Sample records for single tooth implant

  1. Three-dimensional location of the retaining screw axis for a cemented single tooth implant restoration.

    PubMed

    Wicks, Russell; Shintaku, Werner H; Johnson, Andrew

    2012-08-01

    Retrievability is a major concern with cemented versus screw-retained implant restorations. This article describes the use of cone beam radiography to help target and create a precise screw access opening for a loosened implant-supported single crown retained by cement to its abutment. PMID:22823426

  2. Cumulative survival rate and complication rates of single-tooth implant; focused on the coronal fracture of fixture in the internal connection implant.

    PubMed

    Cha, H-S; Kim, Y-S; Jeon, J-H; Lee, J-H

    2013-08-01

    This retrospective study evaluated the 5-year cumulative survival rate and complication rates of a 4·0-mm internal connection implant (MicroThread™ Osseospeed™, Astra Tech) installed for single-tooth restoration. The patients who were treated at Asan Medical Center between 2006 and 2007 were included in this study. A life table analysis was used to calculate the 5-year cumulative survival rate. Comparisons of cumulative survival rates among implant position (anterior, premolar and molar), jawbone (maxilla, mandible), gender and prosthesis type (screw-retained, cement-retained) were performed using the log-rank test. Post-loading complications were analysed using Fisher's exact test. Twelve of 136 implants (anterior; 22, premolar; 25, molar; 89) were lost during the loading period, and 11 were removed due to coronal fracture of fixture. The 5-year cumulative survival rate of the whole arch was 91·9%, and that of the molar region was 87·6%. Statistically significant differences were observed in cumulative survival rates among implant position (P = 0·037), whereas no statistically significant differences were observed among gender, jawbone, prosthesis type. Forty-seven of 114 (41·2%) implants in the posterior region showed post-loading complications, including coronal fracture of fixture and abutment screw loosening. PMID:23679929

  3. When is an implant ready for a tooth?

    PubMed

    Tupac, Robert G

    2003-12-01

    The capability of placing an osseointegrated implant at the time of tooth extraction and immediately placing a restoration on the implant depends upon a number of factors. This paper describes the traditional Brånemark protocol, the evolution of single-stage surgery, the guidelines for immediate placement, the measurement of implant stability, and the considerations critical to immediately loading. PMID:14736043

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2014-09-01

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

  6. When Is an Implant Ready for a Tooth?

    Microsoft Academic Search

    Robert G. Tupac

    2003-01-01

    The capability of placing an osseointe- grated implant at the time of tooth extraction and immediately placing a restoration on the implant depends upon a number of factors. This paper describes the traditional Brånemark protocol, the evolution of single-stage surgery, the guidelines for immediate placement, the measurement of im- plant stability, and the considerations critical to immediately loading. t

  7. A Review of Factors Influencing Treatment Planning Decisions of Single-tooth Implants versus Preserving Natural Teeth with Nonsurgical Endodontic Therapy

    Microsoft Academic Search

    Mian K. Iqbal; Syngcuk Kim

    2008-01-01

    One of the major issues confronting the contemporary dental clinician is the treatment decision between extracting a tooth with placement of a dental implant or preserving the natural tooth by root canal treatment. The factors that dictate the correct selection of one procedure over the other for each particular case are not yet established by randomized controlled studies. The aim

  8. Peri-Implant Diseases

    MedlinePLUS

    ... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

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

    PubMed

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

    2012-08-01

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

  10. Prognosis and evaluation of tooth damage caused by implant fixtures

    PubMed Central

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

    2013-01-01

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

  11. Hydroxyapatite-coated tooth implants by laser

    NASA Astrophysics Data System (ADS)

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

    1996-09-01

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

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

    PubMed

    Michalakis, Konstantinos X; Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

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

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

    PubMed Central

    Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

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

  14. Qualitative analysis of stress distribution in tooth-implant and implant-supported prosthesis by means of holography interferometry method

    Microsoft Academic Search

    JOSE EDUARDO CHORRES; CARLA UONO; MARCO ANTÔNIO GIOSO; LUIS BATISTA

    2006-01-01

    Natural teeth an dd ental implants cause non- uniform distribution of stress when connected in prosthesis. Understanding of biomechanica lb e- havior is necessary for an adequate choice and construction of this type of rehabilitation. The purpose of this study was to compare the stress distribution between implant and tooth-implant- supported prosthesis under static load by means of holographic interferometry

  15. Single-Tooth Modeling for 3D Dental Model

    PubMed Central

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

    2010-01-01

    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

  16. Rehabilitation using single stage implants

    PubMed Central

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

    2009-01-01

    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

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

    PubMed

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

    2015-01-01

    The purpose of this study was to clinically and radiographically compare implant-connected and tooth-connected implant-supported fixed-detachable mandibular partial dentures. Twenty partially edentulous patients (age range: 25 to 50 years) with mandibular Kennedy Class II configurations were equally divided into two groups receiving a three-unit, fixed-detachable, screw-retained partial denture. Group 1 comprised patients with unilateral missing mandibular molars and premolars. Two implants were placed at the mandibular first premolar and first molar areas. Group 2 comprised patients with missing mandibular molars and second premolars. An implant was placed at the mandibular first molar area, the first premolar was prepared, and a coping was cemented to the tooth with permanent cement. Each case was evaluated clinically and radiographically at baseline (partial denture insertion) and after 6, 12, and 24 months. Data were collected and statistically analyzed using repeated-measures one-way and two-way analysis of variance tests. There was no statistically significant difference between the two groups (P > .05). The implant-tooth-supported prosthesis provided an equally predictable treatment option compared to the totally implant-supported prosthesis in terms of implant survival and loss of marginal bone. PMID:25909533

  18. Bridges supported by free-standing implants versus bridges supported by tooth and implant. A five-year prospective study.

    PubMed

    Olsson, M; Gunne, J; Astrand, P; Borg, K

    1995-06-01

    The clinical question at issue, whether it is possible to combine implants and natural teeth via fixed bridges, is of current interest. The treatment of the subjects of this prospective study was performed between June 1984 and December 1986. This article presents the 5-year results of the study. The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the mandible and a complete maxillary denture. All 23 patients were provided with implants ad modum Brånemark in each mandibular quadrant. One side was randomized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant; the other side received a free-standang bridge on 2 implants. The fixture survival rate was 88%. No difference was found between the two sides. Bridge stability was 89% for the implant bridges and 91% for the combination bridges. The change in marginal bone level at the implants was small during the 5-year follow up period (on average 0.1-0.3 mm) and with no difference between the two sides. In conclusion, it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth-implant fixed bridges compared with implant-supported bridges. PMID:7578781

  19. The use of a dental implant as an abutment in three unit implant-tooth supported fixed partial denture: a case report and 32 month follow-up

    Microsoft Academic Search

    DF Clarke; ST Chen; AJG Dickinson

    2006-01-01

    The combined use of dental implants and teeth as abutments in fixed partial dentures may offer advantages to both patients and practitioners in certain clinical situations. An implant-tooth retained prosthesis may reduce surgical intervention and cost to the patient. It may also mean that anatomical restrictions to the provision of an implant-retained fixed prosthesis may be overcome. In this case

  20. Tissue reaction to submerged ceramic tooth root implants. An experimental study in monkeys.

    PubMed

    Pedersen, K N

    1979-01-01

    Tooth root replica implants made from alumina ceramic material of solid structure coated with a porous layer, were used as dental implants in monkeys. The porous coating was 1/2 mm thick and had pore sizes within 50--200 microns range, with a 30% degrees of porosity. Tne implants were inserted into prepared sockets in the mandible of 5 Cercopithecus monkeys. After submerged implantation periods varying from 5 to 15 weeks, a perforating steel post was introduced through the covering gingiva into the artificial root canal of the implants. The animals were sacrificed after 6 weeks, 2, 3 and 4 months. Three out of the total number of 10 implants were lost. The remaining 7 specimens were retrieved for histologic and microradiographic examination. Fibrous and mineralized tissue ingrowth of the porous layer of the implants was found. No adverse reactions of the adjacent bone were demonstrable. The implants became anchored to the host and no epithelial downgrowth along the ceramic was found. PMID:121514

  1. Use of an Implant O-Ring Attachment for the Tooth Supported Mandibular Overdenture: A Clinical Report

    PubMed Central

    Guttal, Satyabodh S.; Tavargeri, Anand K.; Nadiger, Ramesh K.; Thakur, Srinath L.

    2011-01-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, preservation of these teeth for overdentures can improve retention and stability. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with bar and O-ring attachment. A splinted bar supported the prosthesis and an O-ring retained the denture. PMID:21769276

  2. The clinical success of tooth- and implant-supported zirconia-based fixed dental prostheses. A systematic review.

    PubMed

    Le, M; Papia, E; Larsson, C

    2015-06-01

    The aim was to make an inventory of the current literature on the clinical performance of tooth- or implant-supported zirconia-based FDPs and analyse and discuss any complications. Electronic databases, PubMed.gov, Cochrane Library and Science Direct, were searched for original studies reporting on the clinical performance of tooth- or implant-supported zirconia-based FDPs. The electronic search was complemented by manual searches of the bibliographies of all retrieved full-text articles and reviews, as well as a hand search of the following journals: International Journal of Prosthodontics, Journal of Oral Rehabilitation, International Journal of Oral & Maxillofacial Implants and Clinical Oral Implants Research. The search yielded 4253 titles. Sixty-eight potentially relevant full-text articles were retrieved. After applying pre-established criteria, 27 studies were included. Twenty-three studies reported on tooth-supported and 4 on implant-supported FDPs. Five of the studies were randomised, comparing Y-TZP-based restorations with metal-ceramic or other all-ceramic restorations. Most tooth-supported FDPs were FDPs of 3-5 units, whereas most implant-supported FDPs were full arch. The majority of the studies reported on 3- to 5-year follow-up. Life table analysis revealed cumulative 5-year survival rates of 93·5% for tooth-supported and 100% for implant-supported FDPs. For tooth-supported FDPs, the most common reasons for failure were veneering material fractures, framework fractures and caries. Cumulative 5-year complication rates were 27·6% and 30·5% for tooth- and implant-supported FDPs, respectively. The most common complications were veneering material fractures for tooth- as well as implant-supported FDPs. Loss of retention occurred more frequently in FDPs luted with zinc phosphate or glass-ionomer cement compared to those luted with resin cements. The results suggest that the 5-year survival rate is excellent for implant-supported zirconia-based FDPs, despite the incidence of complications, and acceptable for tooth-supported zirconia-based FDPs. These results are, however, based on a relatively small number of studies, especially for the implant-supported FDPs. The vast majority of the studies are not controlled clinical trials and have limited follow-up. Thus, interpretation of the results should be made with caution. Well-designed studies with large patient groups and long follow-up times are needed before general recommendations for the use of zirconia-based restorations can be provided. PMID:25580846

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

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

    2014-01-01

    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

  5. Clinical evaluation of implant survival based on size and site of placement: A retrospective study of immediate implants at single rooted teeth sites

    PubMed Central

    Ramalingam, Sundar; Al-Hindi, Maryam; Al-Eid, Raniah Abdullah; Nooh, Nasser

    2015-01-01

    Objectives This retrospective clinical study sought to evaluate the survival of immediate implants placed at maxillary and mandibular single-rooted tooth extraction sites and to determine the relationship among implant size, placement site, and implant survival. Methods Between January 2010 and June 2011, 85 patients (33 males, 52 females; mean age: 45 years) underwent immediate implant placement after extraction of single-rooted teeth. All implants were restored between 12 and 14 weeks after implant placement. The implant survival and its relationship with implant size and implantation site were evaluated by odds ratios (ORs). Results Implants were placed at the following sites: upper central incisor (UCI, n = 35), upper lateral incisor (ULI, n = 27), upper second premolar (U2ndP, n = 36), lower incisor (LI, n = 53), and lower premolar (LP, n = 22). Implants of the following sizes were used: 5 × 10 mm (n = 24), 5 × 8 mm (n = 21), 4.3 × 10 mm (n = 77), 4.3 × 8 mm (n = 36), 3.5 × 10 mm (n = 12), and 3.5 × 8 mm (n = 3). After a mean follow-up time of 47 months, the overall implant survival rate was 96%. Survival rate was highest at the LI site (98.1%) and lowest at the ULI site (92.6%). All of the 5-mm implants survived (100%), as did most of the 4.3 × 10 mm implants (96.1%). Implants of 4.3 × 8 mm and 3.5 × 10 mm were the least successful (91.7%). Mandibular implants had a better survival rate (97.3%) than maxillary implants (94.9%). There was no significant OR of increased survival for any particular implant size or site. Conclusions Immediate implant placement in fresh extraction sockets can give predictable clinical outcomes, regardless of the implant size and site of placement.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

    PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis. PMID:22737309

  8. Single Color Centers Implanted in Diamond Nanostructures

    E-print Network

    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

    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.

  9. Long-term evaluation of single crystal sapphire implants as abutments in fixed prosthodontics.

    PubMed

    Fartash, B; Arvidson, K

    1997-02-01

    49 patients participated in a prospective study of treatment of total or partial edentulism with fixed prosthodontics supported by Bioceram sapphire implants. 15 patients were treated for maxillary or mandibular edentulism, and 7 for a missing maxillary anterior tooth. The remaining 27 patients, with Applegate-Kennedy Class I-IV residual dentitions, were treated with fixed bridges supported by free-standing implants, or bridges supported by teeth and implants. Implant success, prosthesis stability, radiographic marginal bone level as well as parameters for peri-implant health were evaluated. The study began in 1982, and clinical treatment of the last patients was completed in 1988, i.e., a follow-up period ranging from 7 to 13 years. Of the patients treated for total mandibular edentulism, one implant fractured after 6 years in situ. The bone implant score (BIS) values for those implants were at the time for the bridge cementation 63.5 +/- 1.4 and at 1, 2, 3 and 5 year follow-ups 62.1 +/- 1.4, 61.9 +/- 1.5, 61.5 +/- 1.6, and 60.95 +/- 1.3, respectively. The success rate was 100%, 100% and 97.7% for the mandible at 3, 5 and 10 years, respectively. Of the 7 edentulous patients treated with maxillary fixed bridges, 6 implants in 1 patient had to be removed after 1 year in service. Another 2 patients lost all their implants, 6 each, after 36 months. 6 implants in the 4th patient did not fulfil the criteria for success and were rated as failures at the four year follow-up. The success rate was thus 58.1%, 44.2% and 44.2% for the maxilla at 3, 5 and 10 year follow-ups, respectively. Of the 7 patients in whom single missing teeth were replaced, 1 implant in the premolar region was lost during the 1st year post-operatively, but no other complications or changes in BIS were observed. Of the 27 patients treated for partial edentulism (56 implants total) 1 implant, of a 4-unit free standing maxillary bridge fractured after 6 years and was later replaced. There were no statistically significant differences in BIS changes for the implants when used as abutments for partial maxillary or mandibular edentulism. The cumulative success rates for the implants in the partially maxilla were 96.3, 92.6 and 92.6 at the 3, 5 and 10 years respectively and 100% in the mandible over the whole period. PMID:9586457

  10. Anterior Sectional Twin Bracket Appliance – Innovative Use for Correction of Single Tooth Crossbite: A Case Report with Biomechanics

    PubMed Central

    Raghav, Pradeep; Reddy, Munish C; Kanwal, Ritika

    2015-01-01

    ABSTRACT Anterior sectional twin bracket appliance (ASTBA) is a sectional mechanism that involves two brackets on upper central incisors. This appliance is previously been used for correction of rotated incisors and midline spacing. But, detail biomechanics for single tooth crossbite correction is not previously explained. Here, in this article, we are presenting a detailed biomechanics of ASTBA for anterior single tooth crossbite correction along with case report. How to cite this article: Verma RK, Raghav P, Reddy MC, Kanwal R. Anterior Sectional Twin Bracket Appliance– Innovative Use for Correction of Single Tooth Crossbite: A Case Report with Biomechanics. Int J Clin Pediatr Dent 2015;8(1): 66-69.

  11. Hinged Single Piece Putty Index for Preclinical Demonstration of Tooth Preparation for Fixed Partial Dentures and Crowns

    PubMed Central

    Kumar, Shallabh

    2015-01-01

    Introduction: Different types of indices are being used for assessment of tooth preparation. All these indices are used to visualize tooth preparations in a particular plane. A single versatile index which could help to visualize tooth preparations in different planes is non-existent. The need for fabrication of such an index and its reliability is of utmost important to provide quality tooth preparations. Purpose: The purpose of the study is to fabricate a hinged single piece sectioned index which could be used to visualize tooth preparation in different planes and check its reliability in-vitro on phantom models. Materials and Methods: Ten preclinical students were selected in random for preparing three teeth each. The three teeth preparations are classified as Group A, Group B and Group C based on the non-usage of index, usage of sectioned index and hinged single piece sectioned index respectively. Students were made to do provisional restorations after the tooth preparations. Then a questionnaire was given to students to score the duration/accuracy/comfort during tooth preparation and duration/accuracy of provisional restorations for each of the Groups A,B and C. Results: In Group C, 90% of students found the final preparation to be very accurate. The time taken for fabrication of provisional restoration using sectioned hinged index by 60% of Group C students was 20 to 30 min. Conclusion: This hinged index is a viable option when accuracy of tooth preparation and speedy fabrication of provisional restoration is required. PMID:26023634

  12. A systematic review of the clinical performance of CAD\\/CAM single-tooth restorations

    Microsoft Academic Search

    J. G. Wittneben; R. F. Wright; H. P. Weber; G. O. Gallucci

    2009-01-01

    PURPOSE: This systematic review sought to determine the long-term clinical survival rates of single-tooth restorations fabricated with computer-aided design\\/computer-assisted manufacture (CAD\\/CAM) technology, as well as the frequency of failures depending on the CAD\\/CAM system, the type of restoration, the selected material, and the luting agent. MATERIALS AND METHODS: An electronic search from 1985 to 2007 was performed using two databases:

  13. Backing up Medium Current Implanters using Single Wafer High Energy Implanter for Manufacturing Efficiency

    NASA Astrophysics Data System (ADS)

    Sun, H. L.; Lee, Woojin; Xu, Knight; Tsun, H. Y.; Peng, K. T.; Juang, L. S.; Tseng, H. P.

    2006-11-01

    Today most high volume manufacturing fabs are experiencing an inefficient distribution of resources between medium current (MC) and high energy (HE) implanters. The utilization levels of medium current implanters and high energy implanters differ greatly due to increasing amounts of medium current implant recipes. Medium current implanters are very highly utilized, while high energy implanters are not used as much. Thus, the high energy implant tools can be used to optimize manufacturing efficiency and production cost reduction by backing up the medium current tools. Traditionally, there were only well implants that can be processed on both single wafer medium current (SWMC) and batch HE implanters. However, by using the Varian VIISta 3000HP Single Wafer High Energy implanter (SWHE) with high tilt and true zero degree implantation capability, Vt, anti-punch-through and pocket/ halo implants can also be used as backups. The data of the electrical function and yield comparison between SWHE VIISta 3000HP and SWMC EHP500 was shown to be compatible. The throughput was also evaluated to match the productivity of medium current implanters which are higher than the batch tools. This paper shows that the SWHE can maximize the manufacturing efficiency and minimize the production cost.

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

    Microsoft Academic Search

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

    2002-01-01

    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

  15. A study of single crystal zirconia implanted with platinum ions

    Microsoft Academic Search

    D.-Z. Xie; D.-Z. Zhu; D.-X. Cao; Z.-Y. Zhou

    1997-01-01

    Single crystal samples of (100) oriented cubic (yttria stabilized zirconia)(YSZ) were implanted with 105 and 160 keV platinum ions, using a metal vapor vacuum are (MEVVA) high current ion implanter, to nominal doses of 2 × 1016 ions\\/cm2 and 5 × 1016 ions\\/cm2, respectively, at room temperature (RT). The implanted samples were annealed isothermally in air ambient at 850°C and

  16. A study of single crystal zirconia implanted with platinum ions

    Microsoft Academic Search

    Dong-zhu Xie; De-zhang Zhu; De-xin Cao; Zhu-yao Zhou

    1997-01-01

    Single crystal samples of ?1 0 0? oriented cubic (yttria stabilized zirconia) (YSZ) were implanted with 105 and 160 keV platinum ions, using a metal vapor vacuum arc (MEVVA) high current ion implanter, to nominal doses of 2 × 1016ions\\/cm2 and 5 × 1016ions\\/cm2, respectively, at room temperature (RT). The implanted samples were annealed isothermally in air ambient at 850°C

  17. Prognosis of single molar implants: a retrospective study.

    PubMed

    Kim, Young-Kyun; Kim, Su-Gwan; Yun, Pil-Young; Hwang, Jung-Won; Son, Mee-Kyoung

    2010-08-01

    The purpose of this study was to evaluate the short- and mid-term prognosis of maxillary and mandibular single molar implants, prosthetic complications, and factors mediating the effects seen on them. Eighty-seven patients were enrolled consecutively in this study and 96 implants were placed into a single molar defect site by one oral and maxillofacial surgeon from March 2004 to December 2006. Primary osseointegration failure developed in two implants and delayed implant failure occurred at four implants. The fraction surviving interval was 97% to 100%, and at the last follow-up observation, the cumulative survival rate was 91.1%. All failed implants occurred in second molar sites, and the failure rate, according to implant site, showed a significant difference. Prosthetic complications, such as screw loosening, showed a significant correlation to the mesiodistal cantilever. Furthermore, crestal bone loss 3 years after loading was 0.2 mm on average and a very stable result was obtained. Based on the results, the risk of failure for maxillary and mandibular single molar implants is high and the possibility of developing prosthetic complications during loading is also high. Therefore, to minimize the cantilever, implants must be placed precisely and followed carefully and maintained for a long period of time. PMID:20664842

  18. Single Visit Apexification Procedure of a Traumatically Injured Tooth with a Novel Bioinductive Material (Biodentine)

    PubMed Central

    Jingarwar, Mahesh Madhukar; Pathak, Anuradha

    2015-01-01

    ABSTRACT Aim of this article is to present a case wherein single visit apexification of a traumatically injured tooth was done with a bioactive material–Biodentine. An injury sustained between the ages of 6 and 14 can adversely affect pulpal health and interrupt root development. In these instances, apexification is generally the preferred treatment. A 10 years old male patient presented with coronal fracture of the left upper central incisor. Clinical and radiographic assessment showed negative pulpal sensibility and arrested apical root development. Artificial apical barrier induction with Biodentine followed by endodontic treatment and prosthetic rehabilitation was decided as the line of treatment. To conclude, this bioactive and biocompatible calcium-based cement can regenerate damaged dental tissues and represents a promising alternative to the conventional multivisit apexification technique. Clinical significance: Biodentine which is a biologically active cement can be an efficient alternative to the conventional apexification materials which were hitherto recommended. How to cite this article: Bajwa NK, Jingarwar MM, Pathak A. Single Visit Apexification Procedure of a Traumatically Injured Tooth with a Novel Bioinductive Material (Biodentine). Int J Clin Pediatr Dent 2015;8(1):58-61.

  19. Histological characteristics of peri-implant mucosa around Brånemark and single-crystal sapphire implants.

    PubMed

    Arvidson, K; Fartash, B; Hilliges, M; Köndell, P A

    1996-03-01

    Soft tissues surrounding Brånemark titanium implants and single crystal sapphire implants were studied by conventional light- and transmission electron microscopy and by immunohistochemical markers for cytokeratin, protein S-100, Factor VIII and KP1. Histological sections of biopsies obtained from clinically healthy peri-implant mucosa were separated into a keratinized outer implant epithelium and an inner, non-keratinized epithelium, both immunoreactive towards cytokeratin. The inner implant epithelium terminated in a junctional epithelium, apically not a few cell layers thick. The cells adjacent to the implant showed a condensed cytoplasm, resembling hemidesmosomes. In the underlying connective tissue, rich in fibroblasts and factor VIII immunoreactive blood vessels, the bundles of collagen ran in different directions. S-100 immunoreactive nerve structures were more frequently found beneath the outer than the inner implant epithelium. Inflammatory cell infiltrates, some KP1 positive, were observed in the apical parts of the inner implant epithelium. S-100 positive Langerhans' cells were present mainly within the the outer implant epithelium. For the two implant systems, the techniques disclosed no qualitative structural differences in the adjacent soft tissues. PMID:9002817

  20. Immediate provisionalization and nonfunctional loading of a single implant in the maxillary esthetic zone: a clinical presentation and parameters for consideration.

    PubMed

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

    2013-01-01

    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

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

    PubMed Central

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

    2013-01-01

    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

  2. Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices

    PubMed Central

    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

    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

  3. Spatial hearing with a single cochlear implant in late-implanted adults.

    PubMed

    Nava, Elena; Bottari, Davide; Bonfioli, Francesca; Beltrame, Millo Achille; Pavani, Francesco

    2009-09-01

    We assessed sound localisation abilities of late-implanted adults fitted with a single cochlear implant (CI) and examined whether these abilities are affected by the duration of implant use. Ten prelingually and four postlingually deafened adults who received a unilateral CI were tested in a sound-source identification task. Above chance performance was observed in those prelingual CI recipients who had worn their implant for longer time (9 years on average), revealing some monaural sound localisation abilities in this population but only after extensive CI use. On the contrary, the four postlingual recipients performed equal or better with respect to the best prelingual participants despite shorter experience with the monaural implant (11 months on average). Our findings reveal that some sound localisation ability can emerge in prelingually deafened adults fitted with a single implant, at least in a controlled laboratory setting. This ability, however, appears to emerge only after several years of CI use. Furthermore, the results of four postlingually deafened adults suggest that early experience with auditory cues may result in more rapid acquisition of spatial hearing with a single CI. PMID:19539018

  4. A study of single crystal zirconia implanted with platinum ions

    NASA Astrophysics Data System (ADS)

    Xie, Dong-zhu; Zhu, De-zhang; Cao, De-xin; Zhou, Zhu-yao

    1997-11-01

    Single crystal samples of <1 0 0> oriented cubic (yttria stabilized zirconia) (YSZ) were implanted with 105 and 160 keV platinum ions, using a metal vapor vacuum arc (MEVVA) high current ion implanter, to nominal doses of 2 × 10 16ions/cm 2 and 5 × 10 16ions/cm 2, respectively, at room temperature (RT). The implanted samples were annealed isothermally in air ambient at 850°C and 1100°C from 4 to 12 h. Rutherford Backscattering Spectrometry and Channeling (RBS-C) of 2 MeV He ions has been used to study the depth distribution of lattice damage and implant, as well as the annealing behavior. X-ray diffraction (XRD) is employed to analyze the crystallite of implanted platinum. Both as-implanted samples do not show an amorphous phase. The Pt depth profile was almost unchanged for all samples during annealing at 850°C and 1100°C. For the 160 keV implanted sample no loss of Pt was observed after annealing at 1100°C. XRD results provide evidence for the formation of a monoclinic phase of ZrO 2 in the damage region after 1100°C annealing. For all annealed samples, Pt <2 0 0> preferred orientation crystallites were observed by XRD, while the Pt <1 1 1> peak was almost not visible for 850°C annealed samples.

  5. Single and Multiple Microphone Noise Reduction Strategies in Cochlear Implants

    PubMed Central

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

    2012-01-01

    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

  6. Optima XE Single Wafer High Energy Ion Implanter

    SciTech Connect

    Satoh, Shu; Ferrara, Joseph; Bell, Edward; Patel, Shital; Sieradzki, Manny [Axcelis Technologies, Inc. 108 Cherry Hill Drive, Beverly, MA 01915 (United States)

    2008-11-03

    The Optima XE is the first production worthy single wafer high energy implanter. The new system combines a state-of-art single wafer endstation capable of throughputs in excess of 400 wafers/hour with a production-proven RF linear accelerator technology. Axcelis has been evolving and refining RF Linac technology since the introduction of the NV1000 in 1986. The Optima XE provides production worthy beam currents up to energies of 1.2 MeV for P{sup +}, 2.9 MeV for P{sup ++}, and 1.5 MeV for B{sup +}. Energies as low as 10 keV and tilt angles as high as 45 degrees are also available., allowing the implanter to be used for a wide variety of traditional medium current implants to ensure high equipment utilization. The single wafer endstation provides precise implant angle control across wafer and wafer to wafer. In addition, Optima XE's unique dose control system allows compensation of photoresist outgassing effects without relying on traditional pressure-based methods. We describe the specific features, angle control and dosimetry of the Optima XE and their applications in addressing the ever-tightening demands for more precise process controls and higher productivity.

  7. Treatment strategies for infraoccluded dental implants.

    PubMed

    Zitzmann, Nicola U; Arnold, Dario; Ball, Judith; Brusco, Daniel; Triaca, Albino; Verna, Carlalberta

    2015-03-01

    Single-tooth implants in the maxillary anterior region have the highest risk of esthetic complications from infrapositioning due to continuing maxillary growth and the eruption of adjacent teeth. Although the placement of anterior single-tooth implants should normally be postponed, particularly girls and young women with a hyperdivergent growth pattern, if an infraposition of an implant is present, then thorough examination and strategic planning are required. According to the severity, the strategic treatment options are as follows: simple retention; adjustment or replacement of the implant restoration, possibly including adjacent teeth; surgical implant repositioning by segmental osteotomy combined with osseodistraction; or submergence or removal of the implant. With the patient presented, an interdisciplinary approach that combined orthodontic alignment, surgical segmental osteotomy, distraction osteogenesis, and restorative features offered the opportunity to realign the adjacent teeth into the arch and to harmonize the gingival contour by means of continuous soft tissue enlargement and adaptation. PMID:25444288

  8. A Conservative Treatment Approach to Replacing a Missing Anterior Tooth

    PubMed Central

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

    2014-01-01

    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

  9. Dose Control System in the Optima XE Single Wafer High Energy Ion Implanter

    SciTech Connect

    Satoh, Shu; Yoon, Jongyoon; David, Jonathan [Axcelis Technologies, Inc, 108 Cherry Hill Drive, Beverly, MA 01915 (United States)

    2011-01-07

    Photoresist outgassing can significantly compromise accurate dosimetry of high energy implants. High energy implant even at a modest beam current produces high beam powers which create significantly worse outgassing than low and medium energy implants and the outgassing continues throughout the implant due to the low dose in typical high energy implant recipes. In the previous generation of high energy implanters, dose correction by monitoring of process chamber pressure during photoresist outgassing has been used. However, as applications diversify and requirements change, the need arises for a more versatile photoresist correction system to match the versatility of a single wafer high energy ion implanter. We have successfully developed a new dosimetry system for the Optima XE single wafer high energy ion implanter which does not require any form of compensation due to the implant conditions. This paper describes the principles and performance of this new dose system.

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

    PubMed Central

    Moslehifard, Elnaz; Farid, Farzaneh

    2014-01-01

    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

  11. Cochlear implantation and management of chronic suppurative otitis media: single stage procedure?

    PubMed

    Basavaraj, S; Shanks, M; Sivaji, N; Allen, Agnes A

    2005-10-01

    In a series of 360 patients who underwent cochlear implantation at our center, four patients (five procedures) had cochlear implantation with obliteration of the mastoid cavity and management of cholesteatoma as a single-staged procedure. Three patients were bilaterally deaf secondary to CSOM and had bilateral mastoid cavities, and in one patient congenital cholesteatoma was identified during cochlear implantation. A mastoidectomy or revision mastoidectomy with obliteration of the mastoid cavity and cochlear implantation was performed as a single stage procedure. Cholesteatoma reoccurred in one patient 9 years after cochlear implantation. Surgical procedures, complications, follow-up and outcomes are discussed. PMID:15756568

  12. Accurate Dose Control with Pressure Compensation System on Single-Wafer Ion Implanters

    SciTech Connect

    Sano, Makoto; Yamada, Tatsuya; Sato, Fumiaki; Tsukihara, Mitsukuni; Sugitani, Michiro [SEN Corporation, an SHI and Axcelis Company 1501 Imazaike, Saijo, Ehime, 799-1362 (Japan)

    2008-11-03

    On ion implanters, dosimetry is generally controlled by monitoring an electrical current detected with Faraday cup(s) instead of the actual number of dopants. In some cases, ions in a beam undergo charge exchange phenomenon, interacting with residual gas molecules in a beamline. This charge exchange of ions causes variations of the detected beam currents which result in inaccurate dosimetry of implanted dopants. We will introduce to you a system similar to Pressure Compensation of the batch-type ion implanters to single-wafer ion implanters, that is, the SHX high current ion implanter and the MC3-II medium current ion implanter. The system converts the beam current detected with Faraday cups to an adequate value for dose control as a function of beamline pressure and brings accurate dosimetry also in these single-wafer ion implanters.

  13. Ferromagnetism in Mn-implanted ZnO:Sn single crystals D. P. Nortona)

    E-print Network

    Hebard, Arthur F.

    Ferromagnetism in Mn-implanted ZnO:Sn single crystals D. P. Nortona) and S. J. Pearton Department 21 November 2002 We have investigated the magnetic properties of Mn-implanted n-type ZnO single should be possible in manganese-doped p-type ZnO, although Mn-doped n-type ZnO should

  14. Who Is an Implant Candidate?

    MedlinePLUS

    ... interested in replacing a missing tooth or teeth, dental implants may be an option for you. Most people ... restorative dentist will make the crowns, bridges or dentures that the implant or implants will support. Your ...

  15. Mechanism of apatite formation on hydrogen plasma-implanted single-crystal silicon

    Microsoft Academic Search

    Xuanyong Liu; Ricky K. Y. Fu; Paul K. Chu; Chuanxian Ding

    2004-01-01

    Hydrogen is implanted into single-crystal silicon wafers using plasma ion immersion implantation to improve the surface bioactivity and the mechanism of apatite formation is investigated. Our micro-Raman and transmission electron microscopy results reveal the presence of a disordered silicon surface containing Si–H bonds after hydrogen implantation. When the sample is immersed in a simulated body fluid, the Si–H bonds on

  16. Mechanism of apatite formation on hydrogen plasma-implanted single-crystal silicon

    Microsoft Academic Search

    Xuanyong Liu; Ricky K. Y. Fu; Paul K. Chu; Chuanxian Ding

    2004-01-01

    Hydrogen is implanted into single-crystal silicon wafers using plasma ion immersion implantation to improve the surface bioactivity and the mechanism of apatite formation is investigated. Our micro-Raman and transmission electron microscopy results reveal the presence of a disordered silicon surface containing Si-H bonds after hydrogen implantation. When the sample is immersed in a simulated body fluid, the Si-H bonds on

  17. Tooth Numbering

    MedlinePLUS

    ... tooth on the lower right would be T. Palmer Notation Method Adults In this system, the mouth ... the upper right quadrant. Children In children, the Palmer Notation System uses uppercase letters instead of numbers. ...

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

    PubMed Central

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

    2010-01-01

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

  19. Mandibular overdentures anchored to single implants: A five-year prospective study

    Microsoft Academic Search

    Giampiero Cordioli; Zeina Majzoub; Stefano Castagna

    1997-01-01

    Statement of problem. It is unknown what minimum number of implants are required to satisfactorily support and retain a mandibular overdenture.Purpose. The purpose of this study was to evaluate a treatment modality by using mandibular overdentures anchored to single implants in a geriatric patient population.Material and methods. Twenty-one patients with a mean age of 74.2 years were treated with single

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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.

  1. RECONSTRUCTION OF 3D TOOTH IMAGES S. Buchaillard1

    E-print Network

    Paris-Sud XI, Université de

    , and treatment simulations. For example, a dental implant can be inserted into the jawbone when a tooth on the other side of the jaw to define a 3D rep- resentation of the missing tooth could result in an implant tomography (CT) is the most efficient way of generating 3D objects. However, CT imag- ing of dental patients

  2. Long term comparison between single stage Baerveldt and Ahmed glaucoma implants in pediatric glaucoma

    PubMed Central

    El Gendy, Nehal M.S.; Song, Jonathan C.

    2012-01-01

    Purpose To compare the long term intraocular pressure control in pediatric glaucoma patients who underwent single stage Baerveldt glaucoma valve and Ahmed glaucoma valve S2 implantation. Study design A retrospective study was conducted to analyze the data of patients with single stage Baerveldt glaucoma valve and Ahmed valve implantation at Children Hospital Los Angeles. Methods Medical records of patients were reviewed retrospectively and divided into two groups. All cases received single stage valve implantation in which the tube was inserted primarily into the anterior chamber. In cases with Baerveldt implants, the silicone tube was ligated near its plate location with a single absorbable suture. Group 1 included patients with Baerveldt glaucoma implant model BG 101–350, while group 2 included patients with Ahmed valve implant model S-2. Patients’ data collected ranged over the period from 2001 to 2008. The minimum follow up period was 6 month; maximum follow up period was 8 years. All patients were below 18 years of age. Success was considered if last postoperative IOP was between 8 and 24 mm Hg (with or without medications), no additional glaucoma surgery after valve implantation, and absence of visually significant complications. Results Group 1 included 20 cases and group 2 included 11 cases. Long term success rate based on criterion defined was 80% for group 1 (Baerveldt) with average IOP postoperatively on last follow-up of 19.6 mm Hg. In group 2 (Ahmed), average postoperative pressure was 24 mm Hg with 6 out of 11 considered successful based on criterion giving 54.5% success rate. Conclusion In the long term, single stage Baerveldt implantation appears to control pressure well in pediatric glaucoma. PMID:23961013

  3. Single Word and Sentence Intelligibility in Children with Cochlear Implants

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  5. Structural and chemical characteristics and oxidation behaviour of chromium-implanted single crystal silicon carbide

    Microsoft Academic Search

    H. Du. Z. Yang; M. Libera; D. C. Jacobson; Y. C. Wang; R. F. Davis

    1995-01-01

    High-dose chromium implantation resulted in complex changes in the structure, chemistry, and oxidation behaviour of beta-type\\u000a single-crystal silicon carbide. Detailed analytical studies indicated that, in addition to the primary process of surface\\u000a doping, chromium implantation of silicon carbide to 3.901017 ions cm?2 at 200 keV was accompanied by many secondary processes such as surface sputtering, lattice damaging, and silicon depletion\\/carbon

  6. Implants

    MedlinePLUS

    ... They are used to support crowns , bridges or dentures . Implants are surgically placed in your jawbone. Most ... other methods of replacing missing teeth, such as dentures. There are many reasons it's important to replace ...

  7. Peri-implant biomechanical responses to standard, short-wide, and mini implants supporting single crowns under axial and off-axial loading (an in vitro study).

    PubMed

    Kheiralla, Lamia Sayed; Younis, Jihan Farouk

    2014-02-01

    This study compared the biomechanical responses of 3 single crowns supported by 3 different implants under axial and off-axial loading. A standard implant (3.75 mm diameter, 13 mm length), a mini implant (3 mm diameter, 13 mm length), and a short-wide implant (5.7 mm diameter, 8 mm length) were embedded in epoxy resin by the aid of a surveyor to ensure their parallelism. Each implant supported a full metal crown made of Ni-Cr alloy with standardized dimensions. Strain gauges and finite element analysis (FEA) were used to measure the strain induced under axial and off-axial functional loads of 300 N. Results showed that mini implants recorded the highest microstrains, under both axial and off-axial loading. All implants showed a considerable increase in strain values under off-axial loading. Standard and short-wide implants proved to be preferable in supporting crowns, as the standard implant showed the lowest strains under axial and off-axial loading using FEA simulation, while the short-wide implant showed the lowest strains under nonaxial loading using strain gauge analysis. PMID:22208865

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

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

    Microsoft Academic Search

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

    2011-01-01

    l-arginine monohydrochloride monohydrate (LAHCl) single crystals have been implanted with 100keV H+ ions at different ion fluence ranging from 1012 to 1015ions\\/cm2. Implanted LAHCl single crystals have been investigated for property changes. Crystal surface and crystalline perfection of the pristine and implanted crystals were analyzed by atomic force microscope and high-resolution X-ray diffraction studies, respectively. Optical absorption bands induced by

  10. Evaluation of bone loss at single-stage and two-stage implant abutments of fixed partial dentures

    Microsoft Academic Search

    Koczorowski R; Surdacka A

    2006-01-01

    Introduction: Fixed partial dentures (FPDs) can be sup- ported on implant abutments only or on single-stage and two-stage implants and teeth. Purpose: The purpose of this study was a compara- tive analysis of bone loss at the single-stage and two-stage implant abutments of fixed partial dentures used to restore missing teeth classified as Class I or Class II according to

  11. Ion implantation induced modification of optical properties in single-crystal diamond studied by coherent acoustic phonon spectroscopy

    NASA Astrophysics Data System (ADS)

    Gregory, Justin; Steigerwald, Andrew; Takahashi, Hiroaki; Hmelo, Anthony; Tolk, Norman

    2012-10-01

    Single-crystal CVD diamond specimens were implanted with 1-MeV He+ ions at fluences ranging from 1014 to 1016 cm-2 and analyzed using coherent acoustic phonon spectroscopy. The coherent acoustic phonon response varies greatly with implantation fluence and provides depth-dependent information about the implantation defect-induced modification of diamond's optical characteristics. The results indicate an increase in the real and imaginary refractive index, as well as a sign reversal of the photoelastic coefficients at higher levels of implantation damage. These studies provide insight into the application of ion implantation to the fabrication of diamond-based photonic devices.

  12. Abstract-We investigated the implant mechanics of single tine silicon microelectrodes and conventional tungsten needle

    E-print Network

    Lübeck, Universität zu

    1 of 4 Abstract- We investigated the implant mechanics of single tine silicon microelectrodes of the main techniques to study how the brain processes information to control body functions [1]. Today (www.vsamuel.de) has developed micro-fabricated silicon arrays that one day may provide

  13. Annealing effects of helium implanted single crystals and polycrystalline magnesium aluminate spinel

    Microsoft Academic Search

    E. A. C. Neeft; A. van Veen; R. P. C. Schram; F. Labohm

    2001-01-01

    The effects of transmutation produced ?-particles and the thermal behaviour of the incorporated helium is simulated by 900 keV 3He ion implantations at 2 ?m depth in (100) surface oriented single crystals and in polycrystalline samples. Thermal Helium Desorption Spectrometry (THDS) and Neutron Depth Profiling (NDP) have been applied to study the release rate of helium and changes in the

  14. Single crystalline BaTiO3 thin films synthesized using ion implantation induced layer transfer

    NASA Astrophysics Data System (ADS)

    Park, Young-Bae; Diest, Kenneth; Atwater, Harry A.

    2007-10-01

    Layer transfer of BaTiO3 thin films onto silicon-based substrates has been investigated. Hydrogen and helium ions were co-implanted to facilitate ion-implantation-induced layer transfer of films from BaTiO3 single crystals. From thermodynamic equilibrium calculations, we suggest that the dominant species during cavity nucleation and growth are H2, H+, H2O, Ba2+ and Ba-OH, and that the addition of hydrogen to the Ba-Ti-O system can effectively suppress volatile oxide formation during layer transfer and subsequent annealing. After ion implantation, BaTiO3 layers contain microstructural defects and hydrogen precipitates in the lattice, but after layer transfer, the single crystal is found to be stoichiometric. Using direct wafer bonding and layer splitting, single crystal BaTiO3 thin films were transferred onto amorphous Si3N4 and Pt substrates. Micro-Raman spectroscopy indicated that the density of defects generated by ion implantation in BaTiO3 can be significantly reduced during post-transfer annealing, returning the transferred layer to its single crystal state. Characterization using piezoresponse force microscopy shows that the layer transferred thin films are ferroelectric, with domain structures and piezoresponse characteristics similar to that of bulk crystals.

  15. Minimally invasive HeartWare LVAD implantation through single left thoracotomy.

    PubMed

    Popov, Aron-Frederik; Mohite, Prashant Nanasaheb; Sabashnikov, Anton; Weymann, Alexander; Patil, Nikhil Prakash; Sáez, Diana García; Simon, Andre Ruediger

    2015-06-01

    Left ventricular assist device (LVAD) is now a routine therapy for advanced heart failure. Authors demonstrate a novel technique of LVAD implantation through a single left thoracotomy with anastomosis of outflow graft to the arch of aorta. The technique avoids sternotomy or additional right thoracotomy, keeps ascending aorta clear and puts outflow graft away from the sternum. PMID:25566745

  16. Single-color centers implanted in diamond nanostructures

    E-print Network

    Hausmann, Birgit J. M.

    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 ...

  17. Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

    PubMed

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2014-09-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis. PMID:25183915

  18. Cochlear implantation for single-sided deafness: the outcomes. An evidence-based approach.

    PubMed

    Vlastarakos, Petros V; Nazos, Kostas; Tavoulari, Evangelia-Filothei; Nikolopoulos, Thomas P

    2014-08-01

    The aim of the present paper is to critically review the current evidence on the efficacy of cochlear implantation as a treatment modality for single-sided deafness (SSD), and/or unilateral tinnitus. Systematic literature review in Medline and other database sources was conducted along with critical analysis of pooled data. The study selection includes prospective and retrospective comparative studies, case series and case reports. The total number of analyzed studies was 17. A total of 108 patients with SSD have been implanted; 66 patients due to problems associated with SSD, and 42 primarily because of debilitating tinnitus. Cochlear implantation in SSD leads to improved sound localization performance and speech perception in noise from the ipsilateral side with an angle of coverage up to (but not including) 90(°) to the front, when noise is present in the contralateral quartile (Strength of recommendation B). Speech and spatial hearing also subjectively improve following the insertion of a cochlear implant (Strength of recommendation B); this was not the case regarding the quality of hearing. Tinnitus improvement was also reported following implant placement (Strength of recommendation B); however, patients need to be advised that the suppression is mainly successful when the implant is activated. The overall quality of the available evidence supports a wider use of cochlear implantation in SSD following appropriate selection and counseling (overall strength of recommendation B). It remains to be seen if the long-term follow-up of large number of patients in well conducted high quality studies will confirm the above mentioned results. PMID:24096818

  19. Chick tooth induction revisited.

    PubMed

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

    2009-07-15

    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

  20. High-sensitivity temperature sensing using an implanted single nitrogen-vacancy center array in diamond

    NASA Astrophysics Data System (ADS)

    Wang, Junfeng; Feng, Fupan; Zhang, Jian; Chen, Jihong; Zheng, Zhongcheng; Guo, Liping; Zhang, Wenlong; Song, Xuerui; Guo, Guoping; Fan, Lele; Zou, Chongwen; Lou, Liren; Zhu, Wei; Wang, Guanzhong

    2015-04-01

    We presented a high-sensitivity temperature detection using an implanted single nitrogen-vacancy (NV) center array in diamond. The high-order thermal Carr-Purcell-Meiboom-Gill (TCPMG) method was performed on the implanted single NV center in diamond in a static magnetic field. We demonstrated that under small detunings for the two driving microwave frequencies, the oscillation frequency of the induced fluorescence of the NV center equals approximately the average of the detunings of the two driving fields. On the basis of the conclusion, the zero-field splitting D for the NV center and the corresponding temperature could be determined. The experiment showed that the coherence time for the high-order TCPMG was effectively extended, particularly up to 108 ? s for TCPMG-8, about 14 times the value 7.7 ? s for thermal Ramsey method. This coherence time corresponded to a thermal sensitivity of 10.1 mK/Hz1 /2. We also detected the temperature distribution on the surface of a diamond chip in three different circumstances by using the implanted NV center array with the TCPMG-3 method. The experiment implies the feasibility of using implanted NV centers in high-quality diamonds to detect temperatures in biology, chemistry, materials science, and microelectronic systems with high sensitivity and nanoscale resolution.

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

    PubMed Central

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

    2015-01-01

    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

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

    PubMed Central

    Assaf, Mohammad; Gharbyeh, Alaa’ Z. Abu

    2014-01-01

    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

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

    PubMed Central

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

    2015-01-01

    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

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

    PubMed

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

    2015-02-01

    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

  5. Magnetic and electrical characterization of TiO2 single crystals co-implanted with iron and cobalt

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    Single-crystals of TiO2 rutile were co-implanted with iron and cobalt to investigate the combined role of these ions in the magnetic properties of the system. The implantations were carried out using an energy of 150 keV and different fluences to investigate their influence in the magnetic and electrical properties of the implanted samples. For the higher fluences the as implanted single crystals exhibit superparamagnetic behaviour associated with the formation of nanosized magnetic aggregates. Annealing treatments were performed at 673 K and 1073 K, inducing recovery of the lattice structure and the evolution of the formed phases. Iron and cobalt play different roles in the implanted region, the presence of iron inhibiting the formation of cobalt aggregates during annealing at 1073 K.

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

    SciTech Connect

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

    2003-07-16

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

  7. Intracoronary stent implantation using a single high-pressure perfusion balloon catheter.

    PubMed

    Waksman, R; Shafer, C D; Seung, K B; Shen, Y; Weintraub, W S; King, S B

    1997-02-01

    Currently, the recommended strategy for Palmaz-Schatz intracoronary stent implantation is to use two balloons: an undersized balloon for predilation to facilitate a channel for the stent and a high pressure balloon for postdilation to obtain good apposition of the struts into the vessel wall. We reported our experience using the perfusion balloon as the initial balloon to dilate intracoronary lesions and demonstrated a reduction in the total number of balloons used per angioplasty procedure. The objective of this study was to examine whether a single balloon could effectively be used for stent implantation. The study population included 95 patients who underwent elective intracoronary stent placement to 100 lesions using 110 Palmaz-Schatz stents by nine individual operators. Lesions were predilated with an ACS RX LIFESTREAM balloon at a low pressure of 4-6 atm (mean 5.7 +/- 2.6). After stent deployment, the same balloon was used at a high pressure (mean 16.2 +/- 1.2). Mean balloon size, which was chosen as the stent size, was 3.4 +/- 0.4 mm. Comparison of this strategy with the recommended strategy of 68 consecutive elective stent deployments at a single center during the same time was performed. Stent implantation using a single balloon strategy was angiographically successful in 99 of 100 (99.0%) lesions. The single balloon strategy was associated with a balloon burst rate of 9.1%. The number of balloons used per stent deployment was 1.2 vs. 2.4 using the recommended strategy (P < 0.0001). There was no evidence of stent thrombosis, any MI, or target lesion revascularization during the procedure and hospitalization. One in-hospital death as a result of nonhemorrhagic stroke was documented in the treated group. We concluded that using a single high pressure perfusion balloon for pre and postdilation in patients undergoing elective stent placement is safe and reduces the number of balloons used per procedure. PMID:9047051

  8. Fracture behavior of straight or angulated zirconia implant abutments supporting anterior single crowns.

    PubMed

    Nothdurft, Frank P; Doppler, Klaus E; Erdelt, Kurt J; Knauber, Andreas W; Pospiech, Peter R

    2011-04-01

    The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments (ZirDesign™; Astra Tech, Mölndal, Sweden) supporting anterior single crowns (SCs). Four different test groups (n?=?8) representing anterior SCs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (left central incisor) from a prosthetic point of view, which allows for the use of a straight, prefabricated zirconia abutment. Groups 3 and 4 simulated a situation with a compromised implant position, requiring an angulated (20°) abutment. OsseoSpeed™ implants (Astra Tech) 4.5 mm in diameter and 13 mm in length were used to support the abutments. The SCs (chromium cobalt alloy) were cemented with glass ionomer cement. Groups 2 and 4 were thermomechanically loaded (TCML?= 1.2 × 10?; 10,000 × 5°/55°) and subjected to static loading until failure. Statistical analysis of force data at the fracture site was performed using nonparametric tests. All samples tested survived TCML. Artificial aging did not lead to a significant decrease in load-bearing capacity in either the groups with straight abutments or the groups with angulated abutments. The restorations that utilized angulated abutments exhibited higher fracture loads than the restorations with straight abutments (group 1, 280.25 ± 30.45 N; group 2, 268.88 ± 38.00 N; group 3, 355.00 ± 24.71 N; group 4, 320.71 ± 78.08 N). This difference in load-bearing performance between straight and angulated abutments was statistically significant (p = 0.000) only when no artificial aging was employed. The vast majority of the abutments fractured below the implant shoulder. PMID:20084415

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

    PubMed Central

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

    2014-01-01

    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

  10. How a Tooth Decays

    MedlinePLUS

    Illustrations: How a Tooth Decays 1. Healthy Tooth 2. White Spots Enamel is the hard outer crystal- ... the gum) can form in the soft tissues. Illustrations created by Simple Steps designer Lynda Buchhalter More ...

  11. 3D Statistical Models for Tooth Surface Reconstruction

    E-print Network

    Boyer, Edmond

    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

  12. Study of the negative magneto-resistance of single proton-implanted lithium-doped ZnO microwires

    NASA Astrophysics Data System (ADS)

    Lorite, I.; Zandalazini, C.; Esquinazi, P.; Spemann, D.; Friedländer, S.; Pöppl, A.; Michalsky, T.; Grundmann, M.; Vogt, J.; Meijer, J.; Heluani, S. P.; Ohldag, H.; Adeagbo, W. A.; Nayak, S. K.; Hergert, W.; Ernst, A.; Hoffmann, M.

    2015-06-01

    The magneto-transport properties of single proton-implanted ZnO and of Li(7%)-doped ZnO microwires have been studied. The as-grown microwires were highly insulating and not magnetic. After proton implantation the Li(7%) doped ZnO microwires showed a non-monotonous behavior of the negative magneto-resistance (MR) at temperature above 150 K. This is in contrast to the monotonous NMR observed below 50 K for proton-implanted ZnO. The observed difference in the transport properties of the wires is related to the amount of stable Zn vacancies created at the near surface region by the proton implantation and Li doping. The magnetic field dependence of the resistance might be explained by the formation of a magnetic/non-magnetic heterostructure in the wire after proton implantation.

  13. Effect of ion fluence on the surface morphology of single crystal magnesium oxide implanted with xenon

    SciTech Connect

    Jiang, W.; Norton, M.G. [Department of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 (United States); Poker, D.B. [Surface Modification and Characterization Research Facility, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    1995-11-01

    The surface morphology of (001)-oriented single crystal magnesium oxide (MgO) implanted with xenon ions has been examined using atomic force microscopy. It was found that at the lowest fluence used in this study (1.0{times}10{sup 14}/cm{sup 2}), slight roughening of the (001) surface occurred. The magnitude of this roughening remained fairly constant with increases in fluence in the range 1.0{times}10{sup 14}/cm{sup 2} to 3.0{times}10{sup 16}/cm{sup 2}. Implantation at fluences of {ge}1.0{times}10{sup 17}/cm{sup 2} caused significant surface roughening with the concomitant formation of micro-sized blisters. The appearance of some of these blisters resembles the rosette pattern which is also observed when the cleaved surfaces of MgO crystals are etched following indentation using a spherical indenter. This observation suggests that these blisters are formed by the growth of xenon inclusions, during implantation, by a dislocation loop punching mechanism. {copyright} 1995 {ital Materials} {ital Research} {ital Society}.

  14. Implantation of HeartMate II Left Ventricular Assist Device in a Single-Lung Patient.

    PubMed

    Copeland, Hannah; Stoletniy, Liset; Sakr, Antoine; Razzouk, Anees

    2015-06-01

    The use of mechanical assist devices has been established as an effective therapy for patients with end-stage heart failure. Implantable left ventricular assist devices are becoming more common in the clinical practice of cardiac surgery. This report illustrates the use of a HeartMate II (Thoratec Pleasanton, CA) left ventricular assist device in a patient with a single lung and dilated cardiomyopathy. To our knowledge, this is the first report of a left ventricular assist device placement in a patient with a prior pneumonectomy. PMID:26046884

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

    PubMed Central

    Rutherglen, Christopher

    2009-01-01

    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

  16. Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study.

    PubMed

    Lee, Cameron Y; Wong, Natalie; Ganz, Scott D; Mursic, Jonathan; Suzuki, Jon B

    2014-06-26

    Abstract The accuracy of a digital impression technique to fabricate the implant restoration and abutment for a dental implant using an intraoral scanner was evaluated in 36 patients missing a single posterior tooth in the mandible or maxilla restored with a single implant. Data from the scanning protocol was delivered via the Internet in the form of a standard triangulation language file to the manufacturing site for the production of a custom computer-aided design abutment and crown. All 36 restorations were evaluated for marginal integrity, interproximal contact points, and occlusion. Six of the 36 patients required contact adjustment, 7 required occlusal adjustment and 3 required a gingivectomy around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15 minutes. Conclusion: An intraoroal laser scanner can be used with confidence to obtain consistent accurate digital impressions to fabricate custom restorations and abutments for dental implants. PMID:24967654

  17. 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

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

    2014-01-01

    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

  18. Tooth autotransplantation: an overview and case study.

    PubMed

    Schmidt, Samuel K; Cleverly, David G

    2014-08-01

    It is not uncommon for children or young adults to have congenitally missing teeth or early loss of teeth from trauma or caries. The restorative options are typically bridges, implants, and removable appliances. Often overlooked and misunderstood, another treatment option exists in autotransplantation, where a tooth is moved from one site to another in the same individual. Autotransplantation is well studied and has predictable results comparable to implants, with reported success rates often greater than 90%. This article will provide an overview of autotransplantation, its indications, advantages, complications, and treatment considerations, along with a case of a third molar autotransplant that will serve to highlight these points. PMID:25226677

  19. Tooth autotransplantation: an overview and case study.

    PubMed

    Schmidt, Samuel K; Cleverly, David G

    2012-01-01

    It is not uncommon for children or young adults to have congenitally missing teeth or early loss of teeth from trauma or caries. The restorative options are typically bridges, implants, and removable appliances. Often overlooked and misunderstood, another treatment option exists in autotransplantation, where a tooth is moved from one site to another in the same individual. Autotransplantation is well studied and has predictable results comparable to implants, with reported success rates often greater than 90%. This article will provide an overview of autotransplantation plantation, its indications, advantages, complications, and treatment considerations, along with a case of a third molar autotransplant that will serve to highlight these points. PMID:22928465

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

    PubMed

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

    2003-08-01

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

  1. Methods for implantation of micro-wire bundles and optimization of single/multiunit recordings from human mesial temporal lobe

    PubMed Central

    Misra, A; Burke, JF; Ramayya, A; Jacobs, J; Sperling, MR; Moxon, KA; Kahana, MJ; Evans, JJ; Sharan, AD

    2014-01-01

    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 Result 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. PMID:24608589

  2. Comparison of marginal bone loss and patient satisfaction in single and double-implant assisted mandibular overdenture by immediate loading

    PubMed Central

    Khoshhal, Masume; Ebrahimzadeh, Zahra

    2015-01-01

    PURPOSE The purpose of this study was to compare the coronal bone level and patient satisfaction in 1-implant and 2-implant assisted mandibular overdentures. MATERIALS AND METHODS Twenty patients who had maladaptive mandibular dentures were treated in this study. Patients were randomly divided into two groups. The first group received 1 implant (Simple line II, Implantium, South Korea) in their mandibular midline and the second group received 2 implants in their B and D regions (according to Misch's category). If the primary stability of each implant was at least 60 ISQ, ball attachment was placed and denture relined with soft liner. After 6 weeks, retentive cap incorporated with hard acrylic resin. In the 6 and 12 months recalls, periapical digital radiograph were made and visual analogue scale questionnaires were used to record patient satisfaction. The Friedman test was done for comparing the presurgical and postsurgical parameters in each group and the U-Mann Whitney test (P<.05) was done for comparison of post-treatment results between the two groups. RESULTS All implants achieved sufficient primary stability to be immediately loaded. Patient satisfaction was high, and there were no significant differences between two groups (P>.05). In addition, mean marginal bone loss was 0.6 ± 0.67 mm in the first group and 0.6 ± 0.51 mm in the second group, after 12 month. Mean marginal bone loss showed no significant differences between two groups. CONCLUSION This preliminary one-year result indicated that mandibular overdentures anchored to a single implant can be a safe and cost-effective method as a starting step for implant-overdenture treatment.

  3. Upper Arm Central Venous Port Implantation: A 6-Year Single Institutional Retrospective Analysis and Pictorial Essay of Procedures for Insertion

    PubMed Central

    Shiono, Masatoshi; Takahashi, Shin; Kakudo, Yuichi; Takahashi, Masanobu; Shimodaira, Hideki; Kato, Shunsuke; Ishioka, Chikashi

    2014-01-01

    Background The requirement of central venous (CV) port implantation is increasing with the increase in the number of cancer patients and advancement in chemotherapy. In our division, medical oncologists have implanted all CV ports to save time and consultation costs to other departments. Recently, upper arm implantation has become the first choice as a safe and comfortable method in our unit. Here we report our experience and discuss the procedure and its potential advantages. Methods All CV port implantations (n?=?599) performed in our unit from January 2006 to December 2011 were analyzed. Procedural success and complication rates between subclavian and upper arm groups were compared. Results Both groups had similar patient characteristics. Upper arm CV port and subclavian implantations were equivalently successful and safe. Although we only retrospectively analyzed data from a single center, the upper arm group had a significantly lower overall postprocedural complication rate than the subclavian group. No pneumothorax risk, less risk of arterial puncture by ultrasound, feasibility of stopping potential arterial bleeding, and prevention of accidental arterial cannulation by targeting the characteristic solitary basilic vein were the identified advantages of upper arm CV port implantation. In addition to the aforementioned advantages, there is no risk of “pinch-off syndrome,” possibly less patient fear of manipulation, no scars on the neck and chest, easier accessibility, and compatibility with the “peripherally inserted central catheter” technique. Conclusions Upper arm implantation may benefit clinicians and patients with respect to safety and comfort. We also introduce our methods for upper arm CV port implantation with the videos. PMID:24614412

  4. Current approaches and challenges in making a bio-tooth.

    PubMed

    Yu, Jinhua; Shi, Junnan; Jin, Yan

    2008-09-01

    Tooth loss adversely affects not only mouth functions but also the esthetics of one's face. To repair these defects, current treatment methods mainly depend on nonbiological materials or artificial implants that also can, sometimes, reduce the quality of life because of their limited physiological function, or elicit an immunological rejection. Theoretically, a biological tooth (bio-tooth) that is made from the patient's own cells and grows in its intended location should be the best choice for treating tooth loss, although such bioengineered teeth have been nothing more than a dream for many centuries. Recently, significant advances in the fields of tissue engineering, stem cell biology, developmental biology, molecular genetics, and bionics have brought us close to the realization of a bio-tooth. However, issues involving in the reconstruction of a bio-tooth regarding the shape determination, size control, availability of dental epithelium, directional growth and eruption, and graft rejection in the jaws remain to be resolved. Here, this review outlines the current approaches toward the tooth regeneration, and focuses on several key challenges that must be met in the making of a bio-tooth. PMID:18665759

  5. Simplified type 3 implant placement, after alveolar ridge preservation: a case study

    PubMed Central

    CECCHETTI, F.; GERMANO, F.; BARTULI, F.N.; ARCURI, L.; SPUNTARELLI, M.

    2014-01-01

    Alveolar ridge, after tooth extraction, could reduce its volume up to 50% in buccal-lingual width in the first twelve months and residual dimensions could interfere with correct three dimensional placement of implants and influence negatively treatment outcomes with regard to function and aesthetic aspects. Over the last decades, several approaches have been proposed and tested in order to prevent ridge volumetric contraction and provide maximum bone availability for implant procedure. This article presents a case study with a single anterior tooth replacement, illustrating socket seal technique followed by a type 3 timing implant placement. Immediately after tooth extraction, residual socket was grafted using Deproteinized Bovine Bone Mineral and a free gingival punch harvested from palate. After 3 months, a root-form titanium implant was inserted without additional regenerative procedures. Follow-up examination revealed favourable preservation of soft tissue width and height in the aesthetic area. Socket seal approach maximizes soft tissue healing, preserving ridge envelope and the subsequent implant placement, furthermore, results simplified, as any augmentation techniques are required. Clinical advantages of this method include predictable preservation of the soft tissues, favourable healing features, easy handling of graft materials and a positive benefit-cost ratio. PMID:25992262

  6. Strain Doping: Reversible Single-Axis Control of a Complex Oxide Lattice via Helium Implantation

    NASA Astrophysics Data System (ADS)

    Guo, Hangwen; Dong, Shuai; Rack, Philip D.; Budai, John D.; Beekman, Christianne; Gai, Zheng; Siemons, Wolter; Gonzalez, C. M.; Timilsina, R.; Wong, Anthony T.; Herklotz, Andreas; Snijders, Paul C.; Dagotto, Elbio; Ward, Thomas Z.

    2015-06-01

    We report on the use of helium ion implantation to independently control the out-of-plane lattice constant in epitaxial La0.7Sr0.3MnO3 thin films without changing the in-plane lattice constants. The process is reversible by a vacuum anneal. Resistance and magnetization measurements show that even a small increase in the out-of-plane lattice constant of less than 1% can shift the metal-insulator transition and Curie temperatures by more than 1 0 0 °C . Unlike conventional epitaxy-based strain tuning methods which are constrained not only by the Poisson effect but by the limited set of available substrates, the present study shows that strain can be independently and continuously controlled along a single axis. This permits novel control over orbital populations through Jahn-Teller effects, as shown by Monte Carlo simulations on a double-exchange model. The ability to reversibly control a single lattice parameter substantially broadens the phase space for experimental exploration of predictive models and leads to new possibilities for control over materials' functional properties.

  7. DEALING WITH DENTAL IMPLANT FAILURES

    PubMed Central

    Levin, Liran

    2008-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  9. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    PubMed Central

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

    2013-01-01

    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

  10. Charcot-Marie-Tooth Disease

    MedlinePLUS

    NINDS Charcot-Marie-Tooth Disease Information Page Condensed from Charcot-Marie-Tooth Disease Fact Sheet Table of Contents (click ... Trials Organizations Additional resources from MedlinePlus What is Charcot-Marie-Tooth Disease? Charcot-Marie-Tooth disease (CMT) ...

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

    SciTech Connect

    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

    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.

  12. Tooth - abnormal colors

    MedlinePLUS

    ... of tooth development can cause changes in the color and hardness of the enamel. ... temporarily stain the teeth, such as tea or coffee Genetic ... overuse of fluoride rinses, toothpaste, and fluoride supplements

  13. Tooth decay - early childhood

    MedlinePLUS

    Bottle mouth; Bottle carries; Baby bottle tooth decay; Early childhood caries (ECC) ... health. Am Fam Physician . 2004;70:2113-2120. Dental caries. In: Kliegman RM, Behrman RE, Jenson HB, Stanton ...

  14. Allogenous tooth fragment reattachment

    PubMed Central

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

    2013-01-01

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

  15. Evaluation of implants placed immediately or delayed into extraction sites

    PubMed Central

    Pal, U. S.; Dhiman, Neeraj Kumar; Singh, Geeta; Singh, R. K.; Mohammad, Shadab; Malkunje, Laxman R.

    2011-01-01

    Aims and objectives: To compare the success rate of implant placed immediately in extraction socket vs implant placed delayed in extraction socket. Materials and Methods: The study comprised of 8 patients (6 male and 2 female, aged from 14 to 58 year) for evaluation of implant placement immediately (i.e. Group – A) or delayed (i.e. Group – B) into extraction site, in which at 12 sites implants were placed. Results: The inclusion criteria for implantation was tooth/teeth with one or two degree mobility, root stumps, tooth with failure root canal treatment and extraction sockets. HI-TEC TRX-OP (Life Care) with abutment, non-submerged, tapered at apical 5 mm, sand-blasted & acid etched surfaced implants were used. These are one stage single implants made of commercially pure titanium. The length of implants used was 10 mm and 13 mm and diameter was 3.70 mm and 4.50 mm. The vertical bone dimension was determined by palpation and radiograph (intra-oral periapical, orthopantomograph and dentascan in some patients). Gingival condition, bone condition was examined clinically and radiographically. Discussion: Post-operative evaluation was done under clinical parameters (i.e. Pain (VAS), Swelling, Stability (By Glickman method), Gingival status, Probing depth (By Williams Periodontal probe), Patient's compliance / satisfaction, Complications (If any) and Radiological parameters was (Intra-oral periapical radiograph, orthopantomograph, Dentascan). Conclusion: Overall conclusion drawn from this study was that both the groups are showing similar results but Group-A is slightly better than Group-B PMID:22442611

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

    PubMed

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

    2012-06-01

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

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

    Microsoft Academic Search

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

    2007-01-01

    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

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

    PubMed Central

    2014-01-01

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

  19. Single-Dose Local Simvastatin Injection Improves Implant Fixation via Increased Angiogenesis and Bone Formation in an Ovariectomized Rat Model

    PubMed Central

    Tan, Jie; Yang, Ning; Fu, Xin; Cui, Yueyi; Guo, Qi; Ma, Teng; Yin, Xiaoxue; Leng, Huijie; Song, Chunli

    2015-01-01

    Background Statins have been reported to promote bone formation. However, taken orally, their bioavailability is low to the bones. Implant therapies require a local repair response, topical application of osteoinductive agents, or biomaterials that promote implant fixation. Material/Methods The present study evaluated the effect of a single local injection of simvastatin on screw fixation in an ovariectomized rat model of osteoporosis. Results Dual-energy X-ray absorptiometry, micro-computed tomography, histology, and biomechanical tests revealed that 5 and 10 mg simvastatin significantly improved bone mineral density by 18.2% and 22.4%, respectively (P<0.05); increased bone volume fraction by 51.0% and 57.9%, trabecular thickness by 16.4% and 18.9%, trabeculae number by 112.0% and 107.1%, and percentage of osseointegration by 115.7% and 126.3%; and decreased trabeculae separation by 34.1% and 36.6%, respectively (all P<0.01). Bone mineral apposition rate was significantly increased (P<0.01). Furthermore, implant fixation was significantly increased (P<0.05), and bone morphogenetic protein 2 (BMP2) expression was markedly increased. Local injection of a single dose of simvastatin also promoted angiogenesis. Vessel number, volume, thickness, surface area, and vascular volume per tissue volume were significantly increased (all P<0.01). Vascular endothelial growth factor (VEGF), VEGF receptor-2, von Willebrand factor, and platelet endothelial cell adhesion molecule-1 expression were enhanced. Conclusions A single local injection of simvastatin significantly increased bone formation, promoted osseointegration, and enhanced implant fixation in ovariectomized rats. The underlying mechanism appears to involve enhanced BMP2 expression and angiogenesis in the target bone. PMID:25982481

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

    PubMed Central

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

    2013-01-01

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

  1. Ask a Periodontist (Frequently Asked Questions about Gum Disease)

    MedlinePLUS

    ... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

  2. Periodontal Disease and Systemic Health

    MedlinePLUS

    ... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

  3. Gum Disease Symptoms

    MedlinePLUS

    ... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

  4. Gum Disease and Women

    MedlinePLUS

    ... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

  5. Microbiota around teeth and dental implants in periodontally healthy, partially edentulous patients: is pre-implant microbiological testing relevant?

    PubMed

    Meijndert, Leo; van der Reijden, Wil A; Raghoebar, Gerry M; Meijer, Henny J A; Vissink, Arjan

    2010-08-01

    This study aimed to assess the prevalence of seven periodontal marker pathogens, before implant placement and 1 yr after loading, in periodontally healthy individuals and to assess the long-term effectiveness of pre-implant reduction of pathogens to below threshold levels. In 93 individuals needing single tooth replacement, pooled subgingival microbiological samples from standard sites were cultured and analyzed before implant treatment and 1 yr after loading. Threshold levels commonly used in periodontology to predict periodontal breakdown were applied. Subjects with levels of pathogens above these thresholds received initial periodontal treatment including systemic antibiotics when indicated. At baseline, 49.5% of periodontally healthy subjects harboured one or more marker pathogens above threshold levels. Periodontal treatment reduced the pathogen levels below threshold values in 78.3% of these initially colonized subjects. In all cases Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were reduced to below threshold. At 1 yr after loading, periodontal pathogens were present above threshold levels in 74.1% of all subjects. It is concluded that in almost half of periodontal healthy individuals the subgingival biofilm harbours periodontal pathogens above threshold values. Long-term effectiveness of pre-implant reduction of the selected marker pathogens appeared limited in our patient population, making pre-implant reduction unpredictive for post-implant levels of these pathogens. Thus, considering the applied microbiological criteria, generalized pre-implant microbiological testing is not contributory in periodontally healthy subjects. PMID:20662908

  6. What Are Tooth Preservation Kits?

    MedlinePLUS

    ... Aid: What to Do Pregnant? What to Expect Sports: Keeping Kids Safe Concussions: What to Know What Are Tooth Preservation Kits? KidsHealth > Parents > Sports Medicine Center > Q&As > What Are Tooth Preservation ...

  7. Broken or knocked out tooth

    MedlinePLUS

    Teeth - broken; Tooth - knocked out ... A permanent tooth that is knocked out can sometimes be put back in place. In most cases, only permanent, adult teeth are reimplanted into the mouth. Baby teeth are ...

  8. Charcot-Marie-Tooth disease

    MedlinePLUS

    Charcot-Marie-Tooth disease is a group of disorders passed down through families that affect the nerves ... Charcot-Marie-Tooth is one of the most common nerve-related disorders passed down through families (inherited). ...

  9. The Rachitic Tooth

    PubMed Central

    Nociti, Francisco H.; Somerman, Martha J.

    2014-01-01

    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

  10. The study of structural properties of 100 keV hydrogen ion implanted semi-insulating GaAs single crystals

    Microsoft Academic Search

    M. Udhayasankar; J. Kumar; P. Ramasamy; K. Sekar; B. Sundaravel; C. Ferrari; L. Lazzarini; P. Magudapathy; K. G. M Nair

    1999-01-01

    100 keV hydrogen ion implantation has been carried out on undoped semi-insulating ?100? gallium arsenide single crystals for various ion doses at room temperature. The structural properties due to high dose, low energy hydrogen ion implantation has been investigated using X-ray double crystal diffractometry (DCD) analysis, Rutherford backscattering spectrometry and channeling (RBS\\/C) experiments and transmission electron microscopy (TEM) analysis. By

  11. Gear tooth topological modification

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  12. TEM AND RBS STUDIES OF SINGLE AND DOUBLE DISCRETE BURIED DAMAGE LAYERS IN P+ IMPLANTED Si ON SUBSEQUENT LASER ANNEALING

    SciTech Connect

    Sadana, D.K.; Strathman, M.; Washburn, J.; Booker, G.R.

    1980-01-01

    This work is aimed at studying the regrowth behaviour of single and double buried damage layers on subsequent laser annealing of P{sup +) implanted Si, implanted at 120 keV to doses of 5 x 10{sup 14}/cm{sup 2} and 7.5 x10{sup 15}/cm{sup 2}, respectively. A Q-switched ruby laser operating at a wavelength of 0.695{micro}m was used for the annealing. 90{degrees} cross sectional TEM and MeV He{sup +} channelling spectroscopy were used to examine the damage structures and their depth distributions. At 0.9 J/cm{sup 2}, TEM results showed that the single buried damage layer regrew into two discrete damage layers. At 2.0 J/cm{sup 2}, TEM results showed that the first layer in the double buried damage layers type structures either completely annealout out, leaving a partially annealed second layer consisting of damage clusters or had dislocations in the first damage layer region that extended from the surface and were in direct contact with the deeper lying second layer of damage clusters. The MeV He{sup +} channelling spectra for the above samples were in agreement with the TEM results.

  13. Pulsed laser deposition of bioceramic thin films from human tooth

    NASA Astrophysics Data System (ADS)

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

    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 12 J/cm2, respectively. Layers were deposited onto heated (250 °C) titanium, glass, and KBr substrates. The increase of the pellet pressing pressure from 150 to 450 MPa enhanced the roughness of the deposited films. IR spectroscopic measurements showed that the chemical composition of the films were close to that of original tooth material under appropriate fluence. The adherence of the layers to the substrates could be significantly improved by post annealing at 550 °C.

  14. Restorative Factors That Affect the Biomechanics of the Dental Implant

    Microsoft Academic Search

    Linish Vidyasagar; Peteris Apse

    2003-01-01

    SUMMARY Dental implants have become a significant aspect of tooth replacement in prosthodontic treatment. Despite of high success rates, complications and failures still occur. One factor that is increasingly being implicated with dental implant failure is occlusal overloading. Overloading of dental implants during functional and parafunctional activity has been extensively discussed from an empirical point of view but with sparse

  15. Two stage gear tooth dynamics program

    NASA Technical Reports Server (NTRS)

    Boyd, Linda S.

    1989-01-01

    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.

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

    PubMed

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

    2006-02-01

    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

  17. Healing of a Cyst-like Lesion Involving an Implant with Nonsurgical Management.

    PubMed

    Kahler, Bill

    2015-05-01

    Numerous reports primarily in the implant literature outline the loss of an implant claimed to be as a consequence of endodontic pathosis from an adjacent tooth. This case report outlines the resolution of a large cyst-like periapical lesion that resolved with nonsurgical management when the canal was dressed with calcium hydroxide on 4 occasions because of persistent intracanal exudate. A favorable healing outcome was achieved for the affected tooth and the implant. This report adds to a growing body of evidence to suggest that implant retained crowns are not vulnerable when an endodontic infection occurs in an adjacent tooth. PMID:25649297

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

    SciTech Connect

    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

    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.

  19. Low-energy model for ion implantation of arsenic and boron into (100) single-crystal silicon

    Microsoft Academic Search

    Borna J. Obradovic; Steven J. Morris; Michael F. Morris; Shiyang Tian; Geng Wang; K. Beardmore; C. Snell; J. Jackson; S. Baummann; Al F. Tasch

    1997-01-01

    It has been recently observed that ion implantation simulators based on the binary collision approximation (BCA) are not as accurate for low energy implants (less than 5 keV), despite their success at higher energies. The accuracy of molecular dynamics based simulators on the other hand, is independent of the implantation energy, but the computation times are extremely long. This work

  20. Synthesis of CAD\\/CAM, robotics and biomaterial implant fabrication: single-step reconstruction in computer aided frontotemporal bone resection

    Microsoft Academic Search

    Stephan Weihe; Michael Wehmöller; Henning Schliephake; Stefan Haßfeld; Alexander Tschakaloff; Jörg Raczkowsky; Harald Eufinger

    2000-01-01

    The preoperative manufacturing of individual skull implants, developed by an interdisciplinary research group at Ruhr-University Bochum, is based on the use of titanium as the most common material for implants at present. Using the existing technology for materials that can be milled or moulded, customized implants may be manufactured as well. The goal of the study was to examine biodegradable

  1. Cochlear Implants

    MedlinePLUS

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

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

    PubMed

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

    2013-01-01

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

  3. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    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.

  4. Role of multiple cusps in tooth fracture.

    PubMed

    Barani, Amir; Bush, Mark B; Lawn, Brian R

    2014-07-01

    The role of multiple cusps in the biomechanics of human molar tooth fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal fractures with number of cuspal contacts, indicating a capacity for an individual tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces. PMID:24755003

  5. Cost-effectiveness of anterior implants versus fixed dental prostheses.

    PubMed

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

    2013-12-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  7. New Perspectives on Tooth Wear

    PubMed Central

    Lucas, Peter W.; Omar, Ridwaan

    2012-01-01

    Some of the efforts that have been made to document tooth wear are reviewed here with an emphasis on nonhuman mammals, literature with which dentists may not be very familiar. We project a change in research strategy from the description of wear at various scales of measurement towards investigation of the mechanical mechanisms that actually create the texture of a worn surface. These studies should reveal exactly how tooth tissue is lost and what aspects of the structure of dental tissues affect this. The most important aspects of the interaction between the tooth surface and wear particles would appear to be particle size, particle shape, their mechanical properties with respect to those of tooth tissues, and the influence of saliva. PMID:22536239

  8. Sinus augmentation at the time of molar tooth removal: modification of jensen technique.

    PubMed

    Block, Michael S

    2015-06-01

    When a maxillary molar tooth needs to be removed, the treatment plan often includes subsequent dental implant placement. However, there may be less than 5 mm of bone available in the central fossa region of the proposed implant site. This report describes a technique to use a precise osteotomy within the maxillary molar socket to mobilize a segment of bone and superiorly raise it to provide increased alveolar bone height using grafting. This technique eliminates the need for lateral window surgery. PMID:25659359

  9. The Early Years: Tooth Time

    NSDL National Science Digital Library

    Peggy Ashbrook

    2006-03-01

    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.

  10. Effect of Platelet Rich Fibrin (PRF) on Peri-implant Soft Tissue and Crestal Bone in One-Stage Implant Placement: A Randomized Controlled Trial

    PubMed Central

    Boora, Priyanka; Bhoria, Mohaneesh

    2015-01-01

    Introduction The viability of Platelet Rich Fibrin (PRF) on enhancement of osseous and associated tissue healing has been substantiated well in literature. However, paucity in the applicability of PRF to enhance peri-implant healing in oral region is not well-corroborated. Purpose This prospective study evaluated the effect of Platelet PRF on peri-implant tissue response following one-stage implant placement with non-functional immediate provisionalization in maxillary anterior region. Materials and Methods A Prospective, Randomized Controlled Trial (RCT) was conducted across 20 (15 male, 5 Female) systemically healthy subjects with maintainable oral hygiene. Subjects were broadly divided into two groups i.e. Study group (PRF group) and Control group (Non-PRF group). Twenty standard SLA- AB/AE (alumina oxide blasted/acid etched surface treated) tapered threaded dental implants were randomly placed with and without PRF and immediately provisionalized. The subjects were evaluated clinically and radiographically at baseline (at time of implant placement), one month and three month post-operatively for peri-implant soft tissue and crestal bone responses. Results At 3 months, all implants remained osseointegrated. The mean marginal bone changes were observed from baseline to 3 months in both groups with lesser changes observed in PRF Group. No significant differences in probing depth and bleeding on probing were noted during follow-up. Conclusion Within the limitations of this study, PRF could be considered as a healing biomaterial with potential beneficial effect on peri-implant tissue and can be used as a therapeutic adjuvant in clinical scenario of one stage, single tooth implant placement procedure in maxillary anterior region. PMID:26023636

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

    PubMed Central

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

    2010-01-01

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

  12. Temporary Anchorage Devices for Tooth Movement: A Review and Case Reports

    Microsoft Academic Search

    Michael K. McGuire; E. Todd Scheyer; Ronald L. Gallerano

    2006-01-01

    Background: Temporary anchorage devices (TADs) are immediately loaded miniscrew and osseointegrated palatal implants that are placed to control tooth movement during orthodontic treatment and removed when the treatment is completed. They are a relatively new addition to the dental ar- mamentarium and can be used in some cases to replace tradi- tional orthodontic extraoral appliances. Because placement requires a surgical

  13. Cochlear Implants

    MedlinePLUS

    ... and Medical Procedures Implants and Prosthetics Cochlear Implants Cochlear Implants View movie of the normal ear, ear with hearing loss, and cochlear implant procedure (Requires Flash Player - Download now ) Welcome to ...

  14. Dental Implants

    MedlinePLUS

    Dental Implants A fuller, more complete smile is within reach. The following information is designed to provide helpful ... whether dental implants are right for your situation. Dental Implants and Roots The key benefit of dental implants ...

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

    PubMed Central

    Kajale, Aniruddha M.; Mehta, Dhoom S.

    2014-01-01

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

  16. Clinical measurement of tooth wear: Tooth wear indices

    PubMed Central

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

    2012-01-01

    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

  17. 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

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

    2015-01-01

    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

  18. BRIEF COMMUNICATIONS: Use of argon laser radiation in restoration of single-crystal state of ion-implantation-amorphized silicon surface

    Microsoft Academic Search

    A. G. Klimenko; É. A. Klimenko; Valerii I. Donin

    1975-01-01

    High-power (up to 500 W) radiation of a cw argon laser was used to restore the single-crystal state of a silicon surface made amorphous by ion implantation. The experiments were carried out in air and the power density of the laser radiation was 100 W\\/cm2. The duration of illumination did not exceed several seconds. The experiments were carried out on

  19. Improving purity and size of single-crystal diamond plates produced by high-rate CVD growth and lift-off process using ion implantation

    Microsoft Academic Search

    Y. Mokuno; A. Chayahara; H. Yamada; N. Tsubouchi

    2009-01-01

    The lift-off process using ion implantation has recently been applied to produce large and thick single-crystal diamond plates by chemical vapor deposition (CVD). CVD growth conditions for undoped, as opposed to nitrogen-doped, diamond were investigated to improve the purity of plates produced by this technique. This utilized apparatus identical to that for high-rate growth with nitrogen addition under high-density plasma.

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

    PubMed

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

    2013-01-01

    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

  1. An overview of U.S. predoctoral dental implant programs and their directors.

    PubMed

    Barwacz, Christopher A; Avila-Ortiz, Gustavo; Allareddy, Veerasathpurush; Tamegnon, Monelle; Hoogeveen, Kaitlin

    2015-03-01

    The aim of this study was to provide an overview of current predoctoral implant programs in the United States, including curricular characteristics and clinical practices regarding implant therapy education and program directors' characteristics. An electronic survey was sent to predoctoral implant program directors of all 64 accredited U.S. dental schools; 52 of the 60 eligible programs responded, for a response rate of 87%. The responding program directors were primarily affiliated with either prosthodontics departments (44%) or restorative dentistry departments (40%). Structurally, 80.8% of the responding schools integrate their implant programs into the third year of the curriculum. Clinical implant therapy exercises reported were simulation exercises without direct patient care (90.4% of responding schools) and direct patient care under supervision (94.2%). The most frequently taught restorative modalities are posterior single-tooth implant crown (96.2%), mandibular implant-retained overdenture (88.5%), and anterior implant-supported single crown (61.5%). A majority (74.5%) of responding programs utilize analog surgical guide planning, while 25.5% reported use of digital guided surgery planning software. All schools in the Northwest and 66.7% in the South Central regions utilize custom abutments as the primary abutment design, while a majority of schools in the North Central (62.5%), Northeast (53.8%), Southwest (66.7%), and Southeast (80%) regions use stock abutments (p=0.02). Regional differences were significant with regard to fixation modality, with all the Northwest programs using screw retention and 90% of Southeast and 87.5% of North Central programs using cement retention (p=0.002). This study demonstrated that while institutions share program director and curricular similarities, clinical practices and modalities vary significantly by region. PMID:25729020

  2. Detecting Gear Tooth Fatigue Cracks in Advance of Complete Fracture

    NASA Technical Reports Server (NTRS)

    Zakrajsek, James J.; Lewicki, David G.

    1996-01-01

    Results of using vibration-based methods to detect gear tooth fatigue cracks are presented. An experimental test rig was used to fail a number of spur gear specimens through bending fatigue. The gear tooth fatigue crack in each test was initiated through a small notch in the fillet area of a tooth on the gear. The primary purpose of these tests was to verify analytical predictions of fatigue crack propagation direction and rate as a function of gear rim thickness. The vibration signal from a total of three tests was monitored and recorded for gear fault detection research. The damage consisted of complete rim fracture on the two thin rim gears and single tooth fracture on the standard full rim test gear. Vibration-based fault detection methods were applied to the vibration signal both on-line and after the tests were completed. The objectives of this effort were to identify methods capable of detecting the fatigue crack and to determine how far in advance of total failure positive detection was given. Results show that the fault detection methods failed to respond to the fatigue crack prior to complete rim fracture in the thin rim gear tests. In the standard full rim gear test all of the methods responded to the fatigue crack in advance of tooth fracture; however, only three of the methods responded to the fatigue crack in the early stages of crack propagation.

  3. Molecular Genetics of Tooth Development

    PubMed Central

    Bei, Marianna

    2009-01-01

    Organogenesis depends upon a well-ordered series of inductive events involving coordination of molecular pathways that regulate the generation and patterning of specific cell types. Key questions in organogenesis involve the identification of the molecular mechanisms by which proteins interact to organize distinct pattern formation and cell fate determination. Tooth development is an excellent context for investigating this complex problem because of the wealth of information emerging from studies of model organisms and human mutations. Since there are no obvious sources of stem cells in adult human teeth, any attempt to create teeth de novo will likely require the re-programming of other cell types. Thus, the fundamental understanding of the control mechanisms responsible for normal tooth patterning in the embryo will help us understand cell fate specificity and may provide valuable information towards tooth organ regeneration. PMID:19875280

  4. Tooth Disorders - Multiple Languages: MedlinePlus

    MedlinePLUS

    ... Are Here: Home ? Multiple Languages ? All Health Topics ? Tooth Disorders URL of this page: http://www.nlm.nih. ... V W XYZ List of All Topics All Tooth Disorders - Multiple Languages To use the sharing features on ...

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

    NASA Astrophysics Data System (ADS)

    Komitopoulos, Nikolaos; Vakouftsis, Christos

    2014-10-01

    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.

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

    PubMed Central

    Jain, Anoop; Sumra, Nida

    2015-01-01

    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

  7. Tooth Avulsion in the School Setting

    ERIC Educational Resources Information Center

    Krause-Parello, Cheryl A.

    2005-01-01

    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…

  8. Cochlear Implants.

    ERIC Educational Resources Information Center

    Clark, Catherine; Scott, Larry

    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…

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

    PubMed Central

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

    2014-01-01

    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

  10. 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. ... a nerve biopsy. There is no cure. The disease can be so mild you don't realize ...

  11. Charcot-Marie-Tooth Disease

    MedlinePLUS

    ... and has not been passed down through the family. What are the types of Charcot-Marie-Tooth disease? There are many forms of CMT disease, including CMT1, CMT2, CMT3, CMT4, and CMTX. CMT1, caused by abnormalities in the myelin sheath, has three main types. ...

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

    PubMed

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

    2014-01-01

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

  13. An automatic and effective tooth isolation method for dental radiographs

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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.

  14. Zirconia Implants in Esthetic Areas: 4-Year Follow-Up Evaluation Study

    PubMed Central

    Borgonovo, Andrea Enrico; Censi, Rachele; Vavassori, Virna; Arnaboldi, Oscar; Maiorana, Carlo

    2015-01-01

    Objectives. The aim is to evaluate the survival and success rates, as well as the marginal bone loss (MBL) and periodontal indexes of zirconia implants positioned in the esthetic jaw areas. Materials and Method. 13 patients were selected and 20 one-piece zirconia implants were used for the rehabilitation of single tooth or partially edentulous ridge in the esthetic jaw areas. Six months after surgery and then once a year, a clinical-radiographic evaluation was performed in order to estimate peri-implant tissue health and marginal bone loss. Results. The survival and success rates were 100%. The average marginal bone loss from baseline to 48 months after surgery was +2.1?mm. Four years after surgery, the median and the mode for visible Plaque Index and Bleeding On Probing resulted 1 whereas Probing Pocket Depth amounted to 3?mm (SD = ±0.49?mm). Conclusion. One-piece zirconia dental implants are characterized by high biocompatibility, low plaque adhesion, and absence of microgap that can be related to the clinical success of these implants even in the esthetic areas.

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

    PubMed Central

    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

    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. PMID:25848369

  16. Analysis of Long-Term Survival Following Transcatheter Aortic Valve Implantation from a Single High-Volume Center.

    PubMed

    Escárcega, Ricardo O; Lipinski, Michael J; Baker, Nevin C; Magalhaes, Marco A; Minha, Sa'ar; Torguson, Rebecca; Chen, Fang; Ben-Dor, Itsik; Satler, Lowell F; Pichard, Augusto D; Corso, Paul; Waksman, Ron

    2015-07-15

    Mortality after transcatheter aortic valve implantation (TAVI) has been reported to range up to 3 years. However, long-term mortality remains underexplored. The aims of this study were to determine long-term mortality in patients who undergo TAVI and to identify correlates of long-term death. From a single institution's prospectively collected TAVI database, all patients who underwent TAVI with a maximum follow-up duration of 5 years were analyzed. The population was analyzed on the basis of access route (transapical TAVI or transfemoral TAVI). Cox regression and Kaplan-Meier survival analysis were conducted. A total of 511 patients who underwent TAVI were included in the analysis (transapical TAVI n = 115, transfemoral TAVI n = 396). The mean Society of Thoracic Surgeons score was 9.6 ± 4. Mortality at 30 days (18% vs 6%, p <0.001) and 1 year (32% vs 21%, p <0.01) was significantly increased in the transapical TAVI group. Long-term survival probability was <50% for the 2 approaches (log-rank p = 0.33). Vascular complications (hazard ratio [HR] 2.14, 95% confidence interval [CI] 1.38 to 3.33, p = 0.001), more than mild aortic insufficiency (HR 1.81, 95% CI 1.15 to 2.83, p = 0.01), atrial fibrillation (HR 1.87, 95% CI 1.36 to 2.57, p <0.001), and in-hospital stroke (HR 2.35, 95% CI 1.39 to 4.00, p = 0.002) were independently associated with long-term death. The survival probability of patients at high surgical risk versus those who were inoperable was similar in the long term (log-rank p = 0.53). In conclusion, the overall long-term survival of patients with aortic stenosis who were approved to undergo TAVI was <50% irrespective of access method. Strategies geared toward reducing in-hospital stroke, vascular complications, and aortic regurgitation are still needed, as these variables are correlates of long-term mortality. PMID:25978977

  17. Consideration of Moving Tooth Load in Gear Crack Propagation Predictions

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  18. Tooth emergence in Australian Aboriginals.

    PubMed

    Brown, T

    1978-01-01

    Patterns of dental development in 125 Australian Aboriginal boys and girls, in a growth study at Yuendumu in the Northern Territory of Australia, were compared with Australians of European origin using mean tooth emergence curves constructed from the emergence times of right and left side permanent teeth. There were two active phases of tooth emergence separated by a quiescent period of 1.4 years in boys and 1.0 years in girls. Phase one included emergence of the first 12 teeth, that is the first permanent molars and all incisors; phase two included emergence of the canines, premolars and second molars. In Aboriginal girls most teeth emerged earlier than in boys. Compared with the European-descended, the Aboriginal children displayed earlier emergence of most teeth during phase two and a shorter quiescent period between the two phases, an emergence pattern similar to that reported in other non-European populations. In Aboriginals the process tooth emergence and subsequent alignment is aided by adequate space and compensatory bone growth growth in the alveolar regions. These factors, as well as the genetic differences between groups, contribute to the earlier emergence of teeth during phase two in the Aboriginal children. PMID:646323

  19. An evidence-based concept of implant dentistry. Utilization of short and narrow platform implants.

    PubMed

    Ruiz, Jose-Luis

    2012-09-01

    As a profession, we must remember that tooth replacement is not a luxury; it is often a necessity for health reasons. Although bone augmentation and CBCT and expensive surgical guides are often indicated for complex cases, they are being overused. Simple or straightforward implant cases, when there is sufficient natural bone for narrow or shorter implant, can be predictable performed by well-trained GPs and other trained specialists. Complex cases requiring bone augmentation and other complexities as described herein, should be referred to a surgical specialist. Implant courses and curricula have to be based on the level of complexity of implant surgery that each clinician wishes to provide to his or her patients. Using a "logical approach" to implant dentistry keeps cases simple or straightforward, and more accessible to patients by the correct use of narrow and shorter implants. PMID:23019853

  20. Simultaneous Bilateral Cochlear Implantation in Adults: A Multicenter Clinical Study

    E-print Network

    Litovsky, Ruth

    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

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

    PubMed

    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

    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

  2. Vagal nerve stimulation for refractory epilepsy: the surgical procedure and complications in 100 implantations by a single medical center.

    PubMed

    Horowitz, Gilad; Amit, Moran; Fried, Itzhak; Neufeld, Miri Y; Sharf, Liad; Kramer, Uri; Fliss, Dan M

    2013-01-01

    In 1997, the US Food and Drug Administration approved the use of intermittent stimulation of the left vagal nerve as adjunctive therapy for seizure control. Vagal nerve stimulation (VNS) has since been considered a safe and effective treatment for medically intractable seizures. The objective of this study is to present our experience with the surgical procedure and outcomes after VNS insertion in the first 100 consecutive patients treated at the Tel-Aviv "Sourasky" Medical Center (TASMC). All patients who underwent VNS device implantation by the authors at TASMC between 2005 and 2011 were studied. The collected data included age at onset of epilepsy, seizure type, duration of epilepsy, age at VNS device implantation, seizure reduction, surgical complications, and adverse effects of VNS over time. Fifty-three males and 47 females, age 21.2 ± 11.1 years, underwent VNS implantation. Indications for surgery were medically refractory epilepsy. The most common seizure type was focal (55 patients, 55 %). Seizure duration until implantation was 14.4 ± 9 years. Mean follow-up time after device insertion was 24.5 ± 22 months. Complications were encountered in 12 patients. The most common complication was local infection (6 patients, 6 %). Six devices were removed-four due to infection and two due to loss of clinical effect. Currently, 63 patients remain in active long-term follow-up; of these, 35 patients have >50 % reduction in frequency of attacks.VNS is a well-tolerated and effective therapeutic alternative in the management of medically refractory epilepsy. The surgical procedure is safe and has a low complication rate. PMID:22836871

  3. Placing Dental Implants

    MedlinePLUS

    Placing Dental Implants Before Placing an Implant Placing the Implants Complications from Surgery Implant Failure When you get implants, more ... Implant Most people are good candidates to get dental implants. You must have enough bone in your jaw ...

  4. Tooth fragment reattachment: An esthetic, biological restoration

    PubMed Central

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

    2015-01-01

    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. PMID:25810662

  5. Nuclear-chemical methods in a hard tooth tissue abrasion study

    NASA Astrophysics Data System (ADS)

    Gosman, A.; Sp?vá?ek, V.; Koní?ek, J.; Vopálka, D.; Hou?ová, D.; Doležalová, L.

    1999-01-01

    The advanced method consists in implantation—labelling of the thin surface layers of the solid objects, e.g. hard tooth tissue, by atoms of suitable natural or artificial radionuclides. Nuclides from the uranium series were implanted into the surface by using nuclear recoil effect at alpha decay of 226Ra to 222Rn, alpha decay of 222Rn to RaA, alpha decay of RaA to RaB (beta-emitter) and further alpha or beta emitters. With regard to chosen alpha detection and to the half—lives of the radionuclides, there was actually measured the activity of 222Rn, RaA and RaC’ in the thin surface layer. This was followed by the laboratory simulation of the abrasion in the system of “toothbrush—various suspensions of the tooth-pastes—hard tooth tissue (or material standard—ivory)” in specially designed device—the dentoabrasionmeter. The activities of the tissue surface measured before and after abrasion were used for calculations of the relative drop of the surface activity. On this basis the influence of various tooth-pastes containing various abrasive substances was determined.

  6. Mechanisms of Tooth Eruption and Orthodontic Tooth Movement

    PubMed Central

    Wise, G.E.; King, G.J.

    2008-01-01

    Teeth move through alveolar bone, whether through the normal process of tooth eruption or by strains generated by orthodontic appliances. Both eruption and orthodontics accomplish this feat through similar fundamental biological processes, osteoclastogenesis and osteogenesis, but there are differences that make their mechanisms unique. A better appreciation of the molecular and cellular events that regulate osteoclastogenesis and osteogenesis in eruption and orthodontics is not only central to our understanding of how these processes occur, but also is needed for ultimate development of the means to control them. Possible future studies in these areas are also discussed, with particular emphasis on translation of fundamental knowledge to improve dental treatments. PMID:18434571

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

    PubMed

    Kokane, Vandana B; Patil, Swapnil N

    2014-12-01

    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

  8. Human Umbilical Cord Mesenchymal Stem Cells: A New Therapeutic Option for Tooth Regeneration

    PubMed Central

    Chen, Yuanwei; Yu, Yongchun; Chen, Lin; Ye, Lanfeng; Cui, Junhui; Sun, Quan; Li, Kaide; Li, Zhiyong; Liu, Lei

    2015-01-01

    Tooth regeneration is considered to be an optimistic approach to replace current treatments for tooth loss. It is important to determine the most suitable seed cells for tooth regeneration. Recently, human umbilical cord mesenchymal stem cells (hUCMSCs) have been regarded as a promising candidate for tissue regeneration. However, it has not been reported whether hUCMSCs can be employed in tooth regeneration. Here, we report that hUCMSCs can be induced into odontoblast-like cells in vitro and in vivo. Induced hUCMSCs expressed dentin-related proteins including dentin sialoprotein (DSP) and dentin matrix protein-1 (DMP-1), and their gene expression levels were similar to those in native pulp tissue cells. Moreover, DSP- and DMP-1-positive calcifications were observed after implantation of hUCMSCs in vivo. These findings reveal that hUCMSCs have an odontogenic differentiation potency to differentiate to odontoblast-like cells with characteristic deposition of dentin-like matrix in vivo. This study clearly demonstrates hUCMSCs as an alternative therapeutic cell source for tooth regeneration.

  9. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...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...

  10. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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...

  11. Charcot–Marie–Tooth disease

    PubMed Central

    Szigeti, Kinga; Lupski, James R

    2009-01-01

    Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of genetic disorders presenting with the phenotype of a chronic progressive neuropathy affecting both the motor and sensory nerves. During the last decade over two dozen genes have been identified in which mutations cause CMT. The disease illustrates a multitude of genetic principles, including diverse mutational mechanisms from point mutations to copy number variation (CNV), allelic heterogeneity, age-dependent penetrance and variable expressivity. Population based studies have determined the contributions of the various genes to disease burden enabling evidence-based approaches to genetic testing. PMID:19277060

  12. A Retrospective Analysis of Ruptured Breast Implants

    PubMed Central

    Baek, Woo Yeol; Lew, Dae Hyun

    2014-01-01

    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

  13. Immediate placement of endosseous implants into the extraction sockets

    PubMed Central

    Ebenezer, Vijay; Balakrishnan, K.; Asir, R. Vigil Dev; Sragunar, Banu

    2015-01-01

    Implant by definition “means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose.” The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone formation after the loss of tooth/teeth. Recent idea goes by “why late when it can be done immediately.” There are several advantages of immediate placement of implants, and lots of studies have been done. In this article, the advantages and disadvantages of immediate versus delayed placement of implants have been reviewed. PMID:26015721

  14. Periodontio-integrated implants: A revolutionary concept.

    PubMed

    Gulati, Minkle; Anand, Vishal; Govila, Vivek; Jain, Nikil; Rastogi, Pavitra; Bahuguna, Rohit; Anand, Bhargavi

    2014-03-01

    Though the fields of regenerative dentistry and tissue engineering have undergone significant advancements, yet its application to the field of implant-dentistry is lacking; in the sense that presently the implants are being placed with the aim of attaining osseointegration without giving consideration to the regeneration of periodontium around the implant. The following article reveals the clinical benefits of such periodontio-integrated implants and reviews the relevant scientific proofs. A comprehensive research to provide scientific evidence supporting the feasibility of periodontio-integrated implants was carried out using various online resources such as PubMed, Wiley-Blackwell, Elsevier etc., to retrieve studies published between 1980 and 2012 using the following key words: "implant," "tissue engineering," "periodontium," "osseo-integration," "osseoperception," "regeneration" (and their synonyms) and it was found that in the past three decades, several successful experiments have been conducted to devise "implant supported by the periodontium"that can maintain form, function and potential proprioceptive responses similar to a natural tooth. Based on these staunch evidences, the possibility of the future clinical use of such implant can be strongly stated which would revolutionize the implant dentistry and will be favored by the patients as well. However, further studies are required to validate the same. PMID:24932184

  15. [Complications after cosmetic iris implantation].

    PubMed

    Jonsson, N J; Sahlmüller, M C; Ruokonen, P C; Torun, N; Rieck, P

    2011-05-01

    We report the case of a 37-year-old patient with ocular complications associated with the implantation of cosmetic iris implants. Implantation of silicone iris implants for the purpose of changing iris colour has been performed since 2004. Diaphragms are implanted in the anterior chamber. Up to now only little information exists about side effects of this method. In the literature severe ocular complications shortly after cosmetic iris implantation are reported in single cases. In our case 5 months after surgery optic nerve damage caused by elevated intraocular pressure (IOP) was diagnosed. Nuclear opacity of both lenses and a decreased number of corneal endothelial cells were observed at the first visit. Because of recurrent IOP elevation despite maximum antiglaucoma therapy, explantation of the iris implants was required. Damage to the trabecular meshwork, opacity of the lenses as well as the reduced number of endothelial cells are permanent and will probably lead to further complications like corneal decompensation and progressing glaucoma. PMID:21344246

  16. 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 ...

  17. Ion channels, channelopathies, and tooth formation.

    PubMed

    Duan, X

    2014-02-01

    The biological functions of ion channels in tooth development vary according to the nature of their gating, the species of ions passing through those gates, the number of gates, localization of channels, tissue expressing the channel, and interactions between cells and microenvironment. Ion channels feature unique and specific ion flux in ameloblasts, odontoblasts, and other tooth-specific cell lineages. Both enamel and dentin have active chemical systems orchestrating a variety of ion exchanges and demineralization and remineralization processes in a stage-dependent manner. An important role for ion channels is to regulate and maintain the calcium and pH homeostasis that are critical for proper enamel and dentin biomineralization. Specific functions of chloride channels, TRPVs, calcium channels, potassium channels, and solute carrier superfamily members in tooth formation have been gradually clarified in recent years. Mutations in these ion channels or transporters often result in disastrous changes in tooth development. The channelopathies of tooth include altered eruption (CLCN7, KCNJ2, TRPV3), root dysplasia (CLCN7, KCNJ2), amelogenesis imperfecta (KCNJ1, CFTR, AE2, CACNA1C, GJA1), dentin dysplasia (CLCN5), small teeth (CACNA1C, GJA1), tooth agenesis (CLCN7), and other impairments. The mechanisms leading to tooth channelopathies are primarily related to pH regulation, calcium homeostasis, or other alterations of the niche for tooth eruption and development. PMID:24076519

  18. Charcot-Marie-Tooth disease

    PubMed Central

    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

    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

  19. Graphene-based wireless bacteria detection on tooth enamel

    NASA Astrophysics Data System (ADS)

    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

    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.

  20. Graphene-based wireless bacteria detection on tooth enamel.

    PubMed

    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

    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

  1. Controlling the Number of Tooth Rows

    NSDL National Science Digital Library

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

    2009-08-25

    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.

  2. Tooth Whitening: What We Now Know

    PubMed Central

    Carey, Clifton M.

    2014-01-01

    Declarative Title Current research about tooth whitening shows that it is safe and effective when manufacturer’s protocol is followed, yet there are risks of which the profession and users should be aware. This update provides a summary of current research and assessment of the safety and efficacy of tooth whitening regimens. Background Tooth whitening has become one of the most frequently requested dental procedures by the public. The public has come to demand whiter, more perfect smiles and in response many choices for tooth whitening have been made available. These include home-based products such as toothpastes, gels, and films, as well as in-office based systems where products containing highly concentrated bleaching agents are applied under professional supervision. The profession and public have been aware of certain risks related to tooth whitening such as increased tooth sensitivity and gingival irritation. New research has shown that there are other risks such as tooth surface roughening and softening, increased potential for demineralization, degradation of dental restorations, and unacceptable color change of dental restorations. The new research is also focused on optimizing whitening procedures to reduce tooth sensitivity and to increase the persistence of the whitening. Methods Current reports in the literature are reviewed that are related to the use of peroxide based whitening methods. These reports include in vitro studies for method optimization and mechanism as well as clinical studies on effects of various whitening regimens. Conclusions When manufacturer’s instructions are followed, hydrogen peroxide and carbamide peroxide based tooth whitening is safe and effective. Patients should be informed of the risks associated with tooth whitening and instructed on identification of adverse occurrences so that they may seek professional help asneeded. PMID:24929591

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

    SciTech Connect

    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

    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.

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

    Microsoft Academic Search

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

    The long-term success of osseointegrated oral implants is endangered by inflammation of peri-implant hard and soft tissues\\u000a caused by bacterial biofilms that may have been initiated by bacterial transmission from the adjacent dentition. The present\\u000a study aimed to compare the bacterial communities at inflamed implant and tooth sites by broad-range PCR techniques to evaluate\\u000a the etiological processes of peri-implant and

  5. The effect of framework design on fracture resistance of metal-ceramic implant-supported single crowns.

    PubMed

    de Oliveira, José Luiz G; Martins, Leandro Moura; Sanada, Jeffeson; de Oliveira, Pedro Cesar G; do Valle, Accácio L

    2010-01-01

    This study evaluated the effect of framework design on the fracture resistance of metal-ceramic implant-supported crowns. Screw-retained molar crowns with a screw access hole composed of metal or porcelain were compared to a cement-retained crown (control). For each group (n = 10), five crowns were subjected to dynamic loading (1,200,000 x 100 N x 2 Hz at 37 degrees C). Afterward, all specimens were loaded to failure using a universal testing machine. Significant differences could be established between the cement- and screw-retained groups (P = or < .05), but no difference was found between the screw-retained groups and the specimens subjected to dynamic loading. Occlusal discontinuity of screw-retained crowns affects their resistance, and the metallic support on the screw access hole did not reinforce the crowns. PMID:20617225

  6. Transvenous removal of pacing and implantable cardiac defibrillating leads using single sheath mechanical dilatation and multiple venous approaches: high success rate and safety in more than 2000 leads

    PubMed Central

    Bongiorni, Maria Grazia; Soldati, Ezio; Zucchelli, Giulio; Di Cori, Andrea; Segreti, Luca; De Lucia, Raffaele; Solarino, Gianluca; Balbarini, Alberto; Marzilli, Mario; Mariani, Mario

    2008-01-01

    Aims The aim of the present study was to describe a 10 years single-centre experience in pacing and defibrillating leads removal using an effective and safe modified mechanical dilatation technique. Methods and results We developed a single mechanical dilating sheath extraction technique with multiple venous entry site approaches. We performed a venous entry site approach (VEA) in cases of exposed leads and an alternative transvenous femoral approach (TFA) combined with an internal transjugular approach (ITA) in the presence of very tight binding sites causing failure of VEA extraction or in cases of free-floating leads. We attempted to remove 2062 leads [1825 pacing and 237 implantable cardiac defibrillating (ICD) leads; 1989 exposed at the venous entry site and 73 free-floating] in 1193 consecutive patients. The VEA was effective in 1799 leads, the TFA in 28, and the ITA in 205; in the overall population, we completely removed 2032 leads (98.4%), partially removed 18 (0.9%), and failed to remove 12 leads (0.6%). Major complications were observed in eight patients (0.7%), causing three deaths (0.3%). Conclusion Mechanical single sheath extraction technique with multiple venous entry site approaches is effective, safe, and with a good cost effective profile for pacing and ICD leads removal. PMID:18948356

  7. Tooth bleaching with nonthermal atmospheric pressure plasma.

    PubMed

    Lee, Hyun Woo; Kim, Gon Jun; Kim, Jae Moon; Park, Jeong Kil; Lee, Jae Koo; Kim, Gyoo Cheon

    2009-04-01

    We demonstrated that room temperature plasma could be used for tooth bleaching. A nonthermal, atmospheric pressure, helium plasma jet device was developed to enhance the tooth bleaching effect of hydrogen peroxide (H(2)O(2)). All teeth were sectioned sagittally into halves, which were assigned randomly to either the experimental group or the control group. The experimental group was treated with H(2)O(2) (28%, 20 microL every 30 seconds) plus plasma (5 W) for 10 minutes; the control group was treated with H(2)O(2) alone for the same duration. Removal of the tooth surface protein was demonstrated by scanning electron microscopy images and Ponceau staining. Production of hydroxyl radicals (.OH) was measured by using electron spin resonance spin-trapping. Combining plasma and H(2)O(2) improved the bleaching efficacy by a factor of 3 compared with using H(2)O(2) alone. Tooth surface proteins were noticeably removed by plasma treatment. When a piece of tooth was added to a solution of H(2)O(2) as a catalyst, production of *OH after plasma treatment was 1.9 times greater than when using H(2)O(2) alone. We suggest that the improvement in tooth bleaching induced by plasma is due to the removal of tooth surface proteins and to increased *OH production. PMID:19345811

  8. Development of A Dental Implant Navigation System in Thailand

    Microsoft Academic Search

    Jackrit Suthakorn; Auranuch Lorsakul; Chanjira Sinthanayothin; Wichit Tharanont

    4 PURPOSE: Dental implant is one of the most popular methods of tooth root replacement used in prosthetic dentistry. Computerize navigation system on a pre-surgical plan is offered to minimize potential risk of damage to critical anatomic structures of patients. The methodology is based on Computer Integrated Surgery (CIS) interventions which includes preoperative and intraoperative procedures. The preoperative surgery requires

  9. Biofilm and dental implant: The microbial link

    PubMed Central

    Dhir, Sangeeta

    2013-01-01

    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

  10. Second-harmonic generation microscopy of tooth

    NASA Astrophysics Data System (ADS)

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

    2000-07-01

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

  11. Soft Tissue Surgical Procedures for Optimizing Anterior Implant Esthetics

    PubMed Central

    Ioannou, Andreas L.; Kotsakis, Georgios A.; McHale, Michelle G.; Lareau, Donald E.; Hinrichs, James E.; Romanos, Georgios E.

    2015-01-01

    Implant dentistry has been established as a predictable treatment with excellent clinical success to replace missing or nonrestorable teeth. A successful esthetic implant reconstruction is predicated on two fundamental components: the reproduction of the natural tooth characteristics on the implant crown and the establishment of soft tissue housing that will simulate a healthy periodontium. In order for an implant to optimally rehabilitate esthetics, the peri-implant soft tissues must be preserved and/or augmented by means of periodontal surgical procedures. Clinicians who practice implant dentistry should strive to achieve an esthetically successful outcome beyond just osseointegration. Knowledge of a variety of available techniques and proper treatment planning enables the clinician to meet the ever-increasing esthetic demands as requested by patients. The purpose of this paper is to enhance the implant surgeon's rationale and techniques beyond that of simply placing a functional restoration in an edentulous site to a level whereby an implant-supported restoration is placed in reconstructed soft tissue, so the site is indiscernible from a natural tooth.

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

    PubMed Central

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

    2015-01-01

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

  13. Influence of tooth modifications on tooth contact in face-hobbed spiral bevel gears

    Microsoft Academic Search

    Vilmos V. Simon

    2011-01-01

    In this study the influence of tooth modifications induced by machine tool setting and head-cutter profile variations on tooth contact characteristics in face-hobbed spiral bevel gears is investigated. The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. The modifications of tooth surfaces are introduced into the teeth of both members. The lengthwise crowning

  14. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth...6660) intended for use in construction of fixed or removable prostheses, such as crowns and partial dentures. (b)...

  15. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth...6660) intended for use in construction of fixed or removable prostheses, such as crowns and partial dentures. (b)...

  16. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...3920 Food and Drugs 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...

  17. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3920 Food and Drugs 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...

  18. 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- ... need to be treated right away? Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI) DIFOTI uses a bright light ...

  19. High Productivity Implantation ''PARTIAL IMPLANT''

    SciTech Connect

    Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao [Nissin Ion Equipment Co., LTD., Kyoto (Japan)

    2008-11-03

    The patterned ion implantation 'PARTIAL IMPLANT' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is 'DIVIDE PARTIAL IMPLANT', that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is 'RING PARTIAL IMPLANT' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

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

    PubMed

    Warpeha, Walter S

    2014-01-01

    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

  1. Breast Implants

    MedlinePLUS

    ... filled breast implants, including data supporting a reasonable assurance of safety and effectiveness, approval letters, labeling and information on post-approval studies. Provide information on reports ...

  2. Ion Implantation

    NASA Astrophysics Data System (ADS)

    Langouche, G.; Yoshida, Y.

    In this tutorial we describe the basic principles of the ion implantation technique and we demonstrate that emission Mössbauer spectroscopy is an extremely powerful technique to investigate the atomic and electronic configuration around implanted atoms. The physics of dilute atoms in materials, the final lattice sites and their chemical state as well as diffusion phenomena can be studied. We focus on the latest developments of implantation Mössbauer spectroscopy, where three accelerator facilities, i.e., Hahn-Meitner Institute Berlin, ISOLDE-CERN and RIKEN, have intensively been used for materials research in in-beam and on-line Mössbauer experiments immediately after implantation of the nuclear probes.

  3. Immediate implants in anterior maxillary arch

    PubMed Central

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

    2014-01-01

    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

  4. Annealing-Environment Effects on the Properties of CoPt Nanoparticles Formed in Single-Crystal Al2O3 by Ion Implantation

    SciTech Connect

    White, Clark W [ORNL; Withrow, Stephen P [ORNL; Budai, John D [ORNL; Thomas, Darrell Keith [ORNL; Williams, J. M. [BronteK Delta Corporation; Meldrum, A. [University of Alberta, Edmondton, Canada; Sorge, K. D. [University of Nebraska, Lincoln; Thompson, James R [ORNL; Ownby, Gary Webb [ORNL; Wendelken, J F [ORNL; Boatner, Lynn A [ORNL

    2005-01-01

    The ion implantation of nearly equal doses of Co and Pt into a single-crystal Al{sub 2}O{sub 3} host followed by thermal annealing leads to the formation of nanoparticles whose phase, structure, and physical properties are strongly dependent on the annealing environment. Annealing in 96%Ar+4%H{sub 2} gives rise to ferromagnetic, chemically ordered CoPt nanoparticles with the L1{sub 0} structure and a magnetic coercivity that can exceed 10 kOe at 5 K. Annealing in O{sub 2} (or in Ar) does not result in the formation of a CoPt alloy. Instead, the implanted Pt precipitates to form oriented elemental Pt nanoparticles, and the implanted Co combines with oxygen to form Co{sub 3}O{sub 4} oxide nanoparticles. Annealing in ultrahigh-vacuum conditions results in a mixture of phases including CoPt{sub 3} and Co{sub 3}O{sub 4} and possibly Co. The results obtained for Co+Pt-implanted Al{sub 2}O{sub 3} are compared with the previous results for Fe+Pt-implanted Al{sub 2}O{sub 3} annealed in similar environments.

  5. Roles of Bmp4 during tooth morphogenesis and sequential tooth formation

    PubMed Central

    Jia, Shihai; Zhou, Jing; Gao, Yang; Baek, Jin-A; Martin, James F.; Lan, Yu; Jiang, Rulang

    2013-01-01

    Previous studies have suggested that Bmp4 is a key Msx1-dependent mesenchymal odontogenic signal for driving tooth morphogenesis through the bud-to-cap transition. Whereas all tooth germs were arrested at the bud stage in Msx1–/– mice, we show that depleting functional Bmp4 mRNAs in the tooth mesenchyme, through neural crest-specific gene inactivation in Bmp4f/f;Wnt1Cre mice, caused mandibular molar developmental arrest at the bud stage but allowed maxillary molars and incisors to develop to mineralized teeth. We found that expression of Osr2, which encodes a zinc finger protein that antagonizes Msx1-mediated activation of odontogenic mesenchyme, was significantly upregulated in the molar tooth mesenchyme in Bmp4f/f;Wnt1Cre embryos. Msx1 heterozygosity enhanced maxillary molar developmental defects whereas Osr2 heterozygosity partially rescued mandibular first molar morphogenesis in Bmp4f/f;Wnt1Cre mice. Moreover, in contrast to complete lack of supernumerary tooth initiation in Msx1–/–Osr2–/– mice, Osr2–/–Bmp4f/f;Wnt1Cre compound mutant mice exhibited formation and subsequent arrest of supernumerary tooth germs that correlated with downregulation of Msx1 expression in the tooth mesenchyme. In addition, we found that the Wnt inhibitors Dkk2 and Wif1 were much more abundantly expressed in the mandibular than maxillary molar mesenchyme in wild-type embryos and that Dkk2 expression was significantly upregulated in the molar mesenchyme in Bmp4f/f;Wnt1Cre embryos, which correlated with the dramatic differences in maxillary and mandibular molar phenotypes in Bmp4f/f;Wnt1Cre mice. Together, these data indicate that Bmp4 signaling suppresses tooth developmental inhibitors in the tooth mesenchyme, including Dkk2 and Osr2, and synergizes with Msx1 to activate mesenchymal odontogenic potential for tooth morphogenesis and sequential tooth formation. PMID:23250216

  6. Twin disc gear tooth simulator

    NASA Astrophysics Data System (ADS)

    Eusepi, Martin W.; Dill, James F.

    1994-05-01

    This report describes the results of an effort to develop a disc on disc test rig for evaluating lubricant load capacity. The goal of the program has been to develop a reliable disc on disc (or Twin Disc) test rig capable of providing more reliable and lower cost evaluation of lubricant load capacity than the Ryder gear test which is currently used. Disc rigs have been evaluated for this application in the past, but have failed to provide scuffing results which are comparable to those found in gear tests. The unique feature of the rig designed and evaluated under this program is a drive system design which varies the disc to disc sliding and rolling speeds in a fixed manner to simulate the combined rolling and sliding motion found in a gear tooth contact. Other features include a drive system design which insures that the same points on each disc always contact each other as they rotate, and material selection and heating system design for operation with experimental lubricants at temperatures up to 700 deg F.

  7. 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

    2014-01-01

    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

  8. Tooth Wear Prevalence and Sample Size Determination : A Pilot Study

    PubMed Central

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

    2008-01-01

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

  9. The development of the tooth pattern and dentigerous bones in Polypterus senegalus (Cladistia, Actinopterygii).

    PubMed

    Wacker, K; Bartsch, P; Clemen, G

    2001-01-01

    The formation sequence of the tooth-bearing bones and the tooth pattern in early ontogeny of Polypterus senegalus is investigated using transparent preparation, histological sections, and SEM. During the attachment step of the yolk-sac larva the first dermal bones and teeth are formed. Teeth appear simultaneously in the areas of the maxillary, dentary, dermopalatine, prearticular, and coronoid 1 along with the first separate anlagen of these bones. A monostichous arrangement of primary teeth is established on the maxillary, dentary, and dermopalatine. Polystichous tooth arrangements do not occur before the early pterolarval phase, and then only in connection with bones of the palate and inner dental arcades. Especially pronounced is the influence of tooth formation on the structure of the parasphenoid that becomes much thickened by accretion of denticulate platelets, but we found neither evidence for a distinct vomeral contribution to the parasphenoid, nor a composite origin of the ectopterygoid in ontogeny. First replacement teeth are found in association with the maxillary and dentary as early as the late apterolarval phase. Primary teeth are of a single general type, whereas from the pterolarval phase onward three tooth types can be distinguished that are restricted to certain tooth bearing bones. Relatively late in ontogeny, dermo-metapterygoid and entopterygoid become formed and colonised by teeth, whereas first branchial teeth and tooth plates appear earlier during the first phase of extrinsic larval feeding. Characteristics of development of the dentition are discussed in comparison with character states of other better known fossil and recent taxa among Actinopterygii and Sarcopterygii. Compared to the assumed basic pattern of actinopterygian fishes, Polypteriformes show a derived condition with respect to structure, arrangement, replacement, and differentiation of teeth, which arises in sequence during larval development. This also corresponds to observed changes of feeding behaviour and functional demands during larval life. PMID:11206982

  10. RAPID COMMUNICATION: Epitaxial CoSi2 layers fabricated by a single-step technique of high-current Co-ion implantation

    NASA Astrophysics Data System (ADS)

    Zhu, H. N.; Liu, B. X.

    1999-12-01

    In this communication, the plain and continuous epitaxial CoSi2 was first synthesized on Si(111) wafers with metal vacuum vapour arc ion implantation without in situ heating or post-annealing. The measurements on the CoSi2 layers showed that increasing the formation temperature and the implantation dose can improve the crystallinity of CoSi2.

  11. 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

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

    2009-01-01

    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…

  12. 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

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

    2009-01-01

    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

  13. Implant ethics

    PubMed Central

    Hansson, S

    2005-01-01

    Implant ethics is defined here as the study of ethical aspects of the lasting introduction of technological devices into the human body. Whereas technological implants relieve us of some of the ethical problems connected with transplantation, other difficulties arise that are in need of careful analysis. A systematic approach to implant ethics is proposed. The major specific problems are identified as those concerning end of life issues (turning off devices), enhancement of human capabilities beyond normal levels, mental changes and personal identity, and cultural effects. PMID:16131553

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

    PubMed Central

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

    2014-01-01

    INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventional panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%. PMID:25715716

  15. Tooth-derived bone graft material

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

    Zou, Bei-ji; Liu, Shi-jian; Liao, Sheng-hui; Ding, Xi; Liang, Ye

    2015-01-01

    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

  17. Histrelin Implant

    MedlinePLUS

    ... used to treat the symptoms associated with advanced prostate cancer. Histrelin implant (Supprelin LA) is used to ... to use certain tests, such as ultrasound or MRI scans (radiology techniques designed to show the images ...

  18. Conversion of an existing metal ceramic crown to an interim restoration and nonfunctional loading of a single implant in the maxillary esthetic zone: A clinical report.

    PubMed

    Michalakis, Konstantinos; Kalpidis, Christos D R; Hirayama, Hiroshi

    2014-01-01

    Implant placement and immediate placement of an interim restoration can be a safe therapeutic approach with high survival rates. The technique is often used in the anterior esthetic area because of the better preservation of the periimplant soft tissue contours. Traditionally this procedure involves the fabrication of an acrylic resin implant-supported interim restoration. This clinical report describes the modification of an existing metal ceramic crown to be used as an implant-supported interim restoration for immediate nonfunctional loading to achieve an improved esthetic result and optimal support of the adjacent soft tissues. PMID:24231435

  19. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth...interior of a prepared cavity of a tooth to improve retention of a restoration, such as a filling. (b) Classification. Class...

  20. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth...interior of a prepared cavity of a tooth to improve retention of a restoration, such as a filling. (b) Classification. Class...

  1. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth...interior of a prepared cavity of a tooth to improve retention of a restoration, such as a filling. (b) Classification. Class...

  2. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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)...

  3. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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)...

  4. 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 ...

  5. Treatment imprudence leading to missed tooth fragment

    PubMed Central

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

    2013-01-01

    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

  6. Treatment imprudence leading to missed tooth fragment.

    PubMed

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

    2013-01-01

    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

  7. Danger: implants.

    PubMed

    Findlay, S; Podolsky, D

    1992-08-24

    The superheated debate over breast implants awakened a sleeping giant of an issue clouding "medical devices"--the government's clumsy nomenclature for any medical product that is not a drug, from breast implants and artificial hips to X-ray machines and surgical thread. Some 130 categories of high-risk devices are in use with little or no proof of safety, reliability or effectiveness. All appeared before 1976, the year that the Food and Drug Administration got the authority to regulate such products. Under activist chief David Kessler and with added clout from a 1990 law, the FDA plans to scrutinize the entire 130-item list. Five will get special attention starting early next year: saline-filled breast implants, inflatable penile implants, testicular implants, heart-bypass pumps and cranial stimulators. U.S. News has looked at all five devices, using FDA data obtained through the Freedom of Information Act. In-depth computer analysis suggested that penile implants deserve closer examination. Why is clear from the following report. PMID:10171242

  8. The Effect of Lubricants on Gear Tooth Scuffing

    Microsoft Academic Search

    P. M. Ku; B. B. Baber

    1959-01-01

    This paper discusses the effect of some lubricant variables and other relevant factors on gear tooth scuffing. Scuffing is defined as any form of scoring or abrasion of the tooth surface due to metal-to-metal contact. The scuff-limited load is defined as the tooth load at which an arbitrary amount of the working tooth area is scuffed. The factors considered include

  9. Tooth resorption in cats : contribution of vitamin D and inflammation

    Microsoft Academic Search

    H. E. Vrieling

    2010-01-01

    Tooth resorption affecting several teeth is a painful disease with a prevalence of up to 75% in household cats and is often accompanied by periodontitis. Tooth resorption is caused by an increased number and activity of tooth-resorbing odontoclasts, cells that share functional characteristics with bone-resorbing osteoclasts. Both vitamin D and inflammatory cytokines stimulate the formation and activity of osteoclasts. Most

  10. Impact of gin saw tooth design on textile processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toothed gin saws have been used to separate cotton fiber from the seed for over 200 years. There have been many saw tooth designs developed over the years. Most of these designs were developed by trial and error. A complete and scientific analysis of tooth design has never been done. It is not k...

  11. Investigations On Gear Tooth Surface And Bulk Temperatures Using ANSYS

    Microsoft Academic Search

    P R Thyla; R Rudramoorthy

    In gears, the temperature at the conjunction zone between the meshing tooth faces governs the imminent scuffing failure. Failure due to high tooth temperatures can be prevented with the knowledge of temperature distribution in gear teeth under operation. In this work, the prediction of bulk and surface temperatures of the gear tooth is carried out using finite element method, using

  12. The Importance of Tooth Decay Prevention in Children under Three

    ERIC Educational Resources Information Center

    Milgrom, Peter; Huebner, Colleen; Chi, Donald

    2010-01-01

    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…

  13. EPR dosimetry with tooth enamel: A review.

    PubMed

    Fattibene, Paola; Callens, Freddy

    2010-11-01

    When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed. PMID:20599388

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

    Microsoft Academic Search

    Jing Fan; Yih-Ing Hser; Diane Herbeck

    2006-01-01

    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

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

    PubMed Central

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

    2014-01-01

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

  16. Using a Cochlear Implant

    MedlinePLUS

    ... Vision Loss Using a Cochlear Implant Using a Cochlear Implant Note: This video may take several seconds to ... Cochlear Implant Video (Quicktime) Transcript of Using a Cochlear Implant Video NARRATOR: Mary, a woman with short gray ...

  17. Implantable Medical Devices

    MedlinePLUS

    Implantable Medical Devices Updated:Oct 23,2014 Implantable Medical Devices - 2 types 1. Rhythm control ICD -- Implantable cardioverter-defibrillator ( ... medical treatment. 2. Support of the Circulation Implantable Medical Devices Left Ventricular Assist Device (Also known as ...

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

    NASA Astrophysics Data System (ADS)

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

    2011-05-01

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

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

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

    2014-08-01

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

  1. [Navigated implant placement using a bone supported CT-guided surgical template. Case report].

    PubMed

    Teubner, Eckart; Rohner, Dennis; Deak, Alexander; Lorenzon, Andreas; Marinello, Carlo P

    2009-01-01

    Surgical navigation allows precise implant placement and minimizes the risk of interferences with anatomical structures. Computerized implant planning based on tomographic data can be clinically realized by surgical templates. These are normally produced by stereo lithographic rapid prototyping. Accurate placement of virtually planned dental implants depends on a precise fabrication and positioning of the surgical template. Bone-, tooth-, implant-, and/or soft tissue-supported surgical templates allow for different micromovements. This report documents the diagnostics and surgical procedures of implant placement in an edentulous patient. Implant fixed complete dentures in the maxilla and mandible were planned. In the maxilla implants were inserted with the aid of a conventional surgical template. In the mandible a bone supported CT-guided surgical template was used. PMID:20120091

  2. Static-transmission-error vibratory-excitation contributions from plastically deformed gear teeth caused by tooth bending-fatigue damage

    NASA Astrophysics Data System (ADS)

    Mark, W. D.; Reagor, C. P.

    2007-02-01

    To assess gear health and detect gear-tooth damage, the vibratory response from meshing gear-pair excitations is commonly monitored by accelerometers. In an earlier paper, strong evidence was presented suggesting that, in the case of tooth bending-fatigue damage, the principal source of detectable damage is whole-tooth plastic deformation; i.e. yielding, rather than changes in tooth stiffness caused by tooth-root cracks. Such plastic deformations are geometric deviation contributions to the "static-transmission-error" (STE) vibratory excitation caused by meshing gear pairs. The STE contributions caused by two likely occurring forms of such plastic deformations on a single tooth are derived, and displayed in the time domain as a function of involute "roll distance." Example calculations are provided for transverse contact ratios of Qt=1.4 and 1.8, for spur gears and for helical-gear axial contact ratios ranging from Qa=1.2 to Qa=3.6. Low-pass- and band-pass-filtered versions of these same STE contributions also are computed and displayed in the time domain. Several calculations, consisting of superposition of the computed STE tooth-meshing fundamental harmonic contribution and the band-pass STE contribution caused by a plastically deformed tooth, exhibit the amplitude and frequency or phase modulation character commonly observed in accelerometer-response waveforms caused by damaged teeth. General formulas are provided that enable computation of these STE vibratory-excitation contributions for any form of plastic deformation on any number of teeth for spur and helical gears with any contact ratios.

  3. 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

  4. Dynamic analysis of straight and involute tooth forms

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  5. Multilobed mesiodens: a supernumerary tooth with unusual morphology.

    PubMed

    Dave, Bhavna; Patel, Jalark; Swadas, Milan; Mallikarjuna, Rachappa

    2013-01-01

    An 8-year-old boy came with a chief complaint of an abnormally shaped tooth situated in upper front teeth region. On examination a supernumerary tooth with multiple lobes was present palatally to the maxillary right permanent central incisor. The morphology of the tooth crown was found to be unusual due to the presence of five lobes in the crown portion. Because of the supernumerary tooth, the permanent right central incisor was displaced labially. Radiographic examination showed a completely formed supernumerary tooth with dilacerated root. On the basis of clinical and radiographic examination, the supernumerary tooth was diagnosed as multilobed mesiodens. Since patient expressed dissatisfaction with the presence of supernumerary tooth, it was decided to extract this mesiodens followed by orthodontic treatment for alignment of labially placed maxillary right permanent central incisor. PMID:23391956

  6. Multilobed mesiodens: a supernumerary tooth with unusual morphology

    PubMed Central

    Dave, Bhavna; Patel, Jalark; Swadas, Milan; Mallikarjuna, Rachappa

    2013-01-01

    An 8-year-old boy came with a chief complaint of an abnormally shaped tooth situated in upper front teeth region. On examination a supernumerary tooth with multiple lobes was present palatally to the maxillary right permanent central incisor. The morphology of the tooth crown was found to be unusual due to the presence of five lobes in the crown portion. Because of the supernumerary tooth, the permanent right central incisor was displaced labially. Radiographic examination showed a completely formed supernumerary tooth with dilacerated root. On the basis of clinical and radiographic examination, the supernumerary tooth was diagnosed as multilobed mesiodens. Since patient expressed dissatisfaction with the presence of supernumerary tooth, it was decided to extract this mesiodens followed by orthodontic treatment for alignment of labially placed maxillary right permanent central incisor. PMID:23391956

  7. Paying for treatments? Influences on negotiating clinical need and decision-making for dental implant treatment

    PubMed Central

    Exley, Catherine E; Rousseau, Nikki S; Steele, Jimmy; Finch, Tracy; Field, James; Donaldson, Cam; Thomason, J Mark; May, Carl R; Ellis, Janice S

    2009-01-01

    Background The aim of this study is to examine how clinicians and patients negotiate clinical need and treatment decisions within a context of finite resources. Dental implant treatment is an effective treatment for missing teeth, but is only available via the NHS in some specific clinical circumstances. The majority of people who receive this treatment therefore pay privately, often at substantial cost to themselves. People are used to paying towards dental treatment costs. However, dental implant treatment is much more expensive than existing treatments – such as removable dentures. We know very little about how dentists make decisions about whether to offer such treatments, or what patients consider when deciding whether or not to pay for them. Methods/Design Mixed methods will be employed to provide insight and understanding into how clinical need is determined, and what influences people's decision making processes when deciding whether or not to pursue a dental implant treatment. Phase 1 will use a structured scoping questionnaire with all the General dental practitioners (GDPs) in three Primary Care Trust areas (n = 300) to provide base-line data about existing practice in relation to dental implant treatment, and to provide data to develop a systematic sampling procedure for Phase 2. Phases 2 (GDPs) and 3 (patients) use qualitative focused one to one interviews with a sample of these practitioners (up to 30) and their patients (up to 60) to examine their views and experiences of decision making in relation to dental implant treatment. Purposive sampling for phases 2 and 3 will be carried out to ensure participants represent a range of socio-economic circumstances, and choices made. Discussion Most dental implant treatment is conducted in primary care. Very little information was available prior to this study about the quantity and type of treatment carried out privately. It became apparent during phase 2 that ISOD treatment was an unusual treatment in primary care. We thus extended our sample criteria for Phase 3 to include people who had had other implant supported restorations, although not single tooth replacements. PMID:19138389

  8. Patient-specific analysis of periodontal and peri-implant microbiomes.

    PubMed

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

    2013-12-01

    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

  9. Patient-specific Analysis of Periodontal and Peri-implant Microbiomes

    PubMed Central

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

    2013-01-01

    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

  10. Three dimensional dental epithelial-mesenchymal constructs of predetermined size and shape for tooth regeneration.

    PubMed

    Zhang, Weibo; Ahluwalia, Ivy P; Yelick, Pamela C

    2010-11-01

    While it is known that precise dental epithelial-mesenchymal (DE-DM) cell interactions provide critical functions in tooth development, reliable methods to establish proper DE-DM cell interactions for tooth regeneration have yet to be established. To address this challenge, and to generate bioengineered teeth of predetermined size and shape, in this study, we characterize three dimensional (3D) pre-fabricated DE-DM cell constructs. Human dental pulp cell seeded Collagen gel layers were co-cultured with porcine DE cells suspended in Growth Factor Reduced (GFR) Matrigel. The resulting 3D DE-DM cell layers were cultured in vitro, or implanted and grown subcutaneously in vivo in nude rats. Molecular, histological and immunohistochemical (IHC) analyses of harvested implants revealed organized DE-DM cell interactions, the induced expression of dental tissue-specific markers Amelogenin (AM) and Dentin Sialophosphoprotein (DSPP), and basement membrane markers Laminin 5 and collagen IV, and irregular mineralized tissue formation after 4 weeks. We anticipate that these studies will facilitate the eventual establishment of reliable methods to elaborate dental tissues, and full sized teeth of specified sized and shape. PMID:20682455

  11. Immediate transmucosal implants using the principle of guided tissue regeneration. I. Rationale, clinical procedures and 30-month results.

    PubMed

    Lang, N P; Brägger, U; Hämmerle, C H; Sutter, F

    1994-09-01

    The installation of implants directly into extraction sockets offers considerable advantages over other treatment modalities for both practitioners and patients. Usually, immediate implants are placed and subsequently covered by mucosa allowing a submerged healing mode. This report presents the rationale, clinical procedures and results for immediate transmucosal implants. Following an intracrevicular incision and flap elevation, the tooth to be extracted is carefully luxated by means of small elevators to preserve the entire bony housing of the tooth. A titanium plasma-sprayed implant (ITI Bonefit) is then installed at the bottom or in the wall of the extraction socket. An expanded polytetrafluoroethylene barrier membrane (Gore-Tex GTAM) is tightly adapted around the implant post and over the bony margins of the alveolus. The flaps are then replaced, adapted around the neck of the implant and sutured. During nonsubmerged, transmucosal healing of the site, meticulous plaque control is performed by mechanical and chemical means. Membranes are removed after 5-7 months. Since infection was prevented, the implants obtained stability, healthy peri-implant mucosal tissues were observed and missing bone in the alveoli regenerated. Of 21 transmucosal implants placed into fresh extraction sockets, 20 yielded complete bone fill and coverage of the entire plasma-coated implants surface at the time of membrane removal. This documentation suggests that the immediate nonsubmerged installation of an implant into an extraction socket is a predictable treatment modality with good long-term prognosis. PMID:7827230

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

    PubMed Central

    Li, Bei; Wang, Yao

    2014-01-01

    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

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

    PubMed

    Li, Bei; Wang, Yao

    2014-12-01

    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

  14. 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 ...

  15. Ridge Preservation for Implant Therapy: a Review of the Literature

    PubMed Central

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

    2014-01-01

    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

  16. The evolution of tooth wear indices

    PubMed Central

    2008-01-01

    Tooth wear—attrition, erosion and abrasion—is perceived internationally as an ever-increasing problem. Clinical and epidemiological studies, however, are difficult to interpret and compare due to differences in terminology and the large number of indices that have been developed for diagnosing, grading and monitoring dental hard tissue loss. These indices have been designed to identify increasing severity and are usually numerical. Some record lesions on an aetiological basis (e.g. erosion indices), others record lesions irrespective of aetiology (tooth wear indices); none have universal acceptance, complicating the evaluation of the true increase in prevalence reported. This article considers the ideal requirements for an erosion index. It reviews the literature to consider how current indices have evolved and discusses if these indices meet the clinical and research needs of the dental profession. PMID:17701430

  17. The evolution of tooth wear indices

    Microsoft Academic Search

    Penny Fleur Bardsley

    2008-01-01

    Tooth wear—attrition, erosion and abrasion—is perceived internationally as an ever-increasing problem. Clinical and epidemiological\\u000a studies, however, are difficult to interpret and compare due to differences in terminology and the large number of indices\\u000a that have been developed for diagnosing, grading and monitoring dental hard tissue loss. These indices have been designed\\u000a to identify increasing severity and are usually numerical. Some

  18. Postmenopausal Estrogen Replacement and Tooth Retention

    Microsoft Academic Search

    1997-01-01

    PURPOSE To determine if estrogen replacement therapy (ERT) is associated with improved tooth retention and lower risk of edentulism (no natural teeth remaining) in a cohort of elderly women.PATIENTS AND METHODS Subjects were 488 women, aged 72 to 95, who participated in the 23rd examination cycle (1994 to 1995) of the Framingham Heart Study, a population-based study begun in 1948.

  19. Stem cells and tooth tissue engineering

    Microsoft Academic Search

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

    2008-01-01

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

  20. Bivalent histone modifications during tooth development.

    PubMed

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

    2014-12-01

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

  1. Microsystems Technology for Retinal Implants

    NASA Astrophysics Data System (ADS)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  2. Iatrogenic traumatic brain injury during tooth extraction.

    PubMed

    Troxel, Mark

    2015-01-01

    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

  3. Implants in partially edentulous patients. A longitudinal study of bridges supported by both implants and natural teeth.

    PubMed

    Gunne, J; Astrand, P; Ahlén, K; Borg, K; Olsson, M

    1992-06-01

    The aim of the study was to compare the outcome of bridges supported by implants with bridges supported by a combination of implants and natural teeth abutments. The study comprised 23 patients with Applegate Kennedy Class I dentition in the mandible and a full upper denture. Implants ad modum Brånemark were inserted in the posterior areas of both mandibular quadrants. On one side, a bridge supported by 2 implants was constructed (Type I) and on the other side, a bridge supported by 1 tooth (mostly the canine or first premolar) and 1 implant was made (Type II). A total of 46 bridges were made and during the 3-year follow-up period, 4 Type I and 2 Type II bridges were lost. 8 out of 69 implants were lost during the 3-year follow-up, resulting in an implant survival rate of 88.4%. Marginal bone loss, one of several parameters, was evaluated on standardized intraoral radiographs. This was performed during the 1st and 2nd year of function and the total mean bone loss from loading was 0.46 mm and 0.56 mm, respectively. The bone loss during the 2nd year of function was significantly less, adjacent to implants supporting Type II bridges, than adjacent to implants supporting Type I bridges. Summarily, no disadvantages of combining of teeth and implants in the same bridge were found in this study. On the contrary, the slightly lower marginal bone loss adjacent to implants in Type II bridges may indicate that the bone reactions could be more favorable when bridges are connected to both implants and teeth. PMID:15900668

  4. Influence of tooth profile modification on spur gear dynamic tooth strain

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Townsend, Dennis P.

    1995-01-01

    This paper presents results of dynamic strain gage measurements performed on the NASA gear-noise rig. The experiments were part of a joint research program between NASA and the U.S. Army Research Laboratory to advance the technology of rotorcraft transmissions. Tests were performed on six sets of low contact ratio spur gears with different tooth profile modifications. Results presented include static and dynamic measurements of gear tooth strain taken over a matrix of operating conditions. The results demonstrate that a well-designed tooth profile modification can significantly reduce dynamic loads in spur gears, especially for gears which operate at high speed and under high torque. The two parabolic modifications tested were not as effective as linear modifications, possibly because the modification zone was too long.

  5. Neurovascular disturbances after implant surgery.

    PubMed

    Jacobs, Reinhilde; Quirynen, Marc; Bornstein, Michael M

    2014-10-01

    With a steadily increasing impact of oral implant placement in daily practice, the number of reported surgical complications has also been growing. Recent studies reveal significant variation in the occurrence and morphology of neurovascular canal structures in the jaw bone. All those structures contain a neurovascular bundle, the diameter of which may be large enough to cause clinically significant damage. Therefore, it has become obvious that presurgical radiographic planning of jaw-bone surgery should pay attention to the neurovascular structures and their likely variations, in addition to examining many other factors, such as jaw-bone morphology and volume, bone trabecular structure and the absence of bone or tooth pathology. A critical review is accomplished to explore the potential risks for neurovascular complications after implant placement, with evidence derived from histologic, anatomic, clinical and radiologic studies. In this respect, cross-sectional imaging can often be advocated, as it is obvious that the inherent three-dimensional nature of jaw-bone anatomy may clearly benefit from a detailed spatial image analysis. Although this could initially be realized by conventional computed tomography, in current practice, dentomaxillofacial cone beam computed tomography might be used, as it offers high-quality images at low radiation dose levels and costs. PMID:25123768

  6. Tooth structural health monitoring with a fiber optic microbend sensor

    NASA Astrophysics Data System (ADS)

    Kishen, A.; Rafique, A.

    2006-02-01

    The purpose of this study is to monitor structural response in intact teeth and teeth with structural loss using a noninvasive fiber optic microbend (FOMB) sensor. In this study a miniature fiber optic microbend sensor is fabricated and tested on intact tooth specimens, tooth specimens in which one-third crown structure was removed, tooth specimens in which access cavity was prepared and tooth specimens in which access cavity and root canal were prepared. The microbend sensor displayed a direct relationship between the applied load and the output light intensity. The rate of change in light intensity with increase in loads corresponded with the structural response of the tooth. This experiment highlights the potential of FOMB sensor technology to quantitatively monitor tooth structural loss during post endodontic restorations.

  7. Efficacy of nonthermal atmospheric pressure plasma for tooth bleaching.

    PubMed

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

    2015-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    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.

  9. Insights on Metal Based Dental Implants and their Interaction with the Surrounding Tissues.

    PubMed

    Popa, Marcela; Hussien, Mohamed D; Cirstea, Alexandra; Grigore, Raluca; Lazar, Veronica; Bezirtzoglou, Eugenia; Chifiriuc, Mariana Carmen; Sakizlian, Monica; Stavropoulou, Elisavet; Bertesteanu, Serban

    2015-01-01

    At present, the use of dental implants is a very common practice as tooth loss is a frequent problem and can occur as a result of disease or trauma. An implant is usually made of biocompatible materials that do not cause rejection reactions and allow the implant union with the respective bone. To achieve this goal, the implant surface may have different structures and coatings, generally used to increase the adherence of the implant to the bone and to decrease the risk of the periimplantar inflammatory reactions. This review gives some insights of the metal based materials used for dental implants, their limits, improvement strategies as well as the pathophysiology, diagnosis, treatment and prevention of periimplantary diseases. PMID:25877088

  10. Mössbauer study of Fe in GaAs following 57 Mn ?+? implantation

    Microsoft Academic Search

    K. Bharuth-Ram; H. P. Gunnlaugsson; G. Weyer; R. Mantovan; D. Naidoo; R. Sielemann; M. Fanciulli; G. Langouche; S. Olafsson; Th. Aigne

    2009-01-01

    Mössbauer measurements have been performed on a GaAs single crystal sample following the implantation of radioactive 57Mn?+? ( min) ions. The Mn?+? ions were implanted with 60 keV energy into a GaAs sample held at temperatures of 300–700 K in an implantation chamber. Implantation\\u000a fluences were 12 ions\\/cm2 which assured single ion implantations. Mössbauer spectra were measured with a resonance detector equipped with

  11. 21 CFR 872.5525 - Preformed tooth positioner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...5525 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5525 Preformed tooth positioner. (a)...

  12. 21 CFR 872.5525 - Preformed tooth positioner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...5525 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5525 Preformed tooth positioner. (a)...

  13. Interactions of the tooth and bone during development.

    PubMed

    Alfaqeeh, S A; Gaete, M; Tucker, A S

    2013-12-01

    The tooth works as a functional unit with its surrounding bony socket, the alveolar bone. The growth of the tooth and alveolar bone is co-ordinated so that a studied distance always separates the 2, known as the tooth-bone interface (TBI). Lack of mineralization, a crucial feature of the TBI, creates the space for the developing tooth to grow and the soft tissues of the periodontium to develop. We have investigated the interactions between the tooth and its surrounding bone during development, focusing on the impact of the developing alveolar bone on the development of the mouse first molar (M1). During development, TRAP-positive osteoclasts are found to line the TBI as bone starts to be deposited around the tooth, removing the bone as the tooth expands. An enhancement of osteoclastogenesis through RANK-RANKL signaling results in an expansion of the TBI, showing that osteoclasts are essential for defining the size of this region. Isolation of the M1 from the surrounding mesenchyme and alveolar bone leads to an expansion of the tooth germ, driven by increased proliferation, indicating that, during normal development, the growth of the tooth germ is constrained by the surrounding tissues. PMID:24155263

  14. A panorama of tooth wear during the medieval period.

    PubMed

    Esclassan, Rémi; Hadjouis, Djillali; Donat, Richard; Passarrius, Olivier; Maret, Delphine; Vaysse, Frédéric; Crubézy, Eric

    2015-01-01

    Tooth wear is a natural phenomenon and a universal occurrence that has existed from the origin of humankind and depends on the way of life, especially diet. Tooth wear was very serious in ancient populations up to the medieval period. The aim of this paper is to present a global view of tooth wear in medieval times in Europe through different parameters: scoring systems, quantity and direction of wear, gender, differences between maxilla and mandible, relations with diet, caries, tooth malpositions and age. PMID:25807388

  15. Implantable cardioverter\\/defibrillator therapy in arrhythmogenic right ventricular cardiomyopathy. Single-center experience of long-term follow-up and complications in 60 patients

    Microsoft Academic Search

    Thomas Wichter; Matthias Paul; Christian Wollmann

    2004-01-01

    Background—Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of ventricular tachycardia (VT) and cardiac arrest in young patients. We hypothesized that treatment with implantable cardioverter\\/defibrillators (ICDs) is safe and improves the long-term prognosis of ARVC patients at high risk of sudden death. Methods and Results—Sixty patients with ARVC (aged 4316 years) were treated with transvenous ICD systems. Despite a

  16. Catheter Ablation for the Treatment of Electrical Storm in Patients With Implantable Cardioverter-Defibrillators Short and Long-Term Outcomes in a Prospective Single-Center Study

    Microsoft Academic Search

    Corrado Carbucicchio; Matteo Santamaria; Nicola Trevisi; Giuseppe Maccabelli; Francesco Giraldi; Gaetano Fassini; Stefania Riva; Massimo Moltrasio; Manuela Cireddu; Fabrizio Veglia; Paolo Della Bella

    2010-01-01

    Background—Electrical storm (ES) caused by recurrent episodes of ventricular tachycardia (VT) can cause sudden death in patients with implantable cardioverter-defibrillators and adversely affects prognosis in survivors. Catheter ablation has been proposed for treating ES, but its long-term effect in a large population has never been verified. Methods and Results—Ninety-five consecutive patients with coronary artery disease (72 patients), idiopathic dilated cardiomyopathy

  17. Auditory Midbrain Implant: A Review

    PubMed Central

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

    2009-01-01

    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

  18. Magnesium stable isotope ecology using mammal tooth enamel

    PubMed Central

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

    2015-01-01

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (?13C) 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 (?44Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (?26Mg) 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 ?26Mg, ?13C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that ?26Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this 26Mg enrichment up the trophic chain is due to a 26Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using ?26Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel ?26Mg 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

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

    PubMed

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

    2006-01-01

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

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

    PubMed Central

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

    2006-01-01

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

  1. The expandable mammary implant.

    PubMed

    Becker, H

    1987-04-01

    An expandable saline-gel implant having a detachable injection dome is described. The implant functions initially as a tissue expander. Once the correct size has been obtained, the injection dome is removed, leaving the implant in position. PMID:3823256

  2. Cochlear implants in young children.

    PubMed

    Niparko, John K; Blankenhorn, Rebecca

    2003-01-01

    The cochlear implant is best characterized as a device that provides access to the sound environment. The device enables the hearing pathway to respond to environmental and speech sounds, providing informational cues from the surroundings and from others that may escape visual detection. As the developmental effects of a profound hearing loss are multiple, cochlear implants have been applied to ever younger children in an attempt to promote a more normal level of developmental learning through audition. In deafness, transducer elements of the inner ear fail to trigger auditory nerve afferent nerves in the presence of sound input. However, large reserves of afferent fibers exist even in the auditory nerve of a profoundly deaf patient. Furthermore, these nerve fibers retain the ability to respond to prosthetic activation. Through developmental learning in the early, formative years, auditory centers of the brain appear capable of processing information from the implant to provide speech comprehension and oral language development. Multichannel implants have replaced original single channel designs. multichannel devices enable larger percentages of recipients to recognize the spoken word without visual cues because they provide spectral information in addition to temporal and intensity cues. Testing under conditions of auditory (implant)-only input reveals significant open-set speech understanding capabilities in more than 75% of children after three years of device use. The benefit provided by implants may vary with a number of conditions including: hearing history, age of deafness onset, age at implantation, etiology of deafness, linguistic abilities, and the presence of a motivated system of support of oral language development. Patient variables should be given individual consideration in judging candidacy for a cochlear implant and in planning rehabilitative and education services after surgery and activation of the device. PMID:14648819

  3. Implant bone integration importance in forensic identification.

    PubMed

    De Angelis, Danilo; Cattaneo, Cristina

    2015-03-01

    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

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

    PubMed

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

    2015-01-01

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

  5. Simulated Single Tooth Bending of High Temperature Alloys

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert, F.; Burke, Christopher

    2012-01-01

    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.

  6. CHIPPING FRACTURE RESISTANCE OF DENTURE TOOTH MATERIALS

    PubMed Central

    Quinn, G. D.; Giuseppetti, A. A.; Hoffman, K. H.

    2014-01-01

    Objective The applicability of the edge chipping method to denture tooth materials was assessed. These are softer materials than those usually tested by edge chipping. The edge chipping fracture resistances of polymethylmethacrylate (PMMA) based and two filled resin composite denture tooth materials were compared. Methods An edge chipping machine was used to chip rectangular blocks and flattened anterior denture teeth. Force versus edge distance data were collected over a broad range of forces and distances. Between 20 and 65 chips were made per condition depending upon the material, the scatter, and the indenter type. Different indenter types were used including Rockwell C, sharp conical 120°, Knoop, and Vickers. The edge toughness, Te, was evaluated for different indenter types. Results The edge chipping data collected on the blocks matched the data collected from flattened teeth. High scatter, particularly at large distances and loads, meant that many tests (up to 64) were necessary to compare the denture tooth materials and to ascertain the appropriate data trends. A linear force – distance trend analysis was adequate for comparing these materials. A power law trend might be more appropriate, but the large scatter obscured the definitive determination of the precise trend. Different indenters produce different linear trends, with the ranking of: sharp conical 120°, Rockwell C, and Knoop, from lowest to highest edge toughness. Vickers indenter data were extremely scattered and a sensible trend could not be obtained. Edge toughness was inversely correlated to hardness. Significance Edge chipping data collected either from simple laboratory scale test blocks or from actual denture teeth may be used to evaluate denture materials. The edge chipping method’s applicability has been extended to another class of restorative materials. PMID:24674342

  7. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  8. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  9. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

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

    PubMed

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

    2013-03-01

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

  11. Common developmental pathways link tooth shape to regeneration

    PubMed Central

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

    2013-01-01

    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

  12. On the use of EMI for the assessment of dental implant stability

    NASA Astrophysics Data System (ADS)

    La Malfa Ribolla, Emma; Rizzo, Piervincenzo; Gulizzi, Vincenzo

    2014-03-01

    The achievement and the maintenance of dental implant stability are prerequisites for the long-term success of the osseointegration process. Since implant stability occurs at different stages, it is clinically required to monitor an implant over time, i.e. between the surgery and the placement of the artificial tooth. In this framework, non-invasive tests able to assess the degree of osseointegration are necessary. In this paper, the electromechanical impedance (EMI) method is proposed to monitor the stability of dental implants. A 3D finite element model of a piezoceramic transducer (PZT) bonded to a dental implant placed into the bone was created, considering the presence of a bone-implant interface subjected to Young's modulus change. The numerical model was validated experimentally by testing bovine bone samples. The EMI response of a PZT, bonded to the abutment screwed to implants inserted to the bone, was measured. To simulate the osseointegration process a pulp canal sealer was used to secure the implant to the bone. It was found that the PZT's admittance is sensitive to the stiffness variation of the bone-implant interface. The results show that EMIbased method is able (i) to evaluate the material properties around the implant, and (ii) to promote a novel non-invasive monitoring of dental implant surgical procedure.

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

    PubMed Central

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

    2013-01-01

    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

  14. An Analysis of the Symptomatic Domains Most Relevant to Charcot Marie Tooth Neuropathy (CMT) Patients

    ClinicalTrials.gov

    2015-04-28

    Charcot Marie Tooth Disease (CMT); Hereditary Sensory and Motor Neuropathy; Nerve Compression Syndromes; Tooth Diseases; Congenital Abnormalities; Genetic Diseases, Inborn; Heredodegenerative Disorders, Nervous System

  15. Spatial and temporal events in tooth development of Astyanax mexicanus.

    PubMed

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

    2014-11-01

    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

  16. Air dissipation in saline breast implants.

    PubMed

    Schanzer, Andres; Wong, Granger B

    2002-06-01

    Residual air within saline breast implants can cause patient discomfort due to the mechanical and auditory effects of sloshing. Small amounts of air have no clinical significance, but if larger quantities are present and audible, the patient is reassured that the implant shell is gas-permeable and that the air will dissipate/diffuse. This study examined the time necessary for air dissipation in saline breast implants.Twelve McGhan style #68 saline breast implants were divided into two groups: group A, which included six implants with a size of 240 cc, and group B, which included six implants with a size of 270 cc. The implants were filled with room-temperature, intravenous, normal saline to their designated volumes, plus 30 cc of overfill. All air was evacuated, and each implant was inoculated with 5 cc of air. The implants were then submerged in a single tank of normal saline at 37 degrees C, at a depth of 20.4 cm to replicate capillary pressure. Intragroup analysis showed the air bubble was absent in group A at an average of 35.3 days (variance = 4.13) and in group B at an average of 38.0 days (variance = 0). If audible intraluminal air is present in the clinical setting, the patient can be reassured that the problem will resolve in approximately 30 days or less. PMID:12045543

  17. Immediate implants at fresh extraction sockets: from myth to reality.

    PubMed

    Vignoletti, Fabio; Sanz, Mariano

    2014-10-01

    In recent years, immediate implant placement has become a common clinical therapeutic protocol representing an alternative to the classical delayed surgical protocol of implant placement. This protocol, however, has not been fully validated, either in terms of fully understanding the influence of implant placement on the socket-healing process or on the clinical outcomes. This narrative review evaluates the different experimental studies in humans and animals assessing the bone-healing dynamics of the socket after tooth extraction and the dimensional changes occurring at the socket bone walls. These experimental studies describe, in detail, the hard- and soft-tissue healing of implants placed into fresh extraction sockets, demonstrating that marked morphological changes of the alveolar ridge will occur, independently of the implant installation, thus demonstrating that postextraction bone loss is an inevitable biological process. This evidence has also been corroborated in clinical studies in humans, demonstrating the risk of significant peri-implant tissue loss, mainly in the areas of high esthetic demand. There is a lack of long-term evidence on the impact of this protocol on the preservation of the peri-implant tissues. In conclusion, despite the obvious advantages of this surgical protocol, it also has limitations and is more technically demanding than placing an implant into a healed crest. When selecting this protocol, clinicians should always consider: (a) the gingival biotype of the patient; (b) the thickness and integrity of the socket bony walls; (c) the implant selection as well as the adequate vertical and horizontal position of the implant; and (d) the ideal patient (a nonsmoker with good plaque control). PMID:25123766

  18. JUNCTION FORMATION AND ITS DEVICE IMPAC TT HROUGH THE NODES: FROM SINGLE T OC O-IMPLANTS, FROM BEAM-LINE TO PLASMA, FROM SINGLE IONS T OC LUSTERS, FROM RTA T OL TP

    Microsoft Academic Search

    Hans-Joachim L. Gossmann

    The fundamental design goals for a high-perf or mance logic technology ,m aximizing speed while minimizing power, d rive t he design of the junctions and in tur nt he require- ments on dopant placement and activation. In the early nodes implant energies of 10's ke Va nd furnace anneals sufficed. Scaling into the deep-sub-micron regime brought Tr a nsient

  19. Adhesion of denture tooth porcelain to heat-polymerized denture resin.

    PubMed

    Marchack, B W; Yu, Z; Zhao, X Y; White, S N

    1995-09-01

    Use of porcelain denture teeth may be desirable in many clinical situations, including implant-supported prostheses. However, lack of space because of frameworks often precludes the use of conventional retention by diatorics and pins. Adhesion of porcelain denture teeth to denture resin could also stiffen and possibly strengthen dentures and decrease stain ingress between porcelain teeth and resin denture bases. Unlike previous studies that investigated the bond between conventional feldspathic metal-ceramic porcelain and bis-GMA based composite resin, this study investigated adhesion of denture tooth porcelain to polymethyl methacrylate (PMMA). High-energy air abrasion, hydrofluoric acid etching, and the use of a general purpose bonding agent resulted in an improved bond strength of heat-cured denture PMMA bonded to denture tooth porcelain. Silane coating did not improve bond strengths, and conventional air abrasion was no more effective than polishing with 600-grit silicon carbide. Storage in water and artificial aging substantially decreased bond strengths. The strongest bond strengths were achieved by a high-energy-abrasion + etching + multi-purpose bonding-agent treatment, but a simpler etching + multiple-purpose bonding-agent treatment also produced reliable results. A laboratory technique was suggested. The role of surface treatment in the mechanism of adhesion was examined with scanning electron microscopy. High-energy abrasion produced a slightly more detailed initial topography than conventional air abrasion, but after etching, the high-energy topography became much more detailed. Surface topography alone did not account for all differences found. PMID:7473277

  20. Prevention of Streptococcus mutans infection of tooth surfaces by salivary antibody in Irus monkeys (Macaca fascicularis).

    PubMed Central

    Evans, R T; Emmings, F G; Genco, R J

    1975-01-01

    Four irus monkeys (Macaca fascicularis) were immunized with Streptococcus mutans 6715 killed cells and cell products by injection in the vicinity of the major salivary glands and by instillation into the parotid glands via the ducts. After immune group and a sham-immunized control group of monkeys were infected orally with viable strain 6715 organisms. Dental plaque samples were taken at intervals from the buccal and lingual grooves of the first permanent molars. These samples were evaluated for recovery of strain 6715 by cultural methods. In addition, individual samples were taken from 10 representative tooth surfaces and were evaluated by indirect immunofluorescent staining for strain 6715. Results showed that immune monkeys had fewer infected surfaces and fewer organisms on the infected surfaces than the control animals. These studies indicate that salivary antibody to cariogenic streptococci inhibits implantation of these organisms in dental plaque and may be protective against dental caries. PMID:1097337

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

    PubMed Central

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

    2015-01-01

    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

  2. Space Maintainers for Premature Tooth Loss

    MedlinePLUS

    ... into adulthood. After that, the child can receive dental implants or a bridge or continue to use a ... band is also removed and sent to the dental laboratory with the impressions. The lab creates ... or removable partial denture in the space. Last ...

  3. A Combined Approach for the Treatment of Resorbed Fresh Sockets Allowing Immediate Implant Restoration. A 2-Year Follow-Up.

    PubMed

    de Molon, Rafael Scaf; Avila, Erica Dorigatti; Cirelli, Joni Augusto; Mollo-Jr, Francisco de Assis; Andrade, Marcelo Ferrarezi; Barros-Filho, Luiz Antonio Borelli; Barros, Luiz Antonio Borelli

    2013-12-18

    Abstract Introduction: The demand for optimal esthetics has increased with the advance of the implant dentistry and with the desire for easier, safer and faster technique allowing predictable outcomes. Thus, the aim of this case report was to describe a combined approach for the treatment of a periodontally compromised tooth by means of atraumatic tooth extraction, immediate flapless implant placement, autogenous block and particulate bone graft followed by connective tissue graft and immediate provisionalization of the crown in the same operatory time. Case Report: A 27-year-old woman underwent the proposed surgical procedures for the treatment of her compromised maxillary right first premolar. The tooth was removed atraumatically with a periotome without incision. A dental implant was inserted 3 mm apical to the cement-enamel junction of the adjacent teeth enabling the ideal tridimensional implant position. An osteotomy was performed in the maxillary tuber for block bone graft harvesting that allowed the reconstruction of the alveolar buccal plate. Thereafter, an autogenous connective tissue graft was placed to increase both the horizontal and vertical dimensions of the alveolar socket reaching the patient functional and esthetic expectations. Conclusion: This treatment protocol was efficient to create a harmonious gingival architecture with sufficient width and thickness, maintaining the stability of the alveolar bone crest yielding excellent aesthetic results after 2-years of follow-up. We suggest that this approach can be considered a viable alternative for the treatment of periodontally compromised tooth in the maxillary esthetic area enhancing patient comfort and satisfaction. PMID:24351101

  4. Endodontic Treatment of an Anomalous Anterior Tooth with the Aid of a 3-dimensional Printed Physical Tooth Model.

    PubMed

    Byun, Chanhee; Kim, Changhwan; Cho, Seungryong; Baek, Seung Hoon; Kim, Gyutae; Kim, Sahng G; Kim, Sun-Young

    2015-06-01

    Endodontic treatment of tooth formation anomalies is a challenge to clinicians and as such requires a complete understanding of the aberrant root canal anatomy followed by careful root canal disinfection and obturation. Here, we report the use of a 3-dimensional (3D) printed physical tooth model including internal root canal structures for the endodontic treatment of a challenging tooth anomaly. A 12-year-old boy was referred for endodontic treatment of tooth #8. The tooth showed class II mobility with swelling and a sinus tract in the buccal mucosa and periapical radiolucency. The tooth presented a very narrow structure between the crown and root by distal concavity and a severely dilacerated root. Moreover, a perforation site with bleeding and another ditching site were identified around the cervical area in the access cavity. A translucent physical tooth model carrying the information on internal root canal structures was built through a 3-step process: data acquisition by cone-beam computed tomographic scanning, virtual modeling by image processing, and manufacturing by 3D printing. A custom-made guide jig was then fabricated to achieve a safe and precise working path to the root canal. Endodontic procedures including access cavity preparation were performed using the physical tooth model and the guide jig. At the 7-month follow-up, the endodontically treated tooth showed complete periapical healing with no clinical signs and symptoms. This case report describes a novel method of endodontic treatment of an anomalous maxillary central incisor with the aid of a physical tooth model and a custom-made guide jig via 3D printing technique. PMID:25732403

  5. Surface modification of sapphire by ion implantation

    SciTech Connect

    McHargue, C.J.

    1998-11-01

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

  6. Effects of CaCl2 hydrothermal treatment of titanium implant surfaces on early epithelial sealing.

    PubMed

    Oshiro, Wakana; Ayukawa, Yasunori; Atsuta, Ikiru; Furuhashi, Akihiro; Yamazoe, Jyunichi; Kondo, Ryosuke; Sakaguchi, Mami; Matsuura, Yuri; Tsukiyama, Yoshihiro; Koyano, Kiyoshi

    2015-07-01

    Improvement of oral epithelial adhesion to titanium (Ti) may significantly enhance the efficacy of dental implants. We aimed to investigate whether calcium chloride (CaCl2) hydrothermally treated (HT) Ti could promote sealing of the peri-implant epithelium (PIE) around the implant. Right maxillary first molars were extracted from rats and replaced with either CaCl2-HT implants (Ca-HT group), distilled water-HT implants (DW-HT group), or untreated implants (Cont group). After 4 weeks, the implant-PIE interface of the Ca-HT group exhibited a band of immunoreactive laminin-332, similar to the tooth-junctional epithelium interface, which was absent in the Cont and DW-HT groups at the upper portion. We also investigated the effect of Ca-HT on the attachment of rat oral epithelial cells (OECs). OEC adherence onto Ca-HT Ti plates was stronger with higher expression levels of adhesion proteins compared with Cont and DW-HT groups. These results indicate that HT with CaCl2 improves the integration of soft tissue cells with the Ti implant at 4 weeks after implantation, which might facilitate the development of a soft tissue barrier around the implant. PMID:25982317

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

    PubMed Central

    Consolaro, Alberto; Romano, Fábio Lourenço

    2014-01-01

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

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

    PubMed

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

    2013-01-01

    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

  9. Tooth retention, tooth loss and use of dental care among long-term narcotics abusers.

    PubMed

    Fan, Jing; Hser, Yih-Ing; Herbeck, Diane

    2006-06-01

    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 the oral examination and survey of use of dental services. African American addicts showed the least number of remaining teeth; and African Americans and Hispanics were less likely to utilize dental services compare to Whites. Factors significantly related to tooth retention were abusers' age (p = 0.0006), ethnicity (p = 0.01), income (p < 0.0001), smoking status (p = 0.03), and dental visits during the 12 months prior to the survey (p < 0.0001). These findings suggest that settings such as prisons and drug treatment programs that include dental care referral and follow-up would be expected to enhance oral and general health among narcotics-addicted individuals. PMID:17062542

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

    PubMed

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

    2011-01-01

    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

  11. Industrial Noise and Tooth Wear - Experimental Study

    PubMed Central

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

    2015-01-01

    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

  12. Functional constraints on tooth morphology in carnivorous mammals

    PubMed Central

    2012-01-01

    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

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

    PubMed Central

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

    2012-01-01

    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

  14. Assessment of tooth structure using an alternative electrical bioimpedance spectroscopy method.

    PubMed

    Morais, Andréa Pereira; Pino, Alexandre Visintainer; Souza, Marcio Nogueira

    2014-01-01

    In the past few years bioimpedance has been used in many applications in dentistry, such as estimating the length of root canals and the physical properties of enamel. Despite the significant number of studies using bioimpedance to investigate the dental structure, many of them use only the real component of bioimpedance, i.e., the resistance, disregarding the information provided by the imaginary one, i.e., the reactance. Moreover, in different studies that investigate both parts of bioimpedance, the data are obtained by using single frequency or multifrequency methods based on sinusoidal sweep. The aim of this study was to investigate the use of an alternative bioimpedance spectroscopy (BIS) method based on step response in the assessment of tooth structure. To test the feasibility of the studied method we performed in vitro experiments that considered the successive removal of enamel layers of 22 healthy teeth, the accomplishment of the BIS method, and the estimate of bioimpedance parameter that were associated with the changes in the tooth structure. To deal with the variability of bioimpedance parameters a dental health index (DHI) is proposed. The findings include the behavior of bioimpedance parameters of intact teeth, as well as those associated with the successive removal of the enamel layer, and indicate that DHI is sensitive enough to detect changes of the enamel layer. The results point to the feasibility of the studied BIS method in evaluating tooth structure and that it might be used to assess dental health. PMID:25140720

  15. Natal Tooth Associated with Fibrous Hyperplasia – A Rare Case Report

    PubMed Central

    Munjal, Deepti; Dhingra, Renuka; Malik, Narender Singh; Sidhu, Gagandeep Kaur

    2015-01-01

    Eruption of tooth at about 6 months of age is a significant stage in child’s life and is an emotional event for parents. However, a tooth present in the oral cavity of newborn can lead to a lot of delusions. Natal and neonatal teeth are of utmost importance not only for a dentist but also for a paediatrician due to parent’s anxiety, folklore superstitions and numerous associated complications with it. This paper reports a rare case, wherein a natal tooth has led to the development of a reactive fibrous hyperplasia in an 8-week-old infant. PMID:26023656

  16. Natal tooth associated with fibrous hyperplasia - a rare case report.

    PubMed

    Sethi, Harsimran Singh; Munjal, Deepti; Dhingra, Renuka; Malik, Narender Singh; Sidhu, Gagandeep Kaur

    2015-04-01

    Eruption of tooth at about 6 months of age is a significant stage in child's life and is an emotional event for parents. However, a tooth present in the oral cavity of newborn can lead to a lot of delusions. Natal and neonatal teeth are of utmost importance not only for a dentist but also for a paediatrician due to parent's anxiety, folklore superstitions and numerous associated complications with it. This paper reports a rare case, wherein a natal tooth has led to the development of a reactive fibrous hyperplasia in an 8-week-old infant. PMID:26023656

  17. Unique case of a geminated supernumerary tooth with trifid crown

    PubMed Central

    Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi

    2012-01-01

    Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper. PMID:23071971

  18. Decelerating and sex-dependent tooth wear in Norwegian red deer

    Microsoft Academic Search

    Leif Egil Loe; Atle Mysterud; Rolf Langvatn; Nils Chr. Stenseth

    2003-01-01

    In ungulates, tooth wear is often suggested as a proximate cause of senescence. Tooth wear is expected to be sex-dependent since energetic requirements and food selection varies largely between sexes in sexually dimorphic ungulates. Furthermore, tooth wear may lower mastication efficiency, and we predict a negative correlation between tooth wear and body weight or condition. We tested these predictions on

  19. Determination of the ISO tooth form factor for involute spur and helical gears

    Microsoft Academic Search

    J. I. Pedrero; A. Rueda; A. Fuentes

    1999-01-01

    To estimate the bending stress at the root of a loaded gear tooth, ISO\\/TC-60 introduced the tooth form factor and the stress concentration factor, which were both defined as a function of the tooth thickness at the critical section and the distance between this section and the intersection of the line of action and the tooth centerline, when load acts

  20. Performance of collagen sponge as a 3-D scaffold for tooth-tissue engineering

    Microsoft Academic Search

    Yoshinori Sumita; Masaki J. Honda; Takayuki Ohara; Shuhei Tsuchiya; Hiroshi Sagara; Hideaki Kagami; Minoru Ueda

    2006-01-01

    Tooth structure can be regenerated by seeding dissociated tooth cells onto polyglycolic acid fiber mesh, although the success rate of tooth production is low. The present study was designed to compare the performance of collagen sponge with polyglycolic acid fiber mesh as a 3-D scaffold for tooth-tissue engineering. Porcine third molar teeth at the early stage of crown formation were

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

    PubMed

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

    2014-01-01

    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

  2. Ion-implantation doping of silicon carbide

    SciTech Connect

    Gardner, J.; Edwards, A.; Rao, M.V. [George Mason Univ., Fairfax, VA (United States); Papanicolaou, N.; Kelner, G. [Naval Research Lab., Washington, DC (United States); Holland, O.W. [Oak Ridge National Lab., TN (United States)

    1997-10-01

    Because of their commercial availability in bulk single crystal form, the 6H- and 4H- polytypes of SiC are gaining importance for high-power, high-temperature, and high-frequency device applications. Selective area doping is a crucial processing step in integrated circuit manufacturing. In Si technology, selective area doping is accomplished by thermal diffusion or ion-implantation. Because of the low diffusion coefficients of most impurities in SiC, ion implantation is indispensable in SiC device manufacturing. In this paper the authors present their results on donor, acceptor, and compensation implants in 6H-SiC.

  3. Cochlear implant placement: round window approach.

    PubMed

    Backous, Douglas D

    2014-01-01

    The indications for cochlear implantation continue to extend to patients with increased levels of residual hearing. Single-sided deafness and tinnitus are currently under various clinical trials as even further expansion of the application of cochlear implant device and programming technology is underway. This video details a round window and hearing preservation approach for cochlear implant placement, and incorporates the most recent advances in surgical technique. The video can be found here: http://youtu.be/bDqkbboXrU4 . PMID:24380531

  4. Expanded selection criteria in adult cochlear implantation.

    PubMed

    Arnoldner, Christoph; Lin, Vincent Y W

    2013-11-01

    Cochlear implantation has become the standard procedure for restoring substantial hearing in the profoundly deaf. The excellent performance of most of the CI recipients coupled with the rapid evolution of implant technology lead to a distinct expansion in selection criteria for CI. These changes in candidacy primarily include patients with (1) moderate preoperative speech recognition with hearing aids, (2) significant residual hearing, (3) single-sided deafness, and (4) geriatric patients. Many of these patients' conditions were regarded as a clear contraindication to CI only a few years ago. In this article an overview of the current and new aspects of candidacy for cochlear implantation is provided. PMID:24533755

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

    NASA Technical Reports Server (NTRS)

    Sun, D. C.; Yuan, Qin

    1995-01-01

    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.

  6. Accuracy of 3D scanners in tooth mark analysis.

    PubMed

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

    2015-01-01

    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

  7. Implant supported dentures and masticatory performance

    Microsoft Academic Search

    Bjarni E. Pjetursson

    2008-01-01

    Data SourcesMedline, Cochrane LibraryStudy SelectionEnglish articles published from 1966 to June 2007, in which the masticatory performance of subjects with implant-supported or retained dentures was assessed by objective methods and compared to performance with conventional dentures, were included. Single-toth implants studies were excluded.Data Extraction and SynthesisCharacteristics of subjects, type of dentures, and quantitative results were extracted from original articles. Level

  8. Two Mathematical Models for Generation of Crowned Tooth Surface

    PubMed Central

    Kelemen, Laszlo; Szente, Jozsef

    2014-01-01

    Gear couplings are mechanical components to connect shaft ends and eliminate the misalignments. The most important element of the gear coupling is the hub which is an external gear having crowned teeth. The crowned teeth on the hub are typically produced by hobbing. The resulting tooth surface depends on several parameters. It is influenced by the size of the hob and the feed. In this paper two mathematical models of the crowned tooth surface are introduced for the generation of the idealized tooth surfaces. These are the profile-shifting and the two-parameter enveloping methods. Our aim is to compare the obtained crowned tooth profiles for the two examined models and to investigate the results. From our numerical results, it was found that the two profiles show indistinguishable differences. PMID:24578653

  9. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...3580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a)...

  10. 21 CFR 872.3580 - Preformed gold denture tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...3580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a)...

  11. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...3590 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a)...

  12. 21 CFR 872.3590 - Preformed plastic denture tooth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...3590 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3590 Preformed plastic denture tooth. (a)...

  13. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3200 Food and Drugs 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....

  14. Drugs influencing orthodontic tooth movement: An overall review.

    PubMed

    Diravidamani, Kamatchi; Sivalingam, Sathesh Kumar; Agarwal, Vivek

    2012-08-01

    Orthodontic treatment is based on the premise that when force is delivered to a tooth and thereby transmitted to the adjacent investing tissues, certain mechanical, chemical, and cellular events take place within these tissues, which allow for structural alterations and contribute to the movement of that tooth. Molecules present in drugs and nutrients consumed regularly by patients can reach the mechanically stressed paradental tissues through the circulation and interact with local target cells. The combined effect of mechanical forces and one or more of these agents may be inhibitory, additive, or synergistic. Current orthodontic research aims to develop methods of increasing the tissue concentration of molecules promoting tooth movement, while simultaneously decreasing the concentration of unwanted elements which can produce harmful side effects. This article discusses in detail the various possible drugs that can bring about alterations in the desired orthodontic tooth movement. PMID:23066275

  15. Evaluation of Steam Turbines Triangular Tooth on Stator Labyrinth Seal

    E-print Network

    Tanvir, Hossain Ahmed

    2012-07-16

    of turbomachinery is attained. Performance parameters such as carryover coefficient, discharge coefficient were evaluated for a see through triangular tooth on stator labyrinth seal. This computational study investigates how flow conditions and seal parameter...

  16. Genetics Home Reference: Charcot-Marie-Tooth disease

    MedlinePLUS

    ... affect life expectancy. Typically, the earliest symptoms of Charcot-Marie-Tooth disease involve balance difficulties, clumsiness, and muscle weakness in the feet. Affected individuals may have foot abnormalities such as high arches (pes cavus), flat ...

  17. Brief communication: interproximal tooth wear: a new observation.

    PubMed

    Kaidonis, J A; Townsend, G C; Richards, L C

    1992-05-01

    Microscopic observations were made of wear on the proximal surfaces of tooth crowns of Australian Aboriginals and whites. Typical wear facets displayed well-defined borders within which vertical or near vertical furrows, ranging from about 0.1 to 0.5 mm in width, were noted. Furrows on the interproximal surface of one tooth seemed to "interdigitate" with those on the proximal surface of the adjacent tooth. These observations are not consistent with the commonly-held view that interproximal tooth wear results from a buccolingual movement of adjacent teeth that maintain contact through mesial migration. Vertical or near vertical movement of teeth, possibly including a tipping action, must be an important factor, although the precise nature of the movement requires further investigation. PMID:1510109

  18. [Biomaterials in cochlear implants].

    PubMed

    Stöver, T; Lenarz, T

    2009-05-01

    Cochlear implants (CI) represent the "gold standard" for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed. PMID:19353453

  19. Long-term, totally implantable central venous access ports connected to a Groshong catheter for chemotherapy of solid tumours: experience from 178 cases using a single type of device.

    PubMed

    Biffi, R; Corrado, F; de Braud, F; de Lucia, F; Scarpa, D; Testori, A; Orsi, F; Bellomi, M; Mauri, S; Aapro, M; Andreoni, B

    1997-07-01

    The aim of this study was to examine the early and late complications rate of central venous access ports connected to the Groshong catheter for long-term chemotherapy delivering. All patients suffering from a neoplastic disease, who required long-term chemotherapy and underwent insertion of implantable ports during a 21-month period (1 October 1994-30 June 1996) were prospectively studied. A single type of port was used, constructed of titanium and silicone rubber (Dome Port, Bard Inc., Salt Lake City, U.S.A), connected to an 8 F silastic Groshong catheter tubing (Bard Inc.). A team of different operators (two general surgeons, one interventional radiologist and four anaesthesiologists) was involved in inserting the port. All devices were placed in the operating room under fluoroscopic control. A central venous access form was filled in by the operator after the procedure and all ports were followed prospectively for device-related and overall complications. Data from the follow-up of these patients were entered in the form and collected in a database. Follow-up continued until the device was removed, the patient died or the study was closed. 178 devices, comprising a total of 32,089 days in situ, were placed in 175 patients. Three patients received a second device after removal of the first. Adequate follow-up was obtained in all cases (median 180 days, range 4-559). 138 devices (77.5%) were still in situ when the study was closed. Early complications included six pneumothoraxes, three arterial punctures and two revisions for port and/or catheter malfunction (overall early complications in 8 patients). Late complications included 3 cases (1.68% of devices) of catheter rupture and embolisation (0.093 episodes/1000 days of use), 2 cases (1.12% of devices) of venous thrombosis (0.062 episodes/1000 days of use), 1 case (0.56% of devices) of pocket infection (0.031 episodes/1000 days of use), and 4 cases (2.24% of devices) of port-related bacteraemias (0.124 episodes/1000 days of use). Infections were caused by coagulase-negative Staphylococcus aureus (4 cases) and Bacillus subtilis (1 case); they required port removal in 3 out of 5 cases. This study represents the largest published series of patients with totally implantable access ports connected to Groshong catheters; this device is a good option for long-term access to central veins and delivery of chemotherapeutic regimens, including continuous intravenous infusions. The low incidence of major complications related to implantation and management of these devices support increased use in oncology patients. PMID:9301441

  20. Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

    NASA Astrophysics Data System (ADS)

    Khan, Rao F. H.

    This thesis deals with advancements made in the field of Electron Paramagnetic Resonance (EPR) for biophysical dosimetry with tooth enamel for accident, emergency and retrospective radiation dose reconstruction. A methodology has been developed to measure retrospective radiation exposures in human tooth enamel. This entails novel sample preparation procedures with minimum mechanical treatment to reduce the preparation induced uncertainties, establish optimum measurement conditions inside the EPR cavity, post process the measured spectrum with functional simulation of dosimetric and other interfering signals, and reconstruct dose. By using this technique, retrospective gamma radiation exposures as low as 80 +/- 30 mGy have been successfully deciphered. The notion of dose modifier was introduced in EPR biodosimetry for low dose measurements. It has been demonstrated that by using the modified zero added dose (MZAD) technique for low radiation exposures, doses in the 100 mGy range can be easily reconstructed in teeth which were previously thought useless for EPR dosimetry. Also the use of a dose modifier makes robust dose reconstruction possible for higher radiation exposures. The EPR dosimetry technique was also developed for tooth samples extracted from rodents, which represent small tooth sizing. EPR doses in the molars, extracted from mice irradiated with whole body exposures, were reassessed and shown to be correct within the experimental uncertainty. The sensitivity of human tooth enamel for neutron irradiation, obtained from the 3 MV McMaster K. N. Van de Graaff accelerator, was also studied. For the first time this work has shown that the neutron sensitivity of the tooth enamel is approximately 1/10th of the equivalent gamma sensitivity. Parametric studies for neutron dose rate and neutron energy within the available range of the accelerator, showed no impact on the sensitivity of the tooth enamel. Therefore, tooth enamel can be used as a dosimeter for both neutrons as well as gamma radiation. We will continue experiments to develop this endpoint as a sensitive accident or emergency tool for our response capabilities.

  1. Assessment of Tooth Proportions in an Aesthetically Acceptable Smile

    PubMed Central

    Reddy, Munish; Raghav, Pradeep; Jain, Shalu; Anjum, Arbab; Misra, Vaibhav; Suri, Ragini

    2015-01-01

    Introduction: Aesthetic facial animation is mostly reported to be due to a close relationship between soft and hard tissue i.e. dynamic smile with appropriate tooth proportions. But variations in tooth size have been seen among various ethnic populations globally. Aim: To evaluate the size and morphology of maxillary anterior teeth, the tooth with maximum variation both mesiodistally and cervicoincisally. Also, the tooth to tooth ratio in percentage of the mean tooth sizes in both genders in patients with aesthetically acceptable smile decided by a panel in North Indian population. Materials and Methods: A total of 100 subjects (50 males and 50 females) were taken and a video clip of their dynamic smile was captured .The smiles were analyzed by a panel and the tooth proportions of the selected attractive smiles were evaluated in both males and females separately. Statistical analysis: Data obtained was subjected to statistical analysis using Microsoft Excel 2007 software; test used was Unpaired t-test and also Mean ± S.D., Variance, Ratio of W/L and its ranges were calculated. Significance is assessed at 5% level of significance. Results: The mesiodistal width and cervicoincisal length of maxillary central incisor was greater compared to lateral incisor and canine in both males and females. There was a statistically significant difference between the width/length ratio of maxillary anterior teeth between males and females.Canine and Lateral incisor showed maximum variation mesio-distally and cervico-incisally. Conclusion: A smile is more pleasing if the visible teeth are in proper morphological proportions. Thus, it relates that teeth play a vital role in increasing the attractiveness of a smile. The mean coronal width/length ratio displayed a more square like tooth form for both males and females. PMID:26023632

  2. Ectopic Supernumerary Tooth in Nasal Septum: A Case Study

    PubMed Central

    Mohebbi, Saleh; Salehi, Oveis; Ebrahimpoor, Sedighe

    2013-01-01

    Introduction: Nasal teeth eruption is a rare phenomenon. The variability of symptoms and generic history makes the diagnosis difficult. This difficulty is more challenging when the tooth is placed in the depth of septum. Case Report: Our case is an example of this problem. Herein, we present a case of intraseptal tooth with nasal obstruction and septal deviation and recurrent sinusitis. We present preoperative imaging. Conclusion: Great suspicion may helpful for preoperative diagnosis and good deciding. PMID:24303439

  3. Strontium coating by electrochemical deposition improves implant osseointegration in osteopenic models.

    PubMed

    Liang, Yongqiang; Li, Haoyan; Xu, Jiang; Li, Xin; Li, Xinchang; Yan, Yuting; Qi, Mengchun; Hu, Min

    2015-01-01

    Osteopenia, a preclinical state of osteoporosis, restricts the application of adult orthodontic implant anchorage and tooth implantation. Strontium (Sr) is able to promote bone formation and inhibit bone absorption. The aim of the present study was to evaluate a new method for improving the success rate of dental implantation. In this study, an electrochemical deposition (ECD) method was used to prepare a Sr coating on a titanium implant. The coating composition was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction, and the surface morphology of the coating was studied using scanning electron microscopy. A total of 24 Sprague-Dawley rats received bilateral ovariectomy (OVX) and an additional 12 rats underwent a sham surgery. All rats were then implanted in the bilateral tibiae with titanium mini-implants with or without a Sr coating. The results of histological examination and a fluorescence double labeling assay showed strong new bone formation with a wider zone between the double labels, a higher rate of bone mineralization and better osseointegration in the OVX rats that received Sr-coated implants compared with the OVX rats that received uncoated implants. The study indicates that Sr coatings are easily applied by an ECD method, and that Sr coatings have a promoting effect on implant osseointegration in animals with osteopenia. PMID:25452797

  4. Knowledge and attitudes of dental interns in Karnataka state, India, regarding implants.

    PubMed

    Chaudhary, Sohini; Gowda, Triveni M; Kumar, Tarun A B; Mehta, Dhoom S

    2013-10-01

    Implant treatment today is highly reliable as a valid restorative option for missing teeth. As more patients worldwide opt for implant treatment, it is now imperative for dental practitioners to have sound information about dental implants so they can help patients make informed decisions. This study sought to define the knowledge and attitudes regarding dental implants of dental interns in the state of Karnataka, India, and to evaluate the dental implant curriculum structure at the undergraduate level. A survey was conducted of dental interns (students in their fifth, clinical year of undergraduate study) in seven of the forty-five academic dental institutions in this state. The questionnaire consisted of fifteen questions that assessed the respondents' level of knowledge and source of information regarding implants. A total of 500 questionnaires were distributed, and 417 interns responded for a response rate of 83.4 percent. In the results, 73.3 percent reported they were not provided sufficient information about implants in their undergraduate curriculum, and 95.7 percent of them wanted more. Also, 63.5 percent of the respondents believed that high costs could limit the use of dental implants as a tooth replacement modality in India. This study concludes that revision in the undergraduate dental curricula at these schools is needed to better prepare students for practicing implant dentistry. PMID:24098041

  5. Chemerin-ChemR23 signaling in tooth development.

    PubMed

    Ohira, T; Spear, D; Azimi, N; Andreeva, V; Yelick, P C

    2012-12-01

    Our long-term goal is to identify and characterize molecular mechanisms regulating tooth development, including those mediating the critical dental epithelial-dental mesenchymal (DE-DM) cell interactions required for normal tooth development. The goal of this study was to investigate Chemerin (Rarres2)/ChemR23(Cmklr1) signaling in DE-DM cell interactions in normal tooth development. Here we present, for the first time, tissue-specific expression patterns of Chemerin and ChemR23 in mouse tooth development. We show that Chemerin is expressed in cultured DE progenitor cells, while ChemR23 is expressed in cultured DM cells. Moreover, we demonstrate that ribosomal protein S6 (rS6) and Akt, downstream targets of Chemerin/ChemR23 signaling, are phosphorylated in response to Chemerin/ChemR23 signaling in vitro and are expressed in mouse tooth development. Together, these results suggest roles for Chemerin/ChemR23-mediated DE-DM cell signaling during tooth morphogenesis. PMID:23053848

  6. Clinical efficacy of a new tooth whitening dentifrice.

    PubMed

    Ayad, Farid; Khalaf, Amal; Chaknis, Patricia; Petrone, Margaret E; DeVizio, William; Volpe, Anthony R; Proskin, Howard M

    2002-01-01

    The objective of this double-blind clinical study was to investigate the tooth whitening efficacy of a variation in formula of a commercially available dentifrice (Colgate Total Toothpaste). The variation (Colgate Total Plus Whitening Toothpaste) was the addition of high cleaning silica to the existing formulation. Following a baseline examination for extrinsic tooth stain, qualifying adult male and female subjects from the Mississauga, Ontario, Canada area were randomized into two treatment groups which were balanced for gender, age and level of extrinsic tooth stain. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for extrinsic tooth stain were repeated after six weeks' use of the study dentifrices. Ninety-three (93) subjects complied with the protocol and completed the entire study. At the six-week examination, subjects assigned to the new dentifrice formulation group exhibited statistically significantly lower levels of extrinsic tooth stain area and extrinsic tooth stain intensity than did those subjects assigned to the Colgate Total Toothpaste group. PMID:11695212

  7. Charcot-Marie-Tooth neuropathy type 2A: novel mutations in the mitofusin 2 gene (MFN2)

    PubMed Central

    Engelfried, Kathrin; Vorgerd, Matthias; Hagedorn, Michaela; Haas, Gerhard; Gilles, Jürgen; Epplen, Jörg T; Meins, Moritz

    2006-01-01

    Background Charcot-Marie-Tooth neuropathies are a group of genetically heterogeneous diseases of the peripheral nervous system. Mutations in the MFN2 gene have been reported as the primary cause of Charcot-Marie-Tooth disease type 2A. Methods Patients with the clinical diagnosis of Charcot-Marie-Tooth type 2 were screened using single strand conformation polymorphism (SSCP). All DNA samples showing band shifts in the SSCP analysis were amplified from genomic DNA and cycle sequenced. Results We analyzed a total of 73 unrelated patients with a clinical diagnosis of CMT 2. Overall, novel mutations were detected in 6 patients. c.380G>T (G127V), c.1128G>A (M376I), c.1040A>T (E347V), c.1403G>A (R468H), c.2113G>A (V705I), and c.2258_2259insT (L753fs). Conclusion We confirmed a significant role of mutations in MFN2 in the pathogenesis of Charcot-Marie-Tooth disease type 2. PMID:16762064

  8. Changes in the transmission properties of multi-tooth plasmonic nano-filters (multi-TPNFs) caused by geometrical imperfection

    NASA Astrophysics Data System (ADS)

    Khaksar, A.; Fatemi, H.

    2012-08-01

    To model the filtering behavior of a multi-tooth plasmonic nano-filter (multi-TPNF), an equivalent circuitry composed of a set of serried impedances is considered. The changes caused in its filtering behavior are proposed as a measuring tool to investigate the effect of the geometrical imperfections occurring during the manufacture of the device. Consequently, the effects of changes in the nominal size of each of the geometrical parameters of a multi-TPNF sample, such as its tooth height, d, its tooth width, w, and the separation between two successive teeth, ?, on its transmittance are investigated. It is observed that each single tooth of the multi-TPNF and also the waveguide between any of its two successive teeth exhibit a very Fabry-Perot interferometer like behavior. The variation of the transmission spectra of a multi-TPNF whose geometrical parameters are imperfect is compared with the desired filter, and also the effect of the number of geometrically imperfect teeth of the multi-TPNF on the filtering spectra is examined.

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

    PubMed Central

    Ahn, Se Jin; Chung, Jin Wook; An, Sang Bu; Yin, Yong Hu; Jae, Hwan Jun; Park, Jae Hyung

    2012-01-01

    Objective To assess the technical success and complication rates of the radiologic placement of central venous ports via the internal jugular vein. Materials and Methods We retrospectively reviewed 1254 central venous ports implanted at our institution between August 2002 and October 2009. All procedures were guided by using ultrasound and fluoroscopy. Catheter maintenance days, technical success rates, peri-procedural, as well as early and late complication rates were evaluated based on the interventional radiologic reports and patient medical records. Results A total of 433386 catheter maintenance days (mean, 350 days; range 0-1165 days) were recorded. The technical success rate was 99.9% and a total of 61 complications occurred (5%), resulting in a post-procedural complication rate of 0.129 of 1000 catheter days. Among them, peri-procedural complications within 24 hours occurred in five patients (0.4%). There were 56 post-procedural complications including 24 (1.9%, 0.055 of 1000 catheter days) early and 32 (2.6%, 0.074 of 1000 catheter days) late complications including, infection (0.6%, 0.018 of 10000 catheter days), thrombotic malfunction (1.4%, 0.040 of 1000 catheter days), nonthrombotic malfunction (0.9%, 0.025 of 1000 catheter days), venous thrombosis (0.5%, 0.014 of 1000 catheter days), as well as wound problems (1.1%, 0.032 of 1000 catheter days). Thirty six CVPs (3%) were removed due to complications. Bloodstream infections and venous thrombosis were the two main adverse events prolonging hospitalization (mean 13 days and 5 days, respectively). Conclusion Radiologic placement of a central venous port via the internal jugular vein is safe and efficient as evidenced by its high technical success rate and a very low complication rate. PMID:22563269

  10. A no bleed implant

    Microsoft Academic Search

    Robert A. Ersek; Jose Alberto Navarro; Dora Zsofia Nemeth; George Sas

    1993-01-01

    Breast implants have evolved from the original saline-filled, smooth-surfaced silicone rubber bag to silicone gel-filled smooth-walled sacs to a combination of a silicone gel-filled bag within a saline-filled sac, and, most recently, a reversed, double-lumen implant with a saline bag inside of a gel-filled bag. Texture-surfaced implants were first used in 1970 when the standard silicone gelfilled implant was covered

  11. Tooth-surface-specific Effects of Xylitol

    PubMed Central

    Ritter, A.V.; Bader, J.D.; Leo, M.C.; Preisser, J.S.; Shugars, D.A.; Vollmer, W.M.; Amaechi, B.T.; Holland, J.C.

    2013-01-01

    The Xylitol for Adult Caries Trial was a three-year, double-blind, multi-center, randomized clinical trial that evaluated the effectiveness of xylitol vs. placebo lozenges in the prevention of dental caries in caries-active adults. The purpose of this secondary analysis was to investigate whether xylitol lozenges had a differential effect on cumulative caries increments on different tooth surfaces. Participants (ages 21-80 yrs) with at least one follow-up visit (n = 620) were examined at baseline, 12, 24, and 33 months. Negative binomial and zero-inflated negative binomial regression models were used to estimate incidence rate ratios (IRR) for xylitol’s differential effect on cumulative caries increments on root and coronal surfaces and, among coronal surfaces, on smooth (buccal and lingual), occlusal, and proximal surfaces. Participants in the xylitol arm developed 40% fewer root caries lesions (0.23 D2FS/year) than those in the placebo arm (0.38 D2FS/year; IRR = 0.60; 95% CI [0.44, 0.81]; p < .001). There was no statistically significant difference between xylitol and control participants in the incidence of smooth-surface caries (p = .100), occlusal-surface caries (p = .408), or proximal-surface caries (p = .159). Among these caries-active adults, xylitol appears to have a caries-preventive effect on root surfaces (ClinicalTrials.gov NCT00393055). PMID:23589387

  12. Cochlear Implants for Children.

    ERIC Educational Resources Information Center

    Hasenstab, M. Suzanne; Laughton, Joan

    1991-01-01

    The use of cochlear implants in children with profound bilateral hearing loss is discussed, focusing on how a cochlear implant works; steps in a cochlear implant program (evaluation, surgery, programing, and training); and rehabilitation procedures involved in auditory development and speech development. (JDD)

  13. Periodontal ligament influence on the stress distribution in a removable partial denture supported by implant: a finite element analysis

    PubMed Central

    ARCHANGELO, Carlos Marcelo; ROCHA, Eduardo Passos; PEREIRA, João Antônio; MARTIN JUNIOR, Manoel; ANCHIETA, Rodolfo Bruniera; FREITAS JÚNIOR, Amilcar Chagas

    2012-01-01

    ABSTRACT Objective The non-homogenous aspect of periodontal ligament (PDL) has been examined using finite element analysis (FEA) to better simulate PDL behavior. The aim of this study was to assess, by 2-D FEA, the influence of non-homogenous PDL on the stress distribution when the free-end saddle removable partial denture (RPD) is partially supported by an osseointegrated implant. Material and Methods Six finite element (FE) models of a partially edentulous mandible were created to represent two types of PDL (non-homogenous and homogenous) and two types of RPD (conventional RPD, supported by tooth and fibromucosa; and modified RPD, supported by tooth and implant [10.00x3.75 mm]). Two additional FE models without RPD were used as control models. The non-homogenous PDL was modeled using beam elements to simulate the crest, horizontal, oblique and apical fibers. The load (50 N) was applied in each cusp simultaneously. Regarding boundary conditions the border of alveolar ridge was fixed along the x axis. The FE software (Ansys 10.0) was used to compute the stress fields, and the von Mises stress criterion (?vM) was applied to analyze the results. Results The peak of ?vM in non-homogenous PDL was higher than that for the homogenous condition. The benefits of implants were enhanced for the non-homogenous PDL condition, with drastic ?vM reduction on the posterior half of the alveolar ridge. The implant did not reduce the stress on the support tooth for both PDL conditions. Conclusion The PDL modeled in the non-homogeneous form increased the benefits of the osseointegrated implant in comparison with the homogeneous condition. Using the non-homogenous PDL, the presence of osseointegrated implant did not reduce the stress on the supporting tooth. PMID:22858705

  14. Modified Titanium Implant as a Gateway to the Human Body: The Implant Mediated Drug Delivery System

    PubMed Central

    Park, Young-Seok; Cho, Joo-Youn; Hwang, Chee Il

    2014-01-01

    The aim of this study was to investigate the efficacy of a proposed new implant mediated drug delivery system (IMDDS) in rabbits. The drug delivery system is applied through a modified titanium implant that is configured to be implanted into bone. The implant is hollow and has multiple microholes that can continuously deliver therapeutic agents into the systematic body. To examine the efficacy and feasibility of the IMDDS, we investigated the pharmacokinetic behavior of dexamethasone in plasma after a single dose was delivered via the modified implant placed in the rabbit tibia. After measuring the plasma concentration, the areas under the curve showed that the IMDDS provided a sustained release for a relatively long period. The result suggests that the IMDDS can deliver a sustained release of certain drug components with a high bioavailability. Accordingly, the IMDDS may provide the basis for a novel approach to treating patients with chronic diseases. PMID:25136624

  15. Shading of ceramic crowns using digital tooth shade matching devices.

    PubMed

    Baltzer, A; Kaufmann-Jinoian, V

    2005-04-01

    In the 1990s, there was great optimism due to the development of devices for measuring tooth shade. The frequently not so simple, visual determination of the shade of a tooth was to be done with the aid of a device which recognizes the shade and describes it accurately by reference to a color chart. However, the skepticism towards such devices was also great. It is known that the color effect frequently differs strongly when comparing a tooth from the shade guide with a metal ceramic crown, despite identical shade designation. Anyone who considers visual shade determination to be inadequate and places his hopes in digital shade matching devices will be disappointed. It is the shade-generating structures of the metal ceramic and frequently of the veneer layers that turn out to be too thin which, despite correct shade selection, cause a different color perception. Such problems have been reduced decisively with the development of fracture-proof hard porcelain caps (Vita In-Ceram) with optical characteristics similar to teeth. In addition, the Vita System 3D-Master tooth shade system developed in 1998 by Vita in cooperation with Dr. Hall from Australia, leads the practitioner to a better understanding of the primary tooth shade characteristics of "brightness (value)", "color intensity (chroma)" and "color (wave length of the visible light, hue)". These two innovations allow a more accurate estimate of the basic shade of a natural tooth (reference tooth) and the imitation in the laboratory of its natural, shade-generating structures. If digital shade measurement supplements the visual shade estimate, then a further improvement can be expected--especially in the recognition of the basic shade. Qualitative descriptions of subjective shade measurement of a natural tooth and of its imitation in the dental laboratory by ceramics can be found frequently in professional journals and publications. With digital tooth shade matching devices, which apart from the color code of the color chart also reproduce exact, colorimetric values, such work processes can be recorded quantitatively and objectively. Reports about this type of controlled shade determination and generation are found rarely in the literature, which is surprising in view of the large number of tooth shade matching devices and dental ceramic systems available. In the present paper, the influence of the individual ceramic layers on color perception is measured and described under standardized conditions. The creation of the basic shade as it results from the composition of the various ceramic layers is traced with a spectrophotometer. The Vita In-Ceram Alumina infiltration ceramic and the VitaVM7 veneer ceramic were selected as the ceramic system. MHT-SpectroShade and Vita Easyshade were used as shade matching devices. PMID:16201397

  16. Crystallinity of freestanding large undoped single crystal diamond plates produced using pre-ion-implanted substrates and lift-off processes

    Microsoft Academic Search

    Nobuteru Tsubouchi; Y. Mokuno; A. Chayahara; S. Shikata

    2010-01-01

    Crystallinity of freestanding large (size: ?9×9mm) undoped single crystal (SC) diamond films grown by plasma chemical vapor deposition (CVD) was investigated using optical transmission spectroscopy, polarized optical microscope, X-ray rocking curves, X-ray topographs and photoluminescence. The production of the freestanding film was performed by elimination of the substrates using a so-called “lift-off method” after the growth of a homoepitaxial thick-film

  17. Effects of Ion-Releasing Tooth-Coating Material on Demineralization of Bovine Tooth Enamel

    PubMed Central

    Kawasaki, Koji; Kambara, Masaki

    2014-01-01

    We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

  18. Effects of ion-releasing tooth-coating material on demineralization of bovine tooth enamel.

    PubMed

    Kawasaki, Koji; Kambara, Masaki

    2014-01-01

    We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

  19. In vitro evaluation of tooth-color change using four paint-on tooth whiteners.

    PubMed

    Kishta-Derani, Maryam; Neiva, Gisele; Yaman, Peter; Dennison, Joseph

    2007-01-01

    The effectiveness of four paint-on tooth whiteners was evaluated and compared in this in vitro study. Sixty extracted anterior teeth were selected and randomly assigned to five groups: 1-(AS) Artificial Saliva (Roxane); 2-(MSW) Sparkling White (Meijer); 3-(CNE) Crest Night Effects (Procter & Gamble); 4-(ABB) Beautifully Bright (Avon) and 5-(CSWN) Simply White Night Gel (Colgate-Palmolive). The teeth were cleaned with a soft bristle toothbrush and toothpaste (Procter & Gamble) to remove any residue from the storage solution. The bleaching gels were painted onto the surface of the teeth, and they were then wrapped in gauze moistened with artificial saliva and kept in 100% humidity at 98 degrees F in a laboratory oven (Precision Scientific model 18EG) for 24 hours. The treatment was repeated once a day for 14 days. Visual color assessment was done using a value-oriented Vitapan Classical Shade Guide (Vident) and a colorimeter (Minolta Chroma Meter CR 321). PVS jigs (Exaflex, GC America) were fabricated for each tooth. Visual and colorimetric readings were recorded at baseline, 7 and 14 days. One-way ANOVA and Tukey multiple comparisons test were used to assess differences between groups. CNE and CSWN presented the highest mean number of shade changes and deltaE*ab Colorimeter readings. ABB and MSW did not significantly lighten the teeth, as measured by either method of evaluation after two weeks of the bleaching regimen. PMID:17695613

  20. Experimental investigation of fatigue behavior of spur gear in altered tooth-sum gearing

    NASA Astrophysics Data System (ADS)

    Sachidananda, H. K.; Gonsalvis, Joseph; Prakash, H. R.

    2012-09-01

    This paper deals with the contact stress, power loss, and pitting of spur gear tooth in altered tooth-sum gearing for a tooth-sum of 100 teeth when altered by ±4% tooth-sum. Analytical and experimental methods were performed to investigate and compare the altered tooth-sum gearing against the standard tooth-sum gearing. The experiments were performed using a power recirculating type test rig. The tooth loads for the experimental investigations were determined considering the surface durability of gears. A clear picture of the surface damage was obtained using a scanning electron microphotograph. The negative alteration in the tooth-sum performed better than the positive alteration in a tooth-sum operating between specified center distances.

  1. Tooth wear in three ethnic groups in Sabah (northern Borneo).

    PubMed

    Milosevic, A; Lo, M S

    1996-12-01

    The prevalence and associated aetiologies of tooth wear were investigated in three ethnic groups in Sabah (Northern Borneo) using the Tooth Wear Index (TWI). The number of surfaces with enamel wear only, dentine exposed for less than a third or dentine exposed for more than a third were categorised into the TW minimal, moderate or severe respectively. A structured questionnaire was used to elicit medical/dental history, oral hygiene practices, satisfaction with body image, diet and other personal habits/details. The sample comprised of a self selected sample of 148 dental hospital attenders; 47 (32 per cent) each of ethnic Chinese and Malay and 54 (36 per cent) of ethnic Kadazan, matched for age and with a similar number of scoreable teeth per subject. Dentine exposure within the total sample was a common finding (95 per cent TW with moderate, 41 per cent TW severe). The Kadazan group had significantly (P < 0.05) more surfaces with severe tooth wear than the Chinese or Malay. Tobacco chewing was positively associated (rho = +0.4, P < 0.05) with both moderate and severe tooth wear, as was the habit of crushing/eating bones. Neither carbonated beverages or fresh fruit intake were associated with tooth wear, but their frequency of consumption was low. The buccal and occlusal surfaces of the posterior teeth were the most severely worn. Generally, wear was greater in the upper anterior sextant compared to the lower anterior sextant, with the exception of the lower incisal edges in the Kadazan group. Tooth wear into dentine was a common occurrence, especially among the Kadazan subjects and least among the Chinese subjects. The aetiological factors associated with this tooth wear are different to those encountered in Western cultures. PMID:9023582

  2. The saddle connective tissue graft: a periodontal plastic surgery technique to obtain soft tissue coronal gain on immediate implants. A case report.

    PubMed

    González, David; Cabello, Gustavo; Olmos, Gema; Niñoles, Carlos L

    2015-01-01

    Based on recent studies regarding the advantages of flapless immediate implants on the maintenance of the soft tissue architecture (especially at papillae level) in those situations where it is necessary to extract an anterior tooth, this case report describes a clinical procedure designed to replace a hopeless central incisor (2.1) showing root resorption adjacent to an implant-supported crown (1.1), whose gingival margin is 2 mm coronal regarding the hopeless tooth to be replaced. After the extraction of the hopeless tooth (2.1), a flapless immediate implant was placed. The implant-bone gap was then filled with bone substitute and a palatal connective tissue graft was placed ad modum saddle extending at buccal level from apical to the mucogingival line, sealing the socket and extending until 6 mm at palatal level ad modum saddle. This procedure allowed symmetry of the soft tissue margins between the two implants (1.1 and 2.1) to be obtained as well as the preservation of the inter-implant papillae (1.1). PMID:26171446

  3. An Aberrant Splice Acceptor Site Due to a Novel Intronic Nucleotide Substitution in MSX1 Gene Is the Cause of Congenital Tooth Agenesis in a Japanese Family

    PubMed Central

    Tatematsu, Tadashi; Kimura, Masashi; Nakashima, Mitsuko; Machida, Junichiro; Yamaguchi, Seishi; Shibata, Akio; Goto, Hiroki; Nakayama, Atsuo; Higashi, Yujiro; Miyachi, Hitoshi; Shimozato, Kazuo; Matsumoto, Naomichi; Tokita, Yoshihito

    2015-01-01

    Congenital tooth agenesis is caused by mutations in the MSX1, PAX9, WNT10A, or AXIN2 genes. Here, we report a Japanese family with nonsyndromic tooth agenesis caused by a novel nucleotide substitution in the intronic region between exons 1 and 2 of the MSX1 gene. Because the mutation is located 9?bp before exon 2 (c.452-9G>A), we speculated that the nucleotide substitution would generate an abnormal splice site. Using cDNA analysis of an immortalized patient blood cell, we confirmed that an additional 7-nucleotide sequence was inserted at the splice junction between exons 1 and 2 (c.451_452insCCCTCAG). The consequent frameshift generated a homeodomain-truncated MSX1 (p.R151fsX20). We then studied the subcellular localization of truncated MSX1 protein in COS cells, and observed that it had a whole cell distribution more than a nuclear localization, compared to that of wild-type protein. This result suggests a deletion of the nuclear localization signal, which is mapped to the MSX1 homeodomain. These results indicate that this novel intronic nucleotide substitution is the cause of tooth agenesis in this family. To date, most MSX1 variants isolated from patients with tooth agenesis involve single amino acid substitutions in the highly conserved homeodomain or deletion mutants caused by frameshift or nonsense mutations. We here report a rare case of an intronic mutation of the MSX1 gene responsible for human tooth agenesis. In addition, the missing tooth patterns were slightly but significantly different between an affected monozygotic twin pair of this family, showing that epigenetic or environmental factors also affect the phenotypic variations of missing teeth among patients with nonsyndromic tooth agenesis caused by an MSX1 haploinsufficiency. PMID:26030286

  4. Effect of platelet-rich plasma and platelet-rich fibrin on peri-implant bone defects in dogs.

    PubMed

    Jeong, Kyung-In; Kim, Su-Gwan; Oh, Ji-Su; Lee, Sung-Yong; Cho, Young-Seung; Yang, Sung-Soo; Park, Seung-Cheol; You, Jae-Seek; Lim, Sung-Chul; Jeong, Mi-Ae; Kim, Jae-Sung; Lee, Sook-Young

    2013-03-01

    The purpose of this study was to evaluate the effect of tooth ash and platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) grafts into bone defects around implants on bone formation. Six adult dogs were used as experimental subjects. Graft materials were used to create a particulate material. Forty-eight tapered-type implants, 3.7 mm in diameter, 10 mm in length, and with surface treated with hydroxyapatite (HA) coating, were used as implant fixtures. Using a trephine bur, four bone defects were formed and implants were placed in the femurs of the adult dogs. Bone grafts were not performed in the control group. Tooth ash was grafted into the defects in group 1. In group 2, a mixture of tooth ash and PRP (1:1 ratio by volume) was grafted into the defects. In group 3, a mixture of tooth ash and PRF (ratio of 1:1) was grafted in the defect area. Animals were sacrificed after 4 or 8 weeks. Based on histopathological examination, the amount and rate of new bone formation were evaluated. Histomorphometric examination revealed that the rate of new bone formation in group 3 of the 4-week group was significantly higher than that in the control group. In addition, in the 8-week group, a significant increase in new bone formation was confirmed in group 3. In this study, a bone graft method using a mixture of tooth ash and PRF was found to increase new bone formation compared to the method using PRP. In addition, it was confirmed that this effect was more prominent in the initial stage of the bone graft. PMID:23621011

  5. Combination of natural teeth and osseointegrated implants as prosthesis abutments: a 2-year longitudinal study.

    PubMed

    Astrand, P; Borg, K; Gunne, J; Olsson, M

    1991-01-01

    Twenty-three patients with Kennedy Class I mandibular dentition were supplied with prostheses in the posterior parts of the mandible. On one side they were given a prosthesis supported by two implants (prosthesis Type I) and on the other side they received a prosthesis supported by one implant and one natural tooth (prosthesis Type II). Sixty-nine fixtures were inserted and 46 prostheses constructed. Eight of the fixtures were lost during the observation period. The failure rate of the implants was about the same in the two types of prostheses; five fixtures belonged to prostheses Type I (10.9%) and two fixtures belonged to prostheses Type II (8.7%), while one fixture was lost prior to loading. From a theoretical point of view, the combination of a tooth and an osseointegrated implant should encounter problems with regard to the difference in bone anchorage and there should be a risk of biomechanical complications. However, the results of this study did not indicate any disadvantages in connecting teeth and implants in the same restoration. PMID:1813398

  6. A Systematic Study on Tooth Enamel Microstructures of Lambdopsalis bulla (Multituberculate, Mammalia) - Implications for Multituberculate Biology and Phylogeny.

    PubMed

    Mao, Fangyuan; Wang, Yuanqing; Meng, Jin

    2015-01-01

    Tooth enamel microstructure is a reliable and widely used indicator of dietary interpretations and data for phylogenetic reconstruction, if all levels of variability are investigated. It is usually difficult to have a thorough examination at all levels of enamel structures for any mammals, especially for the early mammals, which are commonly represented by sparse specimens. Because of the random preservation of specimens, enamel microstructures from different teeth in various species are often compared. There are few examples that convincingly show intraspecific variation of tooth enamel microstructure in full dentition of a species, including multituberculates. Here we present a systematic survey of tooth enamel microstructures of Lambdopsalis bulla, a taeniolabidoid multituberculate from the Late Paleocene Nomogen Formation, Inner Mongolia. We examined enamel structures at all hierarchical levels. The samples are treated differently in section orientations and acid preparation and examined using different imaging methods. The results show that, except for preparation artifacts, the crystallites, enamel types, Schmelzmuster and dentition types of Lambdopsalis are relatively consistent in all permanent teeth, but the prism type, including the prism shape, size and density, may vary in different portions of a single tooth or among different teeth of an individual animal. The most common Schmelzmuster of the permanent teeth in Lambdopsalis is a combination of radial enamel in the inner and middle layers, aprismatic enamel in the outer layer, and irregular decussations in tooth crown area with great curvature. The prism seam is another comparably stable characteristic that may be a useful feature for multituberculate taxonomy. The systematic documentation of enamel structures in Lambdopsalis may be generalized for the enamel microstructure study, and thus for taxonomy and phylogenetic reconstruction, of multituberculates and even informative for the enamel study of other early mammals. PMID:26020958

  7. A Systematic Study on Tooth Enamel Microstructures of Lambdopsalis bulla (Multituberculate, Mammalia) - Implications for Multituberculate Biology and Phylogeny

    PubMed Central

    Mao, Fangyuan; Wang, Yuanqing; Meng, Jin

    2015-01-01

    Tooth enamel microstructure is a reliable and widely used indicator of dietary interpretations and data for phylogenetic reconstruction, if all levels of variability are investigated. It is usually difficult to have a thorough examination at all levels of enamel structures for any mammals, especially for the early mammals, which are commonly represented by sparse specimens. Because of the random preservation of specimens, enamel microstructures from different teeth in various species are often compared. There are few examples that convincingly show intraspecific variation of tooth enamel microstructure in full dentition of a species, including multituberculates. Here we present a systematic survey of tooth enamel microstructures of Lambdopsalis bulla, a taeniolabidoid multituberculate from the Late Paleocene Nomogen Formation, Inner Mongolia. We examined enamel structures at all hierarchical levels. The samples are treated differently in section orientations and acid preparation and examined using different imaging methods. The results show that, except for preparation artifacts, the crystallites, enamel types, Schmelzmuster and dentition types of Lambdopsalis are relatively consistent in all permanent teeth, but the prism type, including the prism shape, size and density, may vary in different portions of a single tooth or among different teeth of an individual animal. The most common Schmelzmuster of the permanent teeth in Lambdopsalis is a combination of radial enamel in the inner and middle layers, aprismatic enamel in the outer layer, and irregular decussations in tooth crown area with great curvature. The prism seam is another comparably stable characteristic that may be a useful feature for multituberculate taxonomy. The systematic documentation of enamel structures in Lambdopsalis may be generalized for the enamel microstructure study, and thus for taxonomy and phylogenetic reconstruction, of multituberculates and even informative for the enamel study of other early mammals. PMID:26020958

  8. Amorphous clusters in Co implanted ZnO induced by boron pre-implantation

    SciTech Connect

    Potzger, K.; Shalimov, A.; Zhou, S.; Schmidt, H.; Mucklich, A.; Helm, M.; Fassbender, J.; Liberati, M.; Arenholz, E.

    2009-02-09

    We demonstrate the formation of superparamagnetic/ferromagnetic regions within ZnO(0001) single crystals sequently implanted with B and Co. While the pre-implantation with B plays a minor role for the electrical transport properties, its presence leads to the formation of amorphous phases. Moreover, B acts strongly reducing on the implanted Co. Thus, the origin of the ferromagnetic ordering in local clusters with large Co concentration is itinerant d-electrons as in the case of metallic Co. The metallic amorphous phases are non-detectable by common X-ray diffraction.

  9. Successful implantation of a cardioverter defibrillator in an infant.

    PubMed

    Watanabe, H; Hayashi, J; Haga, M; Saito, M; Suzuki, H; Sato, S

    2001-12-01

    We report the successful implantation of a cardioverter defibrillator (ICD) in a 12-month-old infant. A single-lead ICD using an epicardial patch and a cathodal pulse-generator titanium shell electrode was very useful for implantation in this infant. PMID:11789812

  10. Ion implantation of diamond: Damage, doping, and lift-off

    Microsoft Academic Search

    N. R. Parikh; E. McGucken; M. L. Swanson; J. D. Hunn; C. W. White; R. A. Zuhr

    1993-01-01

    In order to make good quality economical diamond electronic devices, it is essential to grow films and to dope these films to obtain n- and p- type conductivity. This review discusses doping by ion implantation and the production of large area single crystal diamonds. The C implantation damage below an estimated Frenkel defect concentration of 7% could be recovered by

  11. Implant Reconstruction in Breast Cancer Patients Treated with Radiation Therapy

    Microsoft Academic Search

    Jeffrey A. Ascherman; Matthew M. Hanasono; Martin I. Newman; Duncan B. Hughes

    2006-01-01

    Background: Implant reconstruction in breast cancer patients treated with radiation therapy is controversial. Prior studies are limited by older prosthetic devices, reconstructive techniques, and radiation therapy protocols. Methods: A retrospective review was performed of patients who underwent tissue expansion and implant breast reconstruction performed by a single sur- geon after mastectomy for breast cancer from 1996 to 2003. Complications and

  12. Performance of laser fluorescence at tooth surface and histological section.

    PubMed

    Jablonski-Momeni, Anahita; Ricketts, David N J; Rolfsen, Stefanie; Stoll, Richard; Heinzel-Gutenbrunner, Monika; Stachniss, Vitus; Pieper, Klaus

    2011-03-01

    This study aimed to evaluate a laser fluorescence device (the DIAGNOdent) and a visual classification system (ICDAS-II) for occlusal caries diagnosis. It also aimed to determine whether fluorescence measurements taken at the tooth surface correlate with the fluorescence measurements taken within the body of the lesion. The occlusal surfaces of 100 extracted permanent teeth were examined using ICDAS-II and DIAGNOdent (LF-tooth). Serial sections were made and lesion depth was assessed histologically. DIAGNOdent readings were also taken from the sections (LF-section). There were significant positive strong correlations between ICDAS-II and histology (r(S)?=?0.71) and LF-section and histology (r(S)?=?0.70), and only moderate correlations between LF-tooth and histology (r(S)?=?0.51) and LF-tooth and LF-section (r(S)?=?0.60). Diagnostic accuracy for ICDAS-II was generally better than for LF-tooth. While the DIAGNOdent device provides an objective reading for detection and monitoring of carious lesions, using the cut-off ranges previously suggested leads to inferior performance. PMID:20221781

  13. Canine tooth size and fitness in male mandrills (Mandrillus sphinx).

    PubMed

    Leigh, Steven R; Setchell, Joanna M; Charpentier, Marie; Knapp, Leslie A; Wickings, E Jean

    2008-07-01

    Sexual selection theory explains the evolution of exaggerated male morphologies and weaponry, but the fitness consequences of developmental and age-related changes in these features remain poorly understood. This long-term study of mandrill monkeys (Mandrillus sphinx) demonstrates how age-related changes in canine tooth weaponry and adult canine size correlate closely with male lifetime reproductive success. Combining long-term demographic and morphometric data reveals that male fitness covaries simply and directly with canine ontogeny, adult maximum size, and wear. However, fitness is largely independent of other somatometrics. Male mandrills sire offspring almost exclusively when their canines exceed approximately 30 mm, or two-thirds of average adult value (45 mm). Moreover, sires have larger canines than nonsires. The tooth diminishes through wear as animals age, corresponding with, and perhaps influencing, reproductive senescence. These factors combine to constrain male reproductive opportunities to a brief timespan, defined by the period of maximum canine length. Sexually-selected weaponry, especially when it is nonrenewable like the primate canine tooth, is intimately tied to the male life course. Our analyses of this extremely dimorphic species indicate that sexual selection is closely intertwined with growth, development, and aging, pointing to new directions for sexual selection theory. Moreover, the primate canine tooth has potential as a simple mammalian system for testing genetically-based models of aging. Finally, the tooth may record details of life histories in fossil primates, especially when sexual selection has played a role in the evolution of dimorphism. PMID:18472142

  14. Method for implantation of high dopant concentrations in wide band gap materials

    DOEpatents

    Usov, Igor (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM)

    2009-09-15

    A method that combines alternate low/medium ion dose implantation with rapid thermal annealing at relatively low temperatures. At least one dopant is implanted in one of a single crystal and an epitaxial film of the wide band gap compound by a plurality of implantation cycles. The number of implantation cycles is sufficient to implant a predetermined concentration of the dopant in one of the single crystal and the epitaxial film. Each of the implantation cycles includes the steps of: implanting a portion of the predetermined concentration of the one dopant in one of the single crystal and the epitaxial film; annealing one of the single crystal and the epitaxial film and implanted portion at a predetermined temperature for a predetermined time to repair damage to one of the single crystal and the epitaxial film caused by implantation and activates the implanted dopant; and cooling the annealed single crystal and implanted portion to a temperature of less than about 100.degree. C. This combination produces high concentrations of dopants, while minimizing the defect concentration.

  15. C-telopeptide pyridinoline cross-links (ICTP) and periodontal pathogens associated with endosseous oral implants.

    PubMed

    Oringer, R J; Palys, M D; Iranmanesh, A; Fiorellini, J P; Haffajee, A D; Socransky, S S; Giannobile, W V

    1998-12-01

    Detection of periodontal or peri-implant sites exhibiting progressing disease or those at risk of deterioration has proven difficult. Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), a marker specific for bone degradation found in gingival crevicular fluid (GCF), has been associated with both bone and attachment loss in periodontitis and may be useful for predicting disease activity. The aim of this cross-sectional study was to examine the relationship between ICTP levels and subgingival species around implants and teeth from 20 partially and 2 fully edentulous patients. GCF and plaque samples were collected from the mesiobuccal site of each implant and tooth. Radioimmunoassay techniques were utilized to determine GCF ICTP levels. Plaque samples were analyzed utilizing checkerboard DNA-DNA hybridization. Traditional clinical parameters were assessed. Seventy-one implants and 370 teeth from 22 subjects were examined. ICTP levels and subgingival plaque composition were not significantly different between implants and teeth. Implant sites colonized by Prevotella intermedia, Capnocytophaga gingivalis, Fusobacterium nucleatum ss vincentii, and Streptococcus gordonii exhibited odds ratios of 12.4, 9.3, 8.1, and 6.7, respectively of detecting ICTP. These results suggest a relationship between elevated ICTP levels at implant sites and some species associated with disease progression. Longitudinal studies are necessary to determine whether elevated ICTP levels may predict the development of peri-implant bone loss. PMID:11429938

  16. C-Telopeptide pyridinoline cross-links (ICTP) and periodontal pathogens associated with endosseous oral implants

    PubMed Central

    Oringer, R. J.; Palys, M. D.; Iranmanesh, A.; Fiorellini, J. P.; Haffajee, A. D.; Socransky, S. S.; Giannobile, W. V.

    2009-01-01

    Detection of periodontal or peri-implant sites exhibiting progressing disease or those at risk of deterioration has proven difficult. Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), a marker specific for bone degradation found in gingival crevicular fluid (GCF), has been associated with both bone and attachment loss in periodontitis and may be useful for predicting disease activity. The aim of this cross-sectional study was to examine the relationship between ICTP levels and subgingival species around implants and teeth from 20 partially and 2 fully edentulous patients. GCF and plaque samples were collected from the mesiobuccal site of each implant and tooth. Radioimmunoassay techniques were utilized to determine GCF ICTP levels. Plaque samples were analyzed utilizing checkerboard DNA-DNA hybridization. Traditional clinical parameters were assessed. Seventy-one implants and 370 teeth from 22 subjects were examined. ICTP levels and subgingival plaque composition were not significantly different between implants and teeth. Implant sites colonized by Pre-votella intermedia, Capnocytophaga gingivalis, Fusobacterium nucleatum ss vincentii, and Streptococcus gordonii exhibited odds ratios of 12.4, 9.3, 8.1, and 6.7, respectively of detecting ICTP. These results suggest a relationship between elevated ICTP levels at implant sites and some species associated with disease progression. Longitudinal studies are necessary to determine whether elevated ICTP levels may predict the development of peri-implant bone loss. PMID:11429938

  17. Comparative Clinical Study of Two Tooth Bleaching Protocols with 6% Hydrogen Peroxide

    PubMed Central

    Oteo Calatayud, Jesús; Mateos de la Varga, Paloma; Oteo Calatayud, Carlos; Calvo Box, María José

    2009-01-01

    Objective. The objective was to compare the clinical efficacy of two different tooth bleaching protocols after 1 and 2 weeks of treatment with an over-the-counter paint-on gel containing 6% hydrogen peroxide. Material and methods. Sixteen volunteer patients (minimum shade A2 or darker on maxillary teeth) were selected to participate in this randomized, single-blind (examiner-blinded), single-center, 2-group clinical trial using a divided mouth model. The product was applied in our clinic to one hemi-arch (Group I) in each patient at two sessions one week apart, making five applications at each session (separated by 10 min intervals). The patients themselves applied the product once a day for 10 days in the other hemiarch (Group II). Efficacy was measured according to the Vita Classical shade guide at baseline and at one and two weeks. Differences between groups (office-treated vs. home-treated hemiarches) were tested by repeated-measures analysis of variance. Results. Significant (P < .05) differences in shade values were detected between pre- and post-bleaching in both groups. The two groups did not significantly differ in tooth shade at the end of the treatment. Conclusions. Treatment with 6% hydrogen peroxide gel using the paint-on system shows significant clinical efficacy whether applied by clinicians or by the patients themselves. PMID:20339457

  18. All the Mandibular Incisors with Double Canals in a Single Patient: A Rare Case

    PubMed Central

    Daokar, Sadashiv G; Kalekar (Yadao), Anita S; Ghunawat, Dhananjay B; Kakde, Deepak D

    2015-01-01

    Single rooted tooth are considered to be the easiest for root canal treatment. The literature has documented cases with single rooted tooth showing more than single canal. Understanding of root canal morphology thus is an important aspect to be considered for successful endodontic treatment. The case presented here shows a rare entity of having double canals in all the mandibular incisors in a single patient. PMID:25859107

  19. Studies on Bilateral Cochlear Implants at the University of Wisconsin's Binaural Hearing

    E-print Network

    Litovsky, Ruth

    Studies on Bilateral Cochlear Implants at the University of Wisconsin's Binaural Hearing and Speech with a single cochlear implant (CI), focusing on measures of spatial hearing and speech understanding in noise rehabilitation, cochlear implants, diagnostic techniques, hearing science, speech perception Abbreviations: BHSL

  20. Role of Homeobox Genes in Tooth Morphogenesis: A Review

    PubMed Central

    Suryadeva, Sreevalli

    2015-01-01

    In oral cavity, disturbances due to genetic alterations may range from lack of tooth development to morphological defects. Due to technical advances in genetic engineering and molecular biology, valuable information regarding dentofacial growth could be studied in detailed manner. This helped us to explain the aetiology and pathogenesis of many dentofacial disorders. The success in treatment lies first in determining the aetiology of tooth anomalies and finally differentiating the effect of genes and environment on the orofacial diseases of that particular individual. Several genes belonging to class II homeobox families are expressed during odontogenesis however homeobox genes are not directly imvolved in tooth formation as they are not directly expressed in the first branchial arch derivatives. PMID:25859538

  1. From Hopeless to Good Prognosis: Journey of a Failing Tooth

    PubMed Central

    Gupta, Saurabh; Deshmukh, Jeevanand; Khatri, Richa; Kulkarni, Vinaya Kumar; Karthik, B

    2015-01-01

    Chronic periodontitis, along with associated clinical findings such as pathologic tooth migration, diastema, functional and aesthetic aberrations, poses an immense challenge to a dental professional. These findings convert clinical decision making into a daunting task and adversely affect the prognosis and the treatment plan for the presenting clinical problem. An interdisciplinary approach aimed at restoring functional and aesthetic needs of the affected individual within the limitations of such a compromised clinical scenario may be a viable alternative to any radical treatment causing loss of natural tooth structure such as extraction. This article reports the usefulness of the interdisciplinary route for managing an otherwise hopeless clinical situation of chronic periodontitis complicated with extreme mobility and pathologic tooth migration, which resulted in compromised function and aesthetics. PMID:25859109

  2. Tooth Loss Strongly Associates With Malnutrition in Chronic Kidney Disease

    PubMed Central

    Ioannidou, E.; Swede, H.; Fares, G.; Himmelfarb, J.

    2015-01-01

    Background In chronic kidney disease (CKD), inadequate nutritional intake, inflammation, and increased oxidative stress have been the major contributing factors in malnutrition pathogenesis. However, there is still a paucity of evidence assessing the magnitude of the effect of tooth loss on malnutrition in CKD populations. The authors hypothesize that among patients with CKD, tooth loss may affect nutritional status, using the National Health and Nutrition Examination Survey 1988 to 1994 (NHANES III). Methods Glomerular filtration rate (GFR) was estimated based on cystatin C levels using the relevant equation. Urinary albumin-to-creatinine ratio (albuminuria) was calculated in milligrams per gram with a cutoff point of 30 mg/g. CKD was defined based on estimated GFR <60 mL/minute/1.73m2 and albuminuria ?30 mg/g. The cutoff point for serum albumin was set at 3.7 g/dL. Tooth loss categories were based on the number of missing and replaced teeth. Results A total of 2,749 patients was included and stratified based on their oral health status. There was a statistically significant correlation between tooth loss and the proportion of patients with low protein and caloric intake (P = 0.02 and 0.01, respectively). Serum albumin reached a frequency peak in the fully edentulous group without dentures (group 4, 19.2%). In the same group, individuals had lower protein (30.1%) and caloric intake (30.2%) (P = 0.01 and 0.02, respectively). Furthermore, logistic regression analysis confirmed the significant role of tooth loss on serum albumin and protein and energy intake in this population even after adjusting for confounding variables. Conclusion Tooth loss independently predicts low energy and protein intake, as well as serum albumin levels, biomarkers of malnutrition in CKD. PMID:24215204

  3. Genetic Approaches for the Diagnosis and Treatment of Congenital Tooth Agenesis

    E-print Network

    Bonds, John Carless

    2014-08-06

    Congenital tooth agenesis is the most common developmental anomaly in man. More severe forms of tooth agenesis (> 5 missing teeth) demand lengthy and expensive treatment approaches such as bone augmentation surgeries and placement of multiple...

  4. Tooth resorption part II - external resorption: Case series

    PubMed Central

    Fernandes, Marina; de Ataide, Ida; Wagle, Rahul

    2013-01-01

    External tooth resorption usually follows trauma to the periodontal ligament. It can be classified into five categories based on its clinical and histological manifestations. Calcium hydroxide has long been used as an intracanal medicament to slow down the resorption process due to its alkaline pH. A combination of both external and internal resorptions can also occur on the same tooth, making the management more complex. Five case reports of external resorption have been presented in this article along with pertinent review of literature. Successful management was possible in two cases, while extractions had to be advised in 3 cases due to advanced nature of the lesions. PMID:23716975

  5. Mössbauer study of Fe in GaAs following 57 Mn ?+? implantation

    Microsoft Academic Search

    K. Bharuth-Ram; H. P. Gunnlaugsson; G. Weyer; R. Mantovan; D. Naidoo; R. Sielemann; M. Fanciulli; G. Langouche; S. Olafsson; Th. Aigne

    Mössbauer measurements have been performed on a GaAs single crystal sample following the implantation of radioactive 57Mn?+? ($T_{{\\\\raise0.7ex\\\\hbox{$T_{{\\\\raise0.7ex\\\\hbox{ min) ions. The Mn?+? ions were implanted with 60 keV energy into a GaAs sample held at temperatures of 300–700 K in an implantation chamber. Implantation\\u000a fluences were 12 ions\\/cm2 which assured single ion implantations. Mössbauer spectra were measured with a resonance detector equipped with

  6. Tooth movements are guided by specific contact areas between the tooth root and the jaw bone: A dynamic 3D microCT study of the rat molar.

    PubMed

    Naveh, Gili R S; Shahar, Ron; Brumfeld, Vlad; Weiner, Steve

    2012-02-01

    Teeth sustain high loads over a lifetime and yet intact tooth failure is rare. The different structures of the tooth, jaw bone and the intervening soft periodontal ligament enable the tooth to endure repeated loading during mastication. Although mechanical and functional properties of the different components are thoroughly investigated, the manner in which the whole tooth functions under load is still enigmatic. A custom-made loading system inside a microCT scanner was used to directly visualize the root movements in relation to the jaw bone as the rat molar tooth was loaded. At low loads no contact was observed between the root surface and the bone, whereas at higher loads three specific contact areas between the root surface and the jaw bone were observed. These contact areas restrict tooth movement in the buccal-lingual direction, but enable the tooth to rock in a "seesaw" like manner in the distal-mesial direction. The contact areas appear to play a role in determining tooth motion and in turn define the manner in which the whole tooth moves when loaded. These observations are important for understanding basic structure-function relations of the tooth-PDL-bone system, and have direct implications for better understanding pathological and therapeutic processes in orthodontics, periodontics and jaw bone regeneration. PMID:22138090

  7. Transvenous defibrillator implantation in a patient with persistent left superior vena cava.

    PubMed

    Vijayvergiya, Rajesh; Shrivastava, Smit; Kumar, Alok; Otaal, Parminder S

    2013-04-26

    Persistent left superior vena cava (LSVC) can be incidentally detected during pacemaker implantation through left pectoral side. There is technical difficulty of optimal site pacing and lead stability for right ventricle lead in such situation. We hereby report a case of successful single-chamber implantable cardioverter defibrillator (ICD) implantation in a 50 years-old male with LSVC. The practical issues related with right ventricle lead implantation and pacing/defibrillation parameters for ICD device are discussed. PMID:23675558

  8. Transvenous defibrillator implantation in a patient with persistent left superior vena cava

    PubMed Central

    Vijayvergiya, Rajesh; Shrivastava, Smit; Kumar, Alok; Otaal, Parminder S

    2013-01-01

    Persistent left superior vena cava (LSVC) can be incidentally detected during pacemaker implantation through left pectoral side. There is technical difficulty of optimal site pacing and lead stability for right ventricle lead in such situation. We hereby report a case of successful single-chamber implantable cardioverter defibrillator (ICD) implantation in a 50 years-old male with LSVC. The practical issues related with right ventricle lead implantation and pacing/defibrillation parameters for ICD device are discussed. PMID:23675558

  9. Heat shock protein 27 R127W mutation: evidence of a continuum between axonal Charcot–Marie–Tooth and distal hereditary motor neuropathy

    Microsoft Academic Search

    Paolo Solla; Alessandro Vannelli; Alessandra Bolino; Giovanni Marrosu; Silvia Coviello; Maria Rita Murru; Stefania Tranquilli; Daniela Corongiu; Sara Benedetti; Maria Giovanna Marrosu

    2010-01-01

    BackgroundHeat shock protein 27 (HSP27) mutations have been reported to cause both Charcot-Marie-Tooth disease (CMT) type 2F and distal hereditary motor neuropathy (dHMN) although never previously in a single family.ObjectiveTo analyse clinical and electrophysiological findings obtained in a single large Sardinian family bearing the HSP27 R127W mutation.MethodsTwenty-one members of a five generation Sardinian family have been studied, including thirteen members

  10. Novel variable-tooth-thickness hob for longitudinal crowning in the gear-hobbing process

    Microsoft Academic Search

    Ruei-Hung Hsu; Zhang-Hua Fong

    2011-01-01

    In the gear-hobbing process, the work gear tooth flank is usually longitudinally crowned by varying the center distance between the hob and the work gear. Without crossed angle compensation, however, this center distance variation produces a twisted tooth flank on the workgear. This paper therefore proposes a methodology to reduce this tooth flank twist in longitudinal crowning by modifying the

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

    E-print Network

    Gilbert, Pupa Gelsomina De Stasio

    The grinding tip of the sea urchin tooth exhibits exquisite control over calcite crystal, 2009 (received for review October 13, 2008) The sea urchin tooth is a remarkable grinding tool. Even in the field of biomin- eralization is the ability of the sea urchin tooth to grind down limestone, because

  12. Facial nerve stimulation with cochlear implantation. VA Cooperative Study Group on Cochlear Implantation.

    PubMed

    Niparko, J K; Oviatt, D L; Coker, N J; Sutton, L; Waltzman, S B; Cohen, N L

    1991-06-01

    The course of the facial nerve may place it within the current field generated by an activated cochlear implant to produce incidental facial movement. We investigated the presence of facial nerve stimulation associated with cochlear implants in the VA Cooperative Study of Advanced Cochlear implants. Twelve of 82 patients enrolled in this study demonstrated facial nerve stimulation within 2 years of implant activation. Facial nerve stimulation in six patients with multiple channel implants (Nucleus or ineraid devices) either resolved spontaneously (n = 2), or was eliminated by deactivating basal (n = 2) or apical (n = 2) electrodes. Two of six patients with single-channel electrodes (3-M/Vienna devices) demonstrated facial nerve stimulation that resolved spontaneously (n = 2), resolved with lowering current output (n = 2), or was refractory to processor adjustment (n = 2). Intraoperative assessment in one of the refractory cases indicated that facial nerve stimulation resulted from current spread through the modiolus to activate the facial nerve. A variety of factors, including implant design, stimulus parameters, and local tissue impedances, may interact to produce incidental facial stimulation. Low-impedance pathways between the scala tympani and the modiolus may deserve increased recognition as an interactive factor in cochlear implant performance. PMID:1908975

  13. Arsenic-implanted polysilicon layers

    NASA Astrophysics Data System (ADS)

    Ryssel, H.; Iberl, H.; Bleier, M.; Prinke, G.; Haberger, K.; Kranz, H.

    1981-03-01

    The diffusion behavior of implanted arsenic in polycrystalline silicon was investigated, using backscattering and electrical measurements. The diffusion coefficient is D=8.5×10-3 exp (-2.74/kT) for polycrystalline silicon deposited on freshly-etched silicon and D=1.66 exp (-3.22/kT) for the deposition on silicon having natural oxide. At the interface to the single-crystalline silicon, a pile-up of arsenic occurs, which depends also on the surface treatment prior to the deposition of the polycrystalline silicon.

  14. Use of intraoral welding to stabilize dental implants in augmented sites for immediate provisionalization: a case report.

    PubMed

    Avvanzo, Pierluigi; Fabrocini, Lelio A; Ciavarella, Domenico; Avvanzo, Andrea; Lo Muzio, Lorenzo; De Maio, Raffaele A

    2012-02-01

    Immediate implant rehabilitation of edentulous arches may be somewhat problematic because of anatomic situations involving insufficient bone thickness or height and tooth position. The aim of this report was to present a retrospective case series of dental implants placed into augmented sites (split crest or sinus augmentation) that were stabilized with an intraorally welded framework at the time of immediate provisionalization. An intraoral welding unit was used to join and stabilize implants as an orthopedic splint to break down forces applied on provisional restorations during healing and osseointegration. This approach allows for the immediate provisionalization of implants in bone-defective areas where multiple implant systems have been enacted. Forty-eight implants in 16 patients were inserted, welded together to a titanium framework, and immediately provisionalized during the same surgery in which split-crest or sinus augmentation procedures were performed. After removing the welded frameworks, 1 of 48 implants failed; the failed implant was associated with a sinus augmentation procedure. Intraoral welding stabilization may be a predictable procedure to allow immediate loading in augmented areas during healing time and to stabilize implants against nonaxial forces, thereby reducing the number of surgical and prosthetic sessions and making patients comfortable and accustomed to immediate fixed provisional and definitive restorations. PMID:20932150

  15. Guided tissue regeneration ensures osseointegration of dental implants placed into extraction sockets. An experimental study in monkeys.

    PubMed

    Warrer, L; Gotfredsen, K; Hjørting-Hansen, E; Karring, T

    1991-01-01

    The aim of the present study was to explore the possibility of achieving osseointegration of dental titanium implants, inserted into alveoli immediately after tooth extraction, by covering the recipient site with a teflon membrane. In each of 7 monkeys, mucoperiosteal flaps were raised on the buccal and palatal aspects of the maxillary molars in both sides of the jaw. The second molars were then extracted and self tapping titanium implants of the screw type (Astra Dental Implants) were inserted into the sockets of the largest roots. In the coronal portion of the sockets, a void was always present between the implant and the socket walls. In one side of the jaw, a membrane (Gore-Tex Augmentation Material) was adjusted to cover the implant. The implant in the other side of the jaw served as control and was only covered by the tissue flaps. Microscopic analysis after 3 months of healing revealed that soft tissue was facing the coronal portion of the implants to a varying degree in the control side, while osseointegration was consistently observed to the top of the membrane-covered implants which remained submerged throughout the experimental period. The results suggest that the membrane technique can secure complete osseointegration of implants inserted immediately into extraction sockets. PMID:8597618

  16. Ion Implantation with Scanning Probe Alignment

    SciTech Connect

    Persaud, A.; Liddle, J.A.; Schenkel, T.; Bokor, J.; Ivanov, Tzv.; Rangelow, I.W.

    2005-07-12

    We describe a scanning probe instrument which integrates ion beams with the imaging and alignment function of a piezo-resistive scanning probe in high vacuum. The beam passes through several apertures and is finally collimated by a hole in the cantilever of the scanning probe. The ion beam spot size is limited by the size of the last aperture. Highly charged ions are used to show hits of single ions in resist, and we discuss the issues for implantation of single ions.

  17. Periapical lucency around the tooth: radiologic evaluation and differential diagnosis.

    PubMed

    Chapman, Margaret N; Nadgir, Rohini N; Akman, Andrew S; Saito, Naoko; Sekiya, Kotaro; Kaneda, Takashi; Sakai, Osamu

    2013-01-01

    Periapical lucencies are often seen incidentally at head and neck imaging studies performed for indications not related to the teeth. These lesions are, however, occasionally manifestations of diseases that have a wide range of effects and may at times represent the source of symptoms that prompted the study. The vast majority of periapical lucencies are the result of apical periodontal or pulpal disease. If found in an advanced state or left untreated, disease related to the tooth may spread to adjacent tissues, including the sinuses, orbits, deep fascial spaces of the neck, and intracranial structures, and result in a significant increase in patient morbidity and mortality. Although the majority of periapical lucencies seen on radiographs and computed tomographic images occur secondary to apical periodontal or pulpal disease, not all lucencies near the tooth root are due to infection. Lucency near the tooth root may be seen in the setting of other diseases of odontogenic and non-odontogenic origin, including neoplasms. Although imaging findings for these lesions can include periapical lucent components, awareness of the varied secondary imaging features can aid the radiologist in developing an accurate differential diagnosis. Familiarity with the imaging features and differential diagnoses of diseases or conditions that cause lucency around the tooth root results in appropriate referral and prompt diagnosis, management, and treatment, and can prevent unnecessary additional imaging or intervention. In addition, early recognition and appropriate treatment of infectious processes will result in improved clinical outcomes and a decrease in morbidity and mortality. PMID:23322846

  18. REVIEW ARTICLE Fibroblast growth factor signaling in mammalian tooth

    E-print Network

    Klein, Ophir

    and odontoblasts, as well as in the development and homeostasis of the stem cell niche that fuels the continuously. Keywords Fibroblast growth factors Á Tooth development Á Adult stem cells Á Mouse Á Human Introduction by somatic stem cells that reside in the proximal portion of the incisor and give rise to the differentiated

  19. [Importance of muscular pathology in differential diagnosis of tooth pain].

    PubMed

    Godefroy, J N; Adam, V

    1989-12-01

    Pain can be something hazy and the way it occurs can make the practitioner doubt. Some toothaches are treated with root canal therapy or removal of the tooth (or teeth) when be etiology is myofacial pain dysfunction (MPD). This implies the need of a proper differential diagnosis between myofacial pain dysfunction and root canal pathology. PMID:2638756

  20. Patterns of tooth size variability in the dentition of primates

    Microsoft Academic Search

    Philip D. Gingerich; Margaret J. Schoeninger

    1979-01-01

    Published data on tooth size in 48 species of non-human pri- mates have been analyzed to determine patterns of variability in the primate dentition. Average coefficients of variation calculated for all species, with males and females combined, are greatest for teeth in the canine region. In- cisors tend to be somewhat less variable, and cheek teeth are the least variable.

  1. Dickkopf-1 in Craniofacial Bone and Tooth Development 

    E-print Network

    Rodgers, Anika Sarah

    2014-08-20

    Dickkopf-1 (Dkk1) is a potent inhibitor of the Wnt/?-catenin signaling pathway in both tooth and bone development. Deletion of the Dkk1 gene in mice leads to embryonic lethality, whereas transgenic mice over-expressing Dkk1 in mature osteoblasts...

  2. Characteristics of tooth for millimeter waves and their application

    Microsoft Academic Search

    N. Hoshi; Y. Nikawa; K. Kawai; S. Ebisu

    1997-01-01

    The complex permittivity of a tooth has been measured over the frequency range from 0.04 to 40 GHz. These measurements revealed that caries is affected by millimeter waves. This phenomenon has been confirmed by simulation and experiment. Furthermore, it is concluded that millimeter waves may be used for dental medical diagnosis as well as dental medical treatment

  3. Comparison of intermaxillary tooth size discrepancies among different malocclusion groups

    Microsoft Academic Search

    Qiong Nie; Jiuxiang Lin

    1999-01-01

    The purpose of this study was to determine whether there is a prevalent tendency for intermaxillary tooth size discrepancies among different malocclusion groups. This study consisted of 60 subjects who served as the normal occlusion group and 300 patients divided into 5 malocclusion groups (ie, Class I with bimaxillary protrusion, Class II Division 1, Class II Division 2, Class III,

  4. [Foreign body in the submandibular gland: a tooth extraction complication].

    PubMed

    Kara, Medine; Yaz?c?, ?brahim; Dereköy, Fevzi Sefa; Güçlü, O?uz

    2015-01-01

    The head and neck region includes many vital anatomic structures. So, diseases of this region may have a more morbid and mortal course compared to other anatomic regions. In this article, we report a patient showing various symptoms due to a suture needle which was left in the surgical region during the extraction of the left inferior molar tooth three years ago. PMID:26050862

  5. Assessment of the progression of tooth wear on dental casts.

    PubMed

    Vervoorn-Vis, G M G J; Wetselaar, P; Koutris, M; Visscher, C M; Evälahti, M; Ahlberg, J; Lobbezoo, F

    2015-08-01

    Many methods are available for the grading of tooth wear, but their ability to assess the progression of wear over time has not been studied frequently. The aim was to assess whether the occlusal/incisal grading scale of the Tooth Wear Evaluation System (TWES) was sensitive enough for the detection of tooth wear progression from 14 to 23 years of age. A total of 120 sets of dental casts were gathered from 40 people, of whom impressions were made at 14, 18 and 23 years. The TWES was used to assess loss of clinical crown height throughout the entire dentition. There was a significant difference in the TWES scores between the three age groups on all teeth (Friedman tests; P < 0·005 in all cases). Post hoc Wilcoxon tests revealed that the difference between the scores between 14 and 18 years and between 18 and 23 was significant for most teeth. It was concluded that the TWES is sensitive enough to detect changes in tooth wear over time. PMID:25752246

  6. Seal Out Tooth Decay: A Fact Sheet for Parents

    MedlinePLUS

    Seal Out Tooth Decay A Fact Sheet for Parents National Institute of Dental and Craniofacial Research What are dental sealants? Sealants are thin, plastic coatings painted on the chewing surfaces of the back teeth. Sealants are put on in dentists’ offices, clinics, and ...

  7. Colour and translucency of tooth-coloured orthodontic brackets

    Microsoft Academic Search

    Yong-Keun Lee

    SUMMARY The objective of this study was to determine the refl ected and transmitted colours and the diffuse light transmittance of tooth-coloured brackets. Four ceramic and four plastic brands were evaluated and fi ve brackets of each brand were tested. Refl ected colour and spectral refl ectance of the labial surface of the brackets were measured according to the Commission

  8. Hair keratin mutations in tooth enamel increase dental decay risk.

    PubMed

    Duverger, Olivier; Ohara, Takahiro; Shaffer, John R; Donahue, Danielle; Zerfas, Patricia; Dullnig, Andrew; Crecelius, Christopher; Beniash, Elia; Marazita, Mary L; Morasso, Maria I

    2014-12-01

    Tooth enamel is the hardest substance in the human body and has a unique combination of hardness and fracture toughness that protects teeth from dental caries, the most common chronic disease worldwide. In addition to a high mineral content, tooth enamel comprises organic material that is important for mechanical performance and influences the initiation and progression of caries; however, the protein composition of tooth enamel has not been fully characterized. Here, we determined that epithelial hair keratins, which are crucial for maintaining the integrity of the sheaths that support the hair shaft, are expressed in the enamel organ and are essential organic components of mature enamel. Using genetic and intraoral examination data from 386 children and 706 adults, we found that individuals harboring known hair disorder-associated polymorphisms in the gene encoding keratin 75 (KRT75), KRT75(A161T) and KRT75(E337K), are prone to increased dental caries. Analysis of teeth from individuals carrying the KRT75(A161T) variant revealed an altered enamel structure and a marked reduction of enamel hardness, suggesting that a functional keratin network is required for the mechanical stability of tooth enamel. Taken together, our results identify a genetic locus that influences enamel structure and establish a connection between hair disorders and susceptibility to dental caries. PMID:25347471

  9. [The implantable automatic defibrillator].

    PubMed

    Chauvin, M; Jesel, L; Douchet-Krebs, M P

    2004-11-01

    Technical advances in the design of implantable automatic defibrillators have been constant since the introduction of these devices in the mid 80s. The most obvious advance is the miniaturisation of the devices from which all components have benefited. The capacity of the batteries has improved inversely proportionally to their size, even if the longevity has not always lived up to expectations. The volumic energy of the condensers has improved and their technology also, and their size has decreased. Condensers are still usually made by the electrolytic/aluminium method but tantalum technology is bound to become more generalised because it presents so many advantages. Above all, the circuitry has benefited from the progress of micro-electronics, associating miniaturisation with an increase in more and more complex functions...but requiring more electrical current. Of these functions, algorithms to detect arrhythmias has reduced the number of inappropriate shocks but do not yet have excellent specificity either in single or in dual chamber sensing. Defibrillators incorporating a multisite anti-bradycardiac function are more and more popular because of the close relationship between cardiac failure and sudden death. PMID:15609913

  10. Retention of ion-implanted-xenon in olivine: Dependence on implantation dose

    NASA Technical Reports Server (NTRS)

    Melcher, C. L.; Tombrello, T. A.; Burnett, D. S.

    1982-01-01

    The diffusion of Xe in olivine, a major mineral in both meteorites and lunar samples, was studied. Xe ions were implanted at 200 keV into single-crystal synthetic-forsterite targets and the depth profiles were measured by alpha particle backscattering before and after annealing for 1 hour at temperatures up to 1500 C. The fraction of implanted Xe retained following annealing was strongly dependent on the implantation dose. Maximum retention of 100% occurred for an implantion dose of 3 x 10 to the 15th power Xe ions/sq cm. Retention was less at lower doses, with (approximately more than or = 50% loss at one hundred trillion Xe ions/sq cm. Taking the diffusion coefficient at this dose as a lower limit, the minimum activation energy necessary for Xe retention in a 10 micrometer layer for ten million years was calculated as a function of metamorphic temperature.

  11. Bioceramics for implant coatings

    Microsoft Academic Search

    Allison A Campbell

    2003-01-01

    During the past century, synthetic materials and devices have been developed to the point at which they can be used successfully to replace and\\/or restore function to diseased or damaged tissues. In the field of orthopedics, the use of metal implants has significantly improved the quality of life for countless individuals. Critical factors for implant success include proper design, material

  12. Chemotherapeutics in implant dentistry.

    PubMed

    Zablotsky, M H

    1993-01-01

    Adjunctive treatment with various chemotherapeutic regimens in implant dentistry are reviewed along with the indications for specific approaches. The use of systemic antibiotics, topical antimicrobials, and various mechanical modalities are discussed in relation to patient maintenance and the repair of ailing implants. PMID:8358373

  13. Batteryless implanted echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K.

    1977-01-01

    Miniature ultrasonic echosonometer implanted within laboratory animals obtains energy from RF power oscillator that is electronically transduced via induction loop to power receiving loop located just under animal's skin. Method of powering device offers significant advantages over those in which battery is part of implanted package.

  14. Multichannel implantable telemetry system

    NASA Technical Reports Server (NTRS)

    Fryer, T. B.; Mccutcheon, E. P.; Sandler, H.; Freund, W.

    1977-01-01

    Multiplexed biotelemetry system for animal research combines several power-saving features. Implantable sensor measures up to eight parameters simultaneously, including blood flow. Microamp transistors, switching circuits, and CMOS technology are used to lower power requirements. However, when blood flow is monitored, these measures are insufficient to reduce power enough for long-term operation from implantable primary battery.

  15. Assignment of a second Charcot-Marie-Tooth type II locus to chromosome 3q

    SciTech Connect

    Kwon, J.M.; Elliott, J.L.; Yee, W.C. [Washington Univ. School of Medicine, St. Louis, MO (United States)] [and others

    1995-10-01

    Charcot-Marie-Tooth disease (CMT) is the most common inherited motor and sensory neuropathy. The neuronal form of this disorder is referred to as Charcot-Marie-Tooth type II disease (CMT2). CMT2 is usually inherited as an autosomal dominant trait with a variable age at onset of symptoms associated with progressive axonal neuropathy. In some families, the locus that predisposes to CMT2 has been demonstrated to map to the distal portion of the short arm of chromosome 1. Other families with CMT2 do not show linkage with 1p markers, suggesting genetic heterogeneity in CMT2. We investigated linkage in a single large kindred with autosomal dominant CMT2. The gene responsible for CMT2 in this kindred (CMT2B) was mapped to the interval between the microsatellite markers D3S1769 and D3S1744 in the 3q13-22 region. Study of additional CMT2 kindreds should serve to further refine the disease gene region and may ultimately lead to the identification of a gene defect that underlies the CMT2 phenotype. 21 refs., 3 figs., 1 tab.

  16. Biochemical comparison of plaque fluid on tooth and acrylic surfaces during a sucrose challenge.

    PubMed

    Rankine, C A; Smith, S L; Schneider, P E; Gardiner, D M

    1996-07-01

    Previous studies have investigated variations in dental plaque fluid composition within a single mouth after a sucrose exposure. The purpose of this study was to determine a potential source of calcium and phosphorus in plaque by comparing the pH, calcium and phosphorus concentrations in plaque fluid obtained from an acrylic appliance with samples taken from supragingival tooth surfaces within the same individual after a sucrose challenge. Separate plaque samples from 14 individuals were collected from an acrylic appliance or tooth surfaces within same individual before and 15 min after a 20% sucrose rinse. Each plaque sample was centrifuged and nanolitre samples of plaque fluid were analysed for pH with a pH microelectrode, for total calcium concentration by atomic absorption in a graphite furnace, and for phosphorus concentration by spectrophotometry. There was an increase in the calcium and phosphorus concentration in the plaque after the sucrose challenge and a significant increase in calcium and phosphorus concentrations in the plaque taken from the teeth compared to the acrylic surfaces. The results indicate that the increased total calcium and phosphorus in plaque during a sucrose challenge is probably derived from the demineralization of enamel or extracellular demineralized components. PMID:9015571

  17. Development of In Vivo Tooth EPR for Individual Radiation Dose Estimation and Screening

    PubMed Central

    Williams, Benjamin B.; Dong, Ruhong; Kmiec, Maciej; Burke, Greg; Demidenko, Eugene; Gladstone, David; Nicolalde, Roberto J; Sucheta, Artur; Lesniewski, Piotr; Swartz, Harold M

    2009-01-01

    The development of in vivo EPR has made it feasible to perform tooth dosimetry measurements in situ, greatly expanding the potential for using this approach for immediate screening after radiation exposures. The ability of in vivo tooth dosimetry to provide estimates of absorbed dose has been established through a series of experiments using unirradiated volunteers with specifically irradiated molar teeth placed in situ within gaps in their dentition and in natural canine teeth of patients who have completed courses of radiation therapy for head and neck cancers. Multiple measurements in patients who have received radiation therapy demonstrate the expected heterogeneous dose distributions. Dose response curves have been generated using both populations and, using the current methodology and instrument, the standard error of prediction based on single 4.5 minute measurements is approximately 1.5 Gy for inserted molar teeth and between 2.0 and 2.5 Gy in the more irregularly shaped canine teeth. Averaging of independent measurements can reduce this error significantly to values near 1 Gy. Developments to reduce these errors are underway, focusing on geometric optimization of the resonators, detector positioning techniques, and optimal data averaging approaches. In summary, it seems plausible that the EPR dosimetry techniques will have an important role in retrospective dosimetry for exposures involving large numbers of individuals. PMID:20065702

  18. Development of scanning measurement of tooth flankform of generated face mill hypoid gear pair with reference to the conjugate mating tooth flank form using 2 axes sensor

    Microsoft Academic Search

    Ryohei Takeda; Masaharu Komori

    2011-01-01

    The three diamensional (3D) scanning measurement method of tooth flank form of generated face mill gear pair is proposed,\\u000a which is based on the conjugate mating tooth flank form. In this method, deviation sensor is placed at the position which\\u000a has certain offset from the gear axis and synchronized to the gear rotation. This method realizes the 3D tooth flank

  19. Selfprotective smart orthopedic implants.

    PubMed

    Parvizi, Javad; Antoci, Valentin; Hickok, Noreen J; Shapiro, Irving M

    2007-01-01

    In this review, we discuss current advances leading to an exciting change in implant design for orthopedic surgery. The initial biomaterial approaches in implant design are being replaced by cellular-molecular interactions and nanoscale chemistry. New designs address implant complications, particularly loosening and infection. For infection, local delivery systems are an important first step in the process. Selfprotective 'smart' devices are an example of the next generation of orthopedic implants. If proven to be effective, antibiotics or other active molecules that are tethered to the implant surface through a permanent covalent bond and tethering of antibiotics or other biofactors are likely to transform the practice of orthopedic surgery and other medical specialties. This new technology has the potential to eliminate periprosthetic infection, a major and growing problem in orthopedic practice. PMID:17187471

  20. Dental patterning in the earliest sharks: Implications for tooth evolution.

    PubMed

    Maisey, John G; Turner, Susan; Naylor, Gavin J P; Miller, Randall F

    2014-05-01

    Doliodus problematicus is the oldest known fossil shark-like fish with an almost intact dentition (Emsian, Lower Devonian, c. 397Ma). We provide a detailed description of the teeth and dentition in D. problematicus, based on tomographic analysis of NBMG 10127 (New Brunswick Museum, Canada). Comparisons with modern shark dentitions suggest that Doliodus was a ram-feeding predator with a dentition adapted to seizing and disabling prey. Doliodus provides several clues about the early evolution of the "shark-like" dentition in chondrichthyans and also raises new questions about the evolution of oral teeth in jawed vertebrates. As in modern sharks, teeth in Doliodus were replaced in a linguo-labial sequence within tooth families at fixed positions along the jaws (12-14 tooth families per jaw quadrant in NBMG 10127). Doliodus teeth were replaced much more slowly than in modern sharks. Nevertheless, its tooth formation was apparently as highly organized as in modern elasmobranchs, in which future tooth positions are indicated by synchronized expression of shh at fixed loci within the dental epithelium. Comparable dental arrays are absent in osteichthyans, placoderms, and many "acanthodians"; a "shark-like" dentition, therefore, may be a synapomorphy of chondrichthyans and gnathostomes such as Ptomacanthus. The upper anterior teeth in Doliodus were not attached to the palatoquadrates, but were instead supported by the ethmoid region of the prechordal basicranium, as in some other Paleozoic taxa (e.g., Triodus, Ptomacanthus). This suggests that the chondrichthyan dental lamina was originally associated with prechordal basicranial cartilage as well as jaw cartilage, and that the modern elasmobranch condition (in which the oral dentition is confined to the jaws) is phylogenetically advanced. Thus, oral tooth development in modern elasmobranchs does not provide a complete developmental model for chondrichthyans or gnathostomes. PMID:24347366

  1. A clinical investigation of the efficacy of a tooth-whitening gel.

    PubMed

    Sielski, Chester; Conforti, Nicholas; Stewart, Bernal; Chaknis, Pat; Petrone, Margaret E; DeVizio, William; Volpe, Anthony R; Proskin, Howard M

    2003-08-01

    The objective of this randomized, controlled, examiner-blind, parallel-group clinical study was to determine whether a tooth-whitening gel (Colgate Simply White Night Clear Whitening Gel) can significantly lighten teeth when used once daily at night, as compared with a commercially available dentifrice. Following a baseline tooth shade evaluation using the VITA Shade Guide, qualifying adult male and female subjects from the Buffalo, New York area were randomized into 2 treatment groups, which were balanced for baseline VITA Shade Guide scores, gender, and age. The treatment groups were: (1) a commercially available dentifrice only; and (2) a tooth-whitening gel in addition to a commercially available dentifrice. Subjects assigned to the 2 groups were given the dentifrice and a soft-bristled toothbrush. In addition, subjects in one of the groups were given the tooth-whitening gel. All subjects were instructed to brush their teeth for 1 minute twice daily (morning and evening) with the dentifrice. The subjects in the group also using the tooth-whitening gel were further instructed to apply the gel once daily at night, as per manufacturer instructions. Evaluations of tooth shade for each subject were repeated after 2 weeks, and again after 3 weeks of product use. In addition, evaluations of tooth shade for subjects using the tooth-whitening gel were later conducted at 6 months after product use. Seventy-five subjects complied with the protocol and completed the study. At the 2-week and 3-week examinations, subjects using the tooth-whitening gel and dentifrice exhibited statistically significant (P < .05) tooth shade lightening relative to baseline tooth shade. Furthermore, at the 2-week and 3-week examinations, subjects using the tooth-whitening gel exhibited statistically significant (P < .05) tooth shade lightening relative to subjects using only the dentifrice. In addition, the 6-month-postuse examination showed that subjects using the tooth-whitening gel exhibited statistically significant (P < .05) tooth shade lightening relative to baseline, thereby maintaining the tooth shade lightening that was evident at 3 weeks. The results of this clinical study indicate that after once-daily use at night for 2 or 3 weeks, the tooth-whitening gel provided statistically significant tooth shade lightening relative to baseline tooth shade for up to at least 6 months and also provided statistically significant tooth shade lightening relative to a commercially available dentifrice after 2 and 3 weeks of product use. PMID:14692166

  2. A flexible target chamber for a varian 350 DF implanter

    NASA Astrophysics Data System (ADS)

    Kluge, Andreas; Ryssel, Heiner; Schork, Rainer

    1989-02-01

    The Varian 350 DF has a dual end Station. One of these stations can be equipped with an experimental implantation chamber allowing implants of up to 100 mm wafers. In order to allow for more flexible implants, especially for nonsemiconductor samples, a versatile chamber with a variety of different sample holders was built. The maximum sample size is 150 mm in diameter. For low implantation temperatures, down to 77 K, a cooled cube is used and four semiconductor samples can be accommodated. A different sample holder allows hot implants of single wafers up to 1000°C, e.g. for SOI implants. Since the time to reach the equilibrium temperature is of the order of 1 s, this holder can also be used for rapid thermal annealing after implantation. Low-energy implants can be performed by applying a bias to an insulated target holder. Experiments down to 2 keV were performed. Applications in the field of surface treatment of metals are possible using two other sample holders which allow the implantation of cylinders or ball-bearing races.

  3. Unilateral single-rooted primary mandibular first molar.

    PubMed

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  4. Unilateral single-rooted primary mandibular first molar

    PubMed Central

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  5. Immune tolerance of mice allogenic tooth transplantation induced by immature dendritic cells

    PubMed Central

    Li, Wenying; Deng, Feng; Wang, Yu; Ma, Ce; Wang, Yurong

    2015-01-01

    As a common procedure in dentistry for replacing a missing tooth, allogenic tooth transplantation has encountered many difficulties in the clinical application because of immunological rejection. It is hypothesized that immature dendritic cell injection might be a potential alternative method to avoid or alleviate immunological rejection in allogenic tooth transplantation. To test this hypothesis, a mouse model of allogenic and autogeneic tooth transplantation was to established test the immunosuppressive effect of immature dendritic cells (imDCs) derived from donor bone marrows on transplant rejection in allogenic tooth transplantation. 2 × 106 imDCs generated with 50 U/ml GM-CSF were injected to each recipient mouse by two ways: tail vein injection 7 days before transplantation or regional dermal injection at day 0 and day 3 after transplantation. Groups of autogeneic tooth transplantation and allogenic tooth transplantation without any treatment were set as control groups. The effects were evaluated with histopathology and immunohistochemistry. We found there was no obvious rejection in autogeneic tooth transplantation group; tail intravenous injection group showed obviously alleviated rejection while local injection group and none-treatment allogenic tooth transplantation group both showed severe rejection. Our results suggested that the rejection of allogenic tooth transplantation could be alleviated by tail vein injection of donor bone marrow-derived imDCs though it could not be completely eliminated. The clinical application of imDCs in allogenic tooth transplantation still needs further deep research.

  6. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants

    NASA Astrophysics Data System (ADS)

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Engin Vrana, Nihal

    2015-05-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 ?m in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell-laden gelatin hydrogels, significantly more cells migrated towards the acid etched beads. In conclusion, the nanoscale surface treatment of 3D porous titanium structures can modulate in vivo integration by the accumulative effect of the surface treatment on several physical factors such as protein adsorption, surface hydrophilicity and surface roughness. The improved protein adsorption capacity of the treated implants can be further exploited by a pre-treatment with autologous serum to render the implant surface more bioactive. Titanium microbeads are a good model system to observe these effects in a 3D microenvironment and provide a better representation of cellular responses in 3D.Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 ?m in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin

  7. Radiopaque dental impression method for radiographic interpretation, digital alignment, and surgical guide fabrication for dental implant placement.

    PubMed

    Scherer, Michael D; Roh, Hyun Ki

    2015-04-01

    Adequate visualization of existing/proposed tooth position, denture base contours, and prosthetic space is critical to treatment planning of dental implants. Multiple techniques exist for fabricating radiographic guides; many involve duplicating the patient's existing prosthesis or fabricating a new diagnostic template. This article describes a technique that provides anatomic and restorative information by using an existing prosthesis and a radiographic impression method without the need to fabricate a duplicate or new template. PMID:25702970

  8. Thin film multiferroic nanocomposites by ion implantation.

    PubMed

    Algueró, Miguel; Ricote, Jesús; Torres, María; Amorín, Harvey; Alberca, Aurora; Iglesias-Freire, Oscar; Nemes, Norbert; Holgado, Susana; Cervera, Manuel; Piqueras, Juan; Asenjo, Agustina; García-Hernández, Mar

    2014-02-12

    Thin film multiferroic nanocomposites might enable a range of potentially disruptive integrated magnetoelectric devices for information storage, spintronics, microwave telecommunications, and magnetic sensing. With this aim, we have investigated ion implantation of magnetic species into ferroelectric single crystal targets as a radically novel approach to prepare film nanoparticulate magnetic-metal ferroelectric-oxide composites. These materials are an alternative to multiferroic oxide epitaxial columnar nanostructures that are under intensive research, but whose magnetoelectric response is far from expectations. Here, we unambiguously demonstrate the preparation of such a thin film multiferroic nanocomposite of Co and BaTiO3 by ion implantation of a high dose of the magnetic species, followed by rapid thermal processing under tailored conditions. Results thus constitute a proof of concept for the feasibility of obtaining the materials by this alternative approach. Ion implantation is a standard technique for the microelectronic industry in combination with well-established patterning procedures. PMID:24417708

  9. Inexpensive cochlear implant device.

    PubMed

    Kanchanarak, C; Siriratwatanakul, N; Boonyanukul, S; Saeng-in, A; Krairojananan, T

    1991-12-01

    We have developed a cochlear implant (CI) device modified from the House/3M cochlear implant device. The cost of raw materials was about $25. We used a new and simple technique for coating the implanted coil. We modified the circuit and removed the amplitude-modulated circuit. With this modification, the device uses less electricity and fewer transistors. There are slightly more than 3,000 patients using CI devices all over the world. Millions of profoundly deaf patients are poor and cannot afford the CI device that is now commercially available. Any university with well-trained otolaryngologists and physicists or electrical engineers can perform this technique. PMID:1746846

  10. Cost effectiveness of the multichannel cochlear implant.

    PubMed

    Wyatt, J R; Niparko, J K; Rothman, M L; deLissovoy, G

    1995-01-01

    Although most third-party payors presently fund cochlear implantation, some do not, and many cite the current lack of cost-effectiveness data as a major concern. Cost-utility analysis is a widely used method of medical technology assessment that permits cost-effectiveness comparisons between medical interventions by determining the cost per quality-adjusted life-year (QALY) they provide. The cost per QALY for the cochlear implant was determined using clinical cost data and a health-utility outcome model based on the established communication gains attained with the device. Cochlear implantation costs approximately $15,600 per QALY provided. Sensitivity analysis, a technique that systematically varies the assumptions underlying the calculations, favorably with other medical interventions, such as coronary artery bypass grafting ($10,431) for three-vessel disease, $64,033 for single-vessel disease), the implantable defibrillator ($29,200), and cardiac transplantation ($38,970). This analysis indicates that the cochlear implant lies well within the cost-effectiveness range currently accepted by the American medical system. PMID:8579178

  11. Ion implanted catalysts for fuel cell reactions

    NASA Astrophysics Data System (ADS)

    Wolf, Gerhard K.; Zucholl, K.; Folger, H.; O'Grady, W. E.

    1983-05-01

    The potential of ion implanted and ion beam mixed catalysts with respect to electrochemical reactions for fuel cells was studied. The catalysts were prepared by implanting platinum into graphite or ruthenium dioxide substrates, or by intermixing a 300 Å thick sputtered platinum layer with these substrates using an argon or krypton ion beam. Such dispersed systems are relatively stable against corrosion. It was shown that the activity of platinum, implanted in carbon, for the hydrogen redox-reaction was very low, that of ion beam mixed samples, rather high, as compared to smooth platinum. The implanted platinum was obviously buried in the bulk of the carbon substrate. Platinum implanted in RuO 2 was about as active for the formic acid oxidation as smooth platinum, but, unlike smooth platinum, completely inactive for the methanol oxidation. The same was true for the samples mixed with a krypton beam, at a high degree of intermixing. For low doses of intermixing Kr ions the behaviour was like that for smooth platinum. The results show that by ion beam techniques novel catalysts can be produced with unique features. The selectivity of these materials is explained in terms of differences in the adsorption properties of dispersed single atoms or small clusters, and big clusters or smooth platinum respectively, with regard to the different electrochemical reactions studied.

  12. Speech and Literacy Development in a Child with a Cochlear Implant: Application of a Psycholinguistic Framework

    ERIC Educational Resources Information Center

    Pascoe, Michelle; Randall-Pieterse, Candice; Geiger, Martha

    2013-01-01

    This single case study describes the speech, phonological awareness and literacy of a 6;0-year-old girl with a cochlear implant. NG, a child with a congenital bilateral severe/profound hearing loss, received a monaural cochlear implant at the age of 3;0, three years prior to the study. Using a psycholinguistic framework to investigate her single

  13. Ion implantation at elevated temperatures

    SciTech Connect

    Lam, N.Q.; Leaf, G.K.

    1985-11-01

    A kinetic model has been developed to investigate the synergistic effects of radiation-enhanced diffusion, radiation-induced segregation and preferential sputtering on the spatial redistribution of implanted solutes during implantation at elevated temperatures. Sample calculations were performed for Al and Si ions implanted into Ni. With the present model, the influence of various implantation parameters on the evolution of implant concentration profiles could be examined in detail.

  14. Implant treatment planning: endodontic considerations.

    PubMed

    Simonian, Krikor; Frydman, Alon; Verdugo, Fernando; Roges, Rafael; Kar, Kian

    2014-12-01

    Implants are a predictable and effective method for replacing missing teeth. Some clinicians have advocated extraction and replacement of compromised but treatable teeth on the assumption that implants will outperform endodontically and/or periodontally treated teeth. However, evidence shows that conventional therapy is as effective as implant treatment. With data on implants developing complications long term and a lack of predictable treatment for peri-implantitis, retaining and restoring the natural dentition should be the first choice when possible. PMID:25928961

  15. Method of fabricating optical waveguides by ion implantation doping

    DOEpatents

    Appleton, Bill R. (Oak Ridge, TN); Ashley, Paul R. (Toney, AL); Buchal, Christopher J. (Juelich, DE)

    1989-01-01

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO.sub.3 crystals are implanted with high concentrations of Ti dopant at ion energies of about 350 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000.degree. C. produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality single crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguides properties.

  16. Annealing behavior of cadmium ion implanted GaSb

    NASA Astrophysics Data System (ADS)

    Pandey, S. D.; Dubey, S. K.

    2013-02-01

    Single crystal, n-type GaSb substrates implanted with 300 keV cadmium ions at fluence 1×1016cm-2 have been investigated for their annealing behavior. The defect density in the implanted sample was estimated as 1.4×1018cm-3 indicating that cadmium ion implantation produces many defects in GaSb. FTIR studies before and after rapid thermal annealing showed recrystalization and reduction in defect levels. Reflection spectra showed oscillatory interference fringes for as-implanted sample which vanished with gradual rapid thermal annealing. The broadening of peak and reduction in its intensity observed in XRD spectra of as-implanted sample disappeared with progressive annealing.

  17. Optical and structural behaviour of Mn implanted sapphire

    NASA Astrophysics Data System (ADS)

    Marques, C.; Franco, N.; Kozanecki, A.; da Silva, R. C.; Alves, E.

    2006-09-01

    Sapphire single crystals were implanted at room temperature with 180 keV manganese ions to fluences up to 1.8 × 10 17 cm -2. The samples were annealed at 1000 °C in oxidizing or reducing atmosphere. Surface damage was observed after implantation of low fluences, the amorphous phase being observed after implantation of 5 × 10 16 cm -2, as seen by Rutherford backscattering spectroscopy under channelling conditions. Thermal treatments in air annealed most of the implantation related defects and promoted the redistribution of the manganese ions, in a mixed oxide phase. X-ray diffraction studies revealed the presence of MnAl 2O 4. On the contrary, similar heat treatments in vacuum led to enhanced out diffusion of Mn while the matrix remained highly damaged. The analysis of laser induced luminescence performed after implantation showed the presence of an intense red emission.

  18. Investigation of Carbon ion-implanted waveguides in tungsten bronze (Ca0.28Ba0.72)0.25(Sr0.6Ba0.4)0.75Nb2O6 single crystal

    NASA Astrophysics Data System (ADS)

    Jiao, Yang; Wang, Chuan-Kui; Li, Zong-Liang; Ren, Ying-Ying

    2014-09-01

    Planar optical waveguides were fabricated in (Ca0.28Ba0.72)0.25(Sr0.6Ba0.4)0.75Nb2O6 (CSBN25) crystal by 6.0-MeV C+ ion implantation with fluences of 2, 4 and 6 × 1014 ions/cm2 at room temperature. The mode parameters, refractive indices profiles are measured and the refractive indices behavior in the waveguide region is discussed. The shape of nuclear energy loss distribution of the C+ implantation was similar to those of the waveguide refractive index profiles, which means an inherent relationship between the waveguide formation and the energetic energy deposition. The extraordinary refractive index has a small positive change in the surface region after the implantation.

  19. Selective formation of metastable ferrihydrite in the chiton tooth.

    PubMed

    Gordon, Lyle M; Román, Jessica K; Everly, R Michael; Cohen, Michael J; Wilker, Jonathan J; Joester, Derk

    2014-10-20

    Metastable precursors are thought to play a major role in the ability of organisms to create mineralized tissues. Of particular interest are the hard and abrasion-resistant teeth formed by chitons, a class of rock-grazing mollusks. The formation of chiton teeth relies on the precipitation of metastable ferrihydrite (Fh) in an organic scaffold as a precursor to magnetite. In?vitro synthesis of Fh under physiological conditions has been challenging. Using a combination of X-ray absorption and electron paramagnetic resonance spectroscopy, we show that, prior to Fh formation in the chiton tooth, iron ions are complexed by the organic matrix. In?vitro experiments demonstrate that such complexes facilitate the formation of Fh under physiological conditions. These results indicate that acidic molecules may be integral to controlling Fh formation in the chiton tooth. This biological approach to polymorph selection is not limited to specialized proteins and can be expropriated using simple chemistry. PMID:25196134

  20. Regulated fracture in tooth enamel: a nanotechnological strategy from nature.

    PubMed

    Ghadimi, Elnaz; Eimar, Hazem; Song, Jun; Marelli, Benedetto; Ciobanu, Ovidiu; Abdallah, Mohamed-Nur; Stähli, Christoph; Nazhat, Showan N; Vali, Hojatollah; Tamimi, Faleh

    2014-07-18

    Tooth enamel is a very brittle material; however it has the ability to sustain cracks without suffering catastrophic failure throughout the lifetime of mechanical function. We propose that the nanostructure of enamel can play a significant role in defining its unique mechanical properties. Accordingly we analyzed the nanostructure and chemical composition of a group of teeth, and correlated it with the crack resistance of the same teeth. Here we show how the dimensions of apatite nanocrystals in enamel can affect its resistance to crack propagation. We conclude that the aspect ratio of apatite nanocrystals in enamel determines its resistance to crack propagation. According to this finding, we proposed a new model based on the Hall-Petch theory that accurately predicts crack propagation in enamel. Our new biomechanical model of enamel is the first model that can successfully explain the observed variations in the behavior of crack propagation of tooth enamel among different humans. PMID:24813507

  1. Beeswax as dental filling on a neolithic human tooth.

    PubMed

    Bernardini, Federico; Tuniz, Claudio; Coppa, Alfredo; Mancini, Lucia; Dreossi, Diego; Eichert, Diane; Turco, Gianluca; Biasotto, Matteo; Terrasi, Filippo; De Cesare, Nicola; Hua, Quan; Levchenko, Vladimir

    2012-01-01

    Evidence of prehistoric dentistry has been limited to a few cases, the most ancient dating back to the Neolithic. Here we report a 6500-year-old human mandible from Slovenia whose left canine crown bears the traces of a filling with beeswax. The use of different analytical techniques, including synchrotron radiation computed micro-tomography (micro-CT), Accelerator Mass Spectrometry (AMS) radiocarbon dating, Infrared (IR) Spectroscopy and Scanning Electron Microscopy (SEM), has shown that the exposed area of dentine resulting from occlusal wear and the upper part of a vertical crack affecting enamel and dentin tissues were filled with beeswax shortly before or after the individual's death. If the filling was done when the person was still alive, the intervention was likely aimed to relieve tooth sensitivity derived from either exposed dentine and/or the pain resulting from chewing on a cracked tooth: this would provide the earliest known direct evidence of therapeutic-palliative dental filling. PMID:23028670

  2. Corrosion of surgical implants.

    PubMed

    Traisnel, M; le Maguer, D; Hildebrand, H F; Iost, A

    1990-01-01

    Corrosion on orthopaedic implants has been studied. Twelve intramedullary nails and twelve osteosynthesis plates were implanted up to eight and thirteen years, respectively. Analysis of biological fluids from all patients was carried out and revealed high concentrations of nickel and chromium that correlated to the implantation time. All implants were corroded by both crevice and intergranular corrosion. Intergranular corrosion is related to mechanical and heating treatments. Crevice-like corrosion is probably enhanced by sulphur present in amino-acids. Electronic probe analysis shows the reaction study between both sulphur and nickel and sulphur and chromium. These results are compared to the metal distribution in body fluids. After a certain incubation time the corrosion accelerates as is characteristic for crevice-like corrosion processes. Studies of the distribution rate of two Ni-Fe-Cr dental alloys in a cell culture system give similar results: metal-ion release increases with the exposure time. PMID:10147509

  3. Cochlear implantation update.

    PubMed

    Francis, Howard W; Niparko, John K

    2003-04-01

    Cochlear implantation is recognized as a valuable intervention with important implications for the acquisition of speech perception and verbal language in children with severe to profound hearing impairment. Auditory rehabilitation, language intervention, and close coordination between parents, schools, and the implant center are necessary to maximize efficacy. Early identification of hearing loss, early hearing aid use and language intervention, and cochlear implantation by 2 years of age are positive predictors for language acquisition that can approach the levels of normal-hearing children. There are early indications that increased access to mainstream education and gains in quality of life are long-term benefits that render cochlear implantation a cost-effective intervention. PMID:12809327

  4. [Osteosynthesis using absorbable implants].

    PubMed

    Arva, G; Fröhlich, P

    1994-01-01

    Authors report on one case of malleolar synthesis with the use of biodegradable implants. The advantages of the resorbing osteosynthesis materials and the possible complications are described. PMID:8162144

  5. Negative-ion implantation

    SciTech Connect

    Ishikawa, Junzo [Kyoto Univ., Yoshida, Kyoto (Japan). Dept. of Electronics

    1995-12-31

    Negative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected without a charge neutralizer in these fabrication processes. Scatter-less negative-ion implantation into powders is also possible. For this purpose an rf-plasma-sputter type heavy negative-ion source was developed, which can deliver several milliamperes of various kinds of negative ion currents such as boron, phosphor, silicon, carbon, copper, oxygen, etc. A medium current negative-ion implanter with a small version of this type of ion source has been developed.

  6. Implant-Supported Bridge

    MedlinePLUS

    ... made by the dental lab. Porcelain-fused-to-metal bridge The restoration (the part that looks like ... porcelain attached and fused to a framework of metal. The Implant Process The time it takes to ...

  7. Relationship between Food Habits and Tooth Erosion Occurrence in Malaysian University Students

    PubMed Central

    Zahara, Abdul Manaf; Mei Tee, Lee; Nor Hazirah, Muhammad Ali; Selvamary, Samynathan; Ying Phor, Jie; Noor Hasnani, Ismail; Bibiana Hui Ying, Yong; Wei Seng, Yeo; Nurul Asyikin, Yahya

    2012-01-01

    Background: Tooth erosion is a growing dental problem; however, the role of diet in the aetiology of tooth erosion is unclear. A cross-sectional study was conducted to determine the association between tooth erosion occurrence and the consumption of acidic foods and drinks among undergraduate university students. Methods: A total of 150 undergraduate students (33 males and 117 females) aged 19 to 24 years at Universiti Kebangsaan Malaysia participated in this study. The Basic Erosive Wear Examination was used to assess the occurrence of tooth erosion. Information regarding dental hygiene practices, usual dietary habits, and consumption of acidic foods and drinks was obtained through a structured questionnaire. Results: In all, 68% of subjects had tooth erosion. Subjects who reported having received information about healthy eating were less likely to have tooth erosion (?2 [1, N = 150] = 7.328, P = 0.007). The frequencies of milk (OR = 0.29, 95% CI = 0.13–0.67) and tea/coffee (adjusted OR = 0.42, 95% CI = 0.19–0.95) consumption were negatively associated with tooth erosion. Dental hygiene practice, the frequency and amount of acidic food and drink intake, and body mass index classification were not significantly associated with the risk of tooth erosion (P > 0.05). Conclusion: A high prevalence of tooth erosion was observed among this group of students. Preventive measures, such as dietary advice and increased consumption of milk at a younger age, may reduce the occurrence of tooth erosion among this age group. PMID:22973138

  8. Defibrillator Function and Implantation

    Microsoft Academic Search

    Robert E. Eckart; Jane Chen; Laurence M. Epstein

    The development of the implantable cardioverter-defibrillator (ICD) is primarily the result of pioneering work by Michel Mirowski.\\u000a First-generation devices consisted of a large generator placed in an abdominal pocket capable only of high-energy shocks.\\u000a In the 25 years since the first implantation in humans (1), advances in technology have resulted in significantly smaller\\u000a devices, with sophisticated detection algorithms and tiered

  9. Histopathology of ossicular implants.

    PubMed

    Merchant, S N; Nadol, J B

    1994-08-01

    Ossicular and cortical bone grafts maintain their morphologic structure for long periods of time and show varying amounts of replacement of nonviable bone by new bone through a slow process of creeping substitution. Cartilage grafts develop chondromalacia, lose stiffness, and tend to be resorbed over time. Plastipore prostheses elicit foreign body giant cell responses with microscopic biodegradation of the implants. There is a great need for the study of well-documented human temporal bone cases with in situ ossicular implants. PMID:7984378

  10. Materials chemistry: A synthetic enamel for rapid tooth repair

    NASA Astrophysics Data System (ADS)

    Yamagishi, Kazue; Onuma, Kazuo; Suzuki, Takashi; Okada, Fumio; Tagami, Junji; Otsuki, Masayuki; Senawangse, Pisol

    2005-02-01

    The conventional treatment of dental caries involves mechanical removal of the affected part and filling of the hole with a resin or metal alloy. But this method is not ideal for tiny early lesions because a disproportionate amount of healthy tooth must be removed to make the alloy or resin stick. Here we describe a dental paste of synthetic enamel that rapidly and seamlessly repairs early caries lesions by nanocrystalline growth, with minimal wastage of the natural enamel.

  11. Contact microradiographic analysis of feline tooth resorptive lesions.

    PubMed

    Ohba, S; Kiba, H; Kuwabara, M; Yoshida, H; Koide, F; Takeishi, M

    1993-04-01

    Feline tooth resorptive lesions were studied using contact microradiographic analysis of ground sections. Contact microdiagram films were developed with a PIAS-imaging device, and decalcification patterns were evaluated, revealing a clear boundary between normal tissue and the resorptive area, which was different from the image of dental caries in humans. By contrasting analysis, decalcification signs appearing in human caries were not observed in feline resorptive lesions. PMID:8513019

  12. Herbivore tooth oxygen isotope compositions: Effects of diet and physiology

    Microsoft Academic Search

    Matthew J. Kohn; Margaret J. Schoeninger; John W. Valley

    1996-01-01

    The applicability of rapid and precise laser probe analysis of tooth enamel for ?18O has been verified, and the method has been applied to different modern herbivores in East Africa. Sampling and pretreatment procedures involve initial bleaching and grinding of enamel to <75 ?m, and elimination of adsorbed water and organic compounds with BrF5. Typical analytical reproducibilities for 0.5–2 mg

  13. Clinical and electrophysiological aspects of Charcot-Marie-Tooth disease

    Microsoft Academic Search

    D. Pareyson; V. Scaioli; M. Laurà

    2006-01-01

    Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous group of disorders sharing the same clinical phenotype, characterized\\u000a by distal limb muscle wasting and weakness, usually with skeletal deformities, distal sensory loss, and abnormalities of deep\\u000a tendon reflexes. Mutations of genes involved in different functions eventually lead to a length-dependent axonal degeneration,\\u000a which is the likely basis of the distal predominance of

  14. Clinical and Electrophysiological Aspects of Charcot-Marie-Tooth Disease

    Microsoft Academic Search

    D. Pareyson; V. Scaioli; M. Laurà

    2006-01-01

    Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous group of disorders sharing the same clinical phenotype, characterized by distal limb muscle wasting and weakness, usually with skeletal deformities, distal sensory loss, and abnormalities of deep tendon reflexes. Muta- tions of genes involved in different functions eventually lead to a length-dependent axonal degen- eration, which is the likely basis of the distal

  15. Performance of laser fluorescence at tooth surface and histological section

    Microsoft Academic Search

    Anahita Jablonski-Momeni; David N. J. Ricketts; Stefanie Rolfsen; Richard Stoll; Monika Heinzel-Gutenbrunner; Vitus Stachniss; Klaus Pieper

    2011-01-01

    This study aimed to evaluate a laser fluorescence device (the DIAGNOdent) and a visual classification system (ICDAS-II) for\\u000a occlusal caries diagnosis. It also aimed to determine whether fluorescence measurements taken at the tooth surface correlate\\u000a with the fluorescence measurements taken within the body of the lesion. The occlusal surfaces of 100 extracted permanent teeth\\u000a were examined using ICDAS-II and DIAGNOdent

  16. Unicuspid and bicuspid tooth crown formation in squamates.

    PubMed

    Handrigan, Gregory R; Richman, Joy M

    2011-12-15

    The molecular and developmental factors that regulate tooth morphogenesis in nonmammalian species, such as snakes and lizards, have received relatively little attention compared to mammals. Here we describe the development of unicuspid and bicuspid teeth in squamate species. The simple, cone-shaped tooth crown of the bearded dragon and ball python is established at cap stage and fixed in shape by the differentiation of cells and the secretion of dental matrices. Enamel production, as demonstrated by amelogenin expression, occurs relatively earlier in squamate teeth than in mouse molars. We suggest that the early differentiation in squamate unicuspid teeth at cap stage correlates with a more rudimentary tooth crown shape. The leopard gecko can form a bicuspid tooth crown despite the early onset of differentiation. Cusp formation in the gecko does not occur by the folding of the inner enamel epithelium, as in the mouse molar, but by the differential secretion of enamel. Ameloblasts forming the enamel epithelial bulge, a central swelling of cells in the inner enamel epithelium, secrete amelogenin at cap stage, but cease to do so by bell stage. Meanwhile, other ameloblasts in the inner enamel epithelium continue to secrete enamel, forming cusp tips on either side of the bulge. Bulge cells specifically express the gene Bmp2, which we suggest serves as a pro-differentiation signal for cells of the gecko enamel organ. In this regard, the enamel epithelial bulge of the gecko may be more functionally analogous to the secondary enamel knot of mammals than the primary enamel knot. PMID:21932327

  17. Canine tooth size and fitness in male mandrills ( Mandrillus sphinx)

    Microsoft Academic Search

    Steven R. Leigh; Joanna M. Setchell; Marie Charpentier; Leslie A. Knapp; E. Jean Wickings

    2008-01-01

    Sexual selection theory explains the evolution of exaggerated male morphologies and weaponry, but the fitness consequences of developmental and age-related changes in these features remain poorly understood. This long-term study of mandrill monkeys (Mandrillus sphinx) demonstrates how age-related changes in canine tooth weaponry and adult canine size correlate closely with male lifetime reproductive success. Combining long-term demographic and morphometric data

  18. Integration of High Dose Boron Implants--Modification of Device Parametrics through Implant Temperature Control

    SciTech Connect

    Schmeide, Matthias [Infineon Technologies Dresden GmbH, Koenigsbruecker Str. 180, D-01099 Dresden (Germany); Ameen, M. S.; Kondratenko, Serguei; Krimbacher, Bernhard; Reece, Ronald N. [Axcelis Technologies, Inc., 108 Cherry Hill Dr., Beverly, MA, 01915 (United States)

    2011-01-07

    In the present study, we have extended a previously reported 250 nm logic p-S/D implant (7 keV B 4.5x10{sup 15} cm{sup -2}) process matching exercise [5] to include wafer temperature, and demonstrate that matching can be obtained by increasing the temperature of the wafer during implant. We found that the high dose rate delivered by the single wafer implanter caused the formation of a clear amorphous layer, which upon subsequent annealing altered the diffusion, activation, and clustering properties of the boron. Furthermore, increasing the temperature of the wafer during the implant was sufficient to suppress amorphization, allowing profiles and device parameters to become matched. Figure 5 shows a representative set of curves indicating the cluster phenomena observed for the lower temperature, high flux single wafer implanter, and the influence of wafer temperature on the profiles. The results indicate the strong primary effect of dose rate in determining final electrical properties of devices, and successful implementation of damage engineering using wafer temperature control.

  19. Biocompatible implant surface treatments.

    PubMed

    Pattanaik, Bikash; Pawar, Sudhir; Pattanaik, Seema

    2012-01-01

    Surface plays a crucial role in biological interactions. Surface treatments have been applied to metallic biomaterials in order to improve their wear properties, corrosion resistance, and biocompatibility. A systematic review was performed on studies investigating the effects of implant surface treatments on biocompatibility. We searched the literature using PubMed, electronic databases from 1990 to 2009. Key words such as implant surface topography, surface roughness, surface treatment, surface characteristics, and surface coatings were used. The search was restricted to English language articles published from 1990 to December 2009. Additionally, a manual search in the major dental implant journals was performed. When considering studies, clinical studies were preferred followed by histological human studies, animal studies, and in vitro studies. A total of 115 articles were selected after elimination: clinical studies, 24; human histomorphometric studies, 11; animal histomorphometric studies, 46; in vitro studies, 34. The following observations were made in this review: · The focus has shifted from surface roughness to surface chemistry and a combination of chemical manipulations on the porous structure. More investigations are done regarding surface coatings. · Bone response to almost all the surface treatments was favorable. · Future trend is focused on the development of osteogenic implant surfaces. Limitation of this study is that we tried to give a broader overview related to implant surface treatments. It does not give any conclusion regarding the best biocompatible implant surface treatment investigated till date. Unfortunately, the eventually selected studies were too heterogeneous for inference of data. PMID:23059581

  20. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups

    PubMed Central

    Bala, Madhu; Goyal, Virender

    2014-01-01

    ABSTRACT Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton’s ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. Aim: To determine any difference in tooth size discrepancy in anterior as well as overall ratio in different malocclusions and comparison with Bolton’s study. Materials and methods: After measuring the teeth on all 100 patients, Bolton’s analysis was performed. Results were compared with Bolton’s means and standard deviations. The results were also subjected to statistical analysis. Results show that the mean and standard deviations of ideal occlusion cases are comparable with those Bolton but, when the mean and standard deviation of malocclusion groups are compared with those of Bolton, the values of standard deviation are higher, though the mean is comparable. How to cite this article: Hasija N, Bala M, Goyal V. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups. Int J Clin Pediatr Dent 2014;7(2):82-85. PMID:25356005

  1. Cracked tooth diagnosis and treatment: An alternative paradigm

    PubMed Central

    Mamoun, John S.; Napoletano, Donato

    2015-01-01

    This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth furcations, and root fractures. This article provides alternative definitions of terms such as cracked teeth, complete and incomplete fractures and crack lines, and explores the scientific rationale for dental terminology commonly used to describe cracked teeth, such as cracked tooth syndrome, structural versus nonstructural cracks, and vertical, horizontal, and oblique fractures. The article explains the advantages of high magnification loupes (×6–8 or greater), or the surgical operating microscope, combined with co-axial or head-mounted illumination, when observing teeth for microscopic crack lines or enamel craze lines. The article explores what biomechanical factors help to facilitate the development of cracks in teeth, and under what circumstances a full coverage crown may be indicated for preventing further propagation of a fracture plane. Articles on cracked tooth phenomena were located via a PubMed search using a variety of keywords, and via selective hand-searching of citations contained within located articles.

  2. Hunter-Schreger Band patterns in human tooth enamel

    PubMed Central

    Lynch, Christopher D; O’Sullivan, Victor R; Dockery, Peter; McGillycuddy, Catherine T; Sloan, Alastair J

    2010-01-01

    Using light microscopy, we examined Hunter-Schreger Band (HSB) patterns on the axial and occlusal/incisal surfaces of 160 human teeth, sectioned in both the buccolingual and mesiodistal planes. We found regional variations in HSB packing densities (number of HSBs per mm of amelodentinal junction length) and patterns throughout the crown of each class of tooth (maxillary and mandibular: incisor, canine, premolar, and molar) examined. HSB packing densities were greatest in areas where functional and occlusal loads are greatest, such as the occlusal surfaces of posterior teeth and the incisal regions of incisors and canines. From this it is possible to infer that the behaviour of ameloblasts forming enamel prisms during amelogenesis is guided by genetic/evolutionary controls that act to increase the fracture and wear resistance of human tooth enamel. It is suggested that HSB packing densities and patterns are important in modern clinical dental treatments, such as the bonding of adhesive restorations to enamel, and in the development of conditions, such as abfraction and cracked tooth syndrome. PMID:20579171

  3. Contemporary management of tooth replacement in the traumatized dentition

    PubMed Central

    Alani, Aws; Austin, Rupert; Djemal, Serpil

    2012-01-01

    Dental trauma can result in tooth loss despite best efforts at retaining and maintaining compromised teeth (Dent Traumatol, 24, 2008, 379). Upper anterior teeth are more likely to suffer from trauma, and their loss can result in significant aesthetic and functional problems that can be difficult to manage (Endod Dent Traumatol, 9, 1993, 61; Int Dent J 59, 2009, 127). Indeed, teeth of poor prognosis may not only present with compromised structure but trauma may also result in damage to the support tissues. Injury to the periodontium and alveolus can have repercussions on subsequent restorative procedures (Fig. 19). Where teeth are identified as having a hopeless prognosis either soon after the incident or at delayed presentation; planning for eventual tooth loss and replacement can begin at the early stages. With advances in both adhesive and osseointegration technologies, there are now a variety of options for the restoration of edentate spaces subsequent to dental trauma. This review aims to identify key challenges in the provision of tooth replacement in the traumatized dentition and outline contemporary methods in treatment delivery. PMID:22494549

  4. The first Neanderthal tooth found North of the Carpathian Mountains

    NASA Astrophysics Data System (ADS)

    Urbanowski, Miko?aj; Socha, Pawe?; D?browski, Pawe?; Nowaczewska, Wioletta; Sadakierska-Chudy, Anna; Dobosz, Tadeusz; Stefaniak, Krzysztof; Nadachowski, Adam

    2010-04-01

    An upper second permanent molar from a human was found alongside numerous tools of the Micoquian tradition and was excavated in Stajnia Cave, which is located over 100 km North of the Carpathian Mountains in southern Poland. The age of these finds has been established within a time-span of late Saalian to early Weichselian, most likely to OIS 5c or 5a, according to the palaeontological, geological, archaeological and absolute dating of the layer from which they were obtained. An examination of the morphology of the human molar indicates that this tooth exhibits many traits frequently occurring in Neanderthal upper molars. Although the occurrence of derived Neanderthal traits in the Stajnia molar cannot be firmly established because of degradation of its cusps, the presence of the above-mentioned features allows the assertion that this tooth belonged to a Neanderthal. The age of the Stajnia tooth and the archaeological context of this find also indicate that this molar is of Neanderthal origin.

  5. Cracked tooth diagnosis and treatment: An alternative paradigm.

    PubMed

    Mamoun, John S; Napoletano, Donato

    2015-01-01

    This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth furcations, and root fractures. This article provides alternative definitions of terms such as cracked teeth, complete and incomplete fractures and crack lines, and explores the scientific rationale for dental terminology commonly used to describe cracked teeth, such as cracked tooth syndrome, structural versus nonstructural cracks, and vertical, horizontal, and oblique fractures. The article explains the advantages of high magnification loupes (×6-8 or greater), or the surgical operating microscope, combined with co-axial or head-mounted illumination, when observing teeth for microscopic crack lines or enamel craze lines. The article explores what biomechanical factors help to facilitate the development of cracks in teeth, and under what circumstances a full coverage crown may be indicated for preventing further propagation of a fracture plane. Articles on cracked tooth phenomena were located via a PubMed search using a variety of keywords, and via selective hand-searching of citations contained within located articles. PMID:26038667

  6. A patient with both Charcot-Marie-Tooth disease (CMT 1A) and mild spinal muscular atrophy (SMA 3).

    PubMed

    Jedrzejowska, Maria; Ryniewicz, Barbara; Kabzi?ska, Dagmara; Drac, Hanna; Hausmanowa-Petrusewicz, Irena; Kocha?ski, Andrzej

    2008-04-01

    In the present study, we report a single Polish SMA family in which the 17p11.2-p12 duplication causative for the Charcot-Marie-Tooth type 1A disease (CMT1A) was found in addition to a deletion of exons 7 and 8 of the SMN1 gene. A patient harboring both SMA and CMT1A mutations manifested with SMA3 phenotype and foot deformity. Her electrophysiological testing showed chronic neurogenic changes in proximal muscles that are typical for SMA, but also slowed conduction velocity in motor and sensory fibers that is typical for demyelinating neuropathy. PMID:18337101

  7. Fully Implantable Blood Pressure System: Implantation Experiences

    Microsoft Academic Search

    U. Urban; R. Ballan; H. Fassbender; P. Fuerst; T. Goettsche; B. Bender; R. Becker; W. Mokwa; H. K. Trieu; P. Osypka; R. Glocker; U. Steinseifer; T. Schmitz-Rode

    \\u000a Hypertension is an important risk factor for vascular diseases (arteriosclerosis), renal and heart insufficiency. In Germany,\\u000a approximately 10 million people suffer from hypertension. 10% of the people affected are difficult to medicate. Furthermore,\\u000a 10% of this group are candidates for long term monitoring. Therefore a fully implantable and telemetrically controlled blood\\u000a pressure system is presented to realize a comfortable long

  8. Mild early onset axonal Charcot-Marie-Tooth disease not linked to other axonal Charcot-Marie-Tooth loci.

    PubMed

    Kochanski, A; Kennerson, M; Kawulak, M; Ryniewicz, B; Rowinska-Marcinska, K; Walizada, G; Nowakowski, A; Hausmanowa-Petrusewicz, I; Nicholson, G A

    2005-02-01

    Autosomal dominant axonal Charcot-Marie-Tooth disease type 2 (CMT2) is a heterogeneous group of disorders with seven chromosomal loci mapped in the uncomplicated forms of CMT2. The authors report clinical, electrophysiologic, and genetic analysis of a Polish CMT2 family. Nine known CMT2 gene loci and one MPZ gene locus have been excluded. The authors' findings suggest that this family represents a novel form of CMT2 disease. PMID:15699389

  9. Laser Additive Manufacturing of Modified Implant Surfaces with Osseointegrative Characteristics

    NASA Astrophysics Data System (ADS)

    Emmelmann, C.; Scheinemann, P.; Munsch, M.; Seyda, V.

    Additive Manufacturing technology, such as Selective Laser Melting, allows fabrication of complex metal parts with freeform surfaces. Using biocompatible metal alloys, e.g. TiAl6V4, medical implants can be produced. To increase osseointegrative behavior the ability to fabricate filigree lattice structures can be utilized to achieve a modified implant surface. In order to increase dimensional accuracy when applying a lattice structure on a curved surface, process constraints for single lattice bars are studied. The investigated lattice structure was thereupon applied on the surface of a medical implant.

  10. Ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M. (Albuquerque, NM); Hammons, Burrell E. (Tijeras, NM); Myers, David R. (Albuquerque, NM); Vawter, Gregory A. (Albuquerque, NM)

    1991-01-01

    A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding layer 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an ion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  11. Ion-implanted planar-buried-heterostructure diode laser

    SciTech Connect

    Brennan, T.M.; Hammons, B.E.; Myers, D.R.; Vawter, G.A.

    1991-09-10

    A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser is described that includes a single quantum well or multi-quantum well active stripe disposed between a p-type compositionally graded Group III-V cladding layer and an n-type compositionally graded Group III-V cladding layer. The laser 10 includes an ion implanted n-type region within the p-type cladding layer and further includes an ion implanted p-type region within the n-type cladding layer. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  12. Activation of ? 2 -adrenoreceptors suppresses the excitability of C1 spinal neurons having convergent inputs from tooth pulp and superior sagittal sinus in rats

    Microsoft Academic Search

    M. Takeda; T. Tanimoto; M. Takahashi; J. Kadoi; M. Nasu; S. Matsumoto

    2006-01-01

    The aim of the present study was to test the hypothesis that activation of ?2-adrenoreceptors modulates the excitability of C1 neurons having convergent inputs from both the tooth pulp (TP) and the superior sagittal sinus (SSS), by using the microiontophoretic techniques of drug application and immunohistochemical approaches. Extracellular single-unit recordings were made from 38 C1 neurons responding to electrical stimulation

  13. Black Carbon, Aerosols, and the Tooth Fairy

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Adachi, K.; Posfai, M.

    2012-12-01

    Black carbon (BC) is widely cited in the atmospheric literature as a major aerosol particle type with significant effects on climate warming. Several analytical techniques are used for its determination, primarily through optical absorption measurements. A recently developed and widely used method is single particle soot photometry (SP2). During attempts to obtain reliable BC samples for study using transmission electron microscopy (TEM), it became apparent that no such samples exist. Instead, surrogate materials such as graphite, fullerene, Aquadag, and perhaps other things are used as calibration standards. It became rapidly evident that BC is an inferred rather than actual, identifiable substance with distinct material properties other than its absorption spectrum and refractory character (accounting for the subset of refractory black carbon, or rBC). Since climate effects depend on optical properties, and these are estimated for BC, it may not be critical at this time whether or not it is a discrete material. However, the same term is also used by other environmental communities for things that are distinctly different. Such imprecision in terms can lead to unnecessary confusion. The situation is summarized in the Table. We propose that 1) the term BC should be restricted to light-absorbing refractory carbonaceous matter of uncertain character and 2) the uncertainty be stated explicitly. We also propose a more precise definition for soot as a specific material, which we call ns-soot, where "ns" refers to carbon nanospheres. We define ns-soot as particles that consist of nanospheres, typically with diameters <100 nm, that possess distinct structures of concentrically wrapped, graphene-like layers of carbon and with grape-like (acinoform) morphologies.;

  14. Optical properties of cadmium implanted GaSb

    NASA Astrophysics Data System (ADS)

    Pandey, S. D.; Dubey, R. L.; Dubey, S. K.

    2013-06-01

    Single crystal, n-type GaSb (gallium antimonide) was implanted with 300 keV 112Cd (cadmium) ions for various ion fluences varying from 1 × 1013 to 1 × 1016 cm-2. Fourier Transform Infra-red studies revealed that the optical absorbance and defect density increased but optical band gap decreased with increase in ion fluence. Rapid thermal annealing of sample implanted with ion fluence 1 × 1013 cm-2 showed significant damage recovery.

  15. Ion-implanted drift field silicon solar cell

    Microsoft Academic Search

    H. Y. Lee; J. K. Kim; Y. S. Kim

    1977-01-01

    Development of a single-side drift-field silicon solar cell with the structure p(+)-p-n is discussed. The p-n junction is obtained by use of a gas discharge and heating implanter, which deposits dopant atoms onto the substrate by the processes of radiation-enhanced diffusion and, secondarily, hot implantation. The open-circuit voltage of the experimental solar cells is 0.44 V and the conversion efficiency

  16. Modeling and Simulation of Foreign Body Reactions to Neural Implants

    Microsoft Academic Search

    Jianzhong Su; Humberto Perez Gonzales; Liping Tang

    The fibrotic capsulations to neural implant within brains are found to substantially reduce the effectiveness of the devices.\\u000a While in vitro and in vivo experiments can single out each of the steps in foreign body reaction process leading to the formation\\u000a of fibrotic tissue surrounding implants, we need the predictive power to analyze the outcome of multiple interactive complex\\u000a kinetics

  17. Short Implants in Partially Edentuolous Maxillae and Mandibles: A 10 to 20 Years Retrospective Evaluation

    PubMed Central

    Lops, Diego; Bressan, Eriberto; Pisoni, Gianluca; Cea, Niccolò; Corazza, Boris; Romeo, Eugenio

    2012-01-01

    Purpose. Evaluation of the short implant (8?mm in height) long-term prognosis and of the implant site influence on the prognosis. Methods. A longitudinal study was carried out on 121 patients (57 males and 64 females) consecutively treated with 257 implants. 108 implants were short. Results. Four (3.6%) short implants supporting fixed partial prostheses failed. Similarly, three standard implants supporting fixed partial prostheses and one supporting single-crown prosthesis failed. Mean marginal bone loss (MBL) and probing depth (PD) of short and standard implants were statistically comparable (P > .05). The 20-year cumulative survival rates of short and standard implants were 92.3 and 95.9%, respectively. The cumulative success rates were 78.3 and 81.4%. The survival rates of short implants in posterior and anterior regions were comparable: 95 and 96.4%, respectively. The difference between survival rates was not significant (P > .05). Conclusions. The high reliability of short implants in supporting fixed prostheses was confirmed. Short and standard implants long-term prognoses were not significantly different. The prognosis of short implants in posterior regions was comparable to that of in anterior regions. Nevertheless, a larger sample is required to confirm this trend. PMID:22829823

  18. Broad beam ion source for ion implantation

    Microsoft Academic Search

    Feng Yucai; Tian Feng

    1990-01-01

    A broadbeam ion source for ion implantation has been developed. The features of this source include high current density, large beam spot area, and good beam current density uniformity. It can be equipped with a single or multiaperture ion extraction system and can be operated over energy and current ranges of 3–120 keV and 1–60 mA, respectively. Ion beam current

  19. Positron implantation in solids

    SciTech Connect

    Ghosh, V.J.; Lynn, K.G.; Welch, D.O.

    1993-12-31

    The Monte Carlo technique for modeling positron prior to annihilation and electron implantation in semi-infinite metals is described. Particle implantation is modelled as a multistep process, a series of collisions with the atoms of the host material. In elastic collisions with neutral atoms there is no transfer of energy. The particle loses energy by several different channels, excitation of the electron gas, ionization of the ion cores, or, at low energies, by phonon excitation. These competing scattering mechanisms have been incorporated into the Monte Carlo framework and several different models are being used. Brief descriptions of these Monte Carlo schemes, as well as an analytic model for positron implantation are included. Results of the Monte Carlo simulations are presented and compared with expermental data. Problems associated with modeling positron implantation are discuss and the need for more expermental data on energy-loss in different materials is stressed. Positron implantation in multilayers of different metals is briefly described and extensions of this work to include a study of multilayers and heterostructures is suggested.

  20. Mutations in the Myelin Protein Zero result in a spectrum of Charcot-Marie-Tooth phenotypes.

    PubMed

    Kocha?ski, A

    2004-05-01

    Initially the Myelin Protein Zero gene was shown to be mutated in the demyelinating form of Charcot-Marie-Tooth disease (CMT1). The vast majority of the mutations in the Myelin Protein Zero gene have been detected in the Charcot-Marie-Tooth (1B) disease, however, some of them were found in patients suffering from congenital hypomyelinating neuropathy and axonal type Charcot-Marie-Tooth disease. In this study, a Charcot-Marie-Tooth disease phenotype diversity associated with different mutations in the MPZ gene, is described. PMID:15298082