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1

Cleft lip and palate management with maxillary expansion and space opening for a single tooth implant.  

PubMed

An adult Class I malocclusion with a unilateral cleft lip and palate is presented. The maxillary transverse deficiency was managed with orthopedic expansion and the missing lateral incisor with space opening, bone grafting, and single tooth implant. The mild maxillary retrognathia and deficient lip support was managed with dental compensation. PMID:10672214

Sabri, R

2000-02-01

2

Esthetic option for the implant-supported single-tooth restoration -- treatment sequence with a ceramic abutment.  

PubMed

A single implant-supported restoration is one treatment alternative to consider for the replacement of a missing tooth. Technological advances in materials and machining have led to the development of a densely sintered aluminum oxide ceramic abutment, designed and machined using CAD/CAM technology. This manufacturing method improves management of the subgingival depth of the crown/abutment interface and enhances the esthetic qualities of the restoration. However, since this ceramic abutment has less mechanical resistance than metal abutments, its use should be confined to the restoration of incisors and premolars not subjected to excessive occlusal forces. PMID:11597342

Boudrias, P; Shoghikian E; Morin E; Hutnik, P

2001-10-01

3

Clinical Outcome of Inter-Proximal Papilla between a Tooth and a Single Implant Treated with CAD/CAM Abutments: a Cross-Sectional Study  

PubMed Central

ABSTRACT Objectives The aim of this study was to assess the clinical outcomes achieved with Computer-Assisted Design/Computer-Assisted Manufacturing implant abutments in the anterior maxilla. Material and Methods Nineteen patients with a mean age of 41 (range form 26 to 63) years, treated with 21 single tooth implants and 21 Computer-Assisted Design/Computer-Assisted Manufacturing (CAD/CAM) abutments in the anterior maxillary region were included in this study. The patients followed 4 criteria of inclusion: (1) had a single-tooth implant in the anterior maxilla, (2) had a CAD/CAM abutment, (3) had a contralateral natural tooth, (4) the implant was restored and in function for at least 6 months up to 2 years. Cases without contact point were excluded. Presence/absence of the interproximal papilla, inter tooth-implant distance (ITD) and distance from the base of the contact point to dental crest bone of adjacent tooth (CPB) were accessed. Results Forty interproximal spaces were evaluated, with an average mesial CPB of 5.65 (SD 1.65) mm and distal CPB of 4.65 (SD 1.98) mm. An average mesial ITD of 2.49 (SD 0.69) mm and an average distal ITD of 1.89 (SD 0.63) mm were achieved. Papilla was present in all the interproximal spaces accessed. Conclusions The restoration of dental implants using CAD/CAM abutments is a predictable treatment with improved aesthetic results. These type of abutments seem to help maintaining a regular papillary filling although the variations of the implant positioning or the restoration teeth relation. PMID:24422016

Lima, Tiago; Carvalho, Ágata; Carvalho, Vasco

2012-01-01

4

Ankylosed maxillary incisor with severe root resorption treated with a single-tooth dento-osseous osteotomy, vertical alveolar distraction osteogenesis, and mini-implant anchorage.  

PubMed

Dentoalveolar ankylosis interferes with the vertical growth of the alveolar process, which can lead to an open bite, an unesthetic smile, and occlusal disharmony. This case report presents a new treatment protocol for an ankylosed tooth with severe root resorption using a combined surgical orthodontic management protocol involving a single-tooth dento-osseous osteotomy and vertical alveolar distraction osteogenesis with intraoral elastics and mini-implant anchorage. After distraction and active orthodontic treatment, the patient's anterior open bite was corrected. A Class I dental relationship was achieved, overjet was decreased, and a normal incisor relationship was obtained. PMID:25172260

Sen???k, Neslihan Ebru; Koçer, Gülperi; Kaya, Bulem Üreyen

2014-09-01

5

A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla  

PubMed Central

Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P < 0.041) compared to fresh surgical extraction sockets (P < 0.540). Significant MBL was observed on the mesial side of the implant after cementation of the provisional (P < 0.007) and after 12 months (P < 0.034) compared to the distal side which remained stable for 3 and 5 years observation period. Conclusions: Within the limitations of this study, responses of local bone to immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites. PMID:24550840

Berberi, Antoine N.; Sabbagh, Joseph M.; Aboushelib, Moustafa N.; Noujeim, Ziad F.; Salameh, Ziad A.

2014-01-01

6

Clinical success of implant-supported and tooth-implant-supported double crown-retained dentures.  

PubMed

The objective of this retrospective study was to compare biological and technical complications of implant-supported and tooth-implant-supported double crown-retained dentures (DCRDs) with those of tooth-supported DCRDs. Sixty-three DCRDs were monitored. One study group included 16 prostheses with a combination of implants and natural teeth as double crowns (ti group), whereas in the second study group, 19 dentures were retained exclusively on implants (ii group); a third study group with 28 exclusively tooth-supported dentures served as controls (tt group). Tooth loss, implant failure, and technical complications (loss of retention of primary crown, abutment screw loosening, loss of facing, fracture of resin denture teeth and fracture of saddle resin) were analysed. During the observation period of 24 months, no implants or teeth were lost in the ti group and three technical complications were recorded. In the ii group, two implants were lost, two cases of peri-implantitis occurred and four technical complications were observed. In the tt group, two cases of tooth loss and seven technical complications were observed. At the time of the last examination, all prostheses of the ti group and the ii group were functional. Patients of these two study groups reported high satisfaction with both function and aesthetics with no significant difference between the two groups. Treatment with DCRDs showed comparable results in the three study groups. The 2-year results indicate that double crowns can be recommended for implant and combined tooth-implant-retained dentures. PMID:21789591

Bernhart, Gunda; Koob, Andreas; Schmitter, Marc; Gabbert, Olaf; Stober, Thomas; Rammelsberg, Peter

2012-08-01

7

Prognosis and evaluation of tooth damage caused by implant fixtures.  

PubMed

Damage to adjacent teeth is one of the various complications that may occur during implant placement and is often the result of improper direction during fixture placement or excessive depth of placement. In general, if detrimental symptoms, such as reaction to percussion in damaged teeth, mobility, and pulp necrosis, are not present, osseointegration should be observed at follow-up. In three cases, the possibility of root damage due to an implant fixture placed too close to each adjacent tooth was perceived on radiographs. However, in all of these cases, there were no clinical symptoms or radiographic changes present in the tooth, and the implants did not exhibit decreased stability or peri-implantitis. Therefore, we can carefully predict that the implant fixture close to the adjacent tooth did not invade the cementum of the root, and therefore did not produce the suspected pulpal damage or periradicular symptoms. In this study, we considered both the implant status as well as the adjacent tooth. PMID:24471033

Yoon, Wook-Jae; Kim, Su-Gwan; Jeong, Mi-Ae; Oh, Ji-Su; You, Jae-Seek

2013-06-01

8

Prognosis and evaluation of tooth damage caused by implant fixtures  

PubMed Central

Damage to adjacent teeth is one of the various complications that may occur during implant placement and is often the result of improper direction during fixture placement or excessive depth of placement. In general, if detrimental symptoms, such as reaction to percussion in damaged teeth, mobility, and pulp necrosis, are not present, osseointegration should be observed at follow-up. In three cases, the possibility of root damage due to an implant fixture placed too close to each adjacent tooth was perceived on radiographs. However, in all of these cases, there were no clinical symptoms or radiographic changes present in the tooth, and the implants did not exhibit decreased stability or peri-implantitis. Therefore, we can carefully predict that the implant fixture close to the adjacent tooth did not invade the cementum of the root, and therefore did not produce the suspected pulpal damage or periradicular symptoms. In this study, we considered both the implant status as well as the adjacent tooth. PMID:24471033

Yoon, Wook-Jae; Jeong, Mi-Ae; Oh, Ji-Su; You, Jae-Seek

2013-01-01

9

Hydroxyapatite-coated tooth implants by laser  

NASA Astrophysics Data System (ADS)

Thin films of biocompatible ceramic were fabricated by pulsed laser deposition on cylindrical implants. Diamond- like carbon films were deposited in vacuum on titanium alloy prostheses, heated to 90 degrees C. Coated prostheses were implanted into legs of rats and osseointegration higher than 60 percent was determined. Thin films of hydroxyapatite were created on real dental implants at 500 degrees C in Ar-water vapor atmosphere. Coated implants were implanted into mandibula of minipigs to study load free osseointegration. Results and experiences are presented and discussed.

Jelinek, Miroslav; Dostalova, Tatjana; Himmlova, Lucia; Grivas, Christos

1996-09-01

10

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. PMID:23255882

Calvani, Pasquale; Hirayama, Hiroshi

2012-01-01

11

Orthodontic single tooth intrusion with a removable interocclusal device: A clinical report.  

PubMed

Interdisciplinary therapy was used to treat a patient missing a single posterior tooth opposing an extruded tooth. The simple technique used a removable interocclusal device and elastic band for orthodontic intrusion over a 2-month period after implant placement in the opposing arch to aid in prosthetic site development. This approach was designed to increase the interocclusal space needed to restore the implant, obtain a more consistent occlusal plane, and improve esthetics. Clinical and radiographic examinations at the 6-month follow-up revealed an acceptable occlusal relationship and improved esthetic appearance that was achieved with the documented course of treatment. PMID:23684276

Slighly, Corey; Ramos, Van; Brousseau, Steve

2013-05-01

12

Autogenous tooth transplantation for replacing a lost tooth: case reports  

PubMed Central

The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site. PMID:23493816

Kang, Ji-Youn; Chang, Hoon-Sang; Hwang, Yun-Chan; Hwang, In-Nam; Oh, Won-Mann

2013-01-01

13

Single tooth tells us the date of birth.  

PubMed

The atmospheric carbon-14 ((14)C) concentration remained relatively stable until 1955, but then rapidly increased after 1955 by nuclear bomb tests, peaked in 1963, and decreased thereafter. Recently, Spalding et al. proposed epoch-making method for determining date of birth (DOB) using the tooth enamel (14)C incorporated during enamel formation. However, because the (14)C level analyzed in one tooth gives two possible age ranges (up-slope or down-slope of the bomb curve), a variety of teeth that formed in different periods are required for estimating DOB in this method. Enamel formation in a tooth moves from the incisal (occlusal) side to the cervical side. Taking advantage of this characteristic, we have first succeeded in specifying the age range from only single tooth by measuring (14)C in the incisal (occlusal) and cervical regions of the enamel separately. To date, no method of determining DOB or age estimation from single tooth enamel has been made. Furthermore, this method of dividing tooth into smaller parts could be useful for producing a more accurate DOB. Our new method is a powerful tool for identification when we can use only extremely few specimens in forensic casework. PMID:20953875

Kondo-Nakamura, Mihoko; Fukui, Kenji; Matsu'ura, Shuji; Kondo, Megumi; Iwadate, Kimiharu

2011-11-01

14

An Investigation of Three types of Tooth Implant Supported Fixed Prosthesis Designs with 3D Finite Element Analysis  

PubMed Central

Objective: Tooth/implant supported fixed prostheses may present biomechanical design problems, as the implant is rigidly anchored within the alveolus, whereas the tooth is attached by the periodontal ligament to the bone allowing movement. Many clinicians prefer tooth/implant supported fixed prosthesis designs with rigid connectors. However, there are some doubts about the effect of attachment placement in different prosthesis designs. The purpose of this study was to examine the stresses accumulated around the implant and natural teeth under occlusal forces using three dimensional finite element analysis (3D FEA). Materials and Methods: In this study, different connection designs of tooth/implant fixed prosthesis in distal extension situations were investigated by 3D FEA. Three models with various connection designs were studied; in the first model an implant rigidly connected to an abutment, in the second and third models an implant connected to abutment tooth with nonrigid connector in the distal part of the tooth and mesial part of the implant. In each model, a screw type implant (5×11mm) and a mandibular second premolar were used. The stress values of these models loaded with vertical forces (250N) were analyzed. Results: There was no difference in stress distribution around the bone support of the implant. Maximum stress values were observed at the crestal bone of the implant. In all models, tooth movement was higher than implant movement. Conclusion: There is no difference in using a rigid connector, non rigid connector in the distal surface of the tooth or in the mesial surface of an implant. PMID:23724203

Koosha, Sara; Mirhashemi, Fatemeh Sadat

2013-01-01

15

Alveolar Cleft Restoration Using Autogenous Tooth Bone Graft Material for Implant Placement: A Case Report.  

PubMed

Abstract The aim of this case report is to show the effectiveness of using autogenous tooth bone (AutoBT) graft material in an alveolar cleft restoration for implant placement and integration. This is one of the first reported cases using AutoBT as a graft material in repairing an alveolar cleft defect. A 19 year-old Korean male patient with a history of cleft lip and palate received an alveolar cleft restoration with AutoBT after extracting an impacted right maxillary lateral incisor. AutoBT was made from mandibular third molars of this patient. Subsequently, an implant fixture (Astra Tech AB, Mölndal, Sweden) 3 mm in diameter and 11 mm in length was placed with an initial locking torque of 45 Ncm. Stable implant restoration was achieved in an alveolar defect site. PMID:24295451

Jeong, Kyung-In; Lee, Junho; Um, In-Woong; Kim, Young-Kyun

2013-12-01

16

Tooth movement using palatal implant supported anchorage compared to conventional dental anchorage.  

PubMed

Tooth stability is one of the most changing parameters in age. The aim of the present study has been to clarify the therapeutic benefit of the osseointegrated palatal implant (PI) supported anchorage in adolescents compared with conventional dental anchorage (DA) in extraction cases requiring 'maximum anchorage' in growing patients following the post pubertal growth spurt. Thirty patients (14.22±1.37 years) selected with homogeneous facial skeletal characteristics were divided in two groups. In the PI group, Orthosystem(®) implants were placed into the palate for anchorage and the transpalatal arch (TPA) was fixed to the implant and to the molar bands. In the DA group maximal anchorage was provided by a TPA and a utility arch. Super-elastic spring was used for canine- and contraction arch for incisor retraction. An insignificant difference was observed between the groups as to the duration of the canine retraction. In the PI group, the duration of the front retraction and the total treatment time was shorter compared to the DA group (P<0.05). No significant difference in molar mesial movement was found during canine retraction, but during front retraction, there was significantly less mesial molar movement in the PI group compared to the DA group (P<0.05). The use of palatal implant-based anchorage does not offer a shorter canine retraction period, but resulted in a significant shortening of the front-retraction phase and a total treatment time shortened by 5 months on average. The tooth stability in adolescent patients is adequate for tooth movements using both methods. PMID:23079140

Borsos, Gabriella; Vokó, Zoltan; Gredes, Tomasz; Kunert-Keil, Christiane; Vegh, Andras

2012-11-01

17

Single anterior tooth replacement by a cast lingual loop connector - a conservative approach.  

PubMed

One of the most challenging and complex treatment modality is replacement of single anterior tooth. This can be overcome by different treatment options such as implant-supported restorations as well as conventional porcelain-fused-to-metal and resin-bonded fixed partial dentures. Drifting of teeth into the edentulous area may reduce the available pontic space; whereas a diastema existing before an extraction may result in excessive mesiodistal dimension to the pontic space. Loop connector fixed partial denture (FPD) may be the simplest and best solution to maintain the diastema and provide optimum restoration of aesthetics. This article describes the procedure for the fabrication of a loop connector FPD to restore an excessively wide anterior edentulous space in a patient with existing spacing between the maxillary anterior teeth. PMID:25386535

Dandekeri, Shilpa Sudesh; Dandekeri, Savita

2014-09-01

18

Single Anterior Tooth Replacement by a Cast Lingual Loop Connector - A Conservative Approach  

PubMed Central

One of the most challenging and complex treatment modality is replacement of single anterior tooth. This can be overcome by different treatment options such as implant-supported restorations as well as conventional porcelain-fused-to-metal and resin-bonded fixed partial dentures. Drifting of teeth into the edentulous area may reduce the available pontic space; whereas a diastema existing before an extraction may result in excessive mesiodistal dimension to the pontic space. Loop connector fixed partial denture (FPD) may be the simplest and best solution to maintain the diastema and provide optimum restoration of aesthetics. This article describes the procedure for the fabrication of a loop connector FPD to restore an excessively wide anterior edentulous space in a patient with existing spacing between the maxillary anterior teeth. PMID:25386535

Dandekeri, Savita

2014-01-01

19

Alveolar ridge preservation of an extraction socket using autogenous tooth bone graft material for implant site development: prospective case series  

PubMed Central

This case series evaluated the clinical efficacy of autogenous tooth bone graft material (AutoBT) in alveolar ridge preservation of an extraction socket. Thirteen patients who received extraction socket graft using AutoBT followed by delayed implant placements from Nov. 2008 to Aug. 2010 were evaluated. A total of fifteen implants were placed. The primary and secondary stability of the placed implants were an average of 58 ISQ and 77.9 ISQ, respectively. The average amount of crestal bone loss around the implant was 0.05 mm during an average of 22.5 months (from 12 to 34 months) of functional loading. Newly formed tissues were evident from the 3-month specimen. Within the limitations of this case, autogenous tooth bone graft material can be a favorable bone substitute for extraction socket graft due to its good bone remodeling and osteoconductivity.

Yun, Pil-Young; Um, In-Woong; Lee, Hyo-Jung; Yi, Yang-Jin; Bae, Ji-Hyun; Lee, Junho

2014-01-01

20

Optimizing Maxillary Aesthetics of a Severe Compromised Tooth through Orthodontic Movement and Dental Implants  

PubMed Central

Treatment of severe compromised tooth in the maxillary anterior area still poses great challenge to the clinicians. Several treatment modalities have been proposed to restore the function and aesthetics in teeth with advanced periodontal disease. The present study aims to report a case of traumatic injury of a left-maxillary central incisor with ridge preservation, orthodontic movement, and implant therapy. A 45-year-old woman underwent the proposed treatment for her left central incisor: basic periodontal therapy, xenogenous bone graft, and guided bone regeneration (GBR). Six months after the graft procedure, orthodontic movement by means of alignment and leveling was made and a coronal displacement of the gingival margin and vertical bone apposition could be observed after 13 months of active movement. Afterwards, a dental implant was placed followed by a connective tissue graft and immediate provisionalization of the crown. In conclusion, orthodontic movement was effective to improve the gingival tissue and alveolar bone prior to implant placement favoring the aesthetic results. Six years postoperatively, the results revealed height and width alveolar bone gain indicating that the treatment proposed was able to restore all the functional and aesthetic parameters. PMID:24523969

de Avila, Erica Dorigatti; Cirelli, Joni Augusto; Cardoso, Mauricio de Almeida; Capelozza-Filho, Leopoldino; Borelli Barros, Luiz Antonio

2014-01-01

21

Mechanical design, analysis, and laboratory testing of a dental implant with axial flexibility similar to natural tooth with periodontal ligament.  

PubMed

At the interface between the jawbone and the roots of natural teeth, a thin, elastic, shock-absorbing tissue, called the periodontal ligament, forms a cushion which provides certain flexibility under mechanical loading. The dental restorations supported by implants, however, involve comparatively rigid connections to the jawbone. This causes overloading of the implant while bearing functional loading together with neighboring natural teeth, which leads to high stresses within the implant system and in the jawbone. A dental implant, with resilient components in the upper structure (abutment) in order to mimic the mechanical behavior of the periodontal ligament in the axial direction, was designed, analyzed in silico, and produced for mechanical testing. The aims of the design were avoiding high levels of stress, loosening of the abutment connection screw, and soft tissue irritations. The finite element analysis of the designed implant revealed that the elastic abutment yielded a similar axial mobility with the natural tooth while keeping stress in the implant at safe levels. The in vitro mechanical testing of the prototype resulted in similar axial mobility predicted by the analysis and as that of a typical natural tooth. The abutment screw did not loosen under repeated loading and there was no static or fatigue failure. PMID:25378380

Pekta?, Ömer; Tönük, Ergin

2014-11-01

22

Evaluation of Micromovements and Stresses around Single Wide-Diameter and Double Implants for Replacing Mandibular Molar: A Three-Dimensional FEA  

PubMed Central

Purpose. The purpose of this finite element study was to compare stresses, strains, and displacements of double versus single implant, in immediate loading for replacing mandibular molar. Materials and Methods. Two 3D FEM models were made to simulate implant designs. The first model used 6?mm wide-diameter implant to support a single molar crown. The second model used 3.75-3.75 double implant design. Each model was analyzed with a single force magnitude of 70?N in oblique axis in three locations. Results. This FEM study suggested that micromotion can be well controlled by both double implants and 6?mm single wide-diameter implant. The Von Mises stress for double implant had 31%–43% stress reduction compared to the 6?mm implant. Conclusion. Within the limitations of the paper, when the mesiodistal space for artificial tooth is more than 12.5?mm, under immediate loading, the double implant support should be considered. PMID:22461992

Desai, Shrikar R.; Karthikeyan, I.; Singh, Rika

2012-01-01

23

Single Ion Implantation and Deterministic Doping  

SciTech Connect

The presence of single atoms, e.g. dopant atoms, in sub-100 nm scale electronic devices can affect the device characteristics, such as the threshold voltage of transistors, or the sub-threshold currents. Fluctuations of the number of dopant atoms thus poses a complication for transistor scaling. In a complementary view, new opportunities emerge when novel functionality can be implemented in devices deterministically doped with single atoms. The grand price of the latter might be a large scale quantum computer, where quantum bits (qubits) are encoded e.g. in the spin states of electrons and nuclei of single dopant atoms in silicon, or in color centers in diamond. Both the possible detrimental effects of dopant fluctuations and single atom device ideas motivate the development of reliable single atom doping techniques which are the subject of this chapter. Single atom doping can be approached with top down and bottom up techniques. Top down refers to the placement of dopant atoms into a more or less structured matrix environment, like a transistor in silicon. Bottom up refers to approaches to introduce single dopant atoms during the growth of the host matrix e.g. by directed self-assembly and scanning probe assisted lithography. Bottom up approaches are discussed in Chapter XYZ. Since the late 1960's, ion implantation has been a widely used technique to introduce dopant atoms into silicon and other materials in order to modify their electronic properties. It works particularly well in silicon since the damage to the crystal lattice that is induced by ion implantation can be repaired by thermal annealing. In addition, the introduced dopant atoms can be incorporated with high efficiency into lattice position in the silicon host crystal which makes them electrically active. This is not the case for e.g. diamond, which makes ion implantation doping to engineer the electrical properties of diamond, especially for n-type doping much harder then for silicon. Ion implantation is usually a highly statistical process, where high fluences of energetic ions, ranging from {approx}10{sup 9} to >10{sup 16} cm{sup -2} are implanted. For single atom device development, control over the absolute number of ions is needed and ions have to be placed with high spatial resolution. In the following sections we will discuss a series of approaches to single ion implantation with regard to single ion impact sensing and control of single ion positioning.

Schenkel, Thomas

2010-06-11

24

Relationship between indication for tooth extraction and outcome of immediate implants: A retrospective study with 5 years of follow-up  

PubMed Central

Objectives: The aims of this retrospective study were to evaluate the survival rate of a series of immediate implants after 3 years of follow-up and to study the relationship between survival and indication for tooth extraction. Study Design: A retrospective study of patients treated with immediate implants between January 2003 and December 2008 was carried out. All patients receiving at least one post-extraction implant and a minimum follow-up of 5 years were included. Results: After 60 months, 30 immediate implants had been lost in 17 patients, yielding a total implant success rate of 93.8%. None of the implants placed failed after the extraction of included canines (100% success rate). In 20 failed implants the reason for extraction had been severe periodontal disease (91.8% SR), in 4 endodontic failure (88.6%SR), in 3 unrestorable caries (95.9% SR), in 1 untreatable fracture (95.2% SR) and in 2 improvement of prosthetic design (98.1% SR). No statistically significant influence was found between immediate implant failure and the reason for tooth extraction (p=0.11). Conclusions: The use of immediate implants is a successful alternative to replace missing teeth for severe periodontal disease, periapical pathology or by decay or untreatable fractures. Some reasons, such as periodontal disease itself is associated with a success rate significantly below the overall average. Similarly, the prosthetic design is associated with a better prognosis than all other reasons. Key words:Tooth extraction, immediate implants, success rate.

Tarazona-Álvarez, Pablo; Peñarrocha-Oltra, David; Peñarrocha-Diago, Maria

2014-01-01

25

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. PMID:22737309

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

2012-01-01

26

Single Color Centers Implanted in Diamond Nanostructures  

E-print Network

The development of materials processing techniques for optical diamond nanostructures containing a single color center is an important problem in quantum science and technology. In this work, we present the combination of ion implantation and top-down diamond nanofabrication in two scenarios: diamond nanopillars and diamond nanowires. The first device consists of a 'shallow' implant (~20nm) to generate Nitrogen-vacancy (NV) color centers near the top surface of the diamond crystal. Individual NV centers are then isolated mechanically by dry etching a regular array of nanopillars in the diamond surface. Photon anti-bunching measurements indicate that a high yield (>10%) of the devices contain a single NV center. The second device demonstrates 'deep' (~1\\mu m) implantation of individual NV centers into pre-fabricated diamond nanowire. The high single photon flux of the nanowire geometry, combined with the low background fluorescence of the ultrapure diamond, allows us to sustain strong photon anti-bunching even at high pump powers.

Birgit J. M. Hausmann; Thomas M. Babinec; Jennifer T. Choy; Jonathan S. Hodges; Sungkun Hong; Irfan Bulu; A. Yacoby; M. D. Lukin; Marko Lon?ar

2010-09-21

27

Comparative study of osteoblastic activity of same implants (Endopore) in the immediate extraction site utilizing single photon emission computerized tomography: peri-implant autogeneous bone grafting with GTR versus no peri-implant bone grafting--experimental study in pig model.  

PubMed

The study was designed to exploit the single photon emission computerized tomography (SPECT) to compare osteoblastic activity of two implant systems: an Endopore implant (Beaded implants) placed immediately into an extraction socket in conjunction with peri-implant autogenous grafting supplemented with a guided tissue regeneration (GTR) technique, and an Endopore implant placed immediately into the extraction socket without peri-implant grafting and GTR. Endopore implants of the same size (12 mm x 4.1 mm INT-Hex) were placed in fresh extraction sockets in the canine-tooth region of the pigs jaw. The implant on the right side had peri-implant bone grafting utilizing autogenous bone together with cytoplast resorbable GTR membrane, whilst the implant on the left side received no peri-implant bone grafting. Osteoblastic activity was evaluated 81 days (11 weeks and 4 days) post implantation using the SPECT imaging technique. The SPECT imaging revealed more osteoblastic activity on the side with peri-implant bone grafting as compared with the site without peri-implant bone grafting. The result suggests that peri-implant bone grafting with GTR around the immediate implant showed more osteoblastic activity and thus enhanced osseointegration when compared with the implant without bone grafting and GTR. Bone grafting and GTR should be encouraged as a standard procedure with dental implants. PMID:22224348

Ogunsalu, C; Ezeokoli, C; Archibald, A; Watkins, J; Stoian, C; Daisley, H; Legall, C; Lorde, S; Jackson, K; Jaggernauth, D; Nelson, A; Mungal, N

2011-06-01

28

In situ tooth replica custom implant: a 3-dimensional finite element stress and strain analysis.  

PubMed

This study is a phase of a biomechanical study, a part of a research program concerned with the new concept of in situ tooth replication. The purpose of the study was to evaluate tooth replica under each of two possible circumstances: (1) attachment via periodontal ligament and (2) osseointegration. Replicas were made of Cortoss, a bioactive glass, bone substitute. Three-dimensional finite element analysis was used to assess the stresses and strains resulting from each of 2 types of loads: off-vertical pressure and vertical point force acting on natural mandibular second premolar and corresponding replicas. Natural tooth tolerated 19 MPa pressure or 85 N vertical force, periodontally attached replica tolerated 15 MPa pressure or 80 N force, and osseointegrated replica tolerated 23 MPa pressure or 217 N force. PMID:21767213

Ghuneim, Wael Aly

2013-10-01

29

Mandibular exostosis in canine with single tooth recession - a rare case report.  

PubMed

Buccal exostoses occur along the buccal aspect of the maxilla or mandible, usually in the premolar and molar areas. It has been suggested that the bony outgrowth represents a reaction to increased or abnormal occlusal stress to the teeth in the involved areas. Gingival recessions may occur without any symptoms but may give rise to the patient concern about poor esthetics, dentine hypersensitivity, inability to perform oral hygiene procedures, and loss of the tooth. This article presents a rare case of exostosis in the mandibular right canine region and single tooth recession in the mandibular left central incisor region which was successfully managed by a combination of osseous resective surgery done to treat exostosis and lateral pedicle technique for root coverage. PMID:25214741

Jain, Rachna; Kapoor, Daljit; Sujay, J

2014-07-01

30

Mandibular Exostosis in Canine with Single Tooth Recession – A Rare Case Report  

PubMed Central

Buccal exostoses occur along the buccal aspect of the maxilla or mandible, usually in the premolar and molar areas. It has been suggested that the bony outgrowth represents a reaction to increased or abnormal occlusal stress to the teeth in the involved areas. Gingival recessions may occur without any symptoms but may give rise to the patient concern about poor esthetics, dentine hypersensitivity, inability to perform oral hygiene procedures, and loss of the tooth. This article presents a rare case of exostosis in the mandibular right canine region and single tooth recession in the mandibular left central incisor region which was successfully managed by a combination of osseous resective surgery done to treat exostosis and lateral pedicle technique for root coverage. PMID:25214741

Jain, Rachna; Kapoor, Daljit; Sujay, J

2014-01-01

31

Soft tissue manipulation for single implant restorations  

Microsoft Academic Search

Achievement of optimal aesthetics on implants in the anterior region can be difficult due to inherent differences to the natural dentition. An important consideration is the peri-implant soft tissues which can be modified to create a more natural emergence profile and contour. The methods with which this can be achieved vary as can methods for recording soft tissue changes and

M. Corson; A. Alani

2011-01-01

32

The management of traumatic tooth loss with dental implants: part 2. Severe trauma.  

PubMed

In part 2 of this series, we look at the clinician's role in replacing multiple missing teeth and the associated soft tissues and bone, following severe forms of trauma. These patients usually wish to have fixed prostheses to help restore their appearance and function. In order to fulfil the patient's request, the multidisciplinary team can be faced with significant challenges, often requiring extensive reconstructive surgery and complex implant oral rehabilitation. The aim of this paper is to highlight to the general dental practitioner some of the challenges faced in rehabilitating severe trauma patients with implant retained prosthesis. By understanding the challenges it is hoped that the general dental practitioner will be able to make an assessment of the clinical situation and seek appropriate specialist advice to ensure optimal results for their patients. In the longer term, the management of these patients requires a shared care approach between the general dental practitioner and relevant specialists. PMID:25525010

Seymour, D W; Patel, M; Carter, L; Chan, M

2014-12-01

33

Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices  

PubMed Central

We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7??W, which corresponded to a power density of 193.5??W?cm?2 and a volumetric power of 161??W?mL?1. We demonstrate that one single implanted enzymatic GBFC can power a light-emitting diode (LED), or a digital thermometer. In addition, no signs of rejection or inflammation were observed after 110?days implantation in the rat. PMID:23519113

Zebda, A.; Cosnier, S.; Alcaraz, J.-P.; Holzinger, M.; Le Goff, A.; Gondran, C.; Boucher, F.; Giroud, F.; Gorgy, K.; Lamraoui, H.; Cinquin, P.

2013-01-01

34

The management of an endodontically abscessed tooth: patient health state utility, decision-tree and economic analysis  

Microsoft Academic Search

BACKGROUND: A frequent encounter in clinical practice is the middle-aged adult patient complaining of a toothache caused by the spread of a carious infection into the tooth's endodontic complex. Decisions about the range of treatment options (conventional crown with a post and core technique (CC), a single tooth implant (STI), a conventional dental bridge (CDB), and a partial removable denture

Ben Balevi; Sasha Shepperd

2007-01-01

35

Single and Multiple Microphone Noise Reduction Strategies in Cochlear Implants  

PubMed Central

To restore hearing sensation, cochlear implants deliver electrical pulses to the auditory nerve by relying on sophisticated signal processing algorithms that convert acoustic inputs to electrical stimuli. Although individuals fitted with cochlear implants perform well in quiet, in the presence of background noise, the speech intelligibility of cochlear implant listeners is more susceptible to background noise than that of normal hearing listeners. Traditionally, to increase performance in noise, single-microphone noise reduction strategies have been used. More recently, a number of approaches have suggested that speech intelligibility in noise can be improved further by making use of two or more microphones, instead. Processing strategies based on multiple microphones can better exploit the spatial diversity of speech and noise because such strategies rely mostly on spatial information about the relative position of competing sound sources. In this article, we identify and elucidate the most significant theoretical aspects that underpin single- and multi-microphone noise reduction strategies for cochlear implants. More analytically, we focus on strategies of both types that have been shown to be promising for use in current-generation implant devices. We present data from past and more recent studies, and furthermore we outline the direction that future research in the area of noise reduction for cochlear implants could follow. PMID:22923425

Azimi, Behnam; Hu, Yi; Friedland, David R.

2012-01-01

36

Orthodontic treatment of an ankylosed maxillary central incisor through single-tooth osteotomy by using interdental space regained from microimplant anchorage.  

PubMed

This case report describes the treatment of a boy, aged 13.6 years, whose ankylosed maxillary left central incisor had been avulsed and replanted 2.5 years earlier. Ankylosis of the tooth and adjacent alveolar process led to the development of infraocclusion, migration of adjacent teeth, midline deviation, and a vertical alveolar bone defect. Initially, distal tooth movement in the maxillary arch was performed with microimplant anchorage to gain space for repositioning the ankylosed tooth. Then a single-tooth osteotomy was performed in 1 surgical stage to allow for inferior repositioning of the tooth and bone. The ankylosed tooth was successfully leveled in the maxillary arch with a harmonic gingival margin. The total treatment period was 18 months, and the results were acceptable at 14 months after debonding. PMID:22284297

Chae, Jong-Moon; Paeng, Jun-Young

2012-02-01

37

Biomaterial Selection for Tooth Regeneration  

PubMed Central

Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or synthetic polymers, three-dimensional scaffold fabrication, stem cell transplantation, and stem cell homing. A tooth is a complex biological organ. Tooth loss represents the most common organ failure. Tooth regeneration encompasses not only regrowth of an entire tooth as an organ, but also biological restoration of individual components of the tooth including enamel, dentin, cementum, or dental pulp. Regeneration of tooth root represents perhaps more near-term opportunities than the regeneration of the whole tooth. In the adult, a tooth owes its biological vitality, arguably more, to the root than the crown. Biomaterials are indispensible for the regeneration of tooth root, tooth crown, dental pulp, or an entire tooth. PMID:21699433

Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y.; Zhou, Hong

2011-01-01

38

Coexistence of two talon cusps and two dens invaginatus in a single tooth with associated radicular cyst-a case report and review of literature  

PubMed Central

Talon cusp (TC) and dens invaginatus (DI) are relatively rare developmental anomalies which affect the shape of teeth. TC is an additional cusp that projects predominately from the lingual surface of anterior teeth. DI is a deep surface invagination of the crown or root which is commonly detected on routine radiographic examination. Both of these anomalies are observed more frequently in permanent maxillary lateral incisor. Isolated cases of single TC and DI are extensively reported in dental literature. Occasionally two talon cusps (TCs) in the same tooth as well as double and triple invaginations in one tooth are reported separately. Coexistence of these two anomalies in a single tooth is considered extremely rare, but still there are few reported cases. However, coexistence of two TCs and double DI in a single tooth is not reported till date. We hereby report the first case of coexistence of two TCs and double DI in a single tooth of a 23 year old female and use of platelet-rich fibrin (PRF) in the management of associated radicular cyst. Also, literature on coexistence of these two anomalies in a single tooth is reviewed. Key words:Coexistence, dens invaginatus, radicular cyst, talon cusp. PMID:25593669

Singh, Mukund; Saluja, Harish; Ladda, Ruchi

2014-01-01

39

Process Performance of Optima XEx Single Wafer High Energy Implanter  

NASA Astrophysics Data System (ADS)

To meet the process requirements for well formation in future CMOS memory production, high energy implanters require more robust angle, dose, and energy control while maintaining high productivity. The Optima XEx high energy implanter meets these requirements by integrating a traditional LINAC beamline with a robust single wafer handling system. To achieve beam angle control, Optima XEx can control both the horizontal and vertical beam angles to within 0.1 degrees using advanced beam angle measurement and correction. Accurate energy calibration and energy trim functions accelerate process matching by eliminating energy calibration errors. The large volume process chamber and UDC (upstream dose control) using faraday cups outside of the process chamber precisely control implant dose regardless of any chamber pressure increase due to PR (photoresist) outgassing. An optimized RF LINAC accelerator improves reliability and enables singly charged phosphorus and boron energies up to 1200 keV and 1500 keV respectively with higher beam currents. A new single wafer endstation combined with increased beam performance leads to overall increased productivity. We report on the advanced performance of Optima XEx observed during tool installation and volume production at an advanced memory fab.

Kim, J. H.; Yoon, Jongyoon; Kondratenko, S.; David, J.; Rubin, L. M.; Jang, I. S.; Cha, J. C.; Joo, Y. H.; Lee, A. B.; Jin, S. W.

2011-01-01

40

A Conservative Treatment Approach to Replacing a Missing Anterior Tooth  

PubMed Central

An implant-supported crown or conventionally fixed partial denture is the most common treatment modality to replace a missing anterior tooth but a more conservative approach, with a fiber reinforced composite resin FPD, can be used to replace a missing anterior tooth in young patients or when the patient does not agree for an implant, or conventional FPD or RPD therapy. It is an esthetic, conservative single sitting chairside procedure which can be used as a definitive treatment alternative in certain clinical situations for esthetic and functional replacement of a missing anterior tooth. To achieve desirable results, putty matrix was used for proper positioning of the pontic during direct fabrication of FRCFPD. PMID:25254122

Singh, Kunwarjeet; Gupta, Nidhi; Unnikrishnan, Nandini; Kapoor, Vikram; Arora, Dhruv; Khinnavar, Poonam K.

2014-01-01

41

Chromium single photon emitters in diamond fabricated by ion implantation  

E-print Network

Controlled fabrication and identification of bright single photon emitters is at the heart of quantum optics and materials science. Here we demonstrate a controlled engineering of a chromium bright single photon source in bulk diamond by ion implantation. The Cr center has fully polarized emission with a ZPL centered at 749 nm, FWHM of 4 nm, an extremely short lifetime of ~1 ns, and a count rate of 500 kcounts/s. By combining the polarization measurements and the vibronic spectra, a model of the center has been proposed consisting of one interstitial chromium atom with a transition dipole along one of the directions.

Igor Aharonovich; Stefania Castelletto; Brett C. Johnson; Jeffrey C. McCallum; David A. Simpson; Andrew D. Greentree; Steven Prawer

2010-01-25

42

Finite Element Analysis of Bone around a Dental Implant Supporting a Crown with a Premature Contact  

Microsoft Academic Search

Objective: To investigate the influence of a premature contact caused by an implant-retained crown (IRC) on stress and strain distributions in bone surrounding the implant using the finite element method. Material and Method: A 3D finite element (FE) model of a section of a mandible with a single tooth dental implant, an IRC, and two adjacent teeth was created. Three

Ekachai Chaichanasiri; M Eng; Wichit Tharanon DDS; Jos Vander

2009-01-01

43

Single Tooth Replacement Using InCeram Resin Bonded Fixed Partial Denture: A Clinical Report  

PubMed Central

This clinical report describes a treatment option for replacement of a missing mandibular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD). The conventional approach for replacing mandibular incisors dictates the placement of either a conventional porcelain-fused-to-metal (PFM) bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure. PMID:24910683

Moslehifard, Elnaz; Farid, Farzaneh

2014-01-01

44

Tooth Disorders  

MedlinePLUS

... cavities (also known as tooth decay), infections, and injuries. The most familiar symptom of a tooth problem is a toothache. Others include worn-down or loose teeth. It's important that you see a dentist if ...

45

Tooth Numbering  

MedlinePLUS

... numbered as well. Illustrations created by Simple Steps designer Michael Becker Universal Numbering System Adults In this ... indicates that it is a deciduous (primary or "baby") tooth. So, a child's first tooth on the ...

46

Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year  

PubMed Central

SUMMARY Development of patient-based questionnaire about aesthetic and functional differences between overdentures implant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year. Objective The aim of this study is to compare functional efficiency and patients satisfaction between tooth-supported and implant-supported overdenture through a questionnaire that accurately reflects the real concerns of patients with dental prosthesis. Methods Forty-three patients were selected from the out patient clinic, Department of Dentistry “Fra G.B. Orsenigo Ospedale San Pietro F.B.F.”, Rome, Italy. Their age were ranging from 61 to 83 years. Eighteen patients were rehabilitated with overdentures supported by natural teeth and twenty-five with overdentures implant-supported. Discussion and Result The questionnaire proposed one year after the insertion of the prosthetis has showed that there isn’t difference statistically significant in terms of function, phonetics and aesthetics between overdenture implant-supported and tooth-supported. Conclusions The results of the questionnaire showed that the patients generally had a high level of satisfaction concern to the masticatory function, esthetics and phonetics. In addition, on average, they haven’t difficulty in removal and insertion of the denture and in oral hygiene. They haven’t in both groups problems related to fractures. PMID:23741602

GARGARI, M.; PRETE, V.; PUJIA, M.; CERUSO, F. M.

2013-01-01

47

Tooth Abrasion and Tooth Erosion  

MedlinePLUS

... protects the innermost part of the tooth, the pulp, which contains nerves and blood vessels. Abrasion and ... can damage the center of the tooth, the pulp. The more damage is done, the more work ...

48

Optimized single pulse stimulation strategy for retinal implants  

NASA Astrophysics Data System (ADS)

Retinal implants offer prospects of vision restoration for some blind patients by eliciting visual percepts of spots of light called ‘phosphenes’. Recently, a mathematical model has been developed that predicts patients' perception of phosphene brightness for current-driven electrical stimulation of the retina. This model is explored for different stimulation parameters on a single electrode, including safety and hardware limitations, to produce phosphenes of specified brightness. We describe a procedure to derive stimulation parameters to account for such constraints, and describe methods to construct optimal stimuli in terms of producing maximal perceived brightness and efficient generation of phosphenes of a given brightness by employing minimal energy. In both cases, it is found that the resulting optimized stimulation waveforms consist of a long stimulation period, and interphase delays between initial and charge-balancing phases.

Savage, C. O.; Grayden, D. B.; Meffin, H.; Burkitt, A. N.

2013-02-01

49

Optimized single pulse stimulation strategy for retinal implants.  

PubMed

Retinal implants offer prospects of vision restoration for some blind patients by eliciting visual percepts of spots of light called 'phosphenes'. Recently, a mathematical model has been developed that predicts patients' perception of phosphene brightness for current-driven electrical stimulation of the retina. This model is explored for different stimulation parameters on a single electrode, including safety and hardware limitations, to produce phosphenes of specified brightness. We describe a procedure to derive stimulation parameters to account for such constraints, and describe methods to construct optimal stimuli in terms of producing maximal perceived brightness and efficient generation of phosphenes of a given brightness by employing minimal energy. In both cases, it is found that the resulting optimized stimulation waveforms consist of a long stimulation period, and interphase delays between initial and charge-balancing phases. PMID:23220887

Savage, C O; Grayden, D B; Meffin, H; Burkitt, A N

2013-02-01

50

Implants  

MedlinePLUS

... vs. Alternatives Implants are devices that replace the roots of missing teeth. They are used to support ... confidence. There are several types of implants, including: Root form Subperiosteal Mini Root-form implants are the ...

51

Immediate restoration of single implants placed immediately after implant removal. A case report.  

PubMed

The purpose of this case report is to describe the treatment of implants placed in fresh extraction sockets and immediately restored in cases of failure. A healthy 58-year-old nonsmoking man was referred for an implant that had lost osseointegration because of infection. The prosthesis showed slight mobility. It was therefore decided to remove the implant and replace it with a new one immediately. Since the patient refused to wear a provisional removable prosthesis, the possibility of applying an immediate loading protocol was discussed. The failed implant was removed carefully and the residual extraction socket was thoroughly debrided. Subsequently, the new implant was placed with a sterile surgical technique, as described by the manufacturer. The inserted implant had a titanium plasma-sprayed surface. Immediately following implant placement and with the patient still under local anesthesia, the initial restorative treatment began. The patient was placed on a strict follow-up regimen until soft tissue healing was complete. Subsequent follow-up examinations were performed after 12 months. At each recall, the patient underwent a thorough clinical and radiographic evaluation. The healing period proceeded smoothly. At the end of the follow-up period, the implant was asymptomatic, immobile, and osseointegrated. No peri-implant bony defects were observed on probing. The results of the present case report seem to suggest that implants placed in fresh extraction sockets and restored immediately might provide a valid treatment option for the treatment of failed implants. PMID:20967310

Covani, Ugo; Marconcini, Simone; Santini, Stefano; Cornelini, Roberto; Barone, Antonio

2010-12-01

52

Study of ytterbium implanted calcia stabilized zirconia thin films and yttria stabilized zirconia single crystals  

Microsoft Academic Search

Calcia stabilized zirconia thin films and yttria stabilized zirconia single crystals were Yb implanted at 150 and 210 keV, and at various doses up to 1.3 × 10 ions\\/cm in order to modify locally the oxygen transport properties. Rutherford back-scattering and nuclear microanalysis on the implanted thin films give information about the implantation profiles and sputtering yields. The results show

C. Cohen; J. Siejka; M. Berti; A. V. Drigo; M. Croset; M. M. Tosic

1982-01-01

53

Tooth Discoloration  

MedlinePLUS

... layer of the tooth (the enamel) is stained. Coffee, wine, cola or other drinks or foods can ... An example would be the stains caused by coffee. Many stains are permanent, however. Teeth sometimes can ...

54

Tooth Extraction  

MedlinePLUS

... loosens the tooth with an instrument called an elevator. Then the dentist uses an instrument called a ... difficult extractions. Smokers and women who take birth control pills are more likely to have a dry ...

55

In Vitro Assessment of Single-Retainer Tooth-Colored Adhesively Fixed Partial Dentures for Posterior Teeth  

PubMed Central

The purpose of this paper was to investigate, by means of marginal adaptation and fracture strength, three different types of single retainer posterior fixed partial dentures (FPDs) for the replacement of a missing premolar. Two-unit cantilever FPDs were fabricated from composite resin, feldspathic porcelain, and fiber-reinforced composite resin. After luting procedures and margin polishing, all specimens were subjected to a Scanning Electron Microscopic marginal evaluation both prior to and after thermomechanical loading with a custom made chewing simulator comprising both thermal and mechanical loads. The results indicated that the highest score of marginal adaptation, that is, the closest score to 100% of continuous margins, at the tooth-composite resin interface was attained by the feldspathic porcelain group (88.1% median), followed by the fiber-reinforced composite resin group (78.9% median). The worse results were observed in the composite resin group (58.05% median). Fracture strength was higher in feldspathic porcelain (196N median) when compared to resin composite (114.9 N median). All the fixed prostheses made of fiber-reinforced composite resin detached from the abutment teeth before fracturing, suggesting that the adhesive surface's retainer should be increased. PMID:20652071

Bortolotto, Tissiana; Monaco, Carlo; Onisor, Ioana; Krejci, Ivo

2010-01-01

56

Dynamic fatigue properties of the dental implant–abutment interface: Joint opening in wide-diameter versus standard-diameter hex-type implants  

Microsoft Academic Search

Statement of problem. The clinical long-term success of single-tooth implant restorations depends, in part, on a stable connection between the prosthetic restoration and the implant body. Purpose. The purpose of this experiment was to investigate the fatigue life of UCLA-style abutment screws in wide-diameter versus conventionally sized dental implant restorations. Material and methods. Five 3.75 × 15-mm and five 6.0

Scott A. Hoyer; Clark M. Stanford; Supanee Buranadham; Todd Fridrich; Jacob Wagner; David Gratton

2001-01-01

57

The local structure and ferromagnetism in Fe-implanted SrTiO3 single crystals  

NASA Astrophysics Data System (ADS)

We report a connection between the local structure of low-level Fe impurities and vacancies as the cause of ferromagnetic behavior observed in strontium titanate single crystals (STO), which were implanted with Fe and Si ions at different doses then annealed in oxygen. The effects of Fe doping and post-implantation annealing of STO were studied by X-ray Absorption Near Edge Structure (XANES) spectroscopy and Superconducting Quantum Interference Device magnetometry. XANES spectra for Fe and Ti K- and L-edge reveal the changes in the local environment of Fe and Ti following the implantation and annealing steps. The annealing in oxygen atmosphere partially healed implantation damages and changed the oxidation state of the implanted iron from metallic Fe0 to Fe2+/Fe3+ oxide. The STO single crystals were weak ferromagnets prior to implantation. The maximum saturation moment was obtained after our highest implantation dose of 2 × 1016 Fe atom/cm2, which could be correlated with the metallic Fe0 phases in addition to the presence of O/Ti vacancies. After recrystallization annealing, the ferromagnetic response disappears. Iron oxide phases with Fe2+ and Fe3+ corresponding to this regime were identified and confirmed by calculations using Real Space Multiple Scattering program (FEFF9).

Lobacheva, O.; Chavarha, M.; Yiu, Y. M.; Sham, T. K.; Goncharova, L. V.

2014-07-01

58

Single photon emission from SiV centres in diamond produced by ion implantation  

NASA Astrophysics Data System (ADS)

We report the observation of single photon emission from single SiV (silicon-vacancy) centres in diamond produced by ion implantation. The high photostability and the narrow emission bandwidth of about 5 nm at room temperature make SiV centres interesting as a single photon source in practical quantum cryptography. We discuss problems that arise from the nonradiaditve transitions which lower the brightness of the source.

Wang, Chunlang; Kurtsiefer, Christian; Weinfurter, Harald; Burchard, Bernd

2006-01-01

59

Forced orthodontic eruption of fractured teeth before implant placement: case report.  

PubMed

The treatment of esthetic areas with single-tooth implants represents a new challenge for the clinician. Placement of a single-unit implant is indicated for fractured or periodontally compromised teeth. In 1993, a modification of the forced eruption technique, called "orthodontic extrusive remodelling," was proposed as a way to augment both soft- and hard-tissue profiles at potential implant sites. This case report describes augmentation of the coronal soft and hard tissues around a fractured tooth, which was achieved by forced orthodontic extrusion before implant placement. This technique may be used to improve primary anchorage of a dental implant, fill the alveolar socket with bone, preserve interdental bone height and increase the amount of attached gingiva. PMID:15871774

Chambrone, Leandro; Chambrone, Luiz A

2005-04-01

60

Effect of H + ion implantation on structural, morphological, optical and dielectric properties of L-arginine monohydrochloride monohydrate single crystals  

NASA Astrophysics Data System (ADS)

L-arginine monohydrochloride monohydrate (LAHCl) single crystals have been implanted with 100 keV H + ions at different ion fluence ranging from 10 12 to 10 15 ions/cm 2. Implanted LAHCl single crystals have been investigated for property changes. Crystal surface and crystalline perfection of the pristine and implanted crystals were analyzed by atomic force microscope and high-resolution X-ray diffraction studies, respectively. Optical absorption bands induced by colour centers, refractive index and birefringence, mechanical stability and dielectric constant of implanted crystals were studied at different ion fluence and compared with that of pristine LAHCl single crystal.

Sangeetha, K.; Babu, R. Ramesh; Kumar, P.; Bhagvannarayana, G.; Ramamurthi, K.

2011-06-01

61

Formation of oriented nitrides by N+ ion implantation in iron single crystals  

NASA Astrophysics Data System (ADS)

Iron single crystals were implanted with nitrogen at room temperature, with a fluence of 5×1017 cm-2 and 50 keV energy, to produce iron nitride phases and characterize the influence of the crystal orientation. The stability and evolution of the nitride phases and diffusion of implanted nitrogen were studied as a function of successive annealing treatments at 250 °C in vacuum. The composition, structure and magnetic properties were characterized using RBS/channeling, X-Ray Diffraction, Magnetic Force Microscopy, Magneto-optical Kerr Effect and Conversion Electron Mössbauer Spectroscopy. In the as-implanted state the formation of Fe2N phase was clearly identified in all single crystals. This phase is not stable at 250 °C and annealing at this temperature promotes the formation of ?-Fe3N, or ?'-Fe4N, depending on the orientation of the substrate. class="graphical"

Costa, A. R. G.; da Silva, R. C.; Ferreira, L. P.; Carvalho, M. D.; Silva, C.; Franco, N.; Godinho, M.; Cruz, M. M.

2014-01-01

62

An overview of immediate root analogue zirconia implants.  

PubMed

Owing to its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia has the potential to become a substitute for titanium as dental implant material and to be successfully used as root-analogue implants by reproducing the contours of the extracted tooth. This article presents an overview of the technique of using root analogue zirconia dental implants as an immediate implantation material. These implants are replicas of the extracted tooth and therefore truly anatomically correct and socket friendly. PMID:21905912

Regish, K M; Sharma, Deeksha; Prithviraj, D R

2013-04-01

63

Single-color centers implanted in diamond nanostructures  

E-print Network

The development of material-processing techniques that can be used to generate optical diamond nanostructures containing a single-color center is an important problem in quantum science and technology. In this work, we ...

Hausmann, Birgit J. M.

64

Effect of N5+ ion implantation in CVT grown ZnSe single crystals  

NASA Astrophysics Data System (ADS)

The ZnSe single crystals were grown by chemical vapor transport (CVT) technique using iodine as a transporting agent. As grown ZnSe single crystals have been implanted by N5+ ion at 45 keV energy in room temperature with various fluences of 1×1015, 5×1015, 1×1016 and 5×1016 ions/cm2. The lattice constants of the as grown and implanted ZnSe single crystals are 5.57 and 5.45 Å respectively. The photoluminescence studies reveal that N5+ implanted ZnSe has the band edge emission at 468 nm (2.64 eV) and broad luminescence peak due to defect level green emission at 551 nm (2.25 eV) and yellow emission 592 nm (2.09 eV). The as grown ZnSe crystal has the absorption cut off at 483 nm whereas the cut off increases from 489 to 524 nm with an increase in ion fluences. The frequency of vibration for as grown ZnSe crystal is 504 cm-1 and for implanted ZnSe samples, the frequencies are 657-677 cm-1 (N?Zn bending mode) and 2337-2353 cm-1 (N?Se stretching mode) which are due to bond formation of N.

Kannappan, P.; Krishna, J. B. M.; Taki, G. S.; Dhanasekaran, R.

2013-01-01

65

Cross-sectional transmission electron microscopy method and studies of implant damage in single crystal diamond  

SciTech Connect

Few transmission electron microscopy (TEM) studies of single crystal diamond have been reported, most likely due to the time and difficulty involved in sample preparation. A method is described for creating a TEM cross section of single crystal diamond using a focused ion beam and in situ lift-out. The method results in samples approximately 10 {mu}m long by 3 {mu}m deep with an average thickness of 100-300 nm. The total time to prepare a cross-sectional TEM sample of diamond is less than 5 h. The method also allows for additional thinning to facilitate high resolution TEM imaging, and can be applied to oddly shaped diamond samples. This sample preparation technique has been applied to the study of ion implantation damage in single crystal diamond and its evolution upon annealing. High-pressure-high-temperature diamonds were implanted with Si{sup +} at an energy of 1 MeV and a temperature of 30 deg. C. One sample, with a (110) surface, was implanted with a dose of 1x10{sup 14} Si cm{sup -2} and annealed at 950 deg. C for 10 and 40 min. No significant defect formation or evolution was discernible by cross-sectional transmission electron microscopy. Another sample, with a (100) orientation, was implanted with 1 MeV at 1x10{sup 15} Si cm{sup -2} and annealed at 1050 deg. C for 10 min. Prior to annealing, a heavily damaged but still crystalline region was observed. Upon annealing, the sample showed no signs of conversion either to an amorphous form of carbon or to graphite. This is unexpected as the energy and dose are above the previously reported graphitization threshold for diamond. Higher annealing temperatures and possibly a high vacuum will be required for future study of defect formation, evolution, and phase transformations in ion-implanted single crystal diamond.

Hickey, D.P.; Kuryliw, E.; Siebein, K.; Jones, K.S.; Chodelka, R.; Elliman, R. [Materials Science and Engineering Department, University of Florida, Gainesville, Florida 32611-6400 (United States); Gemesis Corporation, 7040 Professional Parkway East, Sarasota, Florida 34240 (United States); Electronic Materials Engineering Department, Research School of Physical Sciences and Engineering, Australian National University, Canberra Act 0200 (Australia)

2006-07-15

66

Tooth Agenesis: from Molecular Genetics to Molecular Dentistry  

Microsoft Academic Search

Tooth agenesis may originate from either genetic or environmental factors. Genetically determined hypodontic disorders appear as isolated features or as part of a syndrome. Msx1, Pax9, and Axin2 are involved in non-syndromic hypodontia, while genes such as Shh, Pitx2, Irf6, and p63 are considered to participate in syndromic genetic disorders, which include tooth agenesis. In dentistry, artificial tooth implants represent

E. Matalova; J. Fleischmannova; P. T. Sharpe; A. S. Tucker

2008-01-01

67

Chick tooth induction revisited.  

PubMed

Teeth have been missing from Aves for almost 100 million years. However, it is believed that the avian oral epithelium retains the molecular signaling required to induce odontogenesis, and this has been widely examined using heterospecific recombinations with mouse dental mesenchyme. It has also been argued that teeth can form from the avian oral epithelium owing to contamination of the mouse mesenchyme with mouse dental epithelial cells. To investigate the possibility of tooth formation from chick oral epithelium and the characteristics of possible chick enamel, we applied LacZ transgenic mice during heterospecific recombination and examined the further tooth formation. Transmission electron microscopy was used to identify the two tissues during development after heterospecific recombination. No mixing was detected between chick oral epithelium and mouse dental mesenchyme after 2 days, and secretory ameloblasts with Tomes' processes were observed after 1 week. Teeth were formed after 3 weeks with a single cusp pattern, possibly determined by epithelial factors, which is similar to that of the avian tooth in the late Jurassic period. These recombinant teeth were smaller than mouse molars, whereas perfect structures of both ameloblasts and enamel showed histological characteristics similar to those of mice. Together these observations consistent with previous report that odontogenesis is initially directed by species-specific mesenchymal signals interplaying with common epithelial signals. PMID:19226602

Cai, Jinglei; Cho, Sung-Won; Ishiyama, Mikio; Mikami, Masato; Hosoya, Akihiro; Kozawa, Yukishige; Ohshima, Hayato; Jung, Han-Sung

2009-07-15

68

The experience of artificial urinary sphincter implantation by a single surgeon in 15 years.  

PubMed

Artificial urinary sphincter (AUS) is the gold standard treatment for urinary incontinence owing to sphincter incompetence. We reviewed our experience in AUS implantation. From 1995 to 2009, 19 patients underwent 25 AUS implantations performed by a single surgeon. The cause of incontinence was sphincter incompetence, which was secondary to prostate surgery, neurogenic bladder, radiation, and post-traumatic urethral lesion. Twenty-three prostheses were placed in the bulbar urethra for male patients: 11 AUS cuffs were placed through the perineal approach and 12 through the penoscrotal approach. Two procedures were applied over the bladder neck for the female patients. Through a retrospective review of charts, continence and complications were analyzed. The mean follow-up time was 50.0 ± 42.9 months (range: 2-146 months). There were 16 successful surgeries (64%), and these patients were free from the need for a pad. In eight surgeries (32%), the devices were removed due to infection, while one implantation (4%) was unsuccessful due to perforation into the bulbar urethra. There was a statistically significant difference (p = 0.024) in failure rates between patients who received radiotherapy (100%) and other patients (22.7%). There was no statistically significant difference in dry and revision rates (p > 0.05) between the perineal and penoscrotal approach. Accordingly, over half of the patients with total incontinence benefitted from AUS implantation. In consideration of the high failure rate for patients receiving radiotherapy, caution should be exercised in the use of implantation. Secondary implantation has a satisfactory success rate in selected patients. The same success rate was noted for both perineal and penoscrotal approaches. PMID:23465419

Shen, Yuan-Chi; Chiang, Po-Hui

2013-03-01

69

Magnetic and structural characterization of Mn-implanted, single-crystal S. J. Pearton,a)  

E-print Network

Magnetic and structural characterization of Mn-implanted, single-crystal ZnGeSiN2 S. J. Pearton ZnGeN2 and ZnSiN2 have lattice parameters close to those of GaN and SiC, respectively.27 and microwave power electronic devices fabricated in the GaN and SiC. The band gap of ZnGexSi1 xN2 varies

Hebard, Arthur F.

70

Simulation of phosphorus implantation into silicon with a single-parameter electronic stopping power model  

Microsoft Academic Search

We simulate dopant profiles for phosphorus implantation into silicon using a\\u000anew model for electronic stopping power. In this model, the electronic stopping\\u000apower is factorized into a globally averaged effective charge Z1*, and a local\\u000acharge density dependent electronic stopping power for a proton. There is only\\u000aa single adjustable parameter in the model, namely the one electron radius

DAVID CAI; CHARLES M. SNELL; KEITH M. BEARDMORE; NIELS GRØNBECH-JENSEN

1999-01-01

71

Familial tooth bone graft for ridge and sinus augmentation: a report of two cases  

PubMed Central

Recently, clinical application of autogenous tooth bone-graft materials has been reported. Autogenous tooth bone graft has been used in implant surgery. Familial tooth bone graft is a more advanced procedure than autogenous teeth bone graft in that extracted teeth can be used for bone graft materials of implant and teeth donation between siblings is possible. We used autogenous tooth and familial tooth bone-graft materials for ridge augmentation and sinus bone graft and obtained satisfactory results. The cases are presented herein. PMID:24627842

Kim, Young-Kyun; Lim, Sung-Chul

2014-01-01

72

A statistical framework for the registration of 3D knee implant components to single-plane X-ray images  

Microsoft Academic Search

Registration of 3D knee implant components to single-plane X-ray image sequences provides insight into implanted knee kinematics. In this paper a maximum likelihood approach is proposed to align the pose-related occluding contour of an object with edge segments extracted from a single-plane X-ray image. This leads to an expectation maximization algorithm which simultaneously determines the objectpsilas pose, estimates point correspondences

J. Hermans; J. Bellemans; F. Maes; D. Vandermeulen; P. Suetens

2008-01-01

73

Open questions in electronic sputtering of solids by slow highly charged ions with respect to applications in single ion implantation  

SciTech Connect

In this article we discuss open questions in electronic sputtering of solids by slow, highly charged ions in the context of their application in a single ion implantation scheme. High yields of secondary electrons emitted when highly charged dopant ions impinge on silicon wafers allow for formation of non-Poissonian implant structures such as single atom arrays. Control of high spatial resolution and implant alignment require the use of nanometer scale apertures. We discuss electronic sputtering issues on mask lifetimes, and damage to silicon wafers.

Schenkel, T.; Rangelow, I.W.; Keller, R.; Park, S.J.; Nilsson, J.; Persaud, A.; Radmilivitc, V.R.; Liddle, J.A.; Grabiec, P.; Bokor, J.; Schneider, D.H.

2003-07-16

74

Room-temperature ferromagnetism in Cu-implanted 6H-SiC single crystal  

NASA Astrophysics Data System (ADS)

200 keV Cu+ ions were implanted into 6H-SiC single crystal at room temperature with fluence of 8 × 1015 cm-2. No ferromagnetism (FM)-related secondary phase was found by the results of high-resolution x-ray diffraction and x-ray photoelectron spectroscopy. Positron annihilation lifetime spectroscopy results indicated that the main defect type was silicon vacancy and the concentration of it increased after Cu implantation. The room-temperature ferromagnetism was detected by superconducting quantum interference device. First-principles calculations revealed that the magnetic moments mainly come from the 2p orbitals of C atoms and 3d orbitals of Cu dopant. The origin of the FM has been discussed in detail.

Zheng, H. W.; Yan, Y. L.; Lv, Z. C.; Yang, S. W.; Li, X. G.; Liu, J. D.; Ye, B. J.; Peng, C. X.; Diao, C. L.; Zhang, W. F.

2013-04-01

75

Low energy oxygen implantation induced improved crystallinity and optical properties of surface modified ZnO single crystals  

NASA Astrophysics Data System (ADS)

We report on the low energy oxygen implantation induced improvement in crystallinity and optical properties of surface modified ZnO single crystals. Undoped ZnO (0 0 0 1) single crystal wafers are implanted with 100 keV oxygen ions at a dose of 5 × 10 13 and 5 × 10 14 cm -2 and subsequently annealed at 500 and 600 °C in oxygen ambient. The as-implanted and annealed ZnO wafers are studied by Rutherford back scattering spectrometry (RBS), channeling, Raman, photoluminescence (PL), and Fourier transform infrared spectroscopy (FTIR). Channeling studies show a relatively high ?min (>20%) in the virgin ZnO wafer. After implantation and two-step annealing, RBS studies show improved crystallinity. Raman line width analysis for the E2high mode indicates reduction in strain in the annealed samples as compared to the virgin ZnO wafer. As-implanted samples show drastic quenching of the near band-edge (NBE) PL band due to defects created by the implantation. However, after two-step annealing, the low-dose implanted sample show a five-fold increase in intensity ratio of NBE band (376 nm) to defect related broad band (˜530 nm) at room temperature. Implantation induced changes in the composition and improved crystallinity in the near surface region is accounted for the major improvement in the PL emission.

Giri, P. K.; Kumari, Satchi; Goswami, D. K.

2009-10-01

76

Comparison of Maxillary Molar Distalization with an Implant-Supported Distal Jet and a Traditional Tooth-Supported Distal Jet Appliance  

PubMed Central

Aim. To investigate and compare the efficiency of two appliances for molar distalization: the bone-anchored distal screw (DS) and the traditional tooth-supported distal jet (DJ) for molar distalization and anchorage loss. Methods. Tests (18 subjects) were treated with a DS and controls (18 subjects) were treated with a DJ. Lateral cephalograms were obtained before and at the end of molar distalization and were analysed. Shapiro Wilk test, unpaired t-test, and Wilcoxon rank-sum test were applied according to values distribution. The ? level was fixed at 0.05. Results. Maxillary first molars were successfully distalized into a Class I relationship in all patients. The mean molar distalization and treatment time were similar in both groups. The DS group exhibited a spontaneous distalization (2.1 ± 0.9?mm) of the first premolar with control of anchorage loss, distal tipping, extrusion, and skeletal changes. Conclusions. The DS is an adequate compliance-free distalizing appliance that can be used safely for the correction of Class II malocclusions. In comparison to the traditional DJ, the DS enables not only a good rate of molar distalization, but also a spontaneous distalization of the first premolars. PMID:25018770

Cozzani, Mauro; Pasini, Marco; Zallio, Francesco; Ritucci, Robert; Mutinelli, Sabrina; Mazzotta, Laura; Giuca, Maria Rita; Piras, Vincenzo

2014-01-01

77

Implant identification system.  

PubMed

Osseointegrated oral implantology has become a widespread option of dental care. A universal system of implant identification is required to enable dentists, patients and participating third parties to accurately identify a particular implant and historically record and follow its bio-clinical status. A simple system, based on the existing FDI two-digit tooth identification system is presented. PMID:10858743

Colgan, P J

1999-04-01

78

Seal Out Tooth Decay  

MedlinePLUS

... dental sealants for my children? What are dental sealants? Sealants are thin, plastic coatings painted on the ... over the tooth. Back to Top How are sealants put on? 1. The tooth is cleaned. 2. ...

79

Replacing a Missing Tooth  

MedlinePLUS

... born with a missing tooth, most often the lateral incisor (immediately next to the front central incisor). This ... and maintained for later replacement of the missing lateral incisor. During orthodontic treatment, an artificial tooth may be ...

80

Printing of Titanium implant prototype  

Microsoft Academic Search

Dental implant plays an important role as a conduit of force and stress to flow from the tooth to the related bone. In the load sharing between an implant and its related bone, the amount of stress carried by each of them directly related to their stiffness or modulus. Hence, it is a crucial issue for the implant to have

Florencia Edith Wiria; John Yong Ming Shyan; Poon Nian Lim; Francis Goh Chung Wen; Jin Fei Yeo; Tong Cao

2010-01-01

81

Single- and Multi-Channel Modulation Detection in Cochlear Implant Users  

PubMed Central

Single-channel modulation detection thresholds (MDTs) have been shown to predict cochlear implant (CI) users’ speech performance. However, little is known about multi-channel modulation sensitivity. Two factors likely contribute to multichannel modulation sensitivity: multichannel loudness summation and the across-site variance in single-channel MDTs. In this study, single- and multi-channel MDTs were measured in 9 CI users at relatively low and high presentation levels and modulation frequencies. Single-channel MDTs were measured at widely spaced electrode locations, and these same channels were used for the multichannel stimuli. Multichannel MDTs were measured twice, with and without adjustment for multichannel loudness summation (i.e., at the same loudness as for the single-channel MDTs or louder). Results showed that the effect of presentation level and modulation frequency were similar for single- and multi-channel MDTs. Multichannel MDTs were significantly poorer than single-channel MDTs when the current levels of the multichannel stimuli were reduced to match the loudness of the single-channel stimuli. This suggests that, at equal loudness, single-channel measures may over-estimate CI users’ multichannel modulation sensitivity. At equal loudness, there was no significant correlation between the amount of multichannel loudness summation and the deficit in multichannel MDTs, relative to the average single-channel MDT. With no loudness compensation, multichannel MDTs were significantly better than the best single-channel MDT. The across-site variance in single-channel MDTs varied substantially across subjects. However, the across-site variance was not correlated with the multichannel advantage over the best single channel. This suggests that CI listeners combined envelope information across channels instead of attending to the best channel. PMID:24918605

Galvin, John J.; Oba, Sandy; Fu, Qian-Jie; Ba?kent, Deniz

2014-01-01

82

[Single and multi-teeth fixed prostheses--functions and types].  

PubMed

A single fixed prosthesis replaces parts of a tooth. However, a single fixed prosthesis may also be implant supported and in such a case it replaces in combination with the oral implant an entire tooth. A multi-teeth fixed prosthesis replaces 1 or more teeth using pontics and can be fixed on teeth, oral implants, or both. Materials applied are metal, metal fused with porcelain, and ceramic. After indicating a fixed prosthesis, the intended function is determining the appropriate type. Intended functions of single fixed prosthesis are: improvement of aesthetics, limitation of tooth fracture, acting as an abutment tooth for a removable metal frame partial denture, and splinting of mobile teeth. In addition, single fixed prostheses may be characterized by the number of replaced tooth surfaces and by the peripheral extension of the tooth preparation. The intended functions of a multi-teeth fixed prosthesis are improvement of aesthetics, chewing function, and occlusal as well as mandibular stability. Specific types of fixed prosthesis are used as temporary restorations and in case of evaluating preliminary treatments preceding a final treatment. PMID:23373305

Witter, D J; Hoefnagel, R A; Gerritsen, A E; Creugers, N H J

2012-12-01

83

Fast and Successful Management of Intraocular Inflammation with a Single Intravitreal Dexamethasone Implant.  

PubMed

Purpose: To investigate the efficacy and safety of a single dexamethasone intravitreal implant (Ozurdex®, 700 µg). Methods: In this prospective noncomparative case series, 84 patients (54 females) received a dexamethasone intravitreal implant. At weeks 4, 12 and 24 after the injection, vitreous haze, macular thickness and best corrected visual acuity (BCVA) were assessed and adverse events reported. Results: Clearance of vitreous haze could be achieved after 4 weeks in 61% of all eyes (p < 0.001) and remained significant until week 24 (p < 0.001). This was paralleled by a reduction of central retinal thickness after 4 (p < 0.001), 12 (p < 0.001) and 24 weeks (p < 0.006). Significant and fast improvement of BCVA was already achieved after 4 weeks (p < 0.001) but vanished by week 24. Intraocular pressure reached ?35 mm Hg in 3 eyes and was significantly more frequent in intermediate uveitis compared to posterior uveitis (p < 0.016). Conclusions: The dexamethasone implant is effective in controlling intraocular posterior segment inflammation and reduces central retinal thickness fast and effectively. © 2014 S. Karger AG, Basel. PMID:25428335

Pleyer, Uwe; Klamann, Matthias; Laurent, Thierry-Jens; Mänz, Martin; Hazirolan, Dicle; Winterhalter, Sibylle; Thurau, Stephan R

2014-11-21

84

Mechanical behavior of single-layer ceramized zirconia abutments for dental implant prosthetic rehabilitation  

PubMed Central

Objectives: This study was undertaken to characterize the mechanical response of bare (as-received) and single-layer ceramized zirconia abutments with both internal and external connections that have been developed to enhanced aesthetic restorations. Material and Methods: Sixteen zirconia implant abutments (ZiReal Post®, Biomet 3i, USA) with internal and external connections have been analyzed. Half of the specimens were coated with a 0.5mm-thick layer of a low-fusing fluroapatite ceramic. Mechanical tests were carried out under static (constant cross-head speed of 1mm/min until fracture) and dynamic (between 100 and 400N at a frequency of 1Hz) loading conditions. The failure location was identified by electron microscopy. The removal torque of the retaining screws after testing was also evaluated. Results: The average fracture strength was above 300N for all the abutments, regardless of connection geometry and coating. In most of the cases (94%), failure occurred by abutment fracture. No significant differences were observed either in fatigue behavior and removal torque between the different abutment groups. Conclusions: Mechanical behavior of Zireal zirconia abutments is independent of the type of internal/external connection and the presence/absence of ceramic coating. This may be clinically valuable in dental rehabilitation to improve the aesthetic outcome of zirconia-based dental implant systems. Key words:Dental implant, zirconia, ceramic structure, mechanical properties.

Jiménez-Melendo, Manuel; Llena-Blasco, Oriol; Bruguera, August; Llena-Blasco, Jaime; Yáñez-Vico, Rosa-María; García-Calderón, Manuel; Vaquero-Aguilar, Cristina; Velázquez-Cayón, Rocío; Gutiérrez-Pérez, José-Luis

2014-01-01

85

Irradiation-induced microstructural change in helium-implanted single crystal and nano-engineered SiC  

NASA Astrophysics Data System (ADS)

Microstructural evolution induced by helium implantation and subsequent heavy ion irradiation has been investigated in single crystal and nano-engineered (NE) 3C SiC. Implantation with 65 keV He+ ions was performed at 277 °C, and the helium depth distribution was determined by elastic recoil detection analysis (ERDA). Transmission electron microscopy (TEM) could not resolve the presence of bubbles in any of the helium-implanted single crystal SiC. However, helium platelets and small dislocation loops (?50 nm in diameter) were observed in the single crystal sample with the highest implantation fluence after 1 h annealing at 700 °C. Following irradiation with 9 MeV Au3+ ions at 700 °C, no bubbles were observed in the helium-implanted single crystal SiC, regardless of helium fluence. For the helium-implanted NE SiC, subsequent irradiation with 9 MeV Au ions to a dose of 10 dpa at 700 °C resulted in the formation and growth of bubbles, and a bimodal helium bubble size distribution was observed at the highest helium concentration (8000 appm) in the NE SiC.

Chen, C. H.; Zhang, Y.; Fu, E.; Wang, Y.; Crespillo, M. L.; Liu, C.; Shannon, S.; Weber, W. J.

2014-10-01

86

Rutherford backscattering and nuclear reaction analyses of hydrogen ion-implanted ZnO bulk single crystals  

NASA Astrophysics Data System (ADS)

The origins of low resistivity in H ion-implanted ZnO bulk single crystals are studied by Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA) photoluminescence (PL), and Van der Pauw methods. The H-ion implantation (peak concentration: 1.45 × 1020 cm-3) into ZnO is performed using a 500 keV implanter. The resistivity decreases from 2.5 × 103 ? cm for unimplanted ZnO to 6.5 ? cm for as-implanted one. RBS measurements show that Zn interstitial as a shallow donor is not recognized in as-implanted samples. From photoluminescence measurements, the broad green band emission is observed in as-implanted samples. NRA measurements for as-implanted ZnO suggest the existence of the oxygen interstitial. The origins of the low resistivity in the as-implanted sample are attributed to both the H interstitial as a shallow donor and complex donor between H and disordered O. The activation energy of H related donors estimated from the temperature dependence of carrier concentration is 29 meV.

Kaida, T.; Kamioka, K.; Ida, T.; Kuriyama, K.; Kushida, K.; Kinomura, A.

2014-08-01

87

Towards a single-chip, implantable RFID system: is a single-cell radio possible?  

PubMed Central

We present an overview of progress towards single-chip RFID solutions. To date heterogeneous integration has been appropriate for non-biological systems. However, for in-vivo sensors and even drug delivery systems, a small form factor is required. We discuss fundamental limits on the size of the form factor, the effect of the antenna, and propose a unified single-chip RFID solution appropriate for a broad range of biomedical in-vivo device applications, both current and future. Fundamental issues regarding the possibility of single cell RF radios to interface with biological function are discussed. PMID:19169827

Rutherglen, Christopher

2009-01-01

88

Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO  

E-print Network

As the intrinsic origin of the high temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn1?xFexO phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900 ?C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn substitutional sites behave as localized paramagnetic moments down to 2 K, irrespective of the Fe concentration and the density of beam-induced defects....

Pereira, Lino Miguel da Costa; Correia, João Guilherme; Van Bael, M J; Temst, Kristiaan; Vantomme, André; Araújo, João Pedro

2013-01-01

89

Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO  

NASA Astrophysics Data System (ADS)

As the intrinsic origin of the high-temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn1-xFexO phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900?° C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn-substitutional sites behave as localized paramagnetic moments down to 2 K, irrespective of the Fe concentration and the density of beam-induced defects. With increasing local concentration of Zn-substitutional Fe, strong nearest-cation-neighbor antiferromagnetic interactions favor the antiparallel alignment of the Fe moments.

Pereira, L. M. C.; Wahl, U.; Correia, J. G.; Van Bael, M. J.; Temst, K.; Vantomme, A.; Araújo, J. P.

2013-10-01

90

Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO.  

PubMed

As the intrinsic origin of the high-temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn(1-x)Fe(x)O phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900 ° C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn-substitutional sites behave as localized paramagnetic moments down to 2 K, irrespective of the Fe concentration and the density of beam-induced defects. With increasing local concentration of Zn-substitutional Fe, strong nearest-cation-neighbor antiferromagnetic interactions favor the antiparallel alignment of the Fe moments. PMID:24025311

Pereira, L M C; Wahl, U; Correia, J G; Van Bael, M J; Temst, K; Vantomme, A; Araújo, J P

2013-10-16

91

Surface morphology, thermal and electrical conductivity of ?-Al2O3 single crystals implanted with Au and Ag ions  

NASA Astrophysics Data System (ADS)

With the aim to study the effects of heavy ion implantation on the morphology of ?-Al2O3 single crystals with c, m and r orientations, ion implantation at room temperature, with Au or Ag ions, energy of 160 keV and fluences ranging from 5 × 1015 to 1 × 1017 ions cm-2 was performed. The microstructure and morphology of irradiated surfaces were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The presence of metal precipitates was explored by AFM and monitored by the variation of the intensity of the extinction bands associated with Mie scattering from Au and Ag colloids located at about 2.2 eV (563 nm) and 2.8 eV (443 nm), respectively. The results show a dependence on the surface roughness with the ion fluence and the implantation orientation. The dependence of thermal conductivity with the implanted conditions was studied by scanning thermal microscopy. Thermal images indicate that thermal conductivity of Al2O3 is higher in samples implanted with Ag ions at a fluence of 6 × 1016 ions cm-2 than in samples implanted with Au at a higher fluence. Successive etchings of an Ag implanted sample reveal a dependence of the thermal conductivity with the distance to the surface due to the layered damage structure produced by the implantation. The DC electrical measurements, between 273 and 445 K, using the four and two-point probe methods were used to characterize the electrical conductivity of the implanted area. The I-V characteristic of the electrical contacts reveals an ohmic behavior, independent of the ions implanted and the crystallographic orientation. Measurements of the electrical conductivity at different temperatures in the investigated range predominantly suggest a band conduction mechanism thermally activated, with energies of about 0.09 and 0.07 eV, in samples implanted with Au or Ag ions, respectively. We conclude that the enhancement in conductivity observed in the implanted regions is related to the intrinsic defects created by the implantation, rather than to the implanted Au and Ag ions.

Savoini, B.; Tardío, M. M.; Ramírez, R.; Alves, E.

2012-09-01

92

Single-Port Parastomal Hernia Repair by Using 3-D Textile Implants  

PubMed Central

Background: Parastomal hernias (PSHs) are a frequent complication and remain a surgical challenge. We present a new option for single-port PSH repair with equilateral stoma relocation using preshaped, prosthetic 3-dimensional implants and flat mesh insertion in intraperitoneal onlay placement for additional augmentation of the abdominal wall. Methods: We describe our novel technique in detail and performed an analysis of prospectively collected data from patients who underwent single-port PSH repair, focusing on feasibility, conversions, and complications. Results: From September 2013 to January 2014, 9 patients with symptomatic PSHs were included. Two conversions to reduced-port laparoscopy using a second 3-mm trocar were required because of difficult adhesiolysis, dissection, and reduction of the hernia sac content. No major intra- or postoperative complications or reoperations were encountered. One patient incurred a peristomal wound healing defect that could be treated conservatively. Conclusion: We found that single-port PSH repair using preshaped, elastic 3-dimensional devices and additional flat mesh repair of the abdominal wall is feasible, safe, and beneficial, relating to optimal coverage of unstable stoma edges with wide overlap to all sides and simultaneous augmentation of the midline in the IPOM technique. The stoma relocation enables prolapse treatment and prevention. The features of a modular and rotatable multichannel port system offer benefits in clear dissection ongoing from a single port. Long-term follow-up data on an adequate number of patients are awaited to examine efficacy. PMID:25392655

Emmanuel, Klaus; Schrittwieser, Rudolf

2014-01-01

93

A Prospective Study of Early Loaded Single Implant-Retained Mandibular Overdentures: Preliminary One-Year Results  

PubMed Central

Purpose. To investigate the predictability of simplifying mandibular overdenture treatment using one-stage surgery and early prosthetic loading of a single implant. Materials and Methods. Twenty edentulous patients with problematic existing mandibular dentures were treated. A single implant with a chemically modified surface (SLActive, Straumann AG, Basel, Switzerland) was placed into the mandibular midline. The patients were recalled at 3, 6 and 12 months. Clinical assessments and marginal bone loss using standardized radiographs were recorded. All complications, failures and maintenance were noted. Visual analog-scale questionnaires were used to record patient satisfaction in five categories. ANOVA was used to determine differences between means of marginal bone loss and different categories of patient staisfaction (P = 0.05). Results. The 20 early loaded implants were all surviving at the 12-month recall. All implants showed less than 1?mm of marginal bone loss by the end of the 1-year with a significant increase during the follow-up period. Few prosthetic problems were reported. Patient satisfaction was high with a significant increase in all comfort and functional parameters. Conclusions. These preliminary 1-year results indicate that early loading of a single chemically modified surface implant used to retain a mucosa-borne mandibular overdenture is a safe, reliable, and cost-effective treatment. PMID:22505895

El-Sheikh, Ali M.; Shihabuddin, Omar F.; Ghoraba, Sahar M. F.

2012-01-01

94

Neuronavigation-assisted single transseptal catheter implantation and shunt in patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatation  

PubMed Central

Background: To assess the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation by employing a single biventricular neuronavigation-assisted transseptal-implanted catheter with programmable valve and distal peritoneal derivation. Methods: A neuronavigation-assisted single transseptal biventricular catheter implantation with distal peritoneal shunt system was performed in 11 patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatations between 2001 and 2010. Patients with concomitant third ventricle dilatation were excluded. Several sequential frustrated attempts of temporary drainage occlusion on both sides confirmed the isolation of the lateral ventricles. Neuronavigation was employed to accurately establish the catheter surgical corridor (trajectory) across the lateral ventricles and throughout the septum pellucidum. The neurological and radiological outcomes were assessed at least 6 months after the procedure. Results: Catheter implantation was successfully performed in all patients. Only one catheter was found to be monoventricular on delayed computer tomography controls. Procedure-related complications (bleeding of infections) were not observed. No additional neurological deficits were found after shunt surgery. Six months after procedure, none required additional ventricular catheter implantations or shunt revisions. Radiological and clinical controls confirmed the shunt function and the improved neurological status of all patients. Conclusion: Single neuronavigation-assisted transseptal-implanted biventricular catheter is a valid option for the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation. This technique reduces the number of catheters and minimizes the complexity and timing of the surgical procedure as well as potential infection's risks associated with the use of multiple shunting systems. PMID:21541201

Carvi Nievas, Mario N.

2011-01-01

95

Quantification of in vivo implant wear in total knee replacement from dynamic single plane radiography  

NASA Astrophysics Data System (ADS)

An in vivo method to measure wear in total knee replacements was developed using dynamic single-plane fluoroscopy. A dynamic, anthropomorphic total knee replacement phantom with interchangeable, custom-fabricated components of known wear volume was created, and dynamic imaging was performed. For each frame of the fluoroscopy data, the relative location of the femoral and tibial components were determined, and the apparent intersection of the femoral component with the tibial insert was used to calculate wear volume, wear depth, and frequency of intersection. No difference was found between the measured and true wear volumes. The precision of the measurements was ±39.7 mm3 for volume and ±0.126 mm for wear depth. The results suggest the system is capable of tracking wear volume changes across multiple time points in patients. As a dynamic technique, this method can provide both kinematic and wear measurements that may be useful for evaluating new implant designs for total knee replacements.

Teeter, Matthew G.; Seslija, Petar; Milner, Jaques S.; Nikolov, Hristo N.; Yuan, Xunhua; Naudie, Douglas D. R.; Holdsworth, David W.

2013-05-01

96

Quantification of in vivo implant wear in total knee replacement from dynamic single plane radiography.  

PubMed

An in vivo method to measure wear in total knee replacements was developed using dynamic single-plane fluoroscopy. A dynamic, anthropomorphic total knee replacement phantom with interchangeable, custom-fabricated components of known wear volume was created, and dynamic imaging was performed. For each frame of the fluoroscopy data, the relative location of the femoral and tibial components were determined, and the apparent intersection of the femoral component with the tibial insert was used to calculate wear volume, wear depth, and frequency of intersection. No difference was found between the measured and true wear volumes. The precision of the measurements was ±39.7 mm(3) for volume and ±0.126 mm for wear depth. The results suggest the system is capable of tracking wear volume changes across multiple time points in patients. As a dynamic technique, this method can provide both kinematic and wear measurements that may be useful for evaluating new implant designs for total knee replacements. PMID:23552105

Teeter, Matthew G; Seslija, Petar; Milner, Jaques S; Nikolov, Hristo N; Yuan, Xunhua; Naudie, Douglas D R; Holdsworth, David W

2013-05-01

97

Micromachined piezoresistive proximal probe with integratedbimorph actuator for aligned single ion implantation  

SciTech Connect

The authors report a microfabrication procedure ofself-actuated piezoresistive scanning probes (SAPSPs). They are designedfor a SAPSP instrument that is integrated with an ion beam for alignedsingle ion implantation in ultrahigh vacuum. The novelty of the design isan integrated hollow pyramid, instead of a previously mechanically handmounted pyramid [J. Vac. Sci. Technol. B 23, 2798 (2005)]. Thepyramidhas dual purpose. First it collimates the ion beam and suppressessecondary particles from the back side of the cantilever, so thatsecondary particles from the target material can be used for single iondetection. Second the pyramid also provides an atomic force microscopetip for the scanning probe. A crucial step in the fabrication is the backside opening via etching for the hollow pyramid. The fabricationprocedure will be discussed in detail.

Persaud, A.; Ivanova, K.; Sarov, Y.; Ivanov, Tzv.; Volland, B.E.; Rangelow, I.W.; Nikolov, N.; Schenkel, T.; Djakov, V.; Jenkins, D.W.K.; Meijer, J.; Vogel, T.

2006-10-01

98

Single dental implant retained mandibular complete dentures – influence of the loading protocol: study protocol for a randomized controlled trial  

PubMed Central

Background Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading. Methods/design This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1). Discussion This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice. Trial registration The trial has been registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00003730 since 23 August 2012. (http://www.germanctr.de). PMID:24884848

2014-01-01

99

Outcomes of Single Segment Implantation of Conventional Intacs versus Intacs SK for Keratoconus  

PubMed Central

Purpose: To compare the visual, refractive, and keratometric outcomes of single-segment conventional and severe keratoconus (SK) types of Intacs for correction of inferior keratoconus (KCN). Methods: A total number of 41 consecutive eyes of 23 patients with a diagnosis of inferior KCN underwent Intacs implantation. Eight eyes were excluded due to postoperative complications (4 eyes) and loss to follow-up (4 eyes) and finally 33 eyes underwent statistical analysis. Two groups were created according to Intacs type insertion; conventional group (17 eyes) and SK groups (16 eyes). Intracorneal ring segments (ICRS) implantation was indicated in keratoconic patients with contact-lens intolerance or reduced best spectacle-corrected visual acuity (BSCVA). Results: In the conventional group, mean uncorrected distance visual acuity (UCDVA) improved from 0.45 ± 0.41 preoperatively to 0.69 ± 0.39 six months after surgery representing a gain of 2 Snellen lines, and in the SK group mean UCDVA changed from 0.40 ± 0.35 preoperatively to 0.58 ± 0.48 equivalent to two Snellen lines improvement 6 months after operation (P = 0.48). Mean preoperative BSCVA in the conventional group improved from 0.72 ± 0.41 to 0.86 ± 0.39 (2 lines improvement) postoperatively and in the SK group improved from 0.71 ± 0.69 to 0.75 ± 0.45 (0.50 line improvement) (P = 0.29). Mean preoperative spherical equivalent (SE) decreased from ?4.86 ± 2.26 D to ?3.57 ± 2.21 D (conventional group) and from ?4.20 ± 1.82 D to ?3.60 ± 1.89 D (P = 0.34), mean astigmatism (AST) decreased from ?5.20 ± 2.07 D and ?4.50 ± 2.26 D to ?4.02 ± 2.57 D and ? 3.18 ± 2.14 D in the conventional and SK groups, respectively (P = 0.68). Finally, mean K min decreased from 47.11 ± 2.51 D to 45.40 ± 3.30 D in the conventional group and from 45.05 ± 2.59 D to 44 ± 3.88 D in the SK group (P = 0.63) and mean K max was decreased from 52.82 ± 3.23 D to 50.52 ± 3.57 D and from 49.72 ± 3.17 D to 48.55 ± 4.50 D, respectively (P = 0.48). Conclusion: Single-segment implantation of conventional and SK Intacs improved UCDVA and BSCVA, decreased corneal AST and keratometry in both groups with comparable outcomes.

Hashemian, Mohammad Nasser; Zare, Mohammad Ali; Mohammadpour, Mehrdad; Rahimi, Firouzeh; Fallah, Mohammad Reza; Panah, Fereydoun Keramat

2014-01-01

100

Posterior implants for distal extension removable prostheses: a retrospective study.  

PubMed

Common complaints associated with the Kennedy Class I (bilateral free end) and Class II (unilateral free end) removable partial denture situations are lack of stability, minimal retention, and unesthetic retentive clasping. Some of the same complaints have been reported for implant overdentures with only anterior implants. Starting in 1995, 10 of these patients were treated at the University of Washington with posterior osseointegrated implants to provide stability and/or retention of the removable prostheses, eliminating the need for clasps when possible. This article describes implant alternatives and prosthesis designs and presents a follow-up clinical evaluation of at least 1 year consisting of patient satisfaction, radiographic examination, and soft tissue health. Two groups were evaluated. Group 1 included patients whose implants were used as vertical stops for mandibular distal extension prostheses. Care was taken to ensure that the implants were not loaded laterally by creating a single-point contact at the center of a modified healing abutment. In these cases, sufficient retention was available from the anterior teeth and/or implant abutments. Group 2 included patients whose implants required retention because of lack of adequate tooth abutments. In those cases, a resilient type of attachment was used, which allowed for a small divergence from the path of insertion. Results indicated consistent increased satisfaction in all patients, minimal component wear, no radiographic evidence of excessive bone loss, and stable peri-implant soft tissues. PMID:12956479

Mitrani, Ricardo; Brudvik, James S; Phillips, Keith M

2003-08-01

101

Fracture resistance of implant-supported screw- versus cement-retained porcelain fused to metal single crowns: SEM fractographic analysis  

Microsoft Academic Search

ObjectivesThe present in vitro study aimed at evaluating the fracture resistance of both implant-supported screw- and cement-retained porcelain fused to metal (PFM) single crowns. A scanning electron microscope (SEM) evaluation of the mode of failure of the specimens was also performed.

Fernando Zarone; Roberto Sorrentino; Tonino Traini; Donato Di lorio; Sergio Caputi

2007-01-01

102

Improvement of depth position in 2-D\\/3-D registration of knee implants using single-plane fluoroscopy  

Microsoft Academic Search

Two-dimensional (2-D)\\/three-dimensional (3-D) reg- istration techniques using single-plane fluoroscopy are highly im- portant for analyzing 3-D kinematics in applications such as total knee arthroplasty (TKA) implants. The accuracy of single-plane fluoroscopy-based techniques in the determination of translation perpendicular to the image plane (depth position), however, is rel- atively poor because a change in the depth position causes only small changes

Takaharu Yamazaki; Tetsu Watanabe; Yoshikazu Nakajima; Kazuomi Sugamoto; Tetsuya Tomita; Hideki Yoshikawa; Shinichi Tamura

2004-01-01

103

Preliminary three-dimensional analysis of tooth movement and arch dimension change of the maxillary dentition in Class II division 1 malocclusion treated with first premolar extraction: conventional anchorage vs. mini-implant anchorage  

PubMed Central

Objective This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 (2.6°, 2.5°, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth. PMID:23323242

Park, Heon-Mook; Kim, Byoung-Ho; Yang, Il-Hyung

2012-01-01

104

Immediate loading of an implant following implant site development using forced eruption: a case report.  

PubMed

In restoring periodontally involved hopeless teeth, implant treatment has been widely used with combinations of various grafting techniques or guided bone regeneration. Instead of traditional surgical procedures, forced tooth eruption may be used successfully for implant site development. In this case, the authors orthodontically erupted a hopeless central incisor with an angular bony defect. Subsequently, they placed an implant immediately after tooth extraction and immediately loaded it with a temporary resin restoration. PMID:16161747

Park, Young-Seok; Yi, Ki-Young; Moon, Seong-Cheol; Jung, Young-Chul

2005-01-01

105

Clinical decision making regarding endodontics versus implants.  

PubMed

This article discusses the current considerations in treatment planning for retention of the natural tooth through endodontic therapy (including orthograde first-time treatment, retreatment, and endodontic surgery) versus extraction and placement of a dental implant. As a secondary goal, the article describes several specific cases in which the best option is either an implant or retention of the natural tooth. The issue of tooth retention versus implant therapy is also addressed with regard to the specific clinical diagnosis of resorption in all of its various forms. Emphasis has been placed on practical strategies for treatment of cases involving internal and external root resorption using a comprehensive evidence-based approach. PMID:21661658

Derhalli, Munib; Mounce, Richard E

2011-05-01

106

Origins of low resistivity and Ge donor level in Ge ion-implanted ZnO bulk single crystals  

SciTech Connect

The energy level of Ge in Ge-ion implanted ZnO single crystals is studied by Hall-effect and photoluminescence (PL) methods. The variations in resistivity from ?10{sup 3} ?cm for un-implanted samples to ?10{sup ?2} ?cm for as-implanted ones are observed. The resistivity is further decreased to ?10{sup ?3} ?cm by annealing. The origins of the low resistivity are attributed to both the zinc interstitial (Zn{sub i}) related defects and the electrical activated Ge donor. An activation energy of Ge donors estimated from the temperature dependence of carrier concentration is 102 meV. In PL studies, the new peak at 372 nm (3.33 eV) related to the Ge donor is observed in 1000 °C annealed samples.

Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan)

2013-12-04

107

The Kaiser's tooth.  

PubMed

The recovery of DNA from teeth is usually associated with the destruction of the evidential tooth using, for instance a special grinding mill. In some cases, however, a minimal invasive method of DNA retrieval with a high recovery is required particularly when historical material has to be investigated. A tooth attributed to the German Emperor Wilhelm II was the only source of DNA in an analysis of a possible paternity and the DNA had to be extracted without destroying the appearance of the tooth. Here, the results of the DNA analysis are presented. PMID:12690510

Pfeiffer, H; Benthaus, S; Rolf, B; Brinkmann, B

2003-04-01

108

Thermal exfoliation and crystallographic transformation of single-crystal metal oxides induced by He-ion implantation  

NASA Astrophysics Data System (ADS)

We report on the thermal exfoliation of 7 ?m thick films from 3.8 MeV He ion-implanted single-crystal 0.955 Pb(Zn1/3Nb2/3)O3-0.045 PbTiO3 [(PZN-PT) with 4.5% PT] by rapid thermal processing. Comparison with z-cut LiNbO3 shows a significantly higher exfoliation threshold temperature in PZN-PT for the same implantation conditions. Unusually large strains in the through-implanted layer are induced in the relaxor ferroelectric PZN-PT upon ion implantation leading to a crystallographic phase transformation in that material that is not observed in LiNbO3. Depth profile analysis of the refractive index shows a much larger refractive index modulation due to nuclear collisions than in LiNbO3. The higher exfoliation temperature observed for PZN-PT, despite a larger impact of the ion implantation on material structure, suggests that the electronic polarizability and elastic response of relaxor ferroelectrics near the morphotropic phase boundary have a significant impact on the crack propagation process responsible for thermally induced exfoliation.

Moran, P. D.; Levy, M.

2003-09-01

109

Advanced predoctoral implant program at UIC: description and qualitative analysis.  

PubMed

Dental implant education has increasingly become an integral part of predoctoral dental curricula. However, the majority of implant education emphasizes the restorative aspect as opposed to the surgical. The University of Illinois at Chicago College of Dentistry has developed an Advanced Predoctoral Implant Program (APIP) that provides a select group of students the opportunity to place implants for single-tooth restorations and mandibular overdentures. This article describes the rationale, logistics, experiences, and perspectives of an innovative approach to provide additional learning experiences in the care of patients with partial and complete edentulism using implant-supported therapies. Student and faculty perspectives on the APIP were ascertained via focus group discussions and a student survey. The qualitative analysis of this study suggests that the select predoctoral dental students highly benefited from this experience and intend to increase their knowledge and skills in implant dentistry through formal education following graduation. Furthermore, the survey indicates that the APIP has had a positive influence on the students' interest in surgically placing implants in their future dental practice and their confidence level in restoring and surgically placing implants. PMID:24789837

Afshari, Fatemeh S; Yuan, Judy Chia-Chun; Quimby, Anastasiya; Harlow, Rand; Campbell, Stephen D; Sukotjo, Cortino

2014-05-01

110

Soft tissue stability with immediate implants and concave abutments.  

PubMed

Implant therapy success in the anterior maxilla is judged not only by osseointegration, but also by having sound and stable peri-implant tissues that appear identical to the gingiva surrounding the healthy adjacent teeth. The creation of predictable peri-implant esthetics requires proper preservation of the osseous and soft tissues surrounding the failing teeth, proper three-dimensional implant placement, and proper understanding of prosthetic management. It is now possible to place immediate implants and immediate prostheses to improve esthetics and to simplify treatment, but this technique does not seem to have a stable long-term buccal mucosa. To avoid or reduce this negative effect it appears to be important to increase the thickness of the buccal tissues, and to use appropriate implant components. The aim of the present retrospective study was to observe the dimensional alterations of the peri-implant tissues after immediate implants and single-tooth restorations with concave abutments performed on 28 patients, with a mean followup time of 20.4 months. PMID:20111758

Redemagni, Marco; Cremonesi, Sergio; Garlini, Giuliano; Maiorana, Carlo

2009-01-01

111

Flapless implant surgery in the esthetic region: advantages and precautions.  

PubMed

Because osseointegration is now considered highly predictable, the current trend is to develop techniques that can provide function, esthetics, and comfort with a minimally invasive surgical approach. To achieve those goals, flapless implant surgery using a tissue punch technique has been suggested. This paper presents two clinical cases of single-tooth implants placed in the esthetic region (anterior maxilla), which illustrate systematic approaches to flapless implant surgery for immediate and delayed loading protocol. For both cases, a tissue punch technique using a surgical guide fabricated with the aid of a radiographic stent was performed to provide access for implant site preparation and placement. The implants were loaded either immediately or 4 months after implant placement. With the planned flapless surgical technique, reduced operative time, accelerated postsurgical healing, and increased patient comfort and satisfaction were achieved. This paper also describes precautions of the flapless implant surgery in case selection, surgical techniques, and prosthodontic protocol. In conclusion, appropriate case selection and well-tailored surgical guides with sound surgical and prosthodontic protocols are considered to be the key elements in the success of flapless implant surgery. PMID:17370659

Oh, Tae-Ju; Shotwell, Jeffrey; Billy, Edward; Byun, Ho-Young; Wang, Hom-Lay

2007-02-01

112

Tooth Abfraction Lesions  

MedlinePLUS

... Choices include a composite material or glass ionomer cement . A tooth with abfraction lesions may be more ... need treatment. For others, filling the areas with cement or composite solves the problem. Additional Info American ...

113

Allogenous tooth fragment reattachment.  

PubMed

Coronal fractures of the anterior teeth are a common form of dental trauma and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. Among the various treatment options, reattachment of a crown fragment obtained from a previously extracted tooth is a conservative treatment that should be considered for crown fractures of anterior teeth. This article reports reattachment of an allogenous tooth fragment in a fractured maxillary lateral incisor in a 38-year-old patient. It is suggested that allogenous reattachment in a fractured anterior tooth serves to be a better alternative and should be further researched. Aesthetic and functional rehabilitation of a fractured complicated anterior crown using allogenous tooth fragment is a better alternative to other more conventional treatment options. PMID:23845684

Maitin, Nitin; Maitin, Shipra; Rastogi, Khushboo; Bhushan, Rajarshi

2013-01-01

114

Cracked Tooth Syndrome  

MedlinePLUS

... your teeth, talk to your dentist about treatment. Grinding can increase your risk of cracked tooth syndrome. ... a plastic bite piece) to prevent you from grinding your teeth. This will relieve the pain from ...

115

Fracture tooth fragment reattachment.  

PubMed

Coronal fractures of the anterior teeth are a common form of dental trauma and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. Among the various treatment options, reattachment of a crown fragment is a conservative treatment that should be considered for crown fractures of anterior teeth. This clinical case reports the management of two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment using glass-fibre-reinforced composite post. PMID:23853012

Maitin, Nitin; Maitin, Shipra Nangalia; Rastogi, Khushboo; Bhushan, Rajarshi

2013-01-01

116

Genes affecting tooth morphogenesis.  

PubMed

The development of dentition is a fascinating process that encompasses a complex series of epithelial-mesenchymal interactions involving growth factors, transcription factors, signal receptors and other soluble morphogens. It is not surprising that such a complex process is prone to disturbances and may result in tooth agenesis. Initial discoveries indicating that the homeo-domain protein MSX1 and the paired-domain transcription factor PAX9 are causative genes in tooth morphogenesis were made in mice. Both genes are co-expressed in dental mesenchyme and either one, when homozygously deleted, results in an arrest at an early developmental stage. Heterozygous Pax9 or Msx1 mice have normal teeth, however, double heterozygous Pax9/Msx1 mice show a phenotype of arrested tooth development which can be rescued by transgenic expression of Bmp4, a very influential signaling factor in many developmental processes. We have obtained mounting evidence for a partnership between PAX9 and MSX1 within the tooth-specific Bmp4 signaling pathway. In humans, unlike in mice, a heterozygous mutation in either PAX9 or MSX1 suffices to cause tooth agenesis of a predominantly molar or more premolar pattern, respectively. Our laboratory and others have identified several PAX9 and MSX1 mutations in families with non-syndromic forms of autosomal dominant posterior tooth agenesis. We have also identified families with tooth agenesis in whom PAX9 and MSX1 mutations have been excluded opening up the possibilities for the discovery of other genes that contribute to human tooth agenesis. PMID:17651126

Kapadia, H; Mues, G; D'Souza, R

2007-08-01

117

Metagenomic analysis of the peri-implant and periodontal microflora in patients with clinical signs of gingivitis or mucositis.  

PubMed

The long-term success of osseointegrated oral implants is endangered by inflammation of peri-implant hard and soft tissues caused by bacterial biofilms that may have been initiated by bacterial transmission from the adjacent dentition. The present study aimed to compare the bacterial communities at inflamed implant and tooth sites by broad-range PCR techniques to evaluate the etiological processes of peri-implant and periodontal diseases and potential future therapeutic strategies. Eighteen samples of peri-implant and periodontal microflora were collected from nine partially edentulous patients with implant-retained crowns or bridges revealing clinical signs of gingivitis or mucositis. The clinical parameters plaque index (PI), probing depth (PD), and bleeding on probing were recorded. Amplified fragments of bacterial 16S rRNA genes were separated by use of single-strand conformation polymorphism analysis, and sequences were determined to identify the predominant bacterial genera. The clinical parameters PI and PD were significantly different at implants (PI = 0.4 ± 0.7, PD = 3.1 ± 0.6 mm) compared with teeth (PI = 1.8 ± 0.8, PD = 2.5 ± 0.2 mm). A total of 20 different genera were found at the inflamed tooth and implant sites. The microbial diversity of the microflora surrounding the remaining dentition (12.0 ± 3.8) was significantly higher (p = 0.01) than the diversity of the peri-implant microflora at implant-retained crowns or bridges (6.3 ± 2.3). Within the limitations of the present study, the microbial diversity of the investigated implants and teeth with clinical signs of mucositis or gingivitis exhibits substantial differences, demonstrating that transmission of the complete bacterial microflora from teeth to implants could be excluded. Furthermore, broad-range molecular biological detection methods specify bacterial genera and species in the peri-implant and periodontal microflora which were not in the focus of research interests so far. PMID:21538072

Heuer, Wieland; Kettenring, Andreas; Stumpp, Sascha Nico; Eberhard, Jörg; Gellermann, Eva; Winkel, Andreas; Stiesch, Meike

2012-06-01

118

Two cross-linked porcine dermal implants in a single patient undergoing hernia repair  

PubMed Central

A 50-year-old woman with a history of multiple recurrent incisional hernias and multiple comorbidities received two different porcine dermal implants during the same procedure due to the availability of products in stock. At 3.5?months following this procedure, the patient developed a secondary hernia inferior and lateral to the site of previous surgery. Both the implants were biopsied and sent for pathological evaluation. One implant was compliant and well integrated while the other was non-compliant and exhibited extensive foreign body reaction. In this case report, we examine the differences between the two porcine implants that may have caused them to react so differently in the same subject under the same conditions. PMID:23345480

Linz, Luke A; Burke, Leandra H; Miller, Lisa A

2013-01-01

119

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws  

PubMed Central

PURPOSE To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. CONCLUSION In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results. PMID:25177466

2014-01-01

120

Advantages and Disadvantages of Double Threaded Dental Implant Screws As Opposed to Single-Threaded: A Study from a Biomechanical Perspective by the Finite Element Method  

NASA Astrophysics Data System (ADS)

The purpose of the present article is to study the advantages from a biomechanical point of view of the use of a double-threaded dental implant over the more common single-threaded one. For this purpose a 3D model of a portion of the jaw was generated. In this model four different bone areas were distinguished (transition cortical, transition trabecular, bulk cortical and bulk trabecular). Not only was the portion of the jaw created with CAD software but also two different implants geometries, one with only one thread (single-threaded) and the other with two threads (double-threaded). The loading condition was defined as 150 N intrusive forces and 15 N lingual-labial forces acting on the implant. The results of the present study shown that from a macroscopic point of view, the choice of one or other of the dental implants does not make a significant difference in the general behaviour of the jaw. In spite of this and notwithstanding the effects of the transition bone-implant, the stress distribution achieved by the single-threaded dental implant is more uniform. This effect is better for the biomechanics of the jaw. The advantage presented by the double threaded implant is that due to its larger surface the osseointegration is better than in the single-threaded version.

Álvarez-Arenal, A.; de Cos Juez, F. J.; Lasheras, F. Sánchez; Quevedo, M. Mauvezin

2009-08-01

121

A procedure for implanting organized arrays of microwires for single-unit recordings in awake, behaving animals.  

PubMed

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell level. The technique allows experimenters to examine temporally and regionally specific firing patterns in order to correlate recorded action potentials with ongoing behavior. Moreover, single-unit recordings can be combined with a plethora of other techniques in order to produce comprehensive explanations of neural function. In this article, we describe the anesthesia and preparation for microwire implantation. Subsequently, we enumerate the necessary equipment and surgical steps to accurately insert a microwire array into a target structure. Lastly, we briefly describe the equipment used to record from each individual electrode in the array. The fixed microwire arrays described are well-suited for chronic implantation and allow for longitudinal recordings of neural data in almost any behavioral preparation. We discuss tracing electrode tracks to triangulate microwire positions as well as ways to combine microwire implantation with immunohistochemical techniques in order to increase the anatomical specificity of recorded results. PMID:24561332

Barker, David J; Root, David H; Coffey, Kevin R; Ma, Sisi; West, Mark O

2014-01-01

122

Short-term evaluation of dental implants in a diabetic population: an in vivo study  

PubMed Central

PURPOSE The study was conducted to evaluate the efficacy of implant supported tooth replacement in diabetic patients. MATERIALS AND METHODS The study involved placement of implants (UNITI implants, Equinox Medical Technologies, Zeist, Holland, diameter of 3.7 mm and length 13 mm) in five diabetic patients (three females and two males) of age ranging from 35-65 years with acceptable metabolic control of plasma glucose. All patients included in the study were indicated for single tooth maxillary central incisor replacement, with the adjacent teeth intact. The survival of the restored implants was assessed for a period of three months by measurement of crestal bone heights, bleeding on probing and micro flora predominance. Paired t-test was done to find out the difference in the microbial colonization, bleeding on probing and crestal bone loss. P values of less than 0.05 were taken to indicate statistical significance. RESULTS Results indicated that there was a significant reduction in bleeding on probing and colonization at the end of three months and the bone loss was not statistically significant. CONCLUSION The study explores the hypothesis that patients with diabetes are appropriate candidates for implants and justifies the continued evaluation of the impact of diabetes on implant success and complications. PMID:22977720

Veeravalli, Padmanabhan Thallam; Vaidyanathan, Anand Kumar; Grover, Manita

2012-01-01

123

Clinical and Radiographic Evaluation of Brånemark Implants with an Anodized Surface following Seven-to-Eight Years of Functional Loading  

PubMed Central

The aim of this study was to evaluate the clinical and radiographic long-term outcomes of dental implants with an anodized TiUnite surface, placed in routine clinical practice. Two clinical centers participated in the study. One hundred and seven implants (80 in the maxilla and 27 in the mandible) in 52 patients were followed in the long term. Both one- and two-stage techniques were used for 38 and 69 implants, respectively. Thirty-eight single tooth restorations and 22 fixed partial prostheses were delivered, according to a delayed loading protocol, within 4 to 12 months since implant placement. All implants were stable at insertion and at the long-term follow-up visit, which occurred between 7 and 8 years of functional loading. The mean followup was 7.33 ± 0.47 years. The mean marginal bone level change at the long-term followup as compared to baseline was 1.49 ± 1.03?mm. No implant failure occurred. Healthy peri-implant mucosa was found around 95% of implants, whereas 91% of implants showed no visible plaque at the implant surfaces at the long-term followup. The study showed that dental implants with the TiUnite anodized surface demonstrate excellent long-term clinical and radiographic outcomes. PMID:23533412

Gelb, David; McAllister, Bradley; Nummikoski, Pirkka; Del Fabbro, Massimo

2013-01-01

124

Acoustic tooth cleaner  

NASA Technical Reports Server (NTRS)

An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

Heyman, J. S. (inventor)

1982-01-01

125

Current trends in dental implants  

PubMed Central

Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evolution of dental implants. It also describes the types of implants that have been developed, and the parameters that are presently used in the design of dental implants. Finally, it describes the trends that are employed to improve dental implant surfaces, and current technologies used for the analysis and design of the implants. PMID:24868501

Gaviria, Laura; Salcido, John Paul; Guda, Teja

2014-01-01

126

Using dental implants in the prosthetic rehabilitation of patients with cleft defect type II.  

PubMed

A dental implant may be used in prosthetic tooth reconstruction in cleft patients. There are three main indications for this approach: substitution of a missing single tooth, an abutment for the framework, and an abutment for a fixed dental prosthesis (we designate these as defect types I, II, and III). A clinical report about prosthetic rehabilitation using dental implants instead of a fixed or removable partial prosthesis is presented. A patient with a unilateral cleft defect was treated at the University Hospital in Prague, Czech Republic. Together with a missing lateral incisor, the defect was associated with agenesis of the two upper canines and three second premolars. The treatment was completed by prosthetic dental reconstruction using the framework with a dental implant as an abutment. This approach allowed minimizing the preparation of adjacent teeth to a single tooth functioning as the second abutment. If classical fixed prosthodontics had been performed, the preparation would have involved a larger group of intact teeth with the risk of their viability loss. The procedure had no complications. The outcome was of high quality and brought satisfaction to the patient. PMID:20500067

Sedlackova, Kristina; Duskova, Marketa; Strnadel, Tomas; Kotova, Magdalena; Haas, Michal

2011-01-01

127

The Rachitic Tooth  

PubMed Central

Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed. PMID:23939820

Nociti, Francisco H.; Somerman, Martha J.

2014-01-01

128

The rachitic tooth.  

PubMed

Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed. PMID:23939820

Foster, Brian L; Nociti, Francisco H; Somerman, Martha J

2014-02-01

129

Osseointegrated dental implants as alternative therapy to bridge construction or orthodontics in young patients: seven years of clinical experience  

Microsoft Academic Search

Young patients often require fixed bridgework or orthodontic therapy in cases of traumatic tooth loss or congenitally missing teeth. Dental implants represent an alternative to the more conventional treatment methods. We report positive experience over a seven-year period with 42 titanium Ha-Ti implants in 34 patients aged 9 to 18 years. Fourteen implants were placed into prepared tooth sockets immediately

Philippe D. Ledermann; Thomas M. Hassell; Arthur F. Hefti

1993-01-01

130

Tooth auto-transplantation as an alternative treatment option: A literature review  

PubMed Central

Rapidly evolving implantation and alveolar ridge reconstruction techniques created a new area in modern dentistry where tooth loss is no longer a problem. Endless variations of implant's length, diameter, surface, and design along with autogenous, alogenous, aloplastic, or xenogenous bone substitutes made it possible to recreate physiological occlusion, esthetic and masticatory function. However, none of nowadays technologies in implant dentistry have the potential to adapt to a growth and development changes of a child's jaw. Therefore, patient's young age is a restriction for implantation and a particular challenge for a dentist willing to restore missing tooth. Thus, tooth auto-transplantation can be a good choice for treatment. The objective of this review is to underline the biologic principles required for successful auto-transplantation of teeth. Limits, indications, technique, and prognosis will be analyzed. PMID:23878556

Nim?enko, Tatjana; Omerca, Gražvydas; Varinauskas, Vaidas; Bramanti, Ennio; Signorino, Fabrizio; Cicciù, Marco

2013-01-01

131

A Radiographic Comparison of Progressive and Conventional Loading on Crestal Bone Loss and Density in Single Dental Implants: A Randomized Controlled Trial Study  

PubMed Central

Objective: Crestal bone loss is a biological complication in implant dentistry. The aim of this study was to compare the effect of progressive and conventional loading on crestal bone height and bone density around single osseointegrated implants in the posterior maxilla by a longitudinal radiographic assessment technique. Materials and Methods: Twenty micro thread implants were placed in 10 patients (two implants per patient). One of the two implants in each patient was assigned to progressive and the other to conventional loading groups. Eight weeks after surgery, conventional implants were restored with a metal ceramic crown and the progressive group underwent a progressive loading protocol. The progressive loading group took different temporary acrylic crowns at 2, 4 and 6 months. After eight months, acrylic crowns were replaced with a metal ceramic crown. Computer radiography of both progressive and conventional implants was taken at 2, 4, 6, and 12 months. Image analysis was performed to measure the height of crestal bone loss and bone density. Results: The mean values of crestal bone loss at month 12 were 0.11 (0.19) mm for progressively and 0.36 (0.36) mm for conventionally loaded implants, with a statistically significant difference (P < 0.05) using Wilcoxon sign rank. Progressively loaded group showed a trend for higher bone density gain compared to the conventionally loaded group, but when tested with repeated measure ANOVA, the differences were not statistically significant (P > 0.05). Conclusion: The progressive group showed less crestal bone loss in single osseointegrated implant than the conventional group. Bone density around progressively loaded implants showed increase in crestal, middle and apical areas. PMID:23724215

Ghoveizi, Rahab; Alikhasi, Marzieh; Siadat, Mohammad-Reza; Siadat, Hakimeh; Sorouri, Majid

2013-01-01

132

Gear tooth topological modification  

NASA Technical Reports Server (NTRS)

The topology of parallel axis gears, such as spur and helical gears is modified to produce quieter and more smoothly operating gear sets with more uniform load distribution. A finite element analysis of the gear in its operating mode is made to produce a plot of radial and tangential deflections of the pinion and gear tooth surfaces which will occur when the gears are loaded during operation. The resultant plot is then inverted to produce a plot, or set of coordinates, which will define the path of travel of the gear tooth grinding wheel, which path is a mirror image of the plot of the finite element analysis. The resulting gears, when subjected to operating loads, will thus be deflected tangentially and radially to their optimum operating, or theoretical true involute, positions so as to produce quieter, smoother, and more evenly loaded gear trains.

Kish, Jules G. (Inventor); Isabelle, Charles (Inventor)

1994-01-01

133

Stream segregation on a single electrode as a function of pulse rate in cochlear implant listeners  

PubMed Central

While cochlear implants (CIs) usually provide high levels of speech recognition in quiet, speech recognition in noise remains challenging. To overcome these difficulties, it is important to understand how implanted listeners separate a target signal from interferers. Stream segregation has been studied extensively in both normal and electric hearing, as a function of place of stimulation. However, the effects of pulse rate, independent of place, on the perceptual grouping of sequential sounds in electric hearing have not yet been investigated. A rhythm detection task was used to measure stream segregation. The results of this study suggest that while CI listeners can segregate streams based on differences in pulse rate alone, the amount of stream segregation observed decreases as the base pulse rate increases. Further investigation of the perceptual dimensions encoded by the pulse rate and the effect of sequential presentation of different stimulation rates on perception could be beneficial for the future development of speech processing strategies for CIs. PMID:23231115

Duran, Sara I.; Collins, Leslie M.; Throckmorton, Chandra S.

2012-01-01

134

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

PubMed

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

2013-09-01

135

Two stage gear tooth dynamics program  

NASA Technical Reports Server (NTRS)

The epicyclic gear dynamics program was expanded to add the option of evaluating the tooth pair dynamics for two epicyclic gear stages with peripheral components. This was a practical extension to the program as multiple gear stages are often used for speed reduction, space, weight, and/or auxiliary units. The option was developed for either stage to be a basic planetary, star, single external-external mesh, or single external-internal mesh. The two stage system allows for modeling of the peripherals with an input mass and shaft, an output mass and shaft, and a connecting shaft. Execution of the initial test case indicated an instability in the solution with the tooth paid loads growing to excessive magnitudes. A procedure to trace the instability is recommended as well as a method of reducing the program's computation time by reducing the number of boundary condition iterations.

Boyd, Linda S.

1989-01-01

136

Tooth regeneration: a revolution in stomatology and evolution in regenerative medicine  

PubMed Central

A tooth is a complex biological organ and consists of multiple tissues including the enamel, dentin, cementum and pulp. Tooth loss is the most common organ failure. Can a tooth be regenerated? Can adult stem cells be orchestrated to regenerate tooth structures such as the enamel, dentin, cementum and dental pulp, or even an entire tooth? If not, what are the therapeutically viable sources of stem cells for tooth regeneration? Do stem cells necessarily need to be taken out of the body, and manipulated ex vivo before they are transplanted for tooth regeneration? How can regenerated teeth be economically competitive with dental implants? Would it be possible to make regenerated teeth affordable by a large segment of the population worldwide? This review article explores existing and visionary approaches that address some of the above-mentioned questions. Tooth regeneration represents a revolution in stomatology as a shift in the paradigm from repair to regeneration: repair is by metal or artificial materials whereas regeneration is by biological restoration. Tooth regeneration is an extension of the concepts in the broad field of regenerative medicine to restore a tissue defect to its original form and function by biological substitutes. PMID:21789959

Yildirim, Sibel; Fu, Susan Y; Kim, Keith; Zhou, Hong; Lee, Chang Hun; Li, Ang; Kim, Sahng Gyoon; Wang, Shuang; Mao, Jeremy J

2011-01-01

137

Tooth regeneration: a revolution in stomatology and evolution in regenerative medicine.  

PubMed

A tooth is a complex biological organ and consists of multiple tissues including the enamel, dentin, cementum and pulp. Tooth loss is the most common organ failure. Can a tooth be regenerated? Can adult stem cells be orchestrated to regenerate tooth structures such as the enamel, dentin, cementum and dental pulp, or even an entire tooth? If not, what are the therapeutically viable sources of stem cells for tooth regeneration? Do stem cells necessarily need to be taken out of the body, and manipulated ex vivo before they are transplanted for tooth regeneration? How can regenerated teeth be economically competitive with dental implants? Would it be possible to make regenerated teeth affordable by a large segment of the population worldwide? This review article explores existing and visionary approaches that address some of the above-mentioned questions. Tooth regeneration represents a revolution in stomatology as a shift in the paradigm from repair to regeneration: repair is by metal or artificial materials whereas regeneration is by biological restoration. Tooth regeneration is an extension of the concepts in the broad field of regenerative medicine to restore a tissue defect to its original form and function by biological substitutes. PMID:21789959

Yildirim, Sibel; Fu, Susan Y; Kim, Keith; Zhou, Hong; Lee, Chang Hun; Li, Ang; Kim, Sahng Gyoon; Wang, Shuang; Mao, Jeremy J

2011-07-01

138

The management of an endodontically abscessed tooth: patient health state utility, decision-tree and economic analysis  

PubMed Central

Background A frequent encounter in clinical practice is the middle-aged adult patient complaining of a toothache caused by the spread of a carious infection into the tooth's endodontic complex. Decisions about the range of treatment options (conventional crown with a post and core technique (CC), a single tooth implant (STI), a conventional dental bridge (CDB), and a partial removable denture (RPD)) have to balance the prognosis, utility and cost. Little is know about the utility patients attach to the different treatment options for an endontically abscessed mandibular molar and maxillary incisor. We measured patients' dental-health-state utilities and ranking preferences of the treatment options for these dental problems. Methods Forty school teachers ranked their preferences for conventional crown with a post and core technique, a single tooth implant, a conventional dental bridge, and a partial removable denture using a standard gamble and willingness to pay. Data previously reported on treatment prognosis and direct "out-of-pocket" costs were used in a decision-tree and economic analysis Results The Standard Gamble utilities for the restoration of a mandibular 1st molar with either the conventional crown (CC), single-tooth-implant (STI), conventional dental bridge (CDB) or removable-partial-denture (RPD) were 74.47 [± 6.91], 78.60 [± 5.19], 76.22 [± 5.78], 64.80 [± 8.1] respectively (p < 0.05). Their respective Willingness-to-Pay ($CDN) were 1,782.05 [± 361.42], 1,871.79 [± 349.44], 1,605.13 [± 348.10], 1,351.28 [± 368.62] (p < 0.05). The standard gamble utilities for the restoration of a maxillary central incisor with a CC, STI, CDB and RPD were 88.50 [± 6.12], 90.68 [± 3.41], 89.78 [± 3.81] and 91.10 [± 3.57] respectively (p > 0.05). Their respective willingness-to-pay ($CDN) were: 1,782.05 [± 361.42], 1,871.79 [± 349.44], 1,605.13 [± 348.10] and 1,351.28 [± 368.62]. A statistical difference was found between the utility of treating a maxillary central incisor and mandibular 1st-molar (p < 0.05). The expected-utility-value for a 5-year prosthetic survival was highest for the CDB and the STI treatment of an abscessed mandibular molar (74.75 and 71.47 respectively) and maxillary incisor (86.24 and 84.91 respectively). This held up to a sensitivity analysis when the success of root canal therapy and the risk of damage to the adjacent tooth were varied. The RPD for both the molar and incisor was the favored treatment based on a cost-utility (3.85 and 2.74 CND$ per year of tooth saved respectively) and cost-benefit analysis (0.92 to 0.60 CND$ of cost per $ of benefit, respectively) for a prosthetic clinical survival of 5-years. Conclusion The position of the abscessed tooth and the amount of insurance coverage influences the utility and rank assigned by patients to the different treatment options. STI and CDB have optimal EUVs for a 5-year survival outcome, and RPD has significantly lower cost providing the better cost:benefit ratio. PMID:18053267

Balevi, Ben; Shepperd, Sasha

2007-01-01

139

Revisiting Triple Antibiotic Irrigation of Breast Implant Pockets: A Placebo-controlled Single Practice Cohort Study  

PubMed Central

Background: Capsular contracture is the most common complication following primary augmentation mammoplasty. It remains poorly understood but is attributed to subclinical infection, immunologic response to breast implants, and chronic inflammatory changes caused by the presence of the implants. The infectious theory of contracture has lead to the practice of irrigating implant pockets with a triple antibiotic solution. The purpose of this study was to determine if antibiotic irrigation reduced the incidence and severity of capsular contracture compared with saline irrigation. Methods: A cohort study enrolling all patients having undergone primary augmentation mammoplasty performed by surgeon A and surgeon B between 2011 and 2012 for all women satisfying inclusion and exclusion criteria was conducted. The only difference in surgical technique was the use of antibiotic irrigation by surgeon B. A chi-square test and analysis of variance with predetermined 95% confidence intervals were performed. Results: Fifty-five patients were operated on. Twenty-eight of surgeon A’s patients were included, ranging in age from 22 to 50 with a mean follow-up time of 1.8 years. Twenty-seven of surgeon B’s patients were included, ranging in age from 22 to 56 with a mean follow-up time of 1.6 years. Rate of capsular contracture was 3.6% (surgeon A) and 3.7% (surgeon B). Chi-square statistic was found to be 0.0014 (P = 0.97) and analysis of variance F value was 1 (P = 0.39). Conclusions: Triple antibiotic breast irrigation is not associated with a significant reduction in the incidence or severity of capsular contracture compared with sterile saline when high-quality surgical technique is used. PMID:25289250

Bergman, Ronald S.; Folkers, Bryan L.; Kortes, Matthew J.

2013-01-01

140

Dental implant changes following incineration  

Microsoft Academic Search

Non-visual identification of victims utilizes DNA, fingerprint and dental comparison as primary scientific identifiers. In incidents where a victim has been incinerated, there may be loss of fingerprint detail and denaturing of DNA. Although extremely durable, tooth loss will also occur with extreme temperatures and the characteristics of recovered dental implants, if any, may be the only physical identifying data

J. Berketa; H. James; V. Marino

2011-01-01

141

Technical note: gold marker implants and high-frequency jet ventilation for stereotactic, single-dose irradiation of liver tumors.  

PubMed

With reference to radiosurgery of the liver, we describe techniques designed to solve the methodological problem of striking targets subject to respiratory motion with the necessary precision. Implanting a gold marker in the vicinity of the liver tumor was the first step in ensuring the reproducibility of the isocenter's position. An 18-karat gold rod measuring 1.9 x 3 mm was implanted approximately 2 cm from the edge of the tumor as this was displayed in the spiral, thin-slice CT with contrast media. Both the implantation of the marker and the required, CT-controlled biopsy of the liver tumor can be achieved simultaneously with the same puncture needle. The efficiency of high-frequency jet ventilation (HFJV) in neutralizing the targeted organ's respiratory motion during stereotactic single-dose irradiation was evaluated. The procedure was carried out on ten patients without any complications. In the time between treatment planning and irradiation (3 days), no significant marker migration was observable. In all cases, the gold marker (volume: 7.5 mm(3)) was readily observable in the treatment beam using portal imaging. HFJV provided reliable immobilization. The liver motion in each anesthetized patient was limited to under 3.0 mm in all directions. Thus, the correct field settings and target reproducibility were able to be analyzed and documented during the irradiation. The combination of marker and HFJV enables the determination of stereotactic coordinates directly related to the liver itself and, in this way, stereotactic radiation treatment of liver tumors is freed from the uncertainties involved in orientation to bony landmarks, in respiratory motion, and in changes of position in the stereotactic body frame. The method is feasible and can improve the accuracy of stereotactic body radiation therapy. PMID:16417397

Fritz, P; Kraus, H-J; Dölken, W; Mühlnickel, W; Müller-Nolte, F; Hering, W

2006-02-01

142

Autogenous wisdom tooth transplantation: A case series with 6-9 months follow-up  

PubMed Central

Tooth transplantation can be considered a valid and predictable treatment option for rehabilitating young patients with permanent teeth loss. This study presents several cases of successful autogenous tooth transplantation with a 6-9 months follow-up. Tooth auto-transplantation can be considered a reasonable option for replacing missing teeth when a donor tooth is available. The auto-transplantation of a right mandibular third molar with compromised function and esthetics to replace the residual roots resulting from coronal destruction due to extensive carious lesion of the second molar in the same quadrant as shown in the presented cases can result a viable treatment alternative especially in a young patient that cannot undergo dental implant therapy. Transplantation of mature third molar seems to be a promising method for replacing a lost permanent molar tooth and restoring esthetics and function. This clinical procedure showed excellent functional and esthetical long-term results in the analyzed cases.

Nim?enko, Tatjana; Omerca, Gražvydas; Bramanti, Ennio; Cervino, Gabriele; Laino, Luigi; Cicciù, Marco

2014-01-01

143

Observations on healing of human tooth extraction sockets implanted with bioabsorbable polylactic-polyglycolic acids (PLGA) copolymer root replicas: a clinical, radiographic, and histologic follow-up report of 8 cases  

Microsoft Academic Search

Objective. The objective was to conduct a clinical, radiographic, and histologic follow-up of alveolar socket healing in 8 human cases in which the extraction sockets of the involved teeth were treated with biodegradable root replicas before metallic implants were placed. Study design. Chair side prepared solid and porous forms of root replicas made out of polylactic-polyglycolic acids (PLGA) copolymer were

P. N. Ramachandran Nair; Jens Schug

2004-01-01

144

Anatomically Shaped Tooth and Periodontal Regeneration by Cell Homing  

Microsoft Academic Search

Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-?-caprolactone and hydroxyapatite with 200-µm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular

K. Kim; C. H. Lee; B. K. Kim; J. J. Mao

2010-01-01

145

Pathologic tooth migration.  

PubMed

Pathologic tooth migration (PTM) is a common complication of moderate to severe periodontitis and is often the motivation for patients to seek periodontal therapy. In this review of the literature, available information concerning prevalence, etiology, treatment, and prevention of pathologic tooth migration is summarized. Prevalence of PTM among periodontal patients has been reported to range from 30.03% to 55.8%. A survey of the literature regarding chief complaints of periodontal patients support these high prevalence findings. The etiology of PTM appears to be multifactorial. Periodontal bone loss appears to be a major factor in the etiology of PTM. Many aspects of occlusion can contribute to abnormal migration of teeth, and more than one of those factors may be present in an individual patient. Soft tissue forces of the tongue, cheeks, and lips are known to cause tooth movement and in some situations can cause PTM. Also considered important in the etiology of PTM is pressure produced from inflammatory tissues within periodontal pockets. Because extrusion is a common form of PTM, clinical observations support the theory that eruption forces sometimes play a role in the etiology of PTM. Many oral habits have been associated with PTM which are often difficult for the therapist to detect. Most cases of severe PTM require a team approach to achieve success. Periodontal, orthodontic, and prosthodontic treatment are often required. Many patient variables enter into the selection of treatment for PTM. In early stages of PTM, spontaneous correction of migrated teeth sometimes occurs after periodontal therapy. Light intrusive forces are used successfully to treat extrusion and flaring forms of PTM. Based on the literature reviewed, it appears that many cases of PTM could be prevented through the early diagnosis and treatment of periodontal disease, occlusal contributing factors, gingival enlargement, and oral habits. PMID:15948679

Brunsvold, Michael A

2005-06-01

146

Single-agent and combination-drug regional chemotherapy for head and neck cancer using an implantable infusion pump.  

PubMed

Chemotherapy delivered through angiographically placed catheters requires patient hospitalization, and is usually limited to short-term infusions. Treatment given through surgically placed catheters with external portable infusion pumps permits greater patient freedom and longer infusion durations. However, some patient restrictions remain, and thrombotic or infectious complications are common with long-term therapy. A totally implantable pump has allowed long-term intraarterial therapy in an outpatient population. Patient activity was unrestricted, and the complication rate has been low. This system has been used to deliver single-agent therapy with FUdR, dichloromethotrexate or bleomycin, and combination-drug treatment with cisplatin + FUdR or bleomycin + mitomycin C + dichloromethotrexate. The majority of patients have responded to at least one drug program. Seven of 14 patients who had pumps implanted over 1 year ago have received therapy for at least 1 year, and four patients have had functioning system for over 2 years. Systemic toxicity (except for nausea and vomiting with cisplatin) has been uncommon. Further clinical experience with these programs will be necessary to fully establish the objective response rate. However, the Infusaid Pump has proven safe, reliable and has high patient acceptance. PMID:6478392

Wheeler, R H; Baker, S R; Medvec, B R

1984-10-15

147

Investigating Long-Term Effects of Cochlear Implantation in Single-Sided Deafness: A Best Practice Model for Longitudinal Assessment of Spatial Hearing Abilities and Tinnitus Handicap  

PubMed Central

Objectives To evaluate methods for measuring long-term benefits of cochlear implantation in a patient with single-sided deafness (SSD) with respect to spatial hearing and to document improved quality of life due to reduced tinnitus. Patient A single adult male with profound right-sided sensorineural hearing loss and normal hearing in the left ear who underwent right-sided cochlear implantation. Methods The subject was evaluated at 6, 9, 12, and 18 months after implantation on speech intelligibility with specific target-masker configurations, sound localization accuracy, audiological performance, and tinnitus handicap. Testing conditions involved the acoustic (NH) ear only, the cochlear implant (CI) ear (acoustic ear plugged), and the bilateral condition (CI+NH). Measures of spatial hearing included speech intelligibility improvement due to spatial release from masking (SRM) and sound localization. In addition, traditional measures known as “head shadow,” “binaural squelch” and “binaural summation,” were evaluated. Results The best indicator for improved speech intelligibility was SRM, in which both ears are activated but the relative locations of target and masker(s) are manipulated. Measures that compare performance with a single ear to performance utilizing bilateral auditory input indicated evidence of the ability to integrate inputs across the ears, possibly reflecting early binaural processing, with 12 months of bilateral input. Sound localization accuracy improved with addition of the implant, and a large improvement with respect to tinnitus handicap was observed. Conclusions Cochlear implantation resulted in improved sound localization accuracy when compared to performance utilizing only the NH ear, and reduced tinnitus handicap was observed with use of the implant. The use of SRM addresses some of the current limitations of traditional measures of spatial and binaural hearing, as spatial cues related to target and maskers are manipulated, rather than the ear(s) tested. Sound testing methods and calculations described here are therefore recommended for assessing performance of a larger sample size of individuals with SSD who receive a CI. PMID:25158615

Gartrell, Brian C.; Jones, Heath G.; Kan, Alan; Buhr-Lawler, Melanie; Gubbels, Samuel P.; Litovsky, Ruth Y.

2015-01-01

148

Treatment of Necrotic Calcified Tooth Using Intentional Replantation Procedure  

PubMed Central

Introduction. If the teeth are impacted by a chronic irritant, the pulp space possibly will undergo calcific changes that may impede access opening during root canal treatment. In such cases that conventional endodontic treatment is impossible or impractical, intentional replantation may be considered as a last solution to preserve the tooth. Methods. After failing to perform conventional root canal therapy for a necrotic calcified right mandibular second premolar, the tooth was gently extracted. The root apex was resected and the root end cavity was prepared and filled with calcium enriched mixture (CEM) cement. Then, the extracted tooth was replanted in its original position. Results. After a year the tooth was asymptomatic, and the size of periapical radiolucency was remarkably reduced and no clinical sign of ankylosis was observed. Conclusion. Intentional replantation of the necrotic calcified teeth could be considered as an alternative to teeth extraction, especially for the single-rooted teeth and when nonsurgical and surgical endodontic procedures seem impossible. PMID:24716000

Arvin, Armita; Darvish, Alireza; Aflaki, Sareh

2014-01-01

149

Peri-implant esthetics assessment and management  

PubMed Central

Providing an esthetic restoration in the anterior region of the mouth has been the basis of peri-implant esthetics. To achieve optimal esthetics, in implant supported restorations, various patient and tooth related factors have to be taken into consideration. Peri-implant plastic surgery has been adopted to improve the soft tissue and hard tissue profiles, during and after implant placement. The various factors and the procedures related to enhancement of peri-implant esthetics have been discussed in this review article. PMID:23878557

Balasubramaniam, Aarthi S.; Raja, Sunitha V.; Thomas, Libby John

2013-01-01

150

Comparative stress analysis of delayed and immediate loading of a single implant in an edentulous maxilla model  

PubMed Central

Stress distribution in peri-implant bone in an edentulous maxilla following delayed and immediate loading implant and the effect of implant length on the maximum stress were evaluated by using two kinds of finite element analyses. A threaded implant was loaded with a 100 N vertical force, either immediately or delayed, and examined by finite element analysis with a simple contact relation or a bonding interaction between the implant and the bone, respectively. Higher stresses were observed in cortical bone around the implant neck following delayed loading and in the trabecular bone around the implant threading in the immediate loading model. The maximum stress in the immediate loading model was dramatically higher than in delayed loading. Increased implant length caused decrease in bone stresses in both loading models. Though the stress level was higher, the decrease in the maximum trabecular bone stress in immediate loading was profound. PMID:25342982

Gao, Jie; Esaki, Daisuke; Matsuzaki, Tatsuya; Koyano, Kiyoshi

2014-01-01

151

Treating sensitivity during tooth whitening.  

PubMed

The most common side effect of tooth whitening is tooth sensitivity. There are a number of materials and techniques for reducing sensitivity. This article focuses on potassium nitrate applied either by brushing before initiating whitening or by application via a tray during whitening to reduce sensitivity. A detailed step-by-step procedure for managing hypersensitive patients is described. PMID:17039676

Haywood, Van B

2005-09-01

152

Classification of maxillary tooth transpositions  

Microsoft Academic Search

Tooth transposition is a severe disturbance of tooth order and eruptive position, involving certain teeth, that may occur at any of several specific sites in the mouth. Published cases of transposition involving maxillary teeth were gathered from worldwide sources to study, identify, and classify these occurrences of orthodontic interest. With a sample of 201 cases and on the basis of

Sheldon Peck; Leena Peck

1995-01-01

153

Investigation of an implantable dosimeter for single-point water equivalent path length verification in proton therapy  

SciTech Connect

Purpose: In vivo range verification in proton therapy is highly desirable. A recent study suggested that it was feasible to use point dose measurement for in vivo beam range verification in proton therapy, provided that the spread-out Bragg peak dose distribution is delivered in a different and rather unconventional manner. In this work, the authors investigate the possibility of using a commercial implantable dosimeter with wireless reading for this particular application. Methods: The traditional proton treatment technique delivers all the Bragg peaks required for a SOBP field in a single sequence, producing a constant dose plateau across the target volume. As a result, a point dose measurement anywhere in the target volume will produce the same value, thus providing no information regarding the water equivalent path length to the point of measurement. However, the same constant dose distribution can be achieved by splitting the field into a complementary pair of subfields, producing two oppositely ''sloped'' depth-dose distributions, respectively. The ratio between the two distributions can be a sensitive function of depth and measuring this ratio at a point inside the target volume can provide the water equivalent path length to the dosimeter location. Two types of field splits were used in the experiment, one achieved by the technique of beam current modulation and the other by manipulating the location and width of the beam pulse relative to the range modulator track. Eight MOSFET-based implantable dosimeters at four different depths in a water tank were used to measure the dose ratios for these field pairs. A method was developed to correct the effect of the well-known LET dependence of the MOSFET detectors on the depth-dose distributions using the columnar recombination model. The LET-corrected dose ratios were used to derive the water equivalent path lengths to the dosimeter locations to be compared to physical measurements. Results: The implantable dosimeters measured the dose ratios with a reasonable relative uncertainty of 1%-3% at all depths, except when the ratio itself becomes very small. In total, 55% of the individual measurements reproduced the water equivalent path lengths to the dosimeters within 1 mm. For three dosimeters, the difference was consistently less than 1 mm. Half of the standard deviations over the repeated measurements were equal or less than 1 mm. Conclusions: With a single fitting parameter, the LET-correction method worked remarkably well for the MOSFET detectors. The overall results were very encouraging for a potential method of in vivo beam range verification with millimeter accuracy. This is sufficient accuracy to expand range of clinical applications in which the authors could use the distal fall off of the proton depth dose for tight margins.

Lu, Hsiao-Ming; Mann, Greg; Cascio, Ethan [Francis H. Burr Proton Therapy Center, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Sicel Technologies, Inc., Morrisville, North Carolina 27560 (United States); Francis H. Burr Proton Therapy Center, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

2010-11-15

154

Aesthetical reconstruction of an anterior tooth in an alveolar cleft site:A case report and 3-year follow-up findings.  

PubMed

Abstract An alveolar cleft often displays the furrowed shape of the buccal site because of the lack of alveolar bone and gingival contracts. A 35-year-old woman presented with a repaired cleft lip and a non-grafted alveolar cleft associated with a missing lateral incisor on the left side of the maxilla. The central incisor had been an abutment tooth of a bridge for 15 years; however, it fractured and was extracted. Orthodontic treatment was antecedent to implant reconstruction because the edentulous space was not adequate for a single tooth replacement. As the palate was closed by the mucosa, bone grafting was not performed at the cleft site beforehand. Dental implant placement was performed within the narrowed, beamlike bone, and hydroxyapatite particles were used to augment the ridge. A relaxing incision and expansion of the invaginated mucosa improved the buccal shape of the gum. The usage of a narrow-type implant and bone substitutes facilitated the minimization of surgical stress, even though she did not undergo autologous bone-grafting surgery. Additionally, the aesthetical reconstruction of the anterior region significantly improved her quality of life at the 3-year follow-up. PMID:24773149

Nakata, Hidemi; Kuroda, Shinji; Tachikawa, Noriko; Nagayama, Tomoko; Kasugai, Shohei

2014-04-28

155

Reinforced composite restoration following trauma to a mandibular tooth: technique and follow-up treatment.  

PubMed

The loss of an entire tooth in the anterior region is accompanied by impairment of esthetics, function, phonetics, and self-esteem. It is common knowledge that treatment with implants during childhood or early adolescence is not an option. Splinting of adjacent teeth during growth and development may interfere with the independent process of teeth realignment and repositioning during that phase of life. Other creative solutions must be offered, such as free-standing composite buildup restorations on compromised broken teeth or single wing/cantilevered restorations adhered to one neighboring tooth during the growth period. The positive effects of reinforced composite materials were researched and presented in the literature. Their use is clearly indicated for interim and economical restorations. Long-term follow-up on a mandibular incisor that experienced trauma, losing its clinical crown and vitality when the patient was 12 years of age, is discussed with all the various aspects of material selection, future considerations, and long-term follow-up to adulthood, when a conventional crown was prepared and delivered. PMID:23041989

Smidt, Ami; Sharon, Eldad; Adler, Mordekhai Lipovetsky

2012-10-01

156

WNT10A variants are associated with non-syndromic tooth agenesis in the general population.  

PubMed

Tooth agenesis is the most common developmental dental anomaly. Absence of one or two permanent teeth is found in the majority of affected subjects. Very few patients suffer severe tooth agenesis. Recent studies revealed that WNT10A gene mutations caused syndromic and isolated severe tooth agenesis. In this study, to determine the contribution of WNT10A variants in different severities of tooth agenesis, we investigated the association between WNT10A variants and non-syndromic tooth agenesis in a Chinese population consisting of 505 tooth agenesis patients and 451 normal controls. Twenty-three novel non-synonymous variants were identified. WNT10A variants were detected in 15.8 % (75/474) of patients with 1-3 missing teeth and 51.6 % (16/31) of patients with 4 or more missing teeth. As compared with a frequency of 3.1 % in individuals with full dentition, variant allele frequencies were significantly elevated in both groups with tooth agenesis (p values of 1.00 × 10(-6) and 3.89 × 10(-23), respectively). Our findings showed that WNT10A variants were associated with non-syndromic tooth agenesis from mild to severe tooth agenesis, and the more severe tooth agenesis, the stronger association. Biallelic genotypes of WNT10A variants may have a pathogenic effect on tooth development. Presence of a single variant allele would be predisposing for causation with low penetrance. Together with WNT10A variant, there should be other genetic or environmental factors leading to biallelic variant-related variable clinical manifestations and single allele variant-related low penetrance. The frequent missing tooth positions in the WNT10A-related cases were consistent with that in the general population, suggesting WNT10A plays a critically important role in the etiology of general tooth agenesis. PMID:24043634

Song, Shujuan; Zhao, Ruiying; He, Huiying; Zhang, Jin; Feng, Hailan; Lin, Liyun

2014-01-01

157

Methods for implantation of micro-wire bundles and optimization of single/multi-unit recordings from human mesial temporal lobe  

NASA Astrophysics Data System (ADS)

Objective. The authors report methods developed for the implantation of micro-wire bundles into mesial temporal lobe structures and subsequent single neuron recording in epileptic patients undergoing in-patient diagnostic monitoring. This is done with the intention of lowering the perceived barriers to routine single neuron recording from deep brain structures in the clinical setting. Approach. Over a 15 month period, 11 patients were implanted with platinum micro-wire bundles into mesial temporal structures. Protocols were developed for (A) monitoring electrode integrity through impedance testing, (B) ensuring continuous 24-7 recording, (C) localizing micro-wire position and ‘splay’ pattern and (D) monitoring grounding and referencing to maintain the quality of recordings. Main results. Five common modes of failure were identified: (1) broken micro-wires from acute tensile force, (2) broken micro-wires from cyclic fatigue at stress points, (3) poor in vivo micro-electrode separation, (4) motion artifact and (5) deteriorating ground connection and subsequent drop in common mode noise rejection. Single neurons have been observed up to 14 days post-implantation and on 40% of micro-wires. Significance. Long-term success requires detailed review of each implant by both the clinical and research teams to identify failure modes, and appropriate refinement of techniques while moving forward. This approach leads to reliable unit recordings without prolonging operative times, which will help increase the availability and clinical viability of human single neuron data.

Misra, A.; Burke, J. F.; Ramayya, A. G.; Jacobs, J.; Sperling, M. R.; Moxon, K. A.; Kahana, M. J.; Evans, J. J.; Sharan, A. D.

2014-04-01

158

Dental Implant Systems  

PubMed Central

Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

2010-01-01

159

Occlusion on oral implants: current clinical guidelines.  

PubMed

Proper implant occlusion is essential for adequate oral function and the prevention of adverse consequences, such as implant overloading. Dental implants are thought to be more prone to occlusal overloading than natural teeth because of the loss of the periodontal ligament, which provides shock absorption and periodontal mechanoreceptors, which provide tactile sensitivity and proprioceptive motion feedback. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Thus, we performed a narrative literature review to ascertain the influence of implant occlusion on the occurrence of complications of implant treatment and discuss the clinical considerations focused on the overloading factors at present. The search terms were 'dental implant', 'dental implantation', 'dental occlusion' and 'dental prosthesis'. The inclusion criteria were literature published in English up to September 2013. Randomised controlled trials (RCTs), prospective cohort studies and case-control studies with at least 20 cases and 12 months follow-up interval were included. Based on the selected literature, this review explores factors related to the implant prosthesis (cantilever, crown/implant ratio, premature contact, occlusal scheme, implant-abutment connection, splinting implants and tooth-implant connection) and other considerations, such as the number, diameter, length and angulation of implants. Over 700 abstracts were reviewed, from which more than 30 manuscripts were included. We found insufficient evidence to establish firm clinical guidelines for implant occlusion. To discuss the ideal occlusion for implants, further well-designed RCTs are required in the future. PMID:25284468

Koyano, K; Esaki, D

2015-02-01

160

Partial tooth gear bearings  

NASA Technical Reports Server (NTRS)

A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

Vranish, John M. (Inventor)

2010-01-01

161

Key Systemic and Environmental Risk Factors for Implant Failure.  

PubMed

Dental implants are an important treatment option for patients interested in replacing lost or missing teeth. Although a robust body of literature has reviewed risk factors for tooth loss, the evidence for risk factors associated with dental implants is less well defined. This article focuses on key systemic risk factors relating to dental implant failure, as well as on perimucositis and peri-implantitis. PMID:25434557

Dawson, Dolphus R; Jasper, Samuel

2015-01-01

162

Prosthodontic considerations in the implant-supported all-ceramic restoration of congenitally missing maxillary lateral incisor: a clinical report.  

PubMed

The congenitally missing maxillary lateral incisor is the most common agenesis in the anterior region. There are several treatment options for this anomaly, which causes severe deficiencies: orthodontic space closure, tooth-supported restoration, or single-tooth implant. Each of these solutions has a high degree of success if used in the correct situation. An implant-supported restoration with an interdisciplinary approach provides a predictable outcome. This article describes the treatment of a patient with agenesis of the maxillary left lateral incisor. After orthodontic space management, it was decided to restore the tooth with an all-ceramic crown cemented on a zirconia custom abutment, which fractured after only 6 weeks of service. Fractographic analysis revealed that the failure was due to over-reduction of the buccal wall to correct the labial emergence of the implant. Zirconia abutments should be designed with even wall thicknesses of at least 0.8 mm to avoid areas that may compromise functional success. PMID:24118630

Martínez-Rus, Francisco; Rivera, Begoña; Özcan, Mutlu; Pradíes, Guillermo

2014-04-01

163

Osseointegration of zirconia implants: an SEM observation of the bone-implant interface  

Microsoft Academic Search

BACKGROUND: The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified

Rita Depprich; Holger Zipprich; Michelle Ommerborn; Eduardo Mahn; Lydia Lammers; Jörg Handschel; Christian Naujoks; Hans-Peter Wiesmann; Norbert R Kübler; Ulrich Meyer

2008-01-01

164

Decoronation for the management of an ankylosed young permanent tooth.  

PubMed

Replacement resorption rate is a variable process, and is dependent on age, basal metabolic rate, extra-alveolar time, treatment prior to replantation, amount of root dentin, severity of trauma, and extent of periodontal ligament necrosis. In patients 7-16 years old a tooth is lost 3-7 years after the onset of root resorption. The complications that may develop as a consequence of ankylosis of a permanent incisor in children are due to the inevitable early loss of the traumatized tooth and local arrest of alveolar bone development. An ankylosed tooth should be removed before the changes become so pronounced that they compromise future prosthetic treatment. The treatment options may involve: interceptive regenerative treatment, early extraction of the ankylosed tooth, orthodontic space closure, intentional replantation, extraction of the ankylosed tooth followed with immediate ridge augmentation/preservation, auto-transplantation, single tooth dento-osseous osteotomy, and decoronation. The purpose of this article was to review the considerations involved in the decision-making concerning the use of the decoronation technique for the treatment of a permanent incisor diagnosed as ankylosed. PMID:18173685

Sapir, Shabtai; Shapira, Joseph

2008-02-01

165

Cross-sectional transmission electron microscopy method and studies of implant damage in single crystal diamond  

E-print Network

. INTRODUCTION There has been a growing interest in utilizing synthetic diamond for engineering applications crystal diamond D. P. Hickey,a E. Kuryliw, K. Siebein, and K. S. Jones Materials Science and Engineering microscopy TEM studies of single crystal diamond have been reported, most likely due to the time

Florida, University of

166

Detecting gear tooth fracture in a high contact ratio face gear mesh  

NASA Technical Reports Server (NTRS)

This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect gear tooth fracture in a high contact ratio face gear mesh. The NASA spiral bevel gear fatigue test rig was used to produce unseeded fault, natural failures of four face gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face gears, vibration signals were monitored and recorded for gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the gear tooth fractures in three out of the four fatigue tests, along with gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face gear mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.

Zakrajsek, James J.; Handschuh, Robert F.; Lewicki, David G.; Decker, Harry J.

1995-01-01

167

Broken or knocked out tooth  

MedlinePLUS

Pfenninger JL, Fowlder GC. Management of dental injuries and reimplantation of an avulsed tooth. In: Pfenninger JL, Fowlder GC, eds. Pfenninger & Fowler's Procedures for Primary Care . 3rd ed. Philadelphia, Pa: ...

168

CARABOOSE THE TOOTH FAIRY MOOSE  

E-print Network

, from basic to more advanced, both for the primary and secondary dentitions. The underlying preventive periodontal diseases, dental trauma, anomalous tooth formation and erup- tion come thereafter, which are all

Cai, Long

169

Prosthetic Failure in Implant Dentistry.  

PubMed

Although osseointegrated dental implants have become a predictable and effective modality for the treatment of single or multiple missing teeth, their use is associated with clinical complications. Such complications can be biologic, technical, mechanical, or esthetic and may compromise implant outcomes to various degrees. This article presents prosthetic complications accompanied with implant-supported single and partial fixed dental prostheses. PMID:25434566

Sadid-Zadeh, Ramtin; Kutkut, Ahmad; Kim, Hyeongil

2015-01-01

170

Investigation of an implantable dosimeter for single-point water equivalent path length verification in proton therapy  

PubMed Central

Purpose:In vivo range verification in proton therapy is highly desirable. A recent study suggested that it was feasible to use point dose measurement for in vivo beam range verification in proton therapy, provided that the spread-out Bragg peak dose distribution is delivered in a different and rather unconventional manner. In this work, the authors investigate the possibility of using a commercial implantable dosimeter with wireless reading for this particular application. Methods: The traditional proton treatment technique delivers all the Bragg peaks required for a SOBP field in a single sequence, producing a constant dose plateau across the target volume. As a result, a point dose measurement anywhere in the target volume will produce the same value, thus providing no information regarding the water equivalent path length to the point of measurement. However, the same constant dose distribution can be achieved by splitting the field into a complementary pair of subfields, producing two oppositely “sloped” depth-dose distributions, respectively. The ratio between the two distributions can be a sensitive function of depth and measuring this ratio at a point inside the target volume can provide the water equivalent path length to the dosimeter location. Two types of field splits were used in the experiment, one achieved by the technique of beam current modulation and the other by manipulating the location and width of the beam pulse relative to the range modulator track. Eight MOSFET-based implantable dosimeters at four different depths in a water tank were used to measure the dose ratios for these field pairs. A method was developed to correct the effect of the well-known LET dependence of the MOSFET detectors on the depth-dose distributions using the columnar recombination model. The LET-corrected dose ratios were used to derive the water equivalent path lengths to the dosimeter locations to be compared to physical measurements. Results: The implantable dosimeters measured the dose ratios with a reasonable relative uncertainty of 1%–3% at all depths, except when the ratio itself becomes very small. In total, 55% of the individual measurements reproduced the water equivalent path lengths to the dosimeters within 1 mm. For three dosimeters, the difference was consistently less than 1 mm. Half of the standard deviations over the repeated measurements were equal or less than 1 mm. Conclusions: With a single fitting parameter, the LET-correction method worked remarkably well for the MOSFET detectors. The overall results were very encouraging for a potential method of in vivo beam range verification with millimeter accuracy. This is sufficient accuracy to expand range of clinical applications in which the authors could use the distal fall off of the proton depth dose for tight margins. PMID:21158298

Lu, Hsiao-Ming; Mann, Greg; Cascio, Ethan

2010-01-01

171

Biomechanical and histomorphometric comparison between zirconia implants with varying surface textures and a titanium implant in the maxilla of miniature pigs  

Microsoft Academic Search

Background: Mechanical properties and biocompatibility make zirconia ceramics suitable implant material. The characteristics of tooth-color like, the ability to be machined and the low plaque affinity make zirconia especially suitable as a dental implant material. The influence of surface modification on the osseointegration of this material has not been extensively investigated. Purpose: Long-term investigations with titanium implants have shown superior

M. Gahlert; T. Gudehus; S. Eichhorn; E. Steinhauser; H. Kniha; W. Erhardt

2007-01-01

172

Cochlear Implants  

MedlinePLUS

... FDA) website on cochlear implants. Cochlear implants are electronic hearing devices. Doctors implant cochlear implants into people ... State & Local Officials Consumers Health Professionals Science & Research Industry Scroll back to top

173

Immediate, non-submerged, root-analogue direct laser metal sintering (DLMS) implants: a 1-year prospective study on 15 patients.  

PubMed

This study evaluated the 1-year survival and success rate of root-analogue direct laser metal sintering (DLMS) implants, placed into the extraction sockets of 15 patients. DLMS is a technology which allows solids with complex geometry to be fabricated by annealing metal powder microparticles in a focused laser beam, according to a computer-generated three-dimensional (3D) model; the fabrication process involves the laser-induced fusion of titanium microparticles, in order to build, layer-by-layer, the desired object. Cone-beam computed tomography (CBCT) acquisition and 3D image conversion, combined with the DLMS process, allow the fabrication of custom-made, root-analogue implants (RAIs). CBCT images of 15 non-restorable premolars (eight maxilla; seven mandible) were acquired and transformed into 3D models: from these, custom-made, root-analogue DLMS implants with integral abutment were fabricated. Immediately after tooth extraction, the RAIs were placed in the sockets and restored with a single crown. One year after implant placement, clinical and radiographic parameters were assessed: success criteria included absence of pain, suppuration, and exudation; absence of implant mobility and absence of continuous peri-implant radiolucency; distance between the implant shoulder and the first visible bone-to-implant contact <1.5 mm from initial surgery; and absence of prosthetic complications. At the 1-year follow-up, no implants were lost, for a survival rate of 100 %. All implants were stable, with no signs of infection. The good conditions of the peri-implant tissues were confirmed by the radiographic examination, with a mean DIB of 0.7 mm (±0.2). The possibility of fabricating custom-made, RAI DLMS implants opens new interesting horizons for immediate placement of dental implants. PMID:23494103

Mangano, Francesco Guido; De Franco, Michele; Caprioglio, Alberto; Macchi, Aldo; Piattelli, Adriano; Mangano, Carlo

2014-07-01

174

Clinical Management of Implant Prostheses in Patients with Bruxism  

PubMed Central

There is general agreement that excessive stress to the bone-implant interface may result in implant overload and failure. Early failure of the implant due to excessive loading occurs shortly after uncovering the implant. Excess load on a final restoration after successful implant integration can result in physical failure of the implant structure. Many clinicians believe that overload of dental implants is a risk factor for vertical peri-implant bone loss and/or may be detrimental for the suprastructure in implant prostheses. It has been documented that occlusal parafunction, such as, bruxism (tooth grinding and clenching) affects the outcome of implant prostheses, but there is no evidence for a causal relation between the failures and overload of dental implants. In spite of this lack of evidence, often metal restorations are preferred instead of porcelain for patients in whom bruxism is presumed on the basis of tooth wear. The purpose of this paper is to discuss the importance of the occlusal scheme used in implant restorations for implant longevity and to suggest a clinical approach and occlusal materials for implant prostheses in order to prevent complications related to bruxism. PMID:22701484

Komiyama, Osamu; Lobbezoo, Frank; De Laat, Antoon; Iida, Takashi; Kitagawa, Tsuyoshi; Murakami, Hiroshi; Kato, Takao; Kawara, Misao

2012-01-01

175

Interleukin-1? level in peri-implant crevicular fluid and its correlation with the clinical and radiographic parameters  

PubMed Central

Background and Objectives: Assessing only the clinical and radiographic parameters for evaluation of dental implants may not be enough as they often reflect extensive inflammatory changes in the periodontal tissues. As peri-implant crevicular fluid (PICF) can give us a more prompt and objective measure of the disease activity, the purpose of this case series is to assess the peri-implant health status of single tooth dental implants not only clinically and radiographically but also biochemically. Materials and Methods: Thirteen patients were subjected to dental implants at single edentulous sites using a conventional surgical approach. At baseline, 6 months, and 12 months after implant placement, the clinical and radiographic parameters were recorded. Additionally, IL-1? in PICF was estimated using the ELISA kit at 6th and 12th month. Results: The clinical and radiographic parameters differed significantly around the implants at different time intervals with IL-1? levels showing highly significant differences between 6 months (31.79 ± 12.26 pg/?l) and 12 months (113.09 ± 51.11 pg/?l). However, Spearman's correlation coefficient showed no correlation with the clinical and radiographic parameters. Interpretation and Conclusion: Assessment of the various parameters confirmed that all the implants had a healthy peri-implant status. Although the levels of IL-1? in PICF were elevated at the 12th month, they were well within the healthy range as observed by previous studies. This indicates that IL-1?, a biochemical marker, can be used as an adjunct to clinical and radiographic parameters in the assessment of EARLY inflammatory changes around implants. PMID:24872632

Kajale, Aniruddha M.; Mehta, Dhoom S.

2014-01-01

176

[Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses].  

PubMed

An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine oral examinations are the prevention and, when necessary, the treatment of pathological conditions and complications. With regard to prevention, attention should be paid to information and instruction, oral biofilm and calculus, non-functional activities, hard tooth tissues, periodontal and peri-implant tissues, and saliva. Subsequently, it can be determined whether the intended durability and profitability have been achieved or can still be achieved, whether or not through indicated adjustments. Special attention should be paid to endodontically treated teeth. Restorative, repair or replacement treatments may be indicated in case ofcomplications, such as loose single- or multi-unitfixed dental prosthesis, fracture of a fixed dental prosthesis unit, lost tooth pulp vitality, tooth root fracture, and implant or implant abutment problems. PMID:23923444

de Baat, C; van Loveren, C; van der Maarel-Wierink, C D; Witter, D J; Creugers, N H J

2013-01-01

177

The effect of estrogen administration during early pregnancy upon the survival of single implanted pig embryos.  

PubMed

In the present study, we investigated the influence of exogenous estrogen on embryo survival after transfer into prepubertal gilts in which estrus had been induced. In the first experiment, estrus was induced in prepubertal gilts by the administration of 1,000 IU of eCG and 750 IU of hCG every 72 h. Several blastocysts were recovered on d 6 (d 0 is the day of hCG administration), and 1 embryo was transferred to the tip of 1 side of the uterine horn on d 6 (Control). In treated groups, after embryo transfer, 5 mg of estradiol benzoate (EB) was administered on d 11 (EB5mg-1) or d 11, d 13, and d 15 (EB5mg-3) or d 11, 12, 13, 14, and 15 (EB5mg-5) or 20 mg of estradiol dipropionate (EDP) was administered on d 11 (EDP20mg-1) or d 11 and d 14 (EDP20mg-2). Autopsy examinations were performed on d 53 to 60. Although nontreated gilts did not become pregnant, gilts in each of the estradiol-treated groups became pregnant. The greatest pregnancy rate (77.8%, 7/9) was obtained with EDP20mg-2 (EDP20mg-2 > control: P < 0.05). In a second experiment, 1 blastocyst was transferred to prepubertal gilts and treated with EDP20mg-2. Pregnancy in recipient pigs was confirmed by ultrasonography, and pigs were allowed to farrow. Embryo survival rate was high on d 30 of pregnancy (75%, 9/12) but had a tendency (P = 0.0995) to decline from d 30 to delivery (33.3%, 4/12). In a third experiment, prepubertal gilts were administered 5 mg of EDP on d 11 (EDB5mg-1) and d 11 and d 14 (EDP5mg-2). Autopsy examinations were performed on d 53 to 58. Pseudopregnancy rate was high for EDP5mg-2 (63.6%, 7/11) compared with EDP5mg-1 (0%, 0/11; P < 0.05). In a fourth experiment, prepubertal gilts were transferred 1 blastocyst and treated with EDP5mg-2. Pregnancy was confirmed in recipient pigs by ultrasonography, and pigs were subsequently allowed to farrow. Embryo survival rate remained unchanged from d 30 of pregnancy to delivery (66.7%; 8/12). One piglet died from dystocia, and 1 suffered from deformity involving double-breasted hooves and died 6 d after birth. There was no difference (P > 0.05) in survival rate on d 30 of pregnancy and weaning (50%, 6/12). Body weight at birth and at weaning did not differ from that reported in previous studies. In conclusion, this study showed that EDP5mg-2 treatment during early pregnancy leads to full-term development of a single embryo. PMID:22829621

Kawarasaki, T; Enya, S; Otsu, Y

2012-12-01

178

Measurements of the diffusion of iron and carbon in single crystal NiAl using ion implantation and secondary ion mass spectrometry  

SciTech Connect

Classical diffusion measurements in intermetallic compounds are often complicated by low diffusivities or low solubilities of the elements of interest. Using secondary ion mass spectrometry for measurements over a relatively shallow spatial range may be used to solve the problem of low diffusivity. In order to simultaneously obtain measurements on important impurity elements with low solubilities, the authors have used ion implantation to supersaturate a narrow layer near the surface. Single crystal NiAl was implanted with either {sup 12}C or both {sup 56}Fe and {sup 12}C in order to investigate the measurement of substitutional (Fe) versus interstitial (C) tracer diffusion and the cross effect of both substitutional and interstitial diffusion. When C alone was implanted negligible diffusion was observed over the range of times and temperatures investigated. When both Fe and C were implanted together significantly enhanced diffusion of the C was observed, which is apparently associated with the movement of Fe. This supports one theory of dynamic strain aging in Fe alloys NiAl.

Hanrahan, R.J. Jr. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Withrow, S.P. [Oak Ridge National Lab., TN (United States). Solid State Div.; Puga-Lambers, M. [Univ. of Florida, Gainesville, FL (United States)

1998-12-31

179

Has tooth structure been replaced?  

PubMed

In my opinion, there is an obvious trend in the dental literature and in continuing education courses to promote overcutting teeth when preparing them for restorations. There are many reasons for overcutting. Some feel that there is a more optimum esthetic potential when the teeth are prepared more deeply, which is a debatable view. Others are using all-ceramic crowns or polymer crowns when other types of less radical crowns could be used. There also is a significant tendency to prepare teeth for crowns instead of for onlays or inlays, thereby removing more tooth structure than is necessary. High-speed dental air rotor or electric handpieces can cause inadvertent removal of more tooth structure than is necessary. Using large burs can overcut tooth structure, and teeth should be reversed. PMID:11811729

Christensen, Gordon J

2002-01-01

180

Influence of directionality and maximal power output on speech understanding with bone anchored hearing implants in single sided deafness.  

PubMed

Bone-anchored hearing implants (BAHI) are routinely used to alleviate the effects of the acoustic head shadow in single-sided sensorineural deafness (SSD). In this study, the influence of the directional microphone setting and the maximum power output of the BAHI sound processor on speech understanding in noise in a laboratory setting were investigated. Eight adult BAHI users with SSD participated in this pilot study. Speech understanding in noise was measured using a new Slovak speech-in-noise test in two different spatial settings, either with noise coming from the front and noise from the side of the BAHI (S90N0) or vice versa (S0N90). In both spatial settings, speech understanding was measured without a BAHI, with a Baha BP100 in omnidirectional mode, with a BP100 in directional mode, with a BP110 power in omnidirectional and with a BP110 power in directional mode. In spatial setting S90N0, speech understanding in noise with either sound processor and in either directional mode was improved by 2.2-2.8 dB (p = 0.004-0.016). In spatial setting S0N90, speech understanding in noise was reduced by either BAHI, but was significantly better by 1.0-1.8 dB, if the directional microphone system was activated (p = 0.046), when compared to the omnidirectional setting. With the limited number of subjects in this study, no statistically significant differences were found between the two sound processors. PMID:23700268

Krempaska, Silvia; Koval, Juraj; Schmid, Christoph; Pfiffner, Flurin; Kurz, Anja; Kompis, Martin

2014-06-01

181

Laser ablation of human tooth  

NASA Astrophysics Data System (ADS)

We report the measurements of ablation threshold of human tooth in air using photo-thermal deflection technique. A third harmonic (355nm) of Nd:YAG (yttrium aluminum garnet) laser was used for irradiation and a low power helium neon laser as a probe beam. The experimental observations of ablation threshold in conjunction with theoretical model based on heat conduction equations for simulating the interaction of a laser radiation with a calcified tissue are used to estimate the absorption coefficient of human tooth.

Franklin, Sushmita R.; Chauhan, P.; Mitra, A.; Thareja, R. K.

2005-05-01

182

Immediate placement of implant in fresh extraction socket with early loading.  

PubMed

Implant placement in maxillary anterior region has most aesthetic challenges in implant dentistry because tooth loss lead to bone resorption and collapse of gingival architecture, which lead to aesthetic compromise and inadequate bone for implant placement. Immediate implant placement into fresh extraction socket reduces the treatment time, cost, preserved the gingival aesthetic and increases the comfort of the patient. This article describes the procedure for immediate implant placement in fresh extraction socket and early loading of implant with zirconia crown. Clinical and radiographic examination revealed width and length of the tooth for selecting implant size and design. Cement retained zirconia crown was used for early loading. Implant was successfully loaded and was functional during 36 months follow up period. Immediate placement and early loading of dental implant provides advantages like fewer surgical procedures, shorter treatment time, and improved aesthetic and psychological confidence. PMID:23230368

Singh, Archana; Gupta, Aratee; Yadav, Ashish; Chaturvedi, T P; Bhatnagar, Atul; Singh, B P

2012-09-01

183

Immediate placement of implant in fresh extraction socket with early loading  

PubMed Central

Implant placement in maxillary anterior region has most aesthetic challenges in implant dentistry because tooth loss lead to bone resorption and collapse of gingival architecture, which lead to aesthetic compromise and inadequate bone for implant placement. Immediate implant placement into fresh extraction socket reduces the treatment time, cost, preserved the gingival aesthetic and increases the comfort of the patient. This article describes the procedure for immediate implant placement in fresh extraction socket and early loading of implant with zirconia crown. Clinical and radiographic examination revealed width and length of the tooth for selecting implant size and design. Cement retained zirconia crown was used for early loading. Implant was successfully loaded and was functional during 36 months follow up period. Immediate placement and early loading of dental implant provides advantages like fewer surgical procedures, shorter treatment time, and improved aesthetic and psychological confidence. PMID:23230368

Singh, Archana; Gupta, Aratee; Yadav, Ashish; Chaturvedi, T. P.; Bhatnagar, Atul; Singh, B. P.

2012-01-01

184

Biology of tooth replacement in amniotes  

PubMed Central

Tooth replacement is a common trait to most vertebrates, including mammals. Mammals, however, have lost the capacity for continuous tooth renewal seen in most other vertebrates, and typically have only 1–2 generations of teeth. Here, we review the mechanisms of tooth replacement in reptiles and mammals, and discuss in detail the current and historical theories on control of timing and pattern of tooth replacement and development. PMID:23788284

Whitlock, John A; Richman, Joy M

2013-01-01

185

A two DOF simulation of meshing in spur gear sets with modelling of the effect of individual tooth mass  

NASA Astrophysics Data System (ADS)

A Two-Degree Of Freedom analytical model of meshing in a single-stage spur gear set was developed and used for time-domain dynamic simulation. Apart from the time-varying tooth stiffness, the individual tooth mass, reduced to the meshing point, was also taken into consideration and modeled. The simulations that were performed by means of MatLab software using numerical methods highlight the effect of the individual tooth mass in the dynamic response of the gear stage.

Komitopoulos, Nikolaos; Vakouftsis, Christos

2014-10-01

186

Axial relationship between dental implants and teeth/implants: a radiographic study.  

PubMed

The relationship of dental implants with neighboring teeth will affect both occlusal relationship and distribution of forces; thus, the purpose of this study was to examine implants' axial relationship with adjacent and opposing teeth/implants. Data of dental implants patients was retrieved. Panoramic X rays were digitized. Computer-based software was used to measure the angular relationship between the implants and adjacent/opposing teeth and implants. Data was further sorted by the mode of placement and implants position. 50 patients (219 implants) were included. Mean angle to adjacent tooth/implant was 178.71° ± 9.18° (range 129.7°-206°). Implants were more parallel to adjacent teeth (180.99° ± 1.06°) than to adjacent implants (176.32° ± 0.54°; P = .0001). Mean angular relationship to opposite tooth was 167.88° ± 8.92° (range 137.7°-179.8°). Implants that were placed freehand or with positional guide had similar intra-arch relationship (178.22° and 178.81°, respectively) and similar inter-arch angulations (164.46° and 167.74°). Molars had greater deviation of the angular relationship (175.54°) compared to premolars (181.62°) and incisors (180.55°, P = .0001). Implants placed in the maxilla had smaller axial deviation compared to implants in the mandible (180.41° ± 0.64 vs 177.14° ± 1.02; P = .0081). Good axial relationship may be obtained in most implants placed by an experienced clinician, even when placed freehand. The mandibular posterior region is more prone to axial deviation and as such requires special attention. PMID:25106006

Machtei, Eli E; Oettinger-Barak, Orit; Horwitz, Jacob

2014-08-01

187

Tooth Avulsion in the School Setting  

ERIC Educational Resources Information Center

Tooth avulsions occur when a tooth is displaced from its socket. Tooth avulsions are common dental injuries that may occur before, during, or after school. Therefore, it is essential that school nurses be well prepared to intervene when such a dental emergency arises. It is also imperative that school nurses and school personnel are fully equipped…

Krause-Parello, Cheryl A.

2005-01-01

188

Rare Periodontal Ligament Drainage for Periapical Inflammation of an Adjacent Tooth: A Case Report and Review of the Literature  

PubMed Central

Aim. To report a case with an unusual drainage route of periapical inflammation exiting through the gingival sulcus of an adjacent vital tooth and review probable factors determining the diversity of the discharge routes of periapical inflammation. Summary. An 18-year-old male patient presented with periodontal abscess of tooth 46, which was found to be caused by a periapical cyst with an acute abscess of tooth 45. During endodontic surgery, a rarely reported drainage route for periapical inflammation via the gingival sulcus of an adjacent vital tooth was observed for the first time. Complete periodontal healing of the deep pocket of tooth 46 and hiding of the periapical cyst of tooth 45 followed after root canal treatment and periapical surgery with Bio-Oss Collagen implantation on tooth 45. The drainage routes of periapical inflammation are multivariate and the diversity of drainage pathways of periapical inflammation is mainly related to factors such as gravity, barriers against inflammation, and the causative tooth itself. PMID:25587462

Guo, Hongmei; Lu, Wei; Han, Qianqian; Li, Shubo; Yang, Pishan

2014-01-01

189

The effects of a systemic single dose of zoledronic acid on post-implantation bone remodelling and inflammation in an ovariectomised rat model.  

PubMed

Bisphosphonates reverse the negative effects of ovariectomy on bone, but they have also been associated with adverse processes in human jawbone. The molecular events determining bone regeneration and implant integration in osteoporotic conditions, with and without bisphosphonate treatment, are unclear. In this study, ovariectomised rats, to which a single dose of saline (NaCl) or zoledronic acid (Zol) was administered, received titanium alloy implants in their tibiae and mandibles. An enzyme-linked immunosorbent assay, gene expression analysis and histomorphometry were performed. The results show that ovariectomy, per se, upregulated the expression of genes denoting bone formation in the tibia, bone remodelling in the mandible and apoptosis in the tibia and mandible. Zoledronic acid administration resulted in lower levels of a remodelling marker in serum and downregulated gene expression for inflammation, bone formation, angiogenesis and apoptosis, mainly in the mandible, after 28 d of healing. Histomorphometry revealed improved bone-to-implant contact in the tibia, while the opposite was observed in the mandible. The present data show that a systemic single dose of zoledronic acid, in ovariectomised animals, results in site-specific differences in the regulation of genes involved in bone healing and regeneration in association with implant installation. These events occur in parallel with site-specific differences in the rate of osseointegration, indicating diverse tissue responses in the tibia and mandible after zoledronic acid treatment. The zoledronic acid effect on gene expression, during the late phase of healing in the mandible, suggests negative effects by the anti-resorptive agent on osseointegration at that particular site. PMID:23182921

Cardemil, Carina; Omar, Omar M; Norlindh, Birgitta; Wexell, Cecilia L; Thomsen, Peter

2013-02-01

190

Diagnosis of cracked tooth syndrome  

PubMed Central

The incidences of cracks in teeth seem to have increased during the past decade. Dental practitioners need to be aware of cracked tooth syndrome (CTS) in order to be successful at diagnosing CTS. Early diagnosis has been linked with successful restorative management and predictably good prognosis. The purpose of this article is to highlight factors that contribute to detecting cracked teeth. PMID:23066261

Mathew, Sebeena; Thangavel, Boopathi; Mathew, Chalakuzhiyil Abraham; Kailasam, SivaKumar; Kumaravadivel, Karthick; Das, Arjun

2012-01-01

191

An automatic and effective tooth isolation method for dental radiographs  

NASA Astrophysics Data System (ADS)

Tooth isolation is a very important step for both computer-aided dental diagnosis and automatic dental identification systems, because it will directly affect the accuracy of feature extraction and, thereby, the final results of both types of systems. This paper presents an effective and fully automatic tooth isolation method for dental X-ray images, which contains up-per-lower jaw separation, single tooth isolation, over-segmentation verification, and under-segmentation detection. The upper-lower jaw separation mechanism is based on a gray-scale integral projection to avoid possible information loss and incorporates with the angle adjustment to handle skewed images. In a single tooth isolation, an adaptive windowing scheme for locating gap valleys is proposed to improve the accuracy. In over-segmentation, an isolation-curve verification scheme is proposed to remove excessive curves; and in under-segmentation, a missing-teeth detection scheme is proposed. The experimental results demonstrate that our method achieves the accuracy rates of 95.63% and 98.71% for the upper and lower jaw images, respectively, from the test database of 60 bitewing dental radiographs, and performs better for images with severe teeth occlusion, excessive dental works, and uneven illumination than that of Nomir and Abdel-Mottaleb's method. The method without upper-lower jaw separation step also works well for panoramic and periapical images.

Lin, P.-L.; Huang, P.-W.; Cho, Y. S.; Kuo, C.-H.

2013-03-01

192

Long-term stability of soft tissues following alveolar ridge preservation: 10-year results of a prospective study around nonsubmerged implants.  

PubMed

The purpose of this study was to evaluate the long-term clinical outcomes around implants placed in sites previously augmented with demineralized bovine bone mineral with 10% collagen (Bio-Oss Collagen, Geistlich). In this prospective study, 36 consecutive, healthy patients, in need of a single-tooth extraction (incisors, canines, and premolars) and implant replacement, were included. After tooth extraction, Bio-Oss Collagen was inserted in the socket and covered either with a double layer of collagen membrane (test) or with a few drops of a flowable polylactide polymer (control). Following a healing period of 4 to 6 months, a single nonsubmerged implant surgery was performed. After cementation of a single ceramic crown, patients were asked to follow an individualized supportive periodontal therapy program. Clinical and radiographic data were obtained after prosthesis delivery (baseline) and at the 10-year follow-up visit. At the 10-year examination, two patients were lost to follow-up. All implants demonstrated healthy peri-implant soft tissues as documented by standard parameters (full-mouth plaque score, full-mouth bleeding score, local bleeding on probing) in both groups. Mean soft tissue recession (REC) was 0.39 ± 0.54 mm for the test group and 0.50 ± 0.33 mm for the control, with no significant difference between the two groups. The results of this prospective study confirmed the long-term stability of the peri-implant marginal soft tissues supported by regenerated bone by means of the described technique using Bio-Oss Collagen. If the patient is properly followed throughout time, the risk for mucosal recession is low, with < 1 mm of mean REC after 10 years. PMID:25411735

Roccuzzo, Mario; Gaudioso, Luigi; Bunino, Marco; Dalmasso, Paola

2014-01-01

193

Totally implantable venous access devices: retrospective analysis of different insertion techniques and predictors of complications in 796 devices implanted in a single institution  

PubMed Central

Background The aim of this study was to assess the efficacy and safety of totally implanted vascular devices (TIVAD) using different techniques of insertion. Methods We performed a retrospective study using a prospective collected database of 796 consecutive oncological patients in which TIVADs were inserted. We focused on early and late complications following different insertion techniques (surgical cutdown, blind and ultrasound guided percutaneous) according to different techniques. Results Ultrasound guided technique was used in 646 cases, cephalic vein cutdown in 102 patients and percutaneous blind technique in 48 patients. The overall complication rate on insertion was 7.2% (57 of 796 cases). Early complications were less frequent using the ultrasound guided technique: arterial puncture (p?=?0.009), technical failure (p?=?0.009), access site change after first attempt (p?=?0.002); pneumothorax occurred in 4 cases, all using the blind percutaneus technique. Late complications occurred in 49 cases (6.1%) which required TIVAD removal in 43 cases and included: sepsis (29 cases), thrombosis (3 cases), dislocation (7 cases), skin dehiscence (3 cases), and severe pain (1 case). Conclusion Ultrasound guided technique is the safest option for TIVAD insertion, with the lowest rates of immediate complications. PMID:24886342

2014-01-01

194

Comparison of Long-term Survival of Implants and Endodontically Treated Teeth  

PubMed Central

The outcomes of both dental implants and endodontically treated teeth have been extensively studied. However, there is still a great controversy over when to keep a natural tooth and when to extract it for a dental implant. This article reviews the benefits and disadvantages of both treatment options and discusses success vs. survival outcomes, as well as the impact of technical advances for modern endodontics and endodontic microsurgery on the long-term prognosis of tooth retention. PMID:24065635

Setzer, F.C.; Kim, S.

2014-01-01

195

How does an error in positioning the template affect the accuracy of implants inserted using a single fixed mucosa-supported stereolithographic surgical guide?  

PubMed

Computer-aided implantology using a single fixed stereolithographic surgical guide involves a sequence of diagnostic and therapeutic events, and errors can creep in at different stages. Taken together, these can be termed the 'total error'. A positioning of the surgical guide on the support surface different to that of the diagnostic template may generate an error that reoccurs with all the implants inserted, and this error can be termed the 'guide positioning error'. The aim of the present study was to measure the deviation between the planned and inserted implants due to this guide positioning error, to evaluate if this error was statistically significant, and concurrently, to assess the influence of the type of arch (upper vs lower jaw) and mucosal thickness on the guide positioning error. Twenty-four subjects were treated and 172 implants inserted. Preoperative and postoperative computed tomography images were compared using Mimics software to determine the total error and guide positioning error. Quantitative data were described; the t-test and Pearson correlation coefficient were used. The guide positioning error was found to affect the accuracy, but was statistically significant only for global coronal deviation (P = 0.038). Arch of support and mucosa thickness did not affect the guide positioning error. PMID:23916310

Cassetta, M; Di Mambro, A; Giansanti, M; Stefanelli, L V; Barbato, E

2014-01-01

196

Immediate implant placement: surgical techniques for prevention and management of complications.  

PubMed

Loss of soft and hard tissue is common after tooth extraction. Substantial resorption of alveolar bone compromises esthetics and may result in prosthetic and surgical limitations. Immediate implant placement at the time of tooth extraction is used to maintain alveolar ridge dimensions. Clinical studies support the successful outcome of immediate placement of dental implants in fresh extraction sockets; comparative clinical studies have found that implant survival rates after immediate placement are similar to those after delayed placement. This article addresses surgical techniques for immediate implant placement and the prevention and the management of complications associated with this procedure. PMID:25434560

Al-Sabbagh, Mohanad; Kutkut, Ahmad

2015-01-01

197

Single electron charging of Sn nanocrystals in thin SiO2 film formed by low energy ion implantation  

Microsoft Academic Search

We report on a simple technique for fabricating a Sn nanocrystal array in thin SiO2 film. This technique uses low energy ion implantation followed by thermal annealing. Isolated Sn nanocrystals 5 nm in diameter are formed in an array with excellent size and position uniformity. Barrier height between a Sn nanocrystal and the substrate was obtained by measuring the temperature

A. Nakajima; T. Futatsugi; N. Horiguchi; H. Nakao; N. Yokoyama

1997-01-01

198

Single-stage implantation in the atrophic alveolar ridge of the mandible with the Norian skeletal repair system  

Microsoft Academic Search

Dental implants have played a part in rehabilitation of the jaws for more than 40 years, but in some cases they alone are inadequate because of extreme alveolar resorption. Correction may necessitate a two-stage procedure with additional interventions. We have made a preliminary study of the use of the Norian skeletal repair system (SRS), a carbonated calcium phosphate bone cement

Frank Hölzle; Florian Bauer; Marco R. Kesting; Thomas Mücke; Herbert Deppe; Klaus-Dietrich Wolff; Sami Swaid

2011-01-01

199

Achieving high-quality single-atom nitrogen doping of graphene/SiC(0001) by ion implantation and subsequent thermal stabilization.  

PubMed

We report a straightforward method to produce high-quality nitrogen-doped graphene on SiC(0001) using direct nitrogen ion implantation and subsequent stabilization at temperatures above 1300 K. We demonstrate that double defects, which comprise two nitrogen defects in a second-nearest-neighbor (meta) configuration, can be formed in a controlled way by adjusting the duration of bombardment. Two types of atomic contrast of single N defects are identified in scanning tunneling microscopy. We attribute the origin of these two contrasts to different tip structures by means of STM simulations. The characteristic dip observed over N defects is explained in terms of the destructive quantum interference. PMID:24884035

Telychko, Mykola; Mutombo, Pingo; Ondrá?ek, Martin; Hapala, Prokop; Bocquet, François C; Koloren?, Jind?ich; Vondrá?ek, Martin; Jelínek, Pavel; Švec, Martin

2014-07-22

200

Aggregatibacter Actinomycetemcomitans – A Tooth Killer?  

PubMed Central

Strong evidence is available on Aggregatibacter actinomycetemcomitans (A.a) on its role as the causative agent of localised juvenile periodontitis (LJP), a disease characterised by rapid destruction of the tooth-supporting tissues. This organism possesses a large number of virulence factors with a wide range of activities which enable it to colonise the oral cavity, invade periodontal tissues, evade host defences, initiate connective tissue destruction and interfere with tissue repair. Adhesion to epithelial and tooth surfaces is dependent on the presence of surface proteins and structures such as microvesicles and fimbriae. Invasion has been demonstrated in vivo and in vitro. The organism has a number of means of evading host defences which include: (i) production of leukotoxin; (ii) producing immunosuppressive factors; (iv) secreting proteases capable of cleaving IgG; and (v) producing Fc-binding. PMID:25302290

Ummer, Fajar; Dhivakar, C.P

2014-01-01

201

Optical spectroscopy and tooth decay  

NASA Astrophysics Data System (ADS)

Optical spectroscopy in the ultraviolet, visible and mid-infrared spectral regions has been used to discriminate between healthy and diseased teeth of patients in the age range 15-75 years. Spectral scans of absorbance versus wavenumber and fluorescence intensity versus wavelength have been recorded and investigated for caries and periodontal disease. Such optical diagnostics can prove very useful in the early detection and treatment of tooth decay.

Misra, P.; De, T.; Singh, R.

2005-11-01

202

Molecular Genetics of Supernumerary Tooth Formation  

PubMed Central

Summary Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/?(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering. PMID:21309064

Wang, Xiu-Ping; Fan, Jiabing

2011-01-01

203

Tooth Size Variation Related to Age in Amboseli Baboons  

PubMed Central

We measured the molar size from a single population of wild baboons from Amboseli (Kenya), both females (n = 57) and males (n = 50). All the females were of known age; the males represented a mix of known-age individuals (n = 31) and individuals with ages estimated to within 2 years (n = 19). The results showed a significant reduction in the mesiodistal length of teeth in both sexes as a function of age. Overall patterns of age-related change in tooth size did not change whether we included or excluded the individuals of estimated age, but patterns of statistical significance changed as a result of changed sample sizes. Our results demonstrate that tooth length is directly related to age due to interproximal wearing caused by M2 and M3 compression loads. Dental studies in primates, including both fossil and extant species, are mostly based on specimens obtained from osteological collections of varying origins, for which the age at death of each individual in the sample is not known. Researchers should take into account the phenomenon of interproximal attrition leading to reduced tooth size when measuring tooth length for ondontometric purposes. PMID:21325862

Galbany, Jordi; Dotras, Laia; Alberts, Susan C.; Pérez-Pérez, Alejandro

2011-01-01

204

Efficacy of intraoperative vancomycin powder use in intrathecal baclofen pump implantation procedures: single institutional series in a high risk population.  

PubMed

We aimed to assess the efficacy of intraoperative vancomycin powder in intrathecal baclofen pump placement patients, a high risk population. A retrospective review was conducted using prospectively collected data at an academic tertiary care unit. The neurosurgical adult patient population was queried for all intrathecal baclofen pump implantation procedures. Patients were then reviewed for the use of intraoperative crystalline vancomycin powder. Those with a history of prior surgical site infection, chronic systemic infections or osteomyelitis were excluded. Anhydrous, crystalline vancomycin was utilized in the wound bed after completion of implantation, distributed evenly in the case of multiple incisions. Patients received 500 mg or 1,000 mg of crystallized vancomycin, evenly distributed through the wound layers based on a 70 kg weight cutoff. Intraoperative institutional standards of infection prophylaxis were unchanged throughout the study period. Infection rate of baclofen pump placement prior to the use of vancomycin powder from 2001-2009 at the same institution was monitored. Wound infection rate was tracked for a 12 month postoperative period. Six patients out of 26 baclofen pump implantations (23%) in this cohort were identified to have seven infections despite vancomycin powder placement in the lumbar and catheter wounds. Prior infection rates have been investigated for intrathecal drug delivery systems from 2001 to 2009 at the same institution with an overall infection rate of 3% (8/274). The use of vancomycin powder in patients with implants in this series did not reduce infection rates compared to published historical controls, and was elevated compared to institutional controls. Further prospective study of this high risk patient population is warranted. PMID:24938386

Ghobrial, George M; Thakkar, Vismay; Singhal, Saurabh; Oppenlander, Mark E; Maulucci, Christopher M; Harrop, James S; Jallo, Jack; Prasad, Srinivas; Saulino, Michael; Sharan, Ashwini D

2014-10-01

205

Mini Implant Facilitated Accelerated Tooth Movement in Rats  

E-print Network

resorption.. In our study, we found a 44% and 55% increase in the number of osteoclasts in the total alveolarresorption and deposition is confined to discrete compartments; rather, these two dynamic processes can occur at any point in the alveolar

Cheung, Tracy Li

2014-01-01

206

Management of Grade III Mobile Anterior Tooth in Function Using Endostabilizer – A Case Report  

PubMed Central

Impact of implant dentistry is such that today very few dentists think about saving grade III mobile anterior teeth. A patient with grade III mobility of central incisor due to apical root resorption was treated by using 80 no.stainless steel ‘H’ file as endostabiliser and one year follow up was done. Endostabiliser reduced the mobility of grade III mobile teeth drastically, immediately after its placement. Tooth was absolutely asymptomatic throughout one year follow up. PMID:25654043

Patil, Swapnil N

2014-01-01

207

Long-term orthodontic tooth movement response to short-term force in the rat.  

PubMed

Both the amount of force applied and the duration of the application affect tooth movement. To study the effect of duration, adult male Sprague-Dawley rats were fitted with orthodontic appliances delivering a 40-gm initial mesial tipping force to the maxillary molars. The animals were divided into two longitudinal groups (I: 1 hour and II: 24 hours; N = 15). Sham-treated control (III) and 14 day (IV) continuous cross-sectional force tooth movement data were also included for comparison (72 rats per group). Extraoral cephalometric radiographs were obtained at appliance placement and at 1, 3, 5, 7, 10, & 14 days. Tooth movement was determined with respect to palatal implants. ANOVA indicated significant differences existed over time in each group (p = 0.0001). Continuous force applied for 14 days generated a classic three-part tooth movement curve. Short-term forces were characterized by initial mesial movement, a distal relapse period (d3-d5), and a late mesial movement period (d7-d14). The results suggest short-term forces of 1 and 24 hours initiate remodeling events, which result in tooth movement 7 to 14 days later and that the minimum effective duration of a 40-gm activation is less than 1 hour in this animal model. PMID:1416241

Gibson, J M; King, G J; Keeling, S D

1992-01-01

208

Prospective Single-Arm, Multi-Center Trial of a Patient-Specific Interpositional Knee Implant: Early Clinical Results  

PubMed Central

Background: The treatment of unicompartmental arthritis in younger patients is challenging. The aim of this study is to report final safety and efficacy analysis results for the iForma patient–specific interpositional device, which is designed for the treatment of isolated medial or lateral compartment arthritis of the knee. Methods: From June 2005 to June 2008 78 subjects (42 men, 36 women) received an iForma implant. The mean age was 53 years, the mean Body Mass Index 29.0. We surveyed the WOMAC scores, the visual analog pain scale and the Knee Society Scores. Results: The mean follow up was 16.4 months. The mean WOMAC knee scores increased from 48.3 before surgery to 71.3 after 24 months. A reduction in pain was achieved for all five pain measures using a standard visual analog scale (VAS). Knee Society Knee Score improved from 39.2 before to 61.9 24 month after surgery. The Knee Society Function Scores improved form preoperative 64.5 to 82.5 2 years postoperative. The preoperative range of motion could be restored. The overall revision rate was 24%. 15 implants were removed early, 4 knees were revised without implant removal. Conclusion: Within narrow indication of patients with unicompartmental disease, the iForma device can provide improvement in knee function and reduction in pain, however, with a significant higher risk of early revision compared to traditional arthroplasty. Respecting this limitation it may be an alternative option for arthritic patients with unicompartmental disease who have contraindications to High Tibial Osteotomy or are too young for knee replacement; the iForma device further has the distinct advantage of time and cost saving compared to those procedures. PMID:21552462

Koeck, F.X; Luring, C; Goetz, J; Handel, M; Tingart, M; Grifka, J; Beckmann, J

2011-01-01

209

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 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...

2011-04-01

210

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 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...

2010-04-01

211

21 CFR 872.3580 - Preformed gold denture tooth.  

...2014-04-01 2014-04-01 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...

2014-04-01

212

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 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...

2012-04-01

213

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 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...

2011-04-01

214

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 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...

2010-04-01

215

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...

2013-04-01

216

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section 872.3690...Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of...

2010-04-01

217

Esthesioneuroblastoma presenting as tooth pain  

PubMed Central

Esthesioneuroblastoma, also called olfactory neuroblastoma, is a rare malignant tumor originating in the olfactory epithelium in the upper nasal cavity with intracranial extension and may also be associated with secondary sinus diseases. Esthesioneuroblastoma has been observed to cause death by distant metastasis or by invasion through the cribriform plate and secondary meningitis. It usually produces nasal obstruction, epistaxis and less commonly anosmia, headache and pain. We report a case of esthesioneuroblastoma in a 50-year-old female who reported with tooth pain as a presenting symptom. PMID:25364164

Devi, Parvathi; Bhavle, Radhika; Aggarwal, Avanti; Walia, Cherry

2014-01-01

218

Immunomodulation Stimulates the Innervation of Engineered Tooth Organ  

PubMed Central

The sensory innervation of the dental mesenchyme is essential for tooth function and protection. Sensory innervation of the dental pulp is mediated by axons originating from the trigeminal ganglia and is strictly regulated in time. Teeth can develop from cultured re-associations between dissociated dental epithelial and mesenchymal cells from Embryonic Day 14 mouse molars, after implantation under the skin of adult ICR mice. In these conditions however, the innervation of the dental mesenchyme did not occur spontaneously. In order to go further with this question, complementary experimental approaches were designed. Cultured cell re-associations were implanted together with trigeminal ganglia for one or two weeks. Although axonal growth was regularly observed extending from the trigeminal ganglia to all around the forming teeth, the presence of axons in the dental mesenchyme was detected in less than 2.5% of samples after two weeks, demonstrating a specific impairment of their entering the dental mesenchyme. In clinical context, immunosuppressive therapy using cyclosporin A was found to accelerate the innervation of transplanted tissues. Indeed, when cultured cell re-associations and trigeminal ganglia were co-implanted in cyclosporin A-treated ICR mice, nerve fibers were detected in the dental pulp, even reaching odontoblasts after one week. However, cyclosporin A shows multiple effects, including direct ones on nerve growth. To test whether there may be a direct functional relationship between immunomodulation and innervation, cell re-associations and trigeminal ganglia were co-implanted in immunocompromised Nude mice. In these conditions as well, the innervation of the dental mesenchyme was observed already after one week of implantation, but axons reached the odontoblast layer after two weeks only. This study demonstrated that immunodepression per se does stimulate the innervation of the dental mesenchyme. PMID:24465840

Kökten, Tunay; Bécavin, Thibault; Keller, Laetitia; Weickert, Jean-Luc; Kuchler-Bopp, Sabine; Lesot, Hervé

2014-01-01

219

Tooth wear as a result of pica  

Microsoft Academic Search

This paper reports a case of tooth surface loss as a result of the eating disorder pica. Background to the condition is discussed and the clinical findings and treatment of the patient outlined. The case illustrates a rare cause of wear which should be considered when patients present with an unusual pattern of tooth surface loss.

D Barker

2005-01-01

220

Charcot-Marie-Tooth disease  

PubMed Central

Objectives: To determine the genetic distribution and the phenotypic correlation of an extensive series of patients with Charcot-Marie-Tooth disease in a geographically well-defined Mediterranean area. Methods: A thorough genetic screening, including most of the known genes involved in this disease, was performed and analyzed in this longitudinal descriptive study. Clinical data were analyzed and compared among the genetic subgroups. Results: Molecular diagnosis was accomplished in 365 of 438 patients (83.3%), with a higher success rate in demyelinating forms of the disease. The CMT1A duplication (PMP22 gene) was the most frequent genetic diagnosis (50.4%), followed by mutations in the GJB1 gene (15.3%), and in the GDAP1 gene (11.5%). Mutations in 13 other genes were identified, but were much less frequent. Sixteen novel mutations were detected and characterized phenotypically. Conclusions: The relatively high frequency of GDAP1 mutations, coupled with the scarceness of MFN2 mutations (1.1%) and the high proportion of recessive inheritance (11.6%) in this series exemplify the particularity of the genetic distribution of Charcot-Marie-Tooth disease in this region. PMID:24078732

Sivera, Rafael; Vílchez, Juan Jesús; Martínez-Rubio, Dolores; Chumillas, María José; Vázquez, Juan Francisco; Muelas, Nuria; Bataller, Luis; Millán, José María; Palau, Fancesc; Espinós, Carmen

2013-01-01

221

[Build-up restorations after extensive loss of tooth tissue].  

PubMed

After (extensive) loss of tooth tissue, vital teeth can be built up completely with composite restoration material. Sometimes, the application of additional retentive preparations is indicated. In exceptional cases, a root canal treatment is indicated, following which a root canal post is applied if necessary. Endodontically treated multi-rooted teeth can be built up entirely with composite, utilizing the pulp chamber and root canal accesses for retention. However, in single-rooted teeth a root canal post is necessary, in which case a prefabricated root post is used. Traditionally, metal posts were used in combination with a cast, indirect build-up restoration. Subsequently, directly fabricated cores, combining metal posts with amalgam or, at the present time, composite restoration material, became customary. The present trend is to use prefabricated or individually fabricated fibre-reinforced posts. After restoring a tooth with a build-up restoration, a combined build-up restoration can be chosen, or a direct or indirect crown single tooth prosthesis. PMID:23495567

Fokkinga, W A; Fennis, W M M; Witter, D J; Kreulen, C M; Creugers, N H J

2013-02-01

222

Intermediate term follow-up after a single-piece-acrylic intraocular lens implantation in the ciliary sulcus- a cross-sectional study  

PubMed Central

Background Implantation of a single-piece-acrylic intraocular lens (SPA-IOL) in the ciliary sulcus during phacoemulsification complicated with posterior capsule tear (PCT) may be associated with severe complications. The purpose of this study was to report the efficacy and safety of sulcus implantation of a SPA-IOL, designed for both in-the-bag and sulcus positioning. Methods A prospective cross-sectional study including 12 patients, who underwent phacoemulsification with PCT and sulcus implantation of SPA-IOL designed for both in-the-bag and sulcus positioning (Seelens AF, Hanita, Israel) between January 2009 and March 2012 (follow-up 12–37 months). Preoperatively corrected distance visual acuity (CDVA), subjective refraction and intraocular pressure (IOP) were recorded. Postoperative evaluation included anamnesis for IOL edge symptoms and transient visual obscurations (TVO) along with CDVA, subjective refraction IOP, anterior segment biomicroscopy, gonioscopy, assessment of IOL centration, fundus biomicroscopy and spectral-domain optical coherence tomography of the macula. Results Preoperatively, mean CDVA was 0.84?±?0.60 LogMAR (Counting Finger-20/33) improving to 0.18?±?0.13 LogMAR (20/40-20/20) at last examination (p?=?0.004), as all the patients gained better CDVA. Mean preoperative spherical equivalent was ?0.2?±?2.5 Diopter (D) (?4.0D to +5.4D) reaching ?1.9?±?0.9 (?4.0D to ?0.6D) at last examination (p?=?0.12). Mean preoperative refractive astigmatism magnitude was 1.0?±?0.6D (0.3D to 2.3D) changing to 1.1?±?1.0D (0.0D to 3.0D) at last examination (p?=?0.88). Mean preoperative IOP was 14.7?±?3.2 mmHg (11–23 mmHg) without medications reaching 15.9?±?3.3 mmHg (10–21 mmHg) at last follow up (p?=?0.21). Postoperatively one patient required two medications for IOP control in his study and contralateral eyes. None of the patients had symptoms of IOL edge or TVO. There were no intraocular hemorrhages, inflammatory reactions, or pigment dispersion and the IOLs were well centered in all cases. Central foveal thickness was 280?±?33 ?m (193–310 ?m). Conclusions Appropriately designed SPA-IOL may be implanted in the ciliary sulcus during phacoemulsification with PCT rather than switching to another backup IOL demanding wound enlargement. PMID:24321599

2013-01-01

223

A Retrospective Analysis of Ruptured Breast Implants  

PubMed Central

Background Rupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants. Methods We performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone), duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management. Results Forty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case), microfat graft (2 case), removal only (14 case), and follow-up loss (17 case). Conclusions Saline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs. PMID:25396188

Baek, Woo Yeol; Lew, Dae Hyun

2014-01-01

224

Graphene-based wireless bacteria detection on tooth enamel  

NASA Astrophysics Data System (ADS)

Direct interfacing of nanosensors onto biomaterials could impact health quality monitoring and adaptive threat detection. Graphene is capable of highly sensitive analyte detection due to its nanoscale nature. Here we show that graphene can be printed onto water-soluble silk. This in turn permits intimate biotransfer of graphene nanosensors onto biomaterials, including tooth enamel. The result is a fully biointerfaced sensing platform, which can be tuned to detect target analytes. For example, via self-assembly of antimicrobial peptides onto graphene, we show bioselective detection of bacteria at single-cell levels. Incorporation of a resonant coil eliminates the need for onboard power and external connections. Combining these elements yields two-tiered interfacing of peptide-graphene nanosensors with biomaterials. In particular, we demonstrate integration onto a tooth for remote monitoring of respiration and bacteria detection in saliva. Overall, this strategy of interfacing graphene nanosensors with biomaterials represents a versatile approach for ubiquitous detection of biochemical targets.

Mannoor, Manu S.; Tao, Hu; Clayton, Jefferson D.; Sengupta, Amartya; Kaplan, David L.; Naik, Rajesh R.; Verma, Naveen; Omenetto, Fiorenzo G.; McAlpine, Michael C.

2012-03-01

225

Cochlear Implants  

MedlinePLUS

... are better able to hear, comprehend sound and music, and speak than their peers who receive implants ... future hold for cochlear implants? With advancements in technology and continued follow-up studies with people who ...

226

Laser ultrasonic techniques for assessment of tooth structure  

NASA Astrophysics Data System (ADS)

Dental health care and research workers require a means of imaging the structures within teeth in vivo. For example, there is a need to image the margins of a restoration for the detection of poor bonding or voids between the restorative material and the dentin. With conventional x-ray techniques, it is difficult to detect cracks and to visualize interfaces between hard media. This due to the x-ray providing only a 2 dimensional projection of the internal structure (i.e. a silhouette). In addition, a high resolution imaging modality is needed to detect tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated which can help the tooth to re-mineralize itself. Currently employed x-ray imaging is incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration with a synthetic material. Other clinical applications include the visualization of periodontal defects, the localization of intraosseous lesions, and determining the degree of osseointegration between a dental implant and the surrounding bone. A means of assessing the internal structure of the tooth based upon use of high frequency, highly localized ultrasound (acoustic waves) generated by a laser pulse is discussed. Optical interferometric detection of ultrasound provides a complementary technique with a very small detection footprint. Initial results using laser-based ultrasound for assessment of dental structures are presented. Discussion will center on the adaptability of this technique to clinical applications.

Blodgett, David W.; Baldwin, Kevin C.

2000-06-01

227

High-Dose-Rate Brachytherapy of a Single Implant With Two Fractions Combined With External Beam Radiotherapy for Hormone-Naive Prostate Cancer  

SciTech Connect

Purpose: To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. Methods and Materials: Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. Results: Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). Conclusions: The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings.

Sato, Morio [Department of Radiology, Wakayama Medical University, Wakayama (Japan)], E-mail: morisato@mail.wakayama-med.ac.jp; Mori, Takashi [Department of Urology, Wakayama Medical University, Wakayama (Japan); Shirai, Shintaro; Kishi, Kazushi [Department of Radiology, Wakayama Medical University, Wakayama (Japan); Inagaki, Takeshi; Hara, Isao [Department of Urology, Wakayama Medical University, Wakayama (Japan)

2008-11-15

228

Peri-implant infections of oral biofilm etiology.  

PubMed

Biofilms are complex microbial communities that grow on various surfaces in nature. The oral micobiota tend to form polymicrobial biofilms, particularly on the hard mineralized surfaces of teeth, which may impact on oral health and disease. They can cause inflammation of the adjacent tooth-supporting (periodontal) tissues, leading to destructive periodontal disease and tooth loss. The emergence of osseointegrated dental implants as a restorative treatment option for replacing missing teeth has also brought along new artificial surfaces within the oral cavity, on which oral bacteria can form biofilms. As in the case of natural teeth, biofilms on implant surfaces may also trigger infection and cause inflammatory destruction of the peri-implant tissue (i.e. peri-implantitis). While there are strong similarities in the composition of the mixed microbial flora between periodontal and peri-implant infections, there are also a few distinctive differences. The immunological events underlying the pathogenesis of peri-implant infections are qualitatively similar, yet more extensive, compared to periodontal infections, resulting in a faster progression of tissue destruction. This chapter summarizes the current knowledge on the microbiology and immunology of peri-implant infections, including findings from the peri-implant crevicular fluid, the inflammatory exudate of the peri-implant tissue. Moreover, it discusses the diagnosis and current approaches for the treatment of oral infections. PMID:25366221

Belibasakis, Georgios N; Charalampakis, Georgios; Bostanci, Nagihan; Stadlinger, Bernd

2015-01-01

229

Ultrasonic assessment of tooth structure  

NASA Astrophysics Data System (ADS)

A means of assessing the internal structure of teeth based upon use of high frequency, highly localized ultrasound (acoustic waves) generated by a short laser pulse is discussed. Some key advantages of laser-generated ultrasound over more traditional contact transducer methods are that it is noncontact and nondestructive in nature and requires no special surface preparation. Optical interferometric detection of ultrasound provides a complementary nondestructive, noncontact technique with a very small detection footprint. This combination of techniques, termed laser-based ultrasonics, holds promise for future in-vivo diagnostics of tooth health. In this paper, initial results using laser-based ultrasound for assessment of dental structures are presented on an extracted human incisor. Results show the technique to be sensitive to the enamel/dentin, dentin/pulp, and dentin/cementum junctions as well as a region of dead tracts in the dentin.

Blodgett, David W.

2002-06-01

230

Consequences of Ti-, Li-, and Er-ion implantations on the optical properties of single layers of Ta 2 O 5  

NASA Astrophysics Data System (ADS)

Tantalum pentoxide (Ta2O5) layers made by ion plating are implanted with a high fluence of keV Ti, Li, and Er ions. The resulting refractive-index profiles are given from the analysis of guided-wave propagation conditions. A comparison with spectrophotometric measurements is presented. All the implanted layers present low losses (extinction coefficient of some 10-6) after thermal annealing in air. Ti-implanted layers exhibit an increase in refractive index, whereas Li- and Er-implanted layers present a slight decrease in refractive index. Er-implanted layers present photoluminescent properties.

Flory, F.; Berthier, D.; Rigneault, H.; Roux, L.

1996-09-01

231

Second-harmonic generation microscopy of tooth  

NASA Astrophysics Data System (ADS)

In this study, we have developed a high performance microscopic system to perform second-harmonic (SH)imaging on a tooth. The high sensitivity of the system allows an acquisition rate of 300 seconds/frame with a resolution at 512x512 pixels. The surface SH signal generated from the tooth is also carefully verified through micro-spectroscopy, polarization rotation, and wavelength tuning. In this way, we can ensure the authenticity of the signal. The enamel that encapsulates the dentine is known to possess highly ordered structures. The anisotrophy of the structure is revealed in the microscopic SH images of the tooth sample.

Kao, Fu-Jen; Wang, Yung-Shun; Huang, Mao-Kuo; Huang, Sheng-Lung; Cheng, Ping C.

2000-07-01

232

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs  

PubMed Central

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs. PMID:23874921

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

233

Biofilm and dental implant: The microbial link  

PubMed Central

Mouth provides a congenial environment for the growth of the microorganisms as compared to any other part of the human body by exhibiting an ideal nonshedding surface. Dental plaque happens to be a diverse community of the microorganisms found on the tooth surface. Periodontal disease and the peri-implant disease are specific infections that are originating from these resident microbial species when the balance between the host and the microbial pathogenicity gets disrupted. This review discusses the biofilms in relation to the peri-implant region, factors affecting its presence, and the associated treatment to manage this complex microbial colony. Search Methodology: Electronic search of the medline was done with the search words: Implants and biofilms/dental biofilm formation/microbiology at implant abutment interface/surface free energy/roughness and implant, periimplantitis/local drug delivery and dental implant. Hand search across the journals – clinical oral implant research, implant dentistry, journal of dental research, international journal of oral implantology, journal of prosthetic dentistry, perioodntology 2000, journal of periodontology were performed. The articles included in the review comprised of in vivo studies, in vivo (animal and human) studies, abstracts, review articles. PMID:23633764

Dhir, Sangeeta

2013-01-01

234

A longitudinal comparison of tooth whitening resulting from dentifrice use.  

PubMed

The effect of twice-daily brushing with one of three different dentifrices (Arm & Hammer Dental Care, Arm & Hammer Dental Care Extra Whitening, Crest) on stain removal and tooth whitening was examined in 115 volunteers over a period of 12 weeks. The facial surfaces of 12 anterior teeth were assessed for stain using a published, modified version of a standard stain index. Whiteness was measured on teeth 8 and 9 using a single Vita Lumin-Vaccum Shade Guide for consistency. At baseline, the mean facial stain scores were significantly higher (p < 0.05-0.01) for both Arm & Hammer dentifrices than for Crest. In addition, the tooth shades, as indicated by the stain guide, specifically the b* values representing yellowness, were quantified using a Minolta spectrophotometer. Arm & Hammer Dental Care Extra Whitening formula was found to be significantly better than Crest at removing naturally occurring extrinsic stain. The difference between Arm & Hammer Dental Care Extra Whitening and Crest became significant (p < 0.01) after two weeks of use, and remained intact during the balance of the study, achieving p values of 0.0002 for at least one of the three assessed parameters (total stain, proximal, and facial) at weeks 4 and 12. The study also found that Arm & Hammer Dental Care produced a significant increase in tooth whiteness by week 12, whereas Crest showed no such increase at any time during the study. These results suggest that the two Arm & Hammer Baking Soda products are more effective in reducing stain and increasing whiteness than the standard silica-based dentifrice. Their effectiveness is not related to abrasivity since they are less abrasive to tooth enamel than the silica-based product tested. PMID:10518865

Koertge, T E; Brooks, C N; Sarbin, A G; Powers, D; Gunsolley, J C

1998-01-01

235

Skeletal Muscle and Glioma Oxygenation by Carbogen Inhalation in Rats: A Longitudinal Study by EPR Oximetry Using Single-Probe Implantable Oxygen Sensors  

PubMed Central

The feasibility of EPR oximetry using a single-probe implantable oxygen sensor (ImOS) was tested for repeated measurement of pO2 in skeletal muscle and ectopic 9L tumors in rats. The ImOS (50 mm length) were constructed using nickel-chromium alloy wires, with lithium phthalocyanine (LiPc, oximetry probe) crystals loaded in the sensor loop and coated with AF 2400® Teflon. These ImOS were implanted into the skeletal muscle in the thigh and subcutaneous 9L tumors. Dynamic changes in tissue pO2 were assessed by EPR oximetry at baseline, during tumor growth, and repeated hyperoxygenation with carbogen breathing. The mean skeletal muscle pO2 of normal rats was stable and significantly increased during carbogen inhalation in experiments repeated for 12 weeks. The 9L tumors were hypoxic with a tissue pO2 of 12.8 ±6.4 mmHg on day 1; however, the response to carbogen inhalation varied among the animals. A significant increase in the glioma pO2 was observed during carbogen inhalation on day 9 and day 14 only. In summary, EPR oximetry with ImOS allowed direct and longitudinal oxygen measurements in deep muscle tissue and tumors. The heterogeneity of 9L tumors in response to carbogen highlights the need to repeatedly monitor pO2 to confirm tumor oxygenation so that such changes can be taken into account in planning therapies and interpreting results. PMID:24729220

Khan, Nadeem; Lariviere, Jean; Hodge, Sassan; Chen, Eunice Y.; Jarvis, Lesley A.; Eastman, Alan; Williams, Benjamin B.; Kuppusamy, Periannan; Swartz, Harold M.

2015-01-01

236

Biomaterials in Tooth Tissue Engineering: A Review  

PubMed Central

Biomaterials play a crucial role in the field of tissue engineering. They are utilized for fabricating frameworks known as scaffolds, matrices or constructs which are interconnected porous structures that establish a cellular microenvironment required for optimal tissue regeneration. Several natural and synthetic biomaterials have been utilized for fabrication of tissue engineering scaffolds. Amongst different biomaterials, polymers are the most extensively experimented and employed materials. They can be tailored to provide good interconnected porosity, large surface area, adequate mechanical strengths, varying surface characterization and different geometries required for tissue regeneration. A single type of material may however not meet all the requirements. Selection of two or more biomaterials, optimization of their physical, chemical and mechanical properties and advanced fabrication techniques are required to obtain scaffold designs intended for their final application. Current focus is aimed at designing biomaterials such that they will replicate the local extra cellular environment of the native organ and enable cell-cell and cell-scaffold interactions at micro level required for functional tissue regeneration. This article provides an insight into the different biomaterials available and the emerging use of nano engineering principles for the construction of bioactive scaffolds in tooth regeneration. PMID:24596804

Sharma, Sarang; Srivastava, Dhirendra; Grover, Shibani; Sharma, Vivek

2014-01-01

237

Dental Implants  

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... create a structure for the face and their loss can shift the surrounding teeth, creating esthetic issues and bite problems. A lost tooth can also affect facial structures such as the jaw, muscles, jaw joints, and even the skin. If several ...

238

Newer Technologies Find Tooth Decay Early  

MedlinePLUS

Newer Technologies Find Tooth Decay Early Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI) Digital Imaging: DIAGNOdent Quantitative Light-Induced ... early damage. Now some dentists are using newer technologies. Do these devices really do a better job ...

239

Peri-implantitis. Part 3: current modes of management.  

PubMed

Peri-implantitis is an inflammatory condition fuelled by the presence of bacteria on the implant surface. As such, in a similar manner to periodontal disease management, the removal of biofilm from the implant surface should result in regression of the disease process. The optimal manner with which this is achieved has yet to be realised. This may be unsurprising due to the relative surface complexity of the implant surface when compared to natural tooth root. Other management strategies include surface decontamination, the removal of implant threads known as implantoplasty, and in severe cases the need to explant. Favourable defects can be reconstructed utilising guided bone regeneration techniques. The current review appraises some of the techniques for the management of peri-implantitis. PMID:25303581

Alani, A; Bishop, K

2014-10-01

240

Tooth microwear formation rate in Gasterosteus aculeatus  

PubMed Central

Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. PMID:24773545

Baines, D C; Purnell, M A; Hart, P J B

2014-01-01

241

Tooth microwear formation rate in Gasterosteus aculeatus.  

PubMed

Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. PMID:24773545

Baines, D C; Purnell, M A; Hart, P J B

2014-05-01

242

Porcelain laminate veneer on a highly discoloured tooth: a case report.  

PubMed

Esthetic treatment of a single darkened tooth represents a great challenge to the dental practitioner. The properties of dental ceramic-colour stability, mechanical strength, clinical longevity, esthetic appearance and compatibility with periodontal tissues-make this material a good choice for such treatment. We present a case of restoration of a single, highly darkened anterior tooth with a feldspathic porcelain veneer. Resolution involved preparation of the dental structure guided by orientation grooves and provisional restoration using composite resin, a silicone impression and adhesive luting. Conservative use of porcelain laminate veneers provides satisfactory esthetic outcomes and preserves sound tooth structure. The patient was very satisfied with the result and had no complaints during 2 years of follow-up. PMID:20943031

Freire, Andrea; Archegas, Lucí Regina Panka

2010-01-01

243

Endodontic implants  

PubMed Central

Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

Yadav, Rakesh K.; Tikku, A. P.; Chandra, Anil; Wadhwani, K. K.; Ashutosh kr; Singh, Mayank

2014-01-01

244

Endodontic implants.  

PubMed

Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

Yadav, Rakesh K; Tikku, A P; Chandra, Anil; Wadhwani, K K; Ashutosh Kr; Singh, Mayank

2014-01-01

245

Patterns in ritual tooth avulsion at Roonka.  

PubMed

Tooth avulsion is the intentional removal of one or more teeth for ritual or aesthetic reasons, or to denote group affiliation. Typically the maxillary incisors are the teeth most often selected for removal. Previous authors have discussed the presence of tooth avulsions in several individuals recovered from Roonka, but those papers did not examine any patterns in those removals that might be present. Analysis of the tooth avulsions at Roonka reveals a change in the practice over time, with the older burials from phase II typically showing removal of both maxillary central incisors with a left side bias when only one tooth is removed, and the more recent phase III burials showing only one incisor avulsed and a right side bias for removal. Frequencies in the practice also changed over time, with avulsions being much more common in the older phase II burials. Historical evidence suggests that any particular regional or social group would have its own particular pattern of tooth avulsion, so these changes in tooth avulsions at Roonka suggest that the site was either used by multiple groups of people for burials, or that there was significant cultural change during the occupation of the site. PMID:24827419

Durband, Arthur C; Littleton, Judith; Walshe, Keryn

2014-08-01

246

Immediate implants in anterior maxillary arch  

PubMed Central

Aim: The aim of the study was to evaluate the osseo-integration and soft tissue status of the endosseous implants placed in immediate extraction socket. Methodology: Seven patients (4 males and 3 females) aged 20-30 years were selected for the study. Nine implants were placed in seven patients in the maxillary arch. All the patients were clinically ?nd thoroughly examined. Under local anesthesia, the indicated tooth was extracted. The extracted socket was prepared using standard drills with palatal wall as guide. The longest and widest implants were placed (Hi-Tec Implants). All implants showed good primary stability. The implants used in the study were tapered design endosseous implants with Threaded implants (TI) unit plasma-sprayed surface. Surgical re-entry (secondary surgery) was performed to remove the healing cap after 6 months for supra crestal fabrication. All patients were reviewed periodically at 3rd and 6th month interval and the following clinical parameters including modified plaque index (mPlI), modified bleeding index (mBI), probing depth (PD), attachment level (AL), and distance between the implant shoulder and mucosal margin (DIM), distance between the implant shoulder and first bone-implant contact, and Clinical Mobility Index were recorded. The results were computed and subjected to statistical evaluation. Results: The mPlI, mBI, PD, AL, and DIM were evaluated around the implants at baseline, 3rd and 6th month intervals and analyzed statistically by Friedman T-test. The results of the above were shown to be statistically non-significant. The distance between the implant shoulder and first bone implant contact was evaluated around the implants at base line, 3rd and 6th month intervals. The results proved to be statistically significant (0.01) implying that there was a bone apposition around the implants. Conclusion: During the course of the study, soft tissue status around implants was found to be healthy. Osseointegration as assessed by clinical and radiographic findings was found to be sound. PMID:24678203

Anitha, K.; Kumar, S. Senthil; Babu, M. R. Ramesh; Candamourty, Ramesh; Thirumurugan

2014-01-01

247

Mini-Implants: New Possibilities in Interdisciplinary Treatment Approaches  

PubMed Central

The introduction of mini-implants has broadened the range of tooth movements possible by fixed appliance therapy alone. The limits of fixed orthodontic treatment have become more a matter of facial appearance than anchorage. Many complex cases which would previously have required surgery or functional appliances can now be treated with fixed appliance therapy using mini-implants. A mutilated dentition case where mini-implants were used to provide anchorage for intrusion of molars and retraction of anterior teeth is reported here to illustrate this point. PMID:25580307

Sebastian, Biju

2014-01-01

248

Guided implant surgery with placement of a presurgical CAD/CAM patient-specific abutment and provisional in the esthetic zone.  

PubMed

Parallel use of implant treatment planning software and cone-beam computed tomography (CBCT) can, using certain criteria, consolidate steps and streamline tooth replacement strategies. The authors describe such a case in the esthetic zone whereby flapless extraction and immediate implant placement using CT-guided surgery were performed simultaneously, with placement of a computer-aided design/computer-aided manufactured (CAD/CAM) patient-specific abutment and non-occlusal function provisional in a single visit (supporting the "one-abutment, one-time" concept). An over-retained primary cuspid in a periodontally healthy woman with well-controlled type-2 diabetes was replaced with an implant and CAD/CAM patient-specific abutment in the No. 11 position. A necessary implant-axis angle correction was customized using digital information from a CBCT scan and implant treatment planning software, without the need for site development or a conventional impression. This data integration and streamlined workflow enabled fabrication of a CAD/CAM patient-specific abutment before surgical treatment. The abutment remained in place from implant surgery to the prosthetic phase, with minimal soft-tissue changes, enabling preservation of pink esthetics and expediting treatment. The result was a preserved emergence profile in the presence of high esthetic demands. However, due to slight post-extraction soft-tissue changes, digital reformatting of the abutment was required when the final crown was fabricated, thus limiting the disruption of the biologic width to a one-time occurrence. The importance of case selection for this treatment protocol in the esthetic zone cannot be overemphasized. A thick crestal dentoalveolar bone phenotype (> 1 mm, approaching 2 mm in this case), broad zone of attached and keratinized gingiva (3 mm to 4 mm in this case), adequate peri-implant soft-tissue thickness (> 1 mm in this case), and high primary implant stability (ISQ = 80 in this case) were all critical factors influencing outcome. PMID:25198877

Mandelaris, George A; Vlk, Scott D

2014-01-01

249

Comprehensive treatment approach for bilateral cleft lip and palate in an adult with premaxillary osteotomy, tooth autotransplantation, and 2-jaw surgery.  

PubMed

We report the successful treatment of a woman aged 25 years 3 months with bilateral cleft lip and palate. She had a protruded premaxilla, collapsed posterior segments, wide alveolar defects with oronasal fistulae, a congenital missing tooth, and severe facial asymmetry with a transverse occlusal cant. The comprehensive treatment approach included (1) premaxillary osteotomy combined with alveolar bone grafting to reposition the premaxilla and minimize the wide alveolar defects, (2) autotransplantation of a tooth with complete root formation to the grafted bone region to restore the missing tooth without a prosthesis such as a dental implant or bridge, and (3) 2-jaw surgery to improve facial asymmetry. The premaxillary osteotomy was managed orthodontically, in combination with bone grafting. The results suggest that surgical orthodontic treatment with tooth autotransplantation might be useful to improve the occlusion and facial esthetics without prosthetics. PMID:25533078

Kokai, Satoshi; Fukuyama, Eiji; Sato, Yutaka; Hsu, Jui-Chin; Takahashi, Yuzo; Harada, Kiyoshi; Ono, Takashi

2015-01-01

250

Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial  

PubMed Central

Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. Discussion This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Trial registration Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013) PMID:25152694

2014-01-01

251

[Implant allergies].  

PubMed

An increasing number of patients receive and benefit from osteosynthesis materials or artificial joint replacement. The most common complications are mechanical problems or infection. Metals like nickel, chromium and cobalt as well as bone cement components like acrylates and gentamicin are potential contact allergens which can cause intolerance reactions to implants. Eczema, delayed wound/bone healing, recurrent effusions, pain and implant loosening all have been described as manifestation of implant allergy. In contrast to the high incidence of cutaneous metal allergy, allergies associated with implants are rare. Diagnosis of metal implant allergy is still difficult. Thus differential diagnoses--in particular infection--have to be excluded and a combined approach of allergologic diagnostics by patch test and histopathology of peri-implant tissue is recommended. It is still unknown which conditions induce allergic sensitization to implants or trigger peri-implant allergic reactions in the case of preexisting cutaneous metal allergy. Despite the risk of developing complications being unclear, titanium based osteosynthesis materials are recommended for metal allergic patients and the use of metal-metal couplings in arthroplasty is not recommended for such patients. If the regular CoCr-polyethylene articulation is employed, the patient should give informed written consent. PMID:20204719

Thomas, P; Thomsen, M

2010-03-01

252

Tooth Wear Prevalence and Sample Size Determination : A Pilot Study  

PubMed Central

Tooth wear is the non-carious loss of tooth tissue, which results from three processes namely attrition, erosion and abrasion. These can occur in isolation or simultaneously. Very mild tooth wear is a physiological effect of aging. This study aims to estimate the prevalence of tooth wear among 16-year old Malay school children and determine a feasible sample size for further study. Fifty-five subjects were examined clinically, followed by the completion of self-administered questionnaires. Questionnaires consisted of socio-demographic and associated variables for tooth wear obtained from the literature. The Smith and Knight tooth wear index was used to chart tooth wear. Other oral findings were recorded using the WHO criteria. A software programme was used to determine pathological tooth wear. About equal ratio of male to female were involved. It was found that 18.2% of subjects have no tooth wear, 63.6% had very mild tooth wear, 10.9% mild tooth wear, 5.5% moderate tooth wear and 1.8 % severe tooth wear. In conclusion 18.2% of subjects were deemed to have pathological tooth wear (mild, moderate & severe). Exploration with all associated variables gave a sample size ranging from 560 – 1715. The final sample size for further study greatly depends on available time and resources. PMID:22589636

Abd. Karim, Nama Bibi Saerah; Ismail, Noorliza Mastura; Naing, Lin; Ismail, Abdul Rashid

2008-01-01

253

Tooth model reconstruction based upon data fusion for orthodontic treatment simulation.  

PubMed

This paper proposes a full tooth reconstruction method by integrating 3D scanner data and computed tomography (CT) image sets. In traditional dental treatment, plaster models are used to record patient?s oral information and assist dentists for diagnoses. However, plaster models only save surface information, and are therefore unable to provide further information for clinical treatment. With the rapid development of medical imaging technology, computed tomography images have become very popular in dental treatment. Computed tomography images with complete internal information can assist the clinical diagnosis for dental implants or orthodontic treatment, and a digital dental model can be used to simulate and predict results before treatment. However, a method of producing a high quality and precise dental model has yet to be developed. To this end, this paper presents a tooth reconstruction method based on the data fusion concept via integrating external scanned data and CT-based medical images. First, a plaster model is digitized with a 3D scanner. Then, each crown can be separated from the base according to the characteristics of tooth. CT images must be processed for feature enhancement and noise reduction, and to define the tooth axis direction which will be used for root slicing. The outline of each slice of dental root can then be determined by the level set algorithm, and converted to point cloud data. Finally, the crown and root data can be registered by the iterative closest point (ICP) algorithm. With this information, a complete digital dental model can be reconstructed by the Delaunay-based region-growing (DBRG) algorithm. The main contribution of this paper is to reconstruct a high quality customized dental model with root information that can offer significant help to the planning of dental implant and orthodontic treatment. PMID:24631784

Yau, Hong-Tzong; Yang, Tsan-Jui; Chen, Yi-Chen

2014-05-01

254

Custom-made, root-analogue direct laser metal forming implant: a case report.  

PubMed

In the last few years, the application of digital technology in dentistry has become widespread with the introduction of cone beam computed tomography (CBCT) scan technology, and considerable progress has been made in the development of computer-aided design/ computer-aided manufacturing (CAD/CAM) techniques, including direct laser metal forming (DLMF). DLMF is a technology which allows solids with complex geometry to be produced by annealing metal powder microparticles in a focused laser beam, according to a computer-generated three-dimensional (3D) model. For dental implants, the fabrication process involves the laser-induced fusion of titanium microparticles, in order to build, layer by layer, the desired object. At present, the combined use of CBCT 3D data and CAD/CAM technology makes it possible to manufacture custom-made, root-analogue implants (RAI) with sufficient precision. This report demonstrates the successful clinical use of a custom-made, root-analogue DLMF implant. CBCT images of a non-restorable right maxillary first premolar were acquired and transformed into a 3D model. From this model, a custom-made, root-analogue DLMF implant was fabricated. Immediately after tooth extraction, the RAI with a pre-operatively designed abutment was placed in the extraction socket and restored with a single crown. At the 1-year follow-up examination, the RAI showed a good functional and aesthetic integration. The introduction of DLMF technology signals the start of a new revolutionary era for implant dentistry as its immense potential for producing highly complex macro- and microstructures is receiving vast interest in different medical fields. PMID:22699801

Mangano, Francesco Guido; Cirotti, Bruno; Sammons, Rachel Lilian; Mangano, Carlo

2012-11-01

255

A stent fabricated on a selectively colored stereolithographic model for placement of orthodontic mini-implants.  

PubMed

The purpose of this report is to present a new method for placing orthodontic mini-implants using a stent fabricated on a selectively colored stereolithographic model. A stent was fabricated that incorporated a guide groove drilled in accordance with the planned direction of the mini-implant. Tooth crowns, gingiva, tooth roots, and the maxillary sinuses were clearly identified in the stereolithographic model. As a result, the stent could be fabricated while taking into account the anatomic characteristics of both the bone interior and the dental surface. A stent fabricated on the selectively colored stereolithographic model is suggested to be a promising device for guiding placement of orthodontic mini-implants adjacent to the tooth roots and the maxillary sinuses. PMID:12592997

Kitai, Noriyuki; Yasuda, Yoshitaka; Takada, Kenji

2002-01-01

256

The evolution of dinosaur tooth enamel microstructure.  

PubMed

The evolution of tooth enamel microstructure in both extinct and extant mammalian groups has been extensively documented, but is poorly known in reptiles, including dinosaurs. Previous intensive sampling of dinosaur tooth enamel microstructure revealed that: (1) the three-dimensional arrangement of enamel types and features within a tooth-the schmelzmuster-is most useful in diagnosing dinosaur clades at or around the family level; (2) enamel microstructure complexity is correlated with tooth morphology complexity and not necessarily with phylogenetic position; and (3) there is a large amount of homoplasy within Theropoda but much less within Ornithischia. In this study, the examination of the enamel microstructure of 28 additional dinosaur taxa fills in taxonomic gaps of previous studies and reinforces the aforementioned conclusions. Additionally, these new specimens reveal that within clades such as Sauropodomorpha, Neotheropoda, and Euornithopoda, the more basal taxa have simpler enamel that is a precursor to the more complex enamel of more derived taxa and that schmelzmusters evolve in a stepwise fashion. In the particularly well-sampled clade of Euornithopoda, correlations between the evolution of dental and enamel characters could be drawn. The ancestral schmelzmuster for Genasauria remains ambiguous due to the dearth of basal ornithischian teeth available for study. These new specimens provide new insights into the evolution of tooth enamel microstructure in dinosaurs, emphasizing the importance of thorough sampling within broadly inclusive clades, especially among their more basal members. PMID:20518758

Hwang, Sunny H

2011-02-01

257

Cochlear implants.  

PubMed

Cochlear implants are the first example of a neural prosthesis that can substitute a sensory organ: they bypass the malfunctioning auditory periphery of profoundly-deaf people to electrically stimulate their auditory nerve. The history of cochlear implants dates back to 1957, when Djourno and Eyriès managed, for the first time, to elicit sound sensations in a deaf listener using an electrode implanted in his inner ear. Since then, considerable technological and scientific advances have been made. Worldwide, more than 300,000 deaf people have been fitted with a cochlear implant; it has become a standard clinical procedure for born-deaf children and its success has led over the years to relaxed patient selection criteria; for example, it is now not uncommon to see people with significant residual hearing undergoing implantation. Although the ability to make sense of sounds varies widely among the implanted population, many cochlear implant listeners can use the telephone and follow auditory-only conversations in quiet environments. PMID:25247367

Macherey, Olivier; Carlyon, Robert P

2014-09-22

258

Measurement accuracy and reliability of tooth length on conventional and CBCT reconstructed panoramic radiographs  

PubMed Central

INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventional panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%.

Flores-Mir, Carlos; Rosenblatt, Mark R; Major, Paul W.; Carey, Jason P.; Heo, Giseon

2014-01-01

259

The unicorn and the narwhal: a tale of the tooth.  

PubMed

From as far back as the early Roman era, detailed descriptions and artistic images of the unicorn have been imagined. In Europe, the Mediterranean and the Far East, this creature became accepted as real. Although such an animal had never actually been seen, it was said to have the appearance of a horse, the beard and cloven hooves of a goat, the tail of a lion, and a single, spear-like horn protruding from the center of its forehead. The unicorn myth originated shortly after unidentified horn-like objects, from six to ten feet long, began to appear in ancient European marketplaces. Physicians quickly ascribed outlandish healing properties to these horns, pulverizing them for the treatment of various diseases. In 1638, a Danish zoologist challenged these claims and provided evidence that the so-called "unicorn horn" was actually the tusk (tooth) of the narwhal from the Arctic seas. However, his findings remained unheeded for the next 100 years. This paper explains how the myth of the unicorn and the purported powers contained within the substance of its magical horn evolved from the ages-old spoils of the Arctic fishing trade, where the narwhal was primarily speared for food and secondarily, for the export value of its ivory tusk. This unusually long, pointed and protruding single tooth, which breaks through the upper lip and the left jaw of each male narwhal, became a highly valuable commodity over the following centuries, due to its believed supernatural origins and curative qualities. PMID:22372187

Christen, Arden G; Christen, Joan A

2011-01-01

260

A comparison of peripheral marginal bone loss at dental implants measured with conventional intraoral film and digitized radiographs.  

PubMed

The purpose of the present study was to examine the effects of conventional and bone-condensing implantation techniques and time (6 and 12 months after implantation) on levels of marginal bone surrounding implants and to assess the level of agreement between measurements made using digitized intraoral images and film. The study group consisted of 14 healthy patients (9 female, 5 male; age range, 23-59 years; mean age, 41.1 years) with 28 single-tooth dental implants. In each patient, an implant was placed on one side using a conventional technique and on the opposite side using a bone-condensing technique. Film radiographs were taken at 6 and 12 months following implant placement and were digitized at 300 dpi and 600 dpi using a laser scanner. All scanned images were stored as both TIFF and JPEG files. A single observer twice measured distal and mesial marginal bone loss from film and digitized images. At the mesial site, there was a significant main effect of time (6 and 12 months after implantation) on the measurement of bone loss, F(1, 26) = 6.08, P = .02, but no significant main effect of implantation technique, F(1, 26) = 1.56, P = .223, and no significant interaction between time and technique, F(1, 26) = 2.09, P = .160. Similarly, at the distal site, there was a significant main effect of time on the measurement of bone loss, F(1, 26) = 14.1, P = .001, but no significant main effect of implantation technique, F(1, 26) = 1.21, P = .281. However, in contrast to the mesial site, there was also significant interaction between technique and time on the distal site, F(1, 26) = 4.974, P = .035. Intraobserver intraclass correlation coefficients and repeatability measurements showed high agreement for all image types. The bone-condensing technique resulted in greater marginal bone loss. Marginal bone measurements made using digitized intraoral images and conventional film showed high levels of agreement. PMID:20712442

Kamburo?lu, K?vanç; Gül?ah?, Ay?e; Genç, Yasemin; Paksoy, Candan Semra

2012-06-01

261

PKA regulatory subunit expression in tooth development.  

PubMed

Protein kinase A (PKA) plays critical roles in many biological processes including cell proliferation, cell differentiation, cellular metabolism and gene regulation. Mutation in PKA regulatory subunit, PRKAR1A has previously been identified in odontogenic myxomas, but it is unclear whether PKA is involved in tooth development. The aim of the present study was to assess the expression of alpha isoforms of PKA regulatory subunit (Prkar1a and Prkar2a) in mouse and human odontogenesis by in situ hybridization. PRKAR1A and PRKAR2A mRNA transcription was further confirmed in a human deciduous germ by qRT-PCR. Mouse Prkar1a and human PRKAR2A exhibited a dynamic spatio-temporal expression in tooth development, whereas neither human PRKAR1A nor mouse Prkar2a showed their expression in odontogenesis. These isoforms thus showed different expression pattern between human and mouse tooth germs. PMID:24755349

de Sousa, Sílvia Ferreira; Kawasaki, Katsushige; Kawasaki, Maiko; Volponi, Ana Angelova; Gomez, Ricardo Santiago; Gomes, Carolina Cavaliéri; Sharpe, Paul T; Ohazama, Atsushi

2014-05-01

262

Tooth-derived bone graft material  

PubMed Central

With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

2013-01-01

263

Autogenous Tooth Transplantation as a Treatment Option  

PubMed Central

ABSTRACT Autogenous tooth transplantation is the surgical movement of a tooth from one location in the mouth to another in the same individual. Though done for years but it has achieved variable success rates. Although the indications for autotransplantation are narrow, careful patient selection coupled with an appropriate technique can lead to exceptional esthetic and functional results. This article discusses the reviews of previous works done and highlights the criteria and factors influencing the success of autotransplant along with reports of two cases of transplantation of impacted and malposed canine. How to cite this article: Chugh A, Aggarwal R, Chugh VK, Wadhwa P, Kohli M. Autogenous Tooth Transplantation as a Treatment Option. Int J Clin Pediatr Dent 2012;5(1):87-92. PMID:25206143

Aggarwal, Rashmi; Chugh, Vinay Kumar; Wadhwa, Puneet; Kohli, Munish

2012-01-01

264

Interactive tooth partition of dental mesh base on tooth-target harmonic field.  

PubMed

The accurate tooth partition of dental mesh is a crucial step in computer-aided orthodontics. However, tooth boundary identification is not a trivial task for tooth partition, since different shapes and their arrangements vary substantially among common clinical cases. Though curvature field is traditionally used for identifying boundaries, it is normally not reliable enough. Other methods may improve the accuracy, but require intensive user interaction. Motivated by state-of-the-art general interactive mesh segmentation methods, this paper proposes a novel tooth-target partition framework that employs harmonic fields to partition teeth accurately and effectively. In addition, a refining strategy is introduced to successfully segment teeth from the complicated dental model with indistinctive tooth boundaries on its lingual side surface, addressing an issue that had not been solved properly before. To utilise high-level information provided by the user, smart and intuitive user interfaces are also proposed with minimum interaction. In fact, most published interactive methods specifically designed for tooth partition are lacking efficient user interfaces. Extensive experiments and quantitative analyses show that our tooth partition method outperforms the state-of-the-art approaches in terms of accuracy, robustness and efficiency. PMID:25464355

Zou, Bei-Ji; Liu, Shi-Jian; Liao, Sheng-Hui; Ding, Xi; Liang, Ye

2015-01-01

265

Nucleotide variants of genes encoding components of the Wnt signalling pathway and the risk of non-syndromic tooth agenesis.  

PubMed

Tooth agenesis is one of the most common dental anomalies, with a complex and not yet fully elucidated aetiology. Given the crucial role of the Wnt signalling pathway during tooth development, the purpose of this study was to determine whether nucleotide variants of genes encoding components of this signalling pathway might be associated with hypodontia and oligodontia in the Polish population. A set of 34 single nucleotide polymorphism (SNPs) in 13 WNT and WNT-related genes were analyzed in a group of 157 patients with tooth agenesis and a properly matched control group (n?=?430). In addition, direct sequencing was performed to detect mutations in the MSX1, PAX9 and WNT10A genes. Both single-marker and haplotype analyses showed highly significant association between SNPs in the WNT10A gene and the risk for tooth agenesis. Moreover, nine pathogenic mutations within the coding region of the WNT10A gene were identified in 26 out of 42 (62%) tested patients. One novel heterozygous mutation was identified in the PAX9 gene. Borderline association with the risk of non-syndromic tooth agenesis was also observed for the APC, CTNNB1, DVL2 and WNT11 polymorphisms. In conclusion, nucleotide variants of genes encoding important components of the Wnt signalling pathway might influence the risk of tooth agenesis. PMID:23167694

Mostowska, A; Biedziak, B; Zadurska, M; Dunin-Wilczynska, I; Lianeri, M; Jagodzinski, P P

2013-11-01

266

Breast Implants  

MedlinePLUS

... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Medical Devices Print this page Share this page E-mail this page Home Medical Devices Products and Medical Procedures Implants and Prosthetics Breast ...

267

The Pathology of Bone Tissue during Peri-Implantitis.  

PubMed

Dental implants are one of the most frequently used treatment options for tooth replacement. Approximately 30% of patients with dental implants develop peri-implantitis, which is an oral inflammatory disease that leads to loss of the supporting tissues, predominately the bone. For the development of future therapeutic strategies, it is essential to understand the molecular pathophysiology of human dental peri-implant infections. Here, we describe the gene and protein expression patterns of peri-implantitis bone tissue compared with healthy peri-implant bone tissue. Furthermore, cells from the osteoblastic lineage derived from peri-implantitis samples were immortalized and characterized. We applied microarray, quantitative reverse transcription polymerase chain reaction, fluorescence-activated cell sorting, and Western blot analyses. The levels of typical bone matrix molecules, including SPP1, BGLAP, and COL9A1, in patients with peri-implantitis were reduced, while the inflammation marker interleukin 8 (IL8) was highly expressed. RUNX2, one of the transcription factors of mature osteoblasts, was also decreased in peri-implantitis. Finally, the human telomerase reverse transcriptase immortalized cell line from peri-implantitis exhibited a more fibro-osteoblastic character than did the healthy control. PMID:25406169

Schminke, B; Vom Orde, F; Gruber, R; Schliephake, H; Bürgers, R; Miosge, N

2015-02-01

268

Are You Feeding Your Kids Tooth-Friendly Foods?  

MedlinePLUS

... can limit the risk of tooth decay. Choose milk or water, instead of sugary drinks or juice. ... teeth. This can contribute to tooth decay. Choosing milk or water will help ensure a healthy mouth ...

269

Seal Out Tooth Decay: A Fact Sheet for Parents  

MedlinePLUS

... sealants is to avoid tooth decay. • Fluoride in toothpaste and in drinking water protects the smooth surfaces ... ways to prevent tooth decay? Yes. Using fluoride toothpaste and drinking fluoridated water can help protect teeth ...

270

Ectopic tooth in maxillary sinus: Case series  

PubMed Central

Ectopic eruption of a tooth within the dentate region of the jaws is often noticed in clinical practice and is well documented in the literature. But the ectopic eruption into the non dentate region is rare and scantly documented. The maxillary sinus is one such a non dentate region, apart from nasal septum, mandibular condyle, coronoid process and the palate, to accommodate such ectopic eruptions of teeth. Due to its rarity and lack of consensus over its management, the incidence deserves to be added to the literature and discussed. Early surgical intervention for removal of ectopic tooth along with enucleation of the associated cyst, if any, is the treatment of choice. PMID:23662268

Ramanojam, Shandilya; Halli, Rajshekhar; Hebbale, Manjula; Bhardwaj, Smita

2013-01-01

271

Aesthetic replacement of an anterior tooth using the natural tooth as a pontic; an innovative technique  

PubMed Central

This article presents a novel technique for replacing an anterior tooth. A new modification to the clinical technique of direct fabrication of a resin-bonded bridge was employed, in which the patient’s natural tooth was used as a pontic. Treatment with this modification led to overall improved aesthetics and reduced treatment cost. The natural tooth pontic was stabilized in the extraction socket with a resin-wire splint as a provisional restoration to maintain the gingival architecture while the permanent bridge was being constructed. PMID:24179322

Purra, Aamir Rashid; Mushtaq, Mubashir

2013-01-01

272

Tooth discoloration induced by endodontic materials: a literature review.  

PubMed

It is common knowledge that materials used in endodontics may cause discoloration and thus impair the aesthetic outcome of the treated tooth. The purpose of this review is to summarise the existing knowledge on the discoloration potential of materials used for endodontic procedures. A comprehensive literature search covering the period from 1966 to 2011 was conducted on Pubmed and the Cochrane Library using different keyword combinations including 'tooth', 'colour', 'discoloration', 'staining', 'endodontic''root canal''sealer', 'dressing', 'medicament', 'obturation', 'filling', 'treatment', 'portland cement', 'MTA' and 'antibiotic paste'. Any relevant work published in the English language in peer-reviewed journals and presenting pertinent information related to the purpose of this overview was considered for inclusion. In addition, bibliographies of all relevant papers and previous review articles were hand searched and the reference lists from endodontic textbooks were also reviewed. Articles were excluded if an English abstract was unavailable, if only single clinical reports or conference reports were included, or if the topic was unrelated to the subject. Ten in-vitro studies, one randomized controlled trial and one multicenter randomized controlled trial met the inclusion criteria. There were not any recently used endodontic materials that would not induce at least measurable colour changes. For a wide range of materials currently available on the market there is only scarce or no evidence available on their staining ability. Endodontic therapy should not focus solely on biological and functional aspects, but take aesthetic considerations into account as well. To reduce the risk of material-induced tooth discoloration all materials should be applied carefully in areas of aesthetic concern. The need for further research in this field and for the development of non-staining endodontic materials is evident. PMID:22513082

Krastl, Gabriel; Allgayer, Nikola; Lenherr, Patrik; Filippi, Andreas; Taneja, Pankaj; Weiger, Roland

2013-02-01

273

Corticotomy-\\/Osteotomy-assisted Tooth Movement microCTs Differ  

Microsoft Academic Search

Corticotomy-assisted and osteotomy-assisted tooth movement involves surgical incisions through the alveolar bone. To ascertain whether teeth move by distraction osteogenesis or by regional accelerated phenomenon (RAP), we randomly assigned 30 Sprague-Dawley rats to one of 5 experimental groups: corticotomy alone, corticotomy-assisted tooth movement, osteotomy alone, osteotomy-assisted tooth movement, or tooth movement alone. Each animal was imaged by microtomography immediately after

W. Lee; G. Karapetyan; R. Moats; D.-D. Yamashita; H.-B. Moon; D. J. Ferguson; S. Yen

2008-01-01

274

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2011-04-01

275

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2012-04-01

276

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2013-04-01

277

The Importance of Tooth Decay Prevention in Children under Three  

ERIC Educational Resources Information Center

Tooth decay and tooth loss was once the norm but public health interventions have led to major improvements for most people. Nevertheless, not all children have benefited. Dental disease in young children is unacceptably high. Tooth decay is preventable. Early childhood educators are often the first to notice the problem. Professional…

Milgrom, Peter; Huebner, Colleen; Chi, Donald

2010-01-01

278

Reduction of Gear Pair Transmission Error with Tooth Profile Modification  

Microsoft Academic Search

The gear noise problem that widely occurs in power transmission systems is typically characterised by one or more high amplitude acoustic signals. The noise originates from the vibration of the gear pair system caused by transmission error excitation that arises from tooth profile errors, misalignment and tooth deflections. This paper aims to further research the effect of tooth profile modifications

R. Tharmakulasingam; G. Alfano; M Atherton

279

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2010-04-01

280

Dielectric response of the human tooth dentine  

Microsoft Academic Search

Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters ?v0 and ?v, indicating the deposition of AgCl in the dentine tubules during the duration of the

J. Leskovec; C. Filipic; A. Levstik

2005-01-01

281

Computed tomography to quantify tooth abrasion  

NASA Astrophysics Data System (ADS)

Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

2010-09-01

282

Tooth wear: diet analysis and advice.  

PubMed

Diet analysis and advice for patients with tooth wear is potentially the most logical intervention to arrest attrition, erosion and abrasion. It is saliva that protects the teeth against corrosion by the acids which soften enamel and make it susceptible to wear. Thus the lifestyles and diet of patients at risk need to be analysed for sources of acid and reasons for lost salivary protection. Medical conditions which put patients at risk of tooth wear are principally: asthma, bulimia nervosa, caffeine addiction, diabetes mellitus, exercise dehydration, functional depression, gastroesophageal reflux in alcoholism, hypertension and syndromes with salivary hypofunction. The sources of acid are various, but loss of salivary protection is the common theme. In healthy young Australians, soft drinks are the main source of acid, and exercise dehydration the main reason for loss of salivary protection. In the medically compromised, diet acids and gastroesophageal reflux are the sources, but medications are the main reasons for lost salivary protection. Diet advice for patients with tooth wear must: promote a healthy lifestyle and diet strategy that conserves the teeth by natural means of salivary stimulation; and address the specific needs of the patients' oral and medical conditions. Individualised, patient-empowering erosion WATCH strategies; on Water, Acid, Taste, Calcium and Health, are urgently required to combat the emerging epidemic of tooth wear currently being experienced in westernised societies. PMID:15880960

Young, William George

2005-04-01

283

Positioning the actual interference fringe pattern on the tooth flank in measuring gear tooth flanks by laser interferometry  

NASA Astrophysics Data System (ADS)

In measuring form deviation of gear tooth flanks by laser interferometry, the collected interference fringe pattern (IFP) is badly distorted, in the case of shape, relative to the actual tooth flank. Meanwhile, a clear and definite mapping relationship between the collected IFP and the actual tooth flank is indispensable for both transforming phase differences into deviation values and positioning the measurement result on the actual tooth flank. In order to solve these problems, this paper proposes a method using the simulation tooth image as a bridge connecting the actual tooth flank and the collected IFP. The mapping relationship between the simulation tooth image and the actual tooth flank has been obtained by ray tracing methods [Fang et al., Appl. Opt. 49(33), 6409-6415 (2010)]. This paper mainly discusses how to build the relationship between the simulation tooth image and the collected IFP by using a matching algorithm of two characteristic point sets. With the combination of the two above-mentioned assistant mapping relationships, the mapping relationship between the collected IFP and the actual tooth flank can be built; the collected IFP can be positioned on the actual tooth flank. Finally, the proposed method is employed in a measurement of the form deviation of a gear tooth flank and the result proves the feasibility of the proposed method.

Fang, Suping; Wang, Leijie; Liu, Shiqiao; Komori, Masaharu; Kubo, Aizoh

2011-05-01

284

A 3-year follow-up study of all-ceramic single and multiple crowns performed in a private practice: a prospective case series  

PubMed Central

OBJECTIVES: Zirconia-based prostheses are commonly used for aesthetic crown and fixed restorations, although follow-up data are limited, especially for implant-supported crowns. The aim of this study was to evaluate the three-year clinical results of the installation of 463 zirconia core crowns by a general dental private practice. METHODS: This study followed 142 patients (69 men and 73 women; aged 28-82 years) who had received 248 single crowns (202 tooth-supported, 36 implant-supported) and 225 multiple units of up to six elements (81 tooth-supported, 144 implant-supported). Clinical events, including fracture and loss of retention, secondary caries, and marginal integrity, were recorded. The overall failure rate was computed for the fractured and lost prostheses. Aesthetic, functional, and biological properties were rated, and patient satisfaction was investigated. RESULTS: During the three-year follow-up period, four patients were lost from the study (18 crowns, 4% of the total crowns). Three of the zirconia prostheses suffered fractures in more than three units (11 crowns; one- vs. three-year follow-up, p<0.05, Wilcoxon signed-rank test), and the cumulative prosthesis survival rate was 98.2%. Twelve units lost retention and were re-cemented, and no secondary caries of the abutment teeth were reported. The aesthetic, functional, and biological properties were generally well-rated, and there were no differences between tooth- and implant-supported crowns. The lowest scores were given regarding the anatomical form of the crowns, as some minor chipping was reported. Relatively low scores were also given for the periodontal response and the adjacent mucosa. Overall, patient satisfaction was high. CONCLUSIONS: At the three-year follow-up, the zirconia-core crowns appeared to be an effective clinical solution as they had favorable aesthetic and functional properties. Only the marginal fit of the prostheses should be improved upon. PMID:22189731

Tartaglia, Gianluca M.; Sidoti, Ernesto; Sforza, Chiarella

2011-01-01

285

Mesiodistal tooth width and tooth size discrepancies of Yemeni Arabians: A pilot study  

PubMed Central

Objectives: The aims of this study were to determine the mean mesiodistal tooth size width and Bolton's anterior and overall ratios, find any possible sex differences, and study the frequency of tooth size discrepancies among Yemeni population and if there is a difference in tooth size between the right and left sides. Materials and Methods: 176 subjects aged 13–25 years (94 females and 82 males) with different types of malocclusions (94 Angle Class I, 37 Class II division 1, 36 Class II division 2, and 9 Class III) were included in the present study. The mean mesiodistal tooth size width and Bolton's ratios were determined. Results: The results showed that males had significantly larger teeth than females. The prevalence rates of clinically significant discrepancy greater than 2 SD were 29.53% and 14.20% in the anterior and overall tooth size ratios, respectively. Further, the results revealed that there were no significant differences in the tooth size width between right and left sides. Conclusion: The findings of the present study indicate that there was no significant difference between Bolton's ratio and that of Yemeni population. PMID:24987624

Al-Gunaid, Talat; Yamaki, Masaki; Saito, Isao

2012-01-01

286

Effect of cardiac resynchronization therapy with implantable cardioverter defibrillator versus cardiac resynchronization therapy with pacemaker on mortality in heart failure patients: results of a high-volume, single-centre experience  

PubMed Central

Aims There are limited and contradictory data on the effects of CRT with implantable cardioverter defibrillator (CRT-D) on mortality as compared with CRT with pacemaker (CRT-P). Methods and results We evaluated the long-term outcome of patients implanted with a CRT-D or CRT-P device in our high-volume single-centre experience. Data on all-cause mortality were derived from clinic visits and the Hungarian National Healthcare Fund Death Registry. Kaplan–Meier survival analyses and multivariate Cox regression models were used to evaluate all-cause mortality in patients with CRT-D vs. CRT-P, stratified by the aetiology of cardiomyopathy. From 2000 to 2011, 1122 CRT devices, 693 CRT-P (LVEF 28.2?±?7.4%) and 429 CRT-D (LVEF 27.6?±?6.4%), were implanted at our centre. During the median follow-up of 28 months, 379 patients died from any cause, 250 patients (36%) with an implanted CRT-P and 129 patients (30%) with an implanted CRT-D. There was no evidence of mortality benefit in patients implanted with a CRT-D compared with a CRT-P in the total cohort [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.73–1.32, P?=?0.884]. In patients with ischaemic cardiomyopathy, CRT-D treatment was associated with a significant 30% risk reduction in all-cause mortality compared with an implanted CRT-P (HR 0.70, 95% CI 0.51–0.97, P?=?0.03). In non-ischaemic patients, there was no mortality benefit of CRT-D over CRT-P (HR 0.98, 95% CI 0.73–1.32, P?=?0.894, interaction P-value?=?0.15). Conclusions In heart failure patients with ischaemic cardiomyopathy, CRT-D was associated with a mortality benefit compared with CRT-P, but no benefit of CRT-D over CRT-P in mortality was observed in non-ischaemic cardiomyopathy. PMID:25379962

Kutyifa, Valentina; Geller, Laszlo; Bogyi, Peter; Zima, Endre; Aktas, Mehmet K; Ozcan, Emin Evren; Becker, David; Nagy, Vivien Klaudia; Kosztin, Annamaria; Szilagyi, Szabolcs; Merkely, Bela

2014-01-01

287

Aesthetic Rehabilitation of a Complicated Crown-Root Fracture of the Maxillary Incisor: Combination of Orthodontic and Implant Treatment  

PubMed Central

The aim of this paper is to present a complex rehabilitation, of fractured tooth, with implants in anterior region considering the orthodontics extrusion to clinical success. At 7 years old, the patient fractured the maxillary left central incisor and the dentist did a crown with the fragment. Twenty years later, the patient was referred to a dental clinic for orthodontic treatment, with the chief complaint related to an accentuated deep bite, and a professional started an orthodontic treatment. After sixteen months of orthodontic treatment, tooth 21 fractured. The treatment plan included an orthodontic extrusion of tooth 21 and implant placement. This case has been followed up and the clinical and radiographic examinations show excellence esthetic results and satisfaction of patient. The forced extrusion can be a viable treatment option in the management of crown root fracture of an anterior tooth to gain bone in a vertical direction. This case emphasizes that to achieve the esthetic result a multidisciplinary approach is necessary. PMID:24872900

de Avila, Érica Dorigatti; de Molon, Rafael Scaf; Cardoso, Mauricio de Almeida; Capelozza Filho, Leopoldino; Campos Velo, Marilia Mattar de Amoêdo; Mollo, Francisco de Assis; Borelli Barros, Luiz Antonio

2014-01-01

288

Hip Implant Systems  

MedlinePLUS

... Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Section Contents Menu Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants The Hip Joint Hip ...

289

Computer aided design and analysis of gear tooth geometry  

NASA Technical Reports Server (NTRS)

A simulation method for gear hobbing and shaping of straight and spiral bevel gears is presented. The method is based upon an enveloping theory for gear tooth profile generation. The procedure is applicable in the computer aided design of standard and nonstandard tooth forms. An inverse procedure for finding a conjugate gear tooth profile is presented for arbitrary cutter geometry. The kinematic relations for the tooth surfaces of straight and spiral bevel gears are proposed. The tooth surface equations for these gears are formulated in a manner suitable for their automated numerical development and solution.

Chang, S. H.; Huston, R. L.

1987-01-01

290

Contribution of donor and host mesenchyme to the transplanted tooth germs.  

PubMed

Autologous tooth germ transplantation of immature teeth is an alternative method of tooth replacement that could be used instead of dental implants in younger patients. However, it is paramount that the dental pulp remain vital and that root formation continue in the transplanted location. The goal of this study is to characterize the healing of allogenic tooth grafts in an animal model using GFP-labeled donor or host postnatal mice. In addition, the putative stem cells were labeled before transplantation with a pulse-chase paradigm. Transplanted molars formed cusps and roots and erupted into occlusion by 2 wk postoperatively. Host label-retaining cells (LRCs) were maintained in the center of pulp tissue associating with blood vessels. Dual labeling showed that a proportion of LRCs were incorporated into the odontoblast layer. Host cells, including putative dendritic cells and the endothelium, also immigrated into the pulp tissue but did not contribute to the odontoblast layer. Therefore, LRCs or putative mesenchymal stem cells are retained in the transplanted pulps. Hertwig's epithelial root sheath remains vital, and epithelial LRCs are present in the donor cervical loops. Thus, the dynamic donor-host interaction occurred in the developing transplant, suggesting that these changes affect the characteristics of the dental pulp. PMID:25376722

Nakaki, T; Saito, K; Ida-Yonemochi, H; Nakagawa, E; Kenmotsu, S; Ohshima, H

2015-01-01

291

An overview of zirconia dental implants: basic properties and clinical application of three cases.  

PubMed

Due to the possible aesthetic problems of titanium implants, the developments in ceramic implant materials are increasing. Natural tooth colored ceramic implants may be an alternative to overcome aesthetic problems. The purpose of this article is to give information about the basic properties of dental zirconia implants and present 3 cases treated with two-piece zirconia implants. Two-piece zirconia dental implants, 4.0 mm diameter and 11.5 mm in length, were inserted into maxillary incisor region. They were left for 6 months to osseointegrate. Panoramic and periapical radiographs were obtained and examined for bone-implant osseointegration. During the follow-up period the patients were satisfied with their prosthesis and no complication was observed. PMID:25106014

Banko?lu Güngör, Merve; Ayd?n, Cemal; Y?lmaz, Handan; Gül, Esma Ba?ak

2014-08-01

292

Epidemiology and Risk Factors of Tooth Loss among Iranian Adults: Findings from a Large Community-Based Study  

PubMed Central

Objectives. To investigate the prevalence of tooth loss and different prosthetic rehabilitations among Iranian adults, as well as the potential determinants of tooth loss. Methods. In a cross-sectional community-based study conducted among 8094 Iranian adults living in Isfahan province, a self-administered questionnaire was used to assess epidemiologic features of tooth loss. Results. Thirty-two percent of subjects had all their teeth, 58.6% had lost less than 6, and 7.2% of participants had lost more than 6 teeth. One hundred and sixty-nine individuals (2.2%) were edentulous. Among participants, 2.3% had single jaw removable partial denture, 3.6% had complete removable denture in both jaws, and 4.6% had fixed prosthesis. Others reported no prosthetic rehabilitation (89.5%). In the age subgroup analysis (?35 and >35 years old) tooth loss was more prevalent among men than women (OR = 2.8 and 1.9, resp., P < 0.01). Also, in both age groups, current and former smokers had higher levels of tooth loss than nonsmokers (P < 0.001 and P < 0.05, resp.). In addition, tooth loss was positively related to metabolic abnormality for age group >35 years (adjusted OR = 1.29, P < 0.01). Conclusions. Tooth loss is highly prevalent in Iranian adult population. Community programs promoting oral health for prevention of tooth loss should be considered taking into account its major determinants including lower educational level, male gender, smoking, and metabolic abnormality. PMID:24228259

Keshteli, A. H.; Feizi, Awat; Savabi, Omid; Adibi, Peyman

2013-01-01

293

Noncontact intraoral measurement of force-related tooth mobility.  

PubMed

The aim of this pilot study was to measure force-related tooth mobility. Vertical and horizontal anterior tooth mobility in 31 healthy periodontal subjects was measured by a noncontact optical measurement technique. The subjects continuously increased the force on each tooth by biting on a load cell. An automated software program recorded tooth displacement at 9-N intervals. Vertical and horizontal displacements were subsequently measured. The vector of tooth mobility in the buccal direction was calculated using the Pythagorean theorem. The average displacements over all subjects for each tooth were determined. Global differences were assessed with the Wilcoxon test. There were no significant differences between contralateral teeth overall load stages. There were no significant differences in tooth mobility between the central and lateral incisors except for in the horizontal direction. However, there were significant differences between central incisor and canine and lateral incisor and canine teeth. PMID:19795136

Göllner, Matthias; Holst, Alexandra; Berthold, Christine; Schmitt, Johannes; Wichmann, Manfred; Holst, Stefan

2010-10-01

294

Hydrogen Implants for Layer Exfoliation  

NASA Astrophysics Data System (ADS)

Researchers at Corning Incorporated have developed a process whereby single crystal silicon thin films are transferred onto a flat panel display glass substrate using hydrogen ion implantation. The energy of the implant controls the effective exfoliation thickness, agreeing well with SRIM calculations, while the hydrogen ion dose controls the size of the platelets formed. The ion dose was found to influence the final void defect count in exfoliated films. Finally, the ion beam and ion implant end-station cooling characteristics were investigated. These parameters control the effective implant heat load generated during ion beam processing. The temperature at which exfoliation occurs during an exfoliation heat cycle was found to be inversely proportional to the hydrogen ion dose when the temperature during ion implantation is <100 °C. The most sensitive exfoliation temperature to ion dose dependence was observed for cooler implants, i.e. <35 °C. Data indicates that at the minimum exfoliation dose the exfoliation temperature is reduced significantly by increasing the implant heat generated during ion beam processing. Higher hydrogen doses than the minimum required for exfoliation exhibit only a small exfoliation temperature variation with ion dose. By optimizing the implant heat load generated during ion beam processing it is observed that the efficiency of the exfoliation process is also enhanced. Implant temperatures of 150 to 160 °C were found to further reduce the minimum implant dose required for exfoliation by an additional 5%, as verified by calorimetric measurements. These results enable us to further conclude that hydrogen out-diffusion is not significant in this process.

Cherekdjian, S.; Couillard, J. G.; Wilcox, C.

2011-01-01

295

Ion Implant  

NSDL National Science Digital Library

This website includes an animation which illustrates the ion implant process. Objective: Name the three common dopants used in implantation processes and explain the process of generating an ion beam from source to wafer. You can find this animation under the heading "Process & Equipment III." This simulation is from Module 026 of the Process & Equipment III Cluster of the MATEC Module Library (MML). To view other clusters or for more information about the MML visit http://matec.org/ps/library3/process_I.shtmlKey

2012-10-04

296

Implantation of INTERTAN™ nail in four patients with intertrochanteric fractures leading to single or comminute fractures: pitfalls and recommendations: a case series  

PubMed Central

Introduction Intraoperative technical complications are occasionally encountered while implanting INTERTAN™ nails for intertrochanteric fractures. Surgeons need to pay attention to the difficulties they may encounter during the implantation of an INTERTAN™ nail. Case presentation We report four cases with intraoperative difficulties during the implantation of INTERTAN™ nails among Han Chinese patients from mainland China. In Case 1, during the operation on a 75-year-old woman, an anatomical specificity of excessive femoral shaft curvation at the coronal and sagittal planes was observed; a relatively smooth implantation was achieved by adjusting the entry point. In Case 2, due to fat obstruction, an INTERTAN™ nail was implanted at an oblique angle in 64-year-old obese woman, which resulted in an iatrogenic fracture of the proximal femur. In Case 3, an iatrogenic fracture of the distal femur developed in an 83-year-old woman because of violent hammering and underestimating of bone fragility. In Case 4, an iatrogenic fracture occurred in a 40-year-old woman around the distal locking slot during the drilling process. Conclusions Preoperative evaluation should be considered as an important preparation for the implantation of an INTERTAN™ nail. Full-length anteroposterior and lateral radiographs of the injured femur are necessary to confirm the anatomical specificity. The vertical trajectory as well as sufficient reaming is important in reducing the possibility of iatrogenic fractures, particularly for obese patients. In older patients, violent hammering should be avoided and full reaming is recommended even if the canal seems to be wide enough. For cases where hard fracture reduction is predicted, the strategy of open reduction and fixation with a dynamic hip screw seems to be more rational and should be considered as an alternative method. PMID:25416923

2014-01-01

297

Multidisciplinary treatment approach for enhancement of implant esthetics.  

PubMed

A "team approach" that includes different specialties from the initial stages of implant treatment is important to achieve predictable and esthetically pleasing outcomes in compromised dental replacement cases. This report describes a severely compromised case that was properly managed by the combined efforts of a team of specialists. Briefly, prior to tooth extraction, orthodontic forced eruption was applied to coronally displace the attachment apparatus (i.e., hard and soft tissues). Then, atraumatic tooth extraction together with immediate implant placement was performed. The "sandwich bone augmentation" technique was used to augment the deficient buccal alveolar ridge. A second stage surgery was performed 6 months after healing, revealing 100% of bone fill/augmentation. This technique allowed fabrication of a final restoration that respected the proportions of the natural dentition in a case that would otherwise result in a poor esthetic outcome. PMID:15764941

Wang, Hom-Lay; Shotwell, Jeffrey L; Itose, Tatsumasa; Neiva, Rodrigo F

2005-03-01

298

A comparison of single-suture and double-suture incision closures in seaward-migrating juvenile Chinook salmon implanted with acoustic transmitters: implications for research in river basins containing hydropower structures  

SciTech Connect

Reductions in the size of acoustic transmitters implanted in migrating juvenile salmonids have resulted in the ability to make shorter incisions that may warrant using only a single suture for closure. However, it is not known if one suture will sufficiently hold the incision closed, particularly when outward pressure is placed on the surgical site such as when migrating fish experience pressure changes associated with passage at hydroelectric dams. The objective of this research was to evaluate the effectiveness of single-suture incision closures on juvenile Chinook salmon (Oncorhynchus tshawytscha). Juvenile Chinook salmon were surgically implanted with a 2012 Juvenile Salmon Acoustic Telemetry System (JSATS) transmitter (0.30 g) and a passive integrated transponder tag (0.10 g) and incisions were closed with either one suture or two sutures. Mortality and tag retention were monitored and fish were examined after 7 and 14 days to evaluate tissue responses. In a separate experiment, surgically implanted fish were exposed to simulated turbine passage and then examined for expulsion of transmitters, expulsion of viscera through the incision, and mortal injury. With incisions closed using a single suture, there was no mortality or tag loss and similar or reduced tissue reaction compared to incisions closed with two sutures. Further, surgery time was significantly reduced when one suture was used, which leads to less handling and reduced stress. No tags were expelled during pressure scenarios and expulsion of viscera only occurred in two non-mortally injured fish (5%) with single sutures that were also exposed to very high pressure changes. No viscera expulsion was present in fish exposed to pressure scenarios likely representative of hydroturbine passage at many Columbia River dams (e.g. <2.7 ratio of pressure change; an acclimation pressure of 146.2 absolute kpa and a lowest exposure pressure of ~ 53.3 absolute kpa). Based on these results, we recommend the use of a single suture for surgical implantation of transmitters with incisions that are approximately 5 1/2 mm long after tag insertion.

Brown, Richard S.; Deters, Katherine A.; Cook, Katrina V.; Eppard, M. B.

2013-07-15

299

Patient-specific Analysis of Periodontal and Peri-implant Microbiomes  

PubMed Central

Periodontally involved teeth have been implicated as ‘microbial reservoirs’ in the etiology of peri-implant diseases. Therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the degree of congruence between adjacent peri-implant and periodontal microbiomes in states of health and disease. Subgingival and peri-implant biofilm samples were collected from 81 partially edentulous individuals with periodontal and peri-implant health and disease. Bacterial DNA was isolated, and the 16S rRNA gene was amplified and sequenced by pyrotag sequencing. Chimera-depleted sequences were compared against a locally hosted curated database for bacterial identification. Statistical significance was determined by paired Student’s t tests between tooth-implant pairs. The 1.9 million sequences identified represented 523 species. Sixty percent of individuals shared less than 50% of all species between their periodontal and peri-implant biofilms, and 85% of individuals shared less than 8% of abundant species between tooth and implant. Additionally, the periodontal microbiome demonstrated significantly higher diversity than the implant, and distinct bacterial lineages were associated with health and disease in each ecosystem. Analysis of our data suggests that simple geographic proximity is not a sufficient determinant of colonization of topographically distinct niches, and that the peri-implant and periodontal microbiomes represent microbiologically distinct ecosystems. PMID:24158341

Dabdoub, S.M.; Tsigarida, A.A.; Kumar, P.S.

2013-01-01

300

Finite element simulation of bone remodelling in the human mandible surrounding dental implant  

Microsoft Academic Search

Dental implant is a biocompatible titanium device surgically placed into the jaw bone to support a prosthetic tooth crown\\u000a in order to replace missing teeth. However, placement of an implant changes the normal mechanical environment of jawbone,\\u000a which causes the bone density to redistribute and adapt to the new environment by remodelling. This study aims to predict\\u000a the density distribution

Zhiqiang Lian; Hong Guan; Saso Ivanovski; Yew-Chaye Loo; Newell Johnson; Hongwu Zhang

2011-01-01

301

Non-linear numerical analysis of a double-threaded titanium alloy dental implant by FEM  

Microsoft Academic Search

The aim of this work is to study the performance of a double-threaded variable pitch titanium alloy dental implant in a maxillary molar tooth after an implantology treatment by the finite elements method (FEM). The study employed three-dimensional finite elements modelling in order to simulate typical occlusal loads. The three-dimensional basic design of the dental implant, consisting of a dental

F. J. De Cos Juez; F. Sánchez Lasheras; P. J. García Nieto; A. Álvarez-arenal

2008-01-01

302

Contour changes in human alveolar bone following tooth extraction of the maxillary central incisor  

PubMed Central

The purpose of this study was to apply cone-beam computed tomography (CBCT) to observe contour changes in human alveolar bone after tooth extraction of the maxillary central incisor and to provide original morphological evidence for aesthetic implant treatment in the maxillary anterior area. Forty patients were recruited into the study. Each patient had two CBCT scans (CBCT I and CBCT II), one taken before and one taken three months after tooth extraction of maxillary central incisor (test tooth T). A fixed anatomic reference point was used to orient the starting axial slice of the two scans. On three CBCT I axial slices, which represented the deep, middle, and shallow layers of the socket, labial and palatal alveolar bone widths of T were measured. The number of sagittal slices from the start point to the pulp centre of T was recorded. On three CBCT II axial slices, the pulp centres of extracted T were oriented according to the number of moved sagittal slices recorded in CBCT I. Labial and palatal alveolar bone widths at the oriented sites were measured. On the CBCT I axial slice which represented the middle layer of the socket, sagittal slices were reconstructed. Relevant distances of T on the sagittal slice were measured, as were the alveolar bone width and tooth length of the opposite central incisor. On the CBCT II axial slice, which represented the middle layer of the socket, relevant distances recorded in CBCT I were transferred on the sagittal slice. The height reduction of alveolar bone on labial and palatal sides was measured, as were the alveolar bone width and tooth length of the opposite central incisor at the oriented site. Intraobserver reliability assessed by intraclass correlation coefficients (ICCs) was high. Paired sample t-tests were performed. The alveolar bone width and tooth length of the opposite central incisor showed no statistical differences (P<0.05). The labial alveolar bone widths of T at the deep, middle, and shallow layers all showed statistical differences. However, no palatal alveolar bone widths showed any statistical differences. The width reduction of alveolar bone was 1.2, 1.6, and 2.7 mm at the deep, middle, and shallow layers, respectively. The height reduction of alveolar bone on labial and palatal sides of T both showed statistical differences, which was 1.9 and 1.1 mm, respectively. PMID:25471836

Li, Bei; Wang, Yao

2014-01-01

303

Stem cells and tooth tissue engineering  

Microsoft Academic Search

The notion that teeth contain stem cells is based on the well-known repairing ability of dentin after injury. Dental stem\\u000a cells have been isolated according to their anatomical locations, colony-forming ability, expression of stem cell markers,\\u000a and regeneration of pulp\\/dentin structures in vivo. These dental-derived stem cells are currently under increasing investigation\\u000a as sources for tooth regeneration and repair. Further

Amanda H.-H. Yen; Paul T. Sharpe

2008-01-01

304

Bivalent histone modifications during tooth development.  

PubMed

Histone methylation is one of the most widely studied post-transcriptional modifications. It is thought to be an important epigenetic event that is closely associated with cell fate determination and differentiation. To explore the spatiotemporal expression of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) epigenetic marks and methylation or demethylation transferases in tooth organ development, we measured the expression of SET7, EZH2, KDM5B and JMJD3 via immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis in the first molar of BALB/c mice embryos at E13.5, E15.5, E17.5, P0 and P3, respectively. We also measured the expression of H3K4me3 and H3K27me3 with immunofluorescence staining. During murine tooth germ development, methylation or demethylation transferases were expressed in a spatial-temporal manner. The bivalent modification characterized by H3K4me3 and H3K27me3 can be found during the tooth germ development, as shown by immunofluorescence. The expression of SET7, EZH2 as methylation transferases and KDM5B and JMJD3 as demethylation transferases indicated accordingly with the expression of H3K4me3 and H3K27me3 respectively to some extent. The bivalent histone may play a critical role in tooth organ development via the regulation of cell differentiation. PMID:25394593

Zheng, Li-Wei; Zhang, Bin-Peng; Xu, Ruo-Shi; Xu, Xin; Ye, Ling; Zhou, Xue-Dong

2014-12-01

305

Restoration of the root canal treated tooth.  

PubMed

When considering endodontically treated teeth, the quality of the restoration is important from the outset. It sheds light into possible causes of pulp necrosis or failure of endodontic treatment and influences the outcome of future endodontic treatment. A tooth undergoing endodontic treatment requires an effective coronal seal during and following completion of endodontic treatment. This paper discusses, using the available literature, the maintenance of optimal coronal seal and coronal integrity during and after root canal treatment. PMID:25613259

Eliyas, S; Jalili, J; Martin, N

2015-01-23

306

Treatment options of untreatable traumatized anterior maxillary teeth for future use of dental implantation.  

PubMed

The anterior maxilla is the most traumatized region during childhood. Posttraumatic complications occasionally lead to tooth loss as well as the need for future implants. Unfortunately, it is contraindicated to place dental implants during childhood. A waiting period of approximately 8 to 10 years before completion of growth is required. For this patient to become a candidate for future dental implants, it is necessary to ensure the continuous growth and to preserve the dimensions of the alveolar process until growth has ceased from time of injury until joint maturation. To achieve these goals, it is essential to coordinate the treatment sequence at the time of trauma. After loss of a traumatized anterior permanent maxillary incisor in young adults, treatment options are limited: orthodontic closure of the gap and reshaping the adjacent teeth, or tooth extraction and maintaining the gap with a temporary restoration. Orthodontic space closure has limited indications and requires prosthetic restoration of at least 2 teeth. Extraction and temporary restoration will usually lead to bone augmentation before implantation. Other possible treatment options include orthodontic extrusion of the root remnant (in cases of untreatable root fracture or complicated crown-root fracture) and a temporary crown to serve the patient until the completion of growth and development, autogenous tooth transplantation, intentional extraction and immediate tooth replantation, distraction osteogenesis, and decoronation. Because general rules do not apply, individual treatment plans are necessary. PMID:15017299

Schwartz-Arad, Devorah; Levin, Liran; Ashkenazi, Malka

2004-03-01

307

Treatment options of untreatable traumatized anterior maxillary teeth for future use of dental implantation.  

PubMed

The anterior maxilla is the most traumatized region during childhood. Posttraumatic complications occasionally lead to tooth loss as well as the need for future implants. Unfortunately, it is contraindicated to place dental implants during childhood. A waiting period of approximately 8 to 10 years before completion of growth is required. For this patient to become a candidate for future dental implants, it is necessary to ensure the continuous growth and to preserve the dimensions of the alveolar process until growth has ceased from time of injury until joint maturation. To achieve these goals, it is essential to coordinate the treatment sequence at the time of trauma. After loss of a traumatized anterior permanent maxillary incisor in young adults, treatment options are limited: orthodontic closure of the gap and reshaping the adjacent teeth, or tooth extraction and maintaining the gap with a temporary restoration. Orthdontic space closure has limited indications and requires prosthetic restoration of at least 2 teeth. Extraction and temporary restoration will usually lead to bone augmentation before implantation. Other possible treatment options include orthodontic extrusion of the root remnant (in cases of untreatable root fracture or complicated crown-root fracture) and a temporary crown to serve the patient until the completion of growth and development, autogenous tooth transplantation, intentional extraction and immediate tooth replantation, distraction osteogenesis, and decoronation. Because general rules do not apply, individual treatment plans are necessary. PMID:15179087

Schwartz-Arad, Devorah; Levin, Liran; Ashkenazi, Malka

2004-06-01

308

Group Distal Movement of Teeth using Micro-Screw–Implant Anchorage-A Case Report  

PubMed Central

This case report describes a case of orthodontic tooth movement of a 29-year-old female patient utilizing maxillary posterior edentulous area. Micro-implants were placed at buccal edentulous spaces and inter-radicular space for retraction of entire maxillary dentition. An overjet reduction of 8mm and good posterior occlusion were achieved. PMID:24995260

2014-01-01

309

Efficacy of Nonthermal Atmospheric Pressure Plasma for Tooth Bleaching  

PubMed Central

The conventional light source used for tooth bleaching has the potential to cause thermal damage, and the actual role of the light source is doubtful. In this study, we evaluated bleaching efficacy, temperature, and morphological safety after tooth bleaching with nonthermal atmospheric pressure plasma. Tooth bleaching combined with plasma had improved efficacy in providing a higher level of brightness. The temperature of the pulp chamber was maintained around 37°C, indicating that the plasma does not cause any thermal damage. The morphological results of tooth bleaching with plasma did not affect mineral composition under scanning electron microscopy (SEM) observations. On the basis of these results, the application of plasma and low concentration of 15% carbamide peroxide (CP) has a high capability for effective tooth bleaching. It can be documented that plasma is a safe energe source, which has no deleterious effects on the tooth surface.

Nam, Seoul Hee; Lee, Hae June; Hong, Jin Woo; Kim, Gyoo Cheon

2015-01-01

310

Generation of spiral bevel gears with conjugate tooth surfaces and tooth contact analysis  

NASA Technical Reports Server (NTRS)

A new method for generation of spiral bevel gears is proposed. The main features of this method are as follows: (1) the gear tooth surfaces are conjugated and can transform rotation with zero transmission errors; (2) the tooth bearing contact is localized; (3) the center of the instantaneous contact ellipse moves in a plane that has a fixed orientation; (4) the contact normal performs in the process of meshing a parallel motion; (5) the motion of the contact ellipse provides improved conditions of lubrication; and (6) the gears can be manufactured by use of Gleason's equipment.

Litvin, Faydor L.; Tsung, Wei-Jiung; Lee, Hong-Tao

1987-01-01

311

Evaluation of the retention of endodontic implants.  

PubMed

The study investigated the retentive strength of endodontic implants measured by forced removal (pull-out or push-out tests) as a function of implant design and cement type. Smooth-tapered, threaded, and an innovative porous-surfaced implant were evaluated. Specimens were cemented in single-rooted human teeth with five different cements: zinc phosphate, polycarboxylate, glass ionomer, silicophosphate, or AH-26. The results indicated superior retention for the threaded and porous-surfaced implants, and stronger retention with glass-ionomer and AH-26 cements. PMID:3162990

Maniatopoulos, C; Pilliar, R M; Smith, D C

1988-04-01

312

Apexification of a replanted tooth using mineral trioxide aggregate.  

PubMed

The most important factors determining periodontal healing after replantation of an avulsed tooth are the extra oral period and the media in which the tooth is preserved before replantation. This case report describes an adequate periodontal healing of an avulsed immature tooth replanted after 20 min of extra alveolar dry time. Vitality was not regained and after disinfection of the pulp space mineral trioxide aggregate was used as the root filling. Follow-up confirmed complete healing periradicularly. PMID:16149928

Villa, Paula; Fernández, Rafael

2005-10-01

313

Indigenous hydroxyapatite coated and bioactive glass coated titanium dental implant system – Fabrication and application in humans  

PubMed Central

Background: The use of different bioactive materials as coating on dental implant to restore tooth function is a growing trend in modern Dentistry. In the present study, hydroxyapatite and the bioactive glass-coated implants were evaluated for their behavior in osseous tissue following implantation in 14 patients. Materials and Methods: Bioactive glass and hydroxyapatite formulated and prepared for coating on Ti-6Al-4V alloy. Hydroxyapatite coating was applied on the implant surface by air plasma spray technique and bioactive glass coating was applied by vitreous enameling technique. Their outcome was assessed after 6 months in vivo study in human. Results: Hydroxyapatite and bioactive glass coating materials were nontoxic and biocompatible. Uneventful healing was observed with both types of implants. Conclusion: The results showed bioactive glass is a good alternative coating material for dental implant. PMID:22028507

Mistry, Surajit; Kundu, Debabrata; Datta, Someswar; Basu, Debabrata; Soundrapandian, Chidambaram

2011-01-01

314

Percutaneous complete repair of failed mitral valve prosthesis: simultaneous closure of mitral paravalvular leaks and transcatheter mitral valve implantation - single-centre experience.  

PubMed

Aims: Structural deterioration and paravalvular leak (PVL) are complications associated with surgically implanted prosthetic valves, historically requiring reoperation. We present our experience of complete transcatheter repair of a degenerated mitral bioprosthesis. Methods and results: From March 2012 to October 2012, we reviewed consecutive, high-risk surgical patients (n=5) who underwent transcatheter repair of a failed mitral bioprosthesis with severe paravalvular regurgitation (PVR). Manufacturer valve sizes ranged from 27 to 33 mm, regurgitation (n=1), stenosis (n=1), or both (n=3). Percutaneous transapical and transseptal access were achieved with PVL closure performed transapically. An arteriovenous rail was created for transseptal delivery of a Melody valve. All patients had successful PVL closure with no residual PVR. Valve-in-valve (ViV) implantation was successful in four patients. Overall, mean transvalvular mitral gradient was 11.2 mmHg pre-procedure which improved to 5 mmHg post-procedure. Improvement of NYHA Class ?2 was achieved in all patients (19±3 months). One patient had controlled Melody valve embolisation which required emergent surgical replacement. Inner valve diameter was 26 mm, too large for Melody valve implantation. Conclusions: Complete transcatheter repair of a degenerated mitral bioprosthesis with PVR can be performed in the high-risk patient. Accurate measurement is necessary prior to intervention, with concern for embolisation among the larger valve sizes (>31 mm). PMID:24800978

Kliger, Chad; Angulo, Rocio; Maranan, Leandro; Kumar, Robert; Jelnin, Vladimir; Kronzon, Itzhak; Fontana, Gregory P; Plestis, Konstadinos; Patel, Nirav; Perk, Gila; Ruiz, Carlos E

2014-05-01

315

Critical buccal bone dimensions along implants.  

PubMed

The buccal bone plate is a component of the alveolar process tightly related to the tooth it supports. A plethora of physiological and pathological events can induce its remodeling. Understanding this remodeling process and its extent is of major importance for the practitioner as it can affect the functional and esthetic outcome of implant surgery at the involved sites. Bone remodeling and resorption of the buccal bone plate are inevitable after tooth loss or extraction. To limit resorption, several ridge-preservation techniques of varying efficacy have been described. Bone resorption is equally found to occur upon implant placement and is thought to be a result of the surgical trauma inflicted as well as an adaptation process of the tissues to the new foreign body. Because of the implications of bone resorption on the soft-tissue levels and the general esthetic outcome, it is of primary importance for the practitioner to be able to evaluate the hard tissues and the inherent resorption risks in an effort to optimize the treatment strategies. Based on limited short-term data, the present general opinion advises the need for a 2-mm-thick buccal bone plate in order to avoid vertical bone resorption. PMID:25123763

Merheb, Joe; Quirynen, Marc; Teughels, Wim

2014-10-01

316

The study of damage produced by H-ion and He-ion implantation in Lithium tantalate crystal  

NASA Astrophysics Data System (ADS)

LiTaO3 single crystals were implanted by 100keV H-ion or He-ion. The results indicate that H-ion implantation creates a lower damage level than the He-ion implantation does, but the yield of oxygen vacancy produced by H-ion implantation is far higher than by He-ion implantation.

Pang, L. L.; Wang, Z. G.; Yao, C. F.; Sun, J. R.; Cui, M. H.; Wei, K. F.; Shen, T. L.; Sheng, Y. B.; Zhu, Y. B.; Li, Y. F.; Chang, H. L.; Wang, J.; Zhu, H. P.

2014-04-01

317

Quantification of jaw reflexes evoked by natural tooth contact in human subjects.  

PubMed

Inhibitory jaw reflexes are believed to be important for protecting the teeth and temporo-mandibular structures from damage during sudden or forceful biting or mastication. Accordingly, alterations in these reflexes are sometimes implicated in aetiologies proposed for oro-facial pain syndromes, although the association is not well-established. We now aim to develop a method for quantifying objectively inhibitory jaw reflexes evoked by natural tooth contact. In the longer term, this may provide a new approach to examining the association of altered reflexes and clinical conditions. Eighteen subjects gave their written, informed consent, and were recruited to participate in this study. They were instructed to clench their teeth together in response to visual cues. They performed two such tasks twenty times: from the jaw postural position and from a more open position with the jaws set 10mm apart. Both tasks produced a rapid rise then stabilisation in electromyographic activity in the masseter muscle. This was always interrupted by a large inhibitory reflex starting 11.1±1.5 ms (mean±SD) after tooth contact. The inhibitions produced during the second task were similar but of significantly longer duration (24.3±6.4 vs 18.4±6.5 ms, P=0.0003, paired t-test) and greater magnitude (measured as an integral of the waveform: 1577±478 vs 1279±425%.ms, P=0.007, paired t-test). Interestingly, in a minority (13%) of the tasks, a second inhibition with a longer latency (50.9±0.9 ms) was also observed. Thus reflex responses in the masseter muscle to natural tooth contact usually consist of single inhibitory periods. In this respect they are like those induced by externally applied tooth pushing although occasionally there is a second inhibition, reminiscent of that seen with externally applied tooth taps. PMID:21419390

Ainine, Salma; Mason, Andrew G; Cadden, Samuel W

2011-09-01

318

Magnesium stable isotope ecology using mammal tooth enamel.  

PubMed

Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (?(13)C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (?(44)Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (?(26)Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for ?(26)Mg, ?(13)C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that ?(26)Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this (26)Mg enrichment up the trophic chain is due to a (26)Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using ?(26)Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel ?(26)Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages. PMID:25535375

Martin, Jeremy E; Vance, Derek; Balter, Vincent

2015-01-13

319

Endoscopically assisted procedure for removal of a foreign body from the maxillary sinus and contemporary endodontic surgical treatment of the tooth  

PubMed Central

There have been reports on the migration of teeth or implants into the maxillary sinus. We know of only one report on the migration of a gutta-percha point that had been used to fill a root canal into the ethmoid sinus. We report such a case treated with an endoscopically assisted procedure for removal of the foreign body and contemporary endodontic surgical treatment of the tooth. PMID:17090337

Costa, Fabio; Robiony, Massimo; Toro, Corrado; Sembronio, Salvatore; Politi, Massimo

2006-01-01

320

Endoscopically assisted procedure for removal of a foreign body from the maxillary sinus and contemporary endodontic surgical treatment of the tooth.  

PubMed

There have been reports on the migration of teeth or implants into the maxillary sinus. We know of only one report on the migration of a gutta-percha point that had been used to fill a root canal into the ethmoid sinus. We report such a case treated with an endoscopically assisted procedure for removal of the foreign body and contemporary endodontic surgical treatment of the tooth. PMID:17090337

Costa, Fabio; Robiony, Massimo; Toro, Corrado; Sembronio, Salvatore; Politi, Massimo

2006-01-01

321

Decaborane implantation with the medium current implanter  

NASA Astrophysics Data System (ADS)

A decaborane implantation system has been developed. The maximum beam current achieved at a wafer is 30 ?A at 5 keV with the divergence less than 0.4°, which corresponds to the equivalent 500 eV-300 ?A boron monomer implantation without an energy contamination. As-implanted secondary ion mass spectroscopy (SIMS) profile of the decaborane implanted at the equivalent energy 500 eV shows the steeper and shallower profile than that of the boron implanted. The result of Rs- Xj proves the higher activation with shallower junction depth. These advantages possibly arise from the self-amorphization layer by the decaborane implantation.

Hamamoto, Nariaki; Umisedo, Sei; Nagayama, Tsutomu; Tanjyo, Masayasu; Sakai, Shigeki; Nagai, Nobuo; Aoyama, Takayuki; Nara, Yasuo

2005-08-01

322

The combination use of platelet-rich fibrin and treated dentin matrix for tooth root regeneration by cell homing.  

PubMed

Endogenous regeneration through cell homing provides an alternative approach for tissue regeneration, except cell transplantation, especially considering clinical translation. However, tooth root regeneration through cell homing remains a provocative approach in need of intensive study. Both platelet-rich fibrin (PRF) and treated dentin matrix (TDM) are warehouses of various growth factors, which can promote cell homing. We hypothesized that endogenous stem cells are able to sense biological cues from PRF membrane and TDM, and contribute to the regeneration of tooth root, including soft and hard periodontal tissues. Therefore, the biological effects of canine PRF and TDM on periodontal ligament stem cells (PDLSCs) and bone marrow mesenchymal stem cells (BMSCs) were evaluated respectively in vitro. Beagle dogs were used as orthotopic transplantation model. It was found that PRF significantly recruited and stimulated the proliferation of PDLSCs and BMSCs in vitro. Together, PRF and TDM induced cell differentiation by upregulating the mineralization-related gene expression of bone sialoprotein (BSP) and osteopotin (OPN) after 7 days coculture. In vivo, transplantation of autologous PRF and allogeneic TDM into fresh tooth extraction socket achieved successful root regeneration 3 months postsurgery, characterized by the regeneration of cementum and periodontal ligament (PDL)-like tissues with orientated fibers, indicative of functional restoration. The results suggest that tooth root connected to the alveolar bone by cementum-PDL complex can be regenerated through the implantation of PRF and TDM in a tooth socket microenvironment, probably by homing of BMSCs and PDLSCs. Furthermore, bioactive cues and inductive microenvironment are key factors for endogenous regeneration. This approach provides a tangible pathway toward clinical translation. PMID:25111570

Ji, Baohui; Sheng, Lei; Chen, Gang; Guo, Shujuan; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

2015-01-01

323

Gene Expression Profiling during Murine Tooth Development.  

PubMed

The aim of this study was to describe the expression of genes, including ameloblastin (Ambn), amelogenin X chromosome (Amelx), and enamelin (Enam) during early (pre-secretory) tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24?h intervals, starting at the 11th embryonic day (E11.5), and up to the 7th day after birth (P7). The profile search function of Spotfire software was used to select genes with similar expression profile as the enamel genes (Ambn, Amelx, and Enam). Microarray results where validated using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), and translated proteins identified by Western-blotting. In situ localization of the Ambn, Amelx, and Enam mRNAs were monitored from E12.5 to E17.5 using deoxyoligonucleotide probes. Bioinformatics analysis was used to associate biological functions with differentially expressed (DE; p???0.05) genes. Microarray results showed a total of 4362 genes including Ambn, Amelx, and Enam to be significant DE throughout the time-course. The expression of the three enamel genes was low at pre-natal stages (E11.5-P0) increasing after birth (P1-P7). Profile search lead to isolation of 87 genes with significantly similar expression to the three enamel proteins. These mRNAs were expressed in dental epithelium and epithelium derived cells. Although expression of Ambn, Amelx, and Enam were lower during early tooth development compared to secretory stages enamel proteins were detectable by Western-blotting. Bioinformatic analysis associated the 87 genes with multiple biological functions. Around 35 genes were associated with 15 transcription factors. PMID:22866057

Landin, Maria A Dos Santos Silva; Shabestari, Maziar; Babaie, Eshrat; Reseland, Janne E; Osmundsen, Harald

2012-01-01

324

Implant Bone Integration Importance in Forensic Identification.  

PubMed

Odontological identification consists of the comparison of antemortem dental information regarding a missing person with postmortem data from an unidentified corpse or human remains. Usually, the comparison concerns morphologic features that the operator chooses among all the visible characteristics because of inter-individual uniqueness; for this reason, implants can be of enormous assistance. A case concerning the recovery of a burnt oral implant, connected to a bone fragment, among 2780 charred bone fragments, suspected to have belonged to a victim of homicide, is presented to demonstrate that dental implants and their site of bone integration represent a very precious element for personal forensic identification. Because of their morphological invariability in time and because of their morphologic uniqueness, they were used as evidence to associate unidentified human charred remains to a missing person where DNA analysis failed to do so. The case illustrates the fundamental contribution, not yet described in literature, given by the clinical aspects of tooth replacement with dental implants to a forensic discipline. Clinical practitioners should therefore be aware of the great importance of their work and of dental records in a forensic identification scenario. PMID:25387697

De Angelis, Danilo; Cattaneo, Cristina

2014-11-12

325

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2012-04-01

326

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2013-04-01

327

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2010-04-01

328

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

... 2014-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2014-04-01

329

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2011-04-01

330

21 CFR 872.3900 - Posterior artificial tooth with a metal insert.  

Code of Federal Regulations, 2010 CFR

...false Posterior artificial tooth with a metal insert. 872.3900 Section 872...3900 Posterior artificial tooth with a metal insert. (a) Identification. A posterior artificial tooth with a metal insert is a porcelain device with...

2010-04-01

331

Canine tooth in hand – A rare entity  

PubMed Central

The hand plays an important role in day to day activities and is more prone for accidental injuries. Injuries to the hand are frequently associated with foreign body penetration. Many a times the foreign body is not detected at the initial visit and can later present with other complications. We present a case of canine tooth presenting as a retained foreign body in the hand following a dog bite. The article stresses the importance of looking for foreign bodies in penetrating hand injuries, even in wounds that seem to be minor in nature.

Ranganatha, B.T.; Pawan Kumar, K.M.

2014-01-01

332

Tooth buildup prior to endodontic treatment.  

PubMed

Inadequate isolation will greatly compromise routine endodontic therapy. Loss of coronal tooth structure to caries or trauma often makes adequate rubber dam isolation difficult to achieve. This article presents some techniques for placing a buildup prior to endodontic therapy. The few minutes spent placing a buildup prior to the initiation of root canal therapy are an excellent investment in time. The time spent will be repaid by the ease of placement of the rubber dam, the quality of isolation achieved, the reduced chance of losing the provisional restoration, and the increased quality of the completed endodontic treatment. PMID:1502309

Rice, R T; Jackson, C R

1992-05-01

333

Measurement of Gear Tooth Dynamic Friction  

NASA Technical Reports Server (NTRS)

Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

1996-01-01

334

Tooth cusp sharpness as a dietary correlate in great apes.  

PubMed

Mammalian molars have undergone heavy scrutiny to determine correlates between morphology and diet. Here, the relationship between one aspect of occlusal morphology, tooth cusp radius of curvature (RoC), and two broad dietary categories, folivory and frugivory, is analyzed in apes. The author hypothesizes that there is a relationship between tooth cusp RoC and diet, and that folivores have sharper teeth than frugivores, and further test the correlation between tooth cusp RoC and tooth cusp size. Eight measures of tooth cusp RoC (two RoCs per cusp) were taken from 53 M(2) s from four species and subspecies of frugivorous apes (Pongo pygmaeus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, and Gorilla gorilla gorilla) and two subspecies of folivorous apes (Gorilla beringei beringei, and Gorilla beringei graueri). Phylogenetically corrected ANOVAs were run on the full dataset and several subsets of the full dataset, revealing that, when buccolingual RoCs are taken into account, tooth cusp RoCs can successfully differentiate folivores and frugivores. PCAs revealed that folivores consistently had duller teeth than frugivores. In addition, a weak, statistically significant positive correlation exists between tooth cusp size and tooth cusp RoC. The author hypothesizes differences in tooth cusp RoC are correlated with wear rates, where, per vertical unit of wear, duller cusps will have a longer length of exposed enamel ridge than sharper cusps. More data need to be gathered to determine if the correlation between tooth cusp RoC and tooth cusp size holds true when small primates are considered. PMID:24227163

Berthaume, Michael A

2014-02-01

335

A 5-year randomized trial to compare 1 or 2 implants for implant overdentures.  

PubMed

The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P < 0.001) higher than at baseline in both groups and remained with no significant difference (P = 0.32) between the groups. No implants failed in group 1 but 5 failed before loading in 4 participants in group 2. Most participants required maintenance or occasionally denture replacement, and although differences between the groups were not statistically significant, group 1 experienced almost twice as many fractured dentures usually adjacent to the implant attachment. We conclude that there were no significant differences after 5 y in satisfaction or survival of implants with mandibular overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856). PMID:25348544

Bryant, S R; Walton, J N; MacEntee, M I

2015-01-01

336

Case presentation of florid cemento-osseous dysplasia with concomitant cemento-ossifying fibroma discovered during implant explantation.  

PubMed

A 39-year-old African American woman presented for treatment of a symptomatic mandibular right first molar with a large, periapical radiolucency. After initial attempts at endodontic therapy, this tooth was ultimately extracted owing to unabated symptoms. The extraction site underwent ridge preservation grafting, implant placement, and restoration. After 26 months of implant function, the patient returned with clinical symptoms of pain, buccal swelling, and the sensation of a "loose" implant. This case report details a diagnosis of 2 distinct disease entities associated with the implant site, a cemento-ossifying fibroma and florid cemento-osseous dysplasia of the mandible. This diagnosis was determined from clinical, surgical, radiographic, and histopathologic evidence after biopsy and removal of the previously osseointegrated implant following postinsertion failure by fibrous encapsulation. Before implant therapy, it is essential to conduct a thorough radiographic evaluation of any dental arch with suspected bony lesions to prevent implant failure. PMID:22858018

Gerlach, Robert C; Dixon, Douglas R; Goksel, Tamer; Castle, James T; Henry, Walter A

2013-03-01

337

Forced orthodontic eruption for augmentation of soft and hard tissue prior to implant placement.  

PubMed

Forced orthodontic eruption (FOE) is a non-surgical treatment option that allows modifying the osseous and gingival topography. The aim of this article is to present a clinical case of a FOE, which resulted in an improvement of the amount of available bone and soft-tissues for implant site development. Patient was referred for treatment of mobility and unesthetic appearance of their maxillary incisors. Clinical and radiographic examination revealed inflamed gingival tissue, horizontal and vertical tooth mobility and interproximal angular bone defects. It was chosen a multidisciplinary treatment approach using FOE, tooth extraction, and immediate implant placement to achieve better esthetic results. The use of FOE, in periodontally compromised teeth, promoted the formation of a new bone and soft-tissue in a coronal direction, without additional surgical procedures, enabling an esthetic, and functional implant-supported restoration. PMID:24015019

de Molon, Rafael Scaf; de Avila, Erica Dorigatti; de Souza, João Antonio Chaves; Nogueira, Andressa Vilas Boas; Cirelli, Carolina Chan; Margonar, Rogerio; Cirelli, Joni Augusto

2013-04-01

338

Forced orthodontic eruption for augmentation of soft and hard tissue prior to implant placement  

PubMed Central

Forced orthodontic eruption (FOE) is a non-surgical treatment option that allows modifying the osseous and gingival topography. The aim of this article is to present a clinical case of a FOE, which resulted in an improvement of the amount of available bone and soft-tissues for implant site development. Patient was referred for treatment of mobility and unesthetic appearance of their maxillary incisors. Clinical and radiographic examination revealed inflamed gingival tissue, horizontal and vertical tooth mobility and interproximal angular bone defects. It was chosen a multidisciplinary treatment approach using FOE, tooth extraction, and immediate implant placement to achieve better esthetic results. The use of FOE, in periodontally compromised teeth, promoted the formation of a new bone and soft-tissue in a coronal direction, without additional surgical procedures, enabling an esthetic, and functional implant-supported restoration. PMID:24015019

de Molon, Rafael Scaf; de Avila, Érica Dorigatti; de Souza, João Antonio Chaves; Nogueira, Andressa Vilas Boas; Cirelli, Carolina Chan; Margonar, Rogerio; Cirelli, Joni Augusto

2013-01-01

339

Decaborane implantation with the medium current implanter  

Microsoft Academic Search

A decaborane implantation system has been developed. The maximum beam current achieved at a wafer is 30?A at 5keV with the divergence less than 0.4°, which corresponds to the equivalent 500eV–300?A boron monomer implantation without an energy contamination. As-implanted secondary ion mass spectroscopy (SIMS) profile of the decaborane implanted at the equivalent energy 500eV shows the steeper and shallower profile

Nariaki Hamamoto; Sei Umisedo; Tsutomu Nagayama; Masayasu Tanjyo; Shigeki Sakai; Nobuo Nagai; Takayuki Aoyama; Yasuo Nara

2005-01-01

340

On the Gap-Tooth direct simulation Monte Carlo method  

E-print Network

This thesis develops and evaluates Gap-tooth DSMC (GT-DSMC), a direct Monte Carlo simulation procedure for dilute gases combined with the Gap-tooth method of Gear, Li, and Kevrekidis. The latter was proposed as a means of ...

Armour, Jessica D

2012-01-01

341

Inhibition of Tooth Eruption in the Rat by a Bisphosphonate  

Microsoft Academic Search

Studies of osteopetrotic rodents suggest that localized alveolar bone resorption must occur if the tooth is to To test this hypothesis directly, we injected postnatal rats with pamidronate, a bisphosphonate that reduces bone resorption by osteoclasts, The results of these experiments demonstrate that this bisphosphonate inhibits the time of tooth of both rat molars and incisors. Pamidronate does not inhibit

R. L. Grier; G. E. Wise

1998-01-01

342

Terfenol-D tooth phone performance characterization and optimization  

Microsoft Academic Search

A Terfenol-D transducer has been developed for use as a tooth phone with both sensing and actuating capabilities by Audiodontics, Inc. This research focuses on characterizing the sensitivity of the tooth phone's magnetostrictive Terfenol-D rod performance in both sensor and actuator modes to changes in the initial prestress of the device. A test apparatus was designed to allow prestress variability

Mark E. Staley; Alison B. Flatau

2005-01-01

343

Optimize design dexterity of tooth-arrangement three-fingered hands  

NASA Astrophysics Data System (ADS)

"Tooth-arrangement Three-fingered Hands" is a brand-new oral cavity repairing robot. It has the functions of fine grasping and arranging artificial tooth, manufacturing complete denture, etc. A new optimization design method is proposed in this paper that solves the problems in optimization structure parameter confirming and optimal dexterous design. The bionic theorem behind duplicating the dexterity of the human finger is incorporated into the structure parameter optimization algorithm. Through analyzing the dexterity of the single finger, adopting the design criteria of dexterous degree with optimum index and combining the characteristic of grasping the smallest object, this design method can confirm the best dexterity area for single finger, relations between every rod length and rotation range of every joint. Using MATLAB optimization toolbox to optimize above-mentioned structure parameter, it gains the optimal dimension that meets characteristic of human fingers and can finish grasping. A quantitative method is also proposed in this paper to calculate the relative position between fingers. It is applied to the real design of Tooth-Arrangement Three-fingered Hands and obtained optimal flexible performance.

Wang, Hai-ying; Zhang, Li-yong; Zhang, Yong-de

2005-12-01

344

Patients' knowledge and awareness of dental implants in a Turkish subpopulation  

PubMed Central

PURPOSE The purpose of this study was to evaluate the patients' knowledge on dental implants in a Turkish subpopulation. MATERIALS AND METHODS Five hundred twenty seven Turkish adults referred to Yeditepe University Faculty of Dentistry, Istanbul, Turkey, were presented with a questionnaire including 20 questions regarding the level of information and awareness about the dental implants. The data were collected and statistical analyses were performed with Chi square test to compare the descriptive data. RESULTS Among 527 subjects, 54% were female and 46% were male with a mean age of 42.2 years. The rate of patients' implant awareness was 27.7%. When the patients were questioned about the treatment options for rehabilitation of tooth missing, 60.9% of patients were informed about fixed partial denture, followed by conventional complete denture (32.5%) and removable partial denture (24.9%). Six percent reported that they were very well informed about the dental implants whereas 48.2% were poorly informed. The information sources of the implants were from the dentist (44.5%), printed media (31.6%) and friends and acquaintances (17.3%), respectively. Sixteen percent of the population believed that their implants would last forever. CONCLUSION The dentists should give more detailed information to the patients about dental implants and tooth-supported fixed partial dentures in the future. PMID:24843399

Özçak?r Tomruk, Ceyda; ?ençift, Kemal

2014-01-01

345

[Comperative study of implant surface characteristics].  

PubMed

The osseointegration between the implant and its' bone environment is very important. The implants shall meet the following requirements: biocompatibility, rigidity, resistance against corrosion and technical producibility. In our present study surface morphology and material characteristics of different implants (Denti Bone Level, Denti Zirconium C, Bionika CorticaL, Straumann SLA, Straumann SLA Active, Dentsply Ankylos and Biotech Kontact implant) were investigated with scanning electron microscopy and energy-dispersive X-ray spectroscopy. The possible surface alterations caused by the manufacturing technology were also investigated. During grit-blasting the implants' surface is blasted with hard ceramic particles (titanium oxide, alumina, calcium phosphate). Properties of blasting material are critical because the osseointegration of dental implants should not be hampered. The physical and chemical features of blasting particles could importantly affect the produced surfaces of implants. Titanium surfaces with micro pits are created after immersion in mixtures of strong acids. On surfaces after dual acid-etching procedures the crosslinking between fibrin and osteogenetic cells could be enhanced therefore bone formation could be directly facilitated on the surface of the implant. Nowadays there are a number of surface modification techniques available. These can be used as a single method or in combination with each other. The effect of the two most commonly used surface modifications (acid-etching and grit-blasting) on different implants are demonstrated in our investigation. PMID:24551957

Katona, Bernadett; Daróczi, Lajos; Jenei, Attila; Bakó, József; Hegedus, Csaba

2013-12-01

346

Terfenol-D tooth phone performance characterization and optimization  

NASA Astrophysics Data System (ADS)

A Terfenol-D transducer has been developed for use as a tooth phone with both sensing and actuating capabilities by Audiodontics, Inc. This research focuses on characterizing the sensitivity of the tooth phone's magnetostrictive Terfenol-D rod performance in both sensor and actuator modes to changes in the initial prestress of the device. A test apparatus was designed to allow prestress variability while operating the transducer as either a sensor or an actuator. To assess the sensor-mode performance, a force-feedback loop control system was used to excite the tooth phone with a constant force from a mechanical shaker at the tooth-tooth phone interface surface while measuring the voltage generated in the transducer's coil. The shaker was driven with a 200Hzto7kHz swept sine at various dynamics force loadings for prestresses ranging from 0.25to3.5ksi. The results indicate a prestress of 2ksi offers the best sensor-mode performance. To assess the actuator performance, a accelerometer was attached to the tooth-tooth phone interface surface and output acceleration was recorded while sweeping the tooth phone excitation frequency from 200Hzto7kHz with zero-to-peak voltages of 0.1, 0.3, and 0.5V. The prestress settings were varied from 0.3to3.25ksi. As an actuator, no prestress offered a significant broadband performance advantage. Finally, comparisons were made of the tooth phone and an accelerometer for measuring tooth vibrations induced during humming. They perform similarly and capture much of the frequency content found in concurrently recorded microphone data.

Staley, Mark E.; Flatau, Alison B.

2005-05-01

347

Autocrine and paracrine Shh signaling are necessary for tooth morphogenesis, but not tooth replacement in snakes and lizards (Squamata)  

Microsoft Academic Search

Here we study the role of Shh signaling in tooth morphogenesis and successional tooth initiation in snakes and lizards (Squamata). By characterizing the expression of Shh pathway receptor Ptc1 in the developing dentitions of three species (Eublepharis macularius, Python regius, and Pogona vitticeps) and by performing gain- and loss-of-function experiments, we demonstrate that Shh signaling is active in the squamate

Gregory R. Handrigan; Joy M. Richman

2010-01-01

348

Microbial diversity of peri-implant biofilms on implant fixed bar and telescopic double crown attachments.  

PubMed

One of the principal problems in oral implantation is inflammation of peri-implant hard and soft tissues caused by bacterial biofilms. The purpose of the present study was to evaluate the microbial diversity of peri-implant biofilms on 2 different implant-anchored attachment types in vivo. Samples of peri-implant sulcus fluid were collected from 8 patients with implant-supported bar attachments and 8 patients with implant-anchored telescopic double crown attachments. Samples of sulcus fluid of the adjacent teeth were also collected from the partially edentulous patients with implant fixed telescopic double crowns. The mixed amplicons of 16S rRNA fragments of different bacterial origins were separated by use of single-strand conformation polymorphism analysis to identify the predominant bacterial genera. With 3.5 ± 2.1 different predominant bacterial genera in the sulcus fluid surrounding implant-supported bar attachments and 6.3 ± 3.1 different predominant genera in the sulcular fluid of implant-anchored double crown attachments, the differences were not statistically significant (P = .11). The microbial diversity in the sulcus fluid surrounding the remaining dentition was similar to that of the implant fixed telescopic attachments (6.3 ± 2.1). Aside from host response and other individual factors, the microbial diversity of peri-implant biofilms seems to be impaired by cofactors such as the possibility of cleaning the implant-supported supraconstructions and the different plaque-retaining sites. Nevertheless, these differences do not lead to statistically significant differences in the microbial diversity of peri-implant plaques. PMID:21332328

Heuer, Wieland; Kettenring, Andreas; Demling, Anton; Stumpp, Sascha Nico; Gellermann, Eva; Winkel, Andreas; Stiesch, Meike

2013-12-01

349

p38? MAPK Is Required for Tooth Morphogenesis and Enamel Secretion.  

PubMed

An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678-27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38? MAPK in ectodermal appendages using K14-cre mice (p38?(K14) mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38?, expression of amelogenin and ?4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38? in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38? functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38? MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel. PMID:25406311

Greenblatt, Matthew B; Kim, Jung-Min; Oh, Hwanhee; Park, Kwang Hwan; Choo, Min-Kyung; Sano, Yasuyo; Tye, Coralee E; Skobe, Ziedonis; Davis, Roger J; Park, Jin Mo; Bei, Marianna; Glimcher, Laurie H; Shim, Jae-Hyuck

2015-01-01

350

Retrograde peri-implantitis  

PubMed Central

Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to) retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation. PMID:20922082

Mohamed, Jumshad B.; Shivakumar, B.; Sudarsan, Sabitha; Arun, K. V.; Kumar, T. S. S.

2010-01-01

351

Ganciclovir implants (Vitrasert).  

PubMed

Ganciclovir implants, used for treating CMV retinitis, are effective in stemming the progression of CMV in patients already diagnosed with the disease. The implants need to be replaced after 32 weeks to lessen the likelihood of relapse. Studies show ganciclovir implants improve eyesight in the majority of patients using them. One large trial, comparing implants with other ganciclovir delivery methods, shows implants to be superior in halting CMV progression. A drawback of the implants is that because they release the drug into the eye only, CMV can spread to other parts of the body. A pill form of the drug is available to use in combination with the implant. PMID:11363393

1996-04-01

352

Unconventional Implant Placement IV. Implant Placement through Impacted Teeth to Avoid Invasive Surgery. Long-term Results of 3 Cases  

PubMed Central

This paper presents the long-term data of patients that have been treated with an unconventional implant placement protocol to avoid an invasive surgery when edentulism was caused by an impacted tooth. In 2009, the follow-up of this unconven-tional protocol was 2 to 3.5 years; this article documents now the long-term 5- to 8-year follow-up of 3 patients and 5 im-plants. Over this period of time, implant stability was maintained without complications. This unconventional protocol opens intriguing possibilities; however, more patients with long-term follow-up are warranted before endorsing it in routine appli-cation. Nonetheless, it might suggest that there is still room to revisit one of the leading concepts in dental implantology. PMID:25674167

Mithridade, Davarpanah; Serge, Szmukler-Moncler; Keyvan, Davarpanah; Nedjoua, Capelle-Ouadah; Georgy, Demurashvili; Philippe, Rajzbaum

2015-01-01

353

Management of interproximal soft tissue with a resin-bonded prosthesis after immediate implant placement: a clinical report.  

PubMed

This report describes immediate implant placement after the extraction of a vertically fractured tooth. During the healing phase, a resin-bonded prosthesis was inserted as a provisional restoration. After the creation of the optimal emergence profile and papillae with the provisional restoration, the definitive metal ceramic crown was fabricated. PMID:22230910

Ozdemir, Erdem; Lin, Wei-Shao; Erkut, Selim

2012-01-01

354

Diagnosis of Charcot-Marie-Tooth Disease  

PubMed Central

Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy (HMSN) is a genetically heterogeneous group of conditions that affect the peripheral nervous system. The disease is characterized by degeneration or abnormal development of peripheral nerves and exhibits a range of patterns of genetic transmission. In the majority of cases, CMT first appears in infancy, and its manifestations include clumsiness of gait, predominantly distal muscular atrophy of the limbs, and deformity of the feet in the form of foot drop. It can be classified according to the pattern of transmission (autosomal dominant, autosomal recessive, or X linked), according to electrophysiological findings (demyelinating or axonal), or according to the causative mutant gene. The classification of CMT is complex and undergoes constant revision as new genes and mutations are discovered. In this paper, we review the most efficient diagnostic algorithms for the molecular diagnosis of CMT, which are based on clinical and electrophysiological data. PMID:19826499

Banchs, Isabel; Casasnovas, Carlos; Albertí, Antonia; De Jorge, Laura; Povedano, Mónica; Montero, Jordi; Martínez-Matos, Juan Antonio; Volpini, Victor

2009-01-01

355

The design and production of Ti-6Al-4V ELI customized dental implants  

NASA Astrophysics Data System (ADS)

This paper addresses the production of customized Ti-6Al-4V ELI dental implants via electron beam melting (EBM). The melting of Ti-6Al-4V ELI powder produces implants with great biocompatibility, fi ne mechanical performance, and a high bone ingrowth potential. The EBM technology is used to produce one-component dental implants that mimic the exact shape of the patient’s tooth, replacing the traditional, three-component, “screw-like” standardized dental implants currently used. The new generation of implants provides the possibility of simplifying pre-insertion procedures leading to faster healing time, and the potential of better and stronger osseointegration, specifi cally through incorporating lattice structure design.

Chahine, Gilbert; Koike, Mari; Okabe, Toru; Smith, Pauline; Kovacevic, Radovan

2008-11-01

356

Investigating tooth loss and associated factors among older Taiwanese adults.  

PubMed

The aim of this study was to evaluate factors associated with tooth loss in older Taiwanese adults with different numbers of remaining teeth. This study evaluated oral health status and tooth loss among 2286 adults aged over 65. Subjects were classified according to number of teeth (Group 1 <20 teeth vs. Group 2 ?20 teeth). Tooth loss and oral health data were collected from the National Health Interview Survey (NHIS), compared between groups and analyzed by multivariate modeling. Group 1 subjects were older and had more partial dentures. Tooth loss was associated with self-limited food choices due to oral health status, and malnutrition. Tooth loss in Group 2 subjects was significantly associated with lower mental status. Tooth loss may predict cognitive status (odds ratio (OR) 1.30) and physical-disability (OR 1.79). Our results suggested that tooth loss was associated with age, more partial dentures, self-limited food choices, malnutrition, and lower mental and cognitive status and physical disability. PMID:24568967

Wang, Tze-Fang; Chen, Ying-Yu; Liou, Yiing-Mei; Chou, Chyuan

2014-01-01

357

Surface modification of sapphire by ion implantation  

SciTech Connect

The range of microstructures and properties of sapphire (single crystalline Al{sub 2}O{sub 3}) that are produced by ion implantation are discussed with respect to the implantation parameters of ion species, fluence, irradiation temperature and the orientation of the ion beam relative to crystallographic axes. The microstructure of implanted sapphire may be crystalline with varying concentrations of defects or it may be amorphous perhaps with short-range order. At moderate to high fluences, implanted metallic ions often coalesce into pure metallic colloids and gas ions form bubbles. Many of the implanted microstructural features have been identified from studies using transmission electron microscopy (TEM), optical spectroscopy, Moessbauer spectroscopy, and Rutherford backscattering-channeling. The chemical, mechanical, and physical properties reflect the microstructures.

McHargue, C.J.

1998-11-01

358

Reasons for mini-implants failure: choosing installation site should be valued!  

PubMed Central

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that: a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants. Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows: 1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant. PMID:24945511

Consolaro, Alberto; Romano, Fábio Lourenço

2014-01-01

359

Functional constraints on tooth morphology in carnivorous mammals  

PubMed Central

Background The range of potential morphologies resulting from evolution is limited by complex interacting processes, ranging from development to function. Quantifying these interactions is important for understanding adaptation and convergent evolution. Using three-dimensional reconstructions of carnivoran and dasyuromorph tooth rows, we compared statistical models of the relationship between tooth row shape and the opposing tooth row, a static feature, as well as measures of mandibular motion during chewing (occlusion), which are kinetic features. This is a new approach to quantifying functional integration because we use measures of movement and displacement, such as the amount the mandible translates laterally during occlusion, as opposed to conventional morphological measures, such as mandible length and geometric landmarks. By sampling two distantly related groups of ecologically similar mammals, we study carnivorous mammals in general rather than a specific group of mammals. Results Statistical model comparisons demonstrate that the best performing models always include some measure of mandibular motion, indicating that functional and statistical models of tooth shape as purely a function of the opposing tooth row are too simple and that increased model complexity provides a better understanding of tooth form. The predictors of the best performing models always included the opposing tooth row shape and a relative linear measure of mandibular motion. Conclusions Our results provide quantitative support of long-standing hypotheses of tooth row shape as being influenced by mandibular motion in addition to the opposing tooth row. Additionally, this study illustrates the utility and necessity of including kinetic features in analyses of morphological integration. PMID:22899809

2012-01-01

360

Osseointegrated dental implants in growing children: a literature review.  

PubMed

Edentulism is usually associated with the aging patient. However, total or partial tooth loss also affects young individuals, mainly as a result of trauma, decay, anodontia, or congenital and acquired jaw defects involving the alveolar processes. For elderly patients, the use of oral implants has become an accepted treatment modality for edentulism, and most of today's knowledge regarding implants is based on such practice. There has been hesitation to perform implant therapy for growing children; hence, few children to date have been provided with implant-supported construction. Consequently, little is known about the outcome of the osseointegration procedure in young patients, and until now, only a limited number of case presentations have been reported. This article reviews the current literature to discuss the use of dental implants in growing patients and the influence of maxillary and mandibular skeletal and dental growth on the stability of those implants. The literature review was performed through Science Direct, Wileys Blackwell Synergy, PubMed, Google, Embase, Medknow publications, and Springer for references published from 1963 to 2011. It is recommended to wait for the completion of dental and skeletal growth, except for severe cases of ectodermal dysplasia. PMID:22214484

Mankani, Nivedita; Chowdhary, Ramesh; Patil, Brijesh A; Nagaraj, E; Madalli, Poornima

2014-10-01

361

Tooth development in a model reptile: functional and null generation teeth in the gecko Paroedura picta  

PubMed Central

This paper describes tooth development in a basal squamate, Paroedura picta. Due to its reproductive strategy, mode of development and position within the reptiles, this gecko represents an excellent model organism for the study of reptile development. Here we document the dental pattern and development of non-functional (null generation) and functional generations of teeth during embryonic development. Tooth development is followed from initiation to cytodifferentiation and ankylosis, as the tooth germs develop from bud, through cap to bell stages. The fate of the single generation of non-functional (null generation) teeth is shown to be variable, with some teeth being expelled from the oral cavity, while others are incorporated into the functional bone and teeth, or are absorbed. Fate appears to depend on the initiation site within the oral cavity, with the first null generation teeth forming before formation of the dental lamina. We show evidence for a stratum intermedium layer in the enamel epithelium of functional teeth and show that the bicuspid shape of the teeth is created by asymmetrical deposition of enamel, and not by folding of the inner dental epithelium as observed in mammals. PMID:22780101

Zahradnicek, Oldrich; Horacek, Ivan; Tucker, Abigail S

2012-01-01

362

Assessment of the effect of casein phosphopeptide-amorphous calcium phosphate on postoperative sensitivity associated with in-office vital tooth whitening.  

PubMed

The aim of this study was to evaluate the efficacy of tooth mousse containing 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in reducing tooth sensitivity associated with in-office vital tooth whitening. In-office tooth whitening was performed for 51 participants using 35% hydrogen peroxide gel in a single visit. After the procedure, each participant was randomly assigned to one of three groups: gel without desensitizing agent (n=17), gel with 2% sodium fluoride (n=17), gel with 10% CPP-ACP (n=17). A small amount of the desensitizing gel assigned for each participant was applied directly on the labial surfaces of teeth and left undisturbed for three minutes. The participants were asked to apply the gel assigned to them for three minutes twice daily after brushing their teeth, and to continue this for 14 days. The participants were asked to return for follow-up visits after 24 hours and on days 3, 7, and 14, at which time teeth shade changes were assessed by one evaluator using a value-oriented Vita classic shade guide. The incidence, duration, and intensity of tooth sensitivity experienced was self-assessed on a daily basis for the 14-day study period using a visual analog scale (VAS). The effect of the three gels on tooth sensitivity was assessed using one-way analysis of variance and a ? (2) test (?=0.05). The general linear model was used to compare intensity-level differences in the three studied groups and for shade stability over the follow-up period. The results of this study showed that all three gels decreased the intensity of sensitivity associated with tooth whitening. The intensity of sensitivity was lower in the fluoride group than in the other two groups; however, it was not statistically significant (p=0.112 and p=0.532 on day 1 and day 2, respectively). The average shade change was 6.8. None of the tested materials affected the efficacy of tooth whitening, but the shade change among the fluoride group showed more color stability than that of the other two groups. This study suggested that using a gel after tooth whitening can reduce the intensity of tooth sensitivity associated with in-office whitening procedures without affecting the efficiency of tooth whitening. However, it failed to demonstrate that using a 10% CPP-ACP could provide additional therapeutic benefits. PMID:24147745

Maghaireh, G A; Alzraikat, H; Guidoum, A

2014-01-01

363

Study of the kinematic and load sharing properties of wormgearing with non-symmetric tooth profiles  

NASA Technical Reports Server (NTRS)

The geometry of non-symmetric tooth profiles, i.e. tooth profiles with different pressure angles on the two sides of the tooth, is studied. A feasible non-symmetric tooth profile for application in helicopter transmissions is laid out as the best compromise among several conflicting factors. The non-symmetric tooth profile is then compared with the symmetric tooth profile studied previously. Based on the detailed comparisons it is concluded that the use of the non-symmetric tooth profile would severely limit the face width of the worm, consequently reduce the number of meshing teeth and cause much higher normal load on the individual gear teeth.

Sun, D. C.; Yuan, Qin

1995-01-01

364

Vertical Root Fracture: Preservation of the Alveolar Ridge Using Immediate Implants  

PubMed Central

Teeth with vertical root fracture (VRF) have complete or incomplete fractures that begin in the root and extend toward the occlusal surface. The most frequent causes of VRF originate from physical trauma, occlusal prematurity, inadequate endodontic treatment, and iatrogenic causes. Diagnose is difficult and delay can cause stomatognathic system problem. The purpose of this case report was to evaluate immediate implant placement after extraction of teeth with vertical root fracture. For the 1st case, the VRF in 1st left lower molar was confirmed during surgical flap and at the same time, the tooth was removed and immediate implant was placed. For the 2nd case, the VRF 1st left lower molar was confirmed during endodontic access and at the same appointment, the tooth was removed and the immediate implant is placed. Several studies have shown that immediate implants have similar success rates when compared with late implants. Consider that this approach is a safe procedure with favorable prognosis. In cases of VRF, the main factor to be considered is the presence of adequate bone support and immediate implants can preserve the vertical bone height, adding the fact that good patient compliance reduces the number of surgical interventions and promotes the functionality of stomatognathic system. PMID:24715996

Oya, Edmar de Oliveira; Pallos, Debora; Schwartz-Filho, Humberto Osvaldo; Brandt, William Cunha; Sendyk, Wilson Roberto; Roman-Torres, Caio Vinicius Gonçalves

2014-01-01

365

Genetics Home Reference: Charcot-Marie-Tooth disease  

MedlinePLUS

... Marie-Tooth disease affect the function of the proteins in ways that are not fully understood; however, they likely impair axons, which transmit nerve impulses, or affect the specialized cells that produce myelin. As a result, peripheral nerve ...

366

12. Interior view showing main section, mezzanine and saw tooth ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Interior view showing main section, mezzanine and saw tooth truss roof with skylight, looking west. - College Heights Lemon Packing House, 519-532 West First Street, Claremont, Los Angeles County, CA

367

Triple tooth in primary dentition: A proposed classification.  

PubMed

Triple teeth may result from fusion, gemination or concrescence causing transient esthetic and functional problems in primary dentition and retardation or alteration of development and eruption of permanent successors. We report an unusual case of a boy aged five with fusion among maxillary left primary central incisor, lateral incisor and a supernumerary tooth concomitant with agenesis of permanent lateral incisor. A review of literature on triple tooth was done along with a proposed classification of the triple teeth. PMID:24015024

Shilpa, Gaddam; Nuvvula, Sivakumar

2013-04-01

368

Rhinolithiasis due to supernumerary ectopic tooth: very rare case.  

PubMed

An ectopic supernumerary tooth causing the formation of rhinolith was never reported before in the medical literature. A 30 years old male patient presented to our hospital with one sided nasal obstruction, recurrent epistaxis, and nasal discharge. Anterior rhinoscopy, nasal endoscopy and X-ray paranasal sinuses revealed a rhinolith in the left nasal cavity. Preoperative evaluation and post operative examination of the specimen proved that the nidus of rhinolith was a supernumerary ectopic tooth. PMID:24427605

Janardhan, Nara; Kumar, S Rajesh; Reddy, R Raghavendra; Kumar, C Aruna

2013-12-01

369

Terfenol-D tooth phone performance characterization and optimization  

Microsoft Academic Search

A Terfenol-D transducer has been developed for use as a tooth phone with both sensing and actuating capabilities by Audiodontics, Inc. This research focuses on characterizing the sensitivity of the tooth phone’s magnetostrictive Terfenol-D rod performance in both sensor and actuator modes to changes in the initial prestress of the device. A test apparatus was designed to allow prestress variability

Mark E. Staley; Alison B. Flatau

2005-01-01

370

Surface topography of the cylindrical gear tooth flanks after machining  

Microsoft Academic Search

The paper presents an analysis of three-dimensional surface topography of side and side out in tooth space flanks of cylindrical\\u000a gear machined after hobbing and chiselling by Fellows method. The parameters and functions of surface topography as well as\\u000a spectral analysis were used. Primary surface topography after extraction of involute tooth profile was analysed. It was found\\u000a that contour maps

Jacek Michalski

2009-01-01

371

A conservative approach toward restoration of fractured anterior tooth  

PubMed Central

Reattachment of the fractured anterior tooth is a highly conservative and aesthetic treatment that has gained popularity in the recent past. Presented here is one such case in which a combination of external enamel bevel and internal dentinal groove has been used to enhance the bonding between the fractured fragment and the remaining tooth. The treatment was found to be successful both functionally and aesthetically at the 18-month follow-up. PMID:22629071

Goenka, Puneet; Sarawgi, Aditi; Dutta, Samir

2012-01-01

372

Correlation between implantation defects and dopants in Fe-implanted SiC  

NASA Astrophysics Data System (ADS)

SiC single crystals were implanted with Fe ions and the effects of implantation temperature, Fe concentration, and subsequent swift heavy ion irradiation on both dopant and damage depth distributions were evaluated by using RBS and channelling techniques. It is found that an increase of the implantation temperature above the threshold temperature for amorphization can lead to the formation of a broad layer (˜50 nm) containing a large concentration of implanted Fe atoms (˜2 at.%) but almost free of implantation defects. This particular configuration is likely due to dynamic annealing during implantation combined with defect annihilation at the surface. It is only observed when the implanted species concentration does not exceed a critical value (which lies between 2 and 5 at.% in the present system). Post-implantation swift heavy ion irradiation leads to a further decrease of the damage level, while the Fe distribution is not affected. The Fe substitutional fraction has been evaluated in the different tested conditions. A maximum value of ˜50% is found when implantation is performed at the temperature above that required to prevent amorphization (470 K in the present system). Swift-heavy ion irradiation seems to induce Fe atoms relocation at substitutional positions.

Declémy, A.; Debelle, A.; Dupeyrat, C.; Thomé, L.; Monnet, I.; Eyidi, D.

2012-03-01

373

Is there a link between ovarian cancer and tooth agenesis?  

PubMed

An epidemiologic study from the year 2008 found a highly significant increase of congenital tooth agenesis in women with ovarian cancer suggesting that a common genetic etiology may predispose women to both conditions. The finding was reminiscent of a previously described family harboring an AXIN2 mutation which could be shown to segregate with both the tooth agenesis and the predisposition to colon cancer transmitted in this family. Since tooth agenesis as a marker for susceptibility to ovarian cancer would be of great relevance to both oncologists and women with inborn missing teeth, the relationship between the two disorders requires a thorough assessment. We examined DNA samples from the ovarian cancer patients who participated in the original study, to look for a possible genetic connection between their ovarian malignancies and tooth agenesis. MSX1, PAX9, AXIN2, EDA, WNT10A, BARX and BRCA1 genes were selected for sequence analysis as they may cause tooth agenesis, are expressed in the female reproductive system, and/or are involved in tumorigenesis in general or specifically in the ovary. Our study revealed evidence that one half of the dually affected patients had an independent causation of the two conditions, thus reducing the previously estimated ovarian cancer risk for women with congenital tooth agenesis quite significantly. PMID:24631698

Bonds, John; Pollan-White, Sarah; Xiang, Lilin; Mues, Gabriele; D'Souza, Rena

2014-04-01

374

Dynamic measurements of gear tooth friction and load  

NASA Technical Reports Server (NTRS)

As part of a program to study fundamental mechanisms of gear noise, static and dynamic gear tooth strain measurements were made on the NASA gear-noise rig. Tooth-fillet strains from low-contact ratio-spur gears were recorded for 28 operating conditions. A method is introduced whereby strain gage measurements taken from both the tension and compression sides of a gear tooth can be transformed into the normal and frictional loads on the tooth. This technique was applied to both the static and dynamic strain data. The static case results showed close agreement with expected results. For the dynamic case, the normal-force computation produced very good results, but the friction results, although promising, were not as accurate. Tooth sliding friction strongly affected the signal from the strain gage on the tensionside of the tooth. The compression gage was affected by friction to a much lesser degree. The potential of the method to measure friction force was demonstrated, but further refinement will be required before this technique can be used to measure friction forces dynamically with an acceptable degree of accuracy.

Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

1991-01-01

375

Young's modulus and hardness of shark tooth biomaterials.  

PubMed

To date, the majority of studies on feeding mechanics in sharks have focused on the movement of cranial components and muscle function, with little attention to tooth properties or function. Attributes related to mechanical properties, such as structural strength, may also be subjected to natural selection. Additionally it is necessary to characterize these properties in order to construct biomechanical models of tooth function. The goal of this study was to determine hardness and elastic modulus for the shark tooth materials enameloid, osteodentine, and orthodentine. Five teeth each from one carcharhiniform species, the bonnethead Sphyrna tiburo, and one lamniform, the sand tiger shark Carcharias taurus, were utilized for nanoindentation testing. Each tooth was sectioned transversely, air-dried, and polished. Both enameloid and dentine were tested on each tooth via a Berkovich diamond tip, with nine 2 microm deep indentations per material. t-Tests were used to determine if there were differences in hardness and Young's modulus between the tooth materials of the two species. There was no significant difference between the two species for the material properties of enameloid, however both hardness and Young's modulus were higher for osteodentine than for orthodentine. This may be due to differences in microanatomy and chemical composition, however this needs to be studied in greater detail. PMID:20102762

Whitenack, Lisa B; Simkins, Daniel C; Motta, Philip J; Hirai, Makoto; Kumar, Ashok

2010-03-01

376

Discharge activities of neurons in the nucleus paragigantocellularis during the development of morphine tolerance and dependence: a single unit study in chronically implanted rats  

PubMed Central

The nucleus paragigantocellularis (PGi) has been proposed to play a role in opiate dependence/withdrawal. In the present study, we examined the discharge activity of PGi neurons before and after the development of morphine tolerance/dependence in rats. A multi-wire electrode was chronically implanted in the PGi, which allowed us to monitor the effects of both acute and chronic morphine treatments on the activity of PGi neurons recorded from the same site. We found that acute morphine excited, inhibited or had no effect on 36%, 35% or 29% of PGi neurons (N=556), respectively. After 3 days of continuous morphine infusion, which led to morphine tolerance/dependence, the firing rates of both excitatory and inhibitory PGi neurons returned to pre-morphine treatment levels, indicating that the PGi neurons developed tolerance to both excitatory and inhibitory effects of morphine. Naltrexone-precipitated withdrawal from chronic morphine treatment also induced heterogeneous responses in the PGi. On a site-by-site basis, most of the sites that showed excitatory response to acute morphine exhibited inhibitory response during withdrawal, and all the sites that showed inhibitory response to acute morphine exhibited excitatory response during withdrawal. Correlation analysis further quantitatively showed that PGi neurons’ responses to acute morphine and that during withdrawal were inversely correlated with a correlation coefficient of 0.73, suggesting that adaptations in the PGi during the development of morphine dependence share common neural mechanisms with the acute effect of morphine. These results provide new insights into the role of the PGi in the development of morphine tolerance/dependence. PMID:20371225

Zhu, Hong; Zhou, Wu

2010-01-01

377

Ultrasound and Fluoroscopy-Guided Placement of Central Venous Ports via Internal Jugular Vein: Retrospective Analysis of 1254 Port Implantations at a Single Center  

PubMed Central

Objective To assess the technical success and complication rates of the radiologic placement of central venous ports via the internal jugular vein. Materials and Methods We retrospectively reviewed 1254 central venous ports implanted at our institution between August 2002 and October 2009. All procedures were guided by using ultrasound and fluoroscopy. Catheter maintenance days, technical success rates, peri-procedural, as well as early and late complication rates were evaluated based on the interventional radiologic reports and patient medical records. Results A total of 433386 catheter maintenance days (mean, 350 days; range 0-1165 days) were recorded. The technical success rate was 99.9% and a total of 61 complications occurred (5%), resulting in a post-procedural complication rate of 0.129 of 1000 catheter days. Among them, peri-procedural complications within 24 hours occurred in five patients (0.4%). There were 56 post-procedural complications including 24 (1.9%, 0.055 of 1000 catheter days) early and 32 (2.6%, 0.074 of 1000 catheter days) late complications including, infection (0.6%, 0.018 of 10000 catheter days), thrombotic malfunction (1.4%, 0.040 of 1000 catheter days), nonthrombotic malfunction (0.9%, 0.025 of 1000 catheter days), venous thrombosis (0.5%, 0.014 of 1000 catheter days), as well as wound problems (1.1%, 0.032 of 1000 catheter days). Thirty six CVPs (3%) were removed due to complications. Bloodstream infections and venous thrombosis were the two main adverse events prolonging hospitalization (mean 13 days and 5 days, respectively). Conclusion Radiologic placement of a central venous port via the internal jugular vein is safe and efficient as evidenced by its high technical success rate and a very low complication rate. PMID:22563269

Ahn, Se Jin; Chung, Jin Wook; An, Sang Bu; Yin, Yong Hu; Jae, Hwan Jun; Park, Jae Hyung

2012-01-01

378

Strontium coating by electrochemical deposition improves implant osseointegration in osteopenic models.  

PubMed

Osteopenia, a preclinical state of osteoporosis, restricts the application of adult orthodontic implant anchorage and tooth implantation. Strontium (Sr) is able to promote bone formation and inhibit bone absorption. The aim of the present study was to evaluate a new method for improving the success rate of dental implantation. In this study, an electrochemical deposition (ECD) method was used to prepare a Sr coating on a titanium implant. The coating composition was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction, and the surface morphology of the coating was studied using scanning electron microscopy. A total of 24 Sprague-Dawley rats received bilateral ovariectomy (OVX) and an additional 12 rats underwent a sham surgery. All rats were then implanted in the bilateral tibiae with titanium mini-implants with or without a Sr coating. The results of histological examination and a fluorescence double labeling assay showed strong new bone formation with a wider zone between the double labels, a higher rate of bone mineralization and better osseointegration in the OVX rats that received Sr-coated implants compared with the OVX rats that received uncoated implants. The study indicates that Sr coatings are easily applied by an ECD method, and that Sr coatings have a promoting effect on implant osseointegration in animals with osteopenia. PMID:25452797

Liang, Yongqiang; Li, Haoyan; Xu, Jiang; Li, Xin; Li, Xinchang; Yan, Yuting; Qi, Mengchun; Hu, Min

2015-01-01

379

Microstructure and properties of single crystal BaTiO3 thin films synthesized by ion implantation-induced layer transfer  

E-print Network

extensively reported. Single crystal ferroelectric thin films can be used in applications such as actuator Institute of Physics. [DOI: 10.1063/1.1773373] Ferroelectric thin films have been widely explored, and have promise for high work/volume mechanical actuators in microelectromechanical systems (MEMS

Atwater, Harry

380

Air atmospheric-pressure plasma-jet treatment enhances the attachment of human gingival fibroblasts for early peri-implant soft tissue seals on titanium dental implant abutments.  

PubMed

Abstract Objective. Although dental implants are commonly used for tooth restoration, there is a lack of studies of treatment regimens for preventing extra-oral infection and decreasing osseointegration failures by establishing early peri-implant soft tissue seals on titanium dental implant abutments. In this study, air atmospheric-pressure plasma-jet (AAPPJ) treatment was applied to titanium disks to assay the potential for early peri-implant soft tissue seals on titanium dental implant abutment. Materials and methods. After titanium disks were treated with AAPPJ for 10 s at 250, 500, 1000 and 1500 sccm, surface analysis was performed; the control group received air only or no treatment. Human gingival fibroblasts (HGF) were seeded onto the specimens for evaluating cell attachment and proliferation and adherent-cell morphology was visualized via confocal microscopy. Results. In AAPPJ-treated specimens, the water contact angle decreased according to increased flow rate. Oxygen composition increased in XPS, but no topographical changes were detected. The effect of AAPPJ treatment at 1000 sccm was apparent 2 mm from the treated spot, with a 20% increase in early cell attachment and proliferation. Adherent HGF on AAPPJ-treated specimens displayed a stretched phenotype with more vinculin formation than the control group. Conclusions. Within the limitations of this study, the results indicate that AAPPJ treatment may enhance the early attachment and proliferation of HGF for establishing early peri-implant soft tissue seals on titanium dental implant abutments with possible favorable effects of osseointegration of dental implant. PMID:25183251

Lee, Jung-Hwan; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2015-01-01

381

Breast reconstruction - implants  

MedlinePLUS

... be filled with either saline or a silicone gel. You may have another minor procedure later that ... breast reconstruction with implants are: The implant may break or leak in the first 10 years. If ...

382

The Ion Implanter  

NSDL National Science Digital Library

This web site displays and describes the major components of a modern high current ion implanter. It uses a series of clickable image maps to help navigate. The site describes the entire process of ion implantation.

2012-07-31

383

Tooth-surface-specific Effects of Xylitol  

PubMed Central

The Xylitol for Adult Caries Trial was a three-year, double-blind, multi-center, randomized clinical trial that evaluated the effectiveness of xylitol vs. placebo lozenges in the prevention of dental caries in caries-active adults. The purpose of this secondary analysis was to investigate whether xylitol lozenges had a differential effect on cumulative caries increments on different tooth surfaces. Participants (ages 21-80 yrs) with at least one follow-up visit (n = 620) were examined at baseline, 12, 24, and 33 months. Negative binomial and zero-inflated negative binomial regression models were used to estimate incidence rate ratios (IRR) for xylitol’s differential effect on cumulative caries increments on root and coronal surfaces and, among coronal surfaces, on smooth (buccal and lingual), occlusal, and proximal surfaces. Participants in the xylitol arm developed 40% fewer root caries lesions (0.23 D2FS/year) than those in the placebo arm (0.38 D2FS/year; IRR = 0.60; 95% CI [0.44, 0.81]; p < .001). There was no statistically significant difference between xylitol and control participants in the incidence of smooth-surface caries (p = .100), occlusal-surface caries (p = .408), or proximal-surface caries (p = .159). Among these caries-active adults, xylitol appears to have a caries-preventive effect on root surfaces (ClinicalTrials.gov NCT00393055). PMID:23589387

Ritter, A.V.; Bader, J.D.; Leo, M.C.; Preisser, J.S.; Shugars, D.A.; Vollmer, W.M.; Amaechi, B.T.; Holland, J.C.

2013-01-01

384

Intermediate Charcot-Marie-Tooth disease.  

PubMed

Charcot-Marie-Tooth (CMT) disease is a common neurogenetic disorder and its heterogeneity is a challenge for genetic diagnostics. The genetic diagnostic procedures for a CMT patient can be explored according to the electrophysiological criteria: very slow motor nerve conduction velocity (MNCV) (<15 m/s), slow MNCV (15-25 m/s), intermediate MNCV (25-45 m/s), and normal MNCV (>45 m/s). Based on the inheritance pattern, intermediate CMT can be divided into dominant (DI-CMT) and recessive types (RI-CMT). GJB1 is currently considered to be associated with X-linked DI-CMT, and MPZ, INF2, DNM2, YARS, GNB4, NEFL, and MFN2 are associated with autosomal DI-CMT. Moreover, GDAP1, KARS, and PLEKHG5 are associated with RI-CMT. Identification of these genes is not only important for patients and families but also provides new information about pathogenesis. It is hoped that this review will lead to a better understanding of intermediate CMT and provide a detailed diagnostic procedure for intermediate CMT. PMID:25326399

Liu, Lei; Zhang, Ruxu

2014-12-01

385

Implantation characteristics by boron cluster ion implantation  

NASA Astrophysics Data System (ADS)

Recently, boron cluster implantation (i.e. decaborane: B10Hx+) is regarded as a promising technology for the formation of P-type Ultra Shallow Junction (USJ) because of the equivalent high beam current with less beam divergence compared to the conventional B+ or BF2+ implantation. Also as-implanted and after-annealing characteristics are different due to the appearance of self-amorphized layer by the cluster ion bombardment, which suppresses the channeling and enhances the boron activation. However, it is anticipated that the properties caused by this amorphous layer will vary with different implantation conditions or a presence of Pre Amorphization Implantation (PAI) process, which should be understood well to maintain a good process control. From this point of view, we have measured the decaborane implantation characteristics by a couple of different related conditions, for instance, the beam energy and current. Sheet resistance vs junction depth (Rs-Xj) are also evaluated in different annealing methods with combination of PAI processes. In addition, a brief comparison is made by implanting the different boron cluster ions (i.e. B8Hx+) by mass selecting the ions extracted from decaborane ionization chamber. In this paper, these characteristics of boron cluster implantations are reviewed.

Nagayama, Tsutomu; Hamamoto, Nariaki; Umisedo, Sei; Tanjyo, Masayasu; Aoyama, Takayuki

2006-11-01

386

Histology of tooth attachment tissues and plicidentine in Varanus (Reptilia: Squamata), and a discussion of the evolution of amniote tooth attachment.  

PubMed

Few recent studies have examined the histological basis for tooth attachment in squamates. In the past few years, a surge of interest in this topic has led to the intriguing suggestion that the major tissues derived from the tooth germ (enamel, dentine, cementum and alveolar bone), are conservative and are present in all amniotes. In this study, we describe the histology and development of the tooth attachment complex in Varanus rudicollis, the rough-neck monitor. We provide the first published evidence for the role of cementum and alveolar bone in tooth attachment in varanoid lizards. In Varanus, cementum is deposited on the external surface of the tooth root as well as at the base of the tooth, where it plays a role in the attachment of the tooth to the jawbone. Alveolar bone is also involved in tooth ankylosis. Our results support the hypothesis that the major tooth germ tissues are found in all amniotes. We provide insights into the structure and development of plicidentine, defined as infolding of the dentine around the tooth base. This feature is unique to varanoids among extant tetrapods and is the third tissue implicated in tooth attachment in Varanus. Plicidentine develops asymmetrically along the labial-lingual axis of a tooth. Varanus is characterized by the presence of both primary and higher-order lamellae, which anastomose to form a honeycomb-like surface that then interacts with the more basal attachment tissues. PMID:21618268

Maxwell, Erin E; Caldwell, Michael W; Lamoureux, Denis O; Budney, Lisa A

2011-10-01

387

Autocrine and paracrine Shh signaling are necessary for tooth morphogenesis, but not tooth replacement in snakes and lizards (Squamata).  

PubMed

Here we study the role of Shh signaling in tooth morphogenesis and successional tooth initiation in snakes and lizards (Squamata). By characterizing the expression of Shh pathway receptor Ptc1 in the developing dentitions of three species (Eublepharis macularius, Python regius, and Pogona vitticeps) and by performing gain- and loss-of-function experiments, we demonstrate that Shh signaling is active in the squamate tooth bud and is required for its normal morphogenesis. Shh apparently mediates tooth morphogenesis by separate paracrine- and autocrine-mediated functions. According to this model, paracrine Shh signaling induces cell proliferation in the cervical loop, outer enamel epithelium, and dental papilla. Autocrine signaling within the stellate reticulum instead appears to regulate cell survival. By treating squamate dental explants with Hh antagonist cyclopamine, we induced tooth phenotypes that closely resemble the morphological and differentiation defects of vestigial, first-generation teeth in the bearded dragon P. vitticeps. Our finding that these vestigial teeth are deficient in epithelial Shh signaling further corroborates that Shh is needed for the normal development of teeth in snakes and lizards. Finally, in this study, we definitively refute a role for Shh signaling in successional dental lamina formation and conclude that other pathways regulate tooth replacement in squamates. PMID:19850027

Handrigan, Gregory R; Richman, Joy M

2010-01-01

388

Decaborane ion implantation  

Microsoft Academic Search

The continued scaling of integrated circuit devices has resulted in the need for lower and lower implant energy capabilities. The difficulties associated with extraction and transport of low energy beams have lead to research in novel techniques for ultra low energy implantation. Results from one such technique, decaborane ion implantation, are reported here. Decaborane is a molecule with 10 boron

A. S. Perel; W. Krull; D. Hoglund; K. Jackson; T. Horsky

2000-01-01

389

Ablation plasma ion implantation  

Microsoft Academic Search

The novel hybrid technique, Ablation Plasma Ion Implantation (APII), has been characterized and optimized for ion implantation and\\/or thin film deposition. In APII, a solid target is ablated by a laser; the resulting plasma plume is the source of ions, which are accelerated to high energy by a negative bias voltage imposed on the substrate. The ions are implanted into

Bo Qi

2002-01-01

390

Shading of ceramic crowns using digital tooth shade matching devices.  

PubMed

In the 1990s, there was great optimism due to the development of devices for measuring tooth shade. The frequently not so simple, visual determination of the shade of a tooth was to be done with the aid of a device which recognizes the shade and describes it accurately by reference to a color chart. However, the skepticism towards such devices was also great. It is known that the color effect frequently differs strongly when comparing a tooth from the shade guide with a metal ceramic crown, despite identical shade designation. Anyone who considers visual shade determination to be inadequate and places his hopes in digital shade matching devices will be disappointed. It is the shade-generating structures of the metal ceramic and frequently of the veneer layers that turn out to be too thin which, despite correct shade selection, cause a different color perception. Such problems have been reduced decisively with the development of fracture-proof hard porcelain caps (Vita In-Ceram) with optical characteristics similar to teeth. In addition, the Vita System 3D-Master tooth shade system developed in 1998 by Vita in cooperation with Dr. Hall from Australia, leads the practitioner to a better understanding of the primary tooth shade characteristics of "brightness (value)", "color intensity (chroma)" and "color (wave length of the visible light, hue)". These two innovations allow a more accurate estimate of the basic shade of a natural tooth (reference tooth) and the imitation in the laboratory of its natural, shade-generating structures. If digital shade measurement supplements the visual shade estimate, then a further improvement can be expected--especially in the recognition of the basic shade. Qualitative descriptions of subjective shade measurement of a natural tooth and of its imitation in the dental laboratory by ceramics can be found frequently in professional journals and publications. With digital tooth shade matching devices, which apart from the color code of the color chart also reproduce exact, colorimetric values, such work processes can be recorded quantitatively and objectively. Reports about this type of controlled shade determination and generation are found rarely in the literature, which is surprising in view of the large number of tooth shade matching devices and dental ceramic systems available. In the present paper, the influence of the individual ceramic layers on color perception is measured and described under standardized conditions. The creation of the basic shade as it results from the composition of the various ceramic layers is traced with a spectrophotometer. The Vita In-Ceram Alumina infiltration ceramic and the VitaVM7 veneer ceramic were selected as the ceramic system. MHT-SpectroShade and Vita Easyshade were used as shade matching devices. PMID:16201397

Baltzer, A; Kaufmann-Jinoian, V

2005-04-01

391

Effects of Ion-Releasing Tooth-Coating Material on Demineralization of Bovine Tooth Enamel  

PubMed Central

We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

Kawasaki, Koji; Kambara, Masaki

2014-01-01

392

Effects of ion-releasing tooth-coating material on demineralization of bovine tooth enamel.  

PubMed

We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

Kawasaki, Koji; Kambara, Masaki

2014-01-01

393

Experimental investigation of fatigue behavior of spur gear in altered tooth-sum gearing  

NASA Astrophysics Data System (ADS)

This paper deals with the contact stress, power loss, and pitting of spur gear tooth in altered tooth-sum gearing for a tooth-sum of 100 teeth when altered by ±4% tooth-sum. Analytical and experimental methods were performed to investigate and compare the altered tooth-sum gearing against the standard tooth-sum gearing. The experiments were performed using a power recirculating type test rig. The tooth loads for the experimental investigations were determined considering the surface durability of gears. A clear picture of the surface damage was obtained using a scanning electron microphotograph. The negative alteration in the tooth-sum performed better than the positive alteration in a tooth-sum operating between specified center distances.

Sachidananda, H. K.; Gonsalvis, Joseph; Prakash, H. R.

2012-09-01

394

Modified Titanium Implant as a Gateway to the Human Body: The Implant Mediated Drug Delivery System  

PubMed Central

The aim of this study was to investigate the efficacy of a proposed new implant mediated drug delivery system (IMDDS) in rabbits. The drug delivery system is applied through a modified titanium implant that is configured to be implanted into bone. The implant is hollow and has multiple microholes that can continuously deliver therapeutic agents into the systematic body. To examine the efficacy and feasibility of the IMDDS, we investigated the pharmacokinetic behavior of dexamethasone in plasma after a single dose was delivered via the modified implant placed in the rabbit tibia. After measuring the plasma concentration, the areas under the curve showed that the IMDDS provided a sustained release for a relatively long period. The result suggests that the IMDDS can deliver a sustained release of certain drug components with a high bioavailability. Accordingly, the IMDDS may provide the basis for a novel approach to treating patients with chronic diseases. PMID:25136624

Park, Young-Seok; Cho, Joo-Youn; Hwang, Chee Il

2014-01-01

395

Audiovisual segregation in cochlear implant users.  

PubMed

It has traditionally been assumed that cochlear implant users de facto perform atypically in audiovisual tasks. However, a recent study that combined an auditory task with visual distractors suggests that only those cochlear implant users that are not proficient at recognizing speech sounds might show abnormal audiovisual interactions. The present study aims at reinforcing this notion by investigating the audiovisual segregation abilities of cochlear implant users in a visual task with auditory distractors. Speechreading was assessed in two groups of cochlear implant users (proficient and non-proficient at sound recognition), as well as in normal controls. A visual speech recognition task (i.e. speechreading) was administered either in silence or in combination with three types of auditory distractors: i) noise ii) reverse speech sound and iii) non-altered speech sound. Cochlear implant users proficient at speech recognition performed like normal controls in all conditions, whereas non-proficient users showed significantly different audiovisual segregation patterns in both speech conditions. These results confirm that normal-like audiovisual segregation is possible in highly skilled cochlear implant users and, consequently, that proficient and non-proficient CI users cannot be lumped into a single group. This important feature must be taken into account in further studies of audiovisual interactions in cochlear implant users. PMID:22427963

Landry, Simon; Bacon, Benoit A; Leybaert, Jacqueline; Gagné, Jean-Pierre; Champoux, François

2012-01-01

396

Criteria to manage the technical and biologic success of an implant abutment.  

PubMed

To maximize esthetics in anterior implant restorations, the initial step in treatment planning should be determining the prosthesis's esthetic integration with the patient's smile in keeping with the patient's anatomical limitations. This article examines the role of the abutment in supporting both esthetics and technical success. Included are discussions regarding cemented versus screw-retained restorations, material selection for anterior tooth replacement, and design parameters. PMID:25198874

Hermanides, Leon

2014-01-01

397

An alternative multiple pontic design for a fixed implant-supported prosthesis.  

PubMed

In situations of moderate residual ridge resorption where multiple tooth replacement is needed, and where the patient desires a fixed implant-supported restoration, it is challenging to design a pontic-tissue interface. The semiconvex multiple pontic design described in this article, with its mucosal contact exerted with moderate pressure, is proposed to circumvent the problems encountered with the plaque accumulation, maintenance conditions, phonetics, and compromised esthetics frequently encountered in these patients. The use of a screw-retained, implant-supported restoration is also emphasized to allow for sufficient tissue contact during placement of the prosthesis and for prosthesis retrievability for maintenance or technical reasons. PMID:21889007

Del Castillo, Rafael; Ercoli, Carlo; Delgado, Juan Carlos; Alcaraz, Jaime

2011-09-01

398

Whole genome sequencing reveals novel non-synonymous mutation in ectodysplasin A (EDA) associated with non-syndromic X-linked dominant congenital tooth agenesis.  

PubMed

Congenital tooth agenesis in human is characterized by failure of tooth development during tooth organogenesis. 300 genes in mouse and 30 genes in human so far have been known to regulate tooth development. However, candidature of only 5 genes viz. PAX9, MSX1, AXIN2, WNT10A and EDA have been experimentally established for congenitally missing teeth like hypodontia and oligodontia. In this study an Indian family with multiple congenital tooth agenesis was identified. Pattern of inheritance was apparently autosomal dominant type with a rare possibility to be X-linked. Whole genome sequencing of two affected individuals was carried out which revealed 119 novel non-synonymous single nucleotide variations (SNVs) distributed among 117 genes. Out of these only one variation (c.956G>T) located at exon 9 of X-linked EDA gene was considered as pathogenic and validated among all the affected and unaffected family members and unrelated controls. This variation leads to p.Ser319Ile change in the TNF homology domain of EDA (transcript variant 1) protein. In silico analysis predicts that this Ser319 is well conserved across different vertebrate species and a part of putative receptor binding site. Structure based homology modeling predicts that this amino acid residue along with four other amino acid residues nearby, those when mutated known to cause selective tooth agenesis, form a cluster that may have functional significance. Taken together these results suggest that c.956G>T (p.Ser319Ile) mutation plausibly reduces the receptor binding activity of EDA leading to distinct tooth agenesis in this family. PMID:25203534

Sarkar, Tanmoy; Bansal, Rajesh; Das, Parimal

2014-01-01

399

Whole Genome Sequencing Reveals Novel Non-Synonymous Mutation in Ectodysplasin A (EDA) Associated with Non-Syndromic X-Linked Dominant Congenital Tooth Agenesis  

PubMed Central

Congenital tooth agenesis in human is characterized by failure of tooth development during tooth organogenesis. 300 genes in mouse and 30 genes in human so far have been known to regulate tooth development. However, candidature of only 5 genes viz. PAX9, MSX1, AXIN2, WNT10A and EDA have been experimentally established for congenitally missing teeth like hypodontia and oligodontia. In this study an Indian family with multiple congenital tooth agenesis was identified. Pattern of inheritance was apparently autosomal dominant type with a rare possibility to be X-linked. Whole genome sequencing of two affected individuals was carried out which revealed 119 novel non-synonymous single nucleotide variations (SNVs) distributed among 117 genes. Out of these only one variation (c.956G>T) located at exon 9 of X-linked EDA gene was considered as pathogenic and validated among all the affected and unaffected family members and unrelated controls. This variation leads to p.Ser319Ile change in the TNF homology domain of EDA (transcript variant 1) protein. In silico analysis predicts that this Ser319 is well conserved across different vertebrate species and a part of putative receptor binding site. Structure based homology modeling predicts that this amino acid residue along with four other amino acid residues nearby, those when mutated known to cause selective tooth agenesis, form a cluster that may have functional significance. Taken together these results suggest that c.956G>T (p.Ser319Ile) mutation plausibly reduces the receptor binding activity of EDA leading to distinct tooth agenesis in this family. PMID:25203534

Sarkar, Tanmoy; Bansal, Rajesh; Das, Parimal

2014-01-01

400

Hard and soft tissue augmentation to enhance implant predictability and esthetics: ‘The perio-esthetic approach’  

PubMed Central

Dental implants are being increasingly applied in the restoration of partial and completely edentulous patients. Often, in these patients, soft and hard tissue defects result from a variety of causes, such as, periodontal infection, trauma, and tooth loss. These create an anatomically less favourable foundation for ideal implant placement. For prosthetic-driven dental implant therapy, reconstruction of the alveolar bone, through a variety of regenerative surgical procedures has become predictable. This article documents the soft and hard tissue treatment management of a patient with Generalized Chronic Periodontitis, who required hard and soft tissue augmentation of the ridge, prior to implant placement. We augmented the height and width of the ridge (Seibert's Class III ridge deficiency) using an Autogenous J-shaped graft involving the chin and lower border of the mandible, followed by soft tissue augmentation of the ridge with a subepithelial connective tissue graft. A significant increase in the ridge dimensions was achieved. PMID:21772724

Gita, V. Bagavad; Chandrasekaran, S. C.

2011-01-01

401

Implant Supported Mandibular Overdenture: A Viable Treatment Option for Edentulous Mandible  

PubMed Central

The prosthetic management of the edentulous patient has long been a major challenge. Complete maxillary and mandibular dentures have been the traditional standard of care. However, most of the patients report problems adapting to their mandibular denture due to a lack of comfort, retention, stability and inability to masticate. Implant-supported overdentures have been a common treatment for edentulous patients for the past 20 years and predictably achieve good clinical results. Implant supported overdentures offer many practical advantages over conventional complete dentures and removable partial dentures. These include decreased bone resorption, reduced prosthesis movement, better esthetics, improved tooth position, better occlusion, increased occlusal function and maintenance of the occlusal vertical dimension. This article presents a design and fabrication technique of the implant-retained overdenture that uses four freestanding mandibular implants. PMID:24995252

Lambade, Pravin; Gundawar, Sham

2014-01-01

402

Monte Carlo simulation for light propagation in 3D tooth model  

NASA Astrophysics Data System (ADS)

Monte Carlo (MC) simulation was implemented in a three dimensional tooth model to simulate the light propagation in the tooth for antibiotic photodynamic therapy and other laser therapy. The goal of this research is to estimate the light energy deposition in the target region of tooth with given light source information, tooth optical properties and tooth structure. Two use cases were presented to demonstrate the practical application of this model. One case was comparing the isotropic point source and narrow beam dosage distribution and the other case was comparing different incident points for the same light source. This model will help the doctor for PDT design in the tooth.

Fu, Yongji; Jacques, Steven L.

2011-03-01

403

Finite element analysis of stress distribution at the tooth-denture base interface of acrylic resin teeth debonding from the denture base.  

PubMed

Acrylic resin teeth present a problem when they detach unexpectedly from the denture base resin. Detachment is caused by stress concentrations at the tooth/denture base resin interface. In this study, the finite element method was used to examine the stress distribution at this interface when a single static force that resembled incisal bite force was applied. The results indicated that irrespective of the type of acrylic resin teeth used, maximum tensile stresses were found at the palatal aspect of the interface. It is suggested that boxing the tooth in the acrylic resin will help redistribute stress concentrations favorably. PMID:8778382

Darbar, U R; Huggett, R; Harrison, A; Williams, K

1995-12-01

404

Brief communication: Tigaran (Point Hope, Alaska) tooth drilling.  

PubMed

In a sample of 48 adult Tigarans (1300-1700 A.D.) from Point Hope, Alaska, 33 exhibited various degrees of periodontal disease, which, in 25, resulted in tooth loss (Schwartz, unpublished data). Although extreme examples of tooth wear were prevalent in the sample, carious infection was noted in only one individual, in whom the lower central incisors (I1S) had been affected. In the left I1, infection had spread through the root's apex into the alveolar bone, causing an abscess. The buccal (labial) side of the root of this tooth, just below the crown, bears a shallow, relatively flat-bottomed depression, with a small perforation into, as well as a second hole that fully penetrates, the root canal. Both of these features appear to have been produced by an implement, and, as they are associated with a diseased tooth, and ritualistic tooth shaping or drilling of any sort was, and is, not practiced among Arctic groups, their purpose was probably therapeutic. As such, this specimen appears to represent a case of precontact New World Arctic dentistry. PMID:7645674

Schwartz, J H; Brauer, J; Gordon-Larsen, P

1995-05-01

405

Tooth wear among patients suffering from mental disorders  

PubMed Central

Summary Aim Assess oral health, treatment needs and the correlation between tooth wear and medications in patients with psychiatric disease. Methodology 92 patients (40 male and 52 female) admitted in the Department of Neurology and Psychiatry of the Umberto I Hospital of Rome underwent an oral and dental clinical examination in accordance according to World Health Organization Basic Methods Criteria. One dentist performed all clinical examinations, training and calibration was carried out by an experienced clinical examiner. To measure the degree of inter-examiner agreement Kappa statistics was calculated. Level of tooth wear was assessed using the tooth wear classification of Johansson et al. Exact psychiatric pathology and medications of each patient were registrated. The Statistical Package for the Social Sciences (SPSS Inc., Chicago, Ill.) was used to analyze the data. A value of P < 0.05 was considered statistically significant. Results 34.78% of the sample regarding tooth wear demonstrated score 2. Men demonstrated 30% score 2, and 20% score 3 and 4 whereas female patients 38.46% score 2, 7.69% score 3 and none score 4. Conclusions Chronic exposure to neuroleptic drugs can cause phenomena of bruxism. There is a direct correlation between tooth wear, psychiatric disorders and administration of certain drugs. Poor oral hygiene and extensive unmet needs for dental treatment were widespread among psychiatric patients. PMID:25002918

Piccoli, Luca; Besharat, Laith Konstantinos; Cassetta, Michele; Migliau, Guido; Di Carlo, Stefano; Pompa, Giorgio

2014-01-01

406

Amorphous clusters in Co implanted ZnO induced by boron pre-implantation  

SciTech Connect

We demonstrate the formation of superparamagnetic/ferromagnetic regions within ZnO(0001) single crystals sequently implanted with B and Co. While the pre-implantation with B plays a minor role for the electrical transport properties, its presence leads to the formation of amorphous phases. Moreover, B acts strongly reducing on the implanted Co. Thus, the origin of the ferromagnetic ordering in local clusters with large Co concentration is itinerant d-electrons as in the case of metallic Co. The metallic amorphous phases are non-detectable by common X-ray diffraction.

Potzger, K.; Shalimov, A.; Zhou, S.; Schmidt, H.; Mucklich, A.; Helm, M.; Fassbender, J.; Liberati, M.; Arenholz, E.

2009-02-09

407

Hallux rigidus: cheilotomy or implant?  

PubMed

Fifty-one feet in 42 patients with varying degrees of symptomatic hallux rigidus and with 2 years of follow-up have been operated with excellent results. Cheilotomy was performed in all cases with only cheilotomy employed in the young patients and implant surgery (single-stem silicone) reserved for the older and more advanced arthritis cases. Pain generally disappeared within 3 months. Range of toe motion in dorsiflexion increased. All patients returned to their activity of choice. All patients were able to utilize off-the-shelf footwear postoperatively. There have been no fractures or inflammatory reactions of the implants as yet, including those inserted 4 or more years ago. PMID:7349857

Gould, N

1981-05-01

408

Benzocyclobutene (BCB) based neural implants with microfluidic channel  

Microsoft Academic Search

Benzocyclobutene (BCB) based intracortical neural implants for basic neuroscience research in animal models was fabricated, in which microfluidic channel was embedded to deliver chemical reagents. BCB presents several attractive features for chronic applications: flexibility, biocompatibility, desirable chemical and electrical properties, and can be easily manufactured using existing batch microfabrication technology; The fabricated implants have single shank with three recording sites

K. Lee; J. He; L. Wang

2004-01-01

409

Comparative Clinical Study of Two Tooth Bleaching Protocols with 6% Hydrogen Peroxide  

PubMed Central

Objective. The objective was to compare the clinical efficacy of two different tooth bleaching protocols after 1 and 2 weeks of treatment with an over-the-counter paint-on gel containing 6% hydrogen peroxide. Material and methods. Sixteen volunteer patients (minimum shade A2 or darker on maxillary teeth) were selected to participate in this randomized, single-blind (examiner-blinded), single-center, 2-group clinical trial using a divided mouth model. The product was applied in our clinic to one hemi-arch (Group I) in each patient at two sessions one week apart, making five applications at each session (separated by 10 min intervals). The patients themselves applied the product once a day for 10 days in the other hemiarch (Group II). Efficacy was measured according to the Vita Classical shade guide at baseline and at one and two weeks. Differences between groups (office-treated vs. home-treated hemiarches) were tested by repeated-measures analysis of variance. Results. Significant (P < .05) differences in shade values were detected between pre- and post-bleaching in both groups. The two groups did not significantly differ in tooth shade at the end of the treatment. Conclusions. Treatment with 6% hydrogen peroxide gel using the paint-on system shows significant clinical efficacy whether applied by clinicians or by the patients themselves. PMID:20339457

Oteo Calatayud, Jesús; Mateos de la Varga, Paloma; Oteo Calatayud, Carlos; Calvo Box, María José

2009-01-01

410

Influence of Implant Position on Stress Distribution in Implant-Assisted Distal Extension Removable Partial Dentures: A 3D Finite Element Analysis  

PubMed Central

Objective: Distal extension removable partial denture is a prosthesis with lack of distal dental support with a 13-fold difference in resiliency between the mucosa and the periodontal ligament, resulting in leverage during compression forces. It may be potentially destructive to the abutments and the surrounding tissues. The aim of this study was to assess the effect of implant location on stress distribution, in distal extension implant assisted removable partial dentures. Materials and Methods: Three-dimensional models of a bilateral distal extension partially edentulous mandible containing anterior teeth and first premolar in both sides of the arch, a partial removable denture and an implant (4×10mm) were designed. With the aid of the finite element program ANSYS 8.0, the models were meshed and strictly vertical forces of 10 N were applied to each cusp tip. Displacement and von Mises Maps were plotted for visualization of results. Results: When an implant was placed in the second premolar region, the highest stress on implant, abutment tooth and cancellous bone was shown. The lowest stress was shown on implant and bone in the 1st molar area. Conclusion: Implants located in the first molar area showed the least distribution of stresses in the analyzed models. PMID:25628678

Memari, Yeganeh; Geramy, Allahyar; Fayaz, Amir; Rezvani Habib Abadi, Shirin; Mansouri, Yasaman

2014-01-01

411

Telescopic Overdenture Supported by a Combination of Tooth and an Implant: A Clinical Report  

Microsoft Academic Search

The conventional modality of treatment of partial edentulousness with reduced number of teeth was to render them complete\\u000a edentulous and provide them complete denture or an overdenture with support of few remaining teeth. The goal of maintenance\\u000a of roots are to prevent alveolar bone resorption, provide better load transmission, maintain sensory feedback and achieve\\u000a better stability of denture with emphasis

Ponsekar A. Abraham; Pradeep Koka; K. Murugesan; M. Vasanthakumar

2010-01-01

412

Nanotechnology and Dental Implants  

PubMed Central

The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of implants to bone rather than fibrous tissue encapsulation. Surfaces properties such as chemistry and roughness play a determinant role in these biological interactions. Physicochemical features in the nanometer range may ultimately control the adsorption of proteins as well as the adhesion and differentiation of cells. Nanotechnologies are increasingly used for surface modifications of dental implants. Another approach to enhance osseointegration is the application of thin calcium phosphate (CaP) coatings. Bioactive CaP nanocrystals deposited on titanium implants are resorbable and stimulate bone apposition and healing. Future nanometer-controlled surfaces may ultimately direct the nature of peri-implant tissues and improve their clinical success rate. PMID:21253543

Lavenus, Sandrine; Louarn, Guy; Layrolle, Pierre

2010-01-01

413

Bizarre tooth surface loss and the Miswak stick.  

PubMed

Tooth surface loss can present in a variety of ways, some of which can appear rather strange on first examination. This case report demonstrates an unusual presentation of tooth surface loss (TSL) and its subsequent treatment. This loss of hard dental tissue appeared to be affecting the whole of the patient's remaining dentition, both lingually and buccally. Detailed questioning revealed the origins of this problem which turned out to be due to excessive use of an intra-oral Miswak chewing stick. Cinical Relevance: This article will enable clinicians to understand the importance of specific, targeted history-taking, involving a rare case of tooth surface loss as well as the use of minimally destructive restoration composites and a fibre-reinforced composite bridge. PMID:24930258

Karia, Roshni; Kelleher, Martin G

2014-05-01

414

Multidisciplinary Treatment Options of Tooth Avulsion Considering Different Therapy Concepts  

PubMed Central

Background: Avulsion of permanent front teeth is a rare accident, mostly affecting children between seven and nine years of age. Replanted and splinted, these teeth often develop inflammation, severe resorption or ankylosis affecting alveolar bone development and have to be extracted sooner or later. Objectives: The purpose of this study was to evaluate different therapy concepts to create a structured concept for the treatment of avulsions. Results: Based on existing therapy concepts, a concept for different initial conditions (dry time, age, growth, tooth, hard and soft tissues) was developed and is presented here. Conclusion: A great deal of research has been performed during recent years and guidelines for the management of avulsions have been published. With the help of this literature it is possible to identify the best treatment procedure for each tooth. Clinical Relevance: The prognosis of avulsed teeth can be improved by considering evidence-based therapy concepts. Resorption, ankylosis and tooth loss could be minimized. PMID:25352922

Kostka, Eckehard; Meissner, Simon; Finke, Christian H; Mandirola, Manlio; Preissner, Saskia

2014-01-01

415

Genetic Approaches for the Diagnosis and Treatment of Congenital Tooth Agenesis  

E-print Network

disorder, such new therapeutic strategies for the prevention of tooth agenesis should be attempted. In this research project I have pursued two objectives: 1.) Basic research into the molecular genetics and therapeutics of the tooth agenesis gene PAX9...

Bonds, John Carless

2014-08-06

416

New Visions of Dental Tissue Research: Tooth Development, Chemistry, and Structure  

E-print Network

of tooth formation, stress expe- rienced during development, and the age at death of juveniles. Incremen estimates of tooth formation, until recently these types of studies have been limited to small samples due

Smith, Tanya M.

417

Tooth Contact Shift in Loaded Spiral Bevel Gears  

NASA Technical Reports Server (NTRS)

An analytical method is presented to predict the shifts of the contact ellipses of spiral bevel gear teeth under load. The contact ellipse shift is the motion of the tooth contact position from the ideal pitch point to its location under load. The shifts are due to the elastic motions of the gear and pinion supporting shafts and bearings. The calculations include the elastic deflections of the gear shafts and the deflections of the four shaft bearings. The method assumes that the surface curvature of each tooth is constant near the unloaded pitch point. Results from these calculations will help designers reduce transmission weight without seriously reducing transmission performance.

Savage, M.; Altidis, P. C.; Lewicki, D. G.; Coy, J. J.; Litvin, F. L.

1989-01-01

418

Effect of umbilical cord mesenchymal stem cell in peri-implant bone defect after immediate implant: an experiment study in beagle dogs  

PubMed Central

Background: For the sake of reducing post extraction resorption, getting optimal positioning of the implant and shortening treatment time, immediate implant placement following tooth extraction has been proposed as a treatment option. However, the large bone defect peri-implant has a negative influence on the process of bone healing. In this study, umbilical cord mesenchymal stem cells (UCMSCs) were transplanted into the bone defect peri-implant in beagle dogs and the effect of UCMSCs on bone regeneration in peri-implant were assessed. Methods: The mandibular second, third and fourth premolars of 8 beagle dogs were extracted bilaterally. The defects in one side were filled with platelet-rich fibrin (PRF) and then UCMSCs were injected into the defect area, while the defects in the other side were filled with PRF only as control group. The titanium implant was placed into the distal root socket of each extracted tooth. The animals were sacrificed at week 2, 4 and 8 post operation. The bone defects adjacent to the implant which are 4 mm in height, 4 mm in the mesio-distal direction and 3.5 mm in the bucco-lingual direction were made after immediate implant. Histomorphometric analysis was performed using methylene blue-fuchsin acid staining and hematoxylin and eosin (HE) staining to evaluate bone regeneration. Results: The direct bone-to-implant contact (BIC) in the experiment after 4 and 8 weeks was 56.47 ± 1.18% and 76.23 ± 2.08%; and in the control group was40.79 ± 0.65% and 61.17 ± 2.79%, respectively. The percentage of newly formed bone after 2, 4 and 8 weeks was 17.60 ± 1.5%, 49.82 ± 4.02% and 67.16 ± 2.1% in experiment group; and in control group 14.30 ± 1.25%, 37.04 ± 2.29% and 58.83 ± 3.36%, respectively. These results represented significant differences statistically. Conclusion: Intra-bone marrow injection of UCMSCs can promote new bone formation. UCMSCs can be used to as excellent seed cells to repair the large defect peri-implant after immediate implant. PMID:25550923

Hao, Peng-Jie; Wang, Zhi-Guo; Xu, Quan-Chen; Xu, Sheng; Li, Zhuo-Ri; Yang, Pi-Shan; Liu, Zhong-Hao

2014-01-01

419

Effect of umbilical cord mesenchymal stem cell in peri-implant bone defect after immediate implant: an experiment study in beagle dogs  

PubMed Central

Background: For the sake of reducing post extraction resorption, getting optimal positioning of the implant and shortening treatment time, immediate implant placement following tooth extraction has been proposed as a treatment option. However, the large bone defect peri-implant has a negative influence on the process of bone healing. In this study, umbilical cord mesenchymal stem cells (UCMSCs) were transplanted into the bone defect peri-implant inbeagle dogs and the effect of UCMSCs on bone regeneration in peri-implant were assessed. Methods: The mandibular second, third and fourth premolars of 8 beagle dogs were extracted bilaterally. The defects in one side were filled with platelet-rich fibrin (PRF) and then UCMSCs were injected into the defect area, while the defects in the other side were filled with PRF only as control group. The titanium implant was placed into the distal root socket of each extracted tooth. The animals were sacrificed at week 2, 4 and 8 post operative. The bone defects adjacent to the implant which are 4 mm in height, 4 mm in the mesio-distal direction and 3.5 mm in the bucco-lingual direction were made after immediate implant. Histomorphometric analysis was performed using methylene blue-fuchsin acid staining and hematoxylin and eosin (HE) staining to evaluate bone regeneration. Results: The direct bone-to-implant contact (BIC) in the experiment after 4 and 8 weeks was 56.47±1.18% and 76.23±2.08%; and in the control group was40.79±0.65% and 61.17±2.79%, respectively. The percentage of newly formed bone after 2, 4 and 8 weeks was 17.60±1.5%, 49.82±4.02% and 67.16±2.1% in experiment group; and in control group 14.30±1.25%, 37.04±2.29% and 58.83±3.36%, respectively. These results represented significant differences statistically. Conclusion: Intra-bone marrow injection of UCMSCs can promote new bone formation. UCMSCs can be used to as excellent seed cells to repair the large defect peri-implant after immediate implant. PMID:25550885

Hao, Peng-Jie; Wang, Zhi-Guo; Xu, Quan-Chen; Xu, Sheng; Li, Zhuo-Ri; Yang, Pi-Shan; Liu, Zhong-Hao

2014-01-01

420

High-energy x-ray optics with silicon saw-tooth refractive lenses.  

SciTech Connect

Silicon saw-tooth refractive lenses have been in successful use for vertical focusing and collimation of high-energy X-rays (50-100 keV) at the 1-ID undulator beamline of the Advanced Photon Source. In addition to presenting an effectively parabolic thickness profile, as required for aberration-free refractive optics, these devices allow high transmission and continuous tunability in photon energy and focal length. Furthermore, the use of a single-crystal material (i.e. Si) minimizes small-angle scattering background. The focusing performance of such saw-tooth lenses, used in conjunction with the 1-ID beamline's bent double-Laue monochromator, is presented for both short ({approx}1:0.02) and long ({approx}1:0.6) focal-length geometries, giving line-foci in the 2 {micro}m-25 {micro}m width range with 81 keV X-rays. In addition, a compound focusing scheme was tested whereby the radiation intercepted by a distant short-focal-length lens is increased by having it receive a collimated beam from a nearer (upstream) lens. The collimation capabilities of Si saw-tooth lenses are also exploited to deliver enhanced throughput of a subsequently placed small-angular-acceptance high-energy-resolution post-monochromator in the 50-80 keV range. The successful use of such lenses in all these configurations establishes an important detail, that the pre-monochromator, despite being comprised of vertically reflecting bent Laue geometry crystals, can be brilliance-preserving to a very high degree.

Shastri, S. D.; Almer, J. A.; Ribbing, C. R.; Cederstrom, B. C.; X-Ray Science Division; Uppsala Univ.; Royal Inst. of Tech.

2007-01-01

421

Scales and Tooth Whorls of Ancient Fishes Challenge Distinction between External and Oral ‘Teeth’  

PubMed Central

The debate about the origin of the vertebrate dentition has been given fresh fuel by new fossil discoveries and developmental studies of extant animals. Odontodes (teeth or tooth-like structures) can be found in two distinct regions, the ‘internal’ oropharyngeal cavity and the ‘external’ skin. A recent hypothesis argues that regularly patterned odontodes is a specific oropharyngeal feature, whereas odontodes in the external skeleton lack this organization. However, this argument relies on the skeletal system of modern chondrichthyans (sharks and their relatives), which differ from other gnathostome (jawed vertebrate) groups in not having dermal bones associated with the odontodes. Their external skeleton is also composed of monoodontode 'placoid scales', whereas the scales of most early fossil gnathostomes are polyodontode, i.e. constructed from several odontodes on a shared bony base. Propagation phase contrast X-ray Synchrotron microtomography (PPC-SRµCT) is used to study the polyodontode scales of the early bony fish Andreolepis hedei. The odontodes constructing a single scale are reconstructed in 3D, and a linear and regular growth mechanism similar to that in a gnathostome dentition is confirmed, together with a second, gap-filling growth mechanism. Acanthodian tooth whorls are described, which show that ossification of the whorl base preceded and probably patterned the development of the dental lamina, in contrast to the condition in sharks where the dental lamina develops early and patterns the dentition.The new findings reveal, for the first time, how polyodontode scales grow in 3D in an extinct bony fish. They show that dentition-like odontode patterning occurs on scales and that the primary patterning unit of a tooth whorl may be the bony base rather than the odontodes it carries. These results contradict the hypothesis that oropharyngeal and external odontode skeletons are fundamentally separate and suggest that the importance of dermal bone interactions to odontode patterning has been underestimated. PMID:23951264

Qu, Qingming; Sanchez, Sophie; Blom, Henning; Tafforeau, Paul; Ahlberg, Per Erik

2013-01-01

422

Occlusal concepts application in resolving implant prosthetic failure: case report.  

PubMed

The prosthetic management of a poor implant treatment is presented in this case report. The recommended occlusion concepts for implant-supported prostheses were applied for the resolution of the case. The rehabilitation of the posterior segments provided a mutually protected occlusion with adequate distribution of the axial and lateral bite forces with stable posterior occlusion. The clinical exam indicated the need for modification in the vertical dimension of occlusion. Sufficient interocclusal rest space was present to test the alteration in the vertical dimension. The aim was to achieve an occlusion scheme that followed four specific criteria: (1) centric contacts and centric relation of the jaw-to-jaw position; (2) anterior guidance only; (3) shallow anterior angle of tooth contact; and (4) vertical dimension of occlusion with acceptable tooth form and guidance. The success of an oral rehabilitation relies in following the aforementioned criteria, appropriate interaction between the dental laboratory technician and the clinician, careful elaboration of the provisional rehabilitation with all the desired details to be reproduced in the final prosthetic restoration and sufficient follow-up time of the provisional prostheses before placing the final restoration. PMID:22251257

Jamcoski, Vanessa Helena; Faot, Fernanda; de Mattias Sartori, Ivete Aparecida; Vieira, Rogéria Acedo; Tiossi, Rodrigo

2014-04-01

423

Biomechanical evaluation of subcrestal dental implants with different bone anchorages.  

PubMed

This study evaluated the biomechanical influence of apical bone anchorage on a single subcrestal dental implant using three-dimensional finite element analysis (FEA). Four different bone anchorage designs were simulated on a posterior maxillary segment using one implant with platform switching and internal Morse taper connection as follows: 2 mm subcrestal placement with (SW) or without (SO) the implant apex engaged into the cortical bone or position at bone level with anchorage only in the crestal cortical (BO) bone or with bicortical fixation (BW). Each implant received a premolar crown, and all models were loaded with 200 N to simulate centric and eccentric occlusion. The peak tensile and compressive stress and strain were calculated at the crestal cortical, trabecular, and apical cortical bone. The vertical and horizontal implant displacements were measured at the platform level. FEA indicated that subcrestal placement (SW and SO) created lower stress and strain in the crestal cortical bone compared with crestal placement (BO and BW models). The SW model exhibited lesser vertical and horizontal implant micromovement compared with the SO and BO models under eccentric loading; however, stress and strain were higher in the apical cortical bone. The BW model exhibited the lowest implant displacement. These results indicate that subcrestal placement decreases the stress in the crestal cortical bone of dental implants, regardless of apical anchorage; however, apical cortical anchorage can be effective in limiting implant displacement. Further studies are required to evaluate the effects of possible remodeling around the apex on the success of subcrestal implants. PMID:25098822

Sotto-Maior, Bruno Salles; Lima, Camila de Andrade; Senna, Plínio Mendes; Camargos, Germana de Villa; Del Bel Cury, Altair Antoninha

2014-01-01