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1

Single-tooth implant-supported restorations. Planning for an aesthetic and functional solution.  

PubMed

The single-tooth implant has found widespread support within the field of implant dentistry, with numerous studies reporting high success rates that surpass those recorded for splinted implant bridgework. Improvements in implant design, range of prosthetic components and restorative materials have made it possible to achieve optimal functional and cosmetic results. Coupled with an appropriate approach to treatment planning and patient assessment, use of the single-tooth implant may be considered a highly predictable treatment solution. PMID:11476031

Norton, M R

2001-05-01

2

Key factors for predictable aesthetics in single tooth immediate implantation with provisionalization.  

PubMed

Early implant placement is one treatment option for implant therapy following a single-tooth extraction in the anterior maxilla. In this article some key factors are presented to analyze and follow in an effort to obtain a predictable and acceptable esthetic result. The creation of predictable peri-implant esthetics requires proper preservation of the osseous and soft tissues around the failing teeth, proper 3-D implant placement and proper understanding of the prosthetic management. The surgical technique presented here is characterized by tooth extraction without flap elevation, implant placement in a correct three-dimensional position, simultaneous contour augmentation on the facial aspect with connective tissue grafting combined with heterologous bone chips filled into the implant bone gap. PMID:24390020

Redemagni, Marco; Garlini, Giuliano; D'Amato, Salvatore

2013-12-01

3

In vitro comparison of master cast accuracy for single-tooth implant replacement  

Microsoft Academic Search

Statement of Problem: The inaccuracy in transferring the position of the hexagonal head of a single implant to the working cast can result in a final single tooth crown, which clinically may present occlusal and\\/or interproximal contacts that are different from those contacts on the master cast obtained by the technician. Purpose: This in vitro study evaluated the accuracy of

Paolo Vigolo; Zeina Majzoub; Giampiero Cordioli

2000-01-01

4

Immediate single tooth replacement with subepithelial connective tissue graft using platform switching implants: a case series.  

PubMed

This case series evaluated the facial gingival stability following single immediate tooth replacement in conjunction with subepithelial connective tissue graft (SCTG). Implant success rate and peri-implant tissue response were also reported. Ten patients (6 male, 4 female), with a mean age of 52.1 (range = 22.7 to 67.1) years, underwent immediate implant placement and provisionalization with SCTG and were evaluated clinically and radiographically at presurgery (T0), at the time of immediate tooth replacement and SCTG (T1), and 3 months (T2), 6 months (T3), and 12 months (T4) after surgery. Data were analyzed using the Friedman and Wilcoxon signed-ranks tests at the significance level of ? = .05. At 1 year, 9 of 10 implants remained osseointegrated with the overall mean marginal bone change of -0.31 mm and a mean facial gingival level change of -0.05 mm. The modified plaque index scores showed that patients were able to maintain a good level of hygiene throughout the study. The papilla index score indicated that at T4, more than 50% of the papilla fill was observed in 89% of all sites. When proper 3-dimensional implant position is achieved and bone graft is placed into the implant-socket gap, favorable success rate and peri-implant tissue response of platform switching implants can be achieved following immediate tooth replacement in conjunction with subepithelial connective tissue graft. PMID:20883114

Chung, Seunghwan; Rungcharassaeng, Kitichai; Kan, Joseph Y K; Roe, Phillip; Lozada, Jaime L

2011-10-01

5

ImplantsA 3 to 4 year study of single tooth hydroxylapatite coated endosseous dental implants  

Microsoft Academic Search

Objective To evaluate the clinical effectiveness, common complications and maintenance associated with hydroxylapatite (HA) coated cylindrical implants when used to support single crowns.Design A prospective medium term clinical study of the Calcitek HA-coated implant.Setting Implant placement, crown fabrication and follow-up procedures were carried out at the Leeds Dental Institute, between 1990 and 1998.Subjects and method 26 patients (33 implants) participated

C J Watson; D Tinsley; A R Ogden; J L Russell; S Mulay; E M Davison

1999-01-01

6

Immediate loading of single-tooth implants in the anterior maxilla. Preliminary results after one year.  

PubMed

According to the standard protocol, a load-free healing period is one of the most emphasized requirements for implant integration. Recent studies have encouraged a progressive shortening of the healing period for single-tooth implants and immediate loading has been proposed for the aesthetic zone in the maxilla. The present study evaluated clinical outcomes of immediately loaded FRIALIT-2 Synchro implants 12 months after placement in the maxillary incisal region. In the course of our investigation, nine patients have been treated following an immediate loading protocol. The stepped-screw type implants were inserted with an increasing torque up to 45 Ncm, thus measuring the primary stability of the implants. All implants were immediately restored with unsplinted acrylic resin provisional crowns and the patients provided with occlusal splints. Regular controls were performed at monthly intervals, intraoral radiographs were taken directly after implant placement, 6 and 12 months post insertion. The survival rate, clinical stability (Periotest) and radiographic coronal bone defects (CBD) were evaluated at delivery of the definitive superstructures (CBD 6) and 6 months later (CBD 12). Twelve FRIALIT-2 Synchro stepped screws of 3.8, 4.5 and 5.5 mm diameter and 13 and 15 mm length were placed in the incisal maxillary region. The median Periotest value 6 months post insertion was -2 with a minimum of -5 and a maximum of +2. The mean coronal bone level changes (CBD) at 6 and 12 months were 0.45 and 0.75 mm. No implant failed up to 12 months after insertion, resulting in a 100% survival rate. The presented results showed promising data for immediately loaded single-tooth implants in the anterior maxilla. Periotest values were within the range published for submerged implants. The radiographic coronal bone resorption after 6 and 12 months was even less than evaluated for implants placed in a standard two-stage procedure. It is evident that successful immediate loading protocols require a careful and strict patient selection aimed at achieving the best primary stability and avoiding any excessive functional or non-functional loading. Additional research needs to be done to provide data in situations where problems of poor bone quality, multiple implants or augmentation procedures must be overcome. PMID:12656877

Lorenzoni, Martin; Pertl, Christof; Zhang, Kehao; Wimmer, Gernot; Wegscheider, Walther A

2003-04-01

7

Early implant placement following single-tooth extraction in the esthetic zone: biologic rationale and surgical procedures.  

PubMed

Early implant placement is one treatment option for implant therapy following single-tooth extraction in the anterior maxilla. The surgical technique presented here is characterized by tooth extraction without flap elevation, a 4- to 8-week soft tissue healing period, implant placement in a correct three-dimensional position, simultaneous contour augmentation on the facial aspect with guided bone regeneration using a bioabsorbable collagen membrane combined with autogenous bone chips and a low-substitution bone filler, and tension-free primary wound closure. The surgical step-by-step procedure is presented with a case report. In addition, the biologic rationale is discussed. PMID:18990995

Buser, Daniel; Chen, Stephen T; Weber, Hans Peter; Belser, Urs C

2008-10-01

8

Master Cast Accuracy in Single-Tooth Implant Replacement Cases: An In Vitro Comparison. A Technical Note  

Microsoft Academic Search

Purpose: This in vitro study evaluated the accuracy of master casts obtained by using (1) copings mod- ified by sandblasting and coating their roughened surfaces with impression adhesive before final impression procedures and (2) gold machined UCLA abutments as impression copings in final impres- sion procedures for single-tooth implant replacement cases. Materials and Methods: A polymeric resin model with a

Paolo Vigolo; Fulvio Fonzi; Zeina Majzoub; Giampiero Cordioli

9

CLINICAL EVALUATION OF HYDROXYAPATITE COATED SINGLE-TOOTH IMPLANTS: A 5YEAR RETROSPECTIVE STUDY  

Microsoft Academic Search

The use of implants to replace missing single teeth has become a valuable treatment option. This study presents a 5-year retrospective clinical analysis of single teeth replaced with hydroxyapatite-coated implants. Of the 271 cylinder and screw implants placed over this period, 12 were lost (survival rate = 95.57%). In addition to aes- thetic compromise, the most frequent complication was loosening

Helda Maria Barcellos Ferreira; William Meirelles Frossard; Nassin David Harari

10

Placement of single tooth implant in healed socket with immediate temporization: Clinical study  

PubMed Central

Introduction: Edentulous condition inadequately compensated for, by dentures, impair oral function and is accompanied by reduced self–confidence. In a continued effort to achieve these goals, implant dentistry was introduced. Immediate temporization is somehow a recent concept, which allows the maintenance of soft tissue contours, along with interdental alveolar contours. Aims and Obectives: Aims of the present study were to study the placement of implant in the post-extracted healed tooth socket of anterior maxilla and to evaluate the feasibility of early function on implants placed. Materials and Methods: In the present study, HI-TECH IMPLANTS TRX-OP one-piece immediate loading implant system with the built on abutment has been used. Immediate temporisation has been done and results have been evaluated in terms of stability, gingival health, esthetics, marginal bone loss, patient's psychological attitude, and satisfaction. Results: Out of eight implants, 6 successfully healed whereas 2 implants suffered failure. Conclusion: Overall conclusion drawn from the study is, immediate temporization is a successful method providing psychological, financial and emotional benefits to the patient. PMID:23633800

Lata, Jeevan; Parmar, Monika

2012-01-01

11

Long term clinical evaluation of Ha-coated titanium dental implant for single tooth  

Microsoft Academic Search

A single-stage long-term clinical trial was given for indigenously prepared hydroxyapatite coated titanium screw-type dental implant in six young adults using suitably designed and produced implant kit. Under local anaesthesia, bone was drilled at a very low speed (30 rpm) and implants were screwed in place. Clinical mobility was tested and radiographs were taken at a periodical interval up to

T. K. Pal; S. Pal

1995-01-01

12

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

13

Single-Tooth Morse Taper Connection Implant Placed in Grafted Site of the Anterior Maxilla: Clinical and Radiographic Evaluation  

PubMed Central

The aim of this study was to achieve aesthetically pleasing soft tissue contours in a severely compromised tooth in the anterior region of the maxilla. For a right-maxillary central incisor with localized advanced chronic periodontitis a tooth extraction followed by reconstructive procedures and delayed implant placement was proposed and accepted by the patient. Guided bone regeneration (GBR) technique was employed, with a biphasic calcium-phosphate (BCP) block graft placed in the extraction socket in conjunction with granules of the same material and a resorbable barrier membrane. After 6 months of healing, an implant was installed. The acrylic provisional restoration remained in situ for 3 months and then was substituted with the definitive crown. This ridge reconstruction technique enabled preserving both hard and soft tissues and counteracting vertical and horizontal bone resorption after tooth extraction and allowed for an ideal three-dimensional implant placement. Localized severe alveolar bone resorption of the anterior maxilla associated with chronic periodontal disease can be successfully treated by means of ridge reconstruction with GBR and delayed implant insertion; the placement of an early-loaded, Morse taper connection implant in the grafted site was effective to create an excellent clinical aesthetic result and to maintain it along time. PMID:25431687

Mangano, Francesco Guido; Zecca, Piero; Luongo, Fabrizia; Iezzi, Giovanna; Mangano, Carlo

2014-01-01

14

Single-Tooth Implants  

MedlinePLUS

... oral surgeon or general dentist with training in implantology performs this procedure. It is done using a plastic surgical guide made by your prosthodontist or general dentist. The guide fits over your existing teeth and extends over the area where teeth are ...

15

Soft tissue contour changes at immediate postextraction single-tooth implants with immediate restoration: a 12-month prospective cohort study.  

PubMed

In the maxillary arch from premolar to premolar, 26 single dental implants were inserted in fresh extraction sockets and immediately provisionalized. The bone-to-implant gap was grafted with a bovine bone mineral. After 3 months, definitive ceramic crowns were placed. At baseline and after 1 year, the soft tissue horizontal width, mesiodistal papillary level, midfacial gingival level, and pink esthetic score were evaluated. No statistical differences were found between baseline and 1 year for all parameters. Immediate singletooth implants, with immediate restoration, are capable of maintaining the soft tissue contour and esthetics compared to the pretreatment status. PMID:25738339

Cardaropoli, Daniele; Tamagnone, Lorenzo; Roffredo, Alessandro; Gaveglio, Lorena

2015-01-01

16

FEM evaluation of cemented-retained versus screw-retained dental implant single-tooth crown prosthesis  

PubMed Central

Prosthetic rehabilitation of partial or total edentulous patients is today a challenge for clinicians and dental practitioners. The application of dental implants in order to recover areas of missing teeth is going to be a predictable technique, however some important points about the implant angulation, the stress distribution over the bone tissue and prosthetic components should be well investigated for having final long term clinical results. Two different system of the prosthesis fixation are commonly used. The screw retained crown and the cemented retained one. All of the two restoration techniques give to the clinicians several advantages and some disadvantages. Aim of this work is to evaluate all the mechanical features of each system, through engineering systems of investigations like FEM and Von Mises analyses. The FEM is today a useful tool for the prediction of stress effect upon material and biomaterial under load or strengths. Specifically three different area has been evaluated through this study: the dental crown with the bone interface; the passant screw connection area; the occlusal surface of the two different type of crown. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed an adequate response for both type of prostheses, although cemented retained one showed better results over the occlusal area. PMID:24955150

Cicciu, Marco; Bramanti, Ennio; Matacena, Giada; Guglielmino, Eugenio; Risitano, Giacomo

2014-01-01

17

Hydroxyapatite-coated tooth implants by laser  

Microsoft Academic Search

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

Miroslav Jelinek; Tatjana Dostalova; Lucia Himmlova; Christos Grivas

1996-01-01

18

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

19

Finite Element Analysis of Biomechanical Interactions of A Tooth-Implant Splinting System for Various Bone Qualities  

Microsoft Academic Search

Background: The splinting of an implant and tooth is a rational alternative in some clinical situations. The complex biomechanical aspects of a tooth-implant system are derived from the dissimilar mobility between the osseointegrated implant and the tooth. The aim of this study was to analyze the biomechanics in a tooth-implant splinting system for various bone qualities with different occlusal forces

Chun-Li Lin; Shih-Hao Chang; Jen-Chyan Wang

20

Cemented and screw-retained implant-supported single-tooth restorations in the molar mandibular region: A retrospective comparison study after an observation period of 1 to 4 years  

PubMed Central

Objectives: The aim of this study was to evaluate the survival and compare the appearance of different mechanical and biological complications, in screw-retained and cemented-retained single-tooth implant-supported restorations localized in the molar mandibular region, over a period of 1 to 4 years. Material and Methods: A retrospective study was carried out with a total of eighty implant-supported restorations, which were placed in eighty patients for prosthetic rehabilitation of a mandibular molar. Forty patients were rehabilitated with a cemented-retained restoration and the other forty with a screw-retained restoration. The presence of the following complications was recorded for both types of prostheses: Fractures of the ceramic veneering, loosening screws, mucositis and peri-implantitis. Debonding of the restoration was analyzed in the cemented-retained restoration group. The clinical survival of crowns was analyzed with a Kaplan-Meier test and the clinical complications were compared, using a Student t test and Log-rank test. Results: 27 patients registered some complication. The average rate of complications was 37,5% for cemented-retained restorations and 30% for screw-retained restorations. The complications more common in the cemented-retained restoration were the presence of mucositis (14,87%), while in the screw-retained restorations was the loosening screw (20%). Student t test and Log-Rank test found significant differences (p=0,001) between the screw loosening and presence of mucositis. Conclusions: The cemented-retained restorations seem to prevent screw loosening, but the presence of cement seem to increase the complications around the soft tissues, however in the screw-retained restorations the presence of mucositis and peri-implantitis are lower than cemented-retained restorations. The incidence of fracture of ceramic veneering was similar in both groups. Key words:Screw-retained restorations, cemented-retained restorations, screw loosening, peri-implant diseases and fracture ceramic veneering.

Peñarrocha-Diago, Miguel; Pradíes, Guillermo; Sola-Ruiz, María-Fernanda; Agustín-Panadero, Rubén

2015-01-01

21

Fracture behaviour of implant–implant- and implant–tooth-supported all-ceramic fixed dental prostheses utilising zirconium dioxide implant abutments  

Microsoft Academic Search

This in vitro study investigated the fracture behaviour of implant–implant-supported and implant–tooth-supported all-ceramic\\u000a fixed dental prostheses (FDP) using zirconium dioxide implant abutments (FRIADENT® CERCON® abutments, DENTSPLY Friadent).\\u000a Six different test groups (n?=?8) were prepared. Groups 1, 2, 4, and 5 represented an implant–implant-supported FDP condition, whereas groups 3 and 6\\u000a simulated an implant–tooth-supported FDP condition. The second right premolar of

Frank Philipp Nothdurft; Sabine Merker; Peter Reinhard Pospiech

2011-01-01

22

Total rehabilitation of maxilla using a tooth-to-implant restoration: case report.  

PubMed

Dental implants in partially edentulous patients are a predictable therapeutic option. However, using tooth-to-implant restorations to rehabilitate partially edentulous patients involves highly complex biomechanical aspects. This type of prosthesis utilizes different kinds of support that react distinctly to the functional forces developed in the oral cavity. In some cases, a tooth-to-implant restoration is a treatment option for difficulties related to reduced bone volume, inadequate interdental space, or an implant's failure to osseointegrate. This case report describes the rehabilitation of a patient whose partially edentulous maxilla was treated with a tooth-to-implant restoration. In this case, telescopic crowns were used to better match the tooth-implant union. No biomechanical or functional problems were found 8 years post-treatment, indicating that the combination of implant and tooth support is a possible treatment option with an improved long-term prognosis. PMID:24784519

de Vasconcellos, Andrea Araujo; Feitosa, Sergio Eduardo Henriques; Girundi, Francisco Mauro da Silva

2014-01-01

23

Single-Tooth Modeling for 3D Dental Model  

PubMed Central

An integrated single-tooth modeling scheme is proposed for the 3D dental model acquired by optical digitizers. The cores of the modeling scheme are fusion regions extraction, single tooth shape restoration, and single tooth separation. According to the “valley” shape-like characters of the fusion regions between two adjoining teeth, the regions of the 3D dental model are analyzed and classified based on the minimum curvatures of the surface. The single tooth shape is restored according to the bioinformation along the hole boundary, which is generated after the fusion region being removed. By using the extracted boundary from the blending regions between the teeth and soft tissues as reference, the teeth can be separated from the 3D dental model one by one correctly. Experimental results show that the proposed method can achieve satisfying modeling results with high-degree approximation of the real tooth and meet the requirements of clinical oral medicine. PMID:20689718

Yuan, Tianran; Liao, Wenhe; Dai, Ning; Cheng, Xiaosheng; Yu, Qing

2010-01-01

24

Fracture behaviour of implant-implant- and implant-tooth-supported all-ceramic fixed dental prostheses utilising zirconium dioxide implant abutments.  

PubMed

This in vitro study investigated the fracture behaviour of implant-implant-supported and implant-tooth-supported all-ceramic fixed dental prostheses (FDP) using zirconium dioxide implant abutments (FRIADENT® CERCON® abutments, DENTSPLY Friadent). Six different test groups (n?=?8) were prepared. Groups 1, 2, 4, and 5 represented an implant-implant-supported FDP condition, whereas groups 3 and 6 simulated an implant-tooth-supported FDP condition. The second right premolar of the mandible was replaced with a pontic tooth. In groups 2 and 5, implant abutments were individualised by circumferential preparation. XiVe® S plus screw implants (DENTSPLY Friadent) that were 4.5 mm (first molar) and 3.8 mm (first premolar) in diameter and 11 mm in length and metal tooth analogues with simulated periodontal mobility, representing the first right premolar, were mounted in a polymethyl methacrylate block. The FDPs were cemented with KetacCem (3 M Espe GmbH, Germany). Groups 4, 5, and 6 were thermomechanically loaded (thermal and mechanical cycling (TCML)?=?1.2?×?10?; 10,000?×?5°/55°) and subjected to static loading until failure. Statistical analysis of data obtained for the force at fracture was performed using non-parametric tests. All samples tested survived TCML. In the implant-implant-supported groups, circumferential abutment preparation resulted in a tendency to lower fracture forces compared to groups with unprepared abutments (group 1, 472.75?±?24.71 N; group 2, 423.75?±?48.48 N; group 4, 647.13?±?39.10 N; group 5, 555.86?±?30.34 N). The implant-tooth-supported restorations exhibited higher fracture loads (group 3, 736.25?±?82.23 N; group 6, 720.75?±?48.99 N) than the implant-implant-supported restorations which did not possess circumferentially individualised abutments. Statistically significant differences were found when comparing the non-artificially aged groups. Implant-tooth-supported FDP restorations did exhibit an increased fracture load compared to implant-implant-supported FDP restorations. PMID:20049497

Nothdurft, Frank Philipp; Merker, Sabine; Pospiech, Peter Reinhard

2011-02-01

25

Rehabilitation using single stage implants  

PubMed Central

Implant related prosthesis has become an integral part of rehabilitation of edentulous areas. Single stage implant placement has become popular because of its ease of use and fairly predictable results. In this paper, we present a series of cases of single stage implants being used to rehabilitate different clinical situations. All the implants placed have been successfully restored and followed up for up to one year. PMID:20376239

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

2009-01-01

26

Dimensional profile of oral mucosa around combined tooth-implant-supported bridgework in macaque mandible  

Microsoft Academic Search

Purpose: A stable oral mucosa is crucial for long-term survival and biofunctionality of implants. Most of this evidence is derived from clinical and animal studies based solely on implant-supported prosthesis. Much less is known about the dimensions and relationships of this soft tissue complex investing tooth-implant-supported bridgework (TISB). The aim here was to obtain experimental evidence on the dimensional characteristics

C. H. Siar; C. G. Toh; T. B. T. Ali; D. Seiz; S. T. Ong

2012-01-01

27

Dynamic UCLA for single tilted implant in an aesthetic region  

PubMed Central

Introduction The aim of this paper was to present a rehabilitation of a patient with a dynamic universal castable long abutment (UCLA) for a single tilted implant in the anterior maxillary area. Presentation of case A 57-year-old male patient attended the dentistry college clinic complaining of a vertical fracture of a residual root of the dental element 22. The tooth extraction was indicated for the implant installation. Due to the socket buccal wall thickness, the implant was installed with an inclination to the palate. It was done in a two-stage surgical protocol, and an external hexagon implant (3.75 × 11.5 mm) was placed. After a six-month healing period to correct the implant position, a dynamic UCLA was set in place, rectifying the implant emergence profile at 20°. The ceramic structure fitting was performed and, after the patient’s consent, the prosthesis was finalized and installed. Discussion After a follow-up period of twenty months, no complications were observed. Conclusion The installation of tilted implants with a dynamic UCLA may be a viable option, faster and less invasive than bone grafts. PMID:25618842

Goiato, Marcelo Coelho; Sônego, Mariana Vilela; da Silva, Emily Vivianne Freitas; de Carvalho Dekon, Stefan Fiuza; de Medeiros, Rodrigo Antonio; Carvalho, Karina Helga Turcio de; dos Santos, Daniela Micheline

2015-01-01

28

[Replacement of extracted tooth by means of implant-supported direct abutment. A case report].  

PubMed

Abutment manipulation, namely repeated screwing and unscrewing may have an affect on the final marginal bone level, consequently, soft tissue position around endosseous implants. In order to maintain the crestal bone level constant and avoid the apical recession of gingiva final abutment (Direct Abutment, Astra Tech) has been connected to submerged OsseoSpeed 4.5 dental implant (Astra Tech) in position of tooth 14, immediately after second surgical exposure. Following a healing period of three weeks, impression was taken using closed tray system and plastic impression pic-up for laboratory manufacturing of zirconium crown restoration. The functional and aesthetic result of the reconstruction was highly met patient is the satisfaction. The maintenance of marginal bone level and the excellent health of the peri-implant tissues, as registered at 6-month recall, may support the benefit of the idea of final abutment insertion immediately after one-, or two-stage surgery. PMID:21789935

Fazekas, Réka; Fazekas, Arpád

2011-06-01

29

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. PMID:25551013

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

2014-01-01

30

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

PubMed

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

2014-01-01

31

Retrievable, tooth-implant-supported, complete-arch fixed restorations in the maxilla: a 6-year retrospective study.  

PubMed

The aim of this retrospective study was to evaluate the survival rate of implants, abutment teeth, and suprastructures along with the management of the complications for complete-arch, semipermanent cemented tooth-implant-supported restorations in 44 maxillae. Permanent cemented copings protect the prepared teeth from caries. The metal-ceramic fixed dental prostheses (FDPs) were cemented onto copings and implant abutments using acryl-urethane cement. Data were assessed via patient records and a final clinical examination. Six years after cementation, no implant or restoration had failed. After the extraction of two teeth and placement of an additional implant, three restorations had to be subsequently changed (89% of restorations were unchanged after 6 years). The loss of retention without tooth intrusion occurred in two restorations. All 23 restoration removals for prosthetic aftercare were non-destructive. The results of this study indicate that complete-arch, semipermanently cemented FDP rigidly connecting the maxillary teeth and implants are a reliable treatment option. PMID:23089639

Mundt, Torsten; Heinemann, Friedhelm; Schwahn, Christian; Biffar, Reiner

2012-02-01

32

Single atom devices by ion implantation.  

PubMed

To expand the capabilities of semiconductor devices for new functions exploiting the quantum states of single donors or other impurity atoms requires a deterministic fabrication method. Ion implantation is a standard tool of the semiconductor industry and we have developed pathways to deterministic ion implantation to address this challenge. Although ion straggling limits the precision with which atoms can be positioned, for single atom devices it is possible to use post-implantation techniques to locate favourably placed atoms in devices for control and readout. However, large-scale devices will require improved precision. We examine here how the method of ion beam induced charge, already demonstrated for the deterministic ion implantation of 14 keV P donor atoms in silicon, can be used to implant a non-Poisson distribution of ions in silicon. Further, we demonstrate the method can be developed to higher precision by the incorporation of new deterministic ion implantation strategies that employ on-chip detectors with internal charge gain. In a silicon device we show a pulse height spectrum for 14 keV P ion impact that shows an internal gain of 3 that has the potential of allowing deterministic implantation of sub-14 keV P ions with reduced straggling. PMID:25783169

van Donkelaar, Jessica; Yang, C; Alves, A D C; McCallum, J C; Hougaard, C; Johnson, B C; Hudson, F E; Dzurak, A S; Morello, A; Spemann, D; Jamieson, D N

2015-04-22

33

Single atom devices by ion implantation  

NASA Astrophysics Data System (ADS)

To expand the capabilities of semiconductor devices for new functions exploiting the quantum states of single donors or other impurity atoms requires a deterministic fabrication method. Ion implantation is a standard tool of the semiconductor industry and we have developed pathways to deterministic ion implantation to address this challenge. Although ion straggling limits the precision with which atoms can be positioned, for single atom devices it is possible to use post-implantation techniques to locate favourably placed atoms in devices for control and readout. However, large-scale devices will require improved precision. We examine here how the method of ion beam induced charge, already demonstrated for the deterministic ion implantation of 14 keV P donor atoms in silicon, can be used to implant a non-Poisson distribution of ions in silicon. Further, we demonstrate the method can be developed to higher precision by the incorporation of new deterministic ion implantation strategies that employ on-chip detectors with internal charge gain. In a silicon device we show a pulse height spectrum for 14 keV P ion impact that shows an internal gain of 3 that has the potential of allowing deterministic implantation of sub-14 keV P ions with reduced straggling.

van Donkelaar, Jessica; Yang, C.; Alves, A. D. C.; McCallum, J. C.; Hougaard, C.; Johnson, B. C.; Hudson, F. E.; Dzurak, A. S.; Morello, A.; Spemann, D.; Jamieson, D. N.

2015-04-01

34

Considerations for single tooth replacement in an esthetic zone–review of conservative treatment options  

PubMed Central

Background This literature review aimed to identify and assess the conservative treatment options for replacing a single missing anterior tooth, for patients who cannot afford implants or traditional bridges. Materials and Methods The evidence was obtained using MEDLINE searches. A total of 19 studies met the inclusion criteria. None of these studies scored higher than 10 of 17, suggesting that all studies did not have strong evidence. Three of the studies examined resin-bonded bridges (RBBs), whereas the other three investigated removable partial dentures (RPDs). None of the studies had random patient selection. Three of these studies had controlled allocation of patients. The other three allowed new patients to enter the study throughout the study period. Placement of the prosthesis was only conducted in one study, whereas the rest of the studies examined patients with preexisting prostheses. Results and Conclusion In general, all 19 studies were weak due to poor study design, no acceptable controls, no direct comparison between RBBs and RPDs, lack of longitudinal studies and no differentiation between the anterior and posterior prostheses. Therefore, no definitive treatment conclusion can be made until studies of stronger design are conducted.

Singh, Raghuwar Dayal; Singh, Saumyendra V; Chand, Pooran; Ramashanker

2012-01-01

35

Quantum computer developement with single ion implantation  

SciTech Connect

Spins of single donor atoms are attractive candidates forlarge scale quantum information processing in silicon. Formation ofdevices with a few qubits is crucial for validation of basic ideas anddevelopment of a scalable architecture. We describe our development of asingle ion implantation technique for placement of single atoms intodevice structures. Collimated highly charged ion beams are aligned with ascanning probe microscope. Enhanced secondary electron emission due tohigh ion charge states (e.g., 31P13+, or 126Te33+) allows efficientdetection of single ion impacts. Studies of electrical activation of lowdose, low energy implants of 31P in silicon show a drastic effect ofdopant segregation to the SiO2/Si interface, while Si3N4/Si retards 31Psegregation. We discuss resolution limiting factors in ion placement, andprocess challenges for integration of single atom arrays with controlgates and single electron transistors.

Persaud, A.; Park, S.J.; Liddle, J.A.; Rangelow, I.W.; Bokor, J.; Keller, R.; Allen, F.I.; Schneider, D.H.; Schenkel, T.

2004-04-09

36

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

37

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

38

Frictional coefficients of ion-implanted alumina against ion-implanted beta-titanium in the low load, low velocity, single pass regime.  

PubMed

The frictional coefficients were measured for four wire alloys against the flats of polycrystalline alumina cylinders using a low load, low velocity, single pass device. Ion-implantations of titanium into polycrystalline alumina flats and nitrogen into beta-titanium wires reduced the static and kinetic coefficients from 0.50 and 0.44 before implantation to 0.20 and 0.25 after implantation, respectively. These results are similar in magnitude to frictional coefficients for unimplanted, control couples of stainless steel, cobalt-chromium, and nickel titanium wires against polycrystalline alumina flats. For orthodontic applications, we conclude that more efficient and reproducible appliances can be engineered for tooth movement if ion-implantation is used to reduce the abrasion of beta-titanium by polycrystalline alumina. PMID:1521704

Kusy, R P; Tobin, E J; Whitley, J Q; Sioshansi, P

1992-05-01

39

Clinical, esthetic, and radiographic evaluation of small-diameter (3.0-mm) implants supporting single crowns in the anterior region: a 3-year prospective study.  

PubMed

Fifty patients underwent single-tooth replacement in the maxillary and mandibular incisor area using two-piece 3.0-mm-diameter implants. Clinical and radiographic measurements of soft and hard tissue levels and esthetic parameters (pink esthetic score/white esthetic score [PES/WES]) were assessed at 3 years. No implant failed (success rate: 100%), and facial soft tissues and marginal bone levels remained stable throughout the study period. The mean total PES/WES was high (14.1 ± 1.75), and only one implant demonstrated an unfavorable esthetic outcome (PES/WES = 10). The use of 3.0-mm-diameter implants appears to be a viable treatment procedure in the medium term for single-tooth anterior restorations with limited dimensions. PMID:25411738

Pieri, Francesco; Siroli, Lucia; Forlivesi, Caterina; Corinaldesi, Giuseppe

2014-01-01

40

Quadricuspid aortic valve and single coronary artery in a greater white-toothed shrew, Crocidura russula.  

PubMed

An adult greater white-toothed shrew (Crocidura russula) had both a quadricuspid aortic valve and a single coronary artery arising from the aorta. The shrew was caught on 10 May 1994 in the environs of Málaga, southern Spain. Both congenital anomalies may be potential causes of cardiac dysfunction, but apparently produced no significant cardiac complication in the shrew. This is the first report of a quadricuspid aortic valve in a wild-living mammal. PMID:9359065

Durán, A C

1996-10-01

41

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. PMID:25593661

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

2014-01-01

42

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

43

Papillae alterations around single-implant restorations in the anterior maxillae: thick versus thin mucosa  

PubMed Central

To evaluate the papilla alterations around single-implant restorations in the anterior maxillae after crown attachment and to study the influence of soft tissue thickness on the papilla fill alteration. According to the inclusion criteria, 32 patients subjected to implant-supported single-tooth restorations in anterior maxillae were included. The patients were assigned to two groups according to the mucosal thickness: (i) group 1, 1.5 mm?mucosal thickness?3 mm; and (ii) group 2, 3 mmsingle-implant restorations could improve significantly over time after 6-month restoration according to PFI assessment. The thicker mucosa before implant placement implied a more favorable esthetic outcome in papilla alteration. PMID:22627613

Si, Mi-Si; Zhuang, Long-Fei; Huang, Xin; Gu, Ying-Xin; Chou, Chung-Hao; Lai, Hong-Chang

2012-01-01

44

Two-stage IMZ implants and ITI implants inserted in a single-stage procedure  

Microsoft Academic Search

The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V-VI) participated in this study. After randomisation, 20 patients received two IMZ implants

Kees Heydenrijk; Gerry M. Raghoebar; Henny J. A. Meijer; Reijden van der W. A; Winkelhoff van A. J

2002-01-01

45

Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices  

E-print Network

Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices A. Zebda1,2 , S. Cosnier1 the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal further developments. Following recent developments in nano- and biotechnology, state-of-the-art biofuel

Boyer, Edmond

46

Sex- and Age-based Differences in Single Tooth Loss in Adults.  

PubMed

The aim of this study was to investigate sex- and age-based differences in single tooth loss in adults. The data were obtained from the results of a periodontal disease examination carried out under a health promotion law in a city in Japan in 2005. Baseline data from a total of 3,872 participants aged 40 or 60 years comprising 1,302 men and 2,570 women were available. Only participants with 27 present teeth were eligible for inclusion in the analysis, giving a total of 218 men and 428 women. Third molars were excluded from the study. The bilateral total of each type of tooth was obtained. The mandibular first molar was missing in 26.7% of the men and 36.2% of the women among 40-year-olds and 35.3% of the men and 29.8% of the women among 60-year-olds. The mandibular second molar was missing in 14.7% of the men and 12.5% of the women among 40-year-olds, and 17.6% of the men and 18.4% of the women among 60-year-olds. Significant differences were observed between men and women in the mandibular second premolars and first molars among 40-year-olds. These results suggest that we need to pay more attention to individual teeth which are at particularly high risk for tooth loss, namely the mandibular first and second molars, and especially the mandibular first molars in middle-aged women. PMID:25765577

Yoshino, Koichi; Ishizuka, Yoichi; Watanabe, Hidehiko; Fukai, Kakuhiro; Sugihara, Naoki; Matsukubo, Takashi

2015-01-01

47

Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure  

PubMed Central

ABSTRACT Objectives The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement. Material and Methods Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured. Results The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P < 0.01). The age showed negative relation to bone dimension (r = - 0.32, P = 0.04). Anterior and posterior border of the maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects. Conclusions Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus. PMID:24421963

Shahbazian, Maryam; Xue, Dong; Hu, Yuqian; van Cleynenbreugel, Johan

2010-01-01

48

Immediate Provisionalization and Nonfunctional Loading of a Single Implant in the Maxillary Esthetic Zone: A Clinical Presentation and Parameters for Consideration  

PubMed Central

Restoration of single tooth loss with implant supported prosthesis is now considered a highly predictable treatment. However, the maxillary anterior region still presents a challenge for both the prosthodontist and the periodontist because of the inherent difficulties encountered in the provisionalization and harmonic incorporation of the definitive prosthesis into patient's dentogingival complex. This paper presents a clinical case of a single implant placed immediately after the extraction of a maxillary central incisor, followed by immediate provisionalization and nonfunctional loading. The surgical and the restorative techniques are described, and the parameters of consideration for this approach are presented. PMID:24383012

Michalakis, Konstantinos X.; Kalpidis, Christos D. R.; Kirmanidou, Yvone; Hirayama, Hiroshi; Calvani, Pasquale Lino; Pissiotis, Argiris L.

2013-01-01

49

Single glucose biofuel cells implanted in rats power electronic devices.  

PubMed

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

50

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

51

Engineering single photon emitters by ion implantation in diamond.  

PubMed

Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center. PMID:19956415

Naydenov, B; Kolesov, R; Batalov, A; Meijer, J; Pezzagna, S; Rogalla, D; Jelezko, F; Wrachtrup, J

2009-11-01

52

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

53

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

54

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

55

All-ceramic single-tooth restorations: choosing the material to match the preparation--preparing the tooth to match the material.  

PubMed

The shape of a crown preparation is the prime determinant for the choice of material for an all-ceramic restoration. One essential factor is the available space for the restoration, which requires a certain occlusal thickness. The dentist's preparation design determines the available vertical clearance, and the dental technician has the responsibility of advising the dentist with regard to either choosing the right material to match the preparation or to preparing the tooth to match the material. Assuming a minimum static fracture strength of > 2000 N, the following materials can be used for all-ceramic crowns: Laboratory surveys have shown that in most situations, the available occlusal clearance in clinical reality is only 0.8 to 0.9 mm (after cementing). This shows that the available space will often be insufficient for providing monoblock crowns and still on the tight side for veneered oxide ceramics (In Ceram, zirconia, etc.). However, crowns made of veneered oxide ceramics are much more complex to fabricate and much more expensive. By simply providing a minimal occlusal thickness of 1.5 mm, the treatment provider could therefore easily facilitate the use of the much more economical monoblock crowns without compromising either esthetics or strength. Actually, crowns with veneered oxide ceramic copings do not offer any higher fracture resistance compared to Mark II crowns as long as the minimum thickness requirements are met. The flexural strength of CAD/CAM-fabricated lithium disilicate rods is about twice that of CAD/CAM-fabricated Mark II rods. When used for crowns with a wall thickness of 1.5 mm, however, both materials exhibit the same fracture strength of between 2000 and 2500 N. This is related to the different reinforcing action of the adhesive luting agent, which is essentially required for both these materials. When choosing a material, preparation shapes, technical complexity and cost should be thoroughly compared and scrutinized and should figure prominently in the discussions between dentists and dental technician. Unfavorable preparation shapes for single crowns will necessitate compromises in terms of the choice of materials that result in high cost but do not offer anything in the way of higher fracture resistance. What constitutes an appropriate all-ceramic restoration for a single tooth? Do all-ceramic single crowns require the same material bulk as multi-unit bridges? Everything would indicate that a suitable preparation geometry allows feldspathic ceramic monoblock crowns to be milled that do not require any extensive finishing efforts such as thermal annealing or in-laboratory veneering while at the same time demanding no compromises in terms of esthetics and load-bearing capacity. PMID:19216315

Baltzer, A

2008-01-01

56

Nanofabrication of charge-based Si:P quantum computer devices using single-ion implantation  

Microsoft Academic Search

We report on progress towards a charge-based qubit using phosphorus atoms implanted in a silicon substrate. Prototype devices have been fabricated using standard lithographic techniques together with a new method of controlled single ion implantation using on-chip detector electrodes. Positional accuracy of the implanted ions was achieved using a nanoaperture mask defined using electron beam lithography. The two implanted phosphorus

Mladen Mitic; Soren E. Andresen; Victor C. Chan; Tilo M. Buehler; Andrew J. Ferguson; Eric Gauja; Fay E. Hudson; David J. Reilly; A. R. Hamilton; Andrew S. Dzurak; Robert G. Clark; Changyi Yang; Toby Hopf; Christopher I. Pakes; David N. Jamieson

2005-01-01

57

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

58

Tooth abscess  

MedlinePLUS

... tooth (the pulp). Infection may spread from the root of the tooth to the bones supporting the tooth. Infection results in a collection of pus and tissue swelling within the tooth. This causes a painful toothache . The toothache may stop if ...

59

Modification of single-crystal sapphire by ion implantation  

Microsoft Academic Search

Some studies have shown that single-crystal sapphire can exhibit a dramatic loss of compressive strength (over 90%) at high temperatures, limiting its use as a shatter-resistant optical window. Other studies have shown that the mechanical behavior of sapphire can be improved by ion implantation, hardening the near-surface region and introducing a compressive stress state, perhaps leading to an increase in

J. D. Demaree; J. K. Hirvonen; S. R. Kirkpatrick; A. R. Kirkpatrick

1997-01-01

60

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

61

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

62

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

63

Allotransplantation of tooth: a case report.  

PubMed

Tooth transplantation has attracted great interests since ancient times. A successful case of tooth allotransplantation is presented. A mandibular first premolar from the donor was implanted into the socket of maxillary central incisor Follow up after 12 months indicated good periapical healing with no resorption. Clinically, the transplantation site was free of symptoms and there was no evidence of periodontal disease or tooth mobility. This article suggests tooth transplantation as an alternative to other restorative options. PMID:23342558

Revathy, V; Suryakanth, M; Poornima, P; Subba Reddy, V V

2012-01-01

64

Metal-reinforced single implant mandibular overdenture retained by an attachment: a clinical report.  

PubMed

Results of studies have shown that a single implant mandibular overdenture significantly increases the satisfaction and quality of life of patients with edentulism. The single implant-retained overdenture has the additional advantage of being less expensive and invasive than a 2-implant supported overdenture but has a high incidence of fracture of the acrylic resin base at the point of the implant. The treatment, design, and fabrication of a metal-reinforced single-implant mandibular overdenture with the Locator attachment as a retention device is described. PMID:24199604

Grageda, Edgar; Rieck, Bastian

2014-01-01

65

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 ...

66

Immediate, single stage, truly anatomic zirconia implant in lower molar replacement: a case report with 2.5 years follow-up.  

PubMed

This report demonstrates the clinical use of a modified, truly anatomic, root-analogue zirconia implant for immediate replacement of a two-rooted, left first mandibular molar. A 50-year-old female patient with chronic apical periodontitis of the left mandibulary first molar was referred and the tooth was extracted. The mesial root had to be removed surgically due to a root fracture. A truly anatomical, root identical, roughened zirconia implant modified by macro-retentions was manufactured and placed into the extraction socket by tapping 7 days later. After 4 months a composite crown was cemented in place. No complications occurred during the healing period. A good functional and aesthetic result was achieved with minimal bone resorption and soft tissue recession at 30 months follow-up. This report describes the successful clinical use of an immediate, single stage, truly anatomical root-analogue zirconia implant for replacement of a two-rooted tooth. Significant modifications such as macro-retentions yielded primary stability and excellent osseointegration. This novel approach is minimally invasive, respects the underlying anatomy, aids socket prevention, is time- and cost-saving with good patient acceptance as there is no need for bone drilling, sinus lift, bone augmentation or other traumatic procedures. PMID:20833511

Pirker, W; Wiedemann, D; Lidauer, A; Kocher, A A

2011-02-01

67

Who Is an Implant Candidate?  

MedlinePLUS

Who Is an Implant Candidate? If you're interested in replacing a missing tooth or teeth, dental implants may be an option for you. Most people are good candidates for implants. A good candidate should have the following: Healthy ...

68

Single ion implantation for single donor devices using Geiger mode detectors  

NASA Astrophysics Data System (ADS)

Electronic devices that are designed to use the properties of single atoms such as donors or defects have become a reality with recent demonstrations of donor spectroscopy, single photon emission sources, and magnetic imaging using defect centers in diamond. Ion implantation, an industry standard for atom placement in materials, requires augmentation for single ion capability including a method for detecting a single ion arrival. Integrating single ion detection techniques with the single donor device construction region allows single ion arrival to be assured. Improving detector sensitivity is linked to improving control over the straggle of the ion as well as providing more flexibility in lay-out integration with the active region of the single donor device construction zone by allowing ion sensing at potentially greater distances. Using a remotely located passively gated single ion Geiger mode avalanche diode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of >75 µm from the center of the collecting junction. This detection efficiency is achieved with sensitivity to ~600 or fewer electron-hole pairs produced by the implanted ion. Ion detectors with this sensitivity and integrated with a thin dielectric, for example a 5 nm gate oxide, using low energy Sb implantation would have an end of range straggle of <2.5 nm. Significant reduction in false count probability is, furthermore, achieved by modifying the ion beam set-up to allow for cryogenic operation of the SIGMA detector. Using a detection window of 230 ns at 1 Hz, the probability of a false count was measured as ~10-1 and 10-4 for operation temperatures of ~300 K and ~77 K, respectively. Low temperature operation and reduced false, 'dark', counts are critical to achieving high confidence in single ion arrival. For the device performance in this work, the confidence is calculated as a probability of >98% for counting one and only one ion for a false count probability of 10-4 at an average ion number per gated window of 0.015.

Bielejec, E.; Seamons, J. A.; Carroll, M. S.

2010-02-01

69

Optical properties and surface roughness of ion implanted single crystal sapphire  

SciTech Connect

It has been shown that metal ion implantation can harden single crystal sapphire and introduce compressive stresses at the surface, which may lead to an increase in the fracture toughness of the material. This may significantly affect the usefulness of this material as a shatter-resistant optical window in missile applications. In this study, the authors have examined the extent to which sapphire can be implanted without severely degrading its optical quality by ion beam defect production. Optically-polished single-crystal c-axis sapphire was implanted with 150 keV Cr{sup +}, Ti{sup +}, and Si{sup +} ions to doses of 0.3--3.0 {times} 10{sup 17} ions/cm{sup 2} at both room temperature and at 800 C, to measure the optical effect of in situ annealing. Rutherford backscattering spectrometry showed evidence of implant species migration only in the case of Ti implanted at high temperatures; all other implant profiles were Gaussian. The optical transmittance of the sapphire was examined using visible spectrum transmission and Fourier Transform Infrared Spectroscopy. Si implantation resulted in a 10% reduction in infrared transmittance at the highest ion dose, but this was reduced to 6% when the implantation was done at high temperature. Both Cr and Ti implantation reduced the sapphire IR transmittance (by 16% and 42%, respectively), but the effect of implantation temperature on transmittance was different. High temperature during implantation increased the transmittance of Cr-implanted samples, but further darkened Ti-implanted samples. Photon tunneling and atomic force microscopy showed that both Ti and Cr implantation roughened the surface of the material.

Demaree, J.D.; Hirvonen, J.K. [Army Research Lab., Aberdeen Proving Ground, MD (United States). Weapons and Materials Research Directorate; Kirkpatrick, S.R.; Kirkpatrick, A.R. [Epion Corp., Bedford, MA (United States)

1997-12-01

70

Tooth Whitening  

MedlinePLUS

... or rougher enamel also affects the reflection of light and therefore the color. Every day, a thin coating (pellicle) forms on the enamel and picks up stains. Tooth enamel also contains pores that ...

71

Tooth Extraction  

MedlinePLUS

... the immune system. Wisdom teeth , also called third molars, are often extracted either before or after they ... sinus during removal of an upper back tooth (molar) — A small hole usually will close up by ...

72

Tooth Decay  

MedlinePLUS

... cavity. Your dentist calls it tooth decay or dental caries. They're all names for a hole ... or abscess. To help prevent cavities Brush your teeth every day with a fluoride toothpaste Clean between ...

73

Tooth Problems  

MedlinePLUS

... to determine if you need to see your dentist right away. SYMPTOMS DIAGNOSIS SELF-CARE Begin Here ... You have TOOTH LOSS. DENTAL EMERGENCY See your dentist or go to the emergency room right away. ...

74

Impacted tooth  

MedlinePLUS

Bad breath Difficulty opening the mouth (occasionally) Pain or tenderness of the gums (gingiva) or jaw bone Prolonged ... No treatment may be needed if the impacted tooth is not causing any problems. Over-the-counter pain relievers ...

75

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

76

Tooth Abrasion and Tooth Erosion  

MedlinePLUS

... problem is called acid reflux. People with the eating disorder bulimia can get tooth erosion because of repeated vomiting. Even the chlorine and other chemicals in a swimming pool can cause erosion over time. Symptoms Toothbrush abrasion causes V- ...

77

In situ optimization of co-implantation and substrate temperature conditions for Nv-center formation in single crystal diamonds  

SciTech Connect

We present first results from in situ characterization of NV-formation in single crystal diamonds following implantation of low energy nitrogen ions (7.7 keV), co-implantation of hydrogen, helium and carbon ions and in situ annealing. Diamond samples were implanted at room temperature or at a temperature of 780{degree} C during the implantation steps. We find that dynamic annealing during co-implantation enhances NV-center formation by up to 25%.

Schwartz, Julian; Michaelides, Philip; Weis, Christoph D.; Schenkel, Thomas

2011-02-01

78

Determination of Na acceptor level in Na+ ion-implanted ZnO single crystal  

NASA Astrophysics Data System (ADS)

Ion implantation was used to dope Na acceptor into ZnO single crystals. With three mixed implantation energies, uniform depth distribution of Na ion in the surface region (~300 nm) of ZnO bulk crystals is achieved. Via post-implantation annealing, a donor-acceptor pair recombination band is identified in the low-temperature photoluminescence spectra, from which the energy level of Na-related acceptor in single crystalline ZnO is estimated to be 300 meV. A p-n junction based on this ZnO-Na layer shows rectifying characteristics, confirming the p-type conductivity.

Wang, Zheng; Liu, Huibin; He, Haiping; Huang, Jingyun; Chen, Lingxiang; Ye, Zhizhen

2015-03-01

79

Nanomechanical characterization of cavity growth and rupture in hydrogen-implanted single-crystal BaTiO3  

E-print Network

Nanomechanical characterization of cavity growth and rupture in hydrogen-implanted single formation is related to the measured mechanical properties to better understand hydrogen implantation. Based on thermodynamic modeling, we suggest that cavities grow toward the cracking criteria

Atwater, Harry

80

Longitudinal co-site optical microscopy study on the chelating ability of etidronate and EDTA using a comparative single-tooth model.  

PubMed

In the present study the smear layer dissolution kinetics of 18% etidronate (HEBP), 9% HEBP, and 17% ethylenediaminetetraacetic acid (EDTA) on human dentin were quantitatively and longitudinally analyzed by using a single-tooth comparative model. Coronal dentin disks were prepared from 3 maxillary human molars. A standardized smear layer was produced on the pulpal side of each disk. The smear layer-covered surface was divided into 3 similar areas. Each of these was then exposed to 1 of the 3 irrigants under investigation, whereas the others were covered with adhesive tape. Co-site image sequences of the areas under investigation were obtained after several cumulative demineralization times. Sixteen images were obtained from each dentin area of each tooth for each experimental time at 1000x magnification. An image processing and analysis sequence measured sets of images, providing data of area fraction for thousands of tubules over time and allowing us to quantitatively follow the effect of the chelating substances. The Kruskal-Wallis H test and Dunn multiple comparison test were used to analyze the data. Overall, it can be concluded that the demineralization kinetics promoted by both 9% HEBP and 18% HEBP were significantly slower than those of 17% EDTA (P < .05). In addition, the single-tooth model is advantageous over the first co-site optical microscopy dentin assessments when different chelator solutions are compared. PMID:18155497

De-Deus, Gustavo; Zehnder, Matthias; Reis, Claudia; Fidel, Sandra; Fidel, Rivail Antonio Sergio; Galan, João; Paciornik, Sidney

2008-01-01

81

Mesenchymal Stem Cells and Tooth Engineering  

PubMed Central

Tooth loss compromises human oral health. Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss problems, they are thought to have safety and usage time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells (MSCs) are multipotent stem cells which can differentiate into a variety of cell types. The potential MSCs for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth (SHEDs), adult dental pulp stem cells (DPSCs), stem cells from the apical part of the papilla (SCAPs), stem cells from the dental follicle (DFSCs), periodontal ligament stem cells (PDLSCs) and bone marrow derived mesenchymal stem cells (BMSCs). This review outlines the recent progress in the mesenchymal stem cells used in tooth regeneration. PMID:20690498

Peng, Li; Ye, Ling; Zhou, Xue-dong

2009-01-01

82

Single Word and Sentence Intelligibility in Children with Cochlear Implants  

ERIC Educational Resources Information Center

This study examined the intelligibility of speech produced by 17 children (aged 4-11 years) with cochlear implants. Stimulus items included sentences from the Beginners' Intelligibility Test (BIT) and words from the Children Speech Intelligibility Measure (CSIM). Naive listeners responded by writing sentences heard or with two types of responses…

Khwaileh, Fadwa A.; Flipsen, Peter, Jr.

2010-01-01

83

An in situ annealing study of lead implanted single crystal calcium titanate  

NASA Astrophysics Data System (ADS)

In situ annealing studies have been carried out in ion-implanted single crystals of CaTiO3. These crystals were implanted along both the a and b axes of this orthorhombic perovskite structure (Pcmn). A VCR connected to a television system on a transmission electron microscope was used to observe the regrowth process and monitor the growth rate. Samples were annealed in a single tilt hot stage at approx. 475 C. The near-surface region of this material, approximately 190 nm, is turned amorphous by the implantation of 540 KeV Pb ions at a fluence of 1(10 to the 15th power/sq cm). Annealing at 475 C results in the epitaxial regrowth of the damaged region. The regrowth process begins at the original amorphous crystalline interface and proceeds outward to the surface. This phenomenon has been studied for implantations along both the <010> and the <100> crystallographic directions. For constant accelerating voltage and fluence of the implanted lead ions, transmission electron microscopy and Rutherford backscattering spectroscopy indicate that the regrowth rate is linear with time but strongly dependent on the oxygen partial pressure in the annealing atmosphere, and the implantation and subsequent regrowth direction. strongly dependent on the oxygen partial pressure in the annealing atmosphere, and the implantation and subsequent regrowth direction.

Rankin, J.; Hobbs, L. W.; Boatner, L. A.; White, C. W.

1987-07-01

84

Implants  

MedlinePLUS

... palate, which can reduce your sense of taste. Self-esteem — Because implants are so much like your natural teeth, you will think about them less. Your self-esteem and confidence will be improved because you will ...

85

An in situ annealing study of lead implanted single crystal calcium titanate  

NASA Astrophysics Data System (ADS)

In situ annealing studies have been carried out in ion-implanted single crystals of CaTiO 3. These crystals were implanted along both the a and b axes of this orthorhombic perovskite structure (Pcmn). Through the use of a Panasonic video cassette recorder connected to a Gatan television system on a JEOL 200CX transmission electron microscope, the regrowth process was observed and the growth rate monitored. Samples were annealed in a Gatan single tilt hot stage at ˜ 475° C. The near-surface region of this material, approximately 190 nm, is turned amorphous by the implantation of 540 keV Pb ions at a fluence of 1 × 10 15/cm 2. Annealing at 475° C results in the epitaxial regrowth of the damaged region. The regrowth process begins at the original amorphous/crystalline interface and proceeds outward to the surface. This phenomenon has been studied for implantations along both the <010> and the <100> crystallographic directions. For constant accelerating voltage and fluence of the implanted lead ions, transmission electron microscopy (TEM) and Rutherford backscattering spectroscopy (RBS) [C.W. White et al., to be published in Proc. of Radiation Effects in Insulators, Lyon, France, 1987.] indicate that the regrowth rate is linear with time but strongly dependent on the oxygen partial pressure in the annealing atmosphere, and the implantation and subsequent regrowth direction.

Rankin, J.; Hobbs, L. W.; Boatner, L. A.; White, C. W.

1988-05-01

86

Mechanism for diamond nucleation and growth on single crystal copper surfaces implanted with carbon  

NASA Technical Reports Server (NTRS)

The nucleation and growth of diamond crystals on single-crystal copper surfaces implanted with carbon ions is studied. Microwave plasma-enhanced chemical-vapor deposition is used for diamond growth. The single-crystal copper substrates were implanted either at room or elevated temperature with carbon ions prior to diamond nucleation. This procedure leads to the formation of a graphite film on the copper surface which greatly enhances diamond crystallite nucleation. A simple lattice model is constructed for diamond growth on graphite as 111 line (diamond) parallel to 0001 line (graphite) and 110 line (diamond) parallel to 1 1 -2 0 (graphite).

Ong, T. P.; Xiong, Fulin; Chang, R. P. H.; White, C. W.

1992-01-01

87

Tooth - abnormal shape  

MedlinePLUS

... many different conditions. Specific diseases can affect tooth shape, tooth color, time of appearance, or absence of teeth. ... any medical conditions that may cause abnormal tooth shape? At what age ... spacing)? What other symptoms are also present? Fillings, ...

88

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.

89

Nanosecond Pulsed Laser Processing of Ion Implanted Single Crystal Silicon Carbide Thin Layers  

NASA Astrophysics Data System (ADS)

The attractiveness of single crystal SiC in a variety of high power, high voltage, and high temperature device applications such as electric vehicles and jet engines is counteracted by the very high cost of substrates. Precision cutting of multiple micrometre thick SiC layers and transferring them to lower cost substrates would drive the cost down and allow expanding the use of single crystal SiC. In this study, laser beam processing has been utilized to exfoliate thin layers from a surface of single crystal SiC that was prepared with hydrogen and boron ion implantation. The layer thickness of 1 ?m has been achieved by ion implantation that formed voids and microcracks under the surface at a layer of 150 nm thick. High energy laser pulses provided the layer removal and its transfer to bonded Si substrate has been shown. Exfoliated surfaces and topography have been evaluated with Scanning Electron Microscopy. Furthermore, thermal modelling of pulse laser irradiation of implanted multi-layer SiC material has been conducted and temperature profiles are obtained at different peak pulse intensity settings to optimize exfoliation process parameters. It was found that laser exfoliation mechanism can be further improved by higher optical absorptance of defect rich layer obtained with boron ion implantation.

Özel, Tu?rul; Thepsonthi, Thanongsak; Amarasinghe, Voshadhi P.; Celler, George K.

90

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

91

In vitro and in vivo experimental studies on single crystal sapphire dental implants.  

PubMed

Successful attachment of the oral tissues to an endosseous dental implant relies in part on its chemical stability, nontoxic properties and maintenance of normal cell functions in the surrounding tissues. The aim of this study was therefore to investigate these 3 factors experimentally. The corrosion resistance of single crystal sapphire (alpha-Al2O3) implants was analysed with respect to the release of aluminium ions; no ions could be detected in the test solutions. The influence of single crystal sapphire on the behaviour of human epithelial cells and fibroblasts derived from biopsies of the oral mucosa, was studied. The cells were cultured in chemically defined or in low serum-containing media. Compared to the corresponding control cultures, no effects on cell morphology and growth characteristics were observed. Sapphire rods were inserted subcutaneously into rats and tissue responses were examined after 4, 8 and 12 weeks post-implantation. None or slight reactions were found in the tissues. The combined evaluation of these experimental approaches indicates that single crystal sapphire is a material well suited for biological implantation. PMID:1809399

Arvidson, K; Fartash, B; Moberg, L E; Grafström, R; Ericsson, I

1991-01-01

92

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

93

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

94

Silver cluster formation in implanted Al{sub 2}O{sub 3} single crystals  

SciTech Connect

Single crystals of sapphire were implanted at room temperature with 300 keV-Ag. The metal precipitate was characterized by a multitechnique approach including RBS, optical absorption and Raman spectroscopy. RBS measurements were used to determine the depth-profiles of the implanted ions. Ag depth profiles, derived from RBS are in good agreement with the results predicted by Monte Carlo simulations. Linear absorption spectroscopy has been used to characterize the effects of the ion fluence on the optical properties of the metal colloids in the UV-Vis region. The broad absorption band due to the surface plasmon resonance shows an appreciable red-shift when the fluence of bombarding ions increases. Raman scattering from acoustic vibrations of the silver clusters progressively shifts toward the laser frequency with increasing implantation dose. From low-frequency Raman spectra an evaluation of the average size of metal aggregates was derived.

Freire, F.L. Jr. [PUC-Rio, Rio de Janeiro (Brazil). Dept. de Fisica; Broll, N.; Mariotto, G. [Univ. di Trento (Italy)

1996-12-31

95

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

96

Monte Carlo simulation of ion implantation into single-crystal silicon including new models for electronic stopping and cumulative damage  

Microsoft Academic Search

The authors have developed a substantially improved physically based model for boron implantation into single-crystal silicon based on the Monte Carlo code MARLOWE. This model accounts for all relevant implant parameters and incorporates a local electron concentration-dependent electronic stopping model and a cumulative damage model. Good agreement with experimental profiles is obtained not only as a function of energy but

K. M. Klein; A. F. Tasch

1990-01-01

97

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

98

Single Bilateral Dexamethasone Implant in Addition to Panretinal Photocoagulation and Oral Azathioprine Treatment in IRVAN Syndrome  

PubMed Central

The idiopathic retinal vasculitis, aneurysms and neuroretinitis (IRVAN) syndrome is a disease characterized by multiple retinal macroaneurysms, neuroretinitis and peripheral capillary nonperfusion. Visual loss may result from either ischemia-related complications or macular involvement. Treatment is not always rewarding. We report a case with stage 2 IRVAN syndrome who was successfully treated with a single bilateral intravitreal dexamethasone implant in addition to panretinal photocoagulation and systemic azathioprine treatment. PMID:25802506

Saatci, Ali Osman; Ayhan, Ziya; Take?, Ömer; Yaman, Aylin; Bajin, F. Meltem Söylev

2015-01-01

99

Screw-retained crown restorations of single implants: A step-by-step clinical guide  

PubMed Central

This paper shows the clinical steps for preparing a screw-retained crown for the restoration of a single implant. Impression-taking using open-tray technique and delivery of the crown is presented in a step-by-step manner elucidated by detailed photographs. Furthermore, the advantages and disadvantages of screw-retained crowns are discussed in comparison with the cemented restorations. PMID:25512742

Assaf, Mohammad; Gharbyeh, Alaa’ Z. Abu

2014-01-01

100

Screw-retained crown restorations of single implants: A step-by-step clinical guide.  

PubMed

This paper shows the clinical steps for preparing a screw-retained crown for the restoration of a single implant. Impression-taking using open-tray technique and delivery of the crown is presented in a step-by-step manner elucidated by detailed photographs. Furthermore, the advantages and disadvantages of screw-retained crowns are discussed in comparison with the cemented restorations. PMID:25512742

Assaf, Mohammad; Abu Gharbyeh, Alaa' Z

2014-10-01

101

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients  

Microsoft Academic Search

OBJECTIVE: To describe the long term clinical outcome (up to 11 years)\\u000a after coronary stenting. DESIGN: A single centre observational study\\u000a encompassing 1000 consecutive patients with a first stent implantation\\u000a (1560 stents) between 1986 and 1996, who were followed for at least one\\u000a year with a median follow up of 29 months (range 12-132 months). RESULTS:\\u000a Up to July 1997

Brand van den M. J. B. M; Feyter de P. J; P. W. J. C. Serruys; D. P. Foley; Giessen van der W. J; Jaegere de P; Domburg van R. T; J. N. Hamburger

1999-01-01

102

PAC Studies of Implanted 111Ag in Single-Crystalline ZnO  

NASA Astrophysics Data System (ADS)

The local environment of implanted 111Ag ( t 1/2 = 7.45 d) in single-crystalline [0001] ZnO was evaluated by means of the perturbed angular correlation (PAC) technique. Following the 60 keV low dose (1 × 1013 cm-2) 111Ag implantation, the PAC measurements were performed for the as-implanted state and following 30 min air annealing steps, at temperatures ranging from 200 to 1050°C. The results revealed that 42% of the probes are located at defect-free SZn sites ( ? Q ˜ 32 MHz, ? = 0) in the as-implanted state and that this fraction did not significantly change with annealing. Moreover, a progressive lattice recovery in the near vicinity of the probes was observed. Different EFGs assigned to point defects were furthermore measured and a general modification of their parameters occurred after 600°C. The 900°C annealing induced the loss of 30% of the 111Ag atoms, 7% of which were located in regions of high defects concentration.

Rita, E.; Correia, J. G.; Wahl, U.; Alves, E.; Lopes, A. M. L.; Soares, J. C.

2004-11-01

103

Immediate placement of single implant simultaneously with immediate loading in a fresh socket associated to periapical infection: A clinical case report.  

PubMed

Early restoration of the masticatory function, phonatory and aesthetics is some of the current goals of the therapy based on endosseous implants. Facing the classic protocols of implant insertion, which recommend a period of several months between extraction and implant placement, alternatives have been developed that demonstrate that immediate implant placement after tooth extraction permits adequate osseointegration, even in those cases where there is a periapical disease. The immediate restoration of implants after placement is a possibility where aesthetic requirements are high. This article presents a case with immediate implant placement and immediate loading of a first upper premolar with prior periapical pathology due to a vertical fracture. The immediate prosthetic was performed using the extracted crown, which is adapted to be attached to a titanium temporary abutment using a resin cement. After a 4 month healing period work began on the final prosthetic crown. The screw crown was made of zirconium oxide with a covering feldspathic ceramic. At the 12-month follow-up, there were no mechanical or biological complications. The patient gave high satisfaction marks for the overall treatment, giving visual analogue scale score of nine. Immediate post-extraction implants have arisen as an alternative to traditional implants on completely healed bone. Their main aim is to reduce treatment time and number of surgical procedures, along with other objectives such as reduced bone re-absorption and improved aesthetics. Key words:Post-extraction implants, immediate loading prosthetic, implant-retained prosthesis, periapical disease, vertical fracture. PMID:25810833

Agustín-Panadero, Rubén; Serra-Pastor, Blanca; Chust-López, Cesar; Fons-Font, Antonio; Ferreiroa, Alberto

2015-02-01

104

Immediate placement of single implant simultaneously with immediate loading in a fresh socket associated to periapical infection: A clinical case report  

PubMed Central

Early restoration of the masticatory function, phonatory and aesthetics is some of the current goals of the therapy based on endosseous implants. Facing the classic protocols of implant insertion, which recommend a period of several months between extraction and implant placement, alternatives have been developed that demonstrate that immediate implant placement after tooth extraction permits adequate osseointegration, even in those cases where there is a periapical disease. The immediate restoration of implants after placement is a possibility where aesthetic requirements are high. This article presents a case with immediate implant placement and immediate loading of a first upper premolar with prior periapical pathology due to a vertical fracture. The immediate prosthetic was performed using the extracted crown, which is adapted to be attached to a titanium temporary abutment using a resin cement. After a 4 month healing period work began on the final prosthetic crown. The screw crown was made of zirconium oxide with a covering feldspathic ceramic. At the 12-month follow-up, there were no mechanical or biological complications. The patient gave high satisfaction marks for the overall treatment, giving visual analogue scale score of nine. Immediate post-extraction implants have arisen as an alternative to traditional implants on completely healed bone. Their main aim is to reduce treatment time and number of surgical procedures, along with other objectives such as reduced bone re-absorption and improved aesthetics. Key words:Post-extraction implants, immediate loading prosthetic, implant-retained prosthesis, periapical disease, vertical fracture.

Agustín-Panadero, Rubén; Serra-Pastor, Blanca; Chust-López, Cesar; Fons-Font, Antonio; Ferreiroa, Alberto

2015-01-01

105

Tooth formation - delayed or absent  

MedlinePLUS

Specific diseases can affect tooth shape, tooth color, time of appearance, or tooth absence. Delayed or absent tooth formation can result from many different conditions, including: Apert syndrome Cleidocranial ...

106

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

107

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

108

3D Statistical Models for Tooth Surface Reconstruction  

E-print Network

in the treatment of malocclusion [1], [2], identifying the optimal cutting plane for an implant [3] and selecting the outcome of orthognathic surgery with their patients [6]. Many dental and maxillofacial surgery a good knowledge of the shape of a given tooth is also extremely helpful in creating implants. Currently

Boyer, Edmond

109

Surface characterization of Cu-ion implanted single crystal and thin film ZnO for catalytic applications  

NASA Astrophysics Data System (ADS)

Single crystals and thin films of zinc oxide were implanted with copper ions in order to study the catalytic properties of a mixed Cu-ZnO system. ZnO is widely used as a catalyst in the methanol synthesis reaction, and copper has been noted to have a synergistic effect on the rates and yields of reaction. The samples were characterized by x-ray photoelectron spectroscopy (XPS) before and after implantation, and surface copper concentration in the implanted specimens was determined. Implanted samples were heated under oxidizing and reducing atmospheres and re-examined by XPS to determine the oxidation state of the implanted copper species. XPS results demonstrated that the oxidation state of the copper could be manipulated, although there was a corresponding decrease in the concentration of the surface copper ions, relative to temperature and time of heating.

Brodkin, J. S.; Chadwick, D.

1995-05-01

110

The central single implant in the edentulous mandible: improvement of function and quality of life. A report of 2 cases.  

PubMed

Implant-retained overdentures are a reliable treatment option for edentulous patients, especially when only few implants can be placed. Internationally, 2 implants are considered adequate to retain an overdenture in the edentulous mandible. However, for many patients, 2 implants can be cost-prohibitive. By means of 2 clinical cases, it is shown that the insertion of a single implant in the middle of the mandible might stabilize the prosthesis and improve the oral health quality of life and the chewing function. A ball attachment with a screw-activated matrix was used to retain the overdenture. Early clinical results are promising. However, before this method can be recommended for general clinical application, long- term clinical results are needed. PMID:19107261

Wolfart, Stefan; Braasch, Katja; Brunzel, Simone; Kern, Matthias

2008-01-01

111

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. PMID:25674313

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

112

Impedance analysis of secondary phases in a Co-implanted ZnO single crystal.  

PubMed

Co ions with 100 keV energy with a fluence of 1 × 10(15) cm(-2) are implanted into ZnO(0001) single crystals at 300 °C under vacuum. The resulting Co-implanted ZnO single crystals and the subsequent 750 °C and 900 °C annealed samples are analysed with respect to their structural, optical, electronic, magnetic and ac electrical properties. Photoluminescence and X-ray photoelectron spectroscopy results indicate the signatures of the Co(2+) state and its substitution at the tetrahedrally coordinated Zn-sites. X-ray diffraction and X-ray photoelectron spectroscopy identify the presence of the ZnCo2O4 and Co3O4 phases in the 900 °C annealed sample. By comparing the resistance response of the identified phases towards different magnetic environments, the impedance spectroscopy results successfully identify two magnetic phases (ZnCo2O4 and Co3O4) and a paramagnetic (CoZn) phase for the 750 °C and 900 °C annealed samples, implying the extrinsic nature of room temperature ferromagnetism. The observed ferromagnetism in each sample is not of single origin, instead the mutual effects of the secondary phases embedded in the paramagnetic host matrix are in competition with each other. PMID:24963819

Younas, M; Zou, L L; Nadeem, M; Naeem-ur-Rehman; Su, S C; Wang, Z L; Anwand, W; Wagner, A; Hao, J H; Leung, C W; Lortz, R; Ling, F C C

2014-08-14

113

Bacteremia Associated with Tooth Brushing and Dental Extraction  

PubMed Central

Background Antibiotic prophylaxis recommendations for the prevention of infective endocarditis are based in part on studies of bacteremia from dental procedures, but tooth brushing may pose a greater threat. The purpose of this study was to compare the incidence, duration, nature and magnitude of endocarditis-related bacteremia from single tooth extraction and tooth brushing, and to determine the impact of amoxicillin prophylaxis on single tooth extraction. Methods and Results In this double-blind, placebo-controlled study, 290 subjects were randomized to 1) tooth brushing, 2) single tooth extraction with amoxicillin prophylaxis, or 3) single tooth extraction with identical placebo. Blood was drawn for bacterial culturing and identification at six time points before, during and after these interventions. The focus of our analysis was on bacterial species reported to cause infective endocarditis. We identified 98 bacterial species, 32 of which are reported to cause endocarditis. Cumulative incidence of endocarditis-related bacteria from all 6 blood draws was 23%, 33% and 60% for the tooth brushing, extraction-amoxicillin and extraction-placebo groups, respectively (p<0.0001). Significant difference were identified among the three groups at draws 2, 3, 4 and 5 (all p<0.05). Amoxicillin resulted in a significant decrease in positive cultures (p<0.0001). Conclusions Although amoxicillin has a significant impact on bacteremia from a single tooth extraction, given the greater frequency for oral hygiene, tooth brushing may be a greater threat for individuals at risk for infective endocarditis. PMID:18541739

Lockhart, Peter B.; Brennan, Michael T.; Sasser, Howell C.; Fox, Philip C.; Paster, Bruce J.; Bahrani-Mougeot, Farah K.

2009-01-01

114

The local structure and ferromagnetism in Fe-implanted SrTiO{sub 3} single crystals  

SciTech Connect

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 Fe{sup 0} to Fe{sup 2+}/Fe{sup 3+} oxide. The STO single crystals were weak ferromagnets prior to implantation. The maximum saturation moment was obtained after our highest implantation dose of 2?×?10{sup 16} Fe atom/cm{sup 2}, which could be correlated with the metallic Fe{sup 0} phases in addition to the presence of O/Ti vacancies. After recrystallization annealing, the ferromagnetic response disappears. Iron oxide phases with Fe{sup 2+} and Fe{sup 3+} corresponding to this regime were identified and confirmed by calculations using Real Space Multiple Scattering program (FEFF9).

Lobacheva, O., E-mail: olobache@uwo.ca; Chavarha, M. [Department of Physics and Astronomy, The University of Western Ontario, London ON N6A 5B7 (Canada); Yiu, Y. M. [Department of Chemistry, The University of Western Ontario, London ON N6A 5B7 (Canada); Sham, T. K.; Goncharova, L. V. [Department of Physics and Astronomy, The University of Western Ontario, London ON N6A 5B7 (Canada); Department of Chemistry, The University of Western Ontario, London ON N6A 5B7 (Canada)

2014-07-07

115

Tooth Eruption without Roots  

PubMed Central

Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future. PMID:23345536

2013-01-01

116

Formation of optical barriers with excellent thermal stability in single-crystal sapphire by hydrogen ion implantation and thermal annealing  

Microsoft Academic Search

We report a study on the use of hydrogen ion implantation to form optical barriers with excellent thermal stability in single-crystal sapphire. Sapphire crystals are implanted with H ions of energies 0.2-1 MeV to doses 1016-1017 cm-2, followed by thermal annealing between 600-1200 °C. Prism coupling experiments and spectroscopic ellipsometry indicate the formation of an optical barrier with decreased refractive

William T. Spratt; Mengbing Huang; Chuanlei Jia; Lei Wang; Vimal K. Kamineni; Alain C. Diebold; Hua Xia

2011-01-01

117

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

118

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

119

Resin-bonded restorations: A strategy for managing anterior tooth loss in adolescence.  

PubMed

In children or adolescents with anterior tooth loss, space closure with the patient's own teeth should be considered as the first choice to avoid lifelong restorative needs. Thorough diagnostics and treatment planning are required when autotransplantation or orthodontic space closure is considered. If these options are not indicated and a single tooth implant restoration is considered, implant placement should be postponed until adulthood, particularly in young women and in patients with hyperdivergent skeletal growth pattern. A ceramic resin-bonded fixed dental prosthesis with 1 retainer is an excellent treatment solution for the interim period; it may also serve as a long-term restoration, providing that sound enamel structure is present, sufficient framework dimensions have been provided, adhesive cementation techniques have been meticulously applied, and functional contacts of the cantilever pontic avoided. In contrast, a resin-bonded fixed dental prosthesis with a metal framework and retentive preparation is indicated if the palatal enamel structure is compromised, interocclusal clearance is limited, splinting (such as after orthodontic treatment) is required, or more than 1 tooth has to be replaced. PMID:25702966

Zitzmann, Nicola U; Özcan, Mutlu; Scherrer, Susanne S; Bühler, Julia M; Weiger, Roland; Krastl, Gabriel

2015-04-01

120

The annealing behavior of ion-implanted single crystals of the type YBa 2Cu 3O x  

NASA Astrophysics Data System (ADS)

Recent measurements have shown that the structural disorder induced by the implantation of ions into high- Tc superconducting oxides of the type YBa 2Cu 3O x can lead to significant decomposition of the implanted region during subsequent thermal processing. We have used Rutherford backscattering spectrometry and ion channeling to examine the effects of ion implantation and thermal annealing on the near-surface composition of these materials. Our results indicate that the decomposition of the implanted region of YBa 2Cu 3O x single crystals is associated with Ba migration and occurs for ion doses above a definite threshold when thermal anneals are carried out at temperatures greater than 500 °C in a variety of atmospheres (O 2, O 2 + H 2O, Ar). Importantly, we have also observed that the implanted crystals can be annealed in O 2 at a temperature of 850 ° C with little decomposition of the implanted region occurring and that, under these conditions, the implantation-induced disorder is substantially removed.

McCallum, J. C.; White, C. W.; Boatner, L. A.

1989-04-01

121

The annealing behavior of ion-implanted single crystals of the type YBa2Cu3O(sub x)  

NASA Astrophysics Data System (ADS)

Recent measurements have shown that the structural disorder induced by the implantation of ions into high-T sub c superconducting oxides of the type YBa2Cu3O sub chi can lead to significant decomposition of the implanted region during subsequent thermal processing. We have used Rutherford backscattering spectrometry and ion channeling to examine the effects of ion implantation and thermal annealing on the near-surface composition of these materials. Our results indicate that the decomposition of the implanted region of YBa2Cu3O sub chi single crystals is associated with Ba migration and occurs for ion doses above a definite threshold when thermal anneals are carried out at temperatures greater than 500 degrees C in a variety of atmospheres (O2, O2 + H2O, Ar). Importantly, we have also observed that the implanted crystals can be annealed in O2 at a temperature of 850 C with little decomposition of the implanted region occurring and that, under these conditions, the implantation-induced disorder is substantially removed.

McCallum, J. C.; White, C. W.; Boatner, L. A.

1988-09-01

122

Modulation frequency discrimination with single and multiple channels in cochlear implant users.  

PubMed

Temporal envelope cues convey important speech information for cochlear implant (CI) users. Many studies have explored CI users' single-channel temporal envelope processing. However, in clinical CI speech processors, temporal envelope information is processed by multiple channels. Previous studies have shown that amplitude modulation frequency discrimination (AMFD) thresholds are better when temporal envelopes are delivered to multiple rather than single channels. In clinical fitting, current levels on single channels must often be reduced to accommodate multi-channel loudness summation. As such, it is unclear whether the multi-channel advantage in AMFD observed in previous studies was due to coherent envelope information distributed across the cochlea or to greater loudness associated with multi-channel stimulation. In this study, single- and multi-channel AMFD thresholds were measured in CI users. Multi-channel component electrodes were either widely or narrowly spaced to vary the degree of overlap between neural populations. The reference amplitude modulation (AM) frequency was 100 Hz, and coherent modulation was applied to all channels. In Experiment 1, single- and multi-channel AMFD thresholds were measured at similar loudness. In this case, current levels on component channels were higher for single-than for multi-channel AM stimuli, and the modulation depth was approximately 100% of the perceptual dynamic range (i.e., between threshold and maximum acceptable loudness). Results showed no significant difference in AMFD thresholds between similarly loud single- and multi-channel modulated stimuli. In Experiment 2, single- and multi-channel AMFD thresholds were compared at substantially different loudness. In this case, current levels on component channels were the same for single- and multi-channel stimuli ("summation-adjusted" current levels) and the same range of modulation (in dB) was applied to the component channels for both single- and multi-channel testing. With the summation-adjusted current levels, loudness was lower with single than with multiple channels and the AM depth resulted in substantial stimulation below single-channel audibility, thereby reducing the perceptual range of AM. Results showed that AMFD thresholds were significantly better with multiple channels than with any of the single component channels. There was no significant effect of the distribution of electrodes on multi-channel AMFD thresholds. The results suggest that increased loudness due to multi-channel summation may contribute to the multi-channel advantage in AMFD, and that overall loudness may matter more than the distribution of envelope information in the cochlea. PMID:25746914

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

2015-06-01

123

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

124

Deep level transient spectroscopic study of oxygen-implanted ZnO single crystal  

NASA Astrophysics Data System (ADS)

ZnO single crystal samples were implanted by oxygen with the energy of 150keV. After the pretreatment of hydrogen peroxide [1], Schottky contacts were fabricated with Au film deposited by thermal evaporation. Deep level defects were studied by deep level transient spectroscopy (DLTS). The activation energy of the 0.29eV deep trap was observed in the as-implanted sample and samples anneal at 350 ^oC , 650 ^oC and 750 ^oC. Three peaks were identified in the DLTS spectra of the 900 ^oC sample, with the activation energies of 0.11eV, 0.25eV and 0.37eV respectively. The thermal evolutions of the deep levels up to the temperature of 1200 ^oC were also investigated. [4pt] [1] Q. L. Gu, C. C. Ling, X. D. Chen, C. K. Cheng, A. M. C. Ng, C. D. Beling, S. Fung, A. B. Djurisi'c, L. W. Lu, G. Brauer and H. C. Ong, Appl. Phys. Lett. 90, 122101, (2007).

Ye, Ziran; Ding, Guangwei; Fan, Jincheng; Chung Ling, Chi

2011-03-01

125

Pulsed laser deposition of bioceramic thin films from human tooth  

Microsoft Academic Search

The possibility of pulsed laser deposition of thin films from human tooth targets was studied, since bioceramic thin film coatings on dental and orthopaedic implants may have their surface characteristics for biointegration improved. Pellets were pressed from tooth powder at different pressures and ablated with pulses of ArF (?=193 nm) and KrF (?=248 nm) excimer lasers with fluences up to 4.5 and

T. Smausz; B. Hopp; H. Huszár; Z. Tóth; G. Kecskeméti

2004-01-01

126

Immediate placement of implant into impacted maxillary canine extraction socket.  

PubMed

Impaction of a maxillary canine is common. Orthodontic realignment is not always the therapy of choice. Instead, the impacted tooth can be extracted and replaced by an implant. The replacement of a single tooth with an implant in the anterior maxilla is a topic of interest for clinicians because of its esthetic implications, mostly when immediate loading has been planned. This article describes a clinical case in which an impacted maxillary canine was replaced by an immediately restored osseointegrated implant. A 21-year-old woman with a palatally impacted maxillary canine and the corresponding primary tooth still remaining in the arch was treated. Both the primary and permanent teeth were surgically extracted. A conical-shaped blasted implant was immediately placed into the socket of the primary canine. A self-contained osseous defect remained on the palatal aspect and was filled with bovine bone mineral. The implant achieved excellent primary stability, so it was immediately restored with a provisional acrylic resin crown in light centric occlusion. After 6 months, the definitive metal-ceramic crown was placed. The therapy provided an excellent esthetic result, maintaining ideal soft tissue contours and papillary height. No signs of radiolucency were visible at the 1-year evaluation. The case presented supports the use of single implants for the replacement of extracted primary teeth, especially in areas where esthetics is a high priority. Furthermore, because the prosthetic restoration was done immediately, the overall time needed to restore the patient was considerably reduced in comparison with the time required for the conventional approach. PMID:17370664

Cardaropoli, Daniele; Debernardi, Cesare; Cardaropoli, Giuseppe

2007-02-01

127

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses  

PubMed Central

Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up. Key words:Immediate implants, delayed implants, peri-implant health, success rate. PMID:24316712

Pellicer-Chover, Hilario; Peñarrocha-Oltra, David; Bagán, Leticia; Fichy-Fernandez, Antonio J.; Canullo, Luigi

2014-01-01

128

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

129

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

130

Early complications of permanent pacemaker implantation: no difference between dual and single chamber systems  

Microsoft Academic Search

OBJECTIVE--To evaluate the incidence of intraoperative and early postoperative complications (up to two months after implant) of endocardial permanent pacemaker insertion in all patients under-going a first implant at a referral centre. METHODS--Prospective evaluation of all endocardial pacemaker implantation procedures performed from April 1992 to January 1994 carried out by completion of standard audit form at implant. Patients' demographic data,

R. K. Aggarwal; D. T. Connelly; S. G. Ray; J. Ball; R. G. Charles

1995-01-01

131

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. PMID:25667729

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

2014-01-01

132

Stress Analysis on Single Cobalt/Chrome Prosthesis with a 15mm Cantilever placed over 10/13/15mm length implants. A simulated photoelastic model study.  

PubMed

Abstract Purpose: The aim of study was to assess the stress around 10/13/15 mm implants in the mandibular area with a 15 mm cantilevered acrylic resin coated prostheses following the application force, using the photoelasticity method. Materials and Methods: Three photoelastic mandibular models were created containing 10, 13, and 15 mm implants in length and 3.75 mm in diameter. The implants had bore internal hex connections and were placed parallel to the inter-mental region. Abutments with 1-mm high cuffs were placed over the implants, and a single cobalt/chrome metallic prosthesis with a 15-mm cantilever coated with thermoplastic acrylic resin was placed on top. Loads of 1.0 and 3.0 bars were applied, and the images were photographed and assessed by photoelasticity method. Results: The greatest stress levels were observed for the 10-mm implants. The stress pattern was the same regardless of the length of the implants; only the magnitude of the stress along the implant body revealed changes. Increased implant length played a role in reducing the stress on the investigated area of the model, and the 15-mm implants exhibited the best performance in regard to stress distribution. The highest stress levels were found in the implants closest to the cantilever and the central implant. Conclusions: The longest implants were more favorable in regard to the stress distribution on the peri-implant support structures in 15mm cantilevered prosthesis under loads. PMID:24914673

Gastaldo, José Fábio Guastelli; Pimentel, Angelica Castro; Gomes, Maria Helena; Sendyk, Wilson Roberto; Lagana, Dalva Cruz

2014-06-10

133

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

134

DEALING WITH DENTAL IMPLANT FAILURES  

PubMed Central

An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options. When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them. PMID:19089213

Levin, Liran

2008-01-01

135

Blistering and cracking of LiTaO3 single crystal under helium ion implantation  

NASA Astrophysics Data System (ADS)

Blistering and cracking in LiTaO3 surface are investigated after 200-keV helium ion implantation and subsequent post-implantation annealing. Rutherford backscattering/channeling is used to examine the lattice damage caused by ion implantation. Blistering is observed through optical microscopy in a dynamic heating process. Atomic force microscopy and scanning electron microscopy measurements are used to detect the LiTaO3 surface morphology. Experimental results show that blistering and flaking are dependent on implantation fluence, beam current, and also annealing temperature. We speculate that the surface cracking of He+-implanted LiTaO3 results from the implantation-induced stress and compression.

Ma, Changdong; Lu, Fei; Ma, Yujie

2015-03-01

136

Analysis of mechanical behavior of implant-supported prostheses in the anterior maxilla: analysis by speckle pattern interferometry  

NASA Astrophysics Data System (ADS)

The use of implants to rehabilitation of total edentulous, partial edentulous or single tooth is increasing, it is due to the high rate of success that this type of treatment present. The objective of this study was to analyze the mechanical behavior of different positions of two dental implants in a rehabilitation of 4 teeth in the region of maxilla anterior. The groups studied were divided according the positioning of the implants. The Group 1: Internal Hexagonal implant in position of lateral incisors and pontic in region of central incisors; Group 2: Internal Hexagonal implant in position of central incisors and cantilever of the lateral incisors and Group3 - : Internal Hexagonal implants alternate with suspended elements. The Electronic Speckle Pattern Interferometry (ESPI) technique was selected for the mechanical evaluation of the 3 groups performance. The results are shown in interferometric phase maps representing the displacement field of the prosthetic structure.

Corrêa, Cássia B.; Ramos, Nuno V.; Monteiro, Jaime; Vaz, Luis G.; Vaz, Mario A. P.

2012-10-01

137

Bone Substitutes for Peri-Implant Defects of Postextraction Implants  

PubMed Central

Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration. PMID:24454377

Santos, Pâmela Letícia; Gulinelli, Jéssica Lemos; Telles, Cristino da Silva; Betoni Júnior, Walter; Chiacchio Buchignani, Vivian; Queiroz, Thallita Pereira

2013-01-01

138

Productivity Improvement for the SHX--SEN's Single-Wafer High-Current Ion Implanter  

SciTech Connect

Equipment productivity is a critical issue for device fabrication. For ion implantation, productivity is determined both by ion current at the wafer and by utilization efficiency of the ion beam. Such improvements not only result in higher fabrication efficiency but also reduce consumption of both electrical power and process gases. For high-current ion implanters, reduction of implant area is a key factor to increase efficiency. SEN has developed the SAVING system (Scanning Area Variation Implantation with Narrower Geometrical pattern) to address this opportunity. In this paper, three variations of the SAVING system are introduced along with discussion of their effects on fab productivity.

Ninomiya, Shiro; Ochi, Akihiro; Kimura, Yasuhiko; Yumiyama, Toshio; Kudo, Tetsuya; Kurose, Takeshi; Kariya, Hiroyuki; Tsukihara, Mitsukuni; Ishikawa, Koji; Ueno, Kazuyoshi [SEN Corporation, 1501, Imazaike, Saijo, Ehime, 799-1362 (Japan)

2011-01-07

139

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

140

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

141

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 ...

142

Tooth Colored Fillings  

MedlinePLUS

... materials and both the enamel and dentin. Restorative dentistry recreates a tooth that not only looks natural ... Using Nature as a Guide In the past, dentistry focused on creating “stronger” teeth by using very ...

143

Clinical evaluation of ceramic implant abutments in anterior restorations.  

PubMed

The development of new high strength ceramic abutments can enhance the overall aesthetic outcome of an implant-supported prosthesis. This study was to compare the clinical application of alumina and zirconia ceramic implant abutments in the anterior region. Twenty-three consecutive patients requiring single-tooth implants in the anterior region were randomized to receive either an alumina ceramic abutment (CeraAdapt) or a zirconia ceramic abutment. All-ceramic (IPS-Empress 2) crowns were then fabricated and cemented over the abutments with composite cement. Peri-implant mucosal health and bone levels were evaluated by the gingival index and radiographs at 2-week and 1-year follow-up. Aesthetic outcomes as well as technical problems with the restorations were evaluated during the observation period from 12 to 48 months after functional loading. A total of 17 alumina ceramic abutments and 18 zirconia ceramic abutments were evaluated. No patients dropped out during the study period. Eighteen out of the 23 patients maintained good function throughout the study. The median observation period was 21 months. Ceramic crown loosening was found in two restorations at 1-week and 2-years respectively after insertion. One ceramic crown fractured at 1 week after insertion. At 1-year follow-up, mean marginal bone loss around implants was 1.2 +/- 0.5 mm and the peri-implant mucosa in relation to abutment or crown was healthy with a mean gingival score of 0.6 +/- 0.2. All patients were satisfied with the final aesthetic outcome. However, two alumina abutments fractured after two years of loading. In conclusion, both ceramic abutments have shown a favourable biological response and aesthetic outcome; however, zirconia abutments with their superior mechanical properties might be better for supporting single-tooth implant restorations in the aesthetic zone. PMID:22073456

Chen, Zhuo-Fan; Nang, Pow Ho; Wang, Yan; Luo, Zhi-Bin

2008-06-01

144

View Single Post Thread: [medgadget] Implantable RFID Tag to Wirelessly Monitor GERD 06-04-2007, 08:37 AM #1 (permalink)  

E-print Network

, flexible RFID chip to the esophagus, where it remains until removed by a physician. The chip, about twoView Single Post Thread: [medgadget] Implantable RFID Tag to Wirelessly Monitor GERD 06-04-2007, 08] Implantable RFID Tag to Wirelessly Monitor GERD Imagine pushing a button at the first substernal burning

Chiao, Jung-Chih

145

Transillumination defects following in-the-bag single-piece intraocular lens implantation and trabeculectomy with mini-shunt.  

PubMed

An 80-year-old woman of mixed ethnicity developed significant iris transillumination defects following phacoemulsification with in-the-bag implantation of a single-piece hydrophobic acrylic intraocular lens (IOL) and trabeculectomy with insertion of an Express mini-shunt. With the exception of modest anterior chamber shallowing in the first few weeks postoperatively, the surgery and postoperative course were uneventful. The observed iris defects are thought to have been caused by contact between the IOL-capsule complex and the posterior iris during shallowing of the anterior chamber. No other cases in the peer-reviewed literature have identified iris defects secondary to implantation of a single-piece monofocal hydrophobic acrylic IOL when the optic and haptics remained entirely within the capsular bag. PMID:23149100

Rosenthal, Kenneth J; Venkateswaran, Nandini

2013-01-01

146

A single-chip signal processing and telemetry engine for an implantable 96-channel neural data acquisition system  

Microsoft Academic Search

A fully implantable neural data acquisition system is a key component of a clinically viable cortical brain–machine interface. We present the design and implementation of a single-chip device that serves the processing needs of such a system. Our device processes 96 channels of multi-unit neural data and performs all digital processing necessary for bidirectional wireless communication. The implementation utilizes a

Michael Rizk; Iyad Obeid; Stephen H Callender; Patrick D Wolf

2007-01-01

147

A single-chip signal processing and telemetry engine for an implantable 96-channel neural data acquisition system  

Microsoft Academic Search

A fully implantable neural data acquisition system is a key component of a clinically viable cortical brain-machine interface. We present the design and implementation of a single-chip device that serves the processing needs of such a system. Our device processes 96 channels of multi-unit neural data and performs all digital processing necessary for bidirectional wireless communication. The implementation utilizes a

Michael Rizk; Iyad Obeid; Stephen H. Callender; Patrick D. Wolf

2007-01-01

148

Magnetic and Structural Studies in Co and Mn-implanted SrTiO3 Single Crystals  

Microsoft Academic Search

Micro Raman and static magnetization data on manganese or cobalt-implanted (at 3 or 5 at.%) strontium titanate (Mn,Co):SrTiO3 single crystals are presented. Micro Raman results reveal a cubic perovskite structure at 300 K with no evidence of any secondary phase. All samples show ferromagnetism both at 300 K and at 10 K. Moreover, micro Raman spectra at low temperature reveal

P. Galinetto; A. Casiraghi; M. C. Mozzati; C. B. Azzoni; David P. Norton; Lynn A Boatner; V. A. Trepakov

2008-01-01

149

Outcomes following cochlear implantation for patients with single-sided deafness, including those with recalcitrant Ménière's disease  

PubMed Central

Objective Compare pre and postoperative performance in patients undergoing cochlear implantation (CI) for unilateral severe-to-profound sensorineural hearing loss (single-sided deafness, SSD). Study design IRB-approved, prospective Setting Tertiary center Patients Twenty-nine patients have undergone CI for SSD. SSD was due to Ménière's disease (MD) in 10 subjects; these also suffered from recalcitrant vertigo spells and in these 10 patients along with 2 others the CI was placed simultaneous with a labyrinthectomy. Intervention(s) CI with or without labyrinthectomy. Main outcome measure(s) CNC word and AzBio sentences in quiet were administered to the implanted ear. A multiple-loudspeaker sound localization test was administered in the bilateral listening condition. All data were collected pre-operatively and 3, 6, 12-months post-operatively with post-operative data available for 19 subjects. Additionally, a tinnitus handicap questionnaire is administered pre- and 12-months post-operatively. Results CNC word and AzBio sentence scores showed improvement in the implanted ear. Sound localization appeared to improve in an experience dependent fashion in some patients. Most patients reported diminished tinnitus following cochlear implantation. All patients undergoing labyrinthectomy experienced resolution of vertigo attacks. Conclusions CI restores auditory function to the deafened ear. Additionally, the binaural input appears to improve sound localization for most patients. In patients with severe hearing loss and recalcitrant vertigo attacks due to MD, simultaneous labyrinthectomy and CI effectively relieves vertigo attacks and improves auditory function. PMID:24232066

Hansen, Marlan R.; Gantz, Bruce J.; Dunn, Camille

2013-01-01

150

Photoluminescence of Au - formed in 12CaO · 7Al 2O 3 single crystal by Au +-implantation  

NASA Astrophysics Data System (ADS)

Au + ion implantation with fluences from 1 × 10 14 to 3 × 10 16 cm -2 into 12CaO · 7Al 2O 3 (C12A7) single crystals was carried out at a sample temperature of 600 °C. The implanted sample with the fluence of 1 × 10 15 cm -2 exhibited photoluminescence (PL) bands peaking at ˜3.1 and ˜2.3 eV at ?150 K when excited by He-Cd laser (325 nm). This was the first observation of PL from C12A7. These two PL bands are possibly due to intra-ionic transitions of an Au - ion having the electronic configuration of 6 s2, judged from their similarities to those reported on Au - ions in alkali halides. However, when the concentration of the implanted Au ions exceeded the theoretical maximum value of anions encaged in C12A7 (˜2.3 × 10 21 cm -3), surface plasmon absorption appeared in the optical absorption spectrum, suggesting Au colloids were formed at such high fluences. These observations indicate that negative gold ions are formed in the cages of C12A7 by the Au + implantation if an appropriate fluence is chosen.

Miyakawa, M.; Kamioka, H.; Hirano, M.; Kamiya, T.; Hosono, H.

2006-09-01

151

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

152

Charcot-Marie-Tooth Disease  

MedlinePLUS

... Charcot-Marie-Tooth Disease? Charcot-Marie-Tooth disease (CMT) is one of the most common inherited neurological ... in 2,500 people in the United States. CMT, also known as hereditary motor and sensory neuropathy ( ...

153

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

154

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

155

Formation of optical barriers with excellent thermal stability in single-crystal sapphire by hydrogen ion implantation and thermal annealing  

NASA Astrophysics Data System (ADS)

We report a study on the use of hydrogen ion implantation to form optical barriers with excellent thermal stability in single-crystal sapphire. Sapphire crystals are implanted with H ions of energies 0.2-1 MeV to doses 1016-1017 cm-2, followed by thermal annealing between 600-1200 °C. Prism coupling experiments and spectroscopic ellipsometry indicate the formation of an optical barrier with decreased refractive index around the projected range of H ions in sapphire. The refractive index reduction is found to increase with annealing temperatures, reaching a maximum of ˜3.2% following annealing at 1200 °C. The correlation of the structural properties with the formation of optical barriers and their thermal stability in sapphire crystals, is duscussed.

Spratt, William T.; Huang, Mengbing; Jia, Chuanlei; Wang, Lei; Kamineni, Vimal K.; Diebold, Alain C.; Xia, Hua

2011-09-01

156

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

157

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

158

The Wisdom Tooth  

PubMed Central

Physicians may often wonder about the basis on which dentists advocate removal of third molars. This article outlines indications for removal and for leaving the tooth in place. It also describes postoperative experiences according to the nature of the extractions. ImagesFig. 2Fig. 3Fig. 4Fig. 5 PMID:21289716

Speck, John E.

1981-01-01

159

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

160

I Lost My Tooth!  

ERIC Educational Resources Information Center

Highlights the Internet Schoolhouse Web site and outlines a cross-curriculum (language arts, geography, social studies, health, art, and math) lesson plan for a grades K-3 telecommunications project in which students gather data about lost teeth and share tooth-fairy legends. Lists required hardware, software, and other materials and describes…

Boehm, Diann

1997-01-01

161

Microflora around teeth and dental implants  

PubMed Central

Background: When an implant is exposed to oral cavity, its surface gets colonized by micro-organisms. The aim of this study is to comparatively assess the microbiological parameters in sulci around the teeth and the crowns supported by dental implants. Materials and Methods: In this prospective, cross-sectional study, 34 partially edentulous patients aged between 40 and 50 years with total 50 anterior maxillary single implants with cemented crowns (depth of sulci <4 mm) and 34 similar teeth in the same jaw of the same patients were included. Excluded were the patients with compromised systemic and periodontal health and smoking habits. None of the patients had used any antimicrobial mouthwashes during at least two weeks before the study. All of the implants (ITI) were at least 6 months in place covered by definitive prostheses. Samples of gingival sulci were taken around teeth with paper cone and transported to Stuart transport medium. Samples were cultured and examined by a dark field microscope and eight laboratory tests were performed to determine the micro-organisms The data were evaluated statistically using Chi-square test (?=0.05). Results: Six anerobic bacteria found in teeth and implants sulci were Gram-positive cocci, Gram-negative cocci, Prevotella, Porphyromonas gingivalis, Bacteroid Fragilis and Fusobacterium. Gram-positive cocci and Gram-negative cocci had maximum and minimum percentage frequency in the two groups, respectively. There were no significant differences between the two groups (P value >0.05). Conclusion: The present study indicated that microflora in implant sulci is similar to the tooth sulci, when the depth of sulci is normal (<4 mm). As a result, implants’ susceptibility to inflammation is the same as teeth. PMID:22623941

Shahabouee, Mohammad; Rismanchian, Mansour; Yaghini, Jaber; Babashahi, Akram; Badrian, Hamid; Goroohi, Hossein

2012-01-01

162

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

163

Photoluminescence from Au ion-implanted nanoporous single-crystal 12CaO•7Al2O3  

NASA Astrophysics Data System (ADS)

Implantation of Au+ ions into a single crystalline 12CaO•7Al2O3 (C12A7) was performed at high temperatures with fluences from 1×1014 to 3×1016cm-2 . This material is composed of positively charged sub-nanometer-sized cages compensated by extra-framework negatively charged species. The depth profile of concentrations of Au species was analyzed using Rutherford backscattering spectrometry. The measured optical spectra and ab initio embedded cluster calculations show that the implanted Au species are stabilized in the form of negative Au- ions below the fluences of ˜1×1016cm-2 (Au volume concentration of ˜2×1021cm-3 ). These ions are trapped in the cages and exhibit photoluminescence (PL) bands peaking at 3.05 and 2.34eV at temperatures below 150K . At fluences exceeding ˜3×1016cm-2 , the implanted Au atoms form nano-sized clusters. This is manifested in quenching of the PL bands and creation of an optical absorption band at 2.43eV due to the surface plasmon of free carriers in the cluster. The PL bands are attributed to the charge transfer transitions (Au0+e-?Au-) due to recombination of photo-excited electrons (e-) , transiently transferred by ultraviolet excitation into a nearby cages, with Au0 atoms.

Miyakawa, Masashi; Kamioka, Hayato; Hirano, Masahiro; Kamiya, Toshio; Sushko, Peter V.; Shluger, Alexander L.; Matsunami, Noriaki; Hosono, Hideo

2006-05-01

164

Magnetic and Structural Studies in Co- and Mn-implanted SrTiO3 Single Crystals  

SciTech Connect

Micro Raman and static magnetization data on manganese or cobalt-implanted (at 3 or 5 at.%) strontium titanate (Mn,Co):SrTiO3 single crystals are presented. Micro Raman results reveal a cubic perovskite structure at 300 K with no evidence of any secondary phase. All samples show ferromagnetism both at 300 K and at 10 K. Moreover, micro Raman spectra at low temperature reveal the presence of polar ordering, which allow to consider the investigated materials as possible host matrices for multiferroic phenomena. Obtained results are discussed in connection to supplementary outcomes derived by content, optical absorption and electron paramagnetic resonance (EPR) measurements.

Galinetto, P. [Universita di Pavia, Italy; Casiraghi, A. [CNISM and Dipartimento di Fisica A. Volta, Universit di Pavia, Pavia, Italy; Mozzati, M. C. [CNISM and Dipartimento di Fisica A. Volta, Universit di Pavia, Pavia, Italy; Azzoni, C. B. [CNISM and Dipartimento di Fisica A. Volta, Universit di Pavia, Pavia, Italy; Norton, David P. [University of Florida; Boatner, Lynn A [ORNL; Trepakov, V. A. [Institute of Physics AS CR, Na Slovance 2, Czech Republic

2008-02-01

165

Transradial artery Palmaz-Schatz coronary stent implantation: results of a single-center feasibility study.  

PubMed

The purpose of this study was to evaluate the feasibility and safety of implantation of unsheathed Palmaz-Schatz coronary stents introduced via the radial artery. Anticoagulation after coronary stenting carries the risk of vascular complications if large-bore guiding catheters are introduced via the femoral artery. These complications have serious local sequelae and lead to suboptimal anticoagulation and prolonged hospitalization. By combining 6F guiding catheters and low-profile dilatation catheters mounted with Palmaz-Schatz stents, smaller vessels such as the radial artery can be selected as the entry site. It is hypothesized that with this technique major puncture site-related complications rarely occur because hemostasis is easily achieved and because no veins and nerves are near this artery. With the double blood supply to the hand, radial artery occlusion is well tolerated. In 100 consecutive patients, stent implantation was attempted for 122 lesions in 104 vessels. Immediately after stent implantation and final angiography, the introducer sheath was withdrawn and intense anticoagulation and mobilization initiated. The radial artery puncture site was studied by two-dimensional and Doppler ultrasound. Successful stent implantation via the radial artery was achieved in 96 patients. In 2 patients, arterial puncture failed but was followed by successful stenting via another entry site. In 1 patient, stent implantation was achieved with a stent delivery system via the femoral artery after a failed attempt to cross the lesion with a bare stent via the radial approach, complicated by groin bleeding requiring transfusions and vascular surgery.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7611104

Kiemeneij, F; Laarman, G J

1995-07-01

166

The rationale for the introduction of implant dentistry into the dental curriculum.  

PubMed

This paper provides arguments for the introduction of implant dentistry into the undergraduate curriculum. The survival of teeth is very high when disease is diagnosed and treated properly and maintenance is taken care of. Nevertheless, tooth replacements by fixed and removable prostheses are highly prevalent. It is expected that dentists will face a dramatically increased need to care for elderly patients and partially edentulous patients. Hence, the demand for implant reconstructions will be substantial and more appropriately trained and competent health professionals will be needed. Increasing demands of the patient regarding aesthetics and function will influence the demands for implant therapy. The improvement of oral function and subjective chewing comfort, the preservation of tooth structures or existing reconstructions and the replacement of missing, strategically important teeth are major indications for implant placement. From both a biological and an economical point of view, the single tooth replacement with an implant is the first choice in situations with no or minimally restored neighbouring teeth compared with conventional bridgework. Stability of full dentures represent a major problem especially for the mandible. It is well documented that placement of two implants supporting an overdenture substantially improve chewing capacity, increase quality of life and is a simple and cost-effective treatment thus rendering such treatment a 'standard of care' procedure. There is no doubt that dental students should learn to incorporate the indication of oral implants in their overall treatment planning. Therefore, they will have to understand the basic aspects of healing and tissue integration, basic biomechanical and material science principles as well as surgical and prosthetic techniques. They will have to be able to monitor continuously the peri-implant tissues, render appropriate supportive therapy and cope with biological and technical complications. While it is evident that the surgical procedure per se may require additional competence, the remainder of the aspects mentioned should be taught in the dental curriculum. This should include the attribution of responsibility for maintenance of implants and handling of biological and technical complications. Moreover, it is desirable to include the surgical technique for implant placement for 'straightforward' cases into the dental curriculum. The levels and limitations to which the various aspects of implant dentistry and related skills are to be taught are determined by the academic community. Obviously, ethical and legal aspects of implant dentistry should not be forgotten. PMID:19281511

Lang, N P; De Bruyn, H

2009-02-01

167

ImplantsHydroxylapatite coated dental implants  

Microsoft Academic Search

Objective To evaluate the clinical effectiveness, common complications and maintenance associated with hydroxylapatite (HA) coated cylindrical implants when used to support single crowns.Design A prospective medium term clinical study of the Calcitek HA-coated implant.Setting Implant placement, crown fabrication and follow-up procedures were carried out at the Leeds Dental Institute, between 1990 and 1998.Subjects and method 26 patients (33 implants) participated

Peter Briggs

1999-01-01

168

Restoration of the Severely Decayed Tooth Using Crown Lengthening with Simultaneous Tooth-Preparation  

PubMed Central

This clinical case describes a treatment approach that combines, in a single appointment, a crown lengthening procedure and the final crown preparation for the restoration of a severely decayed tooth. This approach allows for a more accurate placement of the crown margin in relation to the bone crest while reducing treatment time. PMID:20396453

Park, Jun-Beom

2010-01-01

169

Comparison of Success of Implants versus Endodontically Treated Teeth  

Microsoft Academic Search

Implants verses root canal therapy is a current controversy in dentistry. The purpose of this investigation was to compare the success of each treatment, with minimal subjective grading. Outcome was determined by clinical chart notes and radiographs. Failure was defined as removal of the implant or tooth. Uncertain findings for implants were defined as mobility class I or greater, radiographic

James Porter Hannahan; Paul Duncan Eleazer

2008-01-01

170

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

171

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

172

Cochlear Implants  

MedlinePLUS

... Medical Devices Products and Medical Procedures Implants and Prosthetics Cochlear Implants Cochlear Implants View movie of the ... More in Products and Medical Procedures Implants and Prosthetics Cochlear Implants What is a Cochlear Implant? Benefits ...

173

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

174

Radioactive labeling in the study of abrasion of hard tooth tissue  

Microsoft Academic Search

Labeling the surface of hard tooth tissue samples by the nuclear recoil effect in radioactive decay was applied to study abrasion\\u000a caused by abrasive components of tooth-pastes.222Rn and its short-lived decay products were implanted into the surface in vacuum. For this purpose irradiation was applied\\u000a to sample placed very close to thin226Ra source. Measuring the activity before and after abrasion

A. Gosman; D. Houšová; J. Koní?ek; L. Doležalová

1998-01-01

175

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. PMID:25540668

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

2014-01-01

176

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

177

Multistage Electrotherapy Delivered Through Chronically-Implanted Leads Terminates Atrial Fibrillation With Lower Energy Than a Single Biphasic Shock  

PubMed Central

Objectives The goal of this study was to develop a low-energy, implantable device–based multistage electrotherapy (MSE) to terminate atrial fibrillation (AF). Background Previous attempts to perform cardioversion of AF by using an implantable device were limited by the pain caused by use of a high-energy single biphasic shock (BPS). Methods Transvenous leads were implanted into the right atrium (RA), coronary sinus, and left pulmonary artery of 14 dogs. Self-sustaining AF was induced by 6 ± 2 weeks of high-rate RA pacing. Atrial defibrillation thresholds of standard versus experimental electrotherapies were measured in vivo and studied by using optical imaging in vitro. Results The mean AF cycle length (CL) in vivo was 112 ± 21 ms (534 beats/min). The impedances of the RA–left pulmonary artery and RA–coronary sinus shock vectors were similar (121 ± 11 ? vs. 126 ± 9 ?; p = 0.27). BPS required 1.48 ± 0.91 J (165 ± 34 V) to terminate AF. In contrast, MSE terminated AF with significantly less energy (0.16 ± 0.16 J; p < 0.001) and significantly lower peak voltage (31.1 ± 19.3 V; p < 0.001). In vitro optical imaging studies found that AF was maintained by localized foci originating from pulmonary vein–left atrium interfaces. MSE Stage 1 shocks temporarily disrupted localized foci; MSE Stage 2 entrainment shocks continued to silence the localized foci driving AF; and MSE Stage 3 pacing stimuli enabled consistent RA–left atrium activation until sinus rhythm was restored. Conclusions Low-energy MSE significantly reduced the atrial defibrillation thresholds compared with BPS in a canine model of AF. MSE may enable painless, device-based AF therapy. PMID:24076284

Janardhan, Ajit H.; Gutbrod, Sarah R.; Li, Wenwen; Lang, Di; Schuessler, Richard B.; Efimov, Igor R.

2014-01-01

178

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

179

Should retention of a tooth be an important goal of dentistry? How do you decide whether to retain and restore a tooth requiring endodontic treatment or to extract and if possible replace the tooth?  

PubMed

Whether a questionable tooth should be treated endodontically or extracted, is still a dilemma clinicians encounter every day. With advances in technology such as implantology, deciding whether or not to save a tooth is still not clear. Local site-specific factors and patient-related factors that may affect the longevity of a particular tooth should be considered in preparing the treatment plan. Long-term success rates for root canal therapy and implant-supported crowns demonstrate similar outcomes. A choice between these alone is not sufficient in the decision-making process. Only following a systematic evaluation of the reasons for and against tooth retention as directed by each individual case, can the best option be decided. PMID:25850364

Zachar, Jessica J

2015-04-01

180

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

181

LETTER TO THE EDITOR: High Curie-temperature ferromagnetism in cobalt-implanted single-crystalline rutile  

NASA Astrophysics Data System (ADS)

The ion implantation technique has been used to fabricate a Co-rich layer in rutile: single-crystalline TiO2 substrates were heavily irradiated by Co+ ions with energy of 40 keV. The magnetic properties of as-prepared and post-annealed samples were studied by both inductive and Faraday magnetometry as well as ferromagnetic resonance (FMR). A ferromagnetic Curie temperature as high as 700 K was measured in our samples. The analysis of the magnetic hysteresis loop, the temperature dependence of the saturation magnetization, and strong out-of-plane anisotropy of the FMR spectra allow us to suppose that the origin of the macroscopic high-temperature ferromagnetism is the exchange interaction mediated by oxygen vacancies.

Khaibullin, R. I.; Tagirov, L. R.; Rameev, B. Z.; Ibragimov, Sh Z.; Yildiz, F.; Aktas, B.

2004-10-01

182

Functional Tooth Restoration by Allogeneic Mesenchymal Stem Cell-Based Bio-Root Regeneration in Swine  

PubMed Central

Our previous proof-of-concept study showed the feasibility of regenerating the dental stem cell-based bioengineered tooth root (bio-root) structure in a large animal model. Here, we used allogeneic dental mesenchymal stem cells to regenerate bio-root, and then installed a crown on the bio-root to restore tooth function. A root shape hydroxyapatite tricalcium phosphate scaffold containing dental pulp stem cells was covered by a Vc-induced periodontal ligament stem cell sheet and implanted into a newly generated jaw bone implant socket. Six months after implantation, a prefabricated porcelain crown was cemented to the implant and subjected to tooth function. Clinical, radiological, histological, ultrastructural, systemic immunological evaluations and mechanical properties were analyzed for dynamic changes in the bio-root structure. The regenerated bio-root exhibited characteristics of a normal tooth after 6 months of use, including dentinal tubule-like and functional periodontal ligament-like structures. No immunological response to the bio-roots was observed. We developed a standard stem cell procedure for bio-root regeneration to restore adult tooth function. This study is the first to successfully regenerate a functional bio-root structure for artificial crown restoration by using allogeneic dental stem cells and Vc-induced cell sheet, and assess the recipient immune response in a preclinical model. PMID:23363023

Wei, Fulan; Song, Tieli; Ding, Gang; Xu, Junji; Liu, Yi; Liu, Dayong; Fan, Zhipeng; Zhang, Chunmei

2013-01-01

183

Implant-supported full-mouth reconstruction Malo Implant Bridge.  

PubMed

This article describes the clinical techniques and laboratory procedures for fabricating a predictable Malo Implant Bridge involving application of an occlusal screw-retained implant superstructure on the basis of the All-on-4 concept. The Malo Implant Bridge features a removable occlusal screw-retained superstructure; fabrication of the framework with a computer-aided design/computer-aided manufacturing system allowing accurate adaptation; and use of the final tooth position model with guide temporary crowns allowing easy porcelain build-up and satisfying the patient's esthetic concerns. PMID:22856035

Kodama, Taishi

2012-06-01

184

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

185

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

186

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

187

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

188

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

189

Cochlear Implants  

MedlinePLUS

Cochlear Implants Cochlear Implants Patient Health Information News media interested in covering the latest from AAO-HNS/F can ... only with a cochlear implant. How do cochlear implants work? Cochlear implants bypass damaged hair cells and ...

190

Breast Implants  

MedlinePLUS

... in women with breast implants. Outline the regulatory history of breast implants in the United States. Encourage reporting ... Medical Procedures Implants and Prosthetics Breast Implants Regulatory History of Breast Implants in the U.S. Saline-Filled Breast ...

191

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

192

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

193

Hemisection of a fused tooth.  

PubMed

Fusion is a developmental anomaly which occurs due to a union of 1 or more adjacent teeth during morphodifferentiation of the dental germs. The present case report presents the hemisection of a maxillary central incisor fused with a supernumerary tooth. A 10-year-old boy was referred to clinic with the chief complaint of the presence of a large anterior tooth. Intraoral and radiographic investigations indicated fusion between the left central incisor and a supernumerary tooth. The fused tooth was separated with a diamond bur, and the supernumerary tooth was extracted. The left central incisor was restored with composite resin and the diastema between the maxillary central incisors was closed with orthodontic treatment. The left central incisor was still healthy after a follow-up examination period of 24 months. An ideal overjet and overbite relation was achieved at the end of the orthodontic treatment. Hemisection can be considered as an appropriate treatment alternative for a permanent tooth fused with a supernumerary tooth. PMID:17656128

Cetinbas, Tugba; Halil, Suleyman; Akcam, Mehmet Okan; Sari, Saziye; Cetiner, Serap

2007-10-01

194

Esthetic management of double tooth associated with talon cusp using a laminate veneer.  

PubMed

Double tooth and talon cusp are tooth shape anomalies with rare co-occurrences in a single tooth. Double tooth is a developmental anomaly that leads to the eruption of fused teeth and may contribute to compromised esthetics, pain, caries, and tooth crowding. Talon cusp is a rare developmental extra cusp-like projection on the cingulum area that may cause functional and esthetic problems. Differential diagnosis of these anomalies may be complicated. A multidisciplinary approach for the esthetic and functional rehabilitation of double teeth is important. Various treatment methods have been described in the literature for the different types and morphological variations of double teeth. The purpose of this paper is to report the case of an unusual combination of double tooth and talon cusp on a permanent maxillary incisor and describe its esthetic and functional rehabilitation using a porcelain laminate veneer. PMID:25514262

Cordeiro, Wayne José Batista; do Couto, Cintia Fernandes; Barros, Renata Nunes; Zarranz, Laila; Jorge, Mônica Zacharias; de Gouvêa, Cresus Vínicius Depes

2015-01-01

195

A novel root analogue dental implant using CT scan and CAD/CAM: selective laser melting technology.  

PubMed

Direct laser metal forming (DLMF) is a new technique 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. Modern computed tomography (CT) acquisition and 3D image conversion, combined with the DLMF process, allows the fabrication of custom-made, root-analogue implants (RAI), perfect copies of the radicular units that need replacing. This report demonstrates the successful clinical use of a custom-made, root-analogue DLMF implant. CT images of the residual non-restorable root of a right maxillary premolar were acquired and modified with specific software into a 3D model. From this model, a custom-made, root-analogue, DLMF implant was fabricated. Immediately after tooth extraction, the root-analogue implant was placed in the extraction socket and restored with a single crown. At the 1-year follow-up examination, the custom-made implant showed almost perfect functional and aesthetic integration. The possibility of fabricating custom-made, root-analogue DLMF implants opens new interesting perspectives for immediate placement of dental implants. PMID:22377004

Figliuzzi, M; Mangano, F; Mangano, C

2012-07-01

196

Cost-effectiveness of Anterior Implants versus Fixed Dental Prostheses  

PubMed Central

For the restoration of an anterior missing tooth, implant-supported single crowns (ISCs) or fixed dental prostheses (FDPs) are indicated, but it is not clear which type of restoration is more cost-effective. A self-selected trial was performed with 15 patients with ISCs and 11 with FDPs. Patient preferences were recorded with visual analog scales before treatment, 1 month following restoration, and then annually. Quality-adjusted tooth years (QATYs) were estimated by considering the type of reconstruction for replacing the missing tooth and its effect on the adjacent teeth. A stochastic cost-effectiveness model was developed using Monte Carlo simulation. The expected costs and QATYs were summarized in cost-effectiveness acceptability curves. ISC was the dominant strategy, with a QATY increase of 0.01 over 3 years and 0.04 over 10 years with a higher probability of being cost-effective. While both treatment options provided satisfactory long-term results from the patient’s perspective, the lower initial costs, particularly laboratory fees, were responsible for the dominance of ISCs over FDPs. PMID:24158338

Zitzmann, N.U.; Krastl, G.; Weiger, R.; Kühl, S.; Sendi, P.

2013-01-01

197

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

E-print Network

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 crystal diamond using a focused ion beam and in situ lift-out. The method results in samples approximately

Florida, University of

198

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

NASA Astrophysics Data System (ADS)

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

199

Rapid maxillary expansion assisted by palatal mini-implants in adolescents - Preliminary study.  

PubMed

Our preliminary clinical study compares the transverse skeletal and dento-alveolar modifications occurring after rapid maxillary expansion with purely dental anchorage or with dental anchorage assisted by palatal mini-implants, in endognathic adolescents aged 12 to 17. Nine patients were treated by means of tooth- and implant-supported expansion, and 7 others by means of a purely tooth-borne expander. The changes, 4months after expansion, were measured on impressions and front-view X-rays in the 2 groups, and on three-dimensional X-rays for 6 patients treated by tooth- and implant-supported expansion. In our sample, tooth- and implant-supported expansion preserved the alveolar bone of 14/24 and gave rise to less buccal tipping of 16/26 than purely tooth-borne expansion. PMID:25665914

Chane-Fane, Caroline; Darqué, François

2015-03-01

200

Charcot-Marie-Tooth Disease  

MedlinePLUS

Charcot-Marie-Tooth disease (CMT) is a group of genetic nerve disorders. It is named after the three doctors who first identified it. In the United States, CMT affects about 1 in 2,500 people. CMT ...

201

The Early Years: Tooth Time  

NSDL National Science Digital Library

One of the big changes in childhood is the loss of "baby" teeth, beginning around age five. Children often say, "I'm a big kid now. I lost my tooth!" This event is longed for, feared, and celebrated. Tooth care is much on children's (and their parents') minds as they learn that this is it--the new teeth growing in must last them the rest of their lives. This article includes a corresponding activity.

Peggy Ashbrook

2006-03-01

202

Minimally invasive treatment of soft tissue deficiency around an implant-supported restoration in the esthetic zone: modified VISTA technique case report.  

PubMed

The horizontal and vertical soft tissue dimension around an implant-supported restoration in the maxillary anterior is one of the determining factors for achieving an esthetic result. In this case report, the patient presented with a deficiency in both dimensions around a single-tooth implanted-supported restoration in the anterior maxilla. The soft tissue defects were augmented with a connective tissue graft that was placed underneath the buccal peri-implant tissue using a frenum access incision and a supraperiosteal tunneling approach (modified vestibular Incision supraperiosteal tunnel access [VISTA] technique). This novel technique resulted in an increase in tissue height and width, which suggests its potential use around implant-supported restorations. PMID:23510339

Lee, Chun-Teh; Hamalian, Techkouhie; Schulze-Späte, Ulrike

2015-02-01

203

Patient satisfaction with oral implant rehabilitation: evaluation of responses to a questionnaire  

PubMed Central

Summary Aim This pilot study evaluated patients’ experience of oral surgical and prosthetic procedures as well as their opinions regarding function, aesthetics, comfort, and satisfaction with treatment outcomes. Materials and methods Forty-nine subjects treated with oral implants completed questionnaires comprising 44 questions. Three questionnaires were used related to implant-supported single-tooth, fixed implant-supported prostheses and implant-retained overdentures. The questions related to demographic data (age, sex, employment, marital status and educational level), the source of information, the reason they underwent implant treatment, the discomfort related to all phases of treatment, and their functional and aesthetic satisfaction. Results Most of the patients (53.8%) were employed and had received a high school certificate or a university diploma. Patients heard about implants from various sources, including referring dentists (55.8%), relatives and friends (23.1%), and television, radio and the Internet (17.3%). The main reasons for choosing implant treatment were restoring lost teeth (35,5%), following dentist’s advice (33,3%), improving stability of the removable denture (15.4%), eating habits (13.5%) and aesthetics (1.9%). Most patients considered that the procedure took a long time (44.2%) but was not traumatic (62.5%). Pain was almost absent in most cases (64.5%) and swelling, when present, was generally moderate (48.1%) and seldom was marked (17.3%). Patients were very satisfied about the aesthetics (82.7%) and function (94.2%), and considered the implant prosthesis to be part of themselves (84.6%). Most of the patients considered the implant prostheses to be easy to clean (73.1%), and would repeat the treatment if necessary (86.5%) and recommend it to other people (94.2%). Conclusions Although the present study is limited by the small sample, the outcomes suggest that oral implant rehabilitation meets patients’ needs and aesthetic demands. PMID:22238708

Annibali, Susanna; Vestri, Anna Rita; Pilotto, Annalisa; La Monaca, Gerardo; Di Carlo, Stefano; Cristalli, Maria Paola

2011-01-01

204

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

205

Modulatory effects by neodymium-doped yttrium aluminum garnet laser on fibroblast attachment to single rooted tooth surfaces following ultrasonic scaling and root planning: An in vitro study  

PubMed Central

Context: One of the most important goals of periodontal therapy is connective tissue reattachment to previously diseased root surfaces. In the recent years, laser therapy has been considered as an important tool in improving the treatment of periodontal disease. Aims: To evaluate the neodymium-doped yttrium aluminum garnet (Nd: YAG) lasers effects on root surfaces affected by periodontal disease and compare this treatment with scaling and root planning (SRP) in terms of fibroblast attachment. Materials and Methods: A sample of 30 single-rooted human teeth extracted because of advanced periodontal disease was used in this study. Sixty specimens obtained by longitudinal sectioning were randomly divided in three groups. Group A control (untreated); Group B SRP; Group C laser (Nd: YAG) and ultrasonic scaling. All specimens were incubated with fibroblast suspension and then fixed and observed under scanning electron microscope. Results: With a median of 8, the control group (Group A) exhibited the least number of total fibroblasts among all the three groups. The laser and scaling - treated group (Group C) showed the highest number of fibroblasts (median = 49, mean ± standard deviation [SD] = 48.28 ± 17.18), followed by SRP only (Group B, median = 22, mean ± SD = 22.24 ± 8.67). Conclusions: Nd: YAG laser irradiation at specific energy densities can be used as a useful tool to condition the root surfaces, enhancing fibroblast attachment. Hence aiding in re-establishment of the connective tissue attachment to the root surfaces of previously diseased teeth.

Negi, Shanta; Krishnamurthy, Malathi; Ganji, Kiran Kumar; Pendor, Sunil

2015-01-01

206

Case study of a post-lingually deafened child with a UCH/RNID single channel cochlear implant.  

PubMed

In November 1987, a post-lingually deafened eight-year old became the first child to receive a cochlear implant in Britain. The case aroused considerable controversy and the following paper examines the decision to implant the child, the difficulties experienced and the favourable outcome of the procedure to date. PMID:2607196

Booth, C L; Read, T E; Archbold, S; Dyar, D; Morgan, C; Gray, R F

1989-01-01

207

Clinical measurement of tooth wear: Tooth wear indices  

PubMed Central

Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification corresponds to a different process with specific clinical features. Classifications made so far have no accurate prevalence data because the indexes do not necessarily measure a specific etiology, or because the study populations can be diverse in age and characteristics. Tooth wears (attrition, erosion and abrasion) is perceived internationally as a growing problem. However, the interpretation and comparison of clinical and epidemiological studies, it is increasingly difficult because of differences in terminology and the large number of indicators/indices that have been developed for the diagnosis, classification and monitoring of the loss of dental hard tissue. These indices have been designed to identify increasing severity and are usually numerical, none have universal acceptance, complicating the evaluation of the true increase in prevalence reported. This article considers the ideal requirements for an erosion index. A literature review is conducted with the aim of analyzing the evolution of the indices used today and discuss whether they meet the clinical needs and research in dentistry. Key words:Tooth wear, tooth wear indices, attrition, erosion, abrasion, abfraction. PMID:24558525

López-Frías, Francisco J.; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Llamas-Carreras, José M.

2012-01-01

208

Factors affecting the willingness to pay for implants: A study of patients in Riyadh, Saudi Arabia  

PubMed Central

Background: One of the factors that dissuade patients needing tooth replacement from choosing dental implants is the prohibitive cost. Willingness to pay (WTP) is a useful tool to determine the ideal cost of an expensive procedure. Aim: The aim of this study was to study the factors that influence the willingness to pay (WTP) among patients attending a private clinic and compare them to those attending a government setup. Materials and Methods: A total of 100 patients (38 male, 62 female) who had one or more missing teeth were presented with different cost-benefit scenarios and then asked if they were willing to pay the median cost of a single implant in Riyadh city. The mean WTP price was compared using the one way-ANOVA, factors which could possibly influence patients’ WTP were grouped together in a Binomial logistic regression model. Results: Of the 100 individuals surveyed 67% said they would be willing to pay the median price for the placement of an implant. A comparison of socio-demographic factors showed that significant differences were found between gender, income groups and setting of the clinic in the mean WTP price of the patients (P < 0.05). We also found that there was a significant difference in the mean WTP price between groups with regard to the area of the missing tooth, the patients’ perception of their oral health and the their desire to want an implant (P < 0.05). Conclusion: The majority of the patients surveyed were willing to pay the median price for an implant. Willingness to pay (WTP) is a multifactorial variable which is significantly influenced by the income of the patient, the setting of the clinic and the gender; the most significant factor being the acceptability of the implant to the patient. PMID:23559948

Al Garni, Bishi; Pani, Sharat Chandra; AlMaaz, Adel; Al Qeshtaini, Ehsan; Abu-Haimed, Hamad; Al Sharif, Khalid

2012-01-01

209

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

210

Bacterial diversity of periodontal and implant-related sites detected by the DNA Checkerboard method  

Microsoft Academic Search

The aim of this study was to compare the microbial composition of the subgingival biofilm from teeth and implant sulci in\\u000a relation to contents originating from internal parts of the implant, abutment and implant prosthesis. Twenty subgingival biofilm\\u000a samples from the mesial and distal aspects of each tooth\\/implant and 29 samples from the internal parts of titanium implants,\\u000a abutments and

C. do Nascimento; N. Monesi; I. Y. Ito; J. P. M. Issa; R. F. de Albuquerque Junior

211

The effect of a single remote injection of statin-impregnated poly (lactic- co-glycolic acid) microspheres on osteogenesis around titanium implants in rat tibia  

Microsoft Academic Search

The aim of this study was to evaluate the effects of newly developed injectable poly (lactic-co-glycolic acid) (PLGA) microspheres containing fluvastatin on osteogenesis around titanium implants in the rat tibia. After confirmation of the sustained-release profile of fluvastatin from the microspheres by an in vitro assay, the microspheres were administered to the back skin of the rats by a single

Tomohiro Masuzaki; Yasunori Ayukawa; Yasuko Moriyama; Yohei Jinno; Ikiru Atsuta; Yoichiro Ogino; Kiyoshi Koyano

2010-01-01

212

Esthetic Outcomes in Relation to Implant-Abutment Interface Design Following a Standardized Treatment Protocol in a Multicenter Randomized Controlled Trial- A Cohort of 12 Cases at 1-Year Follow-up.  

PubMed

The design of an implant-abutment interface may have an impact on the peri-implant soft tissue esthetics. In an ongoing randomized controlled trial (RCT) with 141 participants, the authors evaluated the peri-implant tissue responses around three different implant-abutment interface designs used to replace single teeth in the esthetic zone. The aim of this report is to describe the treatment protocol utilized in this ongoing RCT by (1) demonstrating in detail a clinical case treated under this protocol and (2) reporting peri-implant soft tissue responses in a cohort of 12 representative cases from the RCT at 1-year follow-up. Male and female adults requiring single implants in the anterior maxilla were enrolled in the RCT according to the study protocol. Five months following any required extraction and/or socket bone grafting/ridge augmentation, one of the following three implant-abutment interfaces was placed and immediately provisionalized: (1) conical interface (CI; OsseoSpeed, Dentsply Implants), n = 4; (2) flat-to-flat interface (FI; NobelSpeedy Replace, Nobel Biocare), n = 4; or (3) platform-switch interface (PS; NanoTite Certain Prevail, Biomet 3i), n = 4. Twelve weeks later, definitive crowns were delivered. Throughout the treatment, peri-implant buccal gingival zenith height and mesial/distal papilla height were measured on stereotactic device photographs, and pink esthetic scores (PES) were determined. The demographics of the participants in each of the three implant-abutment interface groups were very similar. All 12 study sites had ideal ridge form with a minimum width of 5.5 mm following implant site development performed according to the described treatment protocol. Using this treatment protocol for single-tooth replacement in the anterior maxilla, the clinicians were able to obtain esthetic peri-implant soft tissue outcomes with all three types of implant-abutment interface designs at 1-year follow-up as shown by the Canfield data and PES. The proposed treatment protocol for single-tooth replacement in the esthetic zone provides a reliable method to obtain and assess the esthetic outcome as a function of implant-abutment interface design and is now in its fifth year of follow-up. PMID:25738335

McGuire, Michael K; Scheyer, Todd; Ho, Daniel K; Stanford, Clark M; Feine, Jocelyne S; Cooper, Lyndon F

2015-01-01

213

[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

214

Coping with cracked tooth syndrome.  

PubMed

Cracked tooth syndrome typically poses a diagnostic challenge for the dentist. Symptoms include tenderness to biting on certain foods, often poorly localized, and occasional thermal sensitivity. Knowing where to look for this entity, especially in the mandibular molar region, can be especially helpful. Treatment of the tooth depends on the degree of pulpal involvement and the extent of the crack. Cuspal coverage is required of all cracked posterior teeth that are retainable. Root canal therapy is included if symptoms persist or if pulpal pathosis exists at the outset. Cracks extending beyond the osseous crest indicate a poor prognosis. Armed with this knowledge, the dentist can overcome many cracked tooth dilemmas, resulting in satisfaction for both patient and practitioner alike. PMID:9540698

Benenati, F W

1996-01-01

215

21 CFR 872.3920 - Porcelain tooth.  

Code of Federal Regulations, 2012 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device...

2012-04-01

216

21 CFR 872.3920 - Porcelain tooth.  

Code of Federal Regulations, 2010 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device...

2010-04-01

217

21 CFR 872.3920 - Porcelain tooth.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device...

2013-04-01

218

21 CFR 872.3920 - Porcelain tooth.  

Code of Federal Regulations, 2014 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device...

2014-04-01

219

Learning about Charcot-Marie-Tooth Disease  

MedlinePLUS

... Charcot-Marie-Tooth disease? Charcot-Marie-Tooth disease (CMT) is an inherited neurological disease characterized by a ... limbs, fingers, and toes. The first sign of CMT is generally a high arched foot or gait ...

220

Safety controversies in tooth bleaching.  

PubMed

Tooth bleaching using peroxide-based materials is an effective procedure in dentistry. Studies provide evidence on the safety of bleaching by dental professionals. However, concerns and controversy remain regarding the safety of bleaching systems that do not involve dental professionals, especially those available at mall kiosks, salons, spas, and cruise ships. Bleaching causes tooth sensitivity and/or gingival irritation in a significant portion of patients. Bleaching requires proper examination, diagnosis, and treatment plan, which can be performed appropriately only by dental professionals; therefore, involvement of dental professionals in bleaching is necessary to maximize the efficacy and minimize potential risks. PMID:21473992

Li, Yiming

2011-04-01

221

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

222

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

223

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

224

Surgical Management of Fractured Orthodontic Mini- Implant- A Case Report  

PubMed Central

The idea of absolute anchorage has always been an elusive goal for clinicians. Orthodontic mini-implants or temporary anchorage devices allow tooth movements previously thought to be impossible or difficult. Although extensive literature exists on use of temporary anchorage devices, their failures have been hardly focused upon, especially implant fracture. The following case report describes successful management of fractured orthodontic mini-implant. PMID:25738088

Jain, Anoop; Sumra, Nida

2015-01-01

225

Rare periodontal ligament drainage for periapical inflammation of an adjacent tooth: a case report and review of the literature.  

PubMed

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

226

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

227

What Are Tooth Preservation Kits?  

MedlinePLUS

... or teen loses a permanent tooth, it's a dental emergency. Permanent teeth have the best chance of survival if replaced ... dentist right away or go to a nearby emergency room that has a dental service. Reviewed by: Steven Dowshen, MD Date reviewed: ...

228

Erosive tooth wear in children.  

PubMed

Erosive tooth wear in children is a common condition. Besides the anatomical differences between deciduous and permanent teeth, additional histological differences may influence their susceptibility to dissolution. Considering laboratory studies alone, it is not clear whether deciduous teeth are more liable to erosive wear than permanent teeth. However, results from epidemiological studies imply that the primary dentition is less wear resistant than permanent teeth, possibly due to the overlapping of erosion with mechanical forces (like attrition or abrasion). Although low severity of tooth wear in children does not cause a significant impact on their quality of life, early erosive damage to their permanent teeth may compromise their dentition for their entire lifetime and require extensive restorative procedures. Therefore, early diagnosis of erosive wear and adequate preventive measures are important. Knowledge on the aetiological factors of erosive wear is a prerequisite for preventive strategies. Like in adults, extrinsic and intrinsic factors, or a combination of them, are possible reasons for erosive tooth wear in children and adolescents. Several factors directly related to erosive tooth wear in children are presently discussed, such as socio-economic aspects, gastroesophageal reflux or vomiting, and intake of some medicaments, as well as behavioural factors such as unusual eating and drinking habits. Additionally, frequent and excessive consumption of erosive foodstuffs and drinks are of importance. PMID:24993274

Carvalho, Thiago S; Lussi, Adrian; Jaeggi, Thomas; Gambon, Dein L

2014-01-01

229

Cochlear Implants.  

ERIC Educational Resources Information Center

This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

Clark, Catherine; Scott, Larry

230

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

231

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

232

The impact of transcatheter aortic valve implantation on left ventricular performance and wall thickness – single-centre experience  

PubMed Central

Introduction Transcatheter aortic valve implantation (TAVI) is a treatment alternative for the elderly population with severe symptomatic aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR). Aim To assess the impact of TAVI on echocardiographic parameters of left ventricular (LV) performance and wall thickness in patients subjected to the procedure in a single-centre between 2009 and 2013. Material and methods The initial group consisted of 170 consecutive patients with severe AS unsuitable for SAVR. Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 21.73 ±12.42% and mean age was 79.9 ±7.5 years. Results The TAVI was performed in 167 (98.2%) patients. Mean aortic gradient decreased significantly more rapidly after the procedure (from 58.6 ±16.7 mm Hg to 11.9 ±4.9 mm Hg, p < 0.001). The LV ejection fraction (LVEF) significantly increased in both short-term and long-term follow-up (57 ±14% vs. 59 ±13%, p < 0.001 and 56 ±14% vs. 60 ±12%, p < 0.001, respectively). Significant regression of interventricular septum diameter at end-diastole (IVSDD) and end-diastolic posterior wall thickness (EDPWth) was noted in early (15.0 ±2.4 mm vs. 14.5 ±2.3 mm, p < 0.001 and 12.7 ±2.1 mm vs. 12.4 ±1.9 mm, p < 0.028, respectively) and late post-TAVI period (15.1 ±2.5 mm to 14.3 ±2.5 mm, p < 0.001 and 12.8 ±2.0 mm to 12.4 ±1.9 mm, p < 0.007, respectively). Significant paravalvular leak (PL) was noted in 21 (13.1%) patients immediately after TAVI and in 13 (9.6%) patients in follow-up (p < 0.001). Moderate or severe mitral regurgitation (msMR) was seen in 24 (14.9%) patients from the initial group and in 19 (11.8%) patients after TAVI (p < 0.001). Conclusions The TAVI had an immediate beneficial effect on LVEF, LV walls thickness, and the incidence of msMR. The results of the procedure are comparable with those described in other centres.

Szyma?ski, Piotr; D?browski, Maciej; Zakrzewski, Dariusz; Micha?ek, Piotr; Or?owska-Baranowska, Ewa; El-Hassan, Kamal; Chmielak, Zbigniew; Witkowski, Adam; Hryniewiecki, Tomasz

2015-01-01

233

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

234

Palatal implants in the treatment of obstructive sleep apnea: a randomised, placebo-controlled single-centre trial.  

PubMed

Palatal implants have been used to treat snoring and mild to moderate obstructive sleep apnea (OSA). Two previous controlled trials have published conflicting results regarding the effects of palatal implants on objective outcome measures, although they both could demonstrate superiority over placebo. The aim of the present study was to assess the effects of palatal implants in patients with mild to moderate sleep apnea in a randomised, placebo-controlled trial. Twenty-two patients with mild to moderate OSA (AHI 18 ± 5, BMI 28 ± 3, age 51 ± 13 years) due to palatal obstruction were enrolled in this randomised, double-blind, placebo-controlled trial. Respiratory parameters and sleep efficiency (evaluated by polysomnography), snoring (evaluated by the bed partner), and daytime sleepiness (evaluated by ESS) were assessed before and 90 days after surgery. One patient in each group did not show up for follow-up. The AHI, HI and LSAT showed statistically significant improvement in the treatment group (p < 0.05). Snoring as rated by bed partners also showed statistically significant improvement within the treatment group (p = 0.025). There was no statistical difference when comparing the means of the treatment group with the placebo group. There were no peri- or post-operative complications and no extrusions during the follow-up period. The study supports the idea that palatal implants lead to a reduction in respiratory events in patients with mild to moderate OSA, although a statistically significant superiority of palatal implants over placebo could not be demonstrated in this trial. PMID:22228439

Maurer, J T; Sommer, J U; Hein, G; Hörmann, K; Heiser, C; Stuck, Boris A

2012-07-01

235

Tunable Band-Stop Plasmonic Filter Based on Symmetrical Tooth-Shaped Waveguide Couples  

NASA Astrophysics Data System (ADS)

A simple plasmonic filter with symmetrical tooth-shaped waveguides is proposed and investigated by using finite element method. It is found that the structure with a single symmetrical tooth-shaped waveguide couple can realize a tunable band-stop filter. Attributed to cascaded symmetrical tooth-shaped waveguide couples, the structure can achieve a flat band-stop response with no intensity variation over the transmission spectrum. And the central wavelength of the stopband linearly increases with the simultaneous increasing of depths of waveguides. Moreover, reduced structure size can be achieved by controlling the dielectric constant of the medium.

Cui, Luna; Song, Gang; Yu, Li; Lang, Peiling; Xiao, Jinghua

2013-06-01

236

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

237

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

238

The homology and phylogeny of chondrichthyan tooth enameloid.  

PubMed

A systematic SEM survey of tooth microstructure in (primarily) fossil taxa spanning chondrichthyan phylogeny demonstrates the presence of a superficial cap of single crystallite enameloid (SCE) on the teeth of several basal elasmobranchs, as well as on the tooth plates of Helodus (a basal holocephalan). This suggests that the epithelial-mesenchymal interactions required for the development of enameloid during odontogenesis are plesiomorphic in chondrichthyans, and most likely in toothed gnathostomes, and provides phylogenetic support for the homology of chondrichthyan and actinopterygian enameloid. Along the neoselachian stem, we see a crownward progression, possibly modulated by heterochrony, from a monolayer of SCE lacking microstructural differentiation to the complex triple-layered tooth enameloid fabric of neoselachians. Finally, the occurrence of fully-differentiated neoselachian enameloid microstructure (including compression-resistant tangle fibered enameloid and bending-resistant parallel fibered enameloid) in Chlamydoselachus anguineus, a basal Squalean with teeth that are functionally "cladodont," is evidence that triple-layered enameloid microstructure was a preadaption to the cutting and gouging function of many neoselachian teeth, and thus may have played an integral role in the Mesozoic radiation of the neoselachian crown group. PMID:17146771

Gillis, J Andrew; Donoghue, Philip C J

2007-01-01

239

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

240

Consideration of Moving Tooth Load in Gear Crack Propagation Predictions  

NASA Technical Reports Server (NTRS)

Robust gear designs consider not only crack initiation, but crack propagation trajectories for a fail-safe design. In actual gear operation, the magnitude as well as the position of the force changes as the gear rotates through the mesh. A study to determine the effect of moving gear tooth load on crack propagation predictions was performed. Two-dimensional analysis of an involute spur gear and three-dimensional analysis of a spiral-bevel pinion gear using the finite element method and boundary element method were studied and compared to experiments. A modified theory for predicting gear crack propagation paths based on the criteria of Erdogan and Sih was investigated. Crack simulation based on calculated stress intensity factors and mixed mode crack angle prediction techniques using a simple static analysis in which the tooth load was located at the highest point of single tooth contact was validated. For three-dimensional analysis, however, the analysis was valid only as long as the crack did not approach the contact region on the tooth.

Lewicki, David G.; Handschuh, Robert F.; Spievak, Lisa E.; Wawrzynek, Paul A.; Ingraffea, Anthony R.

2001-01-01

241

Contribution of Mesenchymal Proliferation in Tooth Root Morphogenesis  

PubMed Central

In mouse tooth development, the roots of the first lower molar develop after crown formation to form 2 cylindrical roots by post-natal day 5. This study compared the morphogenesis and cellular events of the mesial-root-forming (MRF) and bifurcation-forming (BF) regions, located in the mesial and center of the first lower molar, to better define the developmental mechanisms involved in multi-rooted tooth formation. We found that the mesenchyme in the MRF showed relatively higher proliferation than the bifurcation region. This suggested that spatially regulated mesenchymal proliferation is required for creating cylindrical root structure. The mechanism may involve the mesenchyme forming a physical barrier to epithelial invagination of Hertwig’s epithelial root sheath. To test these ideas, we cultured roots in the presence of pharmacological inhibitors of microtubule and actin polymerization, nocodazole and cytochalasin-D. Cytochalasin D also inhibits proliferation in epithelium and mesenchyme. Both drugs resulted in altered morphological changes in the tooth root structures. In particular, the nocodazole- and cytochalasin-D-treated specimens showed a loss of root diameter and formation of a single-root, respectively. Immunolocalization and three-dimensional reconstruction results confirmed these mesenchymal cellular events, with higher proliferation in MRF in multi-rooted tooth formation. PMID:24155265

Sohn, W.-J.; Choi, M.-A.; Yamamoto, H.; Lee, S.; Lee, Y.; Jung, J.-K.; Jin, M.-U.; An, C.-H.; Jung, H.-S.; Suh, J.-Y.; Shin, H.-I.; Kim, J.-Y.

2014-01-01

242

Tooth eruption: theories and facts.  

PubMed

The mechanisms of tooth eruption (i.e., the answer to the question of how and why teeth erupt) has been a matter of long historical debate. This review focuses on human and other mammalian teeth with a time- and spacewise limited period of eruption and analyzes recent observations and experimental data on dogs, rats, primates, and humans in a framework of basic biological parameters to formulate a guiding theory of tooth eruption. Acknowledging basic parameters (i.e., that teeth move in three-dimensional space, erupt with varying speed, and arrive at a functional position that in inheritable) eliminates a number of previously held theories and favors those that accommodate basic parameters, such as alveolar bone remodeling in association with root elongation, with possible correction factors in the form of cementum apposition and periodontal ligament formation. We have critically analyzed, summarized, and integrated recent findings associated with preeruptive movements of developing teeth, the intraosseous stage of premolar eruption in dogs, molar eruption in rodents, and premolar and molar eruption in primates. The variable speeds of eruption are particularly important. We conclude with basic principles of tooth eruption--that is, the type of signals generated by the dental follicle proper, the conditions under which teeth are moved and the clinical understanding to be derived from this knowledge. PMID:8769674

Marks, S C; Schroeder, H E

1996-06-01

243

Effects of human relaxin on orthodontic tooth movement and periodontal ligaments in rats  

PubMed Central

Introduction The rate-limiting step in orthodontic treatment is often the rapidity with which teeth move. Using biological agents to modify the rate of tooth movement has been shown to be effective in animals. Relaxin is a hormone present in both males and females. Its main action is to increase the turnover of fibrous connective tissues. Thus, relaxin might increase the amount and rate of tooth movement through its effect on the periodontal ligament (PDL). The purpose of this study was to measure the effect of relaxin on orthodontic tooth movement and PDL structures. Methods Bilateral orthodontic appliances designed to tip maxillary molars mesially with a force of 40 cN were placed in 96 rats. At day 0, the animals were randomized to either relaxin or vehicle treatment. Twelve rats in each group were killed at 2, 4, 7, and 9 days after appliance activation. Cephalograms were taken at appliance placement and when the rats were killed. Tooth movement was measured cephalometrically in relation to palatal implants. Fractal analysis and visual analog scale assessments were used to evaluate the effect of relaxin on PDL fiber organization at the tension sites in histologic sections. The in-vitro testing for PDL mechanical strength and tooth mobility was performed by using tissue from an additional 20 rats that had previously received the same relaxin or vehicle treatments for 1 or 3 days (n = 5). Results Both groups had statistically significant tooth movement as functions of time. However, relaxin did not stimulate significantly greater or more rapid tooth movement. Fractal and visual analog scale analyses implied that relaxin reduced PDL fiber organization. In-vitro mechanical testing and tooth mobility assessments indicated that the PDL of the mandibular incisors in the relaxin-treated rats had reduced yield load, strain, and stiffness. Moreover, the range of tooth mobility of the maxillary first molars increased to 130% to 170%, over vehicle-treated rats at day 1. Conclusions Human relaxin does not accelerate orthodontic tooth movement in rats; it can reduce the level of PDL organization, reduce PDL mechanical strength, and increase tooth mobility at early time points. PMID:17208099

Madan, Monica S.; Liu, Zee J.; Gu, Gao M.; King, Gregory J.

2010-01-01

244

Surgical-prosthetic management of facial soft tissue defects on anterior single implant-supported restorations: a clinical report.  

PubMed

The surgical correction of soft tissue defects on the facial aspects of dental implants is documented as an unpredictable procedure. Since the customization of the prosthetic emergence profile contributes significantly to the final esthetic outcome of the soft tissue, a combined surgical-prosthetic approach has been described in the literature. In the case presented in this article, a multidisciplinary approach was used to treat a patient's anterior sextant. It included the treatment of a previously placed implant, perfectly osseointegrated, with a 2 mm recession of the facial soft tissue. Two connective tissue grafting procedures were performed, in conjunction with the modification of the prosthetic profile of the provisional restoration and the definitive abutment. The final esthetic outcome satisfied the patient and resolved the main complaint, and is documented to have been stable for 5 years. PMID:25874274

Paniz, Gianluca; Mazzocco, Fabio

2015-01-01

245

Single phase formation of Co-implanted ZnO thin films by swift heavy ion irradiation: Optical studies  

SciTech Connect

Low temperature photoluminescence and optical absorption studies on 200 MeV Ag{sup +15} ion irradiated Co-implanted ZnO thin films were studied. The Co clusters present in as implanted samples were observed to be dissolved using 200 MeV Ag{sup +15} ion irradiation with a fluence of 1x10{sup 12} ions/cm{sup 2}. The photoluminescence spectrum of pure ZnO thin film was characterized by the I{sub 4} peak due to the neutral donor bound excitons and the broad green emission. The Co-doped ZnO films show three sharp levels and two shoulders corresponding to 3t{sub 2g} and 2e{sub g} levels of crystal field splitted Co d orbitals, respectively. The ultraviolet-visible absorption spectroscopy also shows the systematic variation of band gap after 200 MeV Ag{sup +15} ion irradiation.

Kumar, Ravi; Singh, Fouran; Angadi, Basavaraj; Choi, Ji-Won; Choi, Won-Kook; Jeong, Kwangho; Song, Jong-Han; Khan, M. Wasi; Srivastava, J. P.; Kumar, Ajay; Tandon, R. P. [Materials Science Division, Inter-University Accelerator Centre, P.O. Box 10502, Aruna Asaf Ali Marg, New Delhi 110067 (India); Thin Films Materials Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of); Institute of Physics and Applied Physics, Yonsei University, Shincheon-dong 134, Seoul 120-749 (Korea, Republic of); Advanced Analysis Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650 (Korea, Republic of); Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Department of Physics and Astrophysics, Delhi University, Delhi 110007 (India)

2006-12-01

246

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

247

Tooth fragment reattachment: An esthetic, biological restoration  

PubMed Central

Coronal fractures of the anterior teeth are a common form of dental trauma. If the original tooth fragment is retained following fracture, reattachment of the fractured fragment to the remaining tooth can provide better and long lasting esthetics, improved function, a positive psychological response, and is a faster and less complicated procedure. This paper reports on coronal tooth fracture case that was successfully treated using adhesive reattachment of fractured fragment and post placement.

Choudhary, Ajay; Garg, Rakesh; Bhalla, Anindya; Khatri, Rohit Kumar

2015-01-01

248

Simultaneous Bilateral Cochlear Implantation in Adults: A Multicenter Clinical Study  

E-print Network

Simultaneous Bilateral Cochlear Implantation in Adults: A Multicenter Clinical Study Ruth Litovsky- neous" bilateral cochlear implantation (both im- plants placed during a single surgical procedure sensori- neural hearing loss. Performance with the bilateral cochlear implants, using the same speech

Litovsky, Ruth

249

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

250

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

PubMed

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

Kokane, Vandana B; Patil, Swapnil N

2014-12-01

251

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

252

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2014 CFR

...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

253

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

254

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

255

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

256

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...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material,...

2011-04-01

257

21 CFR 872.5525 - Preformed tooth positioner.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Preformed tooth positioner. 872.5525 Section 872...Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that...

2011-04-01

258

21 CFR 872.5525 - Preformed tooth positioner.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Preformed tooth positioner. 872.5525 Section 872...Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that...

2010-04-01

259

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...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material,...

2010-04-01

260

Esthesioneuroblastoma presenting as tooth pain.  

PubMed

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

2014-09-01

261

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

262

Immunomodulation stimulates the innervation of engineered tooth organ.  

PubMed

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

263

Optical mode confinement and selection in single-crystal sapphire fibers by formation of nanometer scale cavities with hydrogen ion implantation  

NASA Astrophysics Data System (ADS)

The excellent material properties of single crystal sapphire fibers promise great advantages in applications related to harsh environment optical sensing, high laser power delivery, and high-resolution/sensitivity optical spectroscopy. However, the lack of viable cladding for confining light propagation in sapphire fibers with negligible transmission loss has restricted their practical applications. Despite great efforts in engineering either a low-refractive-index cladding layer or highly reflective mirror layer as sapphire fiber surface coatings, confining light propagation within sapphire fibers remains difficult in practice since such surface coatings fail to function due to increased thermal stress and fast erosion in environments with extremely high temperatures (>1000 °C) and chemically reactive species/gases. Here, we demonstrate a method for creating nanoscale cavities/voids in sapphire as effective fiber cladding structures that are thermally robust even at 1700 °C using hydrogen ion implantation. Material analysis of implanted sapphire crystals indicates that such nanoscale cavities play a key role in reducing the refractive index in sapphire crystals.

Spratt, William; Huang, Mengbing; Murray, Thomas; Xia, Hua

2013-11-01

264

Lead levels among various deciduous tooth types  

Microsoft Academic Search

The amount of lead in deciduous teeth has been used extensively as a marker for infant lead exposure and body burden. However, the pattern of lead abundances among the various tooth positions in a child's mouth appears to be non-uniform. Taken together these findings show an apparently inconsistent pattern among the tooth types. These comparisons are complicated by different research

Michael B. Rabinowitz; David Bellinger; Alan Leviton; Jung-Der Wang

1991-01-01

265

Addressing Tooth Decay in Head Start Children  

ERIC Educational Resources Information Center

Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

2012-01-01

266

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

267

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

268

Graphene-based wireless bacteria detection on tooth enamel.  

PubMed

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. PMID:22453836

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

2012-01-01

269

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

270

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

271

Biologically Based Restorative Management of Tooth Wear  

PubMed Central

The prevalence and severity of tooth wear is increasing in industrialised nations. Yet, there is no high-level evidence to support or refute any therapeutic intervention. In the absence of such evidence, many currently prevailing management strategies for tooth wear may be failing in their duty of care to first and foremost improve the oral health of patients with this disease. This paper promotes biologically sound approaches to the management of tooth wear on the basis of current best evidence of the aetiology and clinical features of this disease. The relative risks and benefits of the varying approaches to managing tooth wear are discussed with reference to long-term follow-up studies. Using reference to ethical standards such as “The Daughter Test”, this paper presents case reports of patients with moderate-to-severe levels of tooth wear managed in line with these biologically sound principles. PMID:22315608

Kelleher, Martin G. D.; Bomfim, Deborah I.; Austin, Rupert S.

2012-01-01

272

Controlling the Number of Tooth Rows  

NSDL National Science Digital Library

The organization and renewal capacity of teeth vary greatly among vertebrates. Mammals have only one row of teeth that are renewed at most once, whereas many nonmammalian species have multirowed dentitions and show remarkable capacity to replace their teeth throughout life. Although knowledge on the genetic basis of tooth morphogenesis has increased exponentially over the past 20 years, little is known about the molecular mechanisms controlling sequential initiation of multiple tooth rows or restricting tooth development to one row in mammals. Mouse genetics has revealed a pivotal role for the transcription factor Osr2 in this process. Loss of Osr2 caused expansion of the expression domain of Bmp4, a well-known activator of tooth development, leading to the induction of supernumerary teeth in a manner resembling the initiation of a second tooth row in nonmammalian species.

Marja L. Mikkola (University of Helsinki; Institute of Biotechnology REV)

2009-08-25

273

Tooth discoloration induced by endodontic sealers.  

PubMed

Endodontic therapy often results in discoloration of the tooth crown. The main causes are blood, necrotic pulp tissue, and endodontic materials. The staining potentials of various materials were examined in vitro by means of a visual method for tooth color determination. Extracted premolars were prepared, and the following sealers were introduced into the pulp cavities: Zinc oxide eugenol cement, Grossman's cement, AH26, Diaket, N2, Riebler's paste, Tubliseal, and Endomethasone. Before the sealers were applied, the original tooth colors were assessed on the external buccal tooth surfaces. Further color determinations were carried out at regular intervals up to 6 months after introduction of the sealers. Each material induced measurable tooth discoloration within 3 weeks. Riebler's paste caused the most severe discoloration while Diaket caused a mild stain. The other materials produced intermediate discolorations between those of Riebler and Diaket. PMID:3456145

van der Burgt, T P; Mullaney, T P; Plasschaert, A J

1986-01-01

274

Implant Overdentures: A New Standard of Care for Edentulous Patients— Current Concepts and Techniques  

Microsoft Academic Search

While most implant-based treatment has histori- cally focused on fixed prosthetic tooth replacement, the multitude of benefits to the edentulous population from implant overdentures is overwhelming in terms of improved function, emotional stability, physical health, and esthetics. Although there still remains a lack of consistency in terms of techniques, prosthetic design, and attachment systems, these aspects have been proven less

ROBERT C. VO GEL

275

Cochlear Implants  

MedlinePLUS

A cochlear implant is a small, complex electronic device that can help to provide a sense of sound. People who are ... of-hearing can get help from them. The implant consists of two parts. One part sits on ...

276

Carmustine Implant  

MedlinePLUS

Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of ... Carmustine implant comes as a small wafer that is placed in the brain by a doctor during surgery to ...

277

Cochlear Implants  

MedlinePLUS

... the process Understand (when able), along with their parents, their role in the successful use of cochlear implants Have (when able), along with their parents, realistic expectations for cochlear implant use Are willing ...

278

Cochlear implant  

MedlinePLUS

... antenna. This part of the implant receives the sound, converts the sound into an electrical signal, and sends it to ... implants allow deaf people to receive and process sounds and speech. However, it is important to understand ...

279

Goserelin Implant  

MedlinePLUS

Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer ... the treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications called ...

280

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

281

Oral implants.  

PubMed

Today, more and more evidence suggests that even small changes in hardware for oral implants may jeopardize its biocompatibility. Even the manner in which the hardware is sterilized can influence cellular adhesion. This review discusses the surface characteristics, configuration, and success rates of various oral implants, as well as the complications that can result following implantation. PMID:1777657

van Steenberghe, D

1991-04-01

282

Intraoperative comparison of sequential-pulse and single-pulse defibrillation in candidates for automatic implantable defibrillators.  

PubMed

Sixteen survivors of cardiac arrest underwent intraoperative comparison of the effectiveness of sequential-pulse and single-pulse defibrillation. Defibrillation was tested alternately with the single-pulse or sequential-pulse technique 10 seconds into an episode of ventricular fibrillation that was induced with alternating current. The sequential-pulse defibrillation technique using truncated exponential pulses was performed with a right ventricular endocardial catheter and a left ventricular epicardial patch electrode. The first pulse was delivered between the right ventricular apical and the superior vena caval electrode on the right ventricular endocardial catheter. The second pulse was delivered between the right ventricular apical electrode and the left ventricular patch electrode 0.2 ms after termination of the first pulse. Single-pulse defibrillation was performed with a standard intracardiac defibrillation system in which a single truncated exponential pulse was delivered across 2 epicardial patch electrodes positioned over the anterolateral right ventricle and the posterolateral left ventricle. During defibrillation threshold determination, voltage and current waveforms were recorded and integrated to determine delivered energy. Average defibrillation threshold leading-edge voltage for the sequential pulse technique was 496 +/- 140 V, compared with 365 +/- 157 V for the single-pulse technique (p less than 0.005). Defibrillation threshold leading-edge current for the sequential-pulse technique was 6.0 +/- 2.3 A, compared with 10.6 +/- 5.1 A for the single-pulse method (p less than 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3630945

Bardy, G H; Stewart, R B; Ivey, T D; Graham, E L; Adhar, G C; Greene, H L

1987-09-01

283

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

284

Computer simulation of tooth replacement with growth in lower tetrapods  

Microsoft Academic Search

It is now recognized that, in a majority of lower (non-mammalian) vertebrates, tooth replacement is continuous and the order of succession along the tooth row exhibits a temporal pattern. This temporal pattern is here described in terms of the Zahnreihen model of Edmund, which expresses the relationship between relative tooth ages and tooth positions along the jaw in terms of

John R. Bolt; Robert E. DeMar

1986-01-01

285

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

286

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

287

Bioengineered Teeth from Cultured Rat Tooth Bud Cells  

Microsoft Academic Search

The recent bioengineering of complex tooth structures from pig tooth bud tissues suggests the potential for the regeneration of mammalian dental tissues. We have improved tooth bioengineering methods by comparing the utility of cultured rat tooth bud cells obtained from three-to seven-day post-natal (dpn) rats for tooth-tissue-engineering applications. Cell-seeded biodegradable scaffolds were grown in the omenta of adult rat hosts

M. T. Duailibi; S. E. Duailibi; C. S. Young; J. D. Bartlett; J. P. Vacanti; P. C. Yelick

2004-01-01

288

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 ...

289

Sports Safety: Avoiding Tooth and Mouth Injuries  

MedlinePLUS

Sports Safety: Avoiding Tooth and Mouth Injuries A few years ago, a dental newsletter published what seemed ... the perfect dunk. In older children and adults, sports injuries are common. Dentists estimate that between 13% ...

290

The pattern of histogenesis and growth of tooth plates in larval stages of extant lungfish.  

PubMed Central

Comparison of new data obtained in this study on Protopterus aethiopicus with that published on Protopterus aethiopicus and Neoceratodus forsteri has confirmed the suggestion that the pattern of histogenesis of tooth plates in the early larval stages is very similar in the two genera. These similarities are more apparent both when a common terminology is adopted, based on a topogenic classification, and when the fundamental assumption is made that a single morphogenetic system operates for all odontodes. The model to explain the structure of all vertebrate dentitions with separate teeth in single or multiple tooth rows has been found to apply to dipnoan dentitions with fused teeth in a composite tooth plate. In this model, the epithelial invagination surrounding the margins of the tooth plate represents the dental lamina and, where this is in contact with mesenchymal cells, cell clusters (protogerms) arise. From these protogerms new odontodes (teeth) may develop if factors to inhibit differentiation are not present. Sites for initiation of odontodes become restricted to the labial margins of existing ridges on the tooth plate. Experimental studies on mammalian tooth germs are discussed and a model proposed for control of odontogenesis and histogenesis in dipnoan dentitions. Patterns of growth of hypermineralised petrodentine have been analysed and shown to depend initially on the arrangement of odontodes, and subsequently upon the ability of special cells in the pulp to generate new and wider layers of petrodentine. The initial pattern of petrodentine depends upon the position of odontodes in the forming ridges of the tooth plate. Subsequent patterns of petrodentine depend upon the extent of replacement growth beneath the tritural surface. Specialised cells, petroblasts, secrete the petrodentine within a shell of dentine. These cells differentiate from cells of the dental papilla after odontoblasts have begun to form dentine. They are regarded as a unique type of cell for dipnoans. Images Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:4077701

Smith, M M

1985-01-01

291

Tooth number, World War II, nuns, and the real fountain of youth.  

PubMed

A new appreciation for the direct relationship of mouth health to systemic health is forcing re-evaluation of previous concepts of oral health strategies. Although a person shows adaptation to loss of some permanent teeth, it appears a threshold of 10 functional pairs or 20 teeth have linkage to a number of disabling diseases of aging. The Shortened Dental Arch concept has limitations for sustainability and leaves little functional cushion. Nevertheless, when teeth are lost leaving fewer than 20, systemic disease and mortality risk increase significantly. Several theories try to explain the phenomenon. An unusually credible study, however, changes the metric to fewer teeth, nine or less, before a cognitive decline is noted. Due to a standardized high level of prosthodontic treatment in that study, some of the deleterious health effects of tooth loss appear to be mitigated. The importance of these findings has implications for tooth replacement strategies. Recognizing the huge biologic and psychological cost of tooth loss, a renewed emphasis to maintain natural teeth is indicated. When fewer than 20 teeth are viable, well-made prosthodontics, including maxillary complete denture or a mandibular partial or overdenture, both tooth- and implant-supported, could be remunerative therapies. PMID:24683924

Warpeha, Walter S

2014-01-01

292

Implantable Microimagers  

PubMed Central

Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

2008-01-01

293

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

294

Tooth design to avoid shearing stresses  

SciTech Connect

Teeth disposed on the bit face of a rotating bit are, angularly oriented on the sloping surface of the bit face such that a vertical loading force which is applied to each tooth vectorially sums with a wedging force exerted by the rock formation on each tooth to create a resultant force applied to the diamond cutting element included within the tooth. The angular orientation of the tooth is chosen such that the resultant force is applied to the diamond cutting element in a direction which minimizes shear stress on the element. For example, in the case where the diamond cutting element is an equilateral triangular prismatic element tangentially set on the bit face with one apical edge defined by two adjacent triangular sides outermost on the tooth, the orientation or inclination of the tooth with respect to the vertical loading force and wedge force is such that the resulting force lies near or on the disector of the dihedral angle formed by the apical edge. Similarly, the diamond cutting element is rearwardly raked in the longitudinal direction, generally parallel to the tangential motion during normal drilling as defined by the rotation of the bit, such that the vectorial sum of the vertical loading force in a reactive cutting force applies a resultant force on the diamond cutting element in a direction which minimizes shear stress, namely, in the example in a direction approximately perpendicular to one of the end faces of the triangular prismatic diamond cutting element.

Mengel, H. E.; Munzel, H.

1985-05-07

295

Present and future technologies of tooth whitening.  

PubMed

Dental stains can be broadly classified as intrinsic or extrinsic. Intrinsic stains are a result of defects in tooth development, fluorosis, or acquired through the use of tetracycline. Extrinsic stains are localized mainly in the pellicle and are generated by the reaction between sugars and amino acids or acquired from the retention of exogenous chromophores in the pellicle. Three clinical methods are currently used for measuring stain removal and tooth whitening in the development of new whitening technologies: Lobene Stain Index, Shade Guide Color Change, and Minolta ChromaMeter. Professional tooth whitening products rely on proven technologies--35% hydrogen peroxide for in-office power bleaching or 10% to 15% carbamide peroxide for at-home bleaching--to reduce intrinsic stain and change the inherent tooth color. Over-the-counter tooth whitening products use a combination of surfactants, abrasives, anticalculus agents, and low levels of hydrogen peroxide to reduce extrinsic stain and help maintain tooth whiteness after professional treatment. Future technologies for whitening teeth could involve the use of activating agents to enhance the performance of hydrogen peroxide and natural enzymes. PMID:11908346

Viscio, D; Gaffar, A; Fakhry-Smith, S; Xu, T

2000-01-01

296

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

297

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

298

Wnt5a plays a crucial role in determining tooth size during murine tooth development.  

PubMed

We have previously demonstrated that tooth size is determined by dental mesenchymal factors. Exogenous bone morphogenetic protein (BMP)4, Noggin, fibroblast growth factor (FGF)3 and FGF10 have no effect on tooth size, despite the expressions of Bmp2, Bmp4, Fgf3, Fgf10 and Lef1 in the dental mesenchyme. Among the wingless (Wnt) genes that are differentially expressed during tooth development, only Wnt5a is expressed in the dental mesenchyme. The aims of the present study were to clarify the expression pattern of Wnt5a in developing tooth germs and the role of Wnt5a in the regulation of tooth size by treatment with exogenous WNT5A with/without an apoptosis inhibitor on in vitro tooth germs combined with transplantation into kidney capsules. Wnt5a was intensely expressed in both the dental epithelium and mesenchyme during embryonic days 14-17, overlapping partly with the expressions of both Shh and Bmp4. Moreover, WNT5A retarded the development of tooth germs by markedly inducing cell death in the non-dental epithelium and mesenchyme but not widely in the dental region, where the epithelial-mesenchymal gene interactions among Wnt5a, Fgf10, Bmp4 and Shh might partly rescue the cells from death in the WNT5A-treated tooth germ. Together, these results indicate that WNT5A-induced cell death inhibited the overall development of the tooth germ, resulting in smaller teeth with blunter cusps after tooth-germ transplantation. Thus, it is suggested that Wnt5a is involved in regulating cell death in non-dental regions, while in the dental region it acts as a regulator of other genes that rescue tooth germs from cell death. PMID:21879290

Cai, Jinglei; Mutoh, Noriko; Shin, Jeong-Oh; Tani-Ishii, Nobuyuki; Ohshima, Hayato; Cho, Sung-Won; Jung, Han-Sung

2011-09-01

299

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

300

Ultrasonographic Detection of Tooth Flaws  

NASA Astrophysics Data System (ADS)

The goal of our work is to adapt pulse-echo ultrasound into a high resolution imaging modality for early detection of oral diseases and for monitoring treatment outcome. In this talk we discuss our preliminary results in the detection of: demineralization of the enamel and dentin, demineralization or caries under and around existing restorations, caries on occlusal and interproximal surfaces, cracks of enamel and dentin, calculus, and periapical lesions. In vitro immersion tank experiments are compared to results from a handpiece which uses a compliant delay line to couple the ultrasound to the tooth surface. Because the waveform echoes are complex, and in order to make clinical interpretation of ultrasonic waveform data in real time, it is necessary to automatically interpret the signals. We apply the dynamic wavelet fingerprint algorithms to identify and delineate echographic features that correspond to the flaws of interest in teeth. The resulting features show a clear distinction between flawed and unflawed waveforms collected with an ultrasonic handpiece on both phantom and human cadaver teeth.

Bertoncini, C. A.; Hinders, M. K.; Ghorayeb, S. R.

2010-02-01

301

Tooth Sensitivity in Fluorotic Teeth  

PubMed Central

Objectives: The aim of this study was to compare the demographic and clinical features of tooth sensitivity (TS) in subjects with and without fluorosis. Methods: A total of 2249 subjects (378 subjects with fluorosis and 1871 subjects without fluorosis) were examined for TS during a study period of one year and TS was determined in 122 subjects. The level of TS was evaluated on a visual analogue scale (VAS). The sensitivity evaluation was made by applying tactile and cold air stimuli. In teeth sensitive to any stimuli, the plaque index (PI), gingival index (GI), gingival recession (GR) and periodontal pocket depth (PPD) were recorded. Fluorosis was assessed using the Dean Index. Results: One hundred and twenty-two participants were found to have TS (5.42%). The frequency of TS in subjects with fluorosis was 9.26%, while the frequency of TS in subjects without fluorosis was 4.65%. There was a statistically significant difference between the groups in terms of TS frequency (P=0.0003). In contrast, there were no significant differences between the groups for periodontal parameters except PI. Conclusions: The results of the study showed that the subjects with fluorosis may have been suffering from TS more than the subjects with normal dentition. Further studies are necessary to determine the factors that contribute to sensitivity of teeth with fluorosis. PMID:21769268

Tonguc, Mine Ozturk; Ozat, Yener; Sert, Tugba; Sonmez, Yonca; Kirzioglu, F. Yesim

2011-01-01

302

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

303

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

304

Urogynecologic Surgical Mesh Implants  

MedlinePLUS

... Medical Devices Products and Medical Procedures Implants and Prosthetics Urogynecologic Surgical Mesh Implants Urogynecologic Surgical Mesh Implants ... More in Products and Medical Procedures Implants and Prosthetics Urogynecologic Surgical Mesh Implants Pelvic Organ Prolapse (POP) ...

305

Adhesion of Dental Materials to Tooth Structure  

NASA Astrophysics Data System (ADS)

The understanding and proper application of the principles of adhesion has brought forth a new paradigm in the realm of esthetic dentistry. Modern restorative tooth procedures can now conserve the remaining tooth-structure and also provide for the strengthening of the tooth. Adhesive restorative techniques call for the application and curing of the dental adhesive at the interface between the tooth tissue and the filling material. Hence the success of the restoration depends largely on the integrity of this interface. The mechanism of adhesion of the bonding materials to the dental hard tissue will be discussed in this paper. There are four main steps that occur during the application of the dental adhesive to the oral hard tissues: 1) The first step is the creation of a microstructure in the tooth enamel or dentin by means of an acidic material. This can be through the application of a separate etchant or can be accomplished in situ by the adhesive/primer. This agent has to be effective in removing or modifying the proteinaceous “smear” layer, which would otherwise act as a weak boundary layer on the surface to be bonded. 2) The primer/adhesive must then be able to wet and penetrate the microstructure created in the tooth. Since the surface energies of etched enamel and that of etched dentin are different finding one material to prime both types of dental tissues can be quite challenging. 3) The ionomer types of materials, particularly those that are carboxylate ion-containing, can chemically bond with the calcium ions of the hydroxyapatite mineral. 4) Polymerization in situ allows for micromechanical interlocking of the adhesive. The importance of having the right mechanical properties of the cured adhesive layer and its role in absorbing and dissipating stresses encountered by a restored tooth will also be discussed.

Mitra, Sumita B.

2000-03-01

306

Ion beam studies of hydrogen implanted Si wafers  

NASA Astrophysics Data System (ADS)

We have studied silicon-on-insulator (SOI) materials with two different ion beam analysis methods. The SOI samples were implanted with boron and hydrogen ions. After implantation the wafers were annealed, and some of them were bonded to thermally oxidized silicon wafers. The damage in silicon single crystal due to ion implantations has been studied by Rutherford Backscattering in the channeling mode (RBS/C). The content of the ion-implanted hydrogen has been studied by elastic recoil detection analysis (ERDA) method. The strength of the implanted region after thermal annealings were measured with the crack opening method. The boron implantation before hydrogen implantation resulted to shallower implantation depth and lower splitting temperature than in samples implanted with hydrogen only. The boron implantation after hydrogen implantation did not influence the splitting temperature and RBS spectra showed that B implantation drove the H deeper to the sample.

Nurmela, A.; Henttinen, K.; Suni, T.; Tolkki, A.; Suni, I.

2004-06-01

307

Quality of Life for Children with Cochlear Implants: Perceived Benefits and Problems and the Perception of Single Words and Emotional Sounds  

ERIC Educational Resources Information Center

Purpose: This study examined children's self-reported quality of life with a cochlear implant as related to children's actual perceptions of speech and the emotional information conveyed by sound. Effects of age at amplification with hearing aids and fitting of cochlear implants on perceived quality of life were also investigated. Method: A…

Schorr, Efrat A.; Roth, Froma P.; Fox, Nathan A.

2009-01-01

308

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

309

Interproximal wear facets and tooth associations in the Pa?alar hominoid sample  

Microsoft Academic Search

Interproximal wear facets were examined on hominoid teeth from the middle Miocene site at Pa?alar, Turkey. The aim was to find matches between adjacent premolar and molar teeth from single individuals that were collected in the field as isolated teeth and use them to reconstruct tooth rows. These were then used to investigate: (1) the wear gradient on the molar

Insaf Gençturk; Berna Alpagut; Peter Andrews

2008-01-01

310

Simple diagnostic method to assess the available bone for immediate implant placement in an extracted socket.  

PubMed

The success rate of immediate tooth replacement has been well documented in the literature. To achieve long-term success of dental implants, evaluation of the dimensions of the resorbing alveolar process must be accurate because an implant should be surrounded by at least 1 mm of bone. To minimize facial gingival recession, an intact labial bony plate along with an osseous-gingival relationship of 3 mm on the facial aspect of the failing tooth has been suggested. This article mentions a technique wherein the amount of available labial and palatal bone of an extracted socket can be assessed by using the extracted tooth that is to be replaced with an endosseous implant and a ridge mapping procedure without reflecting the flap. PMID:20690855

Chowdhary, Ramesh; Chandraker, Neeraj

2011-08-01

311

Dental Implant Surgery  

MedlinePLUS

... find out more. Wisdom Teeth Management Wisdom Teeth Management An impacted wisdom tooth can damage neighboring teeth ... find out more. Wisdom Teeth Management Wisdom Teeth Management An impacted wisdom tooth can damage neighboring teeth ...

312

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

313

Direct cord implantation in brachial plexus avulsions: revised technique using a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy  

Microsoft Academic Search

BACKGROUND: The superiority of a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy in direct cord implantation was investigated as to providing adequate exposure to both the cervical cord and the brachial plexus, as to causing less tissue damage and as to being more extensible than current surgical approaches. METHODS: The front and back of

Sherif M Amr; Ahmad M Essam; Ahmad M Kholeif; Ashraf N Moharram; Rashed ER El-Sadek

2009-01-01

314

Speech perception with the Vienna extra-cochlear single-channel implant: a comparison of two approaches to speech coding.  

PubMed

Although it is generally accepted that single-channel electrical stimulation can significantly improve a deafened patient's speech perceptual ability, there is still much controversy surrounding the choice of speech processing schemes. We have compared, in the same patients, two different approaches: (1) The speech pattern extraction technique of the EPI group, London (Fourcin et al., British Journal of Audiology, 1979,13,85-107) in which voice fundamental frequency is extracted and presented in an appropriate way, and (2) The analogue 'whole speech' approach of Hochmair and Hochmair-Desoyer (Annals of the New York Academy of Sciences, 1983, 405, 268-279) of Vienna, in which the microphone-sensed acoustic signal is frequency-equalized and amplitude-compressed before being presented to the electrode. With the 'whole-speech' coding scheme (which they used daily), all three patients showed an improvement in lipreading when they used the device. No patient was able to understand speech without lipreading. Reasonable ability to distinguish voicing contrasts and voice pitch contours was displayed. One patient was able to detect and make appropriate use of the presence of voiceless frication in certain situations. Little sensitivity to spectral features in natural speech was noted, although two patients could detect changes in the frequency of the first formant of synthesised vowels. Presentation of the fundamental frequency only generally led to improved perception of features associated with it (voicing and intonation). Only one patient consistently showed any advantage (and that not in all tests) of coding more than the fundamental alone. PMID:3754170

Rosen, S; Ball, V

1986-02-01

315

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

316

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

317

Part III: crystalline fluorapatite-coated hydroxyapatite; potential use as a bacteriostatic agent for both pre-implant cases and retreatment of infected implant sites: a report of 4 cases.  

PubMed

Four cases of peri-implant bone loss associated with undiagnosed necrotic pulps of adjacent teeth are reported. In two cases, bone was obliterated along sinus tracts (fistulas) that coursed between the implant and adjacent tooth. Endodontic treatment was completed on the adjacent teeth concurrent with periapical surgery to seal the tooth apex. The sinus tract (fistula) was excised, and the implant plus tooth surfaces were treated with a combination of concentrated citric acid and 4.3% sodium fluoride solutions. The third case involved peri-implant surgery with endodontic treatment on the adjacent tooth. A fourth case represented an infected socket augmentation which was surgically treated, augmented with microcrystalline fluorapatite in the range of a 300 µm to 400 µm cluster, and allowed to heal for 4 months followed by a trephine bone biopsy and subsequent analysis for bone growth around the fluoridated nonceramic microcrystalline hydroxyapatite (HA). An augmentation procedure employing fluoridated of resorbable HA was then completed. Histologic analysis showed healthy bone regeneration suggesting that therapeutic fluoride treatment and resultant fluorapatite were helpful in inhibiting reinfection following surgical treatment. All 4 infected implant sites were successfully managed and retained using the aforementioned treatment schemes, and there was no evidence of posttreatment infection in any of the 4 cases. It is proposed that fluoride treatment, through the use of 4.3% sodium fluoride and/or fluoridated hydroxyapatite (fluorapatite), shows promise as an adjunctive treatment component in inhibiting peri-implant infection and reinfection when managing ailing or failing implants. PMID:21028990

Nordquist, William D; Krutchkoff, David J

2011-01-01

318

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 ...

319

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2012 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth...

2012-04-01

320

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2014 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a...

2014-04-01

321

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth...

2013-04-01

322

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2010 CFR

...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

2010-04-01

323

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2011 CFR

...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

2011-04-01

324

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2014 CFR

...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

2014-04-01

325

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2012 CFR

...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

2012-04-01

326

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2013 CFR

...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

2013-04-01

327

Correspondence between tooth shape and dietary biomechanical properties in insectivorous  

E-print Network

Correspondence between tooth shape and dietary biomechanical properties in insectivorous the tooth shape of insectivores? We examined dietary `intractability', the extent to which structural to define them in biomechanical terms. The current study examines the guild of insectivores. Until recently

Evans, Alistair

328

Treatment imprudence leading to missed tooth fragment  

PubMed Central

Traumatic dental injuries (TDI) represent one of the most common oral health problems in children and adolescents. Dental trauma requires a special consideration when it accompanies soft tissue lacerations. Tooth fragments occasionally penetrate into soft tissues and may cause severe complications. This article describes the case of a 12-year-old girl with a fractured tooth fragment embedded in the lower lip for 4?months, which went unnoticed at her primary health centre. This report highlights the importance of proper radiographic diagnosis along with clinical examination after trauma in order to prevent any future complications. PMID:23606390

Barua, Pranamee; Chaudhary, Seema; Kaur, Harsimran; Mallikarjuna, Rachappa

2013-01-01

329

Preventive orthodontic management of tooth transposition.  

PubMed

The contemporary orthodontics should highlight the periodical control of growth and dental development in order to intercept possible disorders in facial growth and tooth eruption. This may allow avoidance or simplification of corrective orthodontic treatment, making it faster and less aggressive. Tooth transposition, a genetically determined eruptive disturbance, presents a relatively low prevalence in the world population and primarily affects maxillary canines and premolars. This paper presents an option for interceptive treatment of bilateral transposition of maxillary canine and premolar diagnosed early in a young individual. Longitudinal follow-up of RME performed in adequate timing to redirect the eruption pathway of permanent maxillary canines is presented. PMID:25745710

Cardoso, Mauricio de Almeida; Guedes, Fabio Pinto; Paranhos, Luiz Renato; Garib, Daniela Gamba; Capelozza Filho, Leopoldino

2014-01-01

330

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

331

Mechanisms Underlying Ectopic Persistent Tooth-Pulp Pain following Pulpal Inflammation  

PubMed Central

In order to clarify the peripheral mechanisms of ectopic persistent pain in a tooth pulp following pulpal inflammation of an adjacent tooth, masseter muscle activity, phosphorylated extracellular signal-regulated protein kinase (pERK) and TRPV1 immunohistochemistries and satellite cell activation using glial fibrillary acidic protein (GFAP) immunohistochemistry in the trigeminal ganglion (TG) were studied in the rats with molar tooth-pulp inflammation. And, Fluorogold (FG) and DiI were also used in a neuronal tracing study to analyze if some TG neurons innervate more than one tooth pulp. Complete Freund’s adjuvant (CFA) or saline was applied into the upper first molar tooth pulp (M1) in pentobarbital-anesthetized rats, and capsaicin was applied into the upper second molar tooth pulp (M2) on day 3 after the CFA or saline application. Mean EMG activity elicited in the masseter muscle by capsaicin application to M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. The mean number of pERK-immunoreactive (IR) TG cells was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. Application of the satellite cell inhibitor fluorocitrate (FC) into TG caused a significant depression of capsaicin-induced masseter muscle activity and a significant reduction of satellite cell activation. The number of TRPV1-IR TG cells innervating M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats, and that was decreased following FC injection into TG. Furthermore, 6% of TG neurons innervating M1 and/or M2 innervated both M1 and M2. These findings suggest that satellite cell activation following tooth pulp inflammation and innervation of multiple tooth pulps by single TG neurons may be involved in the enhancement of the activity of TG neurons innervating adjacent non-inflamed teeth that also show enhancement of TRPV1 expression in TG neurons, resulting in the ectopic persistent tooth-pulp pain following pulpal inflammation of adjacent teeth. PMID:23341909

Matsuura, Shingo; Shimizu, Kohei; Shinoda, Masamichi; Ohara, Kinuyo; Ogiso, Bunnai; Honda, Kuniya; Katagiri, Ayano; Sessle, Barry J.; Urata, Kentaro; Iwata, Koichi

2013-01-01

332

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

333

[A biomechanical study of dental implants using a method for 3-dimensional volumetric mathematical modelling].  

PubMed

Biomechanics of the dental implants introduced into alveoli immediately after tooth extraction has been investigated. The programme ANSYS has been used. Three-dimension volume mathematical models were calculated, with the help of which the tense-deformed state of the supportive biological tissues has been investigated in the area of direct implantation. On the grounds of the results obtained a conclusion has been made that there is an essential improvement of the load distribution under investigation of the inner bone modified biologically designed implants for direct implantation. PMID:10067415

Matveeva, A I; Gvetadze, R Sh; Loginov, V E; Gavriushin, S S; Karasev, A V

1998-01-01

334

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

335

Death in the Life of a Tooth  

Microsoft Academic Search

Programmed cell death (apoptosis) constitutes an important mechanism in embryonic development. Although there is substantial evidence for essential roles of apoptosis in organ shaping and controlling of cell number, the mechanisms of these processes are poorly understood. The regulation of cell proliferation to form tooth buds of the appropriate size and at the correct positions must involve a balance between

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

2004-01-01

336

Gastroesophageal Reflux Disease and Tooth Erosion  

PubMed Central

The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control. PMID:22194748

Ranjitkar, Sarbin; Kaidonis, John A.; Smales, Roger J.

2012-01-01

337

Tooth contact in patients with temporomandibular disorders.  

PubMed

Both experimental and retrospective studies suggest a link between parafunctions and pain in temporomandibular disorder (TMD) patients. To investigate the role of parafunctions in TMD, experience sampling methodology was used as a prospective test of the hypothesis that patients with TMD have higher levels of tooth contact and tension than non-TMD controls. Three groups of TMD patients and a group of normal controls carried pagers for one week, were contacted approximately every two hours by an automated calling system, and completed questionnaires assessing tooth contact, tension, and pain at each contact. Results showed that tooth contact was much more frequent among normal controls than is commonly presumed. Patients with myofascial pain with/without arthralgia reported more frequent contact, higher intensity contact, and more tension than patients with disk displacement or normal controls. Increased masticatory muscle activity responsible for tooth contact and tension may be an important mechanism in the etiology and maintenance of the myofascial pain and arthralgia of TMD. PMID:16128353

Glaros, Alan G; Williams, Karen; Lausten, Leonard; Friesen, Lynn R

2005-07-01

338

Tooth Retention, Tooth Loss and Use of Dental Care Among Long-Term Narcotics Abusers  

Microsoft Academic Search

This study examined tooth retention, tooth loss and use of dental care among aging male narcotics abusers being followed-up for more than 33 years. The cohort of 581 male narcotics addicts admitted to California Civil Addict Program in 1962-1964 was tracked until 1996-1997. As of 1997, 284 (48.9%) were confirmed to be dead. A total of 108 surviving participants completed

Jing Fan; Yih-Ing Hser; Diane Herbeck

2006-01-01

339

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

340

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

341

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

342

Detecting Inter-Cusp and Inter-Tooth Wear Patterns in Rhinocerotids  

PubMed Central

Extant rhinos are the largest extant herbivores exhibiting dietary specialisations for both browse and grass. However, the adaptive value of the wear-induced tooth morphology in rhinos has not been widely studied, and data on individual cusp and tooth positions have rarely been published. We evaluated upper cheek dentition of browsing Diceros bicornis and Rhinoceros sondaicus, mixed-feeding R. unicornis and grazing Ceratotherium simum using an extended mesowear method adapted for rhinos. We included single cusp scoring (EM(R)-S) to investigate inter-cusp and inter-tooth wear patterns. In accordance with previous reports, general mesowear patterns in D. bicornis and R. sondaicus were attrition-dominated and C. simum abrasion-dominated, reflecting their respective diets. Mesowear patterns for R. unicornis were more attrition-dominated than anticipated by the grass-dominated diet, which may indicate a low intake of environmental abrasives. EM(R)-S increased differentiation power compared to classical mesowear, with significant inter-cusp and inter-tooth differences detected. In D. bicornis, the anterior cusp was consistently more abrasion-dominated than the posterior. Wear differences in cusp position may relate to morphological adaptations to dietary regimes. Heterogeneous occlusal surfaces may facilitate the comminution of heterogeneous browse, whereas uniform, broad grinding surfaces may enhance the comminution of physically more homogeneous grass. A negative tooth wear gradient was found in D. bicornis, R. sondaicus and R. unicornis, with wear patterns becoming less abrasion-dominated from premolars to molars. No such gradients were evident in C. simum which displayed a uniform wear pattern. In browsers, premolars may be exposed to higher relative grit loads, which may result in the development of wear gradients. The second premolar may also have a role in food cropping. In grazers, high absolute amounts of ingested abrasives may override other signals, leading to a uniform wear pattern and dental function along the tooth row, which could relate to the observed evolution towards homodonty. PMID:24312507

Taylor, Lucy A.; Kaiser, Thomas M.; Schwitzer, Christoph; Müller, Dennis W. H.; Codron, Daryl; Clauss, Marcus; Schulz, Ellen

2013-01-01

343

A model of growth restraints to explain the development and evolution of tooth shapes in mammals.  

PubMed

The problem investigated here is control of the development of tooth shape. Cells at the growing soft tissue interface between the ectoderm and mesoderm in a tooth anlage are observed to buckle and fold into a template for the shape of the tooth crown. The final shape is created by enamel secreted onto the folds. The pattern in which the folds develop is generally explained as a response to the pattern in which genes are locally expressed at the interface. This congruence leaves the problem of control unanswered because it does not explain how either pattern is controlled. Obviously, cells are subject to Newton's laws of motion so that mechanical forces and constraints must ultimately cause the movements of cells during tooth morphogenesis. A computer model is used to test the hypothesis that directional resistances to growth of the epithelial part of the interface could account for the shape into which the interface folds. The model starts with a single epithelial cell whose growth is constrained by 4 constant directional resistances (anterior, posterior, medial and lateral). The constraints force the growing epithelium to buckle and fold. By entering into the model different values for these constraints the modeled epithelium is induced to buckle and fold into the different shapes associated with the evolution of a human upper molar from that of a reptilian ancestor. The patterns and sizes of cusps and the sequences in which they develop are all correctly reproduced. The model predicts the changes in the 4 directional constraints necessary to develop and evolve from one tooth shape into another. I conclude more generally expressed genes that control directional resistances to growth, not locally expressed genes, may provide the information for the shape into which a tooth develops. PMID:18838080

Osborn, Jeffrey W

2008-12-01

344

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

345

Dynamic analysis of straight and involute tooth forms  

NASA Technical Reports Server (NTRS)

The effect of load speed on straight and involute tooth forms is studied using several finite-element models. It is found that for rapidly rotating gears and sprockets, the load speed along the tooth surface can significantly affect the tooth vibration. Indeed, it is found that for sufficiently high load speeds and for sufficiently slender tooth forms, the tooth deflection can, at times, be directed opposite to the load direction. Comparisons are made of various dynamic models of gear and sprocket teeth. It is shown that for stubby tooth forms there is considerable difference between results obtained with finite element models and results obtained with Timoshenko beam models. Finally, it is shown that gear or sprocket vibrations can be induced by the shape of the tooth form itself. This effect becomes increasingly significant at higher speeds.

Lin, H. H.; Huston, R. L.; Coy, J. J.

1984-01-01

346

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

347

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

348

Immediate occlusal loading of freestanding implants using cortical satellite implants: preliminary report of a prospective study.  

PubMed

Freestanding implants with mandibular overdentures are used frequently after 3 months' healing time. Immediate full loading may be applied to this approach if sufficient primary stability is provided. The present study evaluates the success rate of two single-standing interforaminal implants stabilized with cortical satellite implants and loaded immediately with overdentures. Twenty patients (five male and 15 female; age, 45-87 years) received two single-standing titanium screw implants (Semados, Bego, Bremen, Germany). All implants were stabilized during healing time with cortical satellite implants (2.0-mm bone screws; Medartis, Basel, Switzerland) via individual connectors attached to the implant abutment subgingivally. Mandibular overdentures were incorporated immediately after surgery using ball attachments as retentive elements. The patients were under no restrictions concerning diet and loading. The satellite implants were removed after 3 months. All implants were osseointegrated after 10 months' mean observation time. The mean Periotest value was -4.9, and the mean marginal bone loss was 0.7 mm. No dropouts were observed, and 19 of 20 patients would recommend the treatment to a close friend. Preliminary follow-up data indicate that cortical stabilization of two anterior mandibular implants with satellite implants leads to osseointegration of the implants under immediate load conditions with an overdenture. This concept contributes to reduction of prosthetic treatment costs and permits immediate enhancement of masticatory function. PMID:15764945

Engelke, Wilfried; Decco, Oscar A; de las Mercedes Capobianco, María; Schwarzwäller, Wolfgang; Villavicencio, Milagros Mendoza

2005-03-01

349

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

350

Gingival recontouring by provisional implant restoration for optimal emergence profile: report of two cases  

PubMed Central

Purpose The emergence profile concept of an implant restoration is one of the most important factors for the esthetics and health of peri-implant soft tissue. This paper reports on two cases of gingival recontouring by the fabrication of a provisional implant restoration to produce an optimal emergence profile of a definitive implant restoration. Methods After the second surgery, a preliminary impression was taken to make a soft tissue working cast. A provisional crown was fabricated on the model. The soft tissue around the implant fixture on the model was trimmed with a laboratory scalpel to produce the scalloped gingival form. Light curing composite resin was added to fill the space between the provisional crown base and trimmed gingiva. After 4 to 6 weeks, the final impression was taken to make a definitive implant restoration, where the soft tissue and tooth form were in harmony with the adjacent tooth. Results At the first insertion of the provisional restoration, gum bleaching revealed gingival pressure. Four to six weeks after placing the provisional restoration, the gum reformed with harmony between the peri-implant gingiva and adjacent dentition. Conclusions Gingival recontouring with a provisional implant restoration is a non-surgical and non-procedure-sensitive method. The implant restoration with the optimal emergence profile is expected to provide superior esthetic and functional results. PMID:22324008

Son, Mee-Kyoung

2011-01-01

351

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

352

Case report using the "h" abutment: achieving esthetics, strength, and predictability for the anterior implant.  

PubMed

Replacing an anterior tooth using a dental implant has long been a challenge for most clinicians. Implant abutment selection is a crucial aspect of maximizing esthetics, strength, and customization. The author has experienced significant success in this regard over a period of more than 7 years using a lithium-disilicate "H" ("Hybrid") abutment. In this case presentation, a procedure is described for providing these highly esthetic abutment-supported restorations, which may offer significant advantages over traditional options. PMID:25822745

Hornbrook, David

2015-03-01

353

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

354

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

PubMed

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

2014-12-01

355

Cochlear Implants  

MedlinePLUS

... during an optimal period to develop speech and language skills. A growing body of research, much of it funded by the NIDCD, has shown that when these children receive a cochlear implant ... a young age develop language skills at a rate comparable to children with ...

356

Ridge Preservation for Implant Therapy: a Review of the Literature  

PubMed Central

Healing of the extraction socket after tooth removal involves retention of the blood clot followed by a sequence of events that lead to changes in the alveolar process in a three dimensional fashion. This normal healing event results in a minimal loss of vertical height (around 1 mm), but a substantial loss of width in the buccal-lingual plane (4-6 mm). During the first three months following extraction that loss has been shown to be significant and may result in both a hard tissue and soft tissue deformity affecting the ability to restore the site with acceptable esthetics. Procedures that reduce the resorptive process have been shown to be predictable and potentially capable of eliminating secondary surgery for site preparation when implant therapy is planned. The key element is prior planning by the dental therapist to act at the time of extraction to prevent the collapse of the ridge due to the loss of the alveolus. Several techniques have been employed as ridge preservation procedures involving the use of bone grafts, barrier membranes and biologics to provide a better restorative outcome. This review will explore the evidence behind each technique and their efficacy in accomplishing site preparation. The literature does not identify a single technique as superior to others; however, all accepted therapeutic procedures for ridge preservation have been shown to be more effective than blood clot alone in randomized controlled studies. PMID:24893595

Tomlin, Elizabeth M; Nelson, Shelby J; Rossmann, Jeffrey A

2014-01-01

357

Tooth configuration for an earth boring bit  

SciTech Connect

A polycrystalline diamond cutting element in a earth boring bit is affixed to the bit face by an improved tooth. The tooth includes a prepad extending from the face of the mining bit contiguous to and substantially congruous with that portion of a polycrystalline diamond element also extending from the bit face. A trailing support is provided behind the polycrystalline diamond element and is similarly contiguous and substantially congruous therewith so that a generally singular geometrically shaped body is formed by the prepad, the polycrystalline diamond element and the trailing support. The prepad and trailing support are integrally formed from the matrix material of the rotary bit and are generally arcuate about a radius centered on the bit face. The polycrystalline diamond element is thus securely retained on the bit face while exposing a maximum extent of the polycrystalline diamond element sandwiched between the prepad and trailing support.

Grappendorf, R. H.; Brown, J. L.

1985-02-19

358

Iatrogenic traumatic brain injury during tooth extraction.  

PubMed

An 8 yr old spayed female Yorkshire terrier was referred for evaluation of progressive neurological signs after a routine dental prophylaxis with tooth extractions. The patient was circling to the left and blind in the right eye with right hemiparesis. Neurolocalization was to the left forebrain. MRI revealed a linear tract extending from the caudal oropharynx, through the left retrobulbar space and frontal lobe, into the left parietal lobe. A small skull fracture was identified in the frontal bone through which the linear tract passed. Those findings were consistent with iatrogenic trauma from slippage of a dental elevator during extraction of tooth 210. The dog was treated empirically with clindamycin. The patient regained most of its normal neurological function within the first 4 mo after the initial injury. Although still not normal, the dog has a good quality of life. Traumatic brain injury is a rarely reported complication of extraction. Care must be taken while performing dental cleaning and tooth extraction, especially of the maxillary premolar and molar teeth to avoid iatrogenic damage to surrounding structures. PMID:25695556

Troxel, Mark

2015-01-01

359

Implant Chips  

NSDL National Science Digital Library

A group of eight people, including all members of one Florida family, had an implant chip, roughly the size of a grain of rice, injected under their skin on Friday, May 10. Manufactured by Applied Digital Solutions (ADS), the chips store a special identification number that enables the retrieval of personal and medical information. In the event of a medical emergency, a special handheld scanner activates the dormant digital implant, which provides identification data with which medical personnel can query ADS's database, the location of the patient's medical records. Alzheimer's patients seem to be the most promising market for this technology, even though other people, like the Florida family, hope to benefit from it as well. Another product that ADS offers is called Digital Angel, a wearable global positioning system (GPS) device that, among other things, can track in real time the wearer's physical movements. In the future, ADS is planning to release a product that will utilize both of these technologies: an implanted GPS-enabled chip. Unlike VeriChip, though, the GPS-enabled implant would require Food and Drug Administration (FDA) approval, meaning the US market won't see its introduction until after FDA testing. Many organizations, ranging from privacy advocates to religious groups, have already denounced VeriChip and its eventually successors, associated them with "Big Brother" and the biblical "Mark of the Beast."To read about the eight people that received their implants, look at the first and second sites, articles from the Los Angeles Times and Miami Herald respectively. For a non-US perspective, view the news story posted by the British Broadcasting Company (BBC). The fourth site, an extensive analysis of the subject from ABC News, should give readers a broader understanding of implanted chips and their potential uses. Two sites from ADS are next -- VeriChip's product pages and the press release that details a FDA's decision regarding VeriChip in April, 2002. Finally, the last two sites give more information on Digital Angel and a sample of GPS technology already in use.

Schroeder, Ted.

2002-01-01

360

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. PMID:25685843

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

2015-01-01

361

Efficacy of nonthermal atmospheric pressure plasma for tooth bleaching.  

PubMed

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 energy source, which has no deleterious effects on the tooth surface. PMID:25685843

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

2015-01-01

362

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

363

Local Synthesis and Tooth Contact Analysis of Face-Milled, Uniform Tooth Height Spiral Bevel Gears  

NASA Technical Reports Server (NTRS)

Face-milled spiral bevel gears with uniform tooth height are considered. An approach is proposed for the design of low-noise and localized bearing contact of such gears. The approach is based on the mismatch of contacting surfaces and permits two types of bearing contact either directed longitudinally or across the surface to be obtained. Conditions to avoid undercutting were determined. A Tooth Contact Analysis (TCA) was developed. This analysis was used to determine the influence of misalignment on meshing and contact of the spiral bevel gears. A numerical example that illustrates the theory developed is provided.

Litvin, F. L.; Wang, A. G.

1996-01-01

364

[Large dentigerous cyst caused by retained tooth 25].  

PubMed

Follicular cysts are benign, non-inflammatory odontogenic cysts, usually painless and discovered during routine radiographic examination. The article describes a case of a large follicular cyst with retained tooth 25. Pantomographic x ray showed the presence of a large follicular cyst located on the side of the impacted 25 tooth. The cyst has been enucleated and the tooth extracted surgically with subsequent closure of oro-antral communication. After 3 months orthodontic treatment was initiated. PMID:25182400

Janas, Anna; Stelmach, Rafa?; Osica, Piotr

2014-01-01

365

Bone's responses to different designs of implant-supported fixed partial dentures.  

PubMed

This paper explores the biomechanics and associated bone remodeling responses of two different abutment configurations, namely implant-implant-supported versus tooth-implant-supported fixed partial dentures. Two 3D finite element analysis models are created based upon computerized tomography data. The strain energy density induced by occlusal loading is used as a mechanical stimulus for driving the bone remodeling. To measure osseointegration and stability during healing, a resonance frequency analysis is conducted. At the second premolar peri-implant region, overloading resorption around the neck of implant is identified in both the models over the first 12 months. Stress-shielding around the edentulous region is also observed in both the models with a greater resorption rate found in the implant-implant case. The remodeling and resonance frequency analyses reveal that the tooth-implant scheme offers a higher degree of osseointegration. The remodeling procedure is expected to provide prosthodontists with a modeling tool to assess possible long-term clinical outcomes. PMID:25209424

Rungsiyakull, Chaiy; Chen, Junning; Rungsiyakull, Pimduen; Li, Wei; Swain, Michael; Li, Qing

2015-04-01

366

LANGUAGE DEVELOPMENT IN PROFOUNDLY DEAF CHILDREN WITH COCHLEAR IMPLANTS  

Microsoft Academic Search

Although cochlear implants improve the ability of pro- foundly deaf children to understand speech, critics claim that the published literature does not document even a single case of a child who has developed a linguistic system based on input from an implant. Thus, it is of clinical and scientific importance to determine whether cochlear implants facilitate the development of English

Mario A. Svirsky; Amy M. Robbins; Karen Iler Kirk; David B. Pisoni; Richard T. Miyamoto

2000-01-01

367

An implantable myoelectric sensor based prosthesis control system.  

PubMed

We present progress on the design and testing of an upper-extremity prosthesis control system based on implantable myoelectric sensors. The implant consists of a single silicon chip packaged with transmit and receive coils. Forward control telemetry to, and reverse EMG data telemetry from multiple implants has been demonstrated. PMID:17946995

DeMichele, Glenn A; Troyk, Philip R; Kerns, Douglas A; Weir, Richard

2006-01-01

368

An overview of tooth discoloration: extrinsic, intrinsic and internalized stains.  

PubMed

The causes of tooth discoloration are varied and complex but are usually classified as being either intrinsic, extrinsic or internalized in nature. Dietary chromogens and other external elements deposit on the tooth surface or within the pellicle layer either directly or indirectly to form extrinsic discoloration. Stains within the dentine or intrinsic discoloration often results from systemic or pulpal origin, while internalized stains are the result of extrinsic stains entering the dentine via tooth defects such as cracks on the tooth surface. PMID:16262034

Sulieman, M

2005-10-01

369

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

370

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

371

Development and Evolution of Dentition Pattern and Tooth Order in the Skates And Rays (Batoidea; Chondrichthyes)  

PubMed Central

Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the general plesiomorphic vertebrate dental condition. PMID:25874547

Underwood, Charlie J.; Johanson, Zerina; Welten, Monique; Metscher, Brian; Rasch, Liam J.; Fraser, Gareth J.; Smith, Moya Meredith

2015-01-01

372

Prosthodontic rehabilitation of malpositioned implants after ameloblastoma followed by mandibulectomy and costal bone graft: a clinical report.  

PubMed

This clinical report describes the rehabilitation with costal bone graft reconstruction and 3 implants of a patient with a partial mandibular defect as a result of a partial mandibulectomy due to ameloblastoma of the left mandible. Due to the altered shape of the graft bone, the implants were malpositioned in the buccolingual plane. The prosthodontic rehabilitation was successfully completed by using an implant-supported milled bar combined with telescopic crown-retained dentures. This tooth implant-supported prosthesis successfully restored function and esthetics. Aspects that deal with the repair of the buccal soft tissues are discussed. PMID:23287980

Wang, Wei; Mao, Cai-Yun; Gu, Xin-Hua

2013-02-01

373

BENDABLE VS. ANGULATED DENTAL IMPLANTS: CONSIDERATION OF ELASTIC AND PLASTIC MATERIAL PROPERTIES BASED ON EXPERIMENTAL IMPLANT MATERIAL DATA AND FEA  

Microsoft Academic Search

Aim: Bendable and angulated single-piece implants are used alternatively to screwable abutments in two-piece dental implant designs. Though used frequently, data on the stress distribution within such implants are not available and the question whether the bending contributes to fracture resistance has not been addressed. Methods: We used the method of fi nite element to identify von Mises stresses and

T. Goldmann; S. Ihde; J. Kuzelka; L. Himmlova

374

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

375

Simulated Single Tooth Bending of High Temperature Alloys  

NASA Technical Reports Server (NTRS)

Future unmanned space missions will require mechanisms to operate at extreme conditions in order to be successful. In some of these mechanisms, very high gear reductions will be needed to permit very small motors to drive other components at low rotational speed with high output torque. Therefore gearing components are required that can meet the mission requirements. In mechanisms such as this, bending fatigue strength capacity of the gears is very important. The bending fatigue capacity of a high temperature, nickel-based alloy, typically used for turbine disks in gas turbine engines and two tool steel materials with high vanadium content, were compared to that of a typical aerospace alloy-AISI 9310. Test specimens were fabricated by electro-discharge machining without post machining processing. Tests were run at 24 and at 490 C. As test temperature increased from 24 to 490 C the bending fatigue strength was reduced by a factor of five.

Handschuh, Robert, F.; Burke, Christopher

2012-01-01

376

Auditory Midbrain Implant: A Review  

PubMed Central

The auditory midbrain implant (AMI) is a new hearing prosthesis designed for stimulation of the inferior colliculus in deaf patients who cannot sufficiently benefit from cochlear implants. The authors have begun clinical trials in which five patients have been implanted with a single shank AMI array (20 electrodes). The goal of this review is to summarize the development and research that has led to the translation of the AMI from a concept into the first patients. This study presents the rationale and design concept for the AMI as well a summary of the animal safety and feasibility studies that were required for clinical approval. The authors also present the initial surgical, psychophysical, and speech results from the first three implanted patients. Overall, the results have been encouraging in terms of the safety and functionality of the implant. All patients obtain improvements in hearing capabilities on a daily basis. However, performance varies dramatically across patients depending on the implant location within the midbrain with the best performer still not able to achieve open set speech perception without lip-reading cues. Stimulation of the auditory midbrain provides a wide range of level, spectral, and temporal cues, all of which are important for speech understanding, but they do not appear to sufficiently fuse together to enable open set speech perception with the currently used stimulation strategies. Finally, several issues and hypotheses for why current patients obtain limited speech perception along with several feasible solutions for improving AMI implementation are presented. PMID:19762428

Lim, Hubert H.; Lenarz, Minoo; Lenarz, Thomas

2009-01-01

377

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

378

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

Code of Federal Regulations, 2013 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...

2013-04-01

379

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

Code of Federal Regulations, 2012 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...

2012-04-01

380

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

Code of Federal Regulations, 2011 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...

2011-04-01

381

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

382

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

383

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

384

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

385

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

386

Cracked tooth syndrome. Part 2: restorative options for the management of cracked tooth syndrome  

Microsoft Academic Search

The second of this two part series on 'cracked tooth syndrome' will focus on the available methods for the immediate, intermediate and definitive management of patients affected by this condition. Included in this article is a comprehensive account of the relative merits\\/drawbacks of various restorative materials and their respective techniques of application for the treatment of symptomatic, incompletely fractured posterior

S. Banerji; S. B. Mehta; B. J. Millar

2010-01-01

387

Gene Expression Profiling during Murine Tooth Development  

PubMed Central

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

388

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

2015-03-01

389

Role of stem cells in tooth bioengineering  

PubMed Central

The creation of teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin, and enamel. This review focuses on the different sources of stem cells that have been used for making teeth in vitro. The search was performed from 1970 to 2012 and was limited to English language papers. The keywords searched on medline were ‘stem cells and dentistry,’ ‘stem cells and odontoblast,’ ‘stem cells and dentin,’ and ‘stem cells and ameloblasts.’

Singh, Kamleshwar; Mishra, Niraj; Kumar, Lakshya; Agarwal, Kaushal Kishore; Agarwal, Bhaskar

2012-01-01

390

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

391

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

392

Common developmental pathways link tooth shape to regeneration  

PubMed Central

In many non-mammalian vertebrates, adult dentitions result from cyclical rounds of tooth regeneration wherein simple unicuspid teeth are replaced by more complex forms. Therefore and by contrast to mammalian models, the numerical majority of vertebrate teeth develop shape during the process of replacement. Here, we exploit the dental diversity of Lake Malawi cichlid fishes to ask how vertebrates generally replace their dentition and in turn how this process acts to influence resulting tooth morphologies. First, we used immunohistochemistry to chart organogenesis of continually replacing cichlid teeth and discovered an epithelial down-growth that initiates the replacement cycle via a labial proliferation bias. Next, we identified sets of co-expressed genes from common pathways active during de novo, lifelong tooth replacement and tooth morphogenesis. Of note, we found two distinct epithelial cell populations, expressing markers of dental competence and cell potency, which may be responsible for tooth regeneration. Related gene sets were simultaneously active in putative signaling centers associated with the differentiation of replacement teeth with complex shapes. Finally, we manipulated targeted pathways (BMP, FGF, Hh, Notch, Wnt/?-catenin) in vivo with small molecules and demonstrated dose-dependent effects on both tooth replacement and tooth shape. Our data suggest that the processes of tooth regeneration and tooth shape morphogenesis are integrated via a common set of molecular signals. This linkage has subsequently been lost or decoupled in mammalian dentitions where complex tooth shapes develop in first generation dentitions that lack the capacity for lifelong replacement. Our dissection of the molecular mechanics of vertebrate tooth replacement coupled to complex shape pinpoints aspects of odontogenesis that might be re-evolved in the lab to solve problems in regenerative dentistry. PMID:23422830

Fraser, Gareth J.; Bloomquist, Ryan F.; Streelman, J. Todd

2013-01-01

393

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

394

Ultrastructure and growth of the sea urchin tooth  

Microsoft Academic Search

Individual sea urchin teeth consist of many elements, each secreted by a syncytium formed for the purpose. The numerous syncytia of each tooth take up secondary connection with one another in the vicinity of needles and prisms. The elements of the primary tooth skeleton are surrounded by cytoplasm and are therefore intracellular. Following the origin of a syncytium in the

Ernst Kniprath

1974-01-01

395

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

396

Blood lead—Tooth lead relationship among Boston children  

Microsoft Academic Search

The amount of lead in deciduous teeth has been used extensively as a marker for infant lead exposure and body burden. Elevated tooth lead levels have been seen in children who had lead poisoning. Also, on a population wide basis tooth lead levels appear to vary according to housing status and presumably lead exposure. This exposure index has been applied

Michael B. Rabinowitz; Alan Leviton; David C. Bellinger

1989-01-01

397

Spatial and temporal events in tooth development of Astyanax mexicanus.  

PubMed

The Mexican tetra (Astyanax mexicanus), a freshwater teleost fish, is an excellent vertebrate model organism to study tooth development, specifically the spatiotemporal events related to the development of the oral and pharyngeal dentitions. In contrast to the coordinated early tooth development in the premaxilla and mandible, the maxillary teeth develop much later in life at 60?dpf. By analysing a growth series of bone and cartilage stained tetra and histological sectioning of the tooth bearing bones, we track the developmental events of tooth development over ontogeny of this animal. Whole mount in situ hybridisation with bone morphogenetic proteins and their inhibitor Noggin was conducted to track the late tooth development events. Our data show that the first generation teeth are small and unicuspid irrespective of their location. Oral jaw teeth become multicuspid and large over ontogeny while the pharyngeal dentition remains unicuspid and disorganised. Tooth eruption occurs late in the maxillary bone. The distinct expression pattern of the BMP antagonist, Noggin, suggests that Noggin plays an inhibitory role by preventing early tooth development in the maxillary bone. These data further support and highlight the use of the Mexican tetra in understanding the spatio-temporal differences in tooth development in vertebrate jaws. PMID:25290235

Atukorala, Atukorallaya Devi Sewvandini; Franz-Odendaal, Tamara Anne

2014-11-01

398

Hierarchical structure and biomineralization in cricket tooth  

E-print Network

Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a d...

Xing, Xueqing; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhongjun; Wu, Zhonghua

2012-01-01

399

Hierarchical structure and biomineralization in cricket tooth  

E-print Network

Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a detailed discussion was given in this paper.

Xueqing Xing; Yu Gong; Quan Cai; Guang Mo; Rong Du; Zhongjun Chen; Zhonghua Wu

2012-03-20

400

Assessment of demographic and clinical data related to dental implants in a group of Turkish patients treated at a university clinic  

PubMed Central

PURPOSE This retrospective study analyzed the distribution of the dental implants with regards to age and gender of the patients and type of indication for the implant therapy, as well as the location, dimension and type of the implants. MATERIALS AND METHODS The data of demographics (age and gender), type of indication for implant therapy, anatomical location, dimensions (length and diameter) and type (bone and tissue level) of 1616 implants were recorded from patient charts between January 2000 and January 2010. Descriptive statistics were analyzed using a chi-squared test for demographic parameters, type of indication, tooth position, anatomical location, implant dimensions and type (?=.05). RESULTS The patient pool comprised of 350 women and 266 men, with a mean age of 52.12 ± 13.79 years. The difference in n% of the implants of the age groups was statistically significant between the types of indications. The difference in the position of the implants was statistically significant between the n% of the implants of all age groups. Gender did not significantly vary, except that the diameter of the implants was significantly higher for the standard diameter implants in males. The difference between the implant positions was statistically significant when considered according to indication. The relationship between implant length and anatomical location was statistically significant. CONCLUSION The indication for dental implant use is age dependent and the type and size of the implant seems to be strongly related to the location of the implant. PMID:24049578

Bural, Canan; Bilhan, Hakan; Çilingir, Altu?

2013-01-01

401

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

402

Asyndromic hypodontia associated with tooth morphology alteration: A rare case report  

PubMed Central

Clinicians frequently encounter hypodontia in their practice. It can be associated with any syndrome or more commonly it is asyndromic. This asyndromic form is commonly familial and can be followed in heredity of the patient. The patient referred in this report presented with a rare anomaly of hypodontia with altered morphology where the patient had all the teeth single rooted and single canalled. Studies have indicated several genes that affect the tooth morphology and number. A genetic correlation of hypodontia with altered permanent teeth morphology may be explored further in studies. PMID:23833465

Agarwal, Abhinay; Gundappa, Mohan; Miglani, Sanjay; Nagar, Rohit

2013-01-01

403

Masticatory function following implants replacing a second molar  

PubMed Central

Purpose The aim of this study was to obtain objective and standardized information on masticatory function and patient satisfaction following second molar single implant therapy. Methods Twenty adult patients, who had restored second molar single implants more than 1 month before the study, were enrolled in this study. All patients received a chewing test using peanuts before and after insertion of the implant prosthesis, with a questionnaire and visual analogue scale (VAS) to evaluate the effect of second molar single implant therapy. Results This study obtained standardized information on the masticatory function objectively (e.g., P, R, X50) before (Pre-insertion) and after insertion (Post-insertion) of the implant prosthesis. Masticatory performance (P) after insertion of the implant prosthesis significantly increased from 67.8±9.9 to 84.3±8.5% (P<0.0001). With the implant prosthesis, the P value increased by 24%. The masticatory efficiency index (R) of Post-insertion is higher than that of Pre-insertion (P<0.0001). With the implant prosthesis, the R value increased by 29%. The median particle size (X50) of Post-insertion is lower than that of Pre-insertion (P<0.0001). More than 90% of the patients were satisfied with the second molar single implant therapy from a functional point of view. Conclusions These findings indicate that a second molar single implant can increase masticatory function. PMID:21556258

Kim, Moon-Sun; Lee, Jae-Kwan; Chang, Beom-Seok

2011-01-01

404

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

405

Chronology of alveolar healing following immediate implantation of Ricinus communis polyurethane resin: histometric analysis in rats.  

PubMed

The purpose of the present study was to determine whether granules of Ricinus communis polyurethane resin implanted immediately after tooth extraction interfere with the time course of alveolar wound healing in rats. Progressive bone neoformation in parallel to a decrease in the volume fraction of connective tissue was quantified by a histometric method 1, 2, 3, and 6 weeks after tooth extraction. In spite of the biocompatible nature, the presence of polyurethane resin granules in the cervical third led to a small (9-22%) but significant delay in bone formation in the middle and apical alveolar thirds from the second week on, as compared to controls. PMID:9407291

Carvalho, T L; Teófilo, J M; Araújo, C A; Brentegani, L G

1997-12-15

406

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

407

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

408

[A new implant system for orbital prosthetic rehabilitation: "epiplating mono"].  

PubMed

A New Implant System for Orbital Prosthetic Rehabilitation: "Epiplating Mono" Prosthetic or episthetic rehabilitation of ear, eye and nose are currently most common performed using magnetic fixation. While at the beginning single implants have been used, now-a-days a more extended approach with plate fixation are recommended to enhance the stability of the anchored magnets. A newly designed implant system epiplating mono is presented that combines the structure of a single implant with additional fixation elements. In a pilot study this new implant system was used in 4 patients for prosthetic orbital rehabilitation. Further experiences with this new implant system are required necessitating long-term experiences of implant stability to define the value of the presented epiplating mono system for prosthetic rehabilitation. PMID:24863910

Schneider, M; Federspil, P A; Neumann, A; Schick, B

2014-06-01

409

EVALUATION OF TISSUE RESPONSE TO PERIODONTAL DRESSINGS: HISTOLOGICAL STUDY IN TOOTH SOCKETS OF RATS  

PubMed Central

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p<0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p<0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p<0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pac™ dressing induced a more intensive inflammatory reaction at 28 days. PMID:19089222

Saito, Célia Tomiko Matida Hamata; Bernabé, Pedro Felício Estrada; Okamoto, Tetuo; Murata, Sueli Satomi; Hamata, Marcelo Matida; Sundefeld, Maria Lúcia Marçal Mazza

2008-01-01

410

Directional escape behavior in allis shad (Alosa alosa) exposed to ultrasonic clicks mimicking an approaching toothed whale.  

PubMed

Toothed whales emit high-powered ultrasonic clicks to echolocate a wide range of prey. It may be hypothesized that some of their prey species have evolved capabilities to detect and respond to such ultrasonic pulses in a way that reduces predation, akin to the situation for many nocturnal insects and echolocating bats. Using high-speed film recordings and controlled exposures, we obtained behavioural evidence that simulated toothed whale biosonar clicks elicit highly directional anti-predator responses in an ultrasound-sensitive allis shad (Alosa alosa). Ten shad were exposed to 192 dB re. 1 ?Pa (pp) clicks centred at 40 kHz at repetition rates of 1, 20, 50 and 250 clicks s(-1) with summed energy flux density levels of 148, 161, 165 and 172 dB re. 1 ?Pa(2) s. The exposures mimicked the acoustic exposure from a delphinid toothed whale in different phases of prey search and capture. The response times of allis shad were faster for higher repetition rates of clicks with the same sound pressure level. None of the fish responded to a single click, but had median response times of 182, 93 and 57 ms when exposed to click rates of 20, 50 and 250 clicks s(-1), respectively. This suggests that the ultrasound detector of allis shad is an energy detector and that shad respond faster when exposed to a nearby fast-clicking toothed whale than to a slow-clicking toothed whale far away. The findings are thus consistent with the hypothesis that shad ultrasound detection is used for reducing predation from echolocating toothed whales. PMID:21147965

Wilson, Maria; Schack, Henriette B; Madsen, Peter Teglberg; Surlykke, Annemarie; Wahlberg, Magnus

2011-01-01

411

Submandibular swelling: tooth or salivary stone?  

PubMed

Submandibular swelling is a common clinical disorder of the maxillo-facial region that may be one of the manifestation of several pathologic disorders including sialolithiasis. A 38-year-old woman experienced a recurrent painful swelling in the right submandibular region for seven years. The symptoms, not always meal-related, gradually became chronic and associated with dysphagia, odynophagia and fever. Ultrasonography of the salivary glands revealed a retained glandular structure and no ductal obstruction or dilatation, and orthopantomography showed the presence of a structure compatible with tooth, but these findings did not correlate with clinical scenario. Only CT dental scan identified the radiological image as a salivary stone. Sialolithiasis should always be considered in the diagnostic iter of painful submandibular swelling. A careful evaluation of recurrence and characteristics of signs and symptoms associated to the swelling can help in making the correct diagnosis and planning a proper therapeutic strategy. PMID:24025889

Capaccio, Pasquale; Marciante, Giulia Anna; Gaffuri, Michele; Spadari, Francesco

2013-01-01

412

Equine odontoclastic tooth resorption and hypercementosis.  

PubMed

A poorly described, painful disorder of incisor and canine teeth, variably causing periodontitis, with resorptive or proliferative changes of the calcified dental tissues, has recently been documented in aged horses. No plausible aetiopathogenesis for this syndrome has been recorded. Eighteen diseased teeth from eight horses were examined grossly and microscopically and showed the presence of odontoclastic cells by tartrate resistant acid phosphatase (TRAP) staining. A chronological sequence of odontoclastic resorption followed by hypercementosis was demonstrated and, consequently, the term equine odontoclastic tooth resorption and hypercementosis (EOTRH) is proposed for this disorder. EOTRH shares many features with similar dental syndromes described in humans and cats. An aetiological hypothesis proposes mechanical stress of the periodontal ligament as the initiating factor. PMID:19010701

Staszyk, Carsten; Bienert, Astrid; Kreutzer, Robert; Wohlsein, Peter; Simhofer, Hubert

2008-12-01

413

Unusual intraosseous transmigration of impacted tooth  

PubMed Central

Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed. PMID:22474648

Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima

2012-01-01

414

The clinical measurement of tooth colour and stain.  

PubMed

There are many contributory factors to tooth colour and different techniques for its measurement. The aim of this paper is to evaluate methods of tooth colour and stain measurement, with an emphasis on recent advances in objective clinical measurement techniques. The overall colour effect of natural teeth is created by a combination of light which is reflected and scattered by tooth enamel and the underlying dentine. Developmental defects of the dentition can affect the intrinsic discolouration of teeth, for example, amelogenesis imperfecta and dentinogenesis imperfecta. Extrinsic discolouration is predominantly caused by stain build up on a tooth surface from bacteria, foodstuffs or metalic compounds. Tooth colour and stain measurement are currently assessed using a wide range of measurement methods divided into subjective (visual shade matching) and objective instrumental assessment such as by colourimetry, spectrophotometry and digital image analysis. The most popular method of assessing tooth colour clinically is visual shade matching, as this approach is quick and simple to use. However, variation in results can occur as a consequence of the subjective nature of this method. The instrumental approaches including quantitative light-induced fluorescence remove or significantly reduce the subjective component. Image analysis appears to be the most suitable method for tooth colour measurement and further work is being carried out to establish this approach. PMID:17992918

Brook, A H; Smith, R N; Lath, D J

2007-10-01

415

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

416

Industrial Noise and Tooth Wear - Experimental Study  

PubMed Central

Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear. The effects of continuous exposure to industrial noise, a “stressor” agent, cannot be ignored and its effects on the teeth must be evaluated. Aims: The aim of this study was to ascertain the effects of industrial noise on dental wear over time, by identifying and quantifying crown area loss. Material and Methods: 39 Wistar rats were used. Thirty rats were divided in 3 experimental groups of 10 animals each. Animals were exposed to industrial noise, rich in LFN components, for 1, 4 and 7 months, with an average weekly exposure of 40 hours (8h/day, 5 days/week with the weekends in silence). The remaining 9 animals were kept in silence. The areas of the three main cusps of the molars were measured under light microscopy. Statistical analysis used: A two-way ANOVA model was applied at significance level of 5%. Results: The average area of the molar cusps was significantly different between exposed and non-exposed animals. The most remarkable differences occurred between month 1 and 4. The total crown loss from month 1 to month 7 was 17.3% in the control group, and 46.5% in the exposed group, and the differences between these variations were significant (p<0.001). Conclusions: Our data suggest that industrial noise is an important factor in the pathogenesis of tooth wear. PMID:25798052

Cavacas, Maria Alzira; Tavares, Vitor; Borrecho, Gonçalo; Oliveira, Maria João; Oliveira, Pedro; Brito, José; Águas, Artur; dos Santos, José Martins

2015-01-01

417

Co, Fe, and Ti Implants in InGaAs and Co Implants in InP at 200° C  

NASA Astrophysics Data System (ADS)

Elevated temperature (200° C) single- and multiple-energy Co implants in n-type InP, Co and Fe implants in n-type In0.53Ga0.47As, and Ti implants in p-type In0.53Ga0.47As were performed. For elevated temperature, single-energy Co and Fe implants, no satellite peaks at various locations like 0.8 R P, RP + ?RP, and 2 R P R P is the projected range and ? R P the straggle of the implant) are observed, in contrast to the case of room temperature implants. However, the outdiffusion of the implant is as severe as that in room temperature implantation for high temperature anneals. Indiffusion of the implant also occurs, but it is not as severe as the outdiffusion. High temperature annealing of Ti-implanted material results in a slight indiffusion of Ti, with minimal redistribution or outdiffusion. For all elevated temperature implants, the lattice quality of the annealed material is close to that of the virgin unimplanted material. For all ion species used in this study, resistivities close to the intrinsic limit are obtained in the implanted and annealed materials.

Rao, Mulpuri V.; Gulwadi, Sadanand M.; Mulpuri, Savitri; Simons, David S.; Chi, Peter H.; Caneau, C.; Hong, W.-P.; Holland, O. W.; Dietrich, Harry B.

1992-09-01

418

Effect of zinc ions on improving implant fixation in osteoporotic bone.  

PubMed

The application of titanium (Ti) and its alloys in tooth restoration and joint replacement for aged patients with unfavorable conditions is gaining popularity. Therefore, strategies aiming at improving the fixation of Ti-based implants are worth investigating. This study was designed to observe whether modification of Ti implants by zinc (Zn) could enhance the fixation capability in osteoporotic bone. Two kinds of implants, hydroxyapatite (HA) coated Ti and Zn-incorporated HA (ZnHA) coated Ti, were inserted into the femoral metaphysis longitudinally in ovariectomized (OVX) rats. Specimens were harvested and subjected to double fluorescence labeling examination at week 6 after surgery. At week 12, samples were evaluated with histomorphometry, micro-CT (?CT) analysis and biomechanical test. Compared to the HA coated implants, ZnHA coating improved mineral apposition rate (MAR) of peri-implant bone, which was revealed by double fluorescence labeling; bone area ratio (BA) and bone-to-implant contact (BIC) were also higher for the latter group by histomorphometry. ?CT images suggested that more bone mass was formed around the ZnHA coated implants as compared to the HA coated implants. Biomechanical push-out test showed that the ZnHA coated implants demonstrated higher strength of osseointegration than the HA group. The current study suggested that Zn ions could enhance bone formation and improve implant fixation in OVX rats. PMID:23971976

Li, Xudong; Li, Yunfeng; Peng, Shengcheng; Ye, Bin; Lin, Wei; Hu, Jing

2013-01-01

419

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

420

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

421

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

422

Chronic rhinorrhea revealing an actinomycotic rhinolithiasis with ectopic tooth.  

PubMed

Intranasal ectopic tooth is a rare nidus for a rhinolith where local infection may be concomitant. No description of the triple association 'actinomycotic rhinolithiasis ectopic tooth' could be found in the medical literature. Classically, the Actinomyces species are sensitive to regimens of penicillin from 6 to 12 months or longer. Immunocompetent patients can benefit from shorter courses of antibiotic therapy, such as ciprofloxacin, with a favourable outcome. The authors describe the case of a 25-year-old man who presented with an actinomycosis chronic discharge revealing actinomycosis associated with rhinolithiasis and ectopic tooth. They attempt to explain the likely mechanism of occurrence of this triple association. PMID:21865012

Zalagh, M; Akhaddar, A; Benariba, F

2012-03-01

423

Genome-Wide Association Study Reveals Multiple Loci Associated with Primary Tooth Development during Infancy  

Microsoft Academic Search

Tooth development is a highly heritable process which relates to other growth and developmental processes, and which interacts with the development of the entire craniofacial complex. Abnormalities of tooth development are common, with tooth agenesis being the most common developmental anomaly in humans. We performed a genome-wide association study of time to first tooth eruption and number of teeth at

Demetris Pillas; Clive J. Hoggart; David M. Evans; Paul F. OReilly; Kirsi Sipilä; Raija Lähdesmäki; Iona Y. Millwood; Marika Kaakinen; Gopalakrishnan Netuveli; David Blane; Pimphen Charoen; Ulla Sovio; Anneli Pouta; Nelson Freimer; Anna-Liisa Hartikainen; Jaana Laitinen; Sarianna Vaara; Beate Glaser; Peter Crawford; Nicholas J. Timpson; Susan M. Ring; Guohong Deng; Weihua Zhang; Mark I. McCarthy; Panos Deloukas; Leena Peltonen; Paul Elliott; Lachlan J. M. Coin; George Davey Smith; Marjo-Riitta Jarvelin

2010-01-01

424

The grinding tip of the sea urchin tooth exhibits exquisite control over calcite crystal orientation  

E-print Network

The grinding tip of the sea urchin tooth exhibits exquisite control over calcite crystal to the increasing hardness of the tooth from the periphery to the tip. Clearly the formation of the tooth, and the tooth tip in particular, is amazingly well controlled. The improved understanding of these structural

Gilbert, Pupa Gelsomina De Stasio

425

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

426

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

427

Fast image processing on chain board of inverted tooth chain  

NASA Astrophysics Data System (ADS)

Discussed ordinary image processing technology of inverted tooth chain board, including noise reduction, image segmentation, edge detection and contour extraction etc.. Put forward a new kind of sub-pixel arithmetic for edge orientation of circle. The arithmetic first did edge detection to image by Canny arithmetic, so as to enhance primary orientation precision of edge, then calculated gradient direction, and then interpolated gradient image (image that was detected by Sobel arithmetic) along gradient direction, last obtained sub-pixel orientation of edge. Performed two kinds of least-square fitting methods for line edge to getting its sub-pixel orientation, from analysis and experiments, the orientation error of improved least-square linear fitting method was one quarter of ordinary least-square linear fitting error under small difference of orientation time. The sub-pixel orientation of circle made resolution of CCD increase 42 tines, which enhanced greatly orientation precision of image edge. For the need of quick on-line inspection next step, integrated the whole environment containing image preprocess, Hough conversion of line, setting orientation & direction of image, sub-pixel orientation of line and circle, output of calculation result. The whole quick processing course performed without operator, processing tine of single part is less than 0.3 second. The sub-pixel orientation method this paper posed fits precision orientation of image, and integration calculation method ensure requirement of quick inspection, and lays the foundations for on-line precision visual measurement of image.

Liu, Qing-min; Li, Guo-fa

2007-12-01

428

Comparison of three different techniques for histological tooth preparation.  

PubMed

The histological processing of teeth is highly complicated because of containing both mineralized hard tissues and soft tissues. Depending on the type of decalcification agents used in processing, mild-to-severe deterioration in the tissue structure and inadequacies on clear staining of details by the histological stain may be observed. This study aims to compare the histological staining differences in the preparations from decalcified and undecalcified tooth roots by three different embedding materials and techniques. Following extraction, human single-rooted teeth crowns were cut off and roots were placed in 10% buffered neutral formalin. After fixation, roots were divided into two groups. One part of samples was decalcified in formic acid solution and the other was remained undecalcified. Decalcified roots were embedded in paraffin and glycol methacrylate (GMA)-based resin and undecalcified roots were embedded in methyl methacrylate (MMA)-based resin. Sections from all groups were stained with hematoxylin and eosin. The groups were compared in terms of general staining, brightness, density, density of the base stain, general morphology of cells, nuclear/cytoplasmic contrast, distinguish ability of pulp, odontoblast layer, predentin and dentin, preservation and traceability of dentinal tubule. In the preparations which were embedded into the MMA-based embedding material, an output lower than the paraffin group buthigher than the GMA-embedded group was provided. As a result, the best histological detail was obtained from the decalcified, paraffin-embedded sections. PMID:24497133

Keklikoglu, Nurullah; Akinci, Sevtap

2013-01-01

429

Accuracy of 3D scanners in tooth mark analysis.  

PubMed

The objective of this study was to compare the accuracy of contact and laser 3D scanners in tooth mark analysis. Ten dental casts were scanned with both 3D scanners. Seven linear measurements were made from the 3D images of dental casts and biting edges generated with DentalPrint© software (University of Granada, Granada, Spain). The uncertainty value for contact 3D scanning was 0.833 for the upper dental cast and 0.660 mm for the lower cast; similar uncertainty values were found for 3D-laser scanning. Slightly higher uncertainty values were obtained for the 3D biting edges generated. The uncertainty values for single measurements ranged from 0.1 to 0.3 mm with the exception of the intercanine distance, in which higher values were obtained. Knowledge of the error rate in the 3D scanning of dental casts and biting edges is especially relevant to be applied in practical forensic cases. PMID:25388960

Molina, Ana; Martin-de-las-Heras, Stella

2015-01-01

430

Vertical root fracture: preservation of the alveolar ridge using immediate implants.  

PubMed

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

431

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

432

Molar Tooth Diversity, Disparity, and Ecology in Cenozoic Ungulate Radiations  

Microsoft Academic Search

A classic example of adaptive radiation is the diversification of Cenozoic ungulates into herbivore adaptive zones. Their taxonomic diversification has been associated with changes in molar tooth morphology. Analysis of molar crown types of the Artiodactyla, Perissodactyla, and archaic ungulates (\\

Jukka Jernvall; John P. Hunter; Mikael Fortelius

1996-01-01

433

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2014 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

2014-04-01

434

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2010 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

2010-04-01

435

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2012 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture...

2012-04-01

436

Dickkopf-1 in Craniofacial Bone and Tooth Development  

E-print Network

result in osteopenia. Targeted expression of Dkk1 in dental epithelial cells leads to the formation of dysfunctional enamel knots and subsequent tooth defects during embryonic development. However, the direct role of Dkk1 in post-natal dentinogenesis...