DA [0.5% (P < 0.05)], while the others were not statistically different [L = 27.2%, A = 28.9%, AS = 21.2% (P > 0.05)]. For HC, there was a statistical difference (P < 0.05) between AR and the other techniques for the tooth pairs, 16-26, 11-26 and 21-16; repairs with AR and AS differed for the 11-21 pair, while those with A and AS techniques differed for the 16-26 pair (P < 0.05). The VC differences were not detected between repair methods (P > 0.05). Denture accuracy was not affected by the interaction of base material-repair technique; repair with AR technique gave the best adaptation; the interaction of base material-repair technique did not affect HC; HC was affected by the repair technique. PMID:15525393

Rached, R N; Powers, J M; Del Bel Cury, A A



Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study  

PubMed Central

PURPOSE This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of 15 mm × 10 mm dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners.

Pahuja, Rasleen Kaur; Bansal, Sanjay



Partial Seizures  


... are subdivided into simple partial seizures (in which consciousness or awareness is retained) and complex partial seizures (in which consciousness is impaired or lost). Partial seizures may spread ...


Tensile bond strength of silicone-based soft denture liner to two chemically different denture base resins after various surface treatments.  


This study evaluated the effect of various surface treatments on the tensile bond strength of a silicone-based soft denture liner to two chemically different denture base resins, heat-cured polymethyl methacrylate (PMMA), and light-activated urethane dimethacrylate or Eclipse denture base resin. PMMA test specimens were fabricated and relined with a silicone-based soft denture liner (group AC). Eclipse test specimens were prepared according to the manufacturer's recommendation. Before they were relined with a silicone-based soft denture liner, each received one of three surface treatments: untreated (control, group EC), Eclipse bonding agent applied (group EB), and laser-irradiated (group EL). Tensile bond strength tests (crosshead speed = 5 mm/min) were performed for all specimens, and the results were analyzed using the analysis of variance followed by Tukey's test (p = 0.05). Eclipse denture base and PMMA resins presented similar bond strengths to the silicone-based soft denture liner. The highest mean force was observed in group EL specimens, and the tensile bond strengths in group EL were significantly different (p < 0.05) from those in the other groups. PMID:22447403

Akin, Hakan; Tugut, Faik; Guney, Umit; Kirmali, Omer; Akar, Turker



Cytotoxicity of eluates from light-polymerized denture base resins.  


This study examined the metabolic effects of eluates from four light-polymerized denture base resins and one heat-polymerized denture base resin on oral epithelial cells in vitro. The eluate was cell culture medium that contained either or both of apparently nonpolymerized components and reaction products that diffused out of the resin samples. Eluates were prepared by daily transfer of sample disks in a cell culture medium over 10 days. Toxicity of eluates was tested immediately after transfer (fresh) and after storage for 30 days (aged) by use of radioisotope incorporation and cell viability studies. The fresh eluates inhibited cell metabolism, whereas the aged eluates stimulated then inhibited the responses. Results suggest that the components that leach out of the tested materials do so at different rates and have prolonged toxic effects on cells. Thus soaking prosthesis in water before insertion may be beneficial. PMID:7853263

Lefebvre, C A; Knoernschild, K L; Schuster, G S



[Dentures and food selection. A survey in elderly women].  


Having complete dentures can have a negative influence on dietary intake and dietary composition, which can lead to an unhealthy situation, particularly for the elderly. In order to get more information on this subject, 86 women between 54 and 74 years old, who were treated at an university clinic, completed questionnaires about their chewing of and preference for various foodstuffs. From the results of this study the dietary intake of dietary fibres, protein and iron appeared to be lower in women with complete dentures. After correction for the total intake of energy these differences disappeared. The former group also indicated that they had more difficulties chewing bread, tough and soft meat, raw vegetables, apples and snacks. No differences were found concerning preference. PMID:11837090

Scheffers, M; ter Wee, J; van Staveren, W A; Stafleu, A



[Bending behavior of superplastic titanium alloy for denture base].  


The mechanical behavior of the Ti-6A1 4V alloy denture base made by superplastic forming was studied using various bending tests. The bending strength of the Ti-6A1-4V alloy plate made by superplastic forming was as strong as that of the casting Co-Cr alloy plate with the same thickness. The bending strength of the superplastic forming plate with channels was higher than that of the plain plate. Increase in the arch curvature of the plate decreased the strength, because increase in the arch curvature of the plate decreased the thickness of the superplastic forming plate. Similar results were obtained for the clinical models. The appropriate original thickness for superplastic forming denture base was derived empirically from the experimental values for depth of palate. PMID:2135518

Wakabayashi, N; Ai, M; Okuno, O



Simplified method for recording maxillomandibular relations in complete dentures.  


A simplified technique for recording maxillomandibular relations in complete dentures is described. This technique enables the practitioner to construct a mandibular occlusal mini-rim directly in the mouth, to adjust it to the required vertical dimension and to record the maxillomandibular relations during a single appointment. The mandibular record is formed with wax, used to hold the occlusal vertical dimension anteriorly, and impression plaster, to record the centric relation posteriorly. PMID:17508675

Boulos, Paul J



An investigation of complete denture teaching in the UK: part 2. The DF1 experience.  


Aim This paper, the second in a series of two (see  2013; 215: 177-181), investigates the opinions of a cohort of dental foundation year 1 (DF1) practitioners regarding their skills and competence in relation to their educational background in complete dentures.Materials and methods With the permission of the Dean of the London Deanery a questionnaire was emailed to the ten London Foundation year 1 training schemes for distribution to approximately 100 DF1s. Five schemes responded with total of 56 completed questionnaires (56%).Results The average number of complete dentures made as undergraduates was three. Forty-six percent had no experience in making copy dentures. An average of 2 (median 2.05) immediate replacement dentures were made; only 10% made 8-15 dentures. None had experience in implant-supported dentures. Thirty-five percent enjoyed their undergraduate training whereas 45% did not. Thirty-seven percent felt that their training had given them experience and confidence in complete dentures but 32% were of the opposite opinion. Sixty-three percent felt complete dentures were an important or very important aspect of dentistry. Six percent completely disagreed. The majority were confident in making impressions while 39% lacked confidence in registering jaw relations. Thirty-five percent were confident with chairside adjustments at the intermediary treatment stages but 28% were not. Sixty-three percent were confident in the fitting of new dentures and 64% with the after-care. There was no significant gender difference in the responses. There was a significant difference between the London and non-London trained DF1s. The London trained respondents made significantly fewer dentures than the non-London trained cohort. The latter also rated complete denture treatment as being more important. The comments section revealed that 43% felt that they had a lack of experience; only 5% were confident, 16% thought that complete denture treatment would become obsolete and only 5% recognised the continuing importance of complete denture treatment.Conclusion There is a disparity between the comments which indicate a lack of confidence in complete denture treatment and the response to the questionnaire. Other authors have commented on the lack of experience that has resulted in new graduates entering vocational training with little confidence in complete denture techniques. This report has highlighted these difficulties with respect to a current cohort of DF1s. PMID:24029990

Wieder, M; Faigenblum, M; Eder, A; Louca, C



Colour-Coded Mapping Technique in Impression Cytology – Findings in Soft Contact Lens Wearers and Patients with Other External Eye Diseases  

Microsoft Academic Search

This study aimed to demonstrate metaplastic changes in a wide area of conjunctival epithelium using the mapping technique by colouring different stages of metaplastic changes after marking them on a millimetric scale paper under a light microscope. Data of 23 patients were studied: 19 contact lens wearers, 2 cases with dry eyes, 1 with lagophthalmus, 1 with conjunctivitis, and 13

Canan Gürdal; Sevda Aydin



A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part V: Food preference comparisons  

Microsoft Academic Search

Statement of Problem. The functional benefits of replacing old dentures with new conventional mandibular dentures or implant-supported overdentures has not been fully determined. Purpose. This study assessed the impact of these 2 types of replacement dentures on the food choices of diabetic patients. Material and Methods. A total of 68 diabetic patients with original complete dentures participated in this study.

Eleni D. Roumanas; Neal R. Garrett; Michael O. Hamada; Randy M. Diener; Krishan K. Kapur



Application of sintered titanium alloys to metal denture bases: a study of titanium powder sheets for complete denture base.  


The purpose of this study was the fabrication of titanium powder sheets to enable the application of sintered titanium alloys as metal denture bases. The effects of titanium particle shape and size, binder content, and plasticizer content on the surface smoothness, tensile strength and elongation of titanium powder sheets was investigated. To select a suitable ratio of powdered metal contents for application as a metal denture base, the effects of aluminum content in Ti sheets and various other powder metal contents in Ti-Al sheets on the density, sintering shrinkage, and bending strength were evaluated. Based on the results of the above experiments, we developed a mixed powder sheet composed of 83Ti-7Al-10Cr with TA45 titanium powder (atomized, -45 microm), and 8 mass% binder content. This titanium alloy sheet had good formability and ductility. Its sintered titanium alloy had a density of 3.2 g/cm3, sintering shrinkage of 3.8%, and bending strength of 403 MPa. The titanium alloy sheet is clinically acceptable for fabricating denture bases. PMID:11484793

Doi, H; Harrori, M; Hasegawa, K; Yoshinari, M; Kawada, E; Oda, Y



21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Karaya and sodium borate with or without acacia denture...Prosthetic Devices § 872.3400 Karaya and sodium borate with or without acacia denture... (a) Identification. A karaya and sodium borate with or without acacia...



Halitosis Manifestation and Prevention Means for Patients with Fixed Teeth Dentures  

Microsoft Academic Search

SUMMARY The objective of this research is to analyse the causal relationship between construction of fixed bridge dentures and the intensity of halitosis manifestations, as well as to establish basic hygiene requirements for construction of fixed dentures which would completely exclude retention of food parti- cles and avoid bad breath. 48 patients (36 men and 12 women), who use fixed

Guntis Zigurs; Aldis Vidzis; Anda Brinkmane


A radiographic template for a two-implant mandibular overdenture using the patient's existing denture  

PubMed Central

This article introduces a technique for modifying an existing mandibular complete denture for use as a radiographic template with a radiopaque light-activated calcium hydroxide (Ca(OH)2) preparation. This allows prosthetically-driven treatment planning and surgical placement of 2 implants to support the existing mandibular denture.

Huynh-Ba, G; Alexander, P; Vargas, A; Vierra, M; Oates, TW



Antimicrobial efficacy of denture adhesives on some oral malodor-related microbes.  


The objective of the study was to determine the antimicrobial efficacy of three denture adhesives toward Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum. Adhesives used were Corega Ultra(®), Fixodent Pro Original(®) and Biotene(®) Denture Grip. For Streptococcus oralis and Streptococcus mutans, four tubes of Trypticase Soy Broth 10 mL and 1 g denture of adhesive were used. In addition four tubes of Trypticase Soy Broth 10 mL without any denture adhesive was employed as control. For Prevotella oralis and Fusobacterium nucleatum, four tubes of thioglycolate 10 mL and 1 g denture adhesive were used for each one, while four tubes of thioglycolate 10 mL without adhesive served as control. All samples were incubated for 48 h at 37°C. After 48 h, the number of colonies was counted and the mean was extracted as cfu/mL. The results were evaluated with ANOVA on ranked data and Tukey's post hoc test at ? = 0.05. Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum showed decreased number of colonies for each denture adhesive compared to the control. Under the conditions of this in vitro study, all the tested denture adhesives showed antimicrobial efficacy. However, in contrast to the hypothesis, there were differences among them. Corega Ultra(®) and Biotene(®) Denture Grip were more effective for all the tested oral malodor-related microbes than Fixodent Pro Original(®). PMID:22075753

Polyzois, Gregory; Stefaniotis, Theodoros; Papaparaskevas, Joseph; Donta, Catherine



Measuring of corneal thickness of contact lens wearers with keratoconus and keratoplasty by means of optical coherence tomography (OCT).  


To measure the corneal thickness and the depth of the precorneal tear film of contact lens wearers with keratoconus or keratoplasty and to reconfirm the identification and classification of the keratoconus with optical coherence tomography (OCT). The cornea and precorneal tear film of 123 eyes with keratoconus, of 39 eyes after keratoplasty and 8 eyes after LASIK were examined with an OCT (Zeiss Visante) and a keratograph (Oculus). Visual acuity was determined. The mean age of all patients was 42.7 years (sigma = 9). There were 35% female patients and 65% were male patients. The central corneal thickness of 123 eyes with keratoconus was 467 +/- 73 microm. The nasal and especially the inferior corneal periphery exhibit a 9% lesser thickness (426 +/- 83 microm). The cornea with keratoconus is thinner in the 90 degrees meridian, than in the 180 degrees meridian (p < 0.01). This could be a clinically relevant result for the reduction of astigmatism after keratoplastic surgery. The central corneal thickness of 39 eyes with keratoplasty was 555 +/- 65 microm. These eyes showed peripheral parts with even less thickness. The thickness of the precorneal tear film of 114 contact lens wearers with keratoconus was 89 +/- 42 microm in the horizontal meridian, 113 +/- 56 microm in the vertical meridian. All the comparative results in case of keratoconus, keratoplasty and the depth of the precorneal tear film had high statistical significance (p < 0.001). Optical coherence tomography is particularly suitable for the examination of eyes with keratoconus and keratoplasty. It delivers new insight into corneal thickness of eyes with keratoconus and keratoplasty. PMID:23837239

Pöltner, Gustav; Miller, Klaus; Berke, Andreas; Sickenberger, Wolfgang



Splinting osseointegrated implants and natural teeth in partially edentulous patients: a systematic review of the literature.  


Dental implants in partially edentulous patients are a predictable therapeutic option. In patients with reduced bone volume, tooth-to-implant connected prostheses have been described as a treatment option. In this systematic review, the incidence of biologic and technical complications and the long-term survival rates of tooth-implant supported fixed partial dentures (FPDs) are analyzed. In cases where a natural tooth is connected with an implant to support a FPD, a rigid connection should be preferred. PMID:21073343

Mamalis, Anastasios; Markopoulou, Kleopatra; Kaloumenos, Konstatinos; Analitis, Antonis



Evaluation of efficacy of commercial denture cleansing agents to reduce the fungal biofilm activity from heat polymerized denture acrylic resin: An in vitro study  

PubMed Central

Aims: To compare and evaluate Candida removing effects of three most commonly available varieties of commercial denture cleansers from heat polymerized acrylic resins. To compare and evaluate Candida lytic effects of denture cleansers. To assess the effect of time on ability of denture cleansers in reducing Candidal biofilm. Materials and Methods: A specially designed metal mold was fabricated to obtain wax plates of uniform dimensions which were used to fabricate heat cure acrylic resin plates. A square-shaped window of dimension 15 mm and thickness of 1.5 mm was provided in metal mould to simulate thickness of denture base. All samples used in this study were prepared using this mould. Candida albicans colonies were then cultured on this acrylic resin plates by colonization assay. Yeast removing test for samples was performed using microscope and yeast lytic test was performed using photo colorimeter. Results: Denture cleanser D2 showed the highest Candida removing activity when compared with cleansers D1, D3, and control solution. Denture cleansers D2 showed increased yeast lytic ability when compared with denture cleansers D1, D3, and control solution. More time span shared a definite influence on yeast lytic ability of denture cleansers. Conclusions: The effect of cleansing agents on removal of colonized yeasts particularly fungal biofilm from acrylic resins was assessed for clinical implications. The observation indicated superior performance of cleanser D2 when compared with D1 and D3 even though they all belong to same chemical group of alkaline peroxide. The increased effectiveness may be due to presence of sodium lauryl sulphate in formula of D2.

Dhamande, Mithilesh M.; Pakhan, Ashok J.; Thombare, Ram U.; Ghodpage, Shyam L.



[Mechanical analysis of the denture bases using the photoelastic-coating method. 2. Upper complete denture bases under uniform bending moment load].  


Deformation of the anterior teeth and palatal regions on upper complete dentures was investigated using the photoelastic coating method and strain gages. In this experiment, an uniform-moment bending load method was employed to simulate the occlusal situation, and the distribution of strain in epoxy resin, stainless swaged and Co-Cr alloy cast dentures were measured and analyzed. The 030-series reflection polariscope is compact and lightweight with its main components consisting of two polarizer/quarter-wave-plate assemblies attached to a common frame. The highest level of strain was seen in the anterior region of the palate and the low strain was observed in other regions. Differences in strain magnitude of the three dentures were not observed with test at the same point. But, when denture base materials with high flexural rigidity and bending strength were used on the palatal region of the denture base, strain was decreased in the anterior and other regions of the palate. Therefore, dentures using those materials could be effectively reinforced. PMID:2489596

Takayama, Y; Takakuda, K; Miyairi, H



Further observations on high impact strength denture-base materials.  


Previous studies have shown that high impact strength can be conferred on denture-base poly(methyl methacrylate) polymers by modification with acrylic-terminated butadiene-styrene block copolymers, and that the acrylic end-group was necessary for effective reinforcement. It is now shown that, by solvent extraction studies, grafting of the copolymer occurs both with acrylic-terminated and non-terminated block copolymers. It is therefore concluded that the mode of grafting is different, and some possible mechanisms are discussed. PMID:1420720

Rodford, R A; Braden, M



Development and Validation of an In Vivo Candida albicans Biofilm Denture Model?  

PubMed Central

The most common form of oral candidiasis, denture-associated stomatitis, involves biofilm growth on an oral prosthetic surface. Cells in this unique environment are equipped to withstand host defenses and survive antifungal therapy. Studies of the biofilm process on dentures have primarily been limited to in vitro models. We developed a rodent acrylic denture model and characterized the Candida albicans and mixed oral bacterial flora biofilm formation, architecture, and drug resistance in vivo, using time course quantitative culture experiments, confocal microscopy, scanning electron microscopy, and antifungal susceptibility assays. We also examined the utility of the model for measurement of C. albicans gene expression and tested the impact of a specific gene product (Bcr1p) on biofilm formation. Finally, we assessed the mucosal host response to the denture biofilm and found the mucosal histopathology to be consistent with that of acute human denture stomatitis, demonstrating fungal invasion and neutrophil infiltration. This current oral denture model mimics human denture stomatitis and should be useful for testing the impact of gene disruption on biofilm formation, studying the impact of anti-infectives, examining the biology of mixed Candida-oral bacterial flora biofilm infections, and characterizing the host immunologic response to this disease process.

Nett, Jeniel E.; Marchillo, Karen; Spiegel, Carol A.; Andes, David R.



Effectiveness of Photodynamic Therapy for the Inactivation of Candida spp. on Dentures: In Vitro Study  

PubMed Central

Abstract Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24?h. Dentures submitted to PDT (P+L+) were individually sprayed with 50?mg/L of Photogem® (PS) and, after 30?min, illuminated by LED light for 26?min (37.5?J/cm2). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48?h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05). Results: For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log10). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures.

Mima, Ewerton Garcia de Oliveira; Ribeiro, Daniela Garcia; Dovigo, Livia Nordi; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador



An investigation of complete denture teaching in the UK: part 1. A survey of undergraduate teaching.  


Aim This paper is the first in a series of two that investigate the undergraduate teaching of complete dentures in the UK.Materials and methods A questionnaire was sent by email to 13 UK dental schools enquiring about the number of hours spent in the lecture theatre, laboratory and clinic. The schools were also asked to give their views about the preparedness of the new graduates for dealing with complete dentures in general practice.Results There was great disparity between schools in the overall number of lectures delivered. Two schools claimed 28 hours and the remainder varied between 6-15 hours. Four schools devoted more time to laboratory work whereas three schools spent more time in the clinic. One school reported no dedicated clinical time for complete dentures. There appears to be a regional variation with northern UK dental schools spending more time on the teaching of complete dentures. The quota for complete dentures varied from three in most schools to eight in one school and none in another. Comments from the dental schools varied from a reported lack of suitable complete denture cases, to concerns with insufficient curricular time devoted to the subject and a subsequent lack of clinical competence on graduation. Some schools have integrated complete denture teaching into the general prosthodontic course as it is considered inappropriate to teach different aspects of prosthetics in isolation.Conclusion Competence in complete dentures falls short of what is expected. With a single exception all the schools seem to have low expectations for their undergraduate students to be practically trained and experienced in the production of complete dentures. Despite the advent of implants and the introduction of clinical dental technicians, there is and will continue to be a need for the competent treatment of the edentulous population by general practitioners. PMID:23969660

Wieder, M; Faigenblum, M; Eder, A; Louca, C



[Observations on before and after employ of screw of implant denture with SEM].  


The loss of screw is one of the clinic complication in MDIC implant denture cases. The purpose of this study is to find the cause of loss of screw. The authors has studied MDIC implant denture with SEM before and after employ of the screw and found that the causes of screw loss were crevice corrosion and friction pressure. Crevice corrosion may promote the loss of screw. Base the above condition, it is necessary to select Ti-alloy screw and associat with anticorrosive measure in MDIC implant denture construction. PMID:10677963

Song, Y; Xu, J; Ma, X



A drug-free oral hydrogel wound dressing for pain management in immediate denture patients.  


This article evaluated a drug-free oral hydrogel wound dressing composed entirely of natural food ingredients for its ability to relieve pain in immediate denture patients. Evaluation occurred at a 24-hour postoperative appointment. For this crossover study, 44 patients who were taking oral narcotics evaluated their discomfort (using a scale of 0-10) at 1, 3, 5, and 10 minutes after denture insertion with no topical treatment and again after SockIt! Oral Pain Gel was applied to the dentures. The gel provided statistically significant pain relief at all time points beyond that provided by oral narcotic alone (p < 0.0001). PMID:19903626

Kennedy, Thomas J; Hall, John E


Effect of location of glass fiber-reinforced composite reinforcement on the flexural properties of a maxillary complete denture in vitro.  


Objective. To evaluate the effect of the location of glass fiber-reinforced composite (FRC) reinforcement on the flexural load at the proportional limit (FL-PL) and the flexural deflection of a maxillary acrylic resin complete denture. Material and methods. Maxillary acrylic resin complete dentures strengthened with and without FRC reinforcement were tested. The polymerized FRC was embedded in the denture base resin in the doughy state and placed (1) under the ridge lap region, (2) in the anterior region, (3) in the middle region or (4) in the anterior and posterior regions. The FL-PL and flexural deflection value at the 100-N loading point of the reinforced maxillary denture specimens were tested. Results. All of the reinforced dentures had a higher FL-PL than the denture without reinforcement but the FL-PL values of all the dentures were not significantly different from each other. The efficiency of the FRC reinforcement compared to the unreinforced denture was 1.54-1.75 times greater. All of the reinforced dentures showed significantly lower deflection compared to the unreinforced denture, but the flexural deflections of all the dentures were not significantly different from each other. Conclusions. The location of the FRC reinforcement did not affect the fracture resistance of the maxillary acrylic resin complete denture. All of the reinforced dentures had higher FL-PL and lower flexural deflection than the denture without reinforcement. PMID:21281056

Takahashi, Yutaka; Yoshida, Kaneyoshi; Shimizu, Hiroshi



The association between socioeconomic status, oral hygiene practice, denture stomatitis and oral status in elderly people living different residential homes.  


Oral hygiene practices and denture status of elderly people living in residential homes are different depending on the type of residential homes. In this study the elderly people living in three different residential homes were investigated for this purpose. A total of 269 subjects, 119 males (mean age 73.9±8.8) and 150 females (mean age 78.5±7.2) were involved in this study. All subjects were interviewed and clinically examined. Age, sex, educational status, financial status, general health, dental visiting, overnight denture wearing, brushing habits and frequency were recorded using a structured questionnaire. The prevalence of edentulism, the presence and type of dental prostheses, denture cleanliness and the presence of denture stomatitis were evaluated. Forty-one percent of subjects were non-educated. Fifty-one percent of subjects had low income. The majority of people (66.6%) were edentulous. Among the edentulous subjects 32% had full denture and 16% had no denture. Forty three percent of the subjects reported cleaning their dentures with water and 40% with a toothbrush only. Denture hygiene was good for 14% of the subjects. Denture stomatitis was observed in 44% of the subjects wearing dentures. There was statistically significant difference between residential homes and educational status, level of income, dental visiting, denture status, brushing methods and brushing frequency (p<0.001). A positive relationship was observed between poor denture hygiene habits and the presence of denture-related stomatitis. The most important need within the residents of the residential home was the enhancement of oral care social insurance. PMID:21269712

Evren, Buket Akalin; Uludamar, Altay; I?eri, Ufuk; Ozkan, Yasemin Kulak



Ricinus communis treatment of denture stomatitis in institutionalised elderly.  


This study compared the effectiveness of Ricinus communis (RC) with Nystatin (NYS) and Miconazole (MIC) in the treatment of institutionalised elderly with denture stomatitis (DS). They (n = 30) were randomly distributed into three groups: MIC, NYS or RC. Clinical and mycological evaluations were performed prior to the use of the antifungal (baseline) and repeated after 15 and 30 days of treatment. The sample was clinically examined for oral mucosal conditions. Standard photographs were taken of the palate, and the oral candidiasis was classified (Newton's criteria). Mycological investigation was performed by swabbing the palatal mucosa, and Candida spp. were quantified by counting the number of colony-forming units (cfu mL?¹). The clinical and mycological data were analysed, respectively by Wilcoxon and Student's t-test (? = 0.05). Significant improvement in the clinical appearance of DS in the MIC and RC groups was observed between the 1st and 3rd collections (MIC - P = 0.018; RC - P = 0.011) as well as between the 2nd and 3rd collections (MIC - P = 0.018; RC - P = 0.011). Neither groups showed a statistically significant reduction in cfu mL?¹ at any time. Although none of the treatments decreased the cfu mL?¹, it was concluded that Ricinus communis can improve the clinical condition of denture stomatitis in institutionalised elderly patients, showing similar results to Miconazole. PMID:23438045

Pinelli, L A P; Montandon, A A B; Corbi, S C T; Moraes, T A; Fais, L M G



Biocompatibility of visible light-polymerized denture base resins.  


The biocompatibility of three commercial formulations of visible light-polymerized denture base resins was studied to determine its effects on the RNA and DNA synthesis of oral epithelial cells in vitro. Isotope incorporation into RNA or DNA was measured after 24 hours of incubation with isotope and 48 hours of exposure to resin. The resins were shown to significantly inhibit the synthesis of both nucleotides as compared to a heat-processed resin control. Increasing the polymerization time can mitigate the toxicity of some of the resins. The air barrier coatings used to prevent oxygen inhibition of polymerization increased the toxic effects of two resins and decreased that of one of the materials. These investigations suggest that visible light-polymerized denture resins may impair the replication of oral epithelial cells. DNA synthesis is more sensitive to the toxic effects of the materials, which may relate to the ability to cause mucosal pathology. The cytotoxic effects may relate to the presence of unpolymerized resin constituents or polymerization by-products. PMID:7507674

Barron, D J; Schuster, G S; Caughman, G B; Lefebvre, C A


Acanthamoeba keratitis due to genotype T11 in a rigid gas permeable contact lens wearer in Spain.  


A case of a 59-year-old Spanish patient who presented with severe ocular pain, blurred vision, eyelid swelling and foreign body sensation in the right eye is reported. She was a regular gas permeable contact lens [corrected] wearer who initially claimed to maintain standard lens care. After exploration, conjunctival injection, dendritiform corneal ulcers and stromal edema were observed. She was initially treated for a possible viral keratitis due to herpes simplex virus using 3% topical acyclovir and 0.1% dexamethasone eye drops 5 times a day. The patient did not respond to this treatment and six weeks later, corneal scrapings were positive for Acanthamoeba genotype T11. She was then treated with chlorhexidine 0.02%, propamidine 0.1% and 1% cycloplegic eye drops hourly which resulted in a significant improvement. After a month, ocular pain decreased and the clinical signs of keratitis ameliorated observed as a diminution of the size of the ulcer and also in the extension and opacity of the corneal infiltrates. The patient has been following this treatment for 3 months and it is possible that she will have to carry on with it for a whole year. To the best of our knowledge, this is the first case of severe keratitis due to Acanthamoeba genotype T11 in Spain . PMID:21130679

Lorenzo-Morales, Jacob; Morcillo-Laiz, Rafael; Martín-Navarro, Carmen Ma; López-Vélez, Rogelio; López-Arencibia, Atteneri; Arnalich-Montiel, Francisco; Maciver, Sutherland K; Valladares, Basilio; Martínez-Carretero, Enrique



[Partial tonsillectomy].  


The feasibility of partial tonsillectomy was reviewed. Compared with total tonsillectomy, partial tonsillectomy has the advantages of less postoperative pain, lower postoperative bleeding rate and faster recovery. Partial tonsillectomy has a potential for tonsil regrowth and its efficacy in treating sleep-disordered breathing in children is still controversial. PMID:24015642

Guo, Pengfei; Li, Jinrang



Leaching and cytotoxicity of formaldehyde and methyl methacrylate from acrylic resin denture base materials.  


Acrylic resin dentures have the potential to elicit irritation, inflammation, and an allergic response of the oral mucosa. Studies of substances leachable from acrylic resins, their cytotoxicity to cultured cells, and means of reducing their leaching were systematically conducted. Under in vivo and in vitro conditions, formaldehyde and methyl methacrylate were significantly leached into human saliva and saliva-substitute buffer, especially from autopolymerized resins. Both leachable substances showed cytotoxic potentials in the range of their leaching concentrations. Formaldehyde was cytotoxic at lower concentrations than methyl methacrylate. Preleaching in water reduced subsequent leaching of both formaldehyde and methyl methacrylate, and the amount of reduction depended on an increase in the preleaching temperatures. Immersion of acrylic resin dentures in hot water (50 degrees C) before insertion is recommended, especially for autopolymerized resins used either for rebasing or as denture base materials, to minimize the risk of adverse reactions in patients who wear acrylic resin dentures. PMID:8040827

Tsuchiya, H; Hoshino, Y; Tajima, K; Takagi, N



21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification....



Bond of acrylic teeth to different denture base resins after various surface-conditioning methods.  


The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin. PMID:21181215

Lang, Reinhold; Kolbeck, Carola; Bergmann, Rainer; Handel, Gerhard; Rosentritt, Martin



Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion  

PubMed Central

PURPOSE This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm × 25 mm × 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 µm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (?=.05). RESULTS Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9±0.4 - 5.58±0.6 MPa) compared to the control (3.64±0.5 - 4.58±0.5 MPa) and air-abraded groups (3.1±0.6 - 4.46±0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1±0.6 MPa). CONCLUSION Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.

Bagis, Bora; Ozcan, Mutlu; Durkan, Rukiye; Turgut, Sedanur; Ates, Sabit Melih



A simple and inexpensive bar-coding technique for denture identification  

PubMed Central

A number of commercial methods for identifying dentures are available. They can be either invasive or noninvasive techniques. The less sophisticated procedures include simple engraving with bur, and more sophisticated procedures use labels or chips. Bar coding system is a way of transferring data to the computer and huge data can be stored as a record. Bar coding can be easily incorporated during acrylization of the denture and thus could be used in individual identification.

Nalawade, Sonali N; Lagdive, Sanjay B; Gangadhar, SA; Bhandari, Aruna J



Fabrication of a caliper device for interalveolar dimension measurement in the complete denture patient.  


A method is presented for measuring interalveolar dimension (IAD) of existing dentures using a caliper. Directions for construction of an IAD gauge are included. This device is easy to construct and "zeroes out" in the closed position. The measurement is useful for determining occlusal vertical dimension (OVD) in new dentures and for monitoring changes over time. Its dimension is entered in the patient record for future reference. PMID:18544134

Pitigoi-Aron, Gabriela; Labarre, Eugene; Giusti, Lola; Leknius, Casimir



A simple and inexpensive bar-coding technique for denture identification.  


A number of commercial methods for identifying dentures are available. They can be either invasive or noninvasive techniques. The less sophisticated procedures include simple engraving with bur, and more sophisticated procedures use labels or chips. Bar coding system is a way of transferring data to the computer and huge data can be stored as a record. Bar coding can be easily incorporated during acrylization of the denture and thus could be used in individual identification. PMID:22408329

Nalawade, Sonali N; Lagdive, Sanjay B; Gangadhar, Sa; Bhandari, Aruna J



Curricula for the teaching of complete dentures in Spanish and Portuguese dental schools  

PubMed Central

Objectives: Given the need to ensure that dentists are sufficiently skilled to offer the best possible care to their patients, this study aims to evaluate the teaching methods and clinical experience achieved by undergraduate dental students in Spain and Portugal as regards complete dentures. Study design: In February 2011, a questionnaire seeking information about the preclinical and clinical teaching of complete dentures was e-mailed to all Spanish and Portuguese dental schools with fully developed undergraduate degree dental programs. Results: A response rate of 82.6% was obtained. The distribution of lectures and hours spent at the laboratory and in clinical activities revealed that teaching complete dentures is eminently a practical issue, this being mostly performed by full-time prosthodontists. All surveyed schools teach the design of the record base, and most of them instruct students in the mounting of teeth in wax. Most schools (94.7%) used a semiadjustable articulator, alginate for primary impressions (73.7%) and elastomeric materials in border-molded custom trays for final impressions (68.4%). In most schools, within the clinical setting students work in pairs, the mean student/ professional staff member ratio being 2.3 ± 0.7. Most schools perform a competence-based assessment (83.3%), although innovative techniques such as problem-based learning are still rarely applied. On average, the students emplaced 1.8 ± 1.2 complete dentures during their clinical training, ranging from 0 to 4, although no clear trend was seen as regards the minimum number of dentures to be made for graduating. Conclusions: Variations in teaching programs and clinical experience concerning complete denture curricula among Spanish and Portuguese dental schools are evident, but all the schools base their teaching mainly on preclinical and clinical practice. However, the low number of dentures made by student per year seems insufficient to ensure clinical skills and cope with social needs. Key words:Dental education, questionnaires, complete dentures, curricula.

Castillo-de Oyague, Raquel; Albaladejo, Alberto



The effect of aluminium on the metallography of a nickel base removable partial denture casting alloy.  


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. PMID:285671

Lewis, A J



The effect of carbon on the metallography of a nickel base removable partial denture casting alloy.  


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. PMID:288385

Lewis, A J



Pattern waxes and inaccuracies in fixed and removable partial denture castings.  


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. PMID:9151279

Diwan, R; Talic, Y; Omar, N; Sadig, W



A study on the fracture strength of collarless metal-ceramic fixed partial dentures  

PubMed Central

PURPOSE The objective of this study was to evaluate fracture strength of collarless metal-ceramic FPDs according to their metal coping designs. MATERIALS AND METHODS Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Fifteen 3-unit collarless metal-ceramic FPDs were fabricated in each group. Finished FPDs were cemented to PBT (Polybutylene terephthalate) dies with resin cement. The fracture strength test was carried out using universal testing machine (Instron 4465, Instron Co., Norwood MA, USA) at a cross head speed of 0.5 mm/min. Aluminum foil folded to about 1 mm of thickness was inserted between the plunger tip and the incisal edge of the pontic. Vertical load was applied until catastrophic porcelain fracture occurred. RESULTS The greater the bulk of unsupported facial shoulder porcelain was, the lower the fracture strength became. However, there were no significant differences between experimental groups (P > .05). CONCLUSION All groups of collarless metal-ceramic FPDs had higher fracture strength than maximum incisive biting force. Modified collarless metal-ceramic FPD can be an alternative to all-ceramic FPDs in clinical situations.

Yoon, Jong-Wook; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk



Rehabilitation of lost vertical dimension with cast post core and cast partial denture.  


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

Gupta, Kavita; Javiya, Piyush; Kumar, Prachur; Mallikarjuna, Rachappa



Three-month change in the radiodensity of alveolar bone supporting partial-denture abutment teeth.  


This study uses the intraoral microdensitometric method to examine the impact of masticatory pressure on the alveolar bone around the abutment teeth clasp. Two retroalveolar radiographs were carried out on all 30 subjects over a period of 3 months using a copper calibration stepwedge. The dental radiographs were digitized and converted into positive. Grey level values on dental radiographs in the alveolar bone area in 7 region of interest (ROI) were measured. They were converted into the equivalent thickness of the calibration stepwedge using mathematical methods and the difference of the bone density between the two radiographs was calculated. The results demonstrated that there were no statistically significant differences between the 1st and 2nd radiographs in any of ROI (p > 0.05). PMID:12674851

Kovacevi?, D; Deli?, Z; Celebi?, A; Kovac, Z; Grzi?, R; Uhac, I; Zlatari?, D Knezovic



Management of fractured implant case using loop connector fixed partial denture.  


Dental implants treatment have become a common modality of treatment nowadays for the replacement of missing tooth/teeth, but there have been failures due to a number of reasons; one of the rare problems is the fracture of the dental implants fixture. It is of prime importance to understand the type/system of the implant to be placed in a site and the amount and direction of occlusal forces incurred after the loading of prosthesis. PMID:23709559

Yadav, Ashish; Gupta, Aratee; Tandan, Amrit; Kumar, Sulabh



A feasibility study on laser rapid forming of a complete titanium denture base plate.  


This work attempted to integrate the technologies of computer-aided design and computer-aided manufacture (CAD/CAM) and laser rapid forming (LRF) for the fabrication of the titanium plate of a complete denture. By the combination of laser scan and reverse engineering software, the standard triangulation language (STL)-formatted denture base plate was finally designed and sliced into a sequence of numerical controlled codes. The titanium (Ti) complete denture plate was finally built, layer-by-layer, on the LRF system. To evaluate the quality of fit, a virtual adaptation test that measured and compared the profiles of the laser free formed denture plate and those of the edentulous plaster cast had been conducted, and the mean deviation was found to be 0.34 mm. After traditional dental finishing techniques, a complete denture with a Ti base plate was then made and judged to be acceptable. The CAD/CAM/LRF system is a potential candidate and a new platform for the design and manufacture of custom-made Ti denture plates and restorations. PMID:18716825

Wu, Jiang; Gao, Bo; Tan, Hua; Chen, Jing; Tang, Chak-Yin; Tsui, Chi-Pong



Dissolution of cast aluminum in different denture cleansers.  


Aluminum is one type of metal base material used as an alternative to acrylic resin. This study evaluated whether commonly used denture cleansers cause leaching of the metal base into the cleaning solution. Seven cleansers (Efferdent, Polident, Clorox, Clorox/Cascade, vinegar, Tartar and Stain Remover, and Ivory soap) and two controls (tap water and distilled water) were evaluated. One hundred thirty-five wax samples (30 x 30 x 1 mm) were cast in 99.4% pure aluminum. The 135 samples were randomly assigned to the nine cleanser groups. Each sample was soaked in a cleanser for 0.5, 1, or 8 hours, and the amount of aluminum present in each cleanser was then analyzed by atomic flame-emission spectrometry. The results indicated that all cleansers leached aluminum into solution in varying amounts. Tartar and Stain Remover and Clorox caused the greatest leaching, whereas Ivory soap and Efferdent leached the least. PMID:7916895

Sindel, D W; Billy, E J; Richards, M W; Rains, T C; Li, S H


Electromyographic Activity of the Mandible Muscles at the Beginning and End of Masticatory Cycles in Patients with Complete Dentures  

Microsoft Academic Search

The aim of this study was to assess the electrical activity of the masseter and anterior temporal muscles in subjects with severe bone resorption at two different times: (a) the initial period, with the complete dentures they had worn for over 10 years, and (b) the final period, 5 months after having new dentures put into place. Twelve asymptomatic subjects

Marcelo Coelho Goiato; Alício Rosalino Garcia; Daniela Micheline dos Santos



Implant overdentures: dental students' performance in fabrication, denture quality, and patient satisfaction.  


The purpose of this study was to evaluate dental students' performance when fabricating a mandibular two-implant overdenture (OD) as compared to conventional dentures (CD) and to determine if these prostheses were successful. Twenty students and twenty patients were divided into two groups: complete denture group (CDG) and maxillary denture and two-implant OD group (ODG). Students' progress was evaluated at each appointment as they were given a clinical assessment score (CAS), which varied from 1 (unacceptable, needs to repeat procedure) to 4 (acceptable, no errors). The success of the prosthesis was evaluated by the patients using a visual analog scale (VAS) and an expert (a prosthodontist) using a denture quality assessment (DQA) form. Performance for both groups was not statistically different across all eight appointments (CDG 3.16 versus ODG 3.25; p=0.46). Patients with ODs reported greater stability with their dentures (p=0.048) and greater ability to chew than patients with CDs (p=0.03). There were no differences between the groups in terms of expert appraisal (ODG 71.1 versus CDG 67.5; p=0.59). The performance of dental students when fabricating a two-implant OD is thus not different from that of a CD. Students can successfully fabricate a two-implant OD as perceived by both patients and prosthodontists. PMID:20837741

Aragon, Cecilia E; Cornacchio, Angelica Lee Petrina; Ibarra, Lilia Marcela; Saad, Muhammed N; Zibrowski, Elaine



Physical Properties of Denture Base Resins Potentially Resistant to Candida Adhesion  

PubMed Central

Purpose The addition of anionic charge on denture base resins has been shown to inhibit Candida albicans adhesion and to facilitate adsorption of salivary defense molecules. The aim of this study was to evaluate the physical properties of a modified denture base resin for denture fabrication. Materials and Methods Specimens made from heat polymerizing resin Lucitone 199 were used as the control group. The two experimental groups, E-10 and E-20, had 10% and 20%, respectively, of the monomer substituted with an experimental phosphate-containing monomer. Flexural strength and modulus, water sorption, solubility, and color stability tests were conducted to ensure compliance with ADA specification No. 12. Water diffusion coefficient into the resins and stainability were also assessed. ANOVA and Scheffe tests were performed for statistical significance. Results There was an overall decline in all properties with the addition of the experimental phosphate compound. The flexural strength and modulus, water sorption and solubility for E-10, as well as the control were, however, within the ADA specifications. The diffusion coefficients were significantly different (p < 0.05) for the three groups. Staining and color specimens showed no significant difference (p > 0.05) among the three groups. Conclusions Within the limitations of this study, the physical properties of the phosphate denture base resin at 10% should be suitable for denture fabrication based on the properties assessed.

Dhir, Gunjan; Berzins, David W.; Dhuru, Virendra B.; Periathamby, A. Raj; Dentino, Andrew



[Application of microwave for dental technique. 5. Injection molding system for resin base denture].  


An injector and FRP denture flask were developed for injection molding and the fit of the denture base constructed with this injection molding system was evaluated. In addition, the flow and pressure of the dough, that is polymer-monomer mixture, in the mold space were investigated. The monomer of 10 mg/cm2 in the dough vaporized during the 5 minutes it took for the flash to be removed. When pressure of more than 55 kgf/cm2 was exerted to the dough, the dough was completely packed in the mold space. Fastening of the sprue with a bolt within 2 minutes after injection of the dough made the pressure of the dough increase to about 30 kgf/cm2. The dough in the mold space was maintained at a pressure of above 20 kgf/cm2 for microwave heating time. The adaptability of the resin base denture constructed with a combination of injection molding and microwave polymerization was 2 or 3 times greater than that of the denture constructed with microwave heating from the tissue side of the denture base. PMID:2134815

Kimura, H; Teraoka, F; Sugita, M



[Studies on the thinning of the upper acrylic resin complete denture with the reinforced palate. (Part 1). Thinning of the resin denture base with the standard shape (author's transl)].  


The acrylic denture bases are most commonly used as compared with metallic denture bases at present. For this reason, it is due to many excellent properties, for example, simple processing, easy repair, cheapness and so on. But an inherent disadvantage is liability of an acrylic denture base to make thick so as to maintain stiffness and strength and it makes patients uncomfortable. Therefore, the purpose of this paper is to make the palatal region of the upper complete denture thin with about 0.7 mm in thickness, and to keep the same mechanical properties as the normal resin dentures using the composites materials with carbon cloth. Tensils test of the plate test-piece and uniform bending test of the upper complete denture with steel wings were respectively performed. The results obtained in this investigation are as follows: 1) The acrylic composites reinforced with carbon cloth have shown the superior mechanical properties to be compared with the acrylic resin to be generally used. 2) The thickness of the reinforced thin denture is decreased to 0.7 mm (its thickness is 60% of the normal thickness of the one), nevertheless, the stiffness and strength are increased with the using of the composite materials. 3) The region of highest surface tensile stress in the denture was on the polished surface of the palatal aspect of the denture in the area immediately behind the anteriors, but at this region, the strain of the reinforced thin denture base decreased its strain 10% in comparison with the non-reinforced normal thick one. PMID:293365

Takayama, Y



Effect of polymerization techniques on vertical dimension and tooth position in complete dentures.  


Due to the changes in the composition and processing of acrylic resins, it seems appropriate to evaluate the influence of polymerization methods about the alteration of occlusal vertical dimension and the horizontal positioning of artificial teeth of total dentures. For this, 64 specimens were made, simulating a maxillary total denture waxed from a standard maxillary denture. The experimental samples were divided into two groups: Group 1 - The resins were submitted to polymerization in a hot water bath, Group 2 - The same resins were submitted to poly-merization by microwave energy. The samples were measured horizontally and vertically before and after the polymerization process. Based on the results, it can be concluded that there was no statistically significant difference between the conventional polymerization method and the polymerization method by microwave, related to the stability of occlusal vertical dimension and horizontal positioning of artificial teeth on the specimens evaluated. PMID:22165322

Slaviero, Thiago V S; Simon, Gabriel H P; Tagliari, Ivânio; Busato, Priscila M R; Sinhoreti, Mario A C; Camilotti, Veridiana; Mendonça, Marcio J



Comparison of denture base resin reinforced with polyaromatic polyamide fibers of different orientations.  


The aim of this study was to evaluate the effect of reinforcing polyaromatic polyamide (aramid) fibers with various orientations on the flexural properties of denture base resin. Aramid fibers with four orientations of unidirectional, woven, non-woven and paper-type were pre-impregnated and placed at the bottom of a specimen mold. Heat-polymerized denture base resin was packed over the fibers and polymerized. A three-point bending test was performed using a universal testing machine at a crosshead speed of 5 mm/min. The flexural strengths and flexural moduli of the unidirectional and woven groups were significantly higher than those of the control and other experimental groups.For the flexural moduli, all experimental groups showed significantly higher reinforcing effects than the control group. In conclusion, the unidirectional group located perpendicular to the direction of the load was most effective in reinforcing the denture base resin, followed by the woven group. PMID:23538771

Yu, Sang-Hui; Ahn, Dae-Hyung; Park, Ji-Su; Chung, Yong Sik; Han, In-Sik; Lim, Jung-Seop; Oh, Seunghan; Oda, Yutaka; Bae, Ji-Myung



Impact strength of acrylic denture base resin reinforced with woven glass fiber.  


This study investigated the effect of the number and position of woven glass fibers in denture base resin matrix on its impact strength. Test specimens were reinforced with woven glass fiber 0.5, 1.0, or 1.5 mm below the surface. The impact strength was tested using an Izod-type impact tester with an impact speed of 335 cm/s, which simulates dropping the denture, and using a flywheel-type impact tester with a two-point support at 13.5 and 75.0 cm/s, which simulates the chewing. The woven glass fibers had a strengthening effect in all tests, and the impact resistance was further improved when the woven glass fibers were positioned more superficially in the resin. The results suggest that woven glass fiber is an effective reinforcement in denture base resin. PMID:12790294

Kanie, Takahito; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji



Water sorption, solubility and dimensional changes of denture base polymers reinforced with short glass fibers.  


The aim of this study was to determine water sorption, solubility and dimensional stability of injection and compression-molded polymethyl methacrylate based denture base polymer that was reinforced with various concentrations and lengths of E-glass fibers. For water sorption and solubility, 20 test groups with different fiber contents and lengths of fibers were prepared. Test specimens without fibers were used as a control. The water sorption and solubility was measured after 90 days water storage. For dimensional stability, rhombic test specimens were prepared and the dimensional changes were measured after processing, drying and storing in water for 4 days and 30 days and were compared with those on the brass model. The water sorption and solubility of injection-molded denture base polymer was lower compared to compression-molded specimens (p < 0.05). The dimensional accuracy of denture base polymer was not affected with fiber reinforcement (p > 0.05). PMID:12797423

Polat, Tülin N; Karacaer, Ozgül; Tezvergil, Arzu; Lassila, Lippo V J; Vallittu, Pekka K



[Transverse strength and acoustic emission characteristics of commercial denture base resins].  


Transverse strength and acoustic emission (AE) characteristics were measured by the transverse test in deionized water at 37 degrees C on commercial denture base resins (five heat-cured type resins and one polysulfone). Difference in flexural property of five heat-cured denture base resins was not shown from the transverse deflection according to JIS, but high toughness of polysulfone was recognized in transverse deflection, flexural strength, flexural modulus, flexural rigidity, flexural proof stress, and fracture energy. The five heat-cured denture base resins showed a low AE activity, but the polysulfone resin high AE activity. Significant rates of AE for polysulfone were detected at a kgf of approximately 50-60% the maximum load. The presence of Kaiser effect in its cycle transverse test was confirmed. PMID:2135527

Kondo, S; Ohkawa, S; Hanawa, T; Sugawara, T; Ota, M



The future of complete dentures in oral rehabilitation. A critical review.  


Based on available investigations and current trends in oral rehabilitation published in the dental literature, an attempt is made to describe the possible future role of complete dentures. For edentulous patients, complete dentures have for long been the only prosthodontic treatment option. Whereas a large number of edentulous patients report satisfaction with denture usage, a smaller number are unable to adapt; for such patients, sophistication of clinical and technical processes or quality of denture-supporting tissues, appear to have little influence on patient-perceived outcomes. Since the 1980s, osseointegrated dental implants have dramatically improved the therapeutic possibilities, especially so for maladaptive patients. Those able to access such treatment can expect significant improvements in oral functional status and quality of life. While there is a downward trend in edentulism in several countries, it is region-specific, confirming the overriding influence of socio-economic factors on health status. In most societies, despite ageing populations, the need for complete dentures is not likely to reduce in the near future. Whereas a two- or even a one-implant overdenture for the edentulous mandible is increasingly regarded as a minimum standard of care in many developed countries, its routine prescription for the majority in the world who are disadvantaged is unrealistic; for them, even 'low-tech' therapies like conventional dentures are beyond their reach. Improving the conventional management of edentulous patients is a necessity and requires a keener focus by researchers, educators and clinicians in the developed world on the needs of populations with fewer resources. PMID:20002536

Carlsson, G E; Omar, R



Hinged and sectional complete dentures for restricted mouth opening: A case report and review.  


Restricted mouth opening is a definite prosthodontic hindrance to carry out treatment successfully. Restricted mouth opening can be due to many reasons such as microstomia, oral submucous fibrosis, some genetic disorder, and as a result of some surgical treatment. In the past, various techniques for prosthetic rehabilitation of limited oral opening have been tried such as surgeries, use of dynamic opening devices, magnetic devices, and modification of denture design. Here we present; a simplified technique and simple design for fabrication of maxillary hinged and mandibular hinged and sectional complete denture for a patient with restricted mouth opening due to oral submucous fibrosis. PMID:23853457

Sharma, Aditi; Arora, Pallak; Wazir, Sartaj Singh



[Influences of remelting on physical properties of denture base metal alloys].  


This research was designed in order to evaluate the mechanical properties, such as tensile strength, compressive strength, surface hardness and the elongation and reduction percentages of the length, of the metal specimens prepared from first, second and third generation castings of a denture base metal. The results revealed only a proportional decrease on surface hardnesses of the specimens casted from first, second and third meltings. While the other properties of all specimens had showed no significant differences between themselves, it was concluded that the denture base metals could be melted and used again at least three times. PMID:2637020

Türköz, Y



CAD/CAM complete dentures: a review of two commercial fabrication systems.  


The use of computer-aided design and computer-aided manufacturing (CAD/CAM) has become available for complete dentures through the AvaDent and Dentca systems. AvaDent uses laser scanning and computer technology. Teeth are arranged and bases formed using proprietary software.The bases are milled from prepolymerized pucks of resin. Dentca uses computer software to produce virtual maxillary and mandibular edentulous ridges, arrange the teeth and form bases. The dentures are fabricated using a conventional processing technique. PMID:23875432

Kattadiyil, Mathew T; Goodacre, Charles J; Baba, Nadim Z



[Microbiological validation of the choice of basic plastic for removable dentures].  


Adhesion of obligate and facultative anaerobic bacteria, favoring the development of oral inflammatory diseases, including the cariesogenic and periodontogenic bacteria and Candida albicans fungi, isolated from patients with periodontitis, to 13 basic materials used in removable denture making, was studied. The adhesion of all bacteria (Streptococcus sanguis, Prevotella melangogenica, Fusobacterium nucleatum, Corynebacterium xerosis) and fungi to hot polymerization basic materials was the maximum. The most perspective basic plastic for clinical use (preserving intact oral microbiocenosis and preventing stomatitis induced by denture wearing) are cold polymerization materials, such as Redont-03, Dentoplast Breden, Leocryl, and UHF polymerization materials Acron GC, AKR-MV, and Etakril-02. PMID:12224327

Aputiunov, S D; Ibragimov, T I; Tsarev, V N; Lebedenko, I Iu; Savkina, N I; Trefilov, A G; Arutiunov, A S; Klimashin, Iu I



Partial priapism.  


With only 34 prior cases in world literature, partial priapism (PP), also called partial segmental thrombosis of the corpus cavernosum, is a rare urological condition. The aetiology and treatment of PP is still unclear, but bicycle riding, trauma, drug usage, sexual intercourse, haematological diseases and ?-blockers have been associated with PP. In this case report and world literature review, we describe the case of a 50-year-old man suffering from PP after ingesting 100 mg of sildenafil. The patient was treated with a surgical incision for corpus cavernosum and clot evacuation, as a conservative treatment of PP was not feasible due to severe pain and unresponsiveness to analgesics. PMID:23933863

Hoyerup, Peter; Azawi, Nessn Htum



Color degradation of acrylic resin denture teeth as a function of liquid diet: ultraviolet-visible reflection analysis.  


ABSTRACT. The effect of different beverages on acrylic resin denture teeth color degradation is evaluated. Ten acrylic resin denture teeth brands were evaluated: Art Plus (AP), Biolux (BX), Biotone IPN (BI), Magister (MG), Mondial 6 (MD), Premium 6 (PR), SR Vivodent PE (SR), Trilux (TR), Trubyte Biotone (TB), and Vipi Dent Plus (VP). Teeth were immersed in staining solutions (coffee, cola, and orange juice) or artificial saliva (control) (n=6) for 1, 7, 15, or 30 days. Specimen colors were evaluated spectrophotometrically based on the Commission Internationale d'Eclairage L*a*b* system. Color differences (?E) were calculated between the baseline and post-staining results. Data were evaluated by analysis of variance and Tukey test (?=0.05). BI (1.82±0.95) and TR (1.78±0.72) teeth exhibited the greatest ?E values, while BX (0.88±0.43) and MD (1.09±0.44) teeth were the lowest, regardless of solution and measurement period, and were different from BI and TR teeth (P<0.05). Cola and coffee promoted higher denture teeth color alterations than orange juice and saliva (P<0.05). Saliva generated the lowest denture teeth color alterations. Greater immersion times caused higher denture teeth color changes. The lifespan of removable dentures and the aesthetic satisfaction of several edentulous patients may be increased with the use of stain-resistant artificial denture teeth. PMID:24126696

Hipólito, Ana Carolina; Barão, Valentim A; Faverani, Leonardo P; Ferreira, Mayara B; Assunção, Wirley G



Studies on the effects of the spillway on the occlusal table of complete dentures upon the bearing of masticatory force.  


We studied the effect of spillways in the posterior artificial teeth of complete dentures in reducing masticatory pressure on the basal mucosa by making completely edentulous patients masticate food. Using two kinds of experimental dentures, one with spillways on the occlusal table and the other without, five subjects wearing complete dentures were instructed to masticate four different types of test food. The results showed that the mastication time and the number of masticatory strokes were not much affected by the existence of spillways. However, the masticatory force of artificial teeth with spillways was slightly smaller than that of artificial teeth without spillways. PMID:9566124

Watanabe, K; Mizokami, T



Cross-contamination in the dental laboratory through the polishing procedure of complete dentures.  


Polishing of dental prostheses can cause a dangerous cycle of cross-contamination involving dentists, laboratory technicians, patients and auxiliary personnel. The aim of this study was to show the microbial contamination in the dental laboratory during the polishing procedure of complete dentures. For this purpose, 4 experiments were conducted. Experiment I -- Determination of the total colony-forming units (CFU) counts contaminating complete maxillary dentures. During the polishing procedure, determination of the CFU counts transferred to the operator (Experiment II) and of the total CFU counts transferred to previously sterilized complete dentures (Experiment III). Experiment IV -- The total counts of remaining CFU in the lathe spindle after Experiments II and III. Complete dentures were highly contaminated (mean = 1.4 x 10(7) CFU/mL). There was a elevated level of contamination by splatter and aerosols. There was high microbial transfer from the contaminated lathe spindle to the sterile prostheses (mean = 1.7 x 10(7) CFU/mL). The spindles were highly contaminated after polishing procedures (mean = 3.5 x 10(8) CFU/mL). The polishing of dental prostheses is a possible source of transmission of communicable diseases in the laboratory and requires improved techniques for infection control. PMID:15776197

Agostinho, Alessandra Marçal; Miyoshi, Paula Regina; Gnoatto, Nelson; Paranhos, Helena de Freitas Oliveira; Figueiredo, Luciene Cristina de; Salvador, Sérgio Luiz



Adhesion of oral Candida albicans isolates to denture acrylic following limited exposure to antifungal agents.  


Candidal adherence to denture acrylic surfaces is implicated as the first step in the pathogenesis of Candida-associated denture stomatitis, the most prevalent form of oral candidosis in the West. This condition is treated by topically administered antifungal agents, mainly belonging to the polyenes and azoles. As the intraoral concentrations of antifungals fluctuate considerably due to the dynamics of the oral environment, the effect of short exposure to sublethal concentrations of antifungals on the adhesion of Candida albicans to denture acrylic surfaces was investigated. Seven oral C. albicans isolates were exposed to four-eight times minimum inhibitory concentrations (MIC) of five antifungal drugs, nystatin, amphotericin B, 5-fluorocytosine, ketoconazole and fluconazole, for 1 h. After removing the drug (by repeated washing) the adhesion of these isolates to acrylic strips was assessed by an in vitro adhesion assay. Exposure to antifungal agents significantly reduced the adherence of all seven C. albicans isolates to denture acrylic. The mean percentage reductions of adhesion after limited exposure to nystatin, amphotericin B, 5-fluorocytosine, ketoconazole and fluconazole were 86.48, 90.85, 66.72, 65.88 and 47.42%, respectively. These findings indicate that subtherapeutic doses of antifungals may modulate oral candidal colonization. Further, these results may have an important bearing on dosage regimens currently employed in treating oral candidosis. PMID:9877331

Ellepola, A N; Samaranayake, L P



Physical property comparison of 11 soft denture lining materials as a function of accelerated aging.  


Soft denture-lining materials are an important treatment option for patients who have chronic soreness associated with dental prostheses. Three distinctly different types of materials are generally used. These are plasticized polymers or copolymers, silicones, or polyphosphazene fluoroelastomer. The acceptance of these materials by patients and dentists is variable. The objective of this study is to compare the tensile strength, percent elongation, hardness, tear strength, and tear energy of eight plasticized polymers or copolymers, two silicones, and one polyphosphazene fluoroelastomer. Tests were run at 24 hours after specimen preparation and repeated after 900 hours of accelerated aging in a Weather-Ometer device. The data indicated a wide range of physical properties for soft denture-lining materials and showed that accelerated aging dramatically affected the physical and mechanical properties of many of the elastomers. No soft denture liner proved to be superior to all others. The data obtained should provide clinicians with useful information for selecting soft denture lining materials for patients. PMID:8455156

Dootz, E R; Koran, A; Craig, R G



Dynamic viscoelastic properties of processed soft denture liners: Part II--Effect of aging.  


The proper functioning of soft denture liners depends to a great extent on their mechanical properties. As with many polymers these materials are affected by aging. Twelve soft denture liners were processed by a laboratory according to the manufacturers' directions. Five specimens of each material were tested without aging. Five additional specimens of each material were subjected to 900 hours of accelerated aging in a Weather-Ometer instrument. These were tested with a dynamic viscoelastometer at three frequencies and two temperatures, and data for 37 degrees C and 1 Hz was obtained. Two of the ethyl methacrylate resins demonstrated the largest increases in storage (E') and loss moduli (E") after aging. These materials also showed the greatest overall E' and E". One denture liner material exhibited 673% and 488% increases in E' and E", and other materials showed smaller increases. The effects of aging on the damping factor (tan delta) were varied and five materials showed increased tan delta. Only two ethyl methacrylate resins developed lower tan delta. All the silicone and polyphosphazine rubbers showed small changes after aging and had the lowest tan delta values. Significance of differences between materials and treatments was tested with ANOVA, Scheffé intervals, and t-tests at a = 0.05. The ethyl methacrylate soft denture liners were affected the most by accelerated aging, and the silicones and polyphosphazine were least affected. The ethyl methacrylate resins also had the greatest values of E', E", and tan delta after aging. PMID:7473285

Wagner, W C; Kawano, F; Dootz, E R; Koran, A



Prosthetic rehabilitation of head and neck cancer patients focusing on mandibular dentures in irradiated patients.  


Purpose: This retrospective study assessed treatment outcomes and patient satisfaction of irradiated head and neck cancer patients treated with mandibular implant overdentures (IODs) or conventional dentures (CDs). Materials and Methods: Fifty-one irradiated head and neck cancer patients, out of a total of 158 patients included, completed the standardized questionnaire and underwent a clinical assessment. Nineteen patients were treated with removable CDs and 32 patients received IODs between January 2006 and January 2011. The mean follow-up of patients was 5.75 years (range: 1 to 23 years). Results: A total of 45 (88.3%) mandibular dentures were in function at the time of assessment. The overall denture satisfaction was 7.3 (range: 1 to 10, SD: 2.14). Patients being treated with adjuvant concepts, including surgical tumor ablation, scored worse than patients after radiation therapy alone. Edentulous patients seem to benefit from implants, especially with respect to prosthesis retention. Men take more benefit from IODs compared with women. Conclusions: The results are comparable to other studies of head and neck cancer patients and also of healthy individuals. Surgical interventions in adjuvant therapy concepts lead to reduced denture satisfaction. The concept of prosthetic rehabilitation as part of oncologic treatment can be judged as successful. PMID:24179970

Buurman, Doke J M; Vaassen, Lauretta A; Bockmann, Roland; Kessler, Peter


Metallurgical evaluation of heat-treated nickel-chromium base denture alloy  

Microsoft Academic Search

In this study, a combination of solution treatment at 1050°C for 60 min, quenching, and age hardening at 900°, 750° and 600°C for 6, 60, 600 min was carried out on as-east nickel-chromium-beryllium base denture alloy (Ticonium Premium 100 \\

Essam El Saeid Al Wakeel



Construction faults, age, gender, and relative medical health: Factors associated with complaints in complete denture patients  

Microsoft Academic Search

Statement of problem. Many practitioners will experience a situation, whereby a patient with newly fabricated complete dentures continues to experience difficulty in adapting to them. This can lead to a protracted period of discouraging “adjustment appointments” that may not result in the eventual resolution of the problem. Therefore it is often concluded that there is some patient factor, either age,

Demetrio L. Brunello; Michael N. Mandikos



Incorporation of radio frequency identification tag in dentures to facilitate recognition and forensic human identification.  


Forensic identification using odontology is based on the comparison of ante-mortem and post mortem dental records. The insertion of a radio frequency identification (RFId) tag into dentures could be used as an aid to identify decomposed bodies, by storing personal identification data in a small transponder that can be radio-transmitted to a reader connected to a computer. A small passive, 12 x 2,1 mm, read-only RFId-tag was incorporated into the manufacture of three trial complete upper dentures and tested for a signal. The aim of this article is to demonstrate the feasibility of manufacturing such a dental prosthesis, the technical protocols for its implantation in the denture resin and its working principles. Future research and tests are required in order to verify human compatibility of the tagged denture and also to evaluate any potential deterioration in strength when subjected to high temperatures, or for damage resulting from everyday wear and tear. It should also be able to withstand the extreme conditions resulting from major accidents or mass disasters and procedures used to perform a forensic identification. PMID:20657641

Nuzzolese, E; Marcario, V; Di Vella, G



[Laser technologies for the making of dentures, orthodontic appliances, metallic and sapphire implants and root pins].  


The authors analyze 10-year experience gained in the use of patented laser technologies for making metal dentures, orthodontic devices, metal and sapphire implants, radical pins, and other structures from various metal dental alloys (steel IXI8H9T, cobalt-chromium, silver-palladium, gold, titanium, etc.). Kvant-155, a new-generation Russian laser device, is described. PMID:10368609

Prokhonchukov, A A; Smirnov, A I; Rebrov, V I; Shatakhtsian, R E



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

PubMed Central

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.

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



Incorporation of Radio Frequency Identification Tag in Dentures to Facilitate Recognition and Forensic Human Identification  

PubMed Central

Forensic identification using odontology is based on the comparison of ante-mortem and post mortem dental records. The insertion of a radio frequency identification (RFId) tag into dentures could be used as an aid to identify decomposed bodies, by storing personal identification data in a small transponder that can be radio-transmitted to a reader connected to a computer. A small passive, 12 x 2,1 mm, read-only RFId-tag was incorporated into the manufacture of three trial complete upper dentures and tested for a signal. The aim of this article is to demonstrate the feasibility of manufacturing such a dental prosthesis, the technical protocols for its implantation in the denture resin and its working principles. Future research and tests are required in order to verify human compatibility of the tagged denture and also to evaluate any potential deterioration in strength when subjected to high temperatures, or for damage resulting from everyday wear and tear. It should also be able to withstand the extreme conditions resulting from major accidents or mass disasters and procedures used to perform a forensic identification.

Nuzzolese, E; Marcario, V; Di Vella, G



The psychological benefits of dental implants in patients distressed by untolerated dentures  

Microsoft Academic Search

It has been claimed that permanent dental implants improve the well-being of patients distressed by their removable dentures. Research appears to suggest that this improvement is temporary but the findings have been obscured by the use of inappropriate measures of distress, failure to control for Type II and (in ubiquitous use of repeated pair-wise testing) Type I statistical error, poor

Stan Lindsay; Keith Millar; Kevin Jennings



Zinc poisoning from excessive denture fixative use masquerading as myelopolyneuropathy and hypocupraemia.  


A 50-year-old man presented with a four-year history of unsteadiness, with recent falls and tingling in his fingers. Neurological examination found an ataxic gait, with a positive Romberg's sign. There was distal wasting and weakness in all four limbs and impaired co-ordination, with pseudoathetosis in the arms. Initial investigations showed a normochromic, normocytic anaemia, leucopenia, neutropenia and a low vitamin B(12) (172 ng/L). Treatment with intramuscular cobalamin injections showed no clinical improvement. Further investigations showed an undetectable caeruloplasmin (<0.085 g/L), a very low serum copper (1.1 ?mol/L) and a markedly raised serum zinc concentration (36.2 ?mol/L). On detailed questioning it became apparent that he had ill-fitting dentures requiring excessive use of denture fixative with high zinc content. The patient was switched to a non-zinc containing denture fixative and commenced copper supplementation. Although within three months the bone marrow suppression had resolved, there was no clinical improvement in neurological presentation. Questioning a patient about their denture fixative usage and checking if zinc is an ingredient may be considered during an investigation for myelopolyneuropathy when vitamin B(12) deficiency is not a cause. PMID:21525151

Barton, A L; Fisher, R A; Smith, G D P



Fracture surface characteristics of damaged acrylic-resin-based dentures as analysed by SEM-replica technique.  


The aim of this study was to determine some characteristics of the fracture surface of an acrylic resin denture. For this purpose, five complete upper dentures and two complete lower dentures that had fractured into two pieces were collected, the fracture surfaces were duplicated with the SEM-replica technique and duplicated surfaces were investigated with a scanning electron microscope. The reproducibility of the SEM-replica technique was tested by comparing one original sample surface and its replica surface of the same area. The SEM-photomicrographs revealed a series of fine striations in the fracture surfaces of both the upper and lower dentures perpendicularly orientated to the direction of the fracture propagation. A smooth area on the fracture surface was assumed to indicate a slow fatigue fracture process, and a rougher area fracturing with increased velocity. PMID:8866264

Vallittu, P K



The effect of acquired salivary pellicle on the surface free energy and wettability of different denture base materials  

Microsoft Academic Search

Objective: The objective of the present study was to evaluate the effect of salivary coating on the wettability and surface free energy of different denture base materials.Methods: Five acrylic resin and two metallic denture base materials were investigated. Ten specimens of each material (20×15×1.5mm) were fabricated and a standardized method was used for polishing the test specimens. Whole unstimulated saliva

C Sipahi; N Anil; E Bayramli



Shear bond strength between light polymerized hard reline resin and denture base resin subjected to long term water immersion  

PubMed Central

Statement of the problem The effect of long-term water immersion on the shear bond strength between denture base resin and Triad visible-light-polymerized (VLP) direct hard reline resin is not known. Purpose The aim of this study was to investigate the bonding characteristics of Triad VLP direct hard reline resin to heat-polymerized denture base resin subjected to long-term water immersion. Material and methods Ninety circular disks, 15 mm in diameter and 3 mm thick, of denture base resin were polymerized from a gypsum mold. Sixty specimens were subjected to water immersion and 30 were stored at ambient room temperature for 4 months. Thirty water-immersed specimens were dried with gauze (group 1), while the other 30 water-immersed specimens were dried with a hair dryer (group 2). The dry specimens (n = 30) represented the control group (group 3). All specimens were air abraded and painted with bonding agent before packing Triad VLP direct hard-reline resin. Specimens in each group were subjected to thermal cycling for 50,000 cycles between 4 °C and 60 °C water baths with 1-min dwell time at each temperature. The bond strength at which the bond failed under stress was recorded using a universal testing machine. One-way ANOVA and Tukey post hoc comparison were applied to find significant differences between groups (? = 0.05). Results Significant differences in mean shear bond strength among the specimens existed because of variable water content in the denture base resin (P < 0.05). Group 3 (dry) was higher than group 2 (desiccated), and the lowest was group 1 (saturated). Conclusion The shear bond strength of Triad VLP direct hard reline resin to denture base resin depended on the water content in the denture base resin. The dry denture base resin demonstrated superior bond strength compared with the desiccated and water-saturated denture base resins.

Al Rifaiy, Mohammad Q.



Complex Partial Seizures  


Complex Partial Seizures You are here: Home About Epilepsy Seizures Partial Seizures Complex Partial Seizures Email Print Twitter Facebook MySpace Delicous ... Complex Partial Seizures ] First Aid for Complex Partial Seizures Do not restrain the person. Remove dangerous objects ...


Influence of Prosthetic Screw Material on Joint Stability in Passive and Non-Passive Implant-Supported Dentures  

PubMed Central

Objectives: This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit. Methods: Ten mandibular implant-supported dentures were fabricated. Twenty cast models were fabricated using these dentures. Four groups (n=10) were tested, according to the vertical fit of the dentures [passive and non-passive] and prosthetic screw materials [titanium (Ti) or gold (Au) alloy]. The one-screw test was performed to quantify the vertical misfits using an optic microscope. The loosening torque for the prosthetic screws was measured 24 hours after the tightening torque (10 Ncm) using a digital torque meter. Data were analyzed by two-way ANOVA and Tukey’s test (?=0.05). Results: Overall, dentures with passive fit and Ti screws resulted in significantly higher loosening torque of the prosthetic screws (p<0.05). No significant interaction was found between fit level and screw material (p=0.199). The prosthetic screw material and fit of implant-supported dentures have an influence on screw joint stability. Ti screws presented higher joint stability than Au screws and minimum of misfit should be found clinically to improve the mechanical behavior of the screw joint.

Spazzin, Aloisio Oro; Henriques, Guilherme Elias Pessanha; de Arruda Nobilo, Mauro Antonio; Consani, Rafael Leonardo Xediek; Correr-Sobrinho, Lourenco; Mesquita, Marcelo Ferraz



Cephalometric evaluation of maxillomandibular relationships in patients wearing complete dentures: a pilot study.  


The purpose of this study was to evaluate the changes in vertical and sagittal maxillomandibular relationship of the patients who had been wearing dentures for an extensive period. Fifteen edentulous patients (seven men and eight women; mean age 63.5 years) who had worn dentures for six to 16 years (mean 10 years) were selected for this study. New prostheses were fabricated by conventional methods, and the patients were evaluated cephalometrically before and after the new prosthesis. The results were compared by Wilcoxon signed rank test (P < .05). Results indicated that a prognathic mandible and a pseudo Class III relationship with a reduced occlusal vertical dimension became a normal Class I maxillomandibular relation when the new prosthesis was inserted. A better facial profile was achieved. PMID:16279829

Ciftçi, Yalçin; Kocadereli, Ilken; Canay, Senay; Senyilmaz, Pinar



The effect of pH on the cytotoxicity of eluates from denture base resins.  


This in vitro study examined the effects of environmental pH on elution of potentially toxic substances from heat-, light-, and dual- (chemical plus light) polymerized denture base resins. Eluates were prepared by daily transfer of disks to fresh buffers at pH 4.0, 5.0, and 6.8 over a 5-day period. Oral epithelial cells were plated in culture dishes in medium containing the eluate. After 24 hours, cellular RNA synthesis was assessed by measuring tritiated uridine uptake. Effects of materials were compared to identical cultures that contained the appropriate buffer without the eluate. The results indicate that the cytotoxic components leach out of the denture base resins in different amounts and at different rates, and the amount of leaching can be affected by pH. PMID:7575962

Lefebvre, C A; Schuster, G S; Marr, J C; Knoernschild, K L


An innovative metal base denture design for a 55-year-old menopausal woman  

PubMed Central

Menopause is a normal developmental stage in a woman's life, marking the permanent cessation of menstruation resulting from irreversible changes in the hormonal and reproductive functions of the ovaries and is associated with a large number of symptoms ranging from physical to psychological. Some of the common oral manifestations are oral burning sensation with associated mucosal infections, pain, altered taste perception, and alveolar bone loss. These symptoms may unfavorably affect oral health and treatment needs requiring dentists to devise newer methods that would add along to the treatment modalities advised by gynecologists in relieving menopausal women from above symptoms. The present case report describes an innovative method of fabricating a metal base denture in an edentulous female that would help perimenopausal/menopausal/post-menopausal edentulous women feel hot/cold sensations of food/liquids, thereby giving them relief from pain, better taste perception, and relief from associated allergic and candidal infections that are common with conventional acrylic base dentures.

Bhatia, Vishwas; Bhatia, Garima; Jain, Nitul; Jadon, Ashwani Kumar



Effect of different surface treatments on tensile bond strength of silicone-based soft denture liner  

Microsoft Academic Search

Failure of the bond between the acrylic resin and resilient liner material is commonly encountered in clinical practice. The\\u000a purpose of this study was to investigate the effect of different surface treatments (sandblasting, Er:YAG, Nd:YAG, and KTP\\u000a lasers) on tensile bond strength of silicone-based soft denture liner. Polymethyl methacrylate test specimens were fabricated\\u000a and each received one of eight surface

Hakan Akin; Faik Tugut; Burcu Mutaf; Gulsah Akin; A. Kemal Ozdemir


An in vitro analysis of wear resistance of commercially available acrylic denture teeth.  


Posterior denture teeth wear faster than the anterior teeth, causing occlusal prematurities and loss of vertical dimension of occlusion. The loss of vertical dimension of occlusion lays more stress on the anterior alveolar ridge, which in turn increases the rate of residual ridge resorption and causes loss of alveolar ridge height in the anterior segment and compromises esthetics. Hence it is important for the clinician to choose acrylic resin teeth with high wear resistance. The objective of the study is to investigate and compare the wear resistance of three different commercially available acrylic resin denture teeth. 60 specimens were tested for wear resistance in terms of loss of weight and loss in volume on a wear and friction monitor for 5,000 cycle wear periods (total of 10,000 cycles) under a 0.20 kg load. Statistical analysis used: The findings were analyzed using one way analysis of variance (ANOVA) and Tukey HSD test. Comparison of weight loss and volume loss between Surana ultradent, Premadent and Dentek showed highly significant difference, Surana ultraddent having better wear resistance. Surana ultradent acrylic resin denture had highest wear resistance amongst the three groups of tested samples. PMID:21886405

Shetty, Mallika S; Shenoy, K Kamalakanth



Evaluating surface roughness of a polyamide denture base material in comparison with poly (methyl methacrylate).  


Polyamide denture base materials are more flexible than the commonly used poly (methyl methacrylate) (PMMA). However polishability of polyamides has not been examined adequately. This study investigated the surface roughness (Ra) and clinical acceptability of samples of a polyamide denture base material and PMMA fabricated by injection moulding and traditional heat processing systems, respectively. Half of each sample surface was polished using the conventional technique (lathe with pumice followed by high shine buffs) and the other half was left unpolished. A profilometer was used to measure Ra along 3 tracks on each surface before and after polishing. Two-way ANOVA was used to compare the two surfaces of the two materials for variations in Ra values. Polyamide denture base material when polished with conventional laboratory technique became more than 7 times smoother whereas processed PMMA when polished became more than 20 times smoother using the same polishing technique. However the surface roughness of polyamide is well within the accepted norm of 0.2 µm Ra. Polyamide produces a clinically acceptable smoothness after conventional polishing by lathe. PMID:21206160

Abuzar, Menaka A; Bellur, Suman; Duong, Nancy; Kim, Billy B; Lu, Priscilla; Palfreyman, Nick; Surendran, Dharshan; Tran, Vinh T



Energy absorption and hardness of chair-side denture soft lining materials.  


The purpose of this study was to evaluate the hardness and energy absorption properties of four commercially available chairside silicone denture soft lining materials and to compare their properties with those of a heat-polymerized silicone denture liner. The denture lining materials investigated were four auto-polymerising silicone soft liners (GC Reline Soft, Ufigel SC, Elite Soft Relining and Tokuyama Sofreliner S) and a heat-polymerised silicone liner (Molloplast B). The soft liners were processed according to manufacturers' instructions. The specimens for hardness testing were 38 x 38 x 3 mm. The specimens for energy absorption test were 10 x 10 x 3 mm. In each test ten samples of each material were tested. There was strong evidence that Tokuyama Sofreliner S and, to a lesser extent, Ufigel SC, were less stiff and more resilient than Molloplast B. There was also strong evidence that both GC Reline Soft and Elite Soft Relining were harder than Molloplast B, while Ufigel SC and Tokuyama Sofreliner S were softer In conclusion differences existed between hardness and energy absorption properties of the soft lining materials. PMID:21265439

Tasopoulos, Theodorus; Jagger, Robert G; Jagger, Daryll C; Griffiths, Alex E



A comparison of monomer conversion and inorganic filler content in visible light-cured denture resins.  


Visible light-cured (VLC) denture resins are relatively new products used for the reline and repair of dentures. The conversion of monomer into polymer in 3 brands of visible light-cured denture resins was investigated. The relationship of the inorganic filler content to this conversion was also studied. It was determined that these reline materials vary in monomer conversion and weight percentage of filler, and this variation is brand dependent. The monomer conversion ranged from 77% to 97%. Significant differences in these values were found when duration of light exposure was increased. In addition, resin nearest to the light source polymerized to a greater extent when compared to resin that was 1 mm deep to this surface, hence furthest from the light source. The inorganic filler content ranged from 0% to 15%. For the resin systems studied, the relationship between monomer conversion and inorganic filler loading was inversely proportional. Results indicated that monomer conversion of VLC repair resins was affected by the duration of light exposure as well as the amount of inorganic filler present in the material. PMID:1291397

Barron, D J; Rueggeberg, F A; Schuster, G S



Comparative study of methods for the quantification of biofilm on complete dentures.  


This study compared the application and reliability of 4 methods for biofilm quantification (computerized, paper-weighing, point-counting, and planimetric) in complete dentures, verifying the correlation between them. The internal surfaces of 62 complete dentures were stained (5% erythrosine) and photographed. The slides were projected on paper, and the areas (total and biofilm-covered) were outlined with a pencil. These areas were measured with an equidistant point grid (point-counting method), a digital planimeter (planimetric method), and for the paper weighing method they were cut and weighed with a precision scale. For the computerized method, ImageTool software was used. In order to perform a validation test of the methods, all of them were applied to slide projections of geometric figures with known dimensions. The correlation tests showed high correlation values (r = 0.82 to 0.99) among the methods. The validation test (ANOVA) showed no statistically significant differences among the values obtained from the measurement of figures using all four quantitative methods and the real dimensions of these geometric figures. Quantitative methods were efficient and reliable for measuring quantity of biofilm in complete dentures, and may be useful in experimental studies on the efficacy of hygiene products. The computerized method was fast and easy to perform. PMID:15619874

Paranhos, Helena de Freitas Oliveira; da Silva, Cláudia Helena Lovato


Photoelastic analysis to compare implant-retained and conventional obturator dentures  

NASA Astrophysics Data System (ADS)

The use of photoelastic analysis contributes to the rehabilitation of patients with oral-sinus-nasal sequelae, which in turn affect important functions such as chewing, swallowing, and speech. The prosthetic rehabilitation with implant-retained dentures is a suitable treatment option. The purpose of this study was to verify, by using a photoelastic analysis, the stress distribution in implant-retained palatal obturator dentures (relined or not) associated with different attachment systems (O-ring, bar-clip, and bar-clip associated with distally placed O-rings). Two photoelastic models were obtained from an experimental maxillary cast presenting an oral-nasal communication. One model had two 13-mm length implants placed on the left region. A total of eight colorless maxillary obturators were fabricated and subsequently four of them were relined with soft silicone soft, and three had attachment systems associated. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a 100-N load was applied at 10 mm/s. The results showed that the denture relining influenced the distribution and amount of stress on the models. The O-ring group displayed the lowest stress levels, followed by bar-clip system associated with distally placed O-rings and bar-clip groups.

Goiato, Marcelo Coelho; Prado Ribeiro, Paula do; Pellizzer, Eduardo Piza; Pesqueira, Aldiéris Alves; Haddad, Marcela Filiè; dos Santos, Daniela Micheline; Moreno, Amália



[A study on the improvement of denture base resin. Epoxy dimethacrylate-polybutadiene dimethacrylate-MMA monomers as the liquid of denture base resin].  


The dimethacrylates, EpDMA and BdDMA, which have a bisphenol type epoxy chain and butadiene chain in their main chains, respectively, were synthesized. The properties of the terpolymer composed of EpDMA, BdDMA and MMA monomers were examined. The monomer mixture of EpDMA, BdDMA and MMA was used as the liquid of denture base resin, and the properties of the cured resin were examined. The polymerization shrinkage of the terpolymer of EpDMA-BdDMA-MMA decreased with the increase in the EpDMA concentration in the cured resin, and the transverse strength and the elastic modulus were greatest at the BdDMA concentration of 0.3-1 vol%. The denture base resin produced using a monomer mixture as the liquid, the transverse strength and the impact strength showed the highest values of about 110 MPa and 14 KJ/m2, respectively, at the liquid composition of 10 vol% EpDMA, 1 vol% BdDMA and 89 vol% MMA. PMID:2134818

Teshima, H; Matsukawa, S



[Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].  


Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (p<0.05) (a dual wing + horizontal groove 222±9 N). The highest fracture strengths were observed with dual wing + occlusal rest FPDs: 250±10 N compared to inlay-retained FPDs (p<0.001) and wing-retained FPDs (p<0.001). FEA showed more favorable stress distributions within the tooth/restoration complex for dual wing retainers+ occlusal rest FPDs. There was stress concentration around connectors and retainers near connectors. A dual-wing retainer with occlusal rest is the optimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs. PMID:23715455



Candida colonisation and the efficacy of chlorhexidine gluconate on soft silicone-lined dentures of diabetic and non-diabetic patients.  


OBJECTIVES: The aim of this study was to evaluate Candida colonisation in the dentures with silicone soft liner in diabetic and non-diabetic patients and to assess the antifungal efficacy of chlorhexidine gluconate on Candida colonies. MATERIALS AND METHODS: Thirty patients with resorbed ridges, fifteen each in the diabetic and non-diabetic group, were selected. The mandibular denture of each patient was lined with heat-polymerised silicone resilient liner. Patients were instructed to clean the dentures with soap water and brush. Samples from the fitting surface of mandibular dentures were collected at 15, 21 and 30 days. Subsequently, samples were collected at 15, 21 and 30 days, after cleaning the dentures with a detergent solution of 4% chlorhexidine gluconate, and incubated for the evaluation of Candida growth. These data were subjected to statistical analysis by Mann-Whitney U-test. RESULTS: Normal oral flora in diabetics and non-diabetics showed no difference (p > 0.05). The density of colonies increased after 21 and 30 days in diabetic patients (p < 0.05). Number of Candida colonies significantly reduced in both the groups after 21 and 30 days of cleaning the dentures with 4% chlorhexidine gluconate (p < 0.05). CONCLUSION: Dentures with silicone resilient liner exhibit increased Candida growth in diabetic patients. Four per cent chlorhexidine gluconate solution effectively disinfects these dentures. PMID:23137002

Mantri, Sneha S; Parkhedkar, Rambhau D; Mantri, Shivkumar P



Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity  

PubMed Central

PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.

Shah, Farhan Khalid; Gebreel, Ashraf; Elshokouki, Ali hamed; Habib, Ahmed Ali



A subjective study of dimensional stability of permanent acrylic resin complete denture bases after a second curing cycle.  


The aim of this study was to subjectively assess permanent denture base retention and stability in order to determine whether detrimental change occurred as a result of a second curing cycle. 100 complete upper denture bases were assessed by clinician and patient using visual analogue scales at try-in and insert. No statistically significant alteration in mean scores for retention and stability was seen. 5% of bases showed some deterioration, but none required rebasing or remaking as a result. The advantages of permanent bases during denture construction seem to outweigh the risk of loss of retention and/or stability as a result of distortion due to the second curing cycle. PMID:15521392

Ellis, Janice S; Read, Graham E; Thomason, J Mark



An implant-supported removable partial denture on milled bars to compromise the inadequate treatment plan: a clinical report  

PubMed Central

Presurgical prosthetic treatment planning is critical for the success of the implant prosthesis. Inadequate treatment plan, due to insufficient discussion between prosthodontist, and surgeon, may result in poor prognosis. A 26-year-old male patient was referred for prosthodontic treatment after implant was placed in the area of teeth #17, 16, 22, 25 and 27, without adequate discussion nor the treatment planning between oral surgeon and prosthodontist. It was found that the patient had two hopeless teeth, and a severely resorbed alveolar ridge. Additional tooth extraction was needed and the type of definitive prosthesis was shifted from fixed type to removable one. Proper pre-surgical treatment planning is essential for the good prognosis. Implant-supported removable prosthesis on milled bars may be a useful treatment option in patients with incorrect angled placement on severely resorbed alveolar ridge.

Kim, Jee-Hwan



[Removal of fixed partial dentures without destruction, our experience with the KaVo CORONAflex crown removing instrument].  


Removal of fixed, cemented restorations is a great challenge for dental practitioner in the everyday activity. After all, prosthodontic textbooks cover only briefly the destructive methods of fixed restoration's removal and does not deal with other techniques. In many cases--i.e. at fracture of porcelain that can not be repaired in the mouth, or loosening of one anchor in a multi-unit bridgework--it would be necessary to remove the bridge without destruction. Only few literature data is available on this topic. From 1998 we have made an attempt with the KaVo CORONAflex instrument to remove various types of fixed restorations without destruction. The indication of removal, the material of the bridge, location of abutment teeth in the dental arch and success of the removal were documented in each cases. From the 81 fixed prostheses 61 were successfully removed without any destruction. Sixty two of the restorations were porcelain fused to metal; 19 of them were cast restorations with acrylic resin facing (single crowns or bridges). In most of the cases the removal of the fixed prostheses was successful without any damage, and consequently remaking of the restorations was not necessary. In this way the additional stresses associated with the patients' dental treatment could be avoided and also time and dental as well as laboratory fees could be spared. PMID:17444129

Bertold, Molnár; Endre, Somogyi; Pál, Fejérdy



Electrophoresis of tear proteins as a new diagnostic tool for two high risk groups for dry eye: computer users and contact lens wearers  

PubMed Central

Rationale: Dry eye is the most prevalent condition seen by the ophthalmologist, in particular in elderly. The identification of new common risk factors (computer use and contact lens wear) extends the disease among the young people. The early diagnosis of dry eye is essential, but difficult, because the biochemical changes in tear film usually occur before any detectable signs. Due its advantages, electrophoresis of tear proteins could be an important tool for diagnosis of tear film impairment in high risk groups for dry eye. Objective: The role of tear proteins electrophoresis in early diagnosis of dry eye related to computer use and contact lens wear, as well as the biochemical changes in these high risk groups are presented. Methods: This review will summarize the actual data concerning the electrophoretic changes of tear proteins in computer users and contact lens wearers, two common high risk groups for dry eye. Discussion: Electrophoresis of tear proteins using automated system Hyrys–Hydrasys SEBIA France is an important tool for early diagnosis of tear film alterations and monitoring of therapy. The quantification of many proteins in a single analysis using a small quantity of unconcentrated reflex tears is the main advantage of this technique. Electrophoresis of tear proteins should became a prerequisite, in particular for computer users less than 3h/day, as well as at prescribing contact lenses. Abbreviations: DED– dry eye disease, EGF–epidermal growth factor, IL interleukins, MMP–metalloproteinase, ELISA– Enzyme–linked immunosorbent assay, SDS– sodium dodecyl sulfate, CVS– computer vision syndrome, CLRDE– contact lens– related dry eye



Sensitivity of Candida Albicans Biofilm Cells Grown on Denture Acrylic to Antifungal Proteins and Chlorhexidine  

PubMed Central

Objectives Candida albicans cells form biofilms on polymeric surfaces of dentures and other prostheses introduced into the oral cavity. Many biofilm microorganisms exhibit resistance to antimicrobial agents; C. albicans cells may also develop resistance to naturally-occurring antifungal peptides in human saliva including histatins (Hsts) and defensins (hBDs). Therefore, we evaluated Hst 5 activity on C. albicans biofilm cells compared to planktonic cells and measured whether surface treatment of denture acrylic with Hst 5, hBD-3, or chlorhexidine gluconate could inhibit in vitro biofilm development. Methods Acrylic disks were preconditioned with 500 ?l saliva for 30 min, and inoculated with C. albicans cells (106 cells/ml) for 1 h, at 37 °C. Non-adherent cells were removed by washing and disks and were incubated in YPD growth medium for 24, 48, and 72 h at 37 °C. Candidacidal assays were performed on 48-hour-biofilms and on planktonically-grown cells using Hst 5 (15.5 ?M, 31.25 ?M, 62 ?M). Cell adhesion was compared on disks pre-coated with 0.12% chlorhexidine gluconate, 50 ?M Hst 5, or 0.6 ?M hBD-3 after 24 h, 48 h, and 72 h growth. Results No significant difference was observed in sensitivity to Hst 5 of biofilm cells compared to planktonic cells (p > 0.05). Pre-coating disks with hBD-3 did not inhibit biofilm development; however, Hst 5 significantly inhibited biofilm development at 72 h, while 0.12% chlorhexidine significantly inhibited biofilm development at all time intervals (p < 0.05). Conclusions C. albicans biofilm cells grown on denture acrylic are sensitive to killing by Hst 5. Surface coating acrylic with chlorhexidine or Hst 5 effectively inhibits biofilm growth and has potential therapeutic application.

Pusateri, Christopher R.; Monaco, Edward A.; Edgerton, Mira



The elastomers for complete denture impression: A review of the literature  

PubMed Central

This article reviews the current trends in materials used for complete denture impression. Peer-reviewed articles, published in English and in French between 1954 and 2007, were identified through a MEDLINE search (Pubmed and Elsevier) and a hand search of relevant textbooks and annual publications. Emphasis was made on the characteristics of the elastomers, their manipulation, the different techniques used, and the quality of the impression obtained. The combination of excellent physical properties, handling characteristics, and unlimited dimensional stability assures the popularity of these impression materials.

Daou, Elie E.



Repair of denture base resins using visible light-cured materials.  


Specimens of denture base resins were repaired with autopolymerizing and visible light-cured (VLC) repair materials. Flexural properties were measured and revealed that the highest strength and toughness of joint are obtained by the autopolymerizing repair material and are independent on the base resin. The VLC materials exhibited a lower repair strength (22% to 58%) and toughness (9% to 33%) than those of the autopolymerizing resin. No interaction between base and repair material was detected, which was attributed to poor adhesive bonding created at the interface. PMID:7844744

Andreopoulos, A G; Polyzois, G L



Effect of investment material and water immersion time on tooth movement in complete denture.  


This study verified the effect of the association gypsum or silicone investment support materials and water immersion on the relative tooth movement in complete dentures. Wax record bases with teeth were assigned to 2 groups (n=10): 1--type III dental stone (control), and 2--condensation silicone. Linear distances (mm) between teeth were recorded after deflasking and after water storage for 1 week, 1 month and 3 months. With the exception of the silicone for the pre-molar distance after water storage for 3 months, the association between the type of investment and period of water storage did not alter the distances between teeth. PMID:16411573

Boscato, Noéli; Consani, Rafael Leonardo Xediek; Consani, Simonides; Del Bel Cury, Altair Antoninha



Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture.  


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. PMID:24015016

Jain, Ashish R; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew



An in vitro study into the effect of a limited range of denture cleaners on surface roughness and removal of Candida albicans from conventional heat-cured acrylic resin denture base material.  


This study evaluated the abrasiveness of four denture cleaners on the surface of denture base material and assessed their ability to remove Candida albicans. Acrylic resin discs 20 mm diameter and 2 mm thick were identically produced and polished. Four cleaners were evaluated: conventional toothpaste; toothpaste with stain remover; denture cleaning paste and an immersion type cleaner, and water were used as control. These were used at dilutions of 1:1, 1:2 and 1:3 with water. An electric toothbrush was used, and the discs cleaned to simulate 1 years' cleaning. The surface roughness of the discs were then measured, before and after cleaning, using a stylus profilometer, then inoculated with 1.2 x 10(6)C. albicans cells. The effectiveness of the denture cleaners to remove C. albicans cells was assessed following a single cleaning event. The immersion cleaner was significantly less abrasive than paste cleaners (P < 0.05). There were no significant differences between any dilutions for any cleaner used (P > 0.05). Immersion and paste cleaners removed almost all recoverable C. albicans from the discs, as cleaning with water alone was less effective (P < 0.05). An immersion type cleaner was found to be the most suitable cleaner because of its low abrasivity and effective removal of organic debris. PMID:15140172

Harrison, Z; Johnson, A; Douglas, C W I



An Electromyographic Analysis of Orbicularis Oris and Buccinator Muscle Activity in Patients with Complete Dentures Fabricated Using Two Neutral Zone Techniques-A Pilot Study.  


PURPOSE: Several studies have evaluated electromyographic (EMG) activity of perioral muscles in patients using unsatisfactory old complete dentures and after the insertion of new clinically acceptable dentures; however, studies evaluating EMG activity of orbicularis oris (OO) and buccinator (BUC) muscles in patients wearing complete dentures fabricated using swallowing (SNZ) and phonetic neutral zone (PNZ) techniques are lacking in the literature. The purpose of this study was to evaluate differences in muscle activity of the superior orbicularis oris (SOO), inferior orbicularis oris (IOO) and BUC muscle during the use of unsatisfactory old complete dentures, in comparison with the satisfactory dentures fabricated using the two neutral zone techniques. MATERIALS AND METHODS: Ten completely edentulous participants dissatisfied with their existing mandibular complete dentures participated in the study. Each patient received two sets of new dentures fabricated using the SNZ and PNZ techniques. Surface EMG activity of the OO and BUC muscles was recorded using a 4-channel Medelec premier plus electromyography machine while the patients still used their old dentures (group A) and with the SNZ (group B) and PNZ (group C) dentures. On the basis of participation in the study, five participants first received the SNZ dentures and five the PNZ type. After having worn the prosthesis for a minimum of 2 months, EMG recordings were repeated for the first set of dentures. The prostheses were then changed and the procedures repeated. The activity of OO and BUC muscles was recorded at rest, while pursing and laughing, and during pronunciation of various syllables. Results are expressed as mean ± SD and as absolute numbers and percentage. ANOVA with appropriate correction (Bonferroni or Tamhane) and Student's t-test were used for statistical analysis. A p-value < 0.05 was taken to indicate a significant difference. RESULTS: There was no statistically significant difference in the mean EMG activity of SOO, IOO, and BUC muscles at rest, or during pursing or laughing among the three groups. No significant difference was observed in the mean EMG activity of SOO and BUC muscle among the groups for all the syllables pronounced. For IOO, a statistically significant difference was observed among the groups for the words "baby" and "cheese." Within-group comparisons of the mean EMG activities of SOO and IOO during pronunciation and pursing showed no significant difference; however, at rest a statistically significant difference was observed in group B. CONCLUSION: OO and BUC muscle activities did not significantly differ, irrespective of the technique used for fabrication of complete dentures.  PMID:23725009

Ladha, Komal G; Gill, Shubhra; Gupta, Rekha; Verma, Mahesh; Gupta, Meena



Effect of Flask Closure Method and Post-Pressing Time on the Displacement of Maxillary Denture Teeth  

PubMed Central

The purpose of this study was to verify the influence of flask closure methods and post-pressing times on tooth displacement in maxillary dentures. Twenty similar maxillary dentures were made using a heat-polymerized acrylic resin, and randomly assigned to 4 experimental groups (n=5) according to the protocol: 1-conventional flask closure and immediate polymerization; 2- conventional flask closure and polymerization after 6-hour post-pressing time; 3- RS flask closure system and immediate polymerization; and 4- RS flask closure system and polymerization after 6-hour post-pressing time. Three transverse and 2 anteroposterior linear distances between teeth were measured before and after the denture processing with an optical microscope with accuracy of 0.0005mm. Analysis of variance (ANOVA) and Tukey’s test were performed to compare the results. The 6-hour post-pressing time (conventional = 0.44mm and RS = 0.33mm) showed no statistically significant difference in tooth movement, in relation to the flask closure methods, when compared to the immediate time (conventional = 0.40mm and RS = 0.28mm). The RS system standardized the tooth displacement, independently of the post-pressing times. Dimensional changes were more uniform when the dentures were submitted to the 6-hour post-pressing time and RS flask closure method, suggesting that these factors may reduce the magnitude of tooth movement.

Negreiros, Wagner A; Consani, Rafael L.X; Mesquita, Marcelo F; Sinhoreti, Mario A.C; Faria, Ivan R



Hydrophilic surface modification of acrylic denture base material by silica coating and its influence on Candida albicans adherence.  


Silica coating modifies hydrophobic denture base materials to have a hydrophilic surface. The purpose of this study was to evaluate the effect of silica coating to a denture base material on resistance to Candida albicans (C. albicans) adherence. Specimens were prepared by polymerizing an acrylic denture lining material and polished using silicon carbide paper up an abrasive grade of 1000. The specimens of a coated group were treated three times by a silica coating agent using a nonwoven cloth. The surface properties were evaluated by contact angle measurement, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). A C. albicans adherence assay was performed after 1.5, 6, and 24 h incubation. The mean contact angle of the coated group showed significantly lower than that of the non-coated group (p < 0.05). In the coated group, the surface roughness decreased in SEM images, and Si was continuously detected in EDS analysis. At 24 h incubation time, the colony forming unit of C. albicans on the coated group was significantly reduced compared to the non-coated group (p < 0.05). These results suggest that hydrophilic surface modification by the silica coating reduces C. albicans adherence and could contribute to daily denture care. PMID:23896959

Azuma, Akinobu; Akiba, Norihisa; Minakuchi, Shunsuke



Evidence-based guidelines for the care and maintenance of complete dentures: a publication of the American College of Prosthodontists.  


The current rates of edentulism have been estimated to be between 7% and 69% of the adult population internationally. In the United States, while the incidence of edentulism continues to decline, rapid population growth coupled with current economic conditions suggest that edentulism and conventional denture use will continue at current or higher numbers. Unfortunately, evidence-based guidelines for the care and maintenance of removable complete denture prostheses do not exist. In 2009, the American College of Prosthodontists (ACP) formed a task force to establish evidence-based guidelines for the care and maintenance of complete dentures. The task force comprised members of the ACP, the Academy of General Dentistry, American Dental Association (ADA) Council on Scientific Affairs, the American Dental Hygienists' Association, the National Association of Dental Laboratories, and representatives from GlaxoSmithKline Consumer Healthcare. The review process included the assessment of over 300 abstracts and selection of over 100 articles meeting inclusion criteria of this review. The task force reviewed synopses of the literature and formulated 15 evidence-based guidelines for denture care and maintenance. These guidelines were reviewed by clinical experts from the participating organizations and were published in February 2011 issue of The Journal of the American Dental Association for widespread distribution to the dental community. These guidelines reflect the views of the task force. PMID:21324026

Felton, David; Cooper, Lyndon; Duqum, Ibrahim; Minsley, Glenn; Guckes, Albert; Haug, Steven; Meredith, Patricia; Solie, Caryn; Avery, David; Deal Chandler, Nancy



Measuring pressures under maxillary complete dentures during swallowing at various occlusal vertical dimensions. Part II: Swallowing pressures.  


The swallowing pressures of seven edentulous patients were measured at seven different occlusal vertical dimensions. In addition, the projection surfaces of the maxillary dentures were measured and the forces on the maxillary denture-bearing surfaces were calculated. The swallowing pressures were measured from the maxillary denture base-mucosal surface interface by means of a "closed" hydraulic system described in Part I. The mean values of swallowing pressures increased from 7.95 +/- 2.25 to 10.18 +/- 3.42 kPa as the occlusal vertical dimension increased, and then decreased to 8.38 +/- 3.55 kPa at the highest occlusal vertical dimension. The results of a two-way analysis of variance showed significant differences of swallowing pressures between patients (p less than 0.001) and between different occlusal vertical dimensions (p less than 0.001). The projection surfaces of maxillary denture bases were measured and ranged from 21.65 to 27.78 cm2. The forces exerted on these surfaces during swallowing were also calculated and ranged from 12.5 to 47.7 N. PMID:2072326

Avci, M; Aslan, Y



Influence of different flasking and polymerizing methods on the occlusal vertical dimension of complete dentures.  


The flasking and polymerization technique for resins can introduce stresses during processing which may lead to denture base distortions, artificial teeth displacement and increases in the occlusal vertical dimension (OVD). This study investigated whether the association of microwave heat-activation (MH) and bimaxillary flasking (BF) minimizes the possible increases in OVD after prostheses processing. Forty pairs of complete dentures were waxed with the artificial teeth in closed occlusion and divided into four groups according to investing and heating methods: G1 (control) = monomaxillary/water bath; G2 = monomaxillary/microwave; G3 = bimaxillary/water bath and G4 = bimaxillary/microwave. OVD was measured using a digital caliper before and after prostheses processing. Results were submitted to statistical analysis (Student's t-test for multiple comparisons and post hoc ANOVA, alpha = 0.05). Comparison of values before and after processing showed that OVD increased in all groups after polymerization (p < 0.001), regardless of flasking and polymerization methods. Statistically, G2 had the greatest difference in OVD when compared to G1 (p = 0.014), G3 (p = 0.019) and G4 (p = 0.024). G3 and G4 showed similar results statistically when compared to G1 (control). Both investing and heating methods resulted in an increase in OVD after processing. However, the prostheses invested in bimaxillary flasks showed the lowest changes in OVD, regardless of the polymerization method. PMID:23798079

Silva-Concílio, Lais R; Meloto, Carolina B; Neves, Ana Christina C; Cunha, Leonardo G; Rizzatti-Barbosa, Célia M



Developing the procedure of modifying the denture soft liner by silver nanoparticles.  


Colonization of denture soft lining materials by fungi and denture plaque leads to infections of mucosa. Microorganisms such as Candida albicans colonize not only the surface of the soft liners, but they also penetrate inside those materials. Therefore the use of common disinfectants, e.g., surface active cleaners, is not a perfect solution for keeping a proper hygiene of soft linings. Modifying soft lining by silver nanoparticles (AgNP) seems to be a right way to overcome those problems. The procedure of modifying two-component silicone material by silver nanoparticles (AgNP) is presented in the article. The solubility tests for both material components have been carried out in the first stage of examinations. On the basis of test results, a solvent has been selected, being a dispersion medium for AgNPs and both soft liner components. The effective method for evaporating a solvent from the composition has been developed. Material components with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) have been obtained. Cured samples of the composites have been examined by SEM to confirm the effectiveness of the procedure. PMID:22742207

Chladek, Grzegorz; Barszczewska-Rybarek, Izabela; Lukaszczyk, Jan



Mechanical Properties of Surface-Charged Poly(Methyl Methacrylate) as Denture Resins  

PubMed Central

The aim of this study was to examine the mechanical properties of a new surface-modified denture resin for its suitability as denture base material. This experimental resin is made by copolymerization of methacrylic acid (MA) to poly(methyl methacrylate) (PMMA) to produce a negative charge. Four experimental groups consisted of Orthodontic Dental Resin (DENTSPLY Caulk) as a control and three groups of modified PMMA (mPMMA) produced at differing ratios of methacrylic acid (5 : 95, 10 : 90, and 20 : 80 MA : MMA). A 3-point flexural test using the Instron Universal Testing Machine (Instron Corp.) measured force-deflection curves and a complete stress versus strain history to calculate the transverse strength, transverse deflection, flexural strength, and modulus of elasticity. Analysis of Variance and Scheffe Post-test were performed on the data. Resins with increased methacrylic acid content exhibited lower strength values for the measured physical properties. The most significant decrease occurred as the methacrylic acid content was increased to 20% mPMMA. No significant differences at P < .05 were found in all parameters tested between the Control and 5% mPMMA.

Park, Sang E.; Chao, Maggie; Raj, P. A.



The stress state of the fraenal notch region in complete upper dentures.  


The present study determines the stress field in the region of the labial flange of the complete upper denture (CUD). Using commercial edentulous molds and standardized procedures eight identical CUDs were fabricated with an initial fraenal notch of 5 mm. Three addition notch conditions were produced by deepening the notch two times giving a total depth of the notch of 7 and 9 mm respectively. Finally an incisal diastema of 7 mm was created in every CUD. Three elements rosette strain gauge was cemented onto the midline of each denture specimen near the fraenal notch, for calculating the two principal stresses and the maximum shear stress. It is less possible that a failure crack in a CUD will be initiated from the region of the fraenal notch, due to the compressive nature of the principal stresses (they are varied significantly among the four notch conditions with P=0.035 for ?(1) and P=0.007 for ?(2)) and the low value of the maximum shear stress. The creation of an incisal diastema significantly decreased the values of the principal stresses ?(1) (P=0.012) and ?(2) (P=0.025). Further investigation is needed to detect the region of the CUD where a failure crack may be initiated. PMID:22445585

Prombonas, Anthony E; Vlissidis, Dimitris S; Maria, Paralika A; Nikolas, Poulis A



An optical coherence tomography investigation of materials defects in ceramic fixed partial dental prostheses  

NASA Astrophysics Data System (ADS)

Metal ceramic and integral ceramic fixed partial prostheses are mainly used in the frontal part of the dental arch because for esthetics reasons. The masticatory stress may induce fractures of the bridges. There are several factors that are associated with the stress state created in ceramic restorations, including: thickness of ceramic layers, mechanical properties of the materials, elastic modulus of the supporting substrate material, direction, magnitude and frequency of applied load, size and location of occlusal contact areas, residual stresses induced by processing or pores, restoration-cement interfacial defects and environmental defects. 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 optical coherence tomography (OCT) in detection and analysis of possible material defects in metal-ceramic and integral ceramic fixed partial dentures.

Sinescu, Cosmin; Negrutiu, Meda; Hughes, Michael; Bradu, Adrian; Todea, Carmen; Rominu, Mihai; Laissue, Philippe L.; Podoleanu, Adrian Gh.



Improvement of mechanical and antimicrobial properties of denture base resin by nano-titanium dioxide and nano-silicon dioxide particles  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate the effects of nano-titanium dioxide and nano-silicon dioxide particles on the mechanical and antimicrobial properties of denture base resin. Design\\/methodology\\/approach – Nano-titanium dioxide and nano-silicon dioxide particles were introduced to heat-curing denture base resin to prepare composites. Electronic universal testing machine and friction tester were used to test tensile strength

Rong Song; Xiaohui Jiao; Long Lin



[Research related to pressures under dentures. The effect of differences in impression pressure with special reference to unilateral mandibular free-end edentulousness].  


The purpose of this paper is to investigate the difference of impression pressure under denture bases made by the pressure impression-taking method, which considers the resiliency of ligaments under abutment teeth and mucosa under dentures, and under those made by the non-pressure impression-taking method, and then analyzed its influence on the distribution of pressure curve produced by bite force with the case of unilateral mandibular free-end edentulousness. The findings were as follows: 1. As for the pressures under the dentures, dentures made by the pressure impression-taking method in all cases showed an apparent increase at the mesial part, while at the distal part, a decrease was detected in three out of five patients. 2. The pressure curve caused by bite force tended to rise sharply immediately before the application of maximum bite force. 3. Ratio of pressures resulting from the increased bite force tended to increase with dentures using the non-pressure impression-taking method, while dentures using the pressure impression-taking method showed a clear tendency to equalize toward 0.5, regardless of the values of the bite force. PMID:2489732

Umetsu, N



Comparative evaluation of tensile bond strength of a polyvinyl acetate-based resilient liner following various denture base surface pre-treatment methods and immersion in artificial salivary medium: An in vitro study  

PubMed Central

Background and Aim: This study was formulated to evaluate and estimate the influence of various denture base resin surface pre-treatments (chemical and mechanical and combinations) upon tensile bond strength between a poly vinyl acetate-based denture liner and a denture base resin. Materials and Methods: A universal testing machine was used for determining the bond strength of the liner to surface pre-treated acrylic resin blocks. The data was analyzed by one-way analysis of variance and the t-test (? =.05). Results: This study infers that denture base surface pre-treatment can improve the adhesive tensile bond strength between the liner and denture base specimens. The results of this study infer that chemical, mechanical, and mechano-chemical pre-treatments will have different effects on the bond strength of the acrylic soft resilient liner to the denture base. Conclusion: Among the various methods of pre-treatment of denture base resins, it was inferred that the mechano-chemical pre-treatment method with air-borne particle abrasion followed by monomer application exhibited superior bond strength than other methods with the resilient liner. Hence, this method could be effectively used to improve bond strength between liner and denture base and thus could minimize delamination of liner from the denture base during function.

Philip, Jacob M.; Ganapathy, Dhanraj M.; Ariga, Padma



Massive sublingual hematoma secondary to anticoagulant therapy complicated by a traumatic denture: a case report  

PubMed Central

Introduction Sublingual hematoma secondary to excessive anticoagulation is a rare but potentially fatal condition, and few cases have been documented in the literature. Case presentation We report the case of a 73-year-old Caucasian woman who attended our Accident and Emergency department with massive sublingual hematoma causing superior displacement of the tongue. The condition was found to be the result of an elevated international normalized ratio, further complicated by a traumatic mandibular denture. Conclusions In summary, we recommend the immediate reversal of anticoagulation therapy on admission of patients with severe sublingual hematoma. We further advise surgical decompression/drainage if required and to continue meticulous monitoring. In all cases of early recognition of sublingual hematoma, prompt medical treatment and continuous clinical monitoring is essential, and may prevent the need for a surgical airway procedure.



A comparison between the wear resistance of three types of denture resin to three different dentifrices.  


This study compares the abrasive effects of three dentifrices on three different denture base resins, a heat cured acrylic resin, a self cured acrylic resin and a light activated urethane dimethacrylate-based resin. Specimens of the resins were subjected to a regimen of mechanical brushing using measured amounts of paste on standard toothbrushes driven by a reciprocating device. The apparent wear of each specimen was assessed qualitatively using scanning electron microscopy and quantitatively using profilometry and reflex microscopy. The study showed that cleaning pastes play a significant role in the wear of conventional acrylic resins, the relative abrasivity of the dentifrices being substrate related. However, wear was less evident on the light activated urethane dimethacrylate resin. Brushing with water alone produced no detectable wear on any of the specimens. PMID:9639156

Haselden, C A; Hobkirk, J A; Pearson, G J; Davies, E H



Dietary Carbohydrates Modulate Candida albicans Biofilm Development on the Denture Surface  

PubMed Central

The purpose of this study was to investigate whether dietary carbohydrates can modulate the development of Candida albicans biofilms on the denture material surface. Poly (methyl methacrylate) acrylic resin discs were fabricated and had their surface roughness measured. Biofilms of C. albicans ATCC 90028 were developed on saliva-coated specimens in culture medium without (control) or with carbohydrate supplementation by starch, starch+sucrose, glucose, or sucrose for 72 h. The cell count, metabolic activity, biovolume, average thickness, and roughness coefficient were evaluated at the adhesion phase (1.5 h) and after 24, 48, and 72 h. The secretion of proteinases and phospholipases, cell surface energy, and production of extra/intracellular polysaccharides were analyzed after 72 h of biofilm development. Data were analyzed by one- and two-way ANOVA followed by Tukey’s test at 5% significance level. In the early stages of colonization (adhesion and 24 h), the glucose group showed the highest cell counts and metabolic activity among the groups (p<0.05). After maturation (48 and 72 h), biofilms exposed to glucose, sucrose, or starch+sucrose showed higher cell counts and metabolic activity than the control and starch groups (p<0.001). Compared to the control group, biofilms developed on starch or starch+sucrose had more proteinase activity (p<0.001), whereas biofilms developed on glucose or sucrose had more phospholipase activity (p<0.05). Exposure to starch+sucrose increased the production of extracellular and intracellular polysaccharides (p<0.05). Biofilms developed on starch or without carbohydrate supplementation presented cells with more hydrophobic behavior compared to the other groups. Confocal images showed hyphae forms on biofilms exposed to starch or starch+sucrose. Within the conditions studied, it can be concluded that dietary carbohydrates can modulate biofilm development on the denture surface by affecting virulence factors and structural features.

Santana, Ivone Lima; Goncalves, Leticia Machado; de Vasconcellos, Andrea Araujo; da Silva, Wander Jose; Cury, Jaime Aparecido; Cury, Altair Antoninha Del Bel



An assessment of mast cells and myofibroblasts in denture-induced fibrous hyperplasia.  


OBJECTIVES: The pathogenesis of denture-induced fibrous hyperplasias has not been examined in detail to explain how tissue injury results in fibrous hyperplasia of the oral mucosa. PATIENTS AND METHODS: We examined the presence of mast cells and myofibroblasts in 33 denture-induced fibrous hyperplasias (DIFH) compared with 10 healthy gingival tissues. The parameters examined included mast cell numbers, tissue distribution, degranulation, and cell subtypes using immunohistochemistry. The presence of myofibroblasts and their likely origin was also examined by double immunofluorescense staining. Furthermore, we investigated the synthesis of osteopontin and TGF-?, considered to be involved in the transformation of a fibroblast to a myofibroblast. RESULTS: The results demonstrated that the mast cell numbers are significantly increased in the DIFH compared with non-disease controls. The mast cell localization in lesions was higher in the superficial areas with inflammatory cell infiltration compared with the deep fibrotic area (P < 0.01). The number of tryptase-positive mast cells was significantly higher compared with chymase-positive ones. The TGF-?- or osteopontin-positive cell infiltration into the lesion was found in high numbers. The presence of myofibroblasts was identified in 14 of 33 cases (42%), and some of these cells showed apoptosis when assessed by the TUNEL assay. On the survey of the origin of myofibroblasts, results showed ?SMA and vimentin positivity indicating these transformed from fibroblasts. CONCLUSION: These results are the first to show that mast cells and myofibroblasts can be detected in DIFH, indicating important roles of these cells in the pathogenesis of this lesion. PMID:23627608

Kiuchi, Misa; Yamamura, Takashi; Okudera, Michisato; Souksavanh, Vongsa; Ishigami, Tomohiko; Iwase, Takashi; Warnakulasuriya, Saman; Komiyama, Kazuo



Aesthetic analysis of an implant-supported denture at the cleft area.  


Objective : To evaluate the aesthetics of an implant-supported denture at the cleft area, comparing the peri-implant tissues and prosthetic crown with the contralateral tooth. Settings : Hospital for Rehabilitation of Craniofacial Anomalies, Bauru, São Paolo, Brazil. Patients : A total of 39 individuals of both genders, with complete unilateral cleft lip and palate, who received secondary alveolar bone graft and were rehabilitated with single implant-supported dentures at the area of the missing maxillary lateral incisor after completion of orthodontic treatment. Interventions : The following parameters were analyzed in follow-up sessions: length and width of prosthetic crown and contralateral tooth, characteristics of implants, filling of interproximal space by the papilla, and smile height of the patients. Results : The implant-supported prosthetic crowns were longer than the contralateral tooth (p < .001). Among the 78 papillae analyzed, 29 (37.17%) received a score of 3; 32 (41.02%) papillae had a score of 2; and 17 (21.79%) received a score of 1. Concerning the smile height, among the 39 patients analyzed, 23 (56.41%) had a medium smile, 15 (38.46%) had a high smile, and two (5.12%) presented a low smile. Conclusion : The use of dental implants to rehabilitate the edentulous cleft area is an excellent option. However, adequate evaluation of the bone quantity and quality, positioning and shape of adjacent teeth, smile height, and patient expectations should be considered to achieve success and avoid aesthetic deformities such as elongated teeth and absence of gingival papillae. PMID:22616760

Filho, Jorge Francisco Fiamengui; de Almeida, Ana Lúcia Pompéia Fraga



Temperature rise during intraoral polymerization of self-cured hard denture base liners.  


The aim of this in-vivo study was to evaluate the temperature rise during polymerization of five chairside self-cured hard denture base reliners. For the same patient, 30 identical baseplates, exposing a space on their tissue surface to accommodate the lining material, were made of a light-cured denture base material. A hole was drilled in the center of this area to enable the thermocouple wire of the temperature measuring device to have direct access to the palatal surface of the baseplate. Six baseplates were used for each of the five lining materials tested. Temperature recordings were made every 15 seconds. Data were analyzed using single factor analysis of variance (ANOVA) and the Scheffe's post-hoc analysis for multiple comparisons. The mean maximum temperature values ranged from 40.2 degrees C to 45.7 degrees C being statistically different among the materials (P<0.001). The maximum peak temperature was 53 degrees C and the lowest 39 degrees C. Also the difference between the time each material reached the peak of temperature was statistically significant (P<0.0001). A temperature range of 5.5 degrees C was demonstrated among materials, with the highest polymerization temperatures recorded for Flexacryl Hard and the lowest for Rebase and GC Reline hard. Ufi-gel hard showed the fastest polymerization cycle and was the first to reach the maximum temperature. The available chairside hard liners must be chosen with care considering the thermal effect on the oral mucosa and the discomfort of patient. PMID:20698423

Yannikakis, Stavros; Polychronakis, Nick; Zissis, Alcibiades



Mechanical properties of reinforced denture base resin: the effect of position and the number of woven glass fibers.  


This study examined the effects of the position and the number of woven glass fibers on the flexural strength, flexural modulus, and toughness of reinforced denture base resin. The woven glass fiber consisted of 1-4 laminated sheets. Chemical curing was used to polymerize three types of 4-mm-thick test specimens: fibers in compresrion, fibers in the center, and fibers in tension. Unreinforced specimens were produced as controls. A three-point flexural test was performed and the woven glass fiber content was calculated after the woven glass fiber was fired. The best results were obtained when the woven glass fiber was incorporated outside the base resin under tension, thereby increasing the flexural strength and flexural modulus. Furthermore, the denture base resin reinforced with woven glass fiber was made tougher by increasing the number of woven glass fibers incorporated into the portion under tension. PMID:12474953

Kanie, Takahito; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji



The association between socioeconomic status, oral hygiene practice, denture stomatitis and oral status in elderly people living different residential homes  

Microsoft Academic Search

Oral hygiene practices and denture status of elderly people living in residential homes are different depending on the type of residential homes. In this study the elderly people living in three different residential homes were investigated for this purpose. A total of 269 subjects, 119 males (mean age 73.9±8.8) and 150 females (mean age 78.5±7.2) were involved in this study.

Buket Akalin Evren; Altay Uludamar; Ufuk I?eri; Yasemin Kulak Ozkan



Dynamic Partial Evaluation  

Microsoft Academic Search

Dynamic partial evaluation performs partial evaluation as a side effect of evaluation, with no previous static analysis required.\\u000a A completely dynamic version of partial evaluation is not merely of theoretical interest, but has practical applications,\\u000a especially when applied to dynamic, reflective programming languages. Computational reflection, and in particular the use\\u000a of meta-object protocols (MOPs), provides a powerful abstraction mechanism, providing

Gregory T. Sullivan



[Studies on the flow properties of autopolymerizing hard-setting resins used as direct relining materials for denture bases].  


Autopolymerizing hard-setting direct relining resin is currently being used in dentistry to attain denture bases that conform to the supporting tissues with a high degree of accuracy. The purpose of this study is to investigate the flow of six commercial hard-setting direct relining resins (Denture Liner, Kooliner, New Truliner, Rebaron, Swift, Tokuso Rebase) and several types of impression materials (zinc oxide-eugenol, polysulfide rubber, silicone rubber) using the parallel plate viscometer. The viscometer is used to measure the spread radius of samples (a volume of 0.5 cm3) between two parallel flat plates when a load of 750-gram weight is applied at 1, 10, 60, 100 seconds after loading has begun. In this experiment, the load was applied at 120, 150, 180, 210, 240, 300 seconds after mixing had begun. All the samples were mixed according to the manufacturer's recommendations. The findings were as follows; 1. The flow of the six commercial hard-setting direct relining resins could be compared with one another by the spread radius at 1 second after loading (r1) with no relation to time lapse after initiation of the mix. 2. Denture Liner, Kooliner, Rebaron and Swift had the same flow characteristic when r1 was the same. 3. Polysulfide rubber impression materials had similar flow characteristic to hard-setting direct relining resins. PMID:2489759

Shimoyama, K; Ando, S; Odagiri, K; Nagao, M



Oral Rehabilitation of a Severely Resorbed Edentulous Maxilla with Screwed-retained Hybrid Denture Using Cresco System: A Case Report  

PubMed Central

Due to the angulation of maxillary bone as the maxillary bone resorption occurs from a buccal to palatal direction, bucco-lingually tilted implant placement is more likely especially in the posterior maxilla. The aim of this paper was to present a case restored by using a maxillary hybrid denture using Cresco method. A 59-year-old woman with an edentulous maxilla and five missing mandibular teeth was referred for implant treatment. Six months after sinus lift operation, four mandibular implants and six maxillary implants were placed. Due to the bucco-lingual tilt of two implants, the Cresco method was chosen to fabricate the metal framework for the maxillary hybrid denture that was delivered four months after implant placement. The main advantages of the Cresco method are a perfectly passive framework fit and corrected screw access holes. All ten implants placed were considered successful at 1-year recall, and no screw access holes were seen in the buccal part of the maxillary acrylic teeth. It was concluded that such screw-retained maxillary hybrid denture using the Cresco method met the esthetic expectations of a highly demanding patient.

Turkyilmaz, Ilser; Patel, Neal S.; McGlumphy, Edwin A.



The teaching of denture marking methods in dental schools in the United Kingdom and the United States.  


Forensic organizations worldwide have recommended that dental prostheses should be marked with, at a minimum, the patient's name and preferably with further unique identifiers such as a social security number. The current study aimed to assess the denture marking practice of dental schools within the United States and the United Kingdom. A questionnaire-based survey was employed to gain both quantitative and qualitative data on the methods, practices, and ethos behind denture marking in 14 U.K. and 32 U.S. dental schools. One hundred percent of U.K. and 87.5% of U.S. schools returned surveys and the results suggest that, for dental schools where there is no legal or legislative need for denture marking, the practice is inconsistently taught and appears to be reliant on internal forces within the school to increase awareness. Among those schools practicing marking, only 18% employ a technique likely to withstand common postmortem assaults; this is a concern. PMID:19804522

Richmond, Raymond; Pretty, Iain A



Partial oxidation process  

SciTech Connect

A process is provided for the partial oxidation of a high metals or ash containing liquid hydrocarbonaceous fuel or a slurry of solid carbonaceous fuel to simultaneously produce saturated and unsaturated raw streams of synthesis gas, reducing gas, or fuel gas. Two continuous partial oxidation reactions in two separate reaction zones go on simultaneously. The fuel feed to the first partial oxidation zone is said fresh high metals or ash containing fuel. The raw product gas stream from the first partial oxidation zone is split into first and second split gas streams. The first split gas stream may be cooled in a radiant and/or convection type gas cooler without fouling heat exchange surfaces. The fuel feed to the second partial oxidation zone is a pumpable slurry which is prepared from the entrained matter that is separated from said gas streams during quench cooling and cleaning operations and which contains a comparatively high amount of metals and/or ash. The partial oxidation reaction takes place in the second partial oxidation zone in a reducing atmosphere that includes the second split raw product gas stream from the first partial oxidation zone. By the subject process, there is a reduction in the unconverted carbon produced without any significant loss in efficiency. Further, the life of the cooler for the raw product gas stream is increased.

Jahnke, F. C.



Partial Cavity Drag Reduction  

Microsoft Academic Search

The notion of using air to reduce a ship's frictional drag dates back to the 19^th century. Bubbles, air layers and air filled cavities have been proposed, but there has been little systematic research published. To address this, partial cavity drag reduction experiments were carried out at the W. B. Morgan Large Cavitation Channel. The partial cavity was investigated at

Simo Makiharju; Keary Lay; Ryo Yakushiji; Marc Perlin; Steven Ceccio



Personalization by Partial Evaluation  

Microsoft Academic Search

this paper is to model personalization by the programmatic notion ofpartial evaluation. Partial evaluation is a technique used to automatically specialize programs,given incomplete information about their input. The methodology presented here models a collectionof information resources as a program (which abstracts the underlying schema of organizationand flow of information), partially evaluates the program with respect to user input, and recreatesa

Naren Ramakrishnan; Mary Beth Rosson


Partial update LMS algorithms  

Microsoft Academic Search

Partial updating of LMS filter coefficients is an effective method for reducing computational load and power con- sumption in adaptive filter implementations. This paper presents an analysis of convergence of the class of Sequential Partial Update LMS algorithms (S-LMS) under various assumptions and shows that divergence can be prevented by scheduling coefficient updates at random, which we call the Stochastic

Mahesh Godavarti; Alfred O. Hero III



Effectiveness of Different Cleaning Agents against the Colonization of Candida spp and the in Vitro Detection of the Adherence of These Yeast Cells to Denture Acrylic Surfaces  

PubMed Central

Purpose The aim of this study is to examine the effect Klorhex and Fittydent, which are used as cleaning agents on the adhesion of Candida on the surfaces of acrylic denture and palatal mucosa. In addition, ability of yeasts to adhere to acrylic strips was evaluated after applying these agents in vitro. Materials and Methods Each group of 15 patients cleaned their dentures with either Klorhex or with Fittydent. The control group cleaned their dentures with water. Results It was found that 62.2% of the patients had colonies of Candida species on their palatal mucosa which was reduced to 51.1% after using these cleaning agents. The colonization rate with Candida spp on their dentures was reduces from 82.2% to 68.8% using these cleaning agents. The mean adhesion value of the Candida strains isolated from the acrylic strips were found to be 75 cell/strip prior to applying the Klorhex and Fittydent and 37.5 cell/strip and 15 cell/strip after applying these agents, respectively. Conclusion These results showed that Klorhex and Fittydent have a certain preventive effect on the colonization rate of Candida spp on the surface of these dentures, the palatal mucosa, as well as on the acrylic strips in vitro.

Kalkanci, Ayse; Filiz, Banu; Kustimur, Semra



Partial Torus Instability  

NASA Astrophysics Data System (ADS)

Flux ropes are now generally accepted to be the magnetic configuration of Coronal Mass Ejections (CMEs), which may be formed prior or during solar eruptions. In this study, we model the flux rope as a current-carrying partial torus loop with its two footpoints anchored in the photosphere, and investigate its instability in the context of the torus instability (TI). Previous studies on TI have focused on the configuration of a circular torus and revealed the existence of a critical decay index. Our study reveals that the critical index is a function of the fractional number of the partial torus, defined by the ratio between the arc length of the partial torus above the photosphere and the circumference of a circular torus of equal radius. We refer to this finding the partial torus instability (PTI). It is found that a partial torus with a smaller fractional number has a smaller critical index, thus requiring a more gradually decreasing magnetic field to stabilize the flux rope. On the other hand, the partial torus with a larger fractional number has a larger critical index. In the limit of a circular torus when the fractional number approaches one, the critical index goes to a maximum value that depends on the distribution of the external magnetic field. We demonstrate that the partial torus instability helps us to understand the confinement, growth, and eventual eruption of a flux rope CME.

Olmedo, Oscar; Zhang, J.



Effect of thermocycling on tensile strength and tear resistance of four soft denture liners.  


This study evaluated the effect of thermocycling on the tensile strength and tear resistance of four long-term soft denture liners. One light-activated (Astron Light, AL), two chemically activated (GC Reline Soft, GC; Silagum Comfort, SC), and one heat-cured (Molloplast-B, MLP) soft liner materials were tested. Dumbbell and trouser-leg specimen geometries were used for tensile strength and tear resistance tests, respectively. A total of 120 specimens were prepared. Test specimens for each material (n=5) were subjected to thermal cycling for 1000 and 3000 cycles between 5 degrees C and 55 degrees C in a thermocycler. Before thermocycling, AL gave the lowest tensile strength, while SC exhibited the highest tear resistance value among the materials tested (p < 0.05). Thermal cycling significantly affected the tensile strength of AL as well as the tear resistance values of AL, MLP, and GC materials. This in vitro study revealed that the tensile strength and tear resistance values of the soft liner materials tested varied according to their chemical compositions. PMID:17621948

Oguz, Serra; Mutluay, Mustafa Murat; Dogan, Orhan Murat; Bek, Bulent



Morphological analysis and interleukin release in human gingival fibroblasts seeded on different denture base acrylic resins.  


The development of different types of materials with application in practice dentistry is an area of intense growth and research due to its importance in oral health. Among the diverse materials currently used in restoration or in dentures, the acrylic based resins have been widely employed. The release of toxic components and the changes on their physical and mechanical properties actually represent a goal of intensive research. In vivo analysis showed that the surface roughness of the acrylic resin represents a factor that could stimulate bacteria colonization and soft tissue inflammation. For this purpose, in this work, we have analyzed the cell response to acrylic based resins Ivoclar, Tokuso and Coldpack in basal conditions, unpolished, and after the polished procedure performed to reduce the surface roughness. Our in vitro results using human gingival fibroblasts (HGFs) showed a decrease of cell growth, evaluated by MTT assay starting at 24 h of incubation, in samples seeded on resins in basal conditions and after the polished procedure. This cell growth reduction was associated to evident morphological changes in unpolished materials. After 24 h of culture in presence of polished and unpolished resins a spontaneous release was present of pro-inflammatory cytokines such as interleukin-6 (IL-6) and -8 (IL-8), which was higher in unpolished resins, indicating that the polished procedure, minimizing the cytotoxicity process, could contribute to reduce the gingival inflammation processes. PMID:23058014

Trubiani, O; Toniato, E; Di Iorio, D; Diomede, F; Merciaro, I; D' Arcangelo, C; Caputi, S


Dynamic mechanical properties of oral mucosa: Comparison with polymeric soft denture liners.  


The purpose of this work was to characterize the viscoelastic behaviour of oral mucosa and compare it with the dynamic mechanical properties of different soft liners. For this purpose, a sample of pig oral mucosa and six commercialized soft liner samples have been investigated. A comparison was also carried with the first suitable hard rubber for dental prosthetics: vulcanite. Creep recovery (CR) and dynamic mechanical analysis (DMA) have been used to determine the mechanical modulus of oral mucosa and soft liners respectively. The Poisson ratio is used to compare mucosa bulk modulus and soft liner shear modulus. The biomechanical concept of conventional complete dentures needs a good adjustment of dynamic mechanical impedance between the base and oral mucosa. The viscoelastic mechanical property of the oral mucosa as a referent biopolymer has been confirmed in vitro. The modulus value, adjusted for old patients in physiological conditions, is in the order of 3 MPa. This study underlines the plasticization effect of absorbed water on the mechanical properties of the underlying tissue. This study allows us to define some characteristics of the most adapted biomaterial according to the clinical exigency. The required biomaterial must display the following properties: compatibility and chemical resistance with biological environment perpetuated mechanical properties during physiological conditions and clinical use, good adjustment of dynamic mechanical impedance with supporting mucosa and easy sample processing. PMID:21316614

Lacoste-Ferré, M-H; Demont, Ph; Dandurand, J; Dantras, E; Duran, D; Lacabanne, C



Sorption, Solubility, Bond Strength and Hardness of Denture Soft Lining Incorporated with Silver Nanoparticles  

PubMed Central

The colonization of denture soft lining material by oral fungi can result in infections and stomatitis of oral tissues. In this study, 0 ppm to 200 ppm of silver nanoparticles was incorporated as an antimicrobial agent into composites to reduce the microbial colonization of lining materials. The effect of silver nanoparticle incorporation into a soft lining material on the sorption, solubility, hardness (on the Shore A scale) and tensile bond strength of the composites was investigated. The data were statistically analyzed using two-way ANOVA and Newman-Keuls post hoc tests or the chi-square Pearson test at the p < 0.05 level. An increase in the nanosilver concentration resulted in a decrease in hardness, an increase in sorption and solubility, a decrease in bond strength and a change in the failure type of the samples. The best combination of bond strength, sorption, solubility and hardness with antifungal efficacy was achieved for silver nanoparticle concentrations ranging from 20 ppm to 40 ppm. These composites did not show properties worse than those of the material without silver nanoparticles and exhibited enhanced in vitro antifungal efficiency.

Chladek, Grzegorz; Kasperski, Jacek; Barszczewska-Rybarek, Izabela; Zmudzki, Jaroslaw



Prognosis of partial epilepsy.  

PubMed Central

The prognosis of partial epilepsy in childhood (excluding cases of benign partial epilepsy) was studied; the average follow up period was 7.4 years. Improvement rate of seizure status was 82.3%. We studied favourable prognostic factors and found that those most often associated with seizure improvement were familial convulsions and idiopathic forms, no generalised seizures before partial onset, low frequency of seizures after 12 months of treatment, short duration of epilepsy, and no background activity abnormalities on electroencephalography. We also observed such factors as mental retardation, neurological abnormalities, and behaviour and cognitive disorders. Factors that determined the prognosis for social adjustment were similar to those for seizure improvement. We discuss the favourable prognosis of partial seizures in childhood and the predictive factors.

Porro, G; Matricardi, M; Guidetti, V; Benedetti, P



Clines with partial panmixia  

Microsoft Academic Search

In spatially distributed populations, global panmixia can be regarded as the limiting case of long-distance migration. The effect of incorporating partial panmixia into single-locus clines maintained by migration and selection is investigated. In a diallelic, two-deme model without dominance, partial panmixia can increase or decrease both the polymorphic area in the plane of the migration rates and the equilibrium gene-frequency

Thomas Nagylaki


Partial Rotator Cuff Ruptures  

Microsoft Academic Search

\\u000a Partial rotator cuff ruptures are not rare and occur mainly in the supraspinatus tendon and may extend to that of infraspinatus,\\u000a but rarely to the tendon of subscapularis. Isolated lesions in the tendons of infraspinatus, teres minor or subscapularis\\u000a are rare. Partial ruptures usually occur before the sixth decade of life and can be a cause of unexplained pain in

Antonio Cartucho


Evaluation of shear bond strength of three different types of artificial teeth to heat cure denture base resin: An in vitro study.  


Context: Bonding of artificial teeth and denture base material remained a significant problem for successful prosthetic treatment. Aim: The purpose of this in vitro study was to evaluate shear bond strength of three different artificial teeth with heat cure denture base material after various surface conditioning methods and thermocycling. Materials and Methods: Ninety mandibular first molar denture teeth were selected. They were divided into three groups, Group I: Nanocomposite resin (Veracia), Group II: Composite teeth (Endura), and Group III: Cross-linked acrylic denture teeth (Acry rock). All groups were further subdivided into subgroups based on surface conditioning methods. Subgroup A: No surface conditioning (control group), Subgroup B: Surface conditioning with methyl methacrylate-based bonding agent (Vitacoll), and Subgroup C: Air abrasion with 50 ?m aluminum oxide powder particles plus silane-coupling agent (Monobond-S) and Vitacoll bonding agent. Evaluation of shear bond strength of all the specimens was done using universal testing machine. Results: Mean shear bond strength of Group I, Subgroup B (6.87 ± 0.934) showed higher value when compared with Group II, Subgroup B (6.76 ± 1.84) and Group III, Subgroup B (5.66 ± 2.18). The control group (untreated surface) of all three types of artificial teeth used in this study showed significantly lower shear bond strength values than experimental groups (surface conditioning methods; P < 0.05). Conclusion: The results of this study suggest that there were significant differences in shear bond strength among control group and surface treatment groups of denture teeth bonded to heat cure denture base resin. PMID:24025878

Chittaranjan, B; Taruna, M; Sudheer, N; Patil, Nagesh S


Partial Torus Instability  

NASA Astrophysics Data System (ADS)

Flux ropes are now generally accepted to be the magnetic configuration of coronal mass ejections (CMEs), which may be formed prior to or during solar eruptions. In this study, we model the flux rope as a current-carrying partial torus loop with its two footpoints anchored in the photosphere, and investigate its stability in the context of the torus instability (TI). Previous studies on TI have focused on the configuration of a circular torus and revealed the existence of a critical decay index of the overlying constraining magnetic field. Our study reveals that the critical index is a function of the fractional number of the partial torus, defined by the ratio between the arc length of the partial torus above the photosphere and the circumference of a circular torus of equal radius. We refer to this finding as the partial torus instability (PTI). It is found that a partial torus with a smaller fractional number has a smaller critical index, thus requiring a more gradually decreasing magnetic field to stabilize the flux rope. On the other hand, a partial torus with a larger fractional number has a larger critical index. In the limit of a circular torus when the fractional number approaches 1, the critical index goes to a maximum value. We demonstrate that the PTI helps us to understand the confinement, growth, and eventual eruption of a flux-rope CME.

Olmedo, Oscar; Zhang, Jie




SciTech Connect

Flux ropes are now generally accepted to be the magnetic configuration of coronal mass ejections (CMEs), which may be formed prior to or during solar eruptions. In this study, we model the flux rope as a current-carrying partial torus loop with its two footpoints anchored in the photosphere, and investigate its stability in the context of the torus instability (TI). Previous studies on TI have focused on the configuration of a circular torus and revealed the existence of a critical decay index of the overlying constraining magnetic field. Our study reveals that the critical index is a function of the fractional number of the partial torus, defined by the ratio between the arc length of the partial torus above the photosphere and the circumference of a circular torus of equal radius. We refer to this finding as the partial torus instability (PTI). It is found that a partial torus with a smaller fractional number has a smaller critical index, thus requiring a more gradually decreasing magnetic field to stabilize the flux rope. On the other hand, a partial torus with a larger fractional number has a larger critical index. In the limit of a circular torus when the fractional number approaches 1, the critical index goes to a maximum value. We demonstrate that the PTI helps us to understand the confinement, growth, and eventual eruption of a flux-rope CME.

Olmedo, Oscar; Zhang Jie, E-mail: oolmedo@gmu.ed [Department of Computational and Data Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)



Partially coherent migration  

SciTech Connect

Partially coherent migration reduces the spurious details introduced by velocity macro-model imperfections. In a partially coherent migration, instead of summing coherently over the full aperture to achieve maximum lateral resolution, (1) a coherent stack is performed over a limited window width, and then (2) the collection of coherent stacks for different windows along the full aperture are summed incoherently to produce an amplitude value for each output point. Amplitude accuracy of a migration is improved with some sacrifice in spatial (lateral) resolution. A parameter in partially coherent migration is the running coherent window width, which accounts for the spatial correlation of errors in the velocity model. The coherent window width controls the trade-off between signal-to-noise ratio and lateral resolution. Assuming that timing errors introduced by imperfections of a velocity macro-model are from a zero-mean stationary Gaussian process, partially coherent migration is shown to raise the signal-to-noise ratio of the migrated image as compared to a conventional migration. The two competing aspects of signal-to-noise ratio and lateral resolution of the partially coherent migration in the presence of timing errors are analyzed in a stochastic framework. The intuitively attractive idea of limiting the coherent window width to the correlation length of the timing errors is confirmed numerically.

Lee, D. (Univ. of Pennsylvania, Philadelphia, PA (United States). Medical Image Processing Group, Dept. of Radiology); Jackson, G.M. (Elf Geoscience Research Centre, London (United Kingdom)); Mason, I.M. (Oxford Univ. (United Kingdom))



Magnetic attachment for implant overdentures: influence of contact relationship with the denture base on stability and bending strain.  


This study evaluated how the contact height between the magnetic attachment and denture base influences stability and bending strain. An implant modified with strain gauges and a magnetic attachment mounted in an acrylic resin block were used to characterize systems with varying degrees or heights of contact with the abutment. Bending strain under lateral loading increased significantly as the contact height decreased. In the no contact and resilient contact groups, magnetic assemblies separated at reduced bending strain in all loading conditions. The contact height of the magnetic attachment influenced the stability and the amount of bending strain on the implant. PMID:24179971

Yang, Tsung-Chieh; Maeda, Yoshinobu; Gonda, Tomoya; Wada, Masahiro


Methanol partial oxidation reformer  


A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)



Methanol partial oxidation reformer  


A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)



Oxygen partial pressure sensor  


A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured.

Dees, Dennis W. (Downers Grove, IL)



Oxygen partial pressure sensor  


A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured. 1 fig.

Dees, D.W.



Methanol partial oxidation reformer  


A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

Ahmed, S.; Kumar, R.; Krumpelt, M.



Methanol partial oxidation reformer  


A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

Ahmed, S.; Kumar, R.; Krumpelt, M.



FTC Advertising Substantiation Program. Dental Products Manufacturers. Documentation of Block Drug Company, Inc.  

National Technical Information Service (NTIS)

Documentation is submitted in support of various claims concerning statements that certain foods including apples, peanuts, carrots, steak, corn-on-the-cob, celery, caramels and fried chicken constitute a well-known problem for denture wearers; that regar...



Plural partial associations  

NASA Astrophysics Data System (ADS)

The idea of the Plural Partial Associations is proposed to designate the case of associatability having the prototypes in ordinary life, but not described by the Associative Memory principle. The method based on computation of the correlation functions of the input vector with the back of the reference vectors is discussed as a one of the possible way to realize Plural Partial Associations and neural network model to implement this way is discussed. The possibility of this NN model implementation by two-layered bidirectional optical neural network used the Van der Lught correlator is discussed by the published before theoretical and experimental results.

Pavlov, Alexander V.



Experimental partial epileptogenesis.  


Identification of the responsible mutant genes and of the functional consequences of the mutations in experimental preparations have begun to shed light on mechanisms underlying a rare form of partial epilepsy in humans, autosomal dominant nocturnal frontal lobe epilepsy. Likewise, study of the mechanisms of nongenetic models of a common form of human epilepsy, complex partial epilepsy of temporal lobe origin, has established the hippocampal dentate granule cells as a functional barrier to invasion of epileptiform activity into hippocampus in normal brain; this barrier is defective in an epileptic brain. Potential mechanisms by which the 'barrier function' might become flawed, such as mossy fiber sprouting, are discussed. PMID:10226754

Bausch, S B; McNamara, J O



The effect of denture base surface pretreatments on bond strengths of two long term resilient liners  

PubMed Central

PURPOSE Purpose of this study was to evaluate effect of two surface treatments, sandblasting and monomer treatment, on tensile bond strength between two long term resilient liners and poly (methyl methacrylate) denture base resin. MATERIALS AND METHODS Two resilient liners Super-Soft and Molloplast-B were selected.Sixty acrylic resin (Trevalon) specimens with cross sectional area of 10×10 mm were prepared and divided into two groups of 30 specimens each. Each group was surface treated (n = 10) by sandblasting (250 µ alumina particles), monomer treatment (for 180 sec) and control (no surface treatment). Resilient liners were processed between 2 poly(methyl methacrylate) surfaces, in the dimensions of 10×10×3 mm. Tensile strength was determined with Instron Universal testing machine, at a crosshead speed of 5 mm/min; and the modes of failure (adhesive, cohesive or mixed) were recorded. The data were analyzed using one-way ANOVA, followed by Tukey HSD test (? = 0.05). RESULTS Monomer pretreatment of acrylic resin produced significantly higher bond strengths when compared to sandblasting and control for both resilient liners (P < .001). Sandblasting significantly decreased the bond strength for both the liners when compared to monomer pretreatment and control (P < .001). Mean bond strength of Super-Soft lined specimens was significantly higher than Molloplast-B in various surface treatment groups (P < .05). CONCLUSION Surface pretreatment of the acrylic resin with monomer prior to resilient liner application is an effective method to increase bond strength between the base and soft liner. Sandblasting, on the contrary, is not recommended as it weakens the bond between the two.

Parkhedkar, Rambhau



Reviving Partial Order Planning  

Microsoft Academic Search

This paper challenges the prevailing pessimism about the scalability of partial order planning (POP) algorithms by presenting several novel heuristic control techniques that make them competitive with the state of the art plan syn- thesis algorithms. Our key insight is that the techniques responsible for the efficiency of the currently success- ful planners-viz., distance based heuristics, reachability analysis and disjunctive

Xuanlong Nguyen; Subbarao Kambhampati



Partial observability and learnability  

Microsoft Academic Search

When sensing its environment, an agent often receives information that only partially describes the current state of affairs. The agent then attempts to predict what it has not sensed, by using other pieces of information available through its sensors. Machine learning techniques can naturally aid this task, by providing the agent with the rules to be used for making these

Loizos Michael



Partial trisomy 3q  

Microsoft Academic Search

A new case of partial trisomy 3q is reported in a 5-year-old female with severe congenital malformations and psychomotor retardation. A review of the literature, with a total of 11 patients, allows us to conclude that the clinical picture reminiscent of the Cornelia de Lange syndrome is caused by the trisomic state.

E. Yunis; L. Quintero; A. Castefieda; E. Ramirez; M. Leibovici



Partial Dead Code Elimination  

Microsoft Academic Search

A new aggressive algorithm for the elimination of par- tially dead code is presented, i.e., of code which is only dead on some program paths. Besides being more pow- erful than the usual approaches to dead code elimina- tion, this algorithm is optimal in the following sense: partially dead code remaining in the resulting program cannot be eliminated without changing

Jens Knoop; Oliver Rüthing; Bernhard Steffen



Partial oxidation system  

Microsoft Academic Search

A partial oxidation control system for continuously producing synthesis gas, fuel gas or reducing gas in which one process fuel is replaced by a different fuel without shutting down or depressurizing the gas generator. Suitable burners for introducing the feedstreams into the gas generator comprise a central conduit means radially spaced from a concentric coaxial outer conduit having a downstream

C. P. Marion; A. Brent; E. T. Child; W. B. Crouch; B. Reynolds; G. N. Richter



Sonic Partial Deduction  

Microsoft Academic Search

The current state of the art for ensuring finite unfolding of logic programs consists of a number of online techniques where unfolding decisions are made at specialisation time. Introduction of a static termination analysis phase into a partial deduction algorithm permits unfolding decisions to be made oine, before the actual specialisation phase itself. This separation improves specialisation time and facilitates

Jonathan C. Martin; Michael Leuschel



Partial quantum information.  


Information--be it classical or quantum--is measured by the amount of communication needed to convey it. In the classical case, if the receiver has some prior information about the messages being conveyed, less communication is needed. Here we explore the concept of prior quantum information: given an unknown quantum state distributed over two systems, we determine how much quantum communication is needed to transfer the full state to one system. This communication measures the partial information one system needs, conditioned on its prior information. We find that it is given by the conditional entropy--a quantity that was known previously, but lacked an operational meaning. In the classical case, partial information must always be positive, but we find that in the quantum world this physical quantity can be negative. If the partial information is positive, its sender needs to communicate this number of quantum bits to the receiver; if it is negative, then sender and receiver instead gain the corresponding potential for future quantum communication. We introduce a protocol that we term 'quantum state merging' which optimally transfers partial information. We show how it enables a systematic understanding of quantum network theory, and discuss several important applications including distributed compression, noiseless coding with side information, multiple access channels and assisted entanglement distillation. PMID:16079840

Horodecki, Micha?; Oppenheim, Jonathan; Winter, Andreas



Generalized Partial Indexes  

Microsoft Academic Search

This paper demonstrates the use of generalized par- tial indexes for efficient query processing. We propose that partial indexes be built on those portions of the database that are statistically likely to be the most useful for query processing. We identify three classes of statistical infor- mation, and two levels at which it may be available. We describe indexing strategies

Praveen Seshadri; Arun N. Swami



[Effects of mold preheating temperatures and the time of melt casting on the structure of cast denture frameworks].  


At casting temperatures of 1330 degrees to 1530 degrees C and preheating temperatures of 900 degrees to 1100 degrees C, 28 cast denture frameworks were manufactured using the cobalt chromium alloy Biosil f (Degussa). The inner defects were detected by X-ray defectoscopy and the grain numbers of clasp, connector and basis elements determined by metallography. The best results for compact castings were observed at a temperature range of 1410 degrees to 1480 degrees C. Casting previous to the melting of the last alloy cube results in a structure of clasps and connectors with 100-200 grains/mm2 and a high amount of defects; exceeding the liquidus temperature of 1380 degrees C produces grain numbers of 20-30/mm2, while a casting temperature of 1530 degrees C results in 3-5/mm2. Overheating of the melt, also in connection with low preheating temperatures, is probably a cause for the premature loss of clasp retention and fracture of many denture frameworks. PMID:2700705

Biffar, R; Balz, U



The results of a brief survey of complete denture prosthodontic techniques in predoctoral programs in North American dental schools.  


A brief mail survey of North American dental schools was undertaken to ascertain the current techniques in complete denture prosthodontics regarding preliminary and final impressions, record bases, and denture teeth. Of the 64 schools surveyed, 54 responded (84%). Seventy-four percent of the respondents used only irreversible hydrocolloid (alginate) for their preliminary impressions; 15% used only modeling plastic impression compound. Eighty-one percent used only modeling plastic impression compound for border molding of the final impression tray; 7% used only polyether impression material. Forty-eight percent used only polysulfide rubber (PR) impression material for their final impression material; 4% used only polyether impression material. Only 1 school still used shellac as one of its materials for record bases. Thirty-five percent used only Triad; 35% used only acrylic resin; 24% used both of these materials. Thirteen percent of responding schools used only nonanatomic teeth. The majority (54%) used all three options (nonanatomic, semianatomic, and anatomic). Eleven percent used lingualized occlusion. As compared with a survey performed in 1985, the use of irreversible hydrocolloid as a preliminary impression material, the use of visible light-cured resins for record bases, and the use of anatomic teeth have increased. The use of plastic impression compound for border molding and PR as the final impression material has largely remained the same. PMID:9028228

Arbree, N S; Fleck, S; Askinas, S W



[Analysis of the point-counting and planimetric methods in the quantification of denture biofilm--a methodological validation study].  


Two methods of quantification of the biofilm (point-counting and planimetric) were tested and compared with the paper-weighing method and with the Prosthesis Hygiene Index. The internal surfaces of 62 complete dentures were stained and photographed. The slides were projected on a paper sheet. The total area and the area covered with biofilm were contoured using a black pencil. The point-counting method (experimental 1) was carried out on a mesh of equidistant points. For the planimetric method (experimental 2), the areas of interest were measured by means of a digital planimeter. In the paper-weighing method (control 1) the areas of interest were cut and weighted on a precision scale. In the determination of the Prosthesis Hygiene Index (control 2), the accumulation of biofilm was estimated by means of a scoring method. The results revealed an agreement rate of 82% between the paper-weighing method and the point-counting method, and an agreement rate of 95% between the former and the planimetric method, which was confirmed by high coefficients of correlation (0.98 and 0.99, respectively). The comparison with the Prosthesis Hygiene Index resulted in 55% of agreement with the point-counting method and in 37% of agreement with the planimetric method. The experimental methods can be useful in clinical studies involving the evaluation of the performance of denture cleansers. PMID:11938720

Fernandes, Roseana Aparecida Gomes; Zaniquelli, Osvaldo; Paranhos, Helena de Freitas Oliveira


The Determination of Partial Moments  

Microsoft Academic Search

In statistical decision theory, computations often involve the partial moments of a random variable. Several methods for determining partial moments are discussed, including direct calculation, the use of general formulas which apply to entire families of distributions, and the use of partial moment generating functions. Using these methods, formulas (some involving recursive relationships) are developed for the partial moments of

Robert L. Winkler; Gary M. Roodman; Robert R. Britney



Clinical study of a heat-cured silicone soft lining material.  


Thirty-seven mandibular dentures lined with Molloplast B silicone material were examined after they had been worn for 2-8 weeks and 6, 18 and 30 months. The denture wearers were also examined and interviewed. The colour was found to have become lighter in 46% and turned yellow or brown in 51%; the denture base had worn through in 24% and there was a failure on bond in 22%; no hardening of the material was noted; 24% of the dentures had broken. An unusual taste was reported by 22% and smell by 14% of the denture wearers; mucosal soreness was noted in 14%; denture stomatitis developed in 48%; hygiene was poor in 61% and fungal growth was traced in 81% of the dentures; 73% of the patients were satisfied with the soft lining. PMID:374698

Mäkilä, E; Honka, O



Laparoscopic partial splenic resection.  


Twenty domestic pigs with an average weight of 30 kg were subjected to laparoscopic partial splenic resection with the aim of determining the feasibility, reliability, and safety of this procedure. Unlike the human spleen, the pig spleen is perpendicular to the body's long axis, and it is long and slender. The parenchyma was severed through the middle third, where the organ is thickest. An 18-mm trocar with a 60-mm Endopath linear cutter was used for the resection. The tissue was removed with a 33-mm trocar. The operation was successfully concluded in all animals. No capsule tears occurred as a result of applying the stapler. Optimal hemostasis was achieved on the resected edges in all animals. Although these findings cannot be extended to human surgery without reservations, we suggest that diagnostic partial resection and minor cyst resections are ideal initial indications for this minimally invasive approach. PMID:7773460

Uranüs, S; Pfeifer, J; Schauer, C; Kronberger, L; Rabl, H; Ranftl, G; Hauser, H; Bahadori, K



Partial liquid ventilation.  


Mortality from the adult respiratory distress syndrome (ARDS) and the infant respiratory distress syndrome remains high despite numerous interventions and modalities. Perfluorocarbons (PFC) are inert liquids that can dissolve large amounts of oxygen and carbon dioxide and can be used as respiratory media. Partial liquid ventilation uses PFC to partially fill the lungs of patients with ARDS to improve gas exchange and support them. Studies in animals and humans (mostly neonates) using perflubron, which is currently the only PFC approved for clinical use, have shown that they are safe and effective in improving oxygenation. In this article the rationale of the technique, its historical background, and animal and clinical data to date are reviewed. PMID:16088730

Hadjiliadis, D



Partial oxidation apparatus  

SciTech Connect

An apparatus is described for the simultaneous partial oxidation of a primary fuel stream comprising a high metals or ash containing liquid hydrocarbonaceous fuel or a slurry of solid carbonaceous fuel and a secondary fuel stream to produce a raw gas stream comprising: a vertical cylindrically shaped steel pressure vessel with a coaxial inlet port in the upper end of the vessel and a coaxial outlet port in the lower end of the vessel; a coaxial vertically disposed first gasification burner mounted in the upper inlet port for discharging reactant feedstreams directly into a first vertical coaxial free-flow refractory lined reaction chamber where partial oxidation of the fuel feedstream takes place to produce a first raw gas stream. The bottom of the first reaction chamber is frusto-conical or hemispherical shaped. The apparatus also comprises a coaxial free-flow refractory lined gas diversion chamber with an upper inlet and side and bottom outlets located below the first reaction chamber.

Jahnke, F.C.



Clines with partial panmixia.  


In spatially distributed populations, global panmixia can be regarded as the limiting case of long-distance migration. The effect of incorporating partial panmixia into single-locus clines maintained by migration and selection is investigated. In a diallelic, two-deme model without dominance, partial panmixia can increase or decrease both the polymorphic area in the plane of the migration rates and the equilibrium gene-frequency difference between the two demes. For multiple alleles, under the assumptions that the number of demes is large and both migration and selection are arbitrary but weak, a system of integro-partial differential equations is derived. For two alleles with conservative migration, (i) a Lyapunov functional is found, suggesting generic global convergence of the gene frequency; (ii) conditions for the stability or instability of the fixation states, and hence for a protected polymorphism, are obtained; and (iii) a variational representation of the minimal selection-migration ratio ?(0) (the principal eigenvalue of the linearized system) for protection from loss is used to prove that ?(0) is an increasing function of the panmictic rate and to deduce the effect on ?(0) of changes in selection and migration. The unidimensional step-environment with uniform population density, homogeneous, isotropic migration, and no dominance is examined in detail: An explicit characteristic equation is derived for ?(0); bounds on ?(0) are established; and ?(0) is approximated in four limiting cases. An explicit formula is also deduced for the globally asymptotically stable cline in an unbounded habitat with a symmetric environment; partial panmixia maintains some polymorphism even as the distance from the center of the cline tends to infinity. PMID:22019890

Nagylaki, Thomas



The Partial Past  

Microsoft Academic Search

\\u000a In today’s vision agro-ecosystems of the past may exhibit more stability than they had in reality. Remnants of the past can\\u000a be seen off the main track. They usually boil down to positive mass selection, with some partial resistance involved. Crop\\u000a and cultivar mixtures provided stability. R-gene resistance was found, promoted and exploited. All noses pointed to the same\\u000a direction.

J. C. Zadoks


Partial oxidation process  

Microsoft Academic Search

A continuous process for preventing the build-up of metals from the hydrocarbonaceous fuel feed in a partial oxidation system in which about 80-100 wt. % of the carbon-soot produced is recycled to the gas generator. By the subject process a significantly large portion of the metals and metal compounds i.e. ash in the soot-water feed stream to the decanter become

R. M. Dille; L. E. Estabrook; H. A. Rhodes; G. N. Richter; J. G. P. Rohner



Robotic retroperitoneal partial nephrectomy.  


PURPOSE OF REVIEW: Robotic-assisted renal surgery is being increasingly utilized; however, the majority of these are performed via a transperitoneal approach. Retroperitoneal robotic surgery is a relatively new technique allowing direct access to the posterolateral surface of the kidney, as well as posterior hilar structures. In this review, we summarize the most recent publications and review our experience of robotic retroperitoneal partial nephrectomy. RECENT FINDINGS: The retroperitoneal approach has been successfully applied to robotic partial nephrectomy. The current series find this approach ideal for posterior and lateral renal masses, and technically feasible with the advances in robotic technology. The retroperitoneal approach has been shown to decrease operative times, narcotic need, and permit quicker return of bowel function. Furthermore, there does not appear to be any increase in perioperative complications using this approach. Since 2006, we have treated 68 patients using this approach. The mean age was 58.9 years, and mean preoperative tumor size 2.5 cm (range 1-5 cm). Mean operative and warm ischemia time were 125 min and 20.7 min, respectively. The majority of patients had renal cell carcinoma, with a 4.4 % positive margin rate. The most common complication was an arterial pseudoaneurysm in 3 (4.4 %) patients. The limited data using this technique offer an encouraging outlook on robotic retroperitoneal partial nephrectomy. The retroperitoneal approach permits direct access to the renal hilum, no need for bowel mobilization, and excellent visualization for posteriorly located renal masses. PMID:23404196

Patel, Mayank; Porter, James



Partial Cavity Drag Reduction  

NASA Astrophysics Data System (ADS)

The notion of using air to reduce a ship's frictional drag dates back to the 19^th century. Bubbles, air layers and air filled cavities have been proposed, but there has been little systematic research published. To address this, partial cavity drag reduction experiments were carried out at the W. B. Morgan Large Cavitation Channel. The partial cavity was investigated at Reynolds numbers to 70 million and stable cavities with frictional drag reduction of more than 95% were attained. The model used was a 3 m wide and 12 m long flat plate with a plenum on the bottom. The design of the cavity was based on both linear gravity wave theory and two-dimensional inviscid numerical calculations. To create the partial cavity, air was injected at the base of an 18 cm backwards facing step 1.5 m from the nose of the plate. Frictional loads, free stream speed, air flow and cavity pressures were measured over a range of flow speeds and air fluxes. High speed video was used to investigate the unsteady three dimensional cavity closure. Cloud shedding, similar to sheet-cloud cavitation shedding with natural cavitation on hydrofoils, was observed at the closure.

Makiharju, Simo; Lay, Keary; Yakushiji, Ryo; Perlin, Marc; Ceccio, Steven



Laparoscopic partial splenectomy  

Microsoft Academic Search

Background  The immunologic function of the spleen and its important role in immune defense has led to splenic-preserving surgery. This\\u000a study aimed to evaluate whether laparoscopic partial splenectomy is safe.\\u000a \\u000a \\u000a \\u000a Methods  Data on consecutive patients presenting with localized benign or malignant disease of the spleen were included in a prospective\\u000a database. The surgical technique consisted of six steps: patient positioning and trocar

S. Uranues; D. Grossman; L. Ludwig; R. Bergamaschi



[Partial trisomy 18q].  


Authors present a new case with partial trisomy for long arms of chromosome 18(q12-qter) resulting from a balanced translocation t(4;18) on her mother. Comparing clinical features of our patient with that of other reported cases with the same trisomic segment, we can deduce that most important characteristics on this syndrome are: psychomotor and grow retardation, congenital heart disease, dolicocephaly, low set and malformed ears, micrognathia, short neck with redundant skin and a longer survival than in total trisomy 18. PMID:3631780

Darnaude, M T; López Pajares, I; Delicado, A; García Frias, E



Partial Triceps Disruption  

PubMed Central

Partial triceps tendon disruptions are a rare injury that can lead to debilitating outcomes if misdiagnosed or managed inappropriately. The clinician should have a high index of suspicion when the mechanism involves a fall onto an outstretched arm and there is resultant elbow extension weakness along with pain and swelling. The most common location of rupture is at the tendon-osseous junction. This case report illustrates a partial triceps tendon disruption with involvement of, primarily, the medial head and the superficial expansion. Physical examination displayed weakness with resisted elbow extension in a flexed position over 90°. Radiographs revealed a tiny fleck of bone proximal to the olecranon, but this drastically underestimated the extent of injury upon surgical exploration. Magnetic resonance imaging is essential to ascertain the percentage involvement of the tendon; it can be used for patient education and subsequently to determine treatment recommendations. Although excellent at finding associated pathology, it may misjudge the size of the tear. As such, physicians must consider associated comorbidities and patient characteristics when formulating treatment plans.

Foulk, David M.; Galloway, Marc T.



Finite element analysis to compare stress distribution of connector of lithia disilicate-reinforced glass–ceramic and zirconia-based fixed partial denture  

Microsoft Academic Search

This study used finite element method to analyze the stress distribution in connector of ceramic-based bilayer structures,\\u000a in simulation of dental crown-like structures with a functional but weak veneer layer bonded onto a strong core layer. The\\u000a purpose of this study was to evaluate the stress distribution at veneer\\/core interface of 2 different core materials [Yttria-stabilized\\u000a tetragonal zirconia polycrystals (Y-TZP)

Jie Lin; Akikazu Shinya; Harunori Gomi; Akiyoshi Shinya


Repair of a multiple implant-supported fixed superstructure with a metal-ceramic resin-bonded fixed partial denture: A clinical report.  


Abstract Even in the case of implant loss, re-placement of the implant and re-fabrication of the superstructure are often sufficient, as long as the bone and soft tissue are in good condition. However, if implant loss accompanied by serious bone resorption occurs with a fixed implant superstructure supported by multiple implants, it is very difficult to treat. This clinical report is to describe the process by which a multiple implant-supported fixed metal ceramic restorations were repaired with a metal ceramic resin bonded FPD (MC RBFPD) without complete re-fabrication following removal of one of the implants due to severe bone resorption. The 3-year follow-up indicated excellent serviceability and a well-satisfied patient. PMID:22506800

Hagiwara, Yoshiyuki; Narita, Tatsuya; Araki, Masao; Sawada, Kunihiko; Nakajima, Kiyoshi



The effect of the addition of different fibres on the transverse and impact strength of acrylic resin denture base material.  


The aim of the present study was to investigate the effect of the addition of different types of fibres on the transverse and impact strength of acrylic resin denture base material. The addition of glass fibres (strand) and polyethylene fibres produced a non significant increase in the modulus of elasticity, compared with the control of conventional heat-cured acrylic resin. The addition of glass fibres (woven and strand), polyethylene and carbon fibres to acrylic resin produced a non significant increase in the modulus of rupture. The addition of carbon, glass (strand) and polyethylene fibres produced a significant increase in the impact strength. Within the limitations of this study the addition of silk fibres did not produce an improvement in the mechanical properties. PMID:12868211

Rahamneh, A; Jagger, D C; Harrison, A



Partial polaroids in birefringent filters  

Microsoft Academic Search

It is demonstrated that a single partial polaroid in a Lyot filter behaves in much the same manner as a contrast element. Use of a partial polaroid with a transmission ratio of 10 to 1 results in a factor of 10 decrease in the principal secondary maxima. An explanation of the effect of the partial polaroids is presented in terms

Lockheed Rye



Partial Evaluation Using Dependence Graphs  

Microsoft Academic Search

This thesis describes the use of program dependence graphs, as opposed to control flow graphs, as the basis for the partial evaluation of imperative programs. Partial evaluation is a program specialization operation in which programs with multiple inputs are specialized to take into account known values for some of their inputs. Thus, the result of partially evaluating a program given

Manuvir Das



Partial gastrectomy for haemorrhage  

PubMed Central

An analysis was made of the results of 566 partial gastrectomies for haemorrhage from gastroduodenal ulceration between 1953 and 1962 with regard to mortality, morbidity, and long-term follow up. With rigid criteria for selection of patients for surgery, the overall mortality rate for ulcerative gastroduodenal haemorrhage was 8·6%. The actual operative mortality rate more than doubles if an emergency operation is performed later than four days after the patient's admission with haemorrhage. Postoperative and later bleeding complications occurred in 5% of patients. Regardless of the length of ulcerative history, over 92% of patients have clinically satisfactory long-term results. Six per cent required further operation, after which, they too had clinically satisfactory results.

Cocks, J. R.; Desmond, A. M.; Swynnerton, B. F.; Tanner, N. C.



Effect of surface preparation on the bond strength of heat-polymerized denture base resin to commercially pure titanium and cobalt-chromium alloy.  


The aim of this study was to investigate the bond durability of heat-polymerized denture base resin to cast CP Ti and Co-Cr alloy. The alloy specimens were divided into five groups: 1) airborne-particle abraded with 50 µm alumina (SAND), 2) Rocatec tribochemical silica coating system (RO), 3) air-abraded followed by application of Epricord Opaque Primer (EP), 4) air-abraded followed by application of Super Bond C&B liquid (SB), 5) air-abraded followed by application of Alloy Primer (AL). Heat-polymerized denture resin was applied to the bonding area and polymerized according to the manufacturer's instructions. The halves of all specimens were thermocycled up to 10,000 cycles. Before thermocycling SB and AL showed significantly higher shear bond strengths than SAND, RO, EP for both metals. The shear bond strength of AL group after thermocycling was significantly higher than that of the other groups. PMID:21383520

Kawaguchi, Tomohiro; Shimizu, Hiroshi; Lassila, Lippo V J; Vallittu, Pekka K; Takahashi, Yutaka



In Vitro Activities of New Triazole Antifungal Agents, Posaconazole and Voriconazole, Against Oral Candida Isolates from Patients Suffering from Denture Stomatitis  

Microsoft Academic Search

Denture stomatitis is often treated with antifungal agents but recurrences or new episodes are common, and certain episodes\\u000a can be resistant. New triazoles, such as posaconazole and voriconazole, may represent useful alternatives for management.\\u000a In vitro activities of amphotericin B, nystatin, miconazole, fluconazole, itraconazole, posaconazole and voriconazole against\\u000a 150 oral Candida (101 C. albicans, 18 C. tropicalis, 12 C. glabrata,

Cristina Marcos-Arias; Elena Eraso; Lucila Madariaga; Alfonso Javier Carrillo-Muñoz; Guillermo Quindós


[Clinical and laboratory studies of bacterial adhesion to validate the choice of material for making provisional dentures for patients with periodontal diseases].  


Adhesion of bacteria favoring the development of oral inflammations, including cariesogenic and periodontopathogenic (Actinobacillus actinomycetemcommitans, Streptococcus sanguis, Fusobacterium nucleatum, Staphylococcus warneri) and yeast fungi (Candida albicans), to 13 materials used for making provisional dentures was studied. Adhesion of all the studied bacteria and fungi to Russian material Esterfil Foto was the minimum. Clinical use of this material in patients with chronic generalized periodontitis showed that it was well tolerated and the treatment led to improvement of oral microbiocenosis. PMID:12056141

Ibragimov, T I; Arutiunov, S D; Tsarev, V N; Lebedenko, I Iu; Kraveishvili, S E; Trefilov, A G; Arutiunov, D S; Lomakina, N A



Partial oxidation process  

SciTech Connect

This patent describes an improvement in a process for the partial oxidation of an ash-containing heavy liquid hydrocarbonaceous fuel, an ash-containing solid carbonaceous fuel, or mixtures thereof to produce an effluent gas stream having a temperature in the range of about 2000{degrees}F to 3000{degrees}F and comprising H{sub 2} + CO and entrained molten slag and ash; and cooling the effluent gas stream by passing the gas stream in succession through a radiant cooling zone, a metal gas transfer line with internal metal heat transfer surfaces, and a convection cooling zone. The improvement involves preventing the molten slag and ash from sticking to the metal heat transfer surfaces on the inside of the gas transfer line comprising: cooling the internal metal heat transfer surfaces of the metal gas transfer line where high gas turbulence occurs to a temperature in the range of about 150{degrees}F to below 700{degrees}F by noncontact heat exchange with a coolant.

Jahnke, F.C.



Partial lipodystrophy in coeliac disease.  

PubMed Central

The association of coeliac disease and partial lipodystrophy is described. The patient also had deficiencies of serum IgA and C3 complement (the latter associated with partial lipodystrophy). In addition, there was subclinical dermatitis herpetiformis confirmed by skin biopsy. The facial wasting of fully developed partial lipodystrophy may be misinterpreted as a sign of malabsorption but the facial, upper limb, and truncal lipodystrophy contrasts with normal pelvic and lower limb appearances. Images Figure 1 Figure 2

O'Mahony, D; O'Mahony, S; Whelton, M J; McKiernan, J



Genetics of human partial epilepsy.  


A minor genetic predisposition to partial epilepsy has been long recognized. Recently, a group of idiopathic partial epilepsies with autosomal dominant inheritance has been identified. The clinical features and molecular genetic findings in these epilepsies are outlined in the present review. The first genetic defect in an idiopathic epilepsy has been found in autosomal dominant nocturnal frontal lobe epilepsy, the archetype of this newly recognized group of inherited partial epilepsies. PMID:9146992

Berkovic, S F; Scheffer, I E



Trigonometric Integrals via Partial Fractions  

ERIC Educational Resources Information Center

|Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.|

Chen, H.; Fulford, M.



The effect of mechanical and chemical polishing techniques on the surface roughness of denture base acrylic resins  

PubMed Central

Smooth polished surface of dental prostheses is important to prevent bacterial colonization and plaque accumulation. The acrylic base of prosthodontic appliances needs to be adjusted by grinding which often alters the surface of the denture base. It is therefore important to know how different polishing techniques affect surface roughness of acrylic resin. Objective The aim of this study was to evaluate the effect of mechanical polishing (MP) and chemical polishing (CP) on the surface roughness of heat cured (HC) and auto cured (AC) denture base acrylic resins. Materials and methods Sixty acrylic resin specimens (30 × 15 × 3 mm) were made for each of the two types of acrylic resins. Thirty HC specimens received mechanical conventional lathe polishing using cone with pumice slurry and soft brush with chalk powder. The other thirty HC specimens received chemical polishing by immersing in methyl-methacrylate monomer heated to 75 °C ± 1 °C for 10 s. The sixty AC specimens received mechanical and chemical polishing in the same manner. Surface roughness was measured using surface analyzing instrument in microns. The data were statistically analyzed by two-way analysis of variance (ANOVA) followed by post hoc Tukey’s test (? = 0.05). Results The surface roughness mean in microns in order of decreasing values were: CP-HC: 1.4132 ?m; CP-AC: 1.3494 ?m; MP-AC: 0.7364 ?m and MP-HC: 0.6333 ?m. Two-way ANOVA revealed that the MP-HC was significantly different from CP-HC and CP-AC (P < 0.05). The MP-AC is also significantly different from CP-HC and CP-AC (P < 0.05). There was no significant difference between MP and CP of HC and AC acrylic resin groups. Conclusion It can be concluded that MP produced significantly smoother surfaces than CP. The surface roughness obtained by MP was not influenced by acrylic resin type where as this was not true for CP.

Al-Rifaiy, Mohammed Q.



C++ Templates as Partial Evaluation  

Microsoft Academic Search

This paper explores the relationship between C++ templates and partial evaluation. Templates were designed to support generic programming, but unintentionally provided the ability to perform compile-time computations and code generation. These features are completely accidental, and as a result their syntax is awkward. By recasting these features in terms of partial evaluation, a much simpler syntax can be achieved. C++

Todd L. Veldhuizen



Ocular bacterial flora in contact lens wearers  

Microsoft Academic Search

In this study, ocular bacterial flora was determined for 126 healthy subjects before and after wearing soft contact lenses for 3, 6, and 9 months. The lenses were polyhydroxyethyl methacrylate with a water content of 55%. The care system used polyaminopropyl biguinide as the preservative.Our results indicate the presence of microorganisms such as Staphylococcus epidermidis (40.03%), Corynebacterium xerosis (2.78%), Corynebacterium

Josefa Velasco Cabrera; Javier Bermúdez Rodriguez



[Topamax monotherapy of partial epilepsy].  


Thirty patients diagnosed with partial epilepsy (PE): 17 cases with cryptogenic PE, 11--with symptomatic PE and 2--with symptomatic generalized PE, have been switched to topamax monotherapy, in dosage 50-200 mg daily, for 3 months. A type of seizures--simple partial, complex partial and secondary generalized, was taken into account, when considering topamax efficacy. A complete elimination of seizures was achieved after 3 months treatment in 80% of the cases, the mostly pronounced effect being demonstrated for secondary generalized seizures. A decrease of seizures frequency was shown for all types, but in simple partial and secondary generalized seizures the effect emerged earlier (after 1 month of the treatment) comparing to complex partial seizures. Good tolerability of topamax was observed. PMID:15347032

Kalinin, V V; Zheleznova, E V; Sokolova, L V; Rogacheva, T A; Polianski?, D A; Zemlianaia, A A



High Productivity Implantation ``PARTIAL IMPLANT''  

NASA Astrophysics Data System (ADS)

The patterned ion implantation ``PARTIAL IMPLANT'' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is ``DIVIDE PARTIAL IMPLANT,'' that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is ``RING PARTIAL IMPLANT'' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao



The effect of oral commensal bacteria on candidal adhesion to denture acrylic surfaces. An in vitro study.  


The effect of four different species of oral bacteria (Streptococci (X 2); Escherichia; Porphyromonas) on the adhesion of Candida albicans and Candida krusei to denture acrylic surfaces was studied using a previously described in vitro adhesion assay. Clear acrylic strips immersed in known concentrations of bacterial suspensions and incubated for 45 min to 1 h, at 37 degrees C, were transferred to yeast suspensions of known concentrations and incubated for a similar period, and the adherent yeasts were quantified using an image analysis system. Pre-exposure to different bacterial concentrations resulted in suppression of candidal adhesion to varying degrees. Of three selected concentrations, exposure to the highest bacterial concentration (10(6) organisms/ml) resulted in a consistent reduction in candidal adhesion, except for E. coli-C. albicans and S. salivarius-C. albicans combinations. Candidal adhesion was significantly reduced on pre-exposure to S. sanguis and P. gingivalis, but not E. coli. There were also significant differences in relative adhesion between C. albicans and C. krusei. Taken together, these results indicate that the adhesion of yeasts to acrylic strips is modulated both by the quantity and the quality of pre-existing bacterial flora on acrylic surfaces. PMID:8703439

Nair, R G; Samaranayake, L P



Team-based learning in a preclinical removable denture prosthesis module in a United Arab Emirates dental school.  


The purpose of this article is to describe the implementation of a team-based learning (TBL) approach in a removable denture prosthesis (RDP) module and present the results of students' performance in individual and group TBL activities and exam scores, students' experience with TBL and end of course evaluations, and faculty feedback. Course material at the College of Dentistry, University of Sharjah, United Arab Emirates, was transformed into seven conventional lectures and seven TBL sessions. Each TBL session consisted of pre-assigned reading (self-directed learning), in-class individual and group readiness tests (accountability), team problem-solving of patient RDP cases, and faculty-led class discussion (knowledge application). The course was assessed through scores from TBL session activities and course examinations, student satisfaction survey, and faculty feedback. Course grades were found to be higher using the TBL method then the traditional lecture-based method. Student evaluation data and faculty response indicated strong support for TBL as it was implemented in the course. The faculty noted a higher level of student engagement with team learning than in conventional class lecturing. TBL is an active-learning instructional strategy for courses with high student-to-faculty ratios. This approach provides regular feedback and the opportunity for students to develop higher reasoning skills. PMID:23486901

Haj-Ali, Reem; Al Quran, Firas



Efficient Inference of Partial Types  

Microsoft Academic Search

Partial types for the ?-calculus were introduced by Thatte in 1988 (3) as a means of typing objects that are not typable with simple types,such as heterogeneous lists and persistent data. In that paper he showed that type inference for partial types was semidecidable. Decidability remained open until quite recently,when O'Keefe and Wand (2) gave an exponential time algorithm for

Dexter Kozen; Jens Palsberg; Michael I. Schwartzbach