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1

Single-Tooth Implants  

MedlinePLUS

... a crown. The final crown in place The restoration (the part that looks like a tooth) is ... has had advanced training in the placement and restoration of implants. Your dentist will do a comprehensive ...

2

Incidence of Endodontic Implantitis and Implant Endodontitis Occurring with Single-tooth Implants: A Retrospective Study  

Microsoft Academic Search

The purposes of this study were to determine success and survival rates for implants and teeth adjacent to implants and the incidence of endodontic implantitis (E-I) (endodontic involvement in adjacent teeth causing implant failure) and implant endodontitis (I-E) (implant placement causing endodontic failure). The data were from 233 single-tooth implants placed in 116 subjects by postgraduate periodontal students with recall

Bradley S. Laird; Michael S. Hermsen; Tom G. Gound; Fahd Al Salleeh; Matthew R. Byarlay; Merlyn Vogt; David B. Marx

2008-01-01

3

Single-tooth implant rehabilitation: a retrospective study of 67 implants.  

PubMed

The use of osseointegrated implants is an accepted procedure for the treatment of total and partial edentulism and offers good predictability of long-term success. For the last several years, this procedure has also been used for single-tooth replacement following loss of teeth for traumatic, periodontal, and carious lesions. This paper reports the clinical experience of 47 patients treated for a single-tooth replacement. Sixty-seven screw-type standard, self-tapping implants and mini-implants were placed. The results were similar to those for complete and partial osseointegrated prostheses. The total implant survival rate was 94.4%. Two implants were lost as a result of suppuration caused by membrane exposure, while another was lost after loading. The results suggest that single-tooth replacement using osseointegrated implants provides predictable success. PMID:7748446

Cordioli, G; Castagna, S; Consolati, E

1994-01-01

4

Prosthetic replacement of congenitally missing teeth using single-tooth osseointegrated implants: a case report.  

PubMed

This article presents the use of single-tooth implants in the rehabilitation of a 17-year-old patient with congenitally missing teeth. Treatment options are discussed, and advantages of the use of osseointegrated fixtures in the rehabilitation of partial anodontia patients are presented. A dental team approach is advocated. PMID:2097057

Lanzi, G L; Seran, C C; Cohen, S R

1990-09-01

5

Surgical Tooth Implants, Combat and Field.  

National Technical Information Service (NTIS)

Long term implant studies of alumina tooth roots are being performed in both humans and baboons. The implants designed for this project are a single root rectangular design with serrations arranged for maximal stress distribution of occlusal loads. THe im...

C. R. Hassler R. M. Downes L. G. McCoy

1981-01-01

6

Surgical Tooth Implants, Combat and Field.  

National Technical Information Service (NTIS)

Long term implant studies of alumina tooth roots are being performed in both humans and baboons. The implants designed for this project are single root elliptical and rectangular designs with serrations arranged for maximal stress distribution of occlusal...

C. R. Hassler R. M. Downes G. L. Messing O. E. Russell

1979-01-01

7

Surgical Tooth Implants, Combat and Field.  

National Technical Information Service (NTIS)

Long term implant studies of alumina tooth roots are being performed on both humans and baboons. The implants designed for this project are a single root rectangular design with serrations arranged for maximal stress distribution of occlusal loads. The im...

C. R. Hassler L. G. McCoy N. E. Arlin

1983-01-01

8

Surgical Tooth Implants, Combat and Field.  

National Technical Information Service (NTIS)

Long term implant studies of alumina tooth roots are being performed in both humans and baboons. The implants designed for this project are a single root rectangular design with serrations arranged for maximal stress distribution of occlusal loads. The im...

C. R. Hassler R. M. Downes L. G. McCoy

1982-01-01

9

Single tooth replacement utilizing implants in the esthetic zone: a case report.  

PubMed

Replacing a single tooth with an implant has become a common dental procedure; however, careful evaluation is necessary before placing one in the esthetic zone. Thorough diagnosis and planning - including the use of transposed diagnostic casts and cone beam computed tomography scans - can help dentists predict the final esthetic result prior to treatment, and help inform the patient of the potential result prior to performing any irreversible therapy. In the present case, the primary concern was the presurgical location of the facial free gingival margin (FGM) of the implant-supported crown, in relation to the adjacent teeth. Steps taken to correct the position of the facial FGM prior to implant placement led to a successful esthetic result. PMID:23823341

Egbert, Nicholas; Ahuja, Swati; Brandt, Robert; Jain, Vinay; Wicks, Russell

2013-07-01

10

Are predoctoral students able to provide single tooth implant restorations in the maxillary esthetic zone?  

PubMed

The objective of this study was to assess the ability of the University of Illinois at Chicago College of Dentistry (UIC-COD) predoctoral students to provide single tooth implant (STI) prostheses in the maxillary esthetic zone. The patient's esthetic satisfaction and the correlation between prosthodontists' and patients' perspectives were examined. Twenty-seven patients were recruited for recall examinations at the UIC-COD predoctoral implant program and underwent clinical and radiographic examination with clinical photographs of the implant sites. The patients completed a semantic differential scale questionnaire. The collected information was formulated into a PowerPoint presentation for two Diplomate of the American Board of Prosthodontists to use the Pink/White Esthetic Score (PES/WES) to evaluate the esthetic outcome. Descriptive analyses, Cohen kappa test, and Spearman rank correlation coefficient test were performed. The average PES/WES were above 6.0 (out of 10). The median for the patient satisfaction and esthetic outcome questionnaires were 10 and 9, respectively, on a scale with 10=highest. There was a medium and positive correlation between prosthodontists' and patients' perspectives in esthetic outcome. This study found that, with strict guidance and proper selection criteria, predoctoral students were able to provide esthetically acceptable STI prostheses in the maxillary esthetic zone and patients were satisfied with the treatment provided. PMID:24789838

Taylor, Emily J; Yuan, Judy Chia-Chun; Lee, Damian J; Harlow, Rand; Afshari, Fatemeh S; Knoernschild, Kent L; Campbell, Stephen D; Sukotjo, Cortino

2014-05-01

11

Treatment of a Class II Division 2 malocclusion with space reopening for a single-tooth implant  

Microsoft Academic Search

This case report describes the treatment of an adolescent girl with a skeletal Class II Division 2 malocclusion and impinging overbite. One of 2 previously extracted premolars had to be replaced by a single-tooth implant after adequate space reopening. An optimal overbite-overjet relationship was achieved through significant intrusion and proclination of maxillary and mandibular incisors. A horizontally impacted mandibular second

Roy Sabri

2001-01-01

12

Evaluation of single-tooth replacement by an immediate implant covered with connective tissue graft as a biologic barrier  

PubMed Central

Background and Objectives: The aim of the present study was to evaluate the survival rate of Screw-Vent® immediate implants augmented with sub epithelial connective tissue graft for single-tooth replacement for 1 year. Materials and Methods: Ten patients (five men and five women), with the mean age of 25.3 years, were consecutively treated on the out-patient basis by the placement of Screw-Vent® dental implants in to the fresh extraction sockets in association of augmentation with sub epithelial connective tissue graft harvested from the palate, supporting single crowns. The clinical and radiographic parameters were recorded to evaluate the peri-implant soft tissue health and marginal bone loss, respectively, for each patient at baseline and at every 3 months interval for 1 year. Results: The 1 year cumulative survival rate of Screw-Vent® dental implants was 100% for all 10 patients. Statistical analysis demonstrated highly significant values indicating an improvement in peri-implant soft tissue parameters in terms of peri-implant aesthetic parameters, which estimated the keratinized mucosa width. Statistically, non-significant marginal bone loss or gain indicated stable condition in hard tissue parameters. Interpretation and Conclusion: Single-tooth replacement by Screw-Vent® dental implants in to a fresh extraction socket, in association with guided bone regeneration using autologous connective tissue graft is a predictable treatment as demonstrated by the 100% implant survival rates and appreciable increase in the width of the keratinized mucosa at 1 year follow up.

Jyothi, S. G.; Triveni, M. G.; Mehta, D. S.; Nandakumar, K.

2013-01-01

13

Immediate loading of two single tooth implants in the maxilla: preliminary results after one year.  

PubMed

This clinical report describes the traumatic avulsion of the left maxillary central and lateral incisors with minimal tissue trauma, followed by placement of provisional restorations of two root-form implants in a 14-year old female patient. Ten days following the avulsion, implant therapy was performed with Summers osteotomes and flapless technique using a root-form 3i osseotite NT. Angulated abutments and acrylic provisional crowns were placed. No occlusal contact was detected. An impression was made 30 days after implant insertion and ceramic restorations were placed 3 months later. No significant soft tissue contraction was observed during the provisional period. The patient exhibited no clinical or radiologic complications for 8 months after loading. In carefully selected under-aged patients implant therapy and immediate loading in the anterior maxilla for traumatic tooth avulsion may prove to be valuable to avoid soft tissue contraction, alveolar bone resorption, and positive esthetic/psychological response. PMID:16127484

Nuzzolese, Emilio

2005-08-15

14

Fracture resistance of single-tooth implant-supported zirconia-based indirect composite-layered molar restorations.  

PubMed

OBJECTIVES: This study evaluated the fracture resistance of single-tooth implant-supported zirconia-based indirect composite-layered molar restorations. MATERIAL AND METHODS: Forty-four titanium abutments (GingiHue Post) were placed on dental implants (Osseotite Implant). Standardized single-tooth cement-retained implant-supported mandibular molar restorations were fabricated for each of four test groups (n = 11) as follows: porcelain-fused-to-metal crowns (PFM), zirconia-based all-ceramic crowns (ZAC), zirconia-based indirect composite-layered crowns primed with Estenia Opaque Primer for zirconia frameworks (ZIC-E), and zirconia-based indirect composite-layered crowns (ZIC). The crowns were luted with a glass-ionomer cement (Ketac Cem Easymix). Fracture resistance (N) was determined by force application of a perpendicular load to the crowns with a universal testing machine. One-way analysis of variance (ANOVA) and the Tukey's HSD test were used to assess differences in fracture resistance values (? = 0.05). RESULTS: Mean fracture resistances (SD) were 3.09 (0.22) kN, 3.11 (0.34) kN, 2.84 (0.21) kN, and 2.50 (0.36) kN for the PFM, ZAC, ZIC-E, and ZIC groups, respectively. Fracture resistance in the ZIC specimens was significantly lower (P < 0.044) than that in the other groups, which did not significantly differ. CONCLUSIONS: The fracture resistance of single-tooth implant-supported zirconia-based indirect composite-layered molar crowns primed with Estenia Opaque Primer for zirconia frameworks (ZIC-E) is comparable to that of porcelain-fused-to-metal (PFM) and zirconia-based all-ceramic (ZAC) restorations. Application of Estenia Opaque Primer to zirconia ceramic framework provides superior fracture resistance in implant-supported zirconia-based indirect composite-layered molar crowns. PMID:23730807

Taguchi, Kohei; Komine, Futoshi; Fushiki, Ryosuke; Blatz, Markus B; Kamio, Shingo; Matsumura, Hideo

2013-06-01

15

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

Microsoft Academic Search

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

T. K. Pal; S. Pal

1995-01-01

16

Active Tactile Sensibility of Single-Tooth Implants versus Natural Dentition: A Split-Mouth Double-Blind Randomized Clinical Trial.  

PubMed

BACKGROUND: Unlike passive sensitivity of implants/teeth that is assessed more, only three controversial studies have compared active tactile sensibility (ATS) of implants and teeth. PURPOSE: We aimed to explore the difference between the ATS of teeth and single-tooth implants. METHODS: The ATS of single-tooth implants and contralateral teeth was measured in 25 patients after they bit on gold and placebo foils 0- to 70-?m thick, each for five times, in a random order blinded to patients and assessor, carried out at two sessions. Based on the experimental range of 0??m (mock trials) to 70??m, the sigmoid shape of psychometric curve was estimated to locate the 50% values as the ATS thresholds for each tooth or implant. ATS Data were analyzed using paired and unpaired t-tests and multiple linear regression (??=?0.05, ????0.1). Also, equivalence testing approach was used to assess semi-objectively the clinical significance. RESULTS: Average ATS values for teeth and implants were 21.4?±?6.55??m and 30.0?±?7.55??m, respectively (p?=?.0001 [paired t-test]). None of the geometric characteristics of implants nor duration of implant in function were correlated with the ATS (p?>?.4 [regression]). Age was positively associated with the ATS of both implants and teeth (p???.019 [regression]). Tooth ATS (but not implant ATS) was significantly higher in males compared with females (p?=?.050 [unpaired t-test]), which contributed to a generalizable tooth-implant difference higher than 8-?m clinical equivalence margin in females. The ATS was not significantly different between arches or between anterior/posterior regions (p?>?.6). CONCLUSION: There was a slight but statistically significant difference between implant and tooth tactile sensitivities. PMID:23490397

Kazemi, Mahmoud; Geramipanah, Farideh; Negahdari, Ramin; Rakhshan, Vahid

2013-03-14

17

Implants for single-tooth replacement. A clinical and experimental study on the Brånemark CeraOne System.  

PubMed

The general aim of the thesis was to study single-tooth replacements with implants using a recently developed prosthodontic concept, CeraOne. More specifically, the aims were to present prosthodontic procedures and early clinical experiences of CeraOne, and to study the following: the acceptance and the rejection of referred patients, the mechanical strength of the complete implant post and of superstructures on the CeraOne abutment, the treatment outcome from an on-going prospective clinical investigation, the effect of guided tissue regeneration when using e-PTFE membranes in narrow alveolar ridges, and finally, the outcome from treatments by general practitioners (GPs) who had performed the complete care of the single-tooth patient. The acceptance and the rejection of patients were studied on 184 patients, and the conclusions were based on data from referral, case history, clinical examination, and therapy planning. External trauma, root fractures, and congenitally missing teeth were the main reasons for lost or missing teeth in referred patients, while anatomical limitations were the most frequent reasons for the rejections. The mechanical strength was determined after testing in an Instron universal testing machine. The abutment screw was shown to be the weakest link, while a satisfactory safety margin against fractures was observed for the metal-ceramic and the all-ceramic crowns. It was also shown that the all-ceramic ¿ crown could resist bending moments up to a level that was more than three times as high as the one at which the porcelain crown fractured. In the clinical prospective study, the results from treatments of 57 patients (65 implants) were reported after two years and from 34 patients (37 implants) after three years. Favourable survival rates were shown for the implants (97.3% at 3-4 years) and, as a mean, only a small bone loss around the implants and the adjacent teeth was observed. The conical implants, however, showed a higher degree of bone los in comparison to the other implants. The CeraOne prosthodontic concept was simple to sue because of prefabricated components, and favourable aesthetic and clinical short-term results were achieved. Problems of screw loosening and fistulas were avoided and the cementation of the crown and the subgingival placement of the abutment shoulder did not cause any soft tissue recession. Fifteen patients (20 implants) with a suspected need of guided tissue regeneration were selected for the study using e-PTFE membranes. After treatment and at the second stage surgery, it was shown that most of the primarily exposed implant surfaces at this time were covered by a newly formed tissue with signs of osteoid activity.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7644974

Andersson, B

1995-01-01

18

Surgical Tooth Implants, Combat and Field.  

National Technical Information Service (NTIS)

Studies have been conducted concerning the development of improved, high-density, high-strength grooved alumina tooth root structures of the nonbifurcated design for monkey and human implant studies. Biomechanical stabilization of the implants in a tooth ...

C. R. Hassler, T. D. Driskell, L. G. McCoy, D. E. Niesz

1974-01-01

19

Comparative study of antirotational single tooth abutments.  

PubMed

Identifying the functional and mechanical limitations of single tooth implant systems is essential for the long-term success of the restoration. Three designs with different prosthetic connections were evaluated with their corresponding single tooth abutments for structural integrity and cyclic fatigue. The internal implant octagon was the weakest connection under off-axis impact loading and lateral loading, and the external hexagon implant was rendered unrestorable under lateral loading. Overall, the internal hexagon design was found to provide the highest degree of single tooth stability. This was attributed to the increased material strength of the titanium alloy implant in comparison to the softer CP titanium implant, and to the abutment's longer, 1-degree tapered mating hexagon. PMID:7699597

Balfour, A; O'Brien, G R

1995-01-01

20

Evaluation of soft tissues around single tooth implants in the anterior maxilla restored with cemented and screw-retained crowns.  

PubMed

Implant-supported restorations can be attached as screw-retained or cemented prostheses. In both situations, the characteristics of the soft tissues around the implants are crucial for oral rehabilitation and patient satisfaction. Therefore, this study uses the Pink Esthetic Score (PES), which allows evaluation of gingival esthetics around implants, to evaluate the soft tissues around implants in the anterior maxilla rehabilitated with cemented prostheses (CP) and screw-retained prostheses (SP). Forty implants placed in the anterior maxilla were evaluated, and these had been rehabilitated with prosthetic crowns for a minimum of 1 year. Periodontal examination was performed to evaluate probing depth (PD) and bleeding on probing (BOP) of the implant and the corresponding natural tooth. The total mean (±SD) PES for SP was 10.73 (±1.98) and 10.41 (±2.67) for CP, which was not statistically significant (P ? .05). Periodontal examination revealed that CP and SP showed no difference for BOP (P ? .05). Differences were only detected in PD when comparing the reference teeth of both groups to CP and SP (P ? .05). The present study demonstrates that the PES proved to be an efficient index to assess peri-implant tissues, and that the type of crown retention does not influence the health and quality of the soft tissues around implants. PMID:21905890

Cutrim, Emerson Souza; Peruzzo, Daiane Cristina; Benatti, Bruno

2012-12-01

21

Influence of Laser-Lok surface on immediate functional loading of implants in single-tooth replacement: a 2-year prospective clinical study.  

PubMed

The purpose of this study was to evaluate the influence of a Laser-Lok microtexturing surface on clinical attachment level and crestal bone remodeling around immediately functionally loaded implants in single-tooth replacement. Seventy-seven patients were included in a prospective, randomized study and divided into two groups. Group 1 (control) consisted of non-Laser-Lok type implants (n = 39), while in group 2 (test), Laser-Lok type implants were used (n = 39). Crestal bone loss (CBL) and clinical parameters including clinical attachment level (CAL), Plaque Index (PI), and bleeding on probing were recorded at baseline examinations and at 6, 12, and 24 months after loading with the final restoration. One implant was lost in the control group and one in the test group, giving a total survival rate of 96.1% after 2 years. PI and BOP outcomes were similar for both implant types without statistical differences. A mean CAL loss of 1.10 ± 0.51 mm was observed during the first 2 years in group 1, while the mean CAL loss observed in group 2 was 0.56 ± 0.33 mm. Radiographically, group 1 implants showed a mean crestal bone loss of 1.07 ± 0.30 mm compared with 0.49 ± 0.34 mm for group 2. The type of implant did not influence the survival rate, whereas Laser-Lok implants resulted in greater CAL and in shallower radiographic peri-implant CBL than non-Laser-Lok implants. PMID:24396842

Farronato, Davide; Mangano, Francesco; Briguglio, Francesco; Iorio-Siciliano, Vincenzo; Riccitiello, Francesco; Guarnieri, Renzo

2014-01-01

22

Pre-fabricated zirconium dioxide implant abutments for single-tooth replacement in the posterior region: success and failure after 3 years of function.  

PubMed

Abstract Objective. Zirconia implant abutments have gained a much broader clinical use over the past few years. The aim of the present study was to assess the clinical performance of a pre-fabricated zirconium dioxide implant abutment for single-tooth replacement in the posterior region. Materials and methods. Forty implants of the XiVE® S plus screw type (DENTSPLY Friadent, Mannheim, Germany) were inserted in the posterior region of 24 patients and provided with zirconium dioxide abutments (FRIADENT® CERCON® Abutment, DENTSPLY Friadent). The following parameters were used to document the state of soft tissue: modified plaque index, modified sulcus bleeding index and pocket depth. Mesial and distal bone levels were determined on radiographs during the prosthetic treatment and at the 36-month recall. Results. Thirty-seven implants could be followed up after 36 months in function. One patient wearing two abutments was lost to follow-up. One abutment exhibited a rotational misfit after 2 years in function. A further abutment showed the same failure at the 36-months recall appointment. In the remaining 36 implants the soft and hard tissue parameters were indicative of a low inflammatory status. Compared to the baseline situation, a partly significant bone apposition could be observed. Chipping of parts of the veneering ceramic was registered in 22% of the remaining implant restorations. Conclusions. The use of zirconia abutments in this study lead to mainly healthy peri-implant hard and soft tissue conditions but, considering the observed failures after 3 years in function, clinical long-term results should be awaited before recommending full zirconia implant abutments in a posterior indication. PMID:24304290

Nothdurft, Frank P; Nonhoff, Joerg; Pospiech, Peter R

2014-07-01

23

Use of titanium mesh in implant site development for restorative-driven implant placement: case report. Part 2: surgical protocol for single-tooth esthetic zone sites.  

PubMed

There are many techniques in the dental implant literature to augment bone for implant site development. The use of rigid titanium mesh was first described by Boyne in the mid-1980s to maintain regenerative space and to aid in unimpeded bone healing. Ti-mesh was used in this case report to demonstrate the predictability of this technique in creating bone augmentation in both a lateral and vertical direction prior to the placement of a single implant in site No. 5. The article describes the surgical steps for the use of ti-mesh in a single esthetic zone site with a 3-year follow-up. PMID:24841037

Levine, Robert A; Manji, Aleem; Faucher, Joanie; Fava, Philip

2014-05-01

24

Use of titanium mesh in implant site development for restorative-driven implant placement: case report. Part 1: restorative protocol for single-tooth esthetic zone sites.  

PubMed

Predictably augmenting alveolar bone is a significant challenge in implant site development. A restorative-driven approach to implant placement aids in achieving esthetic harmony in the final restoration. This case report demonstrates techniques for treating patients with significant bony defects using a titanium mesh scaffold along with prosthetic steps in molding and conditioning soft tissues with the provisional restoration and the fabrication of a custom impression coping. This case is part of a larger consecutive case series of 77 titanium mesh units in 62 patients treated in a private periodontal practice setting and restored in private restorative practices, which will be published subsequently. In this titanium mesh case series, 14 other cases (a total of 15) were treated in a similar fashion as described in this case report in the category of "single implant placement in the maxillary anterior region." This case illustrates the primary advantages of the use of titanium mesh in such clinical situations. PMID:24773252

Levine, Robert A; Manji, Aleem; Faucher, Joanie; Present, Steven

2014-04-01

25

A single-tooth, two-piece zirconia implant located in the anterior maxilla: a clinical report.  

PubMed

It can be difficult to achieve a natural appearance in the anterior region with implant-supported restorations because metal components may show through the soft tissue. Zirconia implants, therefore, should be considered as an alternative treatment for improved esthetics. The goal of this clinical report was to evaluate a new 2-piece zirconia implant system for the maxillary anterior region. A 2-piece zirconia dental implant was placed in the maxillary left lateral incisor position and left in place for 6 months to osseointegrate. Panoramic and periapical radiographs were examined for bone-implant osseointegration. The plaque control record (PCR), bleeding on probing (BOP), and probing depth (PD) were measured after the cementation of the definitive restoration and a 6-month follow-up period. The PCR, BOP, and PD values were compared and the marginal bone level was also evaluated by making standardized periapical radiographs. The results showed that over the 6-month follow-up period, the marginal area was healthy and presented no bleeding on probing, no plaque accumulation, and no change in periimplant marginal bone level. PMID:23395330

Ayd?n, Cemal; Y?lmaz, Handan; Banko?lu, Merve

2013-02-01

26

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

PubMed Central

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

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

2014-01-01

27

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

PubMed

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

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

2014-01-01

28

All-ceramic single-tooth implant reconstructions using modified zirconia abutments: a prospective randomized controlled clinical trial of the effect of pink veneering ceramic on the esthetic outcomes.  

PubMed

The aim of this study was to test whether veneering of the submucosal part of zirconia abutments using pink veneering ceramic positively influences the color of the peri-implant mucosa. Single-tooth implants were restored with either white zirconia abutments (control group) or pink-veneered zirconia abutments and all-ceramic crowns. Esthetic outcome measurements included a spectrophotometric evaluation of the peri-implant mucosal color. Test and control groups induced a visible discoloration of the peri-implant mucosa after the insertion of the abutments and following cementation of the crowns compared to natural teeth. The calculated color differences were above the clinically visible threshold value and were more favorable for the control group, although not statistically significant. It is concluded that veneering of zirconia abutments with pink veneering ceramic failed to positively influence the esthetic outcome, mostly due to a decrease of the brightness compared with the control group. PMID:24396838

Büchi, Dominik L E; Sailer, Irena; Fehmer, Vincent; Hämmerle, Christoph H F; Thoma, Daniel S

2014-01-01

29

Prognosis and evaluation of tooth damage caused by implant fixtures.  

PubMed

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

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

2013-06-01

30

Evidence-Based Decision Making: Replacement of the Single Missing Tooth  

Microsoft Academic Search

Single-tooth replacement may be effected through use of a resin-bonded fixed partial denture (RBB), a conventional fixed partial denture (FPD), a removable prosthesis, or a single implant-supported crown (SIC). The use of a removable prosthesis is excluded from consideration because the final treatment result of a removable pros- thesis for replacement of a single missing tooth is considered a compromise

Paul A. Fugazzotto

2009-01-01

31

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

Microsoft Academic Search

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

Frank Philipp Nothdurft; Sabine Merker; Peter Reinhard Pospiech

2011-01-01

32

Nanofibers implant functionalized by neural growth factor as a strategy to innervate a bioengineered tooth.  

PubMed

Current strategies for jaw reconstruction require multiple procedures, to repair the bone defect, to offer sufficient support, and to place the tooth implant. The entire procedure can be painful and time-consuming, and the desired functional repair can be achieved only when both steps are successful. The ability to engineer combined tooth and bone constructs, which would grow in a coordinated fashion with the surrounding tissues, could potentially improve the clinical outcomes and also reduce patient suffering. A unique nanofibrous and active implant for bone-tooth unit regeneration and also the innervation of this bioengineered tooth are demonstrated. A nanofibrous polycaprolactone membrane is functionalized with neural growth factor, along with dental germ, and tooth innervation follows. Such innervation allows complete functionality and tissue homeostasis of the tooth, such as dentinal sensitivity, odontoblast function, masticatory forces, and blood flow. PMID:24124118

Eap, Sandy; Bécavin, Thibault; Keller, Laetitia; Kökten, Tunay; Fioretti, Florence; Weickert, Jean-Luc; Deveaux, Etienne; Benkirane-Jessel, Nadia; Kuchler-Bopp, Sabine

2014-03-01

33

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

PubMed

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

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

2011-02-01

34

Management of the single discoloured tooth. Part 2: Restorative options.  

PubMed

This is the second article of a two part series covering the aetiology, prevention and broad range of management options for the single discoloured tooth. The article covers situations where masking and simulation techniques with direct composite are required. Direct composite, indirect composite and ceramic veneers are then considered, as well as full coverage crowns. The option of extraction of the affected tooth and its prosthodontic replacement will also be considered. Clinical cases are used to illustrate various scenarios. Clinical Relevance: The single discoloured tooth is a commonly encountered clinical problem in general dental practice. A wide variety of management options exist and it is recommended that general dental practitioners consider adopting minimally invasive techniques in the first instance before moving on to more invasive therapies. PMID:24839707

Barber, Andrew J; King, Paul A

2014-04-01

35

Influence of Tooth Design on Implant Acceptability in Animals.  

National Technical Information Service (NTIS)

A study of the effect of root design on dental implant acceptability in baboons is being continued. In Phase II, using four PMMA (poly (methyl methacrylate)) implant root design combinations--smooth, grooved, perforated nonporous, and perforated porous--a...

L. B. Shulman P. A. Schnitman L. Gettleman M. Hodosh G. Shklar

1975-01-01

36

Determining the effect of implant surgery on blood oxygen saturation of the adjacent tooth  

PubMed Central

Background: Implant surgery requires local anesthesia and drilling. This surgery may affect the blood circulation of the adjacent teeth. In this study, we evaluated the blood oxygen saturation of the healthy adjacent tooth with a pulse oximeter, during implant surgery. Materials and Methods: In this clinical trial study, 15 healthy adult patients, who were candidates for anterior implant surgery and had healthy anterior adjacent teeth, were selected. Blood oxygen saturation of the adjacent tooth and index finger was measured with a pulse oximeter, before and after local anesthetic injection, and also immediately and one hour after completion of surgery. The collected data were analyzed with a Paired Samples Test and Spearman's Correlation Coefficient. (the significance level was at alpha P < 0.05). Results: The mean value of peripheral finger blood Spo2 before local anesthetic injection was 98.2% and remained stable during surgery. In the adjacent tooth, the mean values of the pulpal Spo2, before and after local anesthesia, were 87.73 and 79.27%, respectively; immediately after surgery it was 86.13% and one hour after surgery was 86.4%. The decrease in the value of pulpal Spo2 after local anesthesia compared to before the injection was significant. Also there was an inverse relationship between the numbers of utilized local anesthetic cartridges and the value of pulpal Spo2 after local anesthesia. Conclusion: After giving local anesthesia, the mean value of Spo2 in the adjacent tooth, because of the vasoconstructive effect of epinephrine, was decreased to about 8%. According to this study, the effect of the local anesthetic drug, containing epinephrine, on the blood circulation in the adjacent tooth was significantly more than the trauma from the implant surgery. We wonder if this temporary decrease in blood flow in the adjacent toot is clinically important or not. To answer this question more studies are required.

Kaviani, Nasser; Shahaboyi, Mohammad; Khabazian, Arezoo

2012-01-01

37

The level of buccal gingival margin around single and two adjacent implant restorations: a preliminary result  

PubMed Central

STATEMENT OF PROBLEM Little information is available about the buccal gingival level of multiple implant restorations. PURPOSE This study was aimed to evaluate the relationship between width and height of buccal soft tissue around single and 2 adjacent implant restorations. MATERIAL AND METHODS Four implant restoration groups (first and second molars, single second molars, posterior single restorations between teeth, and anterior single restorations between teeth) were randomly chosen from one dental institute. Each group comprised of 6 patients. After 6 months of function, silicone impressions were taken and stone models were fabricated for each restoration group. The stone models were cut in bucco-lingual direction at the most apical point of buccal gingival margin. The height and width of buccal supra-implant soft tissue were measured. One way ANOVA and Tukey HSD post hoc tests were performed to analyze the data obtained (P < .05). RESULTS The most unfavorable width-height ratio was noted for the group, which was comprised of the second molar in the multiple adjacent (first and second molar) implant-supported restorations. The group also resulted in the shorter height of buccal supra-implant mucosa rather than that of anterior single implant restorations between natural teeth. CONCLUSION To achieve a favorable level of buccal gingival margin, greater thickness of buccal supra-implant mucosa is required for the implant restorations without a neighboring natural tooth compared to the implant restorations next to a natural tooth.

Kim, Young-Bum; Shim, June-Sung; Han, Chong-Hyun

2009-01-01

38

Tooth morphology, implantation and replacement system of Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae).  

PubMed

The oropharyngeal cavity of Hoplias malabaricus, an ichthyophagous freshwater fish, is anatomically adapted to predation. Macroscopic and microscopic analyses were conducted in order to study the morphology and system of implantation and replacement of teeth. The results showed that this teleost has conical and caniniform teeth, with an orthodentin crown covered by an enameloid cap and a vascularised orthodentin in the root. With regard to the implantation system, there is a junction between the tooth and the bone tissue, as a typical physiological dental ankylosis. The teeth are replaced by a resorption process of multinucleated giant cells that actively eliminate the dentin and bone tissue. PMID:24789394

Hassunuma, Rm; Stipp, Acm; Heubel, Mtcd; Cestari, Tm; Ceolin, Ds; Nakamura, Rsb; Rosseti, Pho; Assis, Gf

2013-11-01

39

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

PubMed

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

Pedersen, K N

1979-01-01

40

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

PubMed Central

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.

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

2011-01-01

41

Immediate, non-submerged, root-analogue zirconia implants placed into single-rooted extraction sockets: 2-year follow-up of a clinical study  

Microsoft Academic Search

This study evaluated non-submerged, root-analogue zirconia implants with two different surfaces for immediate single-rooted tooth replacement in 18 patients. After tooth extraction the root was laser scanned and one-piece root analogue zirconia dental implants with one of two different surfaces were manufactured. In group A (n=6) the implant surface was roughened by sandblasting only, in group B (n=12) additional macroretentions

W. Pirker; A. Kocher

2009-01-01

42

Immediate provisionalization of single extraction-site implants in the esthetic zone: a clinical evaluation.  

PubMed

Forty patients received a total of 43 implants placed in fresh extraction sites in the anterior maxilla. Within 1 week, a provisional crown was placed without occlusal contact. After 1 year, the implant survival rate, marginal bone resorption, and papillae preservation were assessed. The overall survival rate was 95.3%. The 1-year marginal bone loss was not statistically significant when compared to the marginal bone level at implant placement. In 78% of patients, the papilla was completely preserved. Single-tooth rehabilitation patients with buccal or circumferential defects can be predictably treated with a favorable esthetic outcome using the immediate provisionalization approach. PMID:20224830

Valentini, Pascal; Abensur, David; Albertini, Jacques F; Rocchesani, Marcel

2010-02-01

43

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

PubMed

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

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

2012-01-01

44

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

PubMed Central

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

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

2012-01-01

45

Management of the single discoloured tooth. Part 1: Aetiology, prevention and minimally invasive restorative options.  

PubMed

The single discoloured tooth is commonly encountered in general practice. This is the first of two articles covering the broad range of management options for the single discoloured tooth. This first part outlines the common causes of discoloration and possible methods of prevention. Minimally invasive techniques are covered. Clinical procedures are outlined and clinical cases used to demonstrate outcomes that can be achieved. Clinical Relevance: The single discoloured tooth is a commonly encountered clinical problem in general dental practice. A wide variety of management options exist and any one in particular may be most appropriate given the clinical scenario. It is therefore essential that general dental practitioners are familiar with the range of options that exist, as well as their indications, and consider adopting minimally invasive techniques in the first instance before moving to more invasive therapies. PMID:24783878

Barber, Andrew; King, Paul

2014-03-01

46

Freestanding and tooth-implant connected prostheses in the treatment of partially edentulous patients. Part I: An up to 15-years clinical evaluation.  

PubMed

In 123 patients, 339 implants were connected to 313 teeth by means of fixed partial prostheses (test) and followed up for 1.5-15 years (mean: 6.5). In another ad random selected 123 patients, 329 implants were connected to each other by means of 123 freestanding fixed partial prostheses (control) and were followed up for 1.3-14.5 years (mean: 6.2). The aim of this study was to compare both treatment modalities with each other based on implant, tooth and prosthesis complications. The cumulative implant success, based on implant immobility and/or lack of implant fractures after loading, in the test and control groups amounted to 95% and 98.5%, respectively. Although in the test group 10 implants versus only 1 in the control group failed, a regression analysis of the survival data, based on the cox proportional hazards model, revealed no significant difference. In the test group periapical lesions (3.5%), tooth fracture (0.6%) and tooth extraction due to fatal decay or periodontitis (1%) were observed, besides tooth intrusion (3.4%) and crown cement failure (8%). Framework fracture occurred in 3 patients. In the control group, only 2 abutment screws fractured. The treatment of partial edentulism by means of oral implants was beneficial for our patients. Because of a clear tendency of more implant failures (mobility or fractures) and tooth complications in the tooth-implant connected prostheses, the freestanding solution is the primary option to be considered. To avoid intrusion of abutment teeth, the connection, if made, should be completely rigid. PMID:11359481

Naert, I E; Duyck, J A; Hosny, M M; Van Steenberghe, D

2001-06-01

47

Histologic assessment of alveolar bone remodeling around immediate implants placed in single and multiple contiguous extraction sites.  

PubMed

The aim of this study was to histologically assess alveolar bone remodeling around immediate implants placed in single and multiple contiguous extraction sites. Ten dogs were divided into three groups (with six sites per group) on the basis of premolar teeth extraction: group 1 = one tooth extracted, group 2 = two contiguous teeth extracted, and group 3 = more than two contiguous teeth extracted. Immediate implants were placed in each group. Histologic assessment of arches showed no evidence of vertical bone loss (VBL) around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .001). Buccal and lingual bone thicknesses and bone-to-implant contact (BIC) were higher around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .05). Buccal and lingual bone thicknesses, BIC, and VBL are compromised around implants in multiple contiguous extraction sites compared with those in a single extraction site. PMID:24804293

Al-Rasheed, Abdulaziz; Al-Shabeeb, Munirah Saleh; Babay, Nadir; Javed, Fawad; Al-Askar, Mansour; Wang, Hom-Lay; Al-Hezaimi, Khalid

2014-01-01

48

Congenitally Missing Maxillary Lateral Incisors: Functional and Periodontal Aspects in Patients Treated with Implants or Space Closure and Tooth Re-Contouring  

PubMed Central

To evaluate functional and periodontal aspects in patients with unilateral or bilateral congenitally missing maxillary lateral incisors, treated with either implants or space closure and tooth re-contouring. The sample consisted of 68 volunteers, divided into 3 groups: SCR - space closure and tooth re-contouring with composite resin (n = 26); SOI – implants placed in the area of agenesis (n = 20); and CG - control group (n = 22). A modified Helkimo questionnaire and the Research Diagnostic Criteria for Temporomandibular Disorders were used by a single, previously calibrated evaluator to assess signs and symptoms of temporomandibular joint disorder. The periodontal assessment involved the following aspects: plaque index, bleeding upon probing, pocket depth greater than 3 mm, gingival recession, abfraction, periodontal biotype and papilla index. The data were analyzed using Fisher's exact test and the nonparametric Mann-Whitney and Kruskal-Wallis tests (?=.05). No differences in periodontal status were found between treatments. None of the groups were associated with signs and symptoms of temporomandibular joint disorder. Both treatment alternatives for patients with congenitally missing maxillary lateral incisors were satisfactory and achieved functional and periodontal results similar to those of the control group.

Marchi, Luciana Manzotti De; Pini, Nubia Inocencya Pavesi; Hayacibara, Roberto Massayuki; Silva, Rafael Santos; Pascotto, Renata Correa

2012-01-01

49

3D finite element analysis of immediate loading of single wide versus double implants for replacing mandibular molar  

PubMed Central

Purpose: The purpose of this finite element study was to compare the stresses, strains, and displacements of double versus single implant in immediate loading for replacing mandibular molar. Materials and Methods: Two 3D FEM (finite element method) models were made to simulate implant designs. The first model used 5-mm-wide diameter implant to support a single molar crown. The second model used 3.75-3.75 double implant design. Anisotropic properties were assigned to bone model. Each model was analyzed with single force magnitude (100 N) in vertical axis. Results: This FEM study suggested that micromotion can be controlled better for double implants compared to single wide-diameter implants. The Von Mises stress for double implant showed 74.44% stress reduction compared to that of 5-mm implant. The Von Mises elastic strain was reduced by 61% for double implant compared to 5-mm implant. Conclusion: Within the limitations of the study, when the mesiodistal space for artificial tooth is more than 12.5 mm, under immediate loading, the double implant support should be considered.

Desai, Shrikar R.; Karthikeyan, I.; Gaddale, Reetika

2013-01-01

50

Single-tooth replacement with a chairside prefabricated fiber-reinforced resin composite bridge: a case study.  

PubMed

There are many fixed options for replacing a single anterior tooth, including implants; conventional full coverage; porcelain-fused-to-metal, all-ceramic, and fiber-reinforced composite designs; and minimal preparation designs that utilize lingual wing frameworks made from metal, ceramic, or fiber-reinforced composite. All of these approaches require at least two visits; however, it is possible to replace a missing anterior tooth in a single visit by using adhesive techniques with resin composite and fiber-reinforced resin composite materials. This approach has been developed and refined with a bridge created at chairside, using a prefabricated fiber-reinforced composite framework. This framework consists of a pontic substructure that is shaped to support a resin composite pontic, with one or two wings used to attach the pontic substructure to either the lingual or facial surfaces of the abutment teeth. This article describes a chairside technique for replacing a maxillary central incisor by using a prefabricated fiber-reinforced framework. PMID:15636277

Arteaga, Sarita; Meiers, Jonathan C

2004-01-01

51

Immediate loading of single post-extractive implants in the anterior maxilla: 12-month results from a multicenter clinical study.  

PubMed

The purpose of the study was to evaluate survival and peri-implant bone levels of single, immediately loaded post-extractive implants in the anterior maxilla 12 months after implant placement. Thirty-six consecutive patients from 3 study centers were included in the study. The concerned sites were upper premolars, canines, and incisors. For each patient the following data were recorded: reason for tooth extraction, bone quality, implant size, and final insertion torque. Implants were placed using a flapless technique and immediately loaded with a nonoccluding temporary restoration. Final restorations were provided 4 months later. Peri-implant bone resorption was evaluated radiographically after 6 and 12 months. The average final insertion torque was 70.55 Ncm. One implant inserted in D3 quality bone with a 35-Ncm seating torque was lost. All other implants had a final insertion torque ranging between 50 and 80 Ncm. The average peri-implant bone loss was 0.437 and 0.507 mm at 6 and 12 months, respectively. All the sites maintained excellent papillae and peri-implant soft-tissue conditions. The resulting 1-year success rate was 97.2%. Immediate nonfunctional loading of single post-extractive implants in the anterior maxilla is a predictable treatment. And it seems that achieving high insertion torques by placing self-tapping/self-condensing implants in an underprepared osteotomy is favorable. PMID:21905885

Grandi, Tommaso; Garuti, Giovanna; Samarani, Rawad; Guazzi, Paolo; Forabosco, Andrea

2012-09-01

52

Atraumatic tooth extraction and immediate implant placement with Piezosurgery: evaluation of 40 sites after at least 1 year of loading.  

PubMed

This paper presents ultrasonic surgery (ie, Piezosurgery) as a new, relevant, and predictable method for performing atraumatic tooth extraction and subsequent implant site preparation. Forty noninfected teeth or roots were extracted in 23 patients and replaced immediately with implants. Extraction consisted of cutting the fibers of the periodontal ligament with vibrating tips of up to 10 mm in depth; the teeth or roots were mobilized afterward with an elevator. All teeth/roots were removed without fracture. Implant osteotomies were performed using conical tips of increasing diameters. During implant placement, notching of the apical third of the palatal wall or the interradicular bridge was performed without complication due to uncontrolled movements of the instrument. After a mean healing period of 2.4 months, all implants were osseointegrated and have been successfully loaded for at least 12 months. By implementing Piezosurgery, extraction can be atraumatic and implant placement can be predictable and undemanding compared to the use of burs, which can lead to instruments slipping during the procedure. PMID:20664837

Blus, Cornelio; Szmukler-Moncler, Serge

2010-08-01

53

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

PubMed

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

Fartash, B; Arvidson, K

1997-02-01

54

CAD/CAM-based implant abutments.  

PubMed

This article presents two novel options for lithium-disilicate restorations supported by single-tooth implants. By using a Ti-Base connector, hybrid abutments and hybrid abutment crowns can be fabricated for different implant systems. The latter option in particular is an interesting new process that yields economical and esthetic restorations supported by single-tooth implants. Further studies are urgently needed to validate the usefulness of this system. PMID:23930575

Kurbad, A; Kurbad, S

2013-01-01

55

Tracking of Tooth Contact Patterns in the Natural Dentition Using Miniaturized Implantable Telemetry Devices.  

National Technical Information Service (NTIS)

A study was conducted to investigate duration and frequency of tooth contacts in function and the effect of occlusal and adjustments on such contracts. Conclusions drawn from this study were the habitual occlusion was the position in which the mandible wa...

A. Haddad I. Glickman

1973-01-01

56

Step-by-step full mouth rehabilitation of a nasopharyngeal carcinoma patient with tooth and implant-supported prostheses: A clinical report  

PubMed Central

This clinical report presents a 46-year-old man diagnosed with nasopharyngeal carcinoma with the chief complaint of masticatory and speech deficiency because of radiation therapy. After a period of controlling post radiation caries, the patient was rehabilitated with tooth and implant supported metal ceramic restorations following surgical and endodontic intervention.

Alikhasi, Marzieh; Kazemi, Mahmood; Nokar, Saeed; Khojasteh, Arash; Sheikhzadeh, Sedigheh

2011-01-01

57

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

PubMed Central

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

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

2012-01-01

58

Dental Implants  

MedlinePLUS

... 11.14 Read More Find a Cosmetic Dentist Teeth Whitening Accredited and General Member Dental Patients ? Cosmetic Procedures ? Dental Implants Dental Implants The ... key benefit of dental implants over other tooth replacement systems is that an implant connects directly ...

59

Single crystal alumina for dental implants and bone screws.  

PubMed

When ground to a suitable form, flexural strength of single crystal alumina (Al2O3) decreases to as low as one third the strength of the intact crystal. This flexural strength decrease is, however, recovered by chemical etching at a high temperature to eliminate surface defects caused by grinding. By using this strength recovery treatment, various types of single crystal implants with fine structure were able to be designed. Four kinds of single crystal bone screws and single crystal dental implants of screw and anchor type were designed. Flexural strength and impact strength of the implants were measured. PMID:7349666

Kawahara, H; Hirabayashi, M; Shikita, T

1980-09-01

60

Soft tissue manipulation for single implant restorations  

Microsoft Academic Search

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

M. Corson; A. Alani

2011-01-01

61

Fabricating a nonrotational angulated abutment for a single-tooth prosthesis.  

PubMed

The fabrication of a custom waxed and cast nonrotational angulated abutment will be described. Most manufacturers of implant components fabricate angulated abutments for multiunit retrievable prostheses. However, they do not manufacture any components for a single unit that is screw retained. This article covers a step-by-step technique that was developed in an attempt to resolve this problem. PMID:20009602

Reid, Patrick E; Zinner, Ira D; Bhagat, Deepak

2009-12-01

62

Hard tooth tissue removal efficiency by single-mode low energy Er:YAG laser  

NASA Astrophysics Data System (ADS)

The ablation of dental hard tissue by the single-mode (TEM00) Er: YAG laser radiation was investigated. For the first time dependence of removal efficiency of enamel and dentin of human teeth on the single pulse energy TEM00 Er: YAG laser is represented. Attention is drawn to the correlation of laser energy and micro-craters form. The fact that the efficiency of human tooth enamel and dentin removal by TEM00 Er: YAG laser radiation are close to each other is deduced from experiments. Removal efficiency for enamel reaches the maximum value at pulse energy near 1 mJ and is equal 250+/-20 mm3/kJ. Removal efficiency for dentine also reaches the maximum at pulse energy near 1 mJ and is equal 265+/-20 mm3/kJ.

Belikov, A. V.; Skrypnik, A. V.; Shatilova, K. V.

2010-06-01

63

One-piece dowel-crown on single endosseous implants.  

PubMed

The unitized (one-piece) dowel-crown technique described in this article uses routine clinical and laboratory procedures, minimizes clinical appointments, and provides a simplified prosthetic restoration for a single dental implant. PMID:14560483

Ghorbani, Hamid; Pipko, Donald J

2003-01-01

64

Single and Multiple Microphone Noise Reduction Strategies in Cochlear Implants  

PubMed Central

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

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

2013-01-01

65

Optima XE Single Wafer High Energy Ion Implanter  

SciTech Connect

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.

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

66

The relationship between smile attractiveness and esthetic parameters of patients with lateral agenesis treated with tooth recontouring or implants  

PubMed Central

Background The purpose of this study was to associate smile esthetic judgment with dentofacial attributes of patients with unilateral and bilateral agenesis of maxillary lateral incisors treated with recontouring of canines or implants and patients with no agenesis (control). Material and methods Forty-six participants were divided into two groups: those treated with recontouring (N = 26) and those treated with implants (N = 20). The participants in the control group (N = 22) were selected among dentistry students at the State University of Maringá, Brazil. Photographs of posed smiles (17 cm × 10 cm) were evaluated with a 100-mm Visual Analog Scale. Smile attractiveness was judged by two groups: laypersons and dentists (N = 20 in each group). Judgment was classified into Unpleasant and Pleasant. Measurements of 11 smile attributes were done with ImageTool Version 3.0. These measurements were correlated with the type of judgment using the Pearson correlation coefficient. Results The two groups of evaluators showed no rating difference (analysis of variance, P = 0.64), thus they were placed into a single group. No significant correlation was found between esthetic judgment and six smile attributes (incisor exposure, interlabial gap, width 3 to 3, smile index, right buccal corridor, and buccal corridor ratio). The control group showed more correlations with the unpleasant judgment type than the other groups. Conclusion Some correlations between smile attributes and esthetic judgment were found, but other features of smiles not evaluated in this study may interfere in smile attractiveness.

De-Marchi, Luciana Manzotti; Pini, Nubia Inocencya Pavesi; Pascotto, Renata Correa

2012-01-01

67

Modification of single-crystal sapphire by ion implantation  

Microsoft Academic Search

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

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

1997-01-01

68

Tooth Problems  

MedlinePLUS

MENU Return to Web version Tooth Problems See complete list of charts. A tooth that causes ongoing pain may be a sign of a serious problem. Use ... you have an injury that knocked out a tooth? Yes You have TOOTH LOSS. DENTAL EMERGENCY See ...

69

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

PubMed Central

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

Moslehifard, Elnaz; Farid, Farzaneh

2014-01-01

70

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

NASA Astrophysics Data System (ADS)

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.

Satoh, Shu; Yoon, Jongyoon; David, Jonathan

2011-01-01

71

Tooth Numbering  

MedlinePLUS

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

72

Tooth Disorders  

MedlinePLUS

... made of a hard, bonelike material. Inside the tooth are nerves and blood vessels. You need your ... These include eating, speaking and even smiling. But tooth disorders are nothing to smile about. They include ...

73

A Single Histrelin Implant Is Effective for 2 Years for Treatment of Central Precocious Puberty  

PubMed Central

We investigated whether a “yearly” histrelin implant would provide pubertal suppression when left in place for 2 years. Equivalent suppression was observed when comparing 12 and 24 months in 33 children with central precocious puberty. A single implant for 2 years reduces cost and number of implant procedures.

Lewis, Katherine A.; Goldyn, Andrea K.; West, Karen W.; Eugster, Erica A.

2014-01-01

74

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

PubMed Central

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

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

2013-01-01

75

Comparison of tooth displacement between buccal mini-implants and palatal plate anchorage for molar distalization: a finite element study.  

PubMed

The purposes of this study were to mechanically evaluate distalization modalities through the application of skeletal anchorage using finite element analysis. Base models were constructed from commercial teeth models. A finite element model was created and three treatment modalities were modified to make 10 models. Modalities 1 and 2 placed mini-implants in the buccal side, and modality 3 placed a plate on the palatal side. Distalization with the palatal plate in modality 3 showed bodily molar movement and insignificant displacement of the incisors. Placing mini-implants on the buccal side in modalities 1 and 2 caused the first molar to be distally tipped and extruded, while the incisors were labially flared and intruded. Distalization with the palatal plate rather than mini-implants on the buccal side provided bodily molar movement without tipping or extrusion. It is recommended to use our findings as a clinical guide for the application of skeletal anchorage devices for molar distalization. PMID:22051536

Yu, Il-Jun; Kook, Yoon-Ah; Sung, Sang-Jin; Lee, Kee-Joon; Chun, Youn-Sic; Mo, Sung-Seo

2011-11-01

76

[Implants: where, when, how, why?].  

PubMed

The concept of osseointegration which means direct contact between bone and implant has provided new possibilities for implantology and a much more serious approach of the method. Implants are placed following a two phases schedule: first a surgical procedure with a sophisticated insertion of the implants and 3 to 6 months later a prosthetic procedure. Implants can be used in many applications: single tooth replacement, partial and total edentulism. Osseous grafts can be added if needed. Connected and non-connected bridges are built on implants with a tendency to use more non-connected bridges. If all the conditions of placement of the implants and of realisation of the prosthetic supra-structures are respected, there are very few complications. Implants are actually the unique possibility to give the patient fixed oral rehabilitation while preserving the remaining bone and teeth. PMID:2077575

Daelemans, P; Malevez, C

1990-01-01

77

Creating a Single-Visit, Fibre-Reinforced, Composite Resin Bridge by Using a Natural Tooth Pontic: A Viable Alternative to a PFM Bridge.  

PubMed

Background: The rehabilitation of an anterior tooth space presents a confronting situation. Several modalities are presently available to address the challenge of an immediate replacement of a missing anterior tooth. These include a removable temporary acrylic prosthesis or resin-bonded bridges. Fibre-Reinforced Composite (FRC) bridges are preferable if they are fixed and if a cost-effective tooth replacement is desired. Also, they provide an aesthetic and a conservative treatment choice as the abutment teeth require a minimal or no preparation. Methods: This article is describing two cases with an immediate replacement of the maxillary incisor teeth by a single visit technique, with the use of FRC Resin (Ribbond) bridges and natural tooth crowns as pontics. Results and Conclusions: The procedure was completed at the chair side, thereby avoiding the laboratory costs. A two year follow up of the cases has shown a successful outcome. Creating an adhesive FRC bridge by using a natural tooth pontic is a successful treatment option for the direct aesthetic replacement of missing anterior teeth. PMID:23730674

Khetarpal, Ambica; Talwar, Sangeeta; Verma, Mahesh

2013-04-01

78

Creating a Single-Visit, Fibre-Reinforced, Composite Resin Bridge by Using a Natural Tooth Pontic: A Viable Alternative to a PFM Bridge  

PubMed Central

Background: The rehabilitation of an anterior tooth space presents a confronting situation. Several modalities are presently available to address the challenge of an immediate replacement of a missing anterior tooth. These include a removable temporary acrylic prosthesis or resin-bonded bridges. Fibre-Reinforced Composite (FRC) bridges are preferable if they are fixed and if a cost-effective tooth replacement is desired. Also, they provide an aesthetic and a conservative treatment choice as the abutment teeth require a minimal or no preparation. Methods: This article is describing two cases with an immediate replacement of the maxillary incisor teeth by a single visit technique, with the use of FRC Resin (Ribbond) bridges and natural tooth crowns as pontics. Results and Conclusions: The procedure was completed at the chair side, thereby avoiding the laboratory costs. A two year follow up of the cases has shown a successful outcome. Creating an adhesive FRC bridge by using a natural tooth pontic is a successful treatment option for the direct aesthetic replacement of missing anterior teeth.

Khetarpal, Ambica; Talwar, Sangeeta; Verma, Mahesh

2013-01-01

79

Implants  

MedlinePLUS

... root-form implants were placed in people. Other types of implants also have been used for the last 30 to 40 years. Many implant systems are available from various dental manufacturers. Success Studies ...

80

Molecular strategies for pre-implantation genetic diagnosis of single gene and chromosomal disorders.  

PubMed

Pre-implantation genetic diagnosis is used to analyse pre-implantation stage embryos or oocytes for genetic defects, generally for severe Mendelian disorders and chromosome abnormalities. New but controversial indications for pre-implantation genetic diagnosis include identifying human leukocyte antigen compatible embryos suitable as donor, sex selection and adult-onset disorders, particularly cancer. Pre-implantation genetic screening is a variant of pre-implantation genetic diagnosis to improve outcomes of in-vitro fertilisation. Array comparative genomic hybridisation is replacing fluorescence in-situ hybridisation for aneuploidy screening. Besides technical advancement of array platform, the success of pre-implantation genetic screening is strongly related to the embryonic biological nature of chromosomal mosaicism. Having been applied for more than 20 years, pre-implantation genetic diagnosis is recognised as an important alternative to prenatal diagnosis. Diagnosis from a single cell, however, remains a technically challenging procedure, and the risk of misdiagnosis cannot be eliminated. PMID:22858134

Jiang, Boran; Tan, Arnold S C; Chong, Samuel S

2012-10-01

81

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

PubMed Central

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

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

2010-01-01

82

One abutment-one time versus a provisional abutment in immediately loaded post-extractive single implants: A 1-year follow-up of a multicentre randomised controlled trial.  

PubMed

Purpose: To compare immediately loaded post-extractive single implants using a definitive abutment versus provisional abutment later replaced by custom-made abutment. Materials and methods: In two private clinics, 28 patients in need of one single post-extractive implant in the maxilla or mandible from the left second premolar to the right second premolar area were randomised shortly before tooth extraction to provisional abutment (PA) and definitive abutment (DA) groups. Three patients had to be excluded for buccal wall fracture after tooth extraction. In the PA group, implants were immediately restored using a platform-switched provisional titanium abutment and definitive platform-switched titanium abutments were used in the DA group. In both groups, a non-occluding provisional single crown was provided. Implants were definitively restored after 4 months. In the PA group, the abutment was removed and the impression was made directly on the implant platform. In the DA group an impression of the abutment was made using a retraction cord. Outcome measures were: implant failures; complications; and marginal peri-implant bone level changes. Patients were followed up to 1 year after loading. Results: Twelve patients were randomised to the DA group and 13 patients to the PA group. At the 12-month follow-up, no implant failed. One biological complication occurred in the DA group and one mechanical complication occurred in the PA group. All complications were successfully treated. One year after loading, implants in the DA group lost an average of 0.11 mm (SD: 0.06) of periimplant bone and implants in PA group about 0.58 mm (SD: 0.11). At the 12-month follow-up, there was a statistically significant difference in bone level change between groups (mean difference: 0.48 mm, CI 95% 0.40; 0.55, P < 0.0001). Conclusions: Within the limits of this study, the non-removal of abutments placed at the time of surgery resulted in the maintenance of 0.5 mm more bone levels around immediately restored postextractive single implants than repeated abutment removal, although this amount of bone maintenance may not have a clinical impact. Conflicts of interest notification: Dr Tommaso Grandi and Dr Paolo Guazzi serve as consultants for JDentalCare. This study was completely self-financed and no funding was sought or obtained, not even in the form of free materials. PMID:24977249

Grandi, Tommaso; Guazzi, Paolo; Samarani, Rawad; Maghaireh, Hassan; Grandi, Giovanni

2014-01-01

83

Tooth Discoloration  

MedlinePLUS

... from your dentist, but they will lighten your teeth over time. Whitening toothpastes may remove minor stains. They do not actually change the overall color of your teeth. If your tooth has darkened after a root ...

84

Tooth Extraction  

MedlinePLUS

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

85

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

Microsoft Academic Search

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

Giampiero Cordioli; Zeina Majzoub; Stefano Castagna

1997-01-01

86

Characterization of Charging Control of a Single Wafer High Current Spot Beam Implanter  

SciTech Connect

This paper focuses on the characterization of charging control of an Axcelis Optima HD single wafer high current spot beam implanter using MOS capacitors with attached antennas of different size and shape. Resist patterns are implemented on Infineon Technologies own charging control wafers to investigate the influence of photo resist on charging damage. Compared to batch high current implanters the design of the beamline and the beam shape are comparable to single wafer high current spot beam implanters, however due to the different scanning architecture the dose rate of the single wafer high current spot beam implanters is significantly higher compared to the batch tools. Therefore, the risk of charging damage will be higher. The charging damage was studied as a function of the energy, the beam current and the most important plasma flood gun parameters. The results have shown that for very high antenna ratios the charging damage for single wafer implanters, even spot or ribbon beam implanters, is higher than for high current batch implanters.

Schmeide, Matthias; Bukethal, Christoph [Infineon Technologies Dresden GmbH and Co. OHG, Koenigsbruecker Str. 180, D-01099 Dresden (Germany)

2008-11-03

87

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

SciTech Connect

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

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

2011-02-01

88

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

Microsoft Academic Search

The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated\\u000a zirconia implant abutments (ZirDesign™; Astra Tech, Mölndal, Sweden) supporting anterior single crowns (SCs). Four different\\u000a test groups (n?=?8) representing anterior SCs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position\\u000a (left central incisor)

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

2011-01-01

89

Optical properties of metallic nanoparticles in Ni-ion-implanted ?-Al2O3 single crystals  

Microsoft Academic Search

64 keV Ni ion implantation was performed at room temperature up to a dose of 1×1017 cm?2 in ?-Al2O3 single crystals. The charge states, structure, and optical properties of metallic embedded Ni nanoparticles were studied by using x-ray photoelectron spectroscopy (XPS), transmission electron microscopy, and optical spectroscopy, respectively. XPS analysis showed that implanted Ni ions are mainly in charge state

X. Xiang; X. T. Zu; S. Zhu; L. M. Wang

2004-01-01

90

Integration of Single Ion Implantation Method in Focused Ion Beam System for Nanofabrication  

Microsoft Academic Search

A method of single ion implantation based on the online detection of individual ion impacts on a pure silicon substrate has been implemented in a focused ion beam (FIB) system. The optimized silicon detector integrated with a state-of-art low noise electronic system and operated at a low temperature makes it possible to achieve single ion detection with a minimum energy

Changyi Yang; David N. Jamieson; Sean Hearne; Toby Hopf; Chris Pakes; S teven Prawer; Søren E. Andresen; Andrew Dzurak; E. Gauja; F. E. Hudson; R. G. Clark

2006-01-01

91

Comparison of migration behavior between single and dual lag screw implants for intertrochanteric fracture fixation  

PubMed Central

Background Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evaluated in surrogate specimens using an established laboratory model of hip screw cut-out failure. Methods Five dual lag screw implants (Endovis, Citieffe) and five single lag screw implants (DHS, Synthes) were tested in the Hip Implant Performance Simulator (HIPS) of the Legacy Biomechanics Laboratory. This model simulated osteoporotic bone, an unstable fracture, and biaxial rocking motion representative of hip loading during normal gait. All constructs were loaded up to 20,000 cycles of 1.45 kN peak magnitude under biaxial rocking motion. The migration kinematics was continuously monitored with 6-degrees of freedom motion tracking system and the number of cycles to implant cut-out was recorded. Results The dual lag screw implant exhibited significantly less migration and sustained more loading cycles in comparison to the DHS single lag screw. All DHS constructs failed before 20,000 cycles, on average at 6,638 ± 2,837 cycles either by cut-out or permanent screw bending. At failure, DHS constructs exhibited 10.8 ± 2.3° varus collapse and 15.5 ± 9.5° rotation around the lag screw axis. Four out of five dual screws constructs sustained 20,000 loading cycles. One dual screw specimens sustained cut-out by medial migration of the distal screw after 10,054 cycles. At test end, varus collapse and neck rotation in dual screws implants advanced to 3.7 ± 1.7° and 1.6 ± 1.0°, respectively. Conclusion The single and double lag screw implants demonstrated a significantly different migration resistance in surrogate specimens under gait loading simulation with the HIPS model. In this model, the double screw construct provided significantly greater resistance against varus collapse and neck rotation in comparison to a standard DHS lag screw implant.

Kouvidis, George K; Sommers, Mark B; Giannoudis, Peter V; Katonis, Pavlos G; Bottlang, Michael

2009-01-01

92

Tooth Whitening  

MedlinePLUS

... whitening is most effective on surface (extrinsic) stains. Preparation Other dental problems can affect the success of tooth whitening. For example, cavities need to be treated before teeth are whitened. That's because the whitening solution can pass through decayed areas and reach the ...

93

Agenesis of maxillary lateral incisor and tooth replacement: cost-effectiveness of different treatment alternatives.  

PubMed

Purpose: To evaluate the long-term cost-effectiveness of five treatment alternatives for maxillary lateral incisor agenesis where space maintenance and tooth replacement are indicated. Materials and Methods: The following treatment modalities were considered: single-tooth implant-supported crown, resin-bonded fixed partial denture (FPD), cantilever FPD, full-coverage FPD, and autotransplantation. The cost-effectiveness for each treatment modality was determined as the ratio of the outcome of each modality divided by the cost. Direct costs, clinical and laboratory, were calculated based on national fee schedules and converted to international dollars using purchasing power parity exchange rates. Outcomes were based on the most recently published long-term (10-year) survival rates. Sensitivity analyses were carried out, testing the robustness of the cost-effectiveness analysis. Results: The five treatment modalities ranked in the following order from most to least cost-effective: autotransplantation, cantilever FPDs, resin-bonded FPDs, single-tooth implants and implant-supported crowns, and full-coverage FPDs. Sensitivity analysis illustrated that the cost-effectiveness analysis was reliable in identifying autotransplantation as the most and full-coverage FPDs as the least cost-effective treatment modalities. Conclusions: When replacing a missing maxillary lateral incisor, the most costeffective, long-term treatment modality is autotransplantation, whereas the least cost-effective is full-coverage FPDs. However, factors such as patient age, the state of the dentition, occlusion, and tooth conservation should also influence the choice of restoration. PMID:24905267

Antonarakis, Gregory S; Prevezanos, Panagiotis; Gavric, Jelena; Christou, Panagiotis

2014-01-01

94

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

SciTech Connect

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 the silicon wafer initially react with water to produce a negatively charged surface containing the functional group ({identical_to}Si-O{sup -}) that subsequently induces the formation of apatite. A good understanding of the formation mechanism of apatite on hydrogen implanted silicon is not only important from the viewpoint of biophysics but also vital to the actual use of silicon-based microchips and MEMS inside a human body.

Liu Xuanyong; Fu, Ricky K.Y.; Chu, Paul K.; Ding Chuanxian [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

2004-10-18

95

Single-walled carbon nanotube growth from ion implanted Fe catalyst  

NASA Astrophysics Data System (ADS)

The authors present experimental evidence that single-walled carbon nanotubes can be grown by chemical vapor deposition from ion implanted iron catalyst. They systematically characterize the effect of ion implantation dose and energy on the catalyst nanoparticles and nanotubes formed at 900 °C. They also fabricate a micromachined silicon grid for direct transmission electron microscopy characterization of the as-grown nanotubes. This work opens up the possibility of controlling the origin of single-walled nanotubes at the nanometer scale and of integrating them into nonplanar three-dimensional device structures with precise dose control.

Choi, Yongho; Sippel-Oakley, Jennifer; Ural, Ant

2006-10-01

96

Digital subtraction radiography evaluation of longitudinal bone density changes around immediate loading implants: a pilot study  

PubMed Central

Objective The aim of this study was to assess longitudinal quantitative changes in bone density around different implant loading protocols and implant surfaces measured by digital subtraction radiography (DSR). Methods 12 patients received bilateral homologous standard and TiUnite® (Nobel Biocare, Kloten, Switzerland) single-tooth implants under 2 implant—loading protocols: immediate loading (8 patients, 16 implants, 12 maxillary) and conventional loading (4 patients, 8 implants, 4 maxillary). Standardized periapical radiographs were taken immediately after implant placement (baseline image) and at the 3-month, 6-month and 12-month follow ups. Radiographic images were digitized and submitted to digital subtraction using the DSR system® (Electro Medical System, Nyon, Switzerland), resulting in three subtracted images. Quantitative analysis of bone density was performed using Image Tool® software (University of Texas Health Science Centre, San Antonio, TX) to assess pixel value changes in five areas around the implants (crestal, subcrestal, medial third, apical–lateral and apical). Results Repeated-measures analysis of variance showed that grey levels were significantly influenced by follow-up time and implant-loading protocol. A linear increase in grey levels was found for immediate loading (IML) implants and a significant decrease in grey levels was observed in the 12-month follow up for conventional loading implants. No effect of implant surface treatment was observed. Conclusion In conclusion, IML protocol induced mineral bone gain around single-tooth implants after the first year under function for cases with favourable bone conditions.

Carneiro, LS; da Cunha, HA; Leles, CR; Mendonca, EF

2012-01-01

97

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

98

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

99

Introduction of the SHX-III System, a Single-Wafer High-Current Ion Implanter  

NASA Astrophysics Data System (ADS)

The SHX-III system, categorized as a single-wafer high-current ion implanter, has been developed by SEN Corporation in order to meet all the requirements for high dose and relatively high mid-dose applications, including high-tilted multi-step implantation. Recently the three major advanced device types, namely logic devices, memory and imagers, started to require high-current ion implanters in diverse ways. The SHX-III is designed to fulfill such a variety of requirements in one system. The SHX-III has the same end station as the MC3-II/WR, SEN's latest medium current implanter, which has a mechanical throughput of 450 WPH. This capability and precise dose control system of the SHX-III causes dramatic productivity enhancement for application of mid-high dose, ranged between 5E13 to 2E14 atoms/cm2, usually performed by medium current ion implanters. In this paper the concept and performance of the SHX-III will be described, concerning influence of device characteristics. A concept and performance data of the SHX figure that this system can provide implant quality and productivity as far as the 32 nm node.

Sugitani, Michiro; Tsukihara, Mitsukuni; Kabasawa, Mitsuaki; Ishikawa, Koji; Murooka, Hiroki; Ueno, Kazuyoshi

2008-11-01

100

Single-chip CMOS image sensors for a retina implant system  

Microsoft Academic Search

This work describes the architecture and realization of microelectronic components for a retina-implant system that will provide visual sensations to patients suffering from photoreceptor degeneration. Special circuitry has been developed for a fast single-chip CMOS image sensor system, which provides high dynamic range of more than seven decades (without any electronic or mechanical shutter) corresponding to the performance of the

Markus Schwarz; Ralf Hauschild; Bedrich J. Hosticka; J. Huppertz; T. Kneip; S. Kolnsberg; L. Ewe; Hoc Khiem Trieu

1999-01-01

101

High single mode operation from hybrid ion implanted\\/selectively oxidized VCSELs  

Microsoft Academic Search

Summary form only given. The modal discrimination can be augmented by creating a central region of gain surrounded by a region of optical loss. We report single mode output of more than 5 mW for 850 nm VCSELs fabricated using a hybrid ion implantation and selective oxidation device structure designed to achieve this end

K. D. Choquette; A. J. Fischer; K. M. Geib; G. R. Hadley; A. A. Allerman; J. J. Hindi

2000-01-01

102

Seal Out Tooth Decay  

MedlinePLUS

... Home > OralHealth > Topics > Tooth Decay (Caries) Seal Out Tooth Decay What are dental sealants? How are sealants put ... fix decayed teeth. Back to Top What causes tooth decay? Germs in the mouth use the sugar in ...

103

Tooth - abnormal colors  

MedlinePLUS

Abnormal tooth color is any color other than the white to yellowish-white of normal teeth. ... things can cause tooth discoloration. The change in color may affect the entire tooth, or just appear ...

104

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

105

The effect of flash lamp annealing on Fe implanted ZnO single crystals  

SciTech Connect

The effect of flash lamp annealing applied to ZnO single crystals implanted with 3.6 at. % Fe has been studied. For intermediate light power, the implantation-induced surface defects could be annealed without creation of secondary phases within the implanted region. At the same annealing temperatures, however, ion-beam-induced open volume defects start to increase in size. Recrystallization is initiated for the highest light power applied, i.e., the ion-beam-induced lattice disorder reflected by the minimum channeling yield of Rutherford backscattering spectroscopy decreases from 76% to 46% and the open volume defects are annealed. At the same time, the Fe{sup 3+} fraction increases at the cost of the Fe{sup 2+} states. Weak ferromagnetic properties that are mainly associated with nanoparticles are induced.

Potzger, K.; Anwand, W.; Reuther, H.; Zhou, Shengqiang; Talut, G.; Brauer, G.; Skorupa, W.; Fassbender, J. [Institute of Ion Beam Physics and Materials Research, Forschungszentrum Rossendorf, P.O. Box 510119, 01314 Dresden (Germany)

2007-02-01

106

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

PubMed

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

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

2014-08-01

107

Electrical and photoluminescence properties of carbon implanted ZnO bulk single crystals  

NASA Astrophysics Data System (ADS)

Carbon-ions, which are expected as an amphoteric impurity, are implanted into ZnO bulk single crystals with a fluence of 1.5 × 10 15 cm -2. The carbon-ion implanted ZnO shows the n-type conductivity and the resistivity varies from 6 × 10 4 ? cm (for unimplanted samples) to 3 × 10 -2 ? cm (for 800 °C-annealed ones). The Rutherford backscattering (RBS) studies show the existence of the displaced zinc atoms. In photoluminescence (PL) measurements, the broad emission at 2.34 eV observed in un-implanted and as-implanted samples is related to oxygen vacancy and zinc interstitial. After annealing, the weak PL-emission related to carbon donor is observed at 3.06 eV, indicating that the donor level lies at ˜310 meV below the conduction band. The carbon-ion implanted ZnO layer with the low resistivity achieved in the present study suggests the possibility of transparent conductive oxide.

Matsumoto, K.; Kuriyama, K.; Kushida, K.

2009-05-01

108

Stability of ion implanted single-walled carbon nanotubes: Thermogravimetric and Raman analysis  

SciTech Connect

In this work, the effect of different ions (hydrogen, helium, and neon) implanted on single-walled carbon nanotube (SWNT) is being analyzed using thermogravimetric analysis (TGA), Raman scattering, and x-ray photoelectron spectroscopy (XPS). The TGA result shows that the temperature for maximum decomposition rate (T{sub max}) increases at relatively low doses, i.e., by about 30 deg. C after hydrogen ion implantation (at the ion dose of 10{sup 15} cm{sup -2}), 17 deg. C after helium ion implantation (at the ion dose of 10{sup 13} cm{sup -2}), and contributes no significant enhancement after neon implantation for all doses. The increase of T{sub max} indicates that small mass ion can be utilized to improve the thermal-oxidative stability of SWNTs. Raman scattering and XPS were used to monitor the lattice damage from ion implantation and chemical bonding states of the materials. The results indicated the material rigidity for low doses of hydrogen and helium, while the application of higher doses of neon caused the material to transform towards amorphous carbon (a-C)

Adhikari, Ananta R.; Huang Mengbing; Bakhru, Hassaram; Vajtai, Robert; Ryu, Chang Y.; Ajayan, Pulickel M. [College of Nanoscale Science and Engineering, State University of New York, Albany, New York 12203 (United States); Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Department of Material Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 and Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2006-09-15

109

[Dental implants. History and tissue reactions of implants].  

PubMed

Dental implant (oral implant) is totally based on dentistry and the progress in its technology. On this occasion, dental implant are described from the standpoints of experimental pathology and clinical pathology. Demands for improved dental technology have brought significant developments in the dental implant field. Based upon the latest general implant technology, improvements in dental implant technology have primarily taken the form of better materials and designs historically. The object of these developments has been to provide the patients with restored teeth whose structure and function are asymptotically close to those of natural teeth while enhancing recovery of the occlusion function and improving aesthetic quality by means of applying technique of oral surgery (including periodontics) and prosthodontics. The basic structure of the dental implant consists of the substructure buried in the jaw bone, the junction, and the superstructure projected into the oral cavity. These three items correspond respectively to the root, the neck, and the crown of a natural tooth. However, neither the structure nor the function of such an implant body can be identical to those of a natural standing tooth. Physiologic metabolism, which is present in the latter, does not exist in the former. Therefore, it should always be remembered that even modern technology and materials can not reproduce the oral conditions identical to those produced by physiologic tissue and functions which are subject to chronological change. We should bear in mind that this system, unlike those made up by inter-material relations or inter-organic relations is made of an artificial structure, functions apart from the natural organs, and serves only as a substitute. Certain inherently unstable factors are inevitable. For example, radiographic findings confirm that V-shaped radiolucency by bone resorption in the alveolar bone surrounding the tooth neck is always more extensive than in the case of natural teeth. First study: Histopathological Studies of Tissue Reaction for Implant Materials(Fig. 4-10). This study is a basic experiment to help the development of implant materials used in repairing extraction wounds of teeth and bone defects. It is desirable that the materials should be preservable, easy to process, and with high histocompatibility. Examined materials are DCFF or non-DCFF treated bone matrices (grafts) of rats and human, and single crystal ceramics (Al2O3). DCFF treatment is a procedure of decalcifying, defatting and freeze-drying bones and ligaments of animals after fixation in formalin for immunological tolerance (M. KATAGIRI got a patent for this invention in America, West Germany and Japan, Table 1).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2489285

Katagiri, M

1989-10-01

110

Magnetic nano-particles of Ni in MgO single crystals by ion implantation  

Microsoft Academic Search

Magnetic Ni nano-particles in the near surface regions of MgO single crystals have been synthesized by 64keV Ni ion implantation to 1×1017cm?2 followed by thermal annealing. Transmission electron microscopy (TEM) and magnetic properties measurement system (MPMS) equipped with a superconducting quantum interference device (SQUID) detector have been employed to characterize the microstructure and magnetic properties of the Ni nano-particles. The

S. Zhu; X. Xiang; X. T. Zu; L. M. Wang

2006-01-01

111

Magnetic nano-particles of Ni in MgO single crystals by ion implantation  

Microsoft Academic Search

Magnetic Ni nano-particles in the near surface regions of MgO single crystals have been synthesized by 64 keV Ni ion implantation to 1 × 1017 cm-2 followed by thermal annealing. Transmission electron microscopy (TEM) and magnetic properties measurement system (MPMS) equipped with a superconducting quantum interference device (SQUID) detector have been employed to characterize the microstructure and magnetic properties of

S. Zhu; X. Xiang; X. T. Zu; L. M. Wang

2006-01-01

112

Central stentoplasty: technique for unipedicular single midline vertebral body stent implantation.  

PubMed

Vertebral body stenting, or stentoplasty, is a novel percutaneous option in spinal cement augmentation. Conventional stentoplasty requires insertion of two paramedian stents per vertebral body through a bipedicular approach. We developed an unipedicular approach in which we implant a single stent into the midline of the vertebral body using cone-beam CT guidance and hereby describe the technical details and feasibility, in this technique that we termed "central stentoplasty." PMID:24722893

Pua, Uei; Quek, Lawrence Hwee Han; Ng, Leslie Chong Lich

2014-06-01

113

Differences in Masticatory Function in Patients with Endodontically Treated Teeth and Single-implant–supported Prostheses: A Pilot Study  

Microsoft Academic Search

Endodontic treatment and dental implants are both viable treatment options to restore a compromised dentition. How these treatments impact patients' ability to chew has not been studied. The purpose of this study was to compare various parameters of masticatory function in patients with endodontically treated teeth and single-implant supported prostheses. Fifty patients were included in this study. Twenty-five patients had

Karl F. Woodmansey; Murat Ayik; Peter H. Buschang; Cathy A. White; Jianing He

2009-01-01

114

PAC Studies of Implanted 111Ag in Single-Crystalline ZnO  

NASA Astrophysics Data System (ADS)

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

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

2004-11-01

115

Chromium single-photon emitters in diamond fabricated by ion implantation  

NASA Astrophysics Data System (ADS)

Controlled fabrication and identification of bright single-photon emitters is at the heart of quantum optics. Here we demonstrate controlled engineering of a chromium bright single-photon source in bulk diamond by ion implantation. The Cr center has fully polarized emission with a zero-phonon line centered at 749 nm, full width at half maximum of 4 nm, an extremely short lifetime of ˜1ns , and a count rate of 0.5×106counts/s . By combining the polarization measurements and the vibronic spectra, a model of the center has been proposed consisting of one interstitial chromium atom with a transition dipole along one of the ?100? directions.

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

2010-03-01

116

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

NASA Astrophysics Data System (ADS)

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.

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

117

Nano-X-ray absorption spectroscopy of single Co-implanted ZnO nanowires.  

PubMed

We report on the local structure of single Co-implanted ZnO nanowires studied using a hard X-ray nanoprobe. X-ray fluorescence maps show uniform Zn and Co distributions along the wire within the length scale of the beam size. The X-ray fluorescence data allow the estimation of the Co content within the nanowire. Polarization dependent X-ray absorption near edge structure shows no structural disorder induced neither in the radial nor axial directions of the implanted nanowires after subsequent annealing. Co2+ ions occupy Zn sites into the wurtzite ZnO lattice. Extended X-ray absorption fine structure data reveal high structural order in the host lattice without distortion in their interatomic distances, confirming the recovery of the radiation damaged ZnO structure through thermal annealing. PMID:22007972

Segura-Ruiz, J; Martínez-Criado, G; Chu, M H; Geburt, S; Ronning, C

2011-12-14

118

Immediate functional loading of single implants: A 1-year interim report of a 5-year prospective multicentre study.  

PubMed

Purpose: The aim of this prospective multicentre study was to evaluate the clinical outcome of immediately loaded single implants. Materials and methods: Patients were recruited at six clinical centres. Inclusion criteria were singletooth replacement in fully healed sites or post-extraction sockets with adequate bone height and width, to place an implant of at least 3.5 mm in diameter and 10.0 mm in length. All implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were functionally loaded immediately after placement. After 3 months, final crowns were delivered. All implants were followed for 1 year. Outcome measures were: implant stability; complications; peri-implant marginal bone level changes; probing pocket depth. Results: Fifty-seven implants (38 in the maxilla and 19 in the mandible) were placed in 46 patients (23 males, 23 females, aged between 18 to 73 years). Ten implants were placed in post-extraction sockets. Two patients (two implants) withdrew from the study and were classified as drop-outs. At the end of the study, only one implant was lost in a healed site. All the surviving implants were stable, giving an overall 1-year survival rate of 97.7% (patient-based). A few complications (one patient experienced swelling after surgery, two had loosened abutments and another patient had a ceramic crown fracture) were encountered. After 1 year of functional loading, the patients had lost an average of 0.32 mm (± 0.22) of peri-implant marginal bone; the mean probing pocket depth (PPD) was 2.16 mm (± 0.68). Conclusions: Within its limit (limited number of patients treated and self-evaluation of the outcomes), this study supports the concept that immediate functional loading of single dental implants can be a successful treatment procedure, with satisfactory clinical outcomes. Conflict-of-interest statement: MegaGen Implant Co., Gyeongbuk, South Korea, the manufacturer of the implants used in this investigation, partially supported this study by donating the implants and prosthetic components; however, the research data belonged to the authors and by no means did Megagen interfere with the conduct of the study or the publication of the results. PMID:24977254

Luongo, Giuseppe; Lenzi, Carolina; Raes, Filiep; Eccellente, Tammaro; Ortolani, Michele; Mangano, Carlo

2014-01-01

119

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

PubMed Central

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

Galvin, John J.; Oba, Sandy; Fu, Qian-Jie; Baskent, Deniz

2014-01-01

120

Preparation of C 60 single crystalline thin film by ionized cluster beam deposition and ion implantation into single crystalline C 60 thin film  

NASA Astrophysics Data System (ADS)

We have succeeded in preparing single crystalline C 60 thin film of a lateral extension in the order of several millimeters on mica by ionized cluster beam (ICB) deposition. During the growth process, planar dendrite-like single crystalline islands were observed by an atomic force microscope (AFM). It was concluded from reflection high-energy electron diffraction (RHEED) and transmission electron diffraction (TED) analyses that these islands grow hetero-epitaxially on mica. As the deposition process continues, the single crystalline islands coalesce and finally form a giant single crystal without grain boundaries between the former islands. This layered dendrite-like crystal growth is considered to be due to the ICB process, namely, ionizing molecules and accelerating them. Furthermore, the effect of ion (P +, B +, Ar +) implantation into C 60 thin films on the molecular structure and the conductivity has been studied under various implantation conditions. It was found from the analyses of FT-IR and Raman spectroscopies that the soccer-ball-like structure of C 60 changes into a diamond-like carbon (DLC) structure with an implantation energy higher than 40 keV, whereas the structure undergoes virtually no change with 10 keV implantation. As for conductivity changes under the lower implantation energy condition, the minimum dose of P + ions required to increase the conductivity from the non-doped value (10 12 cm -2) is 10 times lower than in the case of Ar + implantation. The conductivity change for the P + implantation could be explained satisfactorily not only by the effect of chemically-modified C 60 but also by the effect of a charge-transfer state between C 60 and implanted ions. It was concluded from these results that the conductivity of the C 60 film can be controlled over a wide range based on the carrier generation mechanism, which depends on the implantation conditions.

Isoda, Satoru; Kawakubo, Hiroaki; Nishikawa, Satoshi; Wada, Osamu

1996-05-01

121

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

PubMed Central

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

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

2014-01-01

122

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

PubMed

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

Burke, Peter; Rutherglen, Christopher

2010-08-01

123

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

PubMed

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

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

2014-07-01

124

How a Tooth Decays  

MedlinePLUS

Illustrations: How a Tooth Decays 1. Healthy Tooth 2. White Spots Enamel is the hard outer crystal-like layer. Dentin is the softer layer ... the tooth can no longer repair itself. The cavity has to be cleaned and restored by a ...

125

Surfaces of the Tooth  

MedlinePLUS

... tooth. Learn them, and next time your dentist's words may make more sense. Here's how dentists refer to the tooth's surfaces: Buccal or facial or labial — This is the tooth surface that faces the outside of your mouth. It's also what people can see when they ...

126

Fractured tooth (image)  

MedlinePLUS

A tooth can be chipped or fractured during an accident or a bad fall. A tooth that is chipped or not badly fractured can usually be handled on a nonemergency basis. A tooth that is badly fractured may have exposed nerve ...

127

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

128

Optical properties of metallic nanoparticles in Ni-ion-implanted alpha-Al2O3 single crystals  

Microsoft Academic Search

64 keV Ni ion implantation was performed at room temperature up to a dose of 1×1017 cm-2 in alpha-Al2O3 single crystals. The charge states, structure, and optical properties of metallic embedded Ni nanoparticles were studied by using x-ray photoelectron spectroscopy (XPS), transmission electron microscopy, and optical spectroscopy, respectively. XPS analysis showed that implanted Ni ions are mainly in charge state

X. Xiang; X. T. Zu; S. Zhu; L. M. Wang

2004-01-01

129

Ion implantation-caused damage depth profiles in single-crystalline silicon studied by Spectroscopic Ellipsometry and Rutherford Backscattering Spectrometry  

Microsoft Academic Search

Damage created by ion implantation of Ar+ ions into single crystalline silicon is characterized using Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). To create buried disorder, Ar+ ions with an energy of 100 keV were implanted into the samples. Ion doses were varied from 5×1013 atom\\\\cm2 to 6.75×1014 atom\\\\cm2. Damage depth profiles have been investigated using RBS combined with

P Petrik; O Polgár; T Lohner; M Fried; NQ Khánh; J Gyulai

1998-01-01

130

Immediate loading: a new implant technique with immediate loading and aesthetics: Nobel Active(TM)  

PubMed Central

SUMMARY The aim of this study is to evaluate the short time aesthetic and functional outcome of a new implant system, the Nobel Active™. The Nobel Active™ features several innovations such as an extensive self-drilling capacity, axial and radial bone compression and an inward tapered collar allowing for marginal bone maintance an soft tissue stabilization. This design makes it possible to place the implant into narrower osteotomies, thus requiring less drilling, compared to conventional implants. The Nobel Active™ implants are available in two different prosthetic connections: Internal connection and external connection. The Nobel Active™ External connection is a 1.5 piece implant, with a primary abutment included with the implant. The Nobel Active™ internal connection is a two piece implant with a standard hexagonal internal connection. In this study we present a single tooth replacement with immediate loading of Nobel Active External connection.

MORETTO, D.; GARGARI, M.; NORDSJO, E.; GLORIA, F.; OTTRIA, L.

2009-01-01

131

EPR study of Mn-implanted single crystal plates of TiO 2 rutile  

NASA Astrophysics Data System (ADS)

Single crystals of Mn-implanted TiO 2 rutile have been investigated by electron paramagnetic resonance (EPR) technique at room temperature. We have observed an EPR signal on Mn 4+ ions ( S= 3/2) in the manganese-implanted single crystal TiO 2 plates. Besides, weaker EPR signals due to Fe 3+( S= 5/2, L=0) and Cr 3+( S= 3/2) ions have also been observed. Characteristic six-line splitting of the manganese EPR lines due to hyper-fine interaction with 55Mn nuclei (spin I= 5/2) has also been observed. Analysis of the EPR spectra shows that the manganese, iron and chromium ions substitute for Ti 4+ ions in the TiO 2 rutile host. Two structurally equivalent groups of the centers have been observed in the EPR spectra in correspondence with two octahedral positions of the Ti ions in the rutile structure. Spin Hamiltonian parameters for the crystal field of orthorhombic symmetry on the Mn 4+, Fe 3+ and Cr 3+ centers have been obtained as result of computer modelling.

Güler, S.; Rameev, B.; Khaibullin, R. I.; Lopatin, O. N.; Akta?, B.

2010-04-01

132

Ion implantation effects in single crystal Si investigated by Raman spectroscopy  

NASA Astrophysics Data System (ADS)

A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 × 10 13 to 1 × 10 15 ions/cm 2. The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1. Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

Harriman, T. A.; Lucca, D. A.; Lee, J.-K.; Klopfstein, M. J.; Herrmann, K.; Nastasi, M.

2009-05-01

133

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

134

Dental student perceptions of predoctoral implant education and plans for providing implant treatment.  

PubMed

This study aims to identify dental students' perceptions of pre-patient care laboratory exercises (PCLEs) and clinical experiences that influence their future plans for providing implant care. One of two questionnaires was administered to dental student classes at one dental school (D2: Survey 1; D3 and D4: Survey 2). Future plans as graduates to provide implant diagnosis and treatment planning (DxTP), restoration of single-tooth implants (STIs), and implant-retained overdentures (IODs) were cross-sectionally assessed along with potential influences such as PCLE, clinical experiences, gender, and class. The majority of students planned to provide implant services after graduation (DxTP 68.9 percent; STI 61.2 percent; IOD 62.1 percent). Bivariately, males reflected more preparedness from PCLEs than females (p=.002) and the D2 students more than D3 and D4 students (p<.001). Multivariate models revealed the perceived preparedness from PCLEs generally had the strongest association with future plans for performing implant therapy. However, this varied by gender and class. These findings indicate that PCLEs are important for their influence on students' future plans to provide implant therapy. However, further studies are needed to validate actual PCLEs and clinical implant practices (both longitudinally and for other schools) and to determine educational interventions to optimize the provision of implant care. PMID:21642520

Yuan, Judy Chia-Chun; Kaste, Linda M; Lee, Damian J; Harlow, Rand F; Knoernschild, Kent L; Campbell, Stephen D; Sukotjo, Cortino

2011-06-01

135

Implantable cardioverter defibrillator therapy in pediatric and congenital heart disease patients: a single tertiary center experience in Korea  

PubMed Central

Purpose The use of implantable cardioverter defibrillators (ICDs) to prevent sudden cardiac death is increasing in children and adolescents. This study investigated the use of ICDs in children with congenital heart disease. Methods This retrospective study was conducted on the clinical characteristics and effectiveness of ICD implantation at the department of pediatrics of a single tertiary center between 2007 and 2011. Results Fifteen patients underwent ICD implantation. Their mean age at the time of implantation was 14.5±5.4 years (range, 2 to 22 years). The follow-up duration was 28.9±20.4 months. The cause of ICD implantation was cardiac arrest in 7, sustained ventricular tachycardia in 6, and syncope in 2 patients. The underlying disorders were as follows: ionic channelopathy in 6 patients (long QT type 3 in 4, catecholaminergic polymorphic ventricular tachycardia [CPVT] in 1, and J wave syndrome in 1), cardiomyopathy in 5 patients, and postoperative congenital heart disease in 4 patients. ICD coils were implanted in the pericardial space in 2 children (ages 2 and 6 years). Five patients received appropriate ICD shock therapy, and 2 patients received inappropriate shocks due to supraventricular tachycardia. During follow-up, 2 patients required lead dysfunction-related revision. One patient with CPVT suffered from an ICD storm that was resolved using sympathetic denervation surgery. Conclusion The overall ICD outcome was acceptable in most pediatric patients. Early diagnosis and timely ICD implantation are recommended for preventing sudden death in high-risk children and patients with congenital heart disease.

Jin, Bo Kyung; Bang, Ji Seok; Choi, Eun Young; Kim, Gi Beom; Kwon, Bo Sang; Noh, Chung Il; Choi, Jung Yun; Kim, Woong Han

2013-01-01

136

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

PubMed Central

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

Carvi Nievas, Mario N.

2011-01-01

137

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

SciTech Connect

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

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

2006-10-01

138

Nature of Defects Induced by Au Implantation in Hexagonal Silicon Carbide Single Crystals  

SciTech Connect

Pulsed-slow-positron-beam-based positron lifetime spectroscopy was used to investigate the nature of vacancy defects induced by 20 MeV Au implantation in single crystals 6H-SiC. Preliminary analysis of the data shows that at lower fluence, below 10{sup 14} cm{sup -2}, a positron lifetime of 220 ps has been obtained: it could be associated with the divacancy V{sub Si}-V{sub C} in comparison with the literature. At higher fluence, above 10{sup 15} cm{sup -2}, a positron lifetime of 260-270 ps, increasing with the incident positron energy, has been observed after decomposition of the lifetime spectra. By comparison with lifetime calculations, open-volumes such as quadrivacancy (V{sub Si}-V{sub C}){sub 2} clusters could be associated with this value.

Gentils, Aurelie; Barthe, Marie-France [CNRS, CEMHTI Site Cyclotron, 3A rue de la Ferollerie, 45071 Orleans (France); Egger, Werner; Sperr, Peter [Universitaet der Bundeswehr Muenchen, Werner-Heisenberg-Weg 39, 85579 Neubiberg (Germany)

2009-03-10

139

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

PubMed Central

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

2014-01-01

140

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

PubMed Central

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

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

2014-01-01

141

Generation of vacancy cluster-related defects during single MeV silicon ion implantation of silicon  

NASA Astrophysics Data System (ADS)

Deep Level Transient Spectroscopy (DLTS) has been used to study defects formed in bulk silicon after implantation of 8.3 MeV 28Si3+ ions at room temperature. For this study, Schottky diodes prepared from n-type Czohralski-grown silicon wafers have been implanted in the single ion regime up to fluence value of 1 × 1010 cm-2 utilizing the scanning focused ion microbeam as implantation tool and the Ion Beam Induced Current (IBIC) technique for ion counting. Differential DLTS analysis of the vacancy-rich region in self-implanted silicon reveals a formation of the broad vacancy-related defect state(s) at Ec -0.4 eV. Direct measurements of the electron capture kinetics associated with this trap at Ec -0.4 eV, prior to any annealing do not show an exponential behaviour typical for the simple point-like defects. The logarithmic capture kinetics is in accordance with the theory of majority carrier capture at extended or cluster-related defects. We have detected formation of two deep electron traps at Ec -0.56 eV and Ec -0.61 eV in the interstitial-rich region of the self-implanted silicon, before any annealing. No DLTS signal originating from vacancy-oxygen trap at Ec -0.17 eV, present in the sample irradiated with 0.8 MeV neutrons, has been recorded in the self-implanted sample.

Pastuovi?, Ž.; Capan, I.; Siegele, R.; Ja?imovi?, R.; Forneris, J.; Cohen, D. D.; Vittone, E.

2014-08-01

142

Single crystalline BaTiO{sub 3} thin films synthesized using ion implantation induced layer transfer  

SciTech Connect

Layer transfer of BaTiO{sub 3} 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 BaTiO{sub 3} single crystals. From thermodynamic equilibrium calculations, we suggest that the dominant species during cavity nucleation and growth are H{sub 2}, H{sup +}, H{sub 2}O, Ba{sup 2+} 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, BaTiO{sub 3} 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 BaTiO{sub 3} thin films were transferred onto amorphous Si{sub 3}N{sub 4} and Pt substrates. Micro-Raman spectroscopy indicated that the density of defects generated by ion implantation in BaTiO{sub 3} 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.

Park, Young-Bae; Diest, Kenneth; Atwater, Harry A. [Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)

2007-10-01

143

Layer morphology and Al implant profiles after annealing of supersaturated, single-crystalline, amorphous, and nanocrystalline SiC  

NASA Astrophysics Data System (ADS)

Al supersaturated SiC layers (5×1020 Al cm-3) were produced by multienergy, high-dose ion implantation into 6H- and 4H-SiC. Several implantation schemes with varying implantation sequence and temperature were investigated. In dependence on the implantation conditions damaged single-crystalline, amorphous, or nanocrystalline layers were formed. The layer morphology and Al distribution in the as-implanted state as well as structural changes and related Al redistribution after high-temperature annealing (1500-1700 °C) were characterized by cross-sectional transmission electron microscopy, Rutherford backscattering spectrometry in combination with ion channeling, atomic force microscopy, and secondary-ion mass spectrometry. Remarkable Al redistribution effects have been found after annealing of Al supersaturated SiC. During high-temperature annealing Al atoms in excess to the solid solubility (2×1020 Al cm-3) tend to precipitate in single-crystalline SiC whereas they diffuse out in amorphous or nanocrystalline SiC. Redistribution of Al with concentration below the solid solubility is governed by transient enhanced diffusion which can be controlled by the annealing scheme. Amorphization of SiC is advantageous in the case of Al doping to levels higher than the solid solubility because it prevents Al precipitation during annealing and helps to form boxlike Al profiles with smooth plateau and abrupt edge.

Heera, V.; Mücklich, A.; Dubois, C.; Voelskow, M.; Skorupa, W.

2004-09-01

144

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

Microsoft Academic Search

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

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

2004-01-01

145

Cochlear implant artifact attenuation in late auditory evoked potentials: a single channel approach.  

PubMed

Recent evidence suggests that late auditory evoked potentials (LAEP) provide a useful objective metric of performance in cochlear implant (CI) subjects. However, the CI produces a large electrical artifact that contaminates LAEP recordings and confounds their interpretation. Independent component analysis (ICA) has been used in combination with multi-channel recordings to effectively remove the artifact. The applicability of the ICA approach is limited when only single channel data are needed or available, as is often the case in both clinical and research settings. Here we developed a single-channel, high sample rate (125 kHz), and high bandwidth (0-100 kHz) acquisition system to reduce the CI stimulation artifact. We identified two different artifacts in the recording: 1) a high frequency artifact reflecting the stimulation pulse rate, and 2) a direct current (DC, or pedestal) artifact that showed a non-linear time varying relationship to pulse amplitude. This relationship was well described by a bivariate polynomial. The high frequency artifact was completely attenuated by a 35 Hz low-pass filter for all subjects (n = 22). The DC artifact could be caused by an impedance mismatch. For 27% of subjects tested, no DC artifact was observed when electrode impedances were balanced to within 1 k?. For the remaining 73% of subjects, the pulse amplitude was used to estimate and then attenuate the DC artifact. Where measurements of pulse amplitude were not available (as with standard low sample rate systems), the DC artifact could be estimated from the stimulus envelope. The present artifact removal approach allows accurate measurement of LAEPs from CI subjects from single channel recordings, increasing their feasibility and utility as an accessible objective measure of CI function. PMID:23727626

Mc Laughlin, Myles; Lopez Valdes, Alejandro; Reilly, Richard B; Zeng, Fan-Gang

2013-08-01

146

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

SciTech Connect

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

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

2011-01-07

147

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

PubMed Central

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

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

2012-01-01

148

Measuring dental drift and orthodontic tooth movement in response to various initial forces in adult rats.  

PubMed

A method for the quantification of orthodontic tooth movement in the rat is presented. Reliability, sensitivity, and validity were assessed and tooth movement kinetics were determined for initial forces of 20, 40, and 60 gm. The appliance consisted of a 9 mm length of closed coil spring suspended between a cleat and bonded to the occlusal surface of the maxillary first molars and the maxillary incisors. Initial tipping forces were placed by suspending known weights from the anterior end of these coils before fixation to the incisors. Tooth movement was quantified from enlarged cephalograms by measuring the position of a reproducible landmark on the molar cleat with respect to either zygomatic amalgam implants or a barbed broach placed submucosally on the palate. All measurements were made along the molar-incisor vector by projecting at 90 degrees to this line. Validity and sensitivity were assessed by quantifying molar distal drift and comparing these results with reports of bone turnover rates adjacent to distally drifting adult rat molars. Reliability was obtained by estimating the error of a single measurement in a longitudinal study of 12 adult male Sprague-Dawley rats (180 to 200 days) receiving both amalgam and broach implants and a cross-sectional study of 72 animals divided equally into six groups to be killed at 1, 3, 5, 7, 10, and 14 days. No orthodontic forces were used in this portion of the study. Implant stability within the craniofacial complex was assessed by measuring bilateral broaches as a function of time with respect to each other. There were no systematic errors between replicate films for either the amalgam or the broach method. The 95% confidence limit for a single determination of molar position was 62 microns using the amalgams and 47 microns for the broach (p less than 0.001). The latter could be reduced to 23 microns when the average of four independent determinations was used. Homologous implants did not differ with respect to each other in the sagittal plane but did in the transverse plane (p less than 0.01), migrating laterally 9 microns/day. Linear regression analysis of molar distal movement over time predicted 7.7 microns/day distal drift (p less than 0.01), which compared favorably with reports of 6.7 microns/day of alveolar bone turnover during this drifting process. Characteristic three-part cumulative tooth movement kinetics were obtained for the 40 and 60 gm initial force groups. No individual time point at 60 gm differed from its counterpart at 40 gm.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2028935

King, G J; Keeling, S D; McCoy, E A; Ward, T H

1991-05-01

149

Lithium ion implantation and annealing of MgO single crystals  

NASA Astrophysics Data System (ADS)

Nominally pure MgO crystals were implanted with lithium ions with different energies and fluences. The defect profile induced by the implantation was primarily characterized by Rutherford backscattering spectrometry and optical absorption measurements. Several absorption bands, associated with oxygen vacancies and higher-order defects involving oxygen, were observed. No evidence was found for the formation of Li colloids during implantation. Thermal annealings in flowing argon at increasing temperatures improved the crystalline quality of the implanted region and induced the appearance of extinction bands associated with Mie scattering from Li colloids. The influence of both intrinsic and extrinsic defects on the formation of precipitates was also investigated in lithium-doped MgO crystals after implantation with Li ions.

Savoini, B.; González, R.; da Silva, R. C.; Alves, E.

2007-04-01

150

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

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. PMID:24316712

Pellicer-Chover, H; Peñarrocha-Oltra, D; Bagán, L; Fichy-Fernandez, A-J; Canullo, L; Peñarrocha-Diago, M

2014-01-01

151

Peri-implant esthetics assessment and management  

PubMed Central

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

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

2013-01-01

152

Tooth Abfraction Lesions  

MedlinePLUS

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

153

Replacing a Missing Tooth  

MedlinePLUS

... and improve speech and appearance until a definitive restoration is made. Is the missing tooth always replaced? ... the bridge are not otherwise in need of restoration, a resin-bonded fixed bridge may be chosen. ...

154

Cracked Tooth Syndrome  

MedlinePLUS

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

155

Tooth decay - early childhood  

MedlinePLUS

Bottle mouth; Bottle carries; Baby bottle tooth decay; Early childhood caries (ECC) ... chap 304. Ribeiro NM, Ribeiro MA. Breastfeeding and early childhood caries: a critical review. J Pediatr (Rio J). ...

156

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

Microsoft Academic Search

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

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

2008-01-01

157

Unilateral Osmotic Swelling in Textured, Single-Lumen, Saline-Filled Mammary Implants: Clinical and MRI Findings  

Microsoft Academic Search

.   An odd complication following routine breast augmentations was observed in two patients. Single-lumen, textured, high-profile,\\u000a saline-filled mammary implants were placed in the submuscular plane and postoperative course was uneventful in the presented\\u000a cases. Unilateral, gradual, and spontaneous swelling in one of the operated breasts was observed 6–14 months after surgery\\u000a that prompted patients for examination. MRI showed regular external

Mehmet Ketene; Aydin Saray; Simay Altan Kara

2002-01-01

158

Nanomechanical characterization of cavity growth and rupture in hydrogen-implanted single-crystal BaTiO{sub 3}  

SciTech Connect

A thermodynamic model of cavity nucleation and growth in ion-implanted single-crystal BaTiO{sub 3} layer is proposed, and cavity formation is related to the measured mechanical properties to better understand hydrogen implantation-induced layer transfer processes for ferroelectric thin films. The critical radius for cavity nucleation was determined experimentally from blistering experiments performed under isochronal anneal conditions and was calculated using continuum mechanical models for deformation and fracture, together with thermodynamic models. Based on thermodynamic modeling, we suggest that cavities grow toward the cracking criteria at a critical blister size whereupon gas is emitted from ruptured cavities. The main driving force for layer splitting is the reduction of the overall elastic energy stored in the implanted region during the cavity nucleation and growth as the gaseous H{sub 2} entrapped within the cavities is released. Nanoindentation measurements reveal locally the mechanical property changes within the vicinity of a single cavity. Using the measured mechanical properties at the single-cavity level, we developed three-dimensional strain and stress profiles using finite element method.

Park, Young-Bae; Nardi, Patrick; Li, Xiaodong; Atwater, Harry A. [Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States); Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, South Carolina 29208 (United States); Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)

2005-04-01

159

Immediate placement of dental implants in the esthetic zone: a systematic review and pooled analysis.  

PubMed

Background: Research interest on immediate placement of dental implants has shifted from implant survival toward optimal preservation of soft and hard tissues. The aim of this study is to systematically assess the condition of implant survival, peri-implant hard and soft tissue changes, esthetic outcome, and patient satisfaction of immediately placed single-tooth implants in the esthetic zone. Methods: MEDLINE, EMBASE, and CENTRAL databases were searched for publications up to June 2013. Studies reporting on implant survival, changes in hard and soft peri-implant tissues, esthetic outcome, and patient satisfaction were considered. A pooled analysis was performed to identify factors associated with survival and peri-implant tissue changes after immediate implant placement. Results: Thirty-four studies were considered eligible. Immediate placement of single-tooth implants in the esthetic zone was accompanied by excellent 1-year implant survival (97.1%, 95% confidence interval [CI]: 0.958 to 0.980). Mean marginal peri-implant bone loss was 0.81 ± 0.48 mm, mean loss of interproximal peri-implant mucosa level was 0.38 ± 0.23 mm, and mean loss of peri-implant midfacial mucosa level was 0.54 ± 0.39 mm. Regression analysis revealed that delayed provisionalization (odds ratio [OR] 58.03, 95% CI: 8.05 to 418.41, P <0.000), use of a flap (OR 19.87, 95% CI: 10.21 to 38.66, P <0.000), and use of a connective tissue graft (OR 4.56, 95% CI: 1.72 to 12.08, P <0.002) were associated with marginal peri-implant bone-level change >0.50 mm. Because of underreporting, esthetic results and patient outcome did not allow for reliable analysis. Conclusion: Immediate placement with immediate provisionalization of dental implants in the esthetic zone results in excellent short-term treatment outcome in terms of implant survival and minimal change of peri-implant soft and hard tissue dimensions. PMID:24502614

Slagter, Kirsten W; den Hartog, Laurens; Bakker, Nicolaas A; Vissink, Arjan; Meijer, Henny J A; Raghoebar, Gerry M

2014-07-01

160

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

PubMed

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

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

2014-05-01

161

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

NASA Astrophysics Data System (ADS)

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

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

2006-09-01

162

Note: Laser ablation technique for electrically contacting a buried implant layer in single crystal diamond  

NASA Astrophysics Data System (ADS)

The creation of thin, buried, and electrically conducting layers within an otherwise insulating diamond by annealed ion implantation damage is well known. Establishing facile electrical contact to the shallow buried layer has been an unmet challenge. We demonstrate a new method, based on laser micro-machining (laser ablation), to make reliable electrical contact to a buried implant layer in diamond. Comparison is made to focused ion beam milling.

Ray, M. P.; Baldwin, J. W.; Feygelson, T. I.; Butler, J. E.; Pate, B. B.

2011-05-01

163

Channeling Analysis of Defects in Indium-Antimonide Single Crystals after Implantation of Beryllium Ions.  

NASA Astrophysics Data System (ADS)

The radiation damage resulting in InSb due to the implantation of Be ions at energies between 50 and 200 keV was studied by means of Rutherford back-scattering and channeling. The radiation dose varied from 5 times 10^{13} to 2 times 10^{16 } ions/cm^2. General conclusions on the nature of the disorder introduced were drawn from the dependence of the radiation damage on the energy of the analysing beam. Some crystals implanted at room temperature with a dose of 1 times 10^ {16} Be^+/cm ^2 at an energy of 100 keV were isochronally annealed. Other crystals were implanted with the same dose and energy, but at elevated substrate temperatures. In both cases the temperature ranged between room temperature and temperatures just below the melting point of InSb. With these different annealing methods a marked difference was obtained in the annealing behaviour of the < 111> as well as the <211> orientations. Pulsed laser and electron beams were also used to anneal radiation damage in InSb crystals that were implanted at room temperature with Be ions at doses between 5 times 10^{15} and 2 times 10^{16 } ions/cm^2. Because of a non-linear dependence between the radiation damage and the energy of the implanted ions, crystals that were implanted at 100 and 200 keV were examined for each dose. The RBS and channeling spectra showed a definite annealing effect, which started at the surface and extended deeper into the crystal with increasing electron or laser energy density. For both methods successful annealing of radiation damage deeper into the crystal was obtained, although the surface melted when laser beam was used. In both annealing methods the successful annealing of the radiation damage depended on the implanted Be dose. InSb crystals that were bombarded with Be ions, electrons or photons, showed an orientation dependent damage. For implantation at higher Be doses it was, however, found that these defect structures were better annealed when electron beam heating was used. Pulsed electron beam annealing was more effective in reordering ion-damaged crystals than pulsed laser beam annealing, isochronal thermal annealing or implantation at elevated substrate temperatures. For implantation at low Be doses conventional furnace annealing seems to be the most suitable method.

Cilliers, Rian

164

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

PubMed

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

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

2012-06-01

165

A New Index of Tooth Wear  

Microsoft Academic Search

A modified wear index, in which the wear of enamel and dentine are recorded separately, is described. The index was applied to estimating the prevalence and extent of tooth wear in a single convenience sample of 18- to 30-year-old students attending a university in London. The subjects were examined under good lighting in a dental chair away from a dental

J. Fares; S. Shirodaria; K. Chiu; N. Ahmad; M. Sherriff; D. Bartlett

2009-01-01

166

Homoepitaxial single crystal diamond grown on natural diamond seeds (type IIa) with boron-implanted layer demonstrating the highest mobility of 1150 cm 2\\/V s at 300 K for ion-implanted diamond  

Microsoft Academic Search

The homoepitaxial single crystal diamond growth by microwave plasma assisted CVD at high microwave power density 200W\\/cm3 in a 2.45GHz MPACVD reactor using natural diamond seeds (type IIa) was investigated. The semiconductor CVD diamond of p-type was obtained by doping technique of ion implantation. Boron ions were implanted at the acceleration energy of 80keV with two cases of dose: 5·1014

A. K. Ratnikova; M. P. Dukhnovsky; Yu. Yu. Fedorov; V. E. Zemlyakov; A. B. Muchnikov; A. L. Vikharev; A. M. Gorbachev; D. B. Radishev; A. A. Altukhov; A. V. Mitenkin

2011-01-01

167

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

NASA Astrophysics Data System (ADS)

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 single programmable logic device that is responsible for performing data reduction on the 96 channels of neural data, providing a bidirectional telemetry interface to a transceiver and performing command interpretation and system supervision. The device takes as input neural data sampled at 31.25 kHz and outputs a line-encoded serial bitstream containing the information to be transmitted by the transceiver. Data can be output in one of the following four modes: (1) streaming uncompressed data from a single channel, (2) extracted spike waveforms from any subset of the 96 channels, (3) 1 ms bincounts for each channel or (4) streaming data along with extracted spikes from a single channel. The device can output up to 2000 extracted spikes per second with latencies suitable for a brain-machine interface application. This device provides all of the digital processing components required by a fully implantable system.

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

2007-09-01

168

Treatment of a patient with cleidocranial dysplasia using a single-stage implant protocol.  

PubMed

This patient report describes the treatment of a 45-year-old Caucasian woman with cleidocranial dysplasia who had significant dental problems that greatly affected her quality of life. The patient had orthodontic treatment in her earlier years along with surgical removal of supernumerary teeth. Using implants, the maxillary and mandibular arches were restored with fixed screw-retained prostheses. Eight implants and six implants were placed in the maxilla and mandible, respectively. Both arches were immediately loaded following the Teeth in a Day™ protocol using an all-acrylic resin provisional prosthesis. Five months later, definitive maxillary and mandibular prostheses were fabricated. The patient has been followed for a period of 5 years, and all postoperative evaluations have been uneventful. PMID:22003879

Petropoulos, Vicki C; Balshi, Thomas J; Wolfinger, Glenn J; Balshi, Stephen F

2011-10-01

169

White Spot (Early Tooth Decay)  

MedlinePLUS

... TMJ Disorders Oral Cancer Dry Mouth Burning Mouth Tooth Decay See All Oral Health Oral Complications of Systemic ... Sorted by ... > Children's Oral Health White Spot Early tooth decay Share This Page Facebook External link – please review ...

170

What Are Tooth Preservation Kits?  

MedlinePLUS

... or Allergies? Find Out Signing Kids Up for Sports Breastfeeding FAQs Pregnant? Your Baby's Growth What Are Tooth Preservation Kits? KidsHealth > Parents > Sports Medicine Center > Q&As > What Are Tooth Preservation ...

171

Effects of crystal defects on the stopping powers for channeled ions in ion implanted single crystals  

Microsoft Academic Search

The ion beam channeling method is used in the study of impurity distribution and implantation damage in crystalline materials. This technique requires knowledge of the stopping power of a channeled ion. Although the stopping powers for non-channeled ions are well established, the energy loss of channeled ions has been studied only in perfect crystals. The energy-loss measurements have been made

E. Kótai

1999-01-01

172

Raman scattering and photoluminescence of As ion-implanted ZnO single crystal  

NASA Astrophysics Data System (ADS)

We have converted the surface of undoped ZnO bulk into the As-doped p-ZnO layer by means of the As ion implantation method. After postimplantation annealing, the As-related properties were investigated by using Raman scattering and photoluminescence (PL) experiments. The Raman spectrum shows that the E2high peak obtained from the As-doped p-ZnO shifted toward the higher energy side of 0.55 cm-1 in comparison with that of the undoped ZnO bulk. This result is related to the stress increment of the sample surface due to the As implantation. After the As-implanted p-ZnO annealed at 800 °C, the PL spectroscopy reveals the neutral acceptor bound exciton emission (A?,X) at 3.3589 eV. This emission shows a tendency to quench the intensity and extend the emission linewidth with increasing temperatures. Also, two As-related peaks associating with recombination emissions between free electrons and acceptor holes were observed at 3.3159 and 3.2364 eV. In addition, the I-V characteristic curves of the p-n homojunction fabricated with the As ion implantation method clearly have shown the behavior of the diode.

Jeong, T. S.; Han, M. S.; Youn, C. J.; Park, Y. S.

2004-07-01

173

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

NASA Astrophysics Data System (ADS)

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

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

2006-05-01

174

Nuclear reaction analysis of Ge ion-implanted ZnO bulk single crystals: The evaluation of the displacement in oxygen lattices  

NASA Astrophysics Data System (ADS)

The displacement of oxygen lattices in Ge ion-implanted ZnO bulk single crystals is studied by nuclear reaction analysis (NAR), photoluminescence (PL), and Van der Pauw methods. The Ge ion-implantation (net concentration: 2.6 × 1020 cm-3) into ZnO is performed using a multiple-step energy. The high resistivity of ?103 ? cm in un-implanted samples remarkably decreased to ?10-2 ? cm after implanting Ge-ion and annealing subsequently. NRA measurements of as-implanted and annealed samples suggest the existence of the lattice displacement of O atoms acting as acceptor defects. As O related defects still remain after annealing, these defects are not attributed to the origin of the low resistivity in 800 and 1000 °C annealed ZnO.

Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

2014-08-01

175

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

SciTech Connect

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

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

2008-02-01

176

I Lost My Tooth!  

ERIC Educational Resources Information Center

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

Boehm, Diann

1997-01-01

177

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

PubMed

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

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

2013-01-01

178

Current trends in dental implants  

PubMed Central

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

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

2014-01-01

179

Effects of silicon surface amorphization on single carbon atom deposition/implantation  

NASA Astrophysics Data System (ADS)

The deposition of carbon on an amorphous silicon surface is modelled by using molecular dynamics simulations combined with a third generation force field that includes bond breaking and formation. The results are compared to carbon deposition on a crystalline (1 0 0) surface in order to investigate the effects of the substrate amorphization. This amorphization may lead to a deeper or a shallower implantation of the carbon atom, depending on its initial trajectory. If the trajectory leads to a channelling effect in the crystalline surface, the implantation is shallower in the amorphous substrate and if not, the implantation is deeper in the amorphous substrate than in the crystalline one. It is also observed that under-coordinated silicon atoms at the amorphous surface tend to increase the sticking coefficient. This holds particularly true for conditions where a relatively high backscattering yield of the carbon atom on the crystalline surface is observed, as the under-coordinated silicon atoms play the role of traps, catching more carbon atoms at the surface than the silicon surface atoms in the crystalline model.

Briquet, Ludovic G. V.; Philipp, Patrick; Wirtz, Tom

2013-05-01

180

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

PubMed Central

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

Nimcenko, Tatjana; Omerca, Grazvydas; Varinauskas, Vaidas; Bramanti, Ennio; Signorino, Fabrizio; Cicciu, Marco

2013-01-01

181

Three tooth kinematic coupling  

DOEpatents

A three tooth kinematic coupling based on having three theoretical line contacts formed by mating teeth rather than six theoretical point contacts. The geometry requires one coupling half to have curved teeth and the other coupling half to have flat teeth. Each coupling half has a relieved center portion which does not effect the kinematics, but in the limit as the face width approaches zero, three line contacts become six point contacts. As a result of having line contact, a three tooth coupling has greater load capacity and stiffness. The kinematic coupling has application for use in precision fixturing for tools or workpieces, and as a registration device for a work or tool changer or for optics in various products.

Hale, Layton C. (Livermore, CA)

2000-01-01

182

Tooth whitening in children.  

PubMed

Although there are several case reports of vital tooth bleaching in children, there is limited clinical trial evidence of the safety or efficacy of this practice. Accordingly, a new clinical trial was conducted to evaluate the effects of 2 different bleaching systems, a 6.5% hydrogen peroxide strip system and a 10% carbamide peroxide tray system, in a population of preteens and teens. A total of 106 volunteers, aged 11 to 18 years, took part in this 8-week study. Patients were randomized by a ratio of 2:1 to the strip or tray groups, with each group treating the maxillary arch first and then the mandibular arch for 4 consecutive weeks each. Individuals assigned to the strip group used the system twice daily for 30 minutes (a total of 56 contact hours over the 8-week study). Those assigned to the tray group used that system overnight (approximately 448 contact hours). Digital images were obtained at baseline and after every 2-week treatment period. Average tooth color was determined in L*, a*, b* color space, where L* indicated lightness, a* indicated red-green, and b* indicated yellow-blue. Both systems significantly whitened teeth (P < 0.0001). While there were no significant differences between groups with respect to the primary whitening response (delta b*) on the maxillary teeth, 4 weeks of overnight treatment with the 10% carbamide peroxide tray (approximately 224 contact hours) yielded statistically significant whitening (P < 0.05) on the mandibular teeth compared with the 6.5% hydrogen peroxide strip used for 28 hours. Both tooth-whitening systems had similar sensitivity/irritation reported after instructed use. This research demonstrates that tooth whitening in teens may be safely accomplished using either the short-contact-time hydrogen peroxide bleaching strips or the overnight carbamide peroxide tray systems tested in this study. PMID:11913290

Donly, Kevin J; Donly, Adriana Segura; Baharloo, Laila; Rojas-Candelas, Edith; Garcia-Godoy, Franklin; Zhou, Xiaojie; Gerlach, Robert W

2002-01-01

183

Pulsed laser deposition of bioceramic thin films from human tooth  

NASA Astrophysics Data System (ADS)

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.

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

184

Infective complications after transcatheter aortic valve implantation: results from a single centre.  

PubMed

After its first introduction in 2002, transcatheter aortic valve implantation (TAVI) has continuously gained more foothold for the treatment of severe aortic stenosis and is nowadays a viable treatment option for inoperable patients or patients at high risk for conventional surgical aortic valve replacement. Although ideally carried out in a so-called hybrid room, incorporating both the strict hygiene and advanced life support possibilities of the operating theatre and the imaging and percutaneous arsenal of the catheterisation suite, in most centres TAVI is at present performed in the catheterisation laboratory. This may raise concern about an increased risk of infection, since there the criteria that are applied regarding disinfection and sterilisation are not as stringent as those of the operating theatre. Therefore, we retrospectively assessed the number of infective complications in patients undergoing TAVI in the catheterisation lab of our institution. Eleven out of 73 patients developed a postprocedural infection, one of which could be attributed to the procedure itself, being superinfection of a surgical groin cut-down. Our conclusion is that percutaneous aortic valve implantation in a catheterisation laboratory is not associated with an increased risk of infective complications. PMID:22890618

Onsea, K; Agostoni, P; Voskuil, M; Samim, M; Stella, P R

2012-09-01

185

Comparison of single-standing or connected implants on stress distribution in bone of mandibular overdentures: a two-dimensional finite element analysis.  

PubMed

This study aimed to compare the influence of single-standing or connected implants on stress distribution in bone of mandibular overdentures by means of two-dimensional finite element analysis. Two finite element models were designed using software (ANSYS) for 2 situations: bar-clip (BC) group-model of an edentulous mandible supporting an overdenture over 2 connected implants with BC system, and o'ring (OR) group-model of an edentulous mandible supporting an overdenture over 2 single-standing implants with OR abutments. Axial loads (100 N) were applied on either central (L1) or lateral (L2) regions of the models. Stress distribution was concentrated mostly in the cortical bone surrounding the implants. When comparing the groups, BC (L1, 52.0 MPa and L2, 74.2 MPa) showed lower first principal stress values on supporting tissue than OR (L1, 78.4 MPa and L2, 76.7 MPa). Connected implants with BC attachment were more favorable on stress distribution over peri-implant-supporting tissue for both loading conditions. PMID:20485031

Tabata, Lucas Fernando; Assunção, Wirley Gonçalves; Barão, Valentim Adelino Ricardo; Gomes, Erica Alves; Delben, Juliana Aparecida; de Sousa, Edson Antônio Capello; Rocha, Eduardo Passos

2010-05-01

186

Charge density wave transport in heterogeneously doped NbSe3 single crystals by masked ion (B^+, Li^+) implantation  

NASA Astrophysics Data System (ADS)

Charge-density wave is competing electron spectrum instability of superconductivity (SC). CDW transport vs. SC with boundary between CDWs and SC are well known examples of correlated transport of macroscopic numbers of electrons.CDW superconductors include layered dichalcogenides, NbSe3. On selective area medium energy ion (B^+, Li^+) implantation was used to create irradiated/unmodified/irradiated CDW heterostructures with well-defined interfaces on single NbSe3 crystal. The effects of impurities go beyond simply increasing CDW pinning (J.P.McCarten.et.al J.Phys.IV France 9,1999).The dV/dI vs. bias at several temperatures, and zero-bias resistance vs. temperature, where two voltage contacts straddle the interface (near the boundary between B^+/ Li^+-implanted and unimplanted regions) are well studied. Injected charge B^+/Li^+ is a non-isoelectronic impurity. The results of ongoing investigations of similar studies of boron- and lithium-doped NbSe3 will be discussed.

Sasmal, Kalyan; Wijesinghe, Asanga; Wijesundera, Dharshana; Tang, Zhongjia; Guloy, Arnold; Chu, Wei-Kan; Miller, John H.

2013-03-01

187

Management of peri-implantitis  

PubMed Central

Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis.

Prathapachandran, Jayachandran; Suresh, Neethu

2012-01-01

188

About Kids' Teeth: Prevent Kids' Tooth Decay  

MedlinePLUS

... Decay Thumb sucking Prevent Decay Nutrition Prevent Kids’ Tooth Decay You can prevent tooth decay for your kids by lowering the risk of your baby getting the bacteria that cause tooth decay. Make sure you take good care of your ...

189

21 CFR 872.3920 - Porcelain tooth.  

Code of Federal Regulations, 2010 CFR

...2012-04-01 2012-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food and...Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of...

2012-04-01

190

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

SciTech Connect

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

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

2010-11-15

191

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

Microsoft Academic Search

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

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

2000-01-01

192

Treatment of Necrotic Calcified Tooth Using Intentional Replantation Procedure  

PubMed Central

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

Arvin, Armita; Darvish, Alireza; Aflaki, Sareh

2014-01-01

193

Treatment of necrotic calcified tooth using intentional replantation procedure.  

PubMed

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

Moradi Majd, Nima; Arvin, Armita; Darvish, Alireza; Aflaki, Sareh; Homayouni, Hamed

2014-01-01

194

Tooth formation - delayed or absent  

MedlinePLUS

Delayed or absent tooth formation; Teeth - delayed or absent formation ... The timing of the first appearance of teeth varies. Most infants get their first tooth between 6 and 9 months, although earlier or later eruption may be normal. In some cases, ...

195

Attachment of anterior tooth fragments  

Microsoft Academic Search

This investigation examined the relationships of tooth preparation and resin material types in repair of fractured anterior teeth by reattachment of fractured tooth fragments. A total of 44 extracted maxillary central incisors were tested. Statistical analysis revealed that no mechanical preparation of the enamel was as retentive as a 45°-circumferential bevel (p K.01). In addition, light-cured resin proved to be

Jeffrey A. Dean; Marjorie L. Swartz; David R. Avery

1986-01-01

196

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

PubMed Central

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

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

2013-01-01

197

Bilateral fusion of mandibular second premolar and supernumerary tooth: A rare case report.  

PubMed

Fusion is the union of two normally separated tooth germs resulting in the formation of a single large tooth. The prevalence of this anomaly is less than 1% and most common in the primary dentition, in the incisor-canine region. Fusions are almost always unilateral, but few cases of bilateral fusions have been reported. The purpose of this article is to report a rare case of bilateral fusion of mandibular second premolar with supernumerary tooth. PMID:22434949

Muthukumar, R Sathish; Arunkumar, Sandhya; Sadasiva, Kadandale

2012-01-01

198

Thermal and ion beam diffusion constants of Sb impurity implanted into <100> Ni single crystal  

NASA Astrophysics Data System (ADS)

In previous investigations (A. Belattar et al., Nucl. Instr. and Meth. B 88 (1994) 394; B 93 (1994) 261) the annealing of the surface amorphous layer produced in <100> Ni crystal by implantation of 40 keV Sb 2+ to a fluence of 10 17 ions cm -2 was observed to occur in two distinct stages irrespective of whether the anneal process was due to an isochronal anneal in the temperature range 250 to 1100°C or whether the process involved the high energy irradiation with 1.5 MeV Ar or Xe ions at a constant temperature of 350°C. In this study the diffusion of the Sb was monitored by observing the Sb profile using the Rutherford backscattering technique. A computer fitting procedure was adopted to quantitatively determine the standard deviation of the width of the Sb profile (?), the results of which showed that this is a good parameter for monitoring the various diffusion processes. The results of the analysis show that in the case of the first anneal stage the diffusion is relatively slow, but that there is evidence that some form of segregation of the Sb impurity occurs; this is most pronounced during a prolonged isothermal anneal carried out at 350°C. The second rapid anneal stage is accompanied by an equally rapid diffusion of the Sb impurities. In the case of the isochronal anneal, the activation energy for the diffusion process was measured to be 2.0 eV, which is not incompatible with a vacancy diffusion mechanism. In the case of the ion beam annealing processes, the monitoring of ? clearly showed a considerable enhancement of the main diffusion process of the Sb impurity which is directly related to the vacancies produced by the incident high energy irradiation.

Belattar, A.; Stephens, G. A.; Cardwell, P. D.

199

Early cleavage: an additional predictor of high implantation rate following elective single embryo transfer  

Microsoft Academic Search

The value of early cleavage (EC) assessment is still being debated. The aim of this prospective study was to examine the predictive value of EC assessment performed exactly 26 h after insemination by IVF or intracytoplasmic sperm injection (ICSI) in a programme of elective single embryo transfer (SET) performed at day 2. If day 2 scoring demonstrated several embryos with

C Giorgetti; E Hans; P Terriou; J Salzmann; B Barry; V Chabert-Orsini; JM Chinchole; JP Franquebalme; E Glowaczower; M-C Sitri; M-C Thibault; R Roulier

2007-01-01

200

A conservative aesthetic solution for a single anterior edentulous space: case report and one-year follow-up.  

PubMed

Conservative solutions for the restoration of a single edentulous space in the anterior maxilla present an aesthetic challenge to the clinician. Treatment options for tooth replacement include implant placement, a classical fixed partial denture, or a resin-bonded appliance with a metal substructure or fiber-reinforced resin. The resin-bonded Encore Bridge (daVinci Studios, Woodland Hills, CA) offers a restorative solution that is conservative and aesthetic when compared to the required full-tooth preparation in a conventional three-unit fixed partial denture. This case report addresses the indications, preparation guidelines, and restorative procedures for an Encore Bridge. PMID:11799795

Leal, F R; Cobb, D S; Denehy, G E; Margeas, R C

2001-10-01

201

Ultrastructural localization of laminin-5 ( ? 2 chain) in the rat peri-implant oral mucosa around a titanium-dental implant by immuno-electron microscopy  

Microsoft Academic Search

Laminin-5 (Ln-5) is an important molecule associated with epithelial cell adhesion and migration. In the gingiva around the tooth, Ln-5 localizes within basement membranes between the junctional epithelium (JE) and the tooth or connective tissue. Recently, we reported that in the oral mucosa around a dental implant, Ln-5 is expressed within the basement membranes at the implant-peri-implant epithelium (PIE) interface,

Ikiru Atsuta; Takayoshi Yamaza; Masao Yoshinari; Tetsuya Goto; Mizuho A. Kido; Tadayoshi Kagiya; Satoya Mino; Masaki Shimono; Teruo Tanaka

2005-01-01

202

Partial tooth gear bearings  

NASA Technical Reports Server (NTRS)

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

Vranish, John M. (Inventor)

2010-01-01

203

Cochlear Implants  

MedlinePLUS

... treated only with a cochlear implant. How do cochlear implants work? Cochlear implants bypass damaged hair cells and ... brain, where it is interpreted as meaningful sound. Cochlear implant benefits Cochlear implants are designed only for individuals ...

204

Evaluation of Carbon Interstitial in C-ion Implanted ZnO Bulk Single Crystals by a Nuclear Reaction Analysis Study: An Origin of Low Resistivity  

SciTech Connect

Nuclear reaction analysis (NRA) of carbon-implanted ZnO bulk single crystals (carbon concentration: 1.5x10{sup 20} cm{sup -3}), in conjunction with the channeling technique, using the {sup 12}C(d,p){sup 13}C and {sup 16}O(d,p){sup 17}O reactions shows the presence of the interstitial carbon (C{sub i}) and the occupancy of substitute sites of oxygen atoms. These results suggest that the variation in resistivity from the order of 10{sup 4} {Omega}cm(for un-implanted samples) to that of 10 {Omega}cm (for as-implanted ones) is attributed to the C{sub i} and/or its complex defects, which would act as a shallow donor in ZnO.

Izawa, Y.; Matsumoto, K.; Oga, T.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Department of Arts and Sciences, Osaka Kyoiku University, Kashiwara, Osaka 582-8582 (Japan); Kinomura, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

2011-12-23

205

Single-action implantation of a 3-piece acrylic intraocular lens with an injector.  

PubMed

We report a method to insert a 3-piece AcrySof MA30BA acrylic foldable intraocular lens (IOL) (Alcon) in a single action using a Monarch II (Alcon) injector. The technique was used in 134 eyes. The incision widths ranged from 3.00 to 3.75 mm. The IOLs were successfully inserted in the capsular bag. Complications included cracks in the IOL optic in 3 eyes (3%), haptic damage in 3 eyes (3%), and inadequate self-sealing of the incision in 18 eyes (13%). PMID:12648632

Takeshita, Tetsuji; Yamada, Kazuhiro; Tanihara, Hidenobu

2003-02-01

206

Role of multiple cusps in tooth fracture.  

PubMed

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

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

2014-07-01

207

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

PubMed

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

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

2014-04-01

208

Passivity versus unilateral angular misfit: evaluation of stress distribution on implant-supported single crowns: three-dimensional finite element analysis.  

PubMed

The aim of this study was to evaluate the effect of unilateral angular misfit of 100 ?m on stress distribution of implant-supported single crowns with ceramic veneering and gold framework by three-dimensional finite element analysis. Two three-dimensional models representing a maxillary section of premolar region were constructed: group 1 (control)-crown completely adapted to the implant and group 2-crown with unilateral angular misfit of 100 ?m. A vertical force of 100 N was applied on 2 centric points of the crown. The von Mises stress was used as an analysis criterion. The stress values and distribution in the main maps (204.4 MPa for group 1 and 205.0 MPa for group 2) and in the other structures (aesthetic veneering, framework, retention screw, implant, and bone tissue) were similar for both groups. The highest stress values were observed between the first and second threads of the retention screw. Considering the bone tissue, the highest stress values were exhibited in the peri-implant cortical bone. The unilateral angular misfit of 100 ?m did not influence the stress distribution on the implant-supported prosthesis under static loading. PMID:21119400

Gomes, Erica Alves; Assunção, Wirley Gonçalves; Barão, Valentim Adelino Ricardo; Delben, Juliana Aparecida; Rocha, Eduardo Passos; de Sousa, Edson Antonio Capello

2010-11-01

209

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

210

Reflex responses of motor units in human masseter muscle to mechanical stimulation of a tooth  

Microsoft Academic Search

The reflex responses evoked by controlled mechanical stimulation of an upper central incisor tooth in single motor units in the human masseter muscle were examined. The stimuli were (brisk) taps and (slow) pushes of about 2 N peak force, applied orthogonally to the labial surface of the ipsilateral upper central incisor tooth. The reflex responses of the motor units were

Kemal S. Türker; Pål Brodin; Timothy S. Miles

1994-01-01

211

The Early Years: Tooth Time  

NSDL National Science Digital Library

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

Ashbrook, Peggy

2006-03-01

212

The Human Sweet Tooth  

PubMed Central

Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries.

Reed, Danielle R; McDaniel, Amanda H

2006-01-01

213

The human sweet tooth.  

PubMed

Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries. PMID:16934118

Reed, Danielle R; McDaniel, Amanda H

2006-01-01

214

Coarsening model of cavity nucleation and thin film delamination from single-crystal BaTiO3 with proton implantation  

NASA Astrophysics Data System (ADS)

The layer splitting mechanism of a proton implanted single crystal ferroelectric BaTiO3 thin film layer from its bulk BaTiO3 substrate has been investigated. The single crystal BaTiO3 thin film layer splits as the hydrogen gas diffuses and the internal cavity pressure increases. Ripening mechanism driven by the pressurized hydrogen in the implantation-induced damage zone makes coarsening of the cavities and causes the delamination of the thin layer during the annealing. A unique criterion relation of blister nucleation and evolution has been derived and a simplified debonding criterion is proposed in terms of dimensionless parameters based on the force equilibrium condition. A numerical simulation of two-bubble evolution and delamination of thin film is performed using a finite element method.

Hong, Jung-Wuk; Pyeon, Jae-Ho; Tedesco, Joseph W.; Park, Young-Bae

2007-06-01

215

Ovarian Function During the Use of a Single Contraceptive Implant: Implanon Compared with Norplant 1 1 Supported by NV Organon, Oss, The Netherlands  

Microsoft Academic Search

Objective: To study the mechanism of action of Implanon, a single-rod contraceptive implant containing etonogestrel, in healthy women during 3 years.Design: Prospective, randomized comparison with Norplant. The study was conducted for 2 years in Sweden but was extended to 3 years in Finland.Setting: Two outpatient clinics.Patient(s): Thirty-two healthy women who were between 18 and 40 years of age with normal

Leo Mäkäräinen; Agaath van Beek; Leena Tuomivaara; Bo Asplund; Herjan Coelingh Bennink

1998-01-01

216

Annealing-environment effects on the properties of CoPt nanoparticles formed in single-crystal Al2O3 by ion implantation  

Microsoft Academic Search

The ion implantation of nearly equal doses of Co and Pt into a single-crystal Al2O3 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%H2 gives rise to ferromagnetic, chemically ordered CoPt nanoparticles with the L10 structure and a magnetic coercivity that can

Clark W White; Stephen P Withrow; John D Budai; Darrell Keith Thomas; J. M. Williams; A. Meldrum; K. D. Sorge; James R Thompson; Gary Webb Ownby; J. F. Wendelken; Lynn A Boatner

2005-01-01

217

Reconstruction of extraordinary refractive index profiles of optical planar waveguides with single or double modes fabricated by O 2+ ion implantation into lithium niobate  

Microsoft Academic Search

A method named intensity calculation method (ICM), which is based on beam propagation method (BPM) and image processing, was carried out to reconstruct the extraordinary refractive index profile (RIP) of single-mode planar waveguide in lithium niobate (LiNbO3), which was fabricated by multi-energy megaelectron-volt (MeV) O2+ ion implantation. In addition, it has been proved reasonable that the alternation of extraordinary refractive

Xiangzhi Liu; Fei Lu; Feng Chen; Yang Tan; Ruifeng Zhang; Hanping Liu; Lei Wang; Liangling Wang

2008-01-01

218

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

Microsoft Academic Search

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

Morio Sato; Takashi Mori; Shintaro Shirai; Kazushi Kishi; Takeshi Inagaki; Isao Hara

2008-01-01

219

Ion Implantation in Perovskite Type Ferroelectrics.  

National Technical Information Service (NTIS)

The object of this work was to study ion implantation in perovskite ferroelectrics and to investigate the conductive behavior of implanted layers. Implantation experiments were carried out on strontium titanate, barium titanate (single crystal and ceramic...

R. Gerson

1979-01-01

220

Interproximal Papillae Reconstruction around Implant Using Subepithelial Connective Tissue Graft in Maxillary Anterior Region: A Case Series  

PubMed Central

ABSTRACT Objectives The present study was undertaken to evaluate the effectiveness of interproximal papillae reconstruction around early loaded single implant using subepithelial connective tissue graft in maxillary anterior region. Material and Methods Ten systemically healthy patients (mean age = 29.3 [SD 7.9] years) in need of dental implants in maxillary anterior region were included in the study. Interproximal papillae reconstruction around single implant using subepithelial connective tissue graft was applied. The donor palatal tissue was harvested by a "trap door approach". Subepithelial connective tissue graft was inserted in the pouch created on mesial and distal site of implant. Clinical and radiographic parameters were recorded around the each implant, including papillary height and papillary gingival contour, at baseline, 3 and 6 months after operation. Results The mesial papilla height was increased by 1.9 (SD 0.87) mm, P = 0.005 at 3 month and maintained at 1.5 (SD 0.97) mm, P = 0.007 at 6 months. The distal papilla height was increased by 2 (SD 0.66) mm, P = 0.004 at 3 month and maintained at 1.2 (SD 0.78) mm, P = 0.010 at 6 months. Assessment of papilla contour index showed 90% aesthetic success both for mesial and distal papilla at 6 months. Conclusions It can be concluded that subepithelial connective tissue graft may be used to successfully augment the gingival papillae adjacent to single tooth implant restoration.

Gupta, Satish; Williams, Cecil

2012-01-01

221

Treatment of protruding osseo integrated dental implant  

PubMed Central

Titanium dental implants have been used in the treatment of partial or complete edentulism. The height and width of the residual alveolus and surrounding anatomical structures can determine the proper position and path of insertion of dental implants. The following case report describes the treatment of a malpositioned osseo integrated dental implant with an apex perforating the buccal cortex of alveolar bone. A 61-year-old male was referred by his local dentist for the chief complaint of a swelling at site of tooth 14 where an implant was present. Intraoral clinical examination revealed an implant supported porcelain fused to metal crown replacing the maxillary right first premolar. A peri-apical radiograph of the implant revealed no signs of peri-implant bone loss or radiolucency. Surgical exploration and modification of the protruding implant. The area healed uneventfully without the need of explantation of the implant in site of tooth 14. We felt that the conservative treatment provided was prudent and treatment of choice and anticipate that the implant will most likely continue to function for a lifetime.

Buddula, Aravind; Sheridan, Phillip; Balshe, Ayman

2010-01-01

222

Clinical measurement of tooth wear: Tooth wear indices  

PubMed Central

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

Lopez-Frias, Francisco J.; Castellanos-Cosano, Lizett; Martin-Gonzalez, Jenifer; Llamas-Carreras, Jose M.

2012-01-01

223

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

Microsoft Academic Search

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

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

2007-01-01

224

Magnitude of orthodontic forces and rate of bodily tooth movement. An experimental study  

Microsoft Academic Search

The relationship between the magnitude of a constant continuous orthodontic force and rate of bodily tooth movement was studied. In 25 young adult male beagle dogs, lower third premolars were extracted and bone markers were implanted in the mandible. Sixteen weeks later, an orthodontic appliance was placed, and elastics exerting 50, 100, or 200 gm were attached to the lower

Jack J. G. M. Pilon; Anne M. Kuijpers-Jagtman; Jaap C. Maltha

1996-01-01

225

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

PubMed

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

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

2014-06-01

226

X-ray microbeam probing of elastic strains in patterned He+ implanted single-crystal LiNbO3  

Microsoft Academic Search

X-ray microprobing is used to investigate buried elastic strain resulting from deep He+ implantantion in LiNbO3. The implantation regions are defined lithographically and strain fields mapped with spatial- and energy-resolved x-ray microdiffraction to characterize the resulting structures. The structurally modified regions are found to retain their lateral lithographic definition, with the buried implantation being in strong compression.

Djordje Djukic; Ryan M. Roth; R. M. Osgood; Kenneth Evans-Lutterodt; Hassaram Bakhru; Sasha Bakhru; David Welch

2007-01-01

227

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

PubMed Central

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

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

2012-01-01

228

Clinical Management of Implant Prostheses in Patients with Bruxism  

PubMed Central

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

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

2012-01-01

229

Clinical management of implant prostheses in patients with bruxism.  

PubMed

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

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

2012-01-01

230

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

PubMed Central

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

Kajale, Aniruddha M.; Mehta, Dhoom S.

2014-01-01

231

Narrow diameter implant in posterior region  

PubMed Central

Dental implants placement can sometimes be limited due to physical conditions, wherein the horizontal space is limited by adjacent teeth and roots or situations in which there is narrow alveolar ridge, By using a narrow diameter implant (NDI), the need for bone augmentation can be avoided. In situations where there is limited horizontal space, a NDI may be the only option to replace a missing tooth.

Mohamed, Jumshad B.; Alam, Md. Nazish; Salman, Arif; Chandrasekaran, S. C.

2012-01-01

232

Safety controversies in tooth bleaching.  

PubMed

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

Li, Yiming

2011-04-01

233

Reconstruction of extraordinary refractive index profiles of optical planar waveguides with single or double modes fabricated by O 2+ ion implantation into lithium niobate  

NASA Astrophysics Data System (ADS)

A method named intensity calculation method (ICM), which is based on beam propagation method (BPM) and image processing, was carried out to reconstruct the extraordinary refractive index profile (RIP) of single-mode planar waveguide in lithium niobate (LiNbO 3), which was fabricated by multi-energy megaelectron-volt (MeV) O 2+ ion implantation. In addition, it has been proved reasonable that the alternation of extraordinary refractive index induced by ion implantation into LiNbO 3 is mainly due to the degradation of polarization and reduction of material physical density. As a result, the possible extraordinary RIP of the double-mode planar waveguide could be reconstructed using BPM according to such a hypothesis and the calculated guiding mode values. The end-fire coupling and m-line arrangements were carried out to obtain the near-field modal patterns and dark-mode spectra of waveguides, respectively.

Liu, Xiangzhi; Lu, Fei; Chen, Feng; Tan, Yang; Zhang, Ruifeng; Liu, Hanping; Wang, Lei; Wang, Liangling

2008-03-01

234

Octacalcium phosphate (OCP) collagen composites enhance bone healing in a dog tooth extraction socket model.  

PubMed

The authors have reported that a scaffold constructed of synthetic octacalcium phosphate (OCP) and porcine atelocollagen sponge (OCP/Col) enhanced bone regeneration more than sintered beta-tricalcium phosphate collagen composite or sintered hydroxyapatite collagen composite with a rat calvarial defect model. To aim for clinical application, the present study investigated whether OCP/Col would enhance bone healing in a dog tooth extraction socket model. Six adult, male, beagle dogs were used. The tooth extraction socket model was made by extracting bilateral third maxillary incisors and the subsequent removal of buccal bone. Disks of OCP/Col were implanted into one side of the model and the other side was untreated. The specimens were fixed 1 or 3 months after implantation. In radiographic analysis, the OCP/Col-treated group showed a wider range of radiopacity than the untreated control. Histologically, the OCP/Col-treated group showed more abundant newly formed bone than untreated control, and the implanted OCP was gradually resorbed. In morphometrical analysis, enlargement of the buccal alveolus in the OCP/Col group was significantly greater than in the untreated control. This study showed that implanted OCP/Col would be replaced by newly formed bone and OCP/Col implantation would enhance bone healing in a tooth socket model. PMID:20060266

Iibuchi, S; Matsui, K; Kawai, T; Sasaki, K; Suzuki, O; Kamakura, S; Echigo, S

2010-02-01

235

Mandibular lateral incisor with four root canals: A unique case of double tooth diagnosed using multidetector computed tomography  

PubMed Central

Double tooth is a dental anomaly consequent to fusion of two or more teeth or gemination of a single tooth. This report describes a unique case of double tooth in relation to a mandibular lateral incisor exhibiting the presence of four root canals. The role of conventional radiography and advanced three-dimensional imaging techniques in the better assessment of complex root canal systems and their aid in endodontic management has also been highlighted.

Gupta, Sunil Kumar; Acharya, Shashi Rashmi; Ather, Amber

2013-01-01

236

Optimum tooth profile design for hypoid gear  

Microsoft Academic Search

The profile modification of tooth surface is one of the best methods of decreasing the transmission error of hypoid gears, and is not subject to the effect of productive dispersion. In the past, it was very difficult to optimize the profile modification of the tooth surface while observing and developing the tooth bearing. Accordingly a technique to analyze the relation

Yoshikatsu Shibata; Norihiko Kondou; Toshinari Ito

1997-01-01

237

Tooth Avulsion in the School Setting  

ERIC Educational Resources Information Center

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

Krause-Parello, Cheryl A.

2005-01-01

238

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

PubMed Central

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

2014-01-01

239

Immediate placement of implant in fresh extraction socket with early loading  

PubMed Central

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

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

2012-01-01

240

Tooth replacement in Gadus callarias  

Microsoft Academic Search

Upper and lower jaws of large and small specimens of the cod Gadus callarias were stained in toto by Alizarin and cleared in plastic to chart the distribution of ankylosed teeth and mineralized tooth germs. Other jaws of the same species were decalcified and transversely sectioned in series to reconstruct the dentition graphically. It was found that the dentition in

N. Holmbakken; G. Fosse

1973-01-01

241

Tooth Loss in Periodontal Patients  

Microsoft Academic Search

Objective: To compare tooth loss between patients who received surgical therapy for chronic periodontitis and those who received nonsurgical therapy alone. Methods: A retrospective chart study was conducted at Dalhousie University. All patients who had periodontal treat- ment and were active cases for at least 10 years were included (n = 335). The sample consisted of 120 males (35.8%) and

Debora C. Matthews; Craig G. Smith; Stacy L. Hanscom

242

Dental implant changes following incineration.  

PubMed

Non-visual identification of victims utilizes DNA, fingerprint and dental comparison as primary scientific identifiers. In incidents where a victim has been incinerated, there may be loss of fingerprint detail and denaturing of DNA. Although extremely durable, tooth loss will also occur with extreme temperatures and the characteristics of recovered dental implants, if any, may be the only physical identifying data available. Currently, there are no experimental investigations to determine what changes occur to dental implants following high temperature exposure. A selection of dental implants was radiographed, utilizing purpose built apparatus to allow standard methodology. They were then heated in an INFI-TROL™ kiln to a maximum temperature of 1125°C and the radiographic procedure repeated. Image subtraction evaluation of the radiographs was recorded using Adobe(®) Photoshop(®). Both commercially pure titanium and titanium alloy dental implants survived the incineration and there was oxidation of the surface leading to minor alteration of the image. There was, however, no detectable sagging of the implants. The results of this research suggest that dental implants are still recognizable following incineration. In scenarios commonly seen by forensic odontologists, heat will destroy both teeth and conventional dental restorative materials. Implants, however, will resist these conditions and will also retain the features necessary to identify the type of implant. PMID:20880643

Berketa, J; James, H; Marino, V

2011-04-15

243

Sequential provisional implant prosthodontics therapy.  

PubMed

The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results. PMID:23220306

Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

2012-01-01

244

Dental follicle cells and treated dentin matrix scaffold for tissue engineering the tooth root.  

PubMed

Tissue engineering strategies to reconstruct tooth roots are an effective therapy for the treatment of tooth loss. However, strategies to successfully regenerate tooth roots have not been developed and optimized. In the present study, rat dental follicle stem cells (DFCs) were characterized, followed by a thorough investigation of tooth roots regeneration for a combination of DFCs seeding cells, treated dentin matrix (TDM) scaffolds, and an inductive alveolar fossa microenvironment. Eighteen clones derived from single DFCs were harvested; however, only three clones were amplified successfully more than five passages and 90-95 days in culture. Following 270 days or 30 passages, the heterogeneous DFCs showed suitable characteristics for seeding cells to regenerate tooth roots. However, various features, such as variable proliferation rates, differentiation characteristics, apoptosis rates, and total lifespan were observed in DFCs and the three clones. Importantly, upon transplantation of DFCs combined with TDM for four weeks, root-like tissues stained positive for markers of dental pulp and periodontal tissues were regenerated in the alveolar fossa, but not in the skull and omental pockets. These results indicate that tooth roots were successfully regenerated and suggest that the combination of DFCs with TDM in the alveolar fossa is a feasible strategy for tooth roots regeneration. This strategy could be a promising approach for the treatment of clinical tooth loss and provides a perspective with potential applications to regeneration of other tissues and organs. PMID:22088889

Guo, Weihua; Gong, Kun; Shi, Haigang; Zhu, Guoxiong; He, Yong; Ding, Bofu; Wen, Lingying; Jin, Yan

2012-02-01

245

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

PubMed

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

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

2012-07-01

246

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

PubMed

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

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

2014-01-01

247

Importance of a distal proximal contact on load transfer by implant-supported single adjacent crowns in posterior region of the mandible: a photoelastic study  

PubMed Central

Objective This study aimed to evaluate the importance of a distal proximal contact on the load transfer to the posterior region of the mandible by non-splinted adjacent implant-supported crowns using photoelastic stress analysis. Material and Methods A rectangular model (68x30x15 mm) was made of polymethylmethacrylate resin to simulate half of the mandibular arch. One model was completed with resin replicas representing the first premolar and second molar and with two 3.75 mm dia.x11 mm internal hexagon threaded implants replacing the second premolar and first molar. The other model was manufactured in the same way but without the second molar. Both models were duplicated using photoelastic resin. The roots of the teeth replicas were covered with a layer of polyether impression material to simulate the periodontal ligament. Two different vertical loads were applied to the crowns as follows: 1 - single static point load alternately applied to the crowns replacing the second premolar and first molar (50 N); 2 - simultaneous static point loads applied to both of the crowns replacing the second premolar and first molar (100 N). The resulting isochromatic fringe pattern in the photoelastic model was monitored and photographed. Results All loading conditions studied showed that the presence of the second molar has changed the load transmission and the pattern of stresses. Conclusion Results showed that the presence of a second molar proximal contact can help minimize the stresses around the implants.

de AGUIAR JUNIOR, Fabio Afranio; TIOSSI, Rodrigo; MACEDO, Ana Paula; de MATTOS, Maria da Gloria Chiarello; RIBEIRO, Ricardo Faria; RODRIGUES, Renata Cristina Silveira

2013-01-01

248

Alveolar ridge resorption after tooth extraction: A consequence of a fundamental principle of bone physiology  

PubMed Central

It is well established that tooth extraction is followed by a reduction of the buccolingual as well as the apicocoronal dimension of the alveolar ridge. Different measures have been taken to avoid this bone modelling process, such as immediate implant placement and bone grafting, but in most cases with disappointing results. One fundamental principle of bone physiology is the adaptation of bone mass and bone structure to the levels and frequencies of strain. In the present article, it is shown that the reduction of the alveolar ridge dimensions after tooth extraction is a natural consequence of this physiological principle.

Halldin, Anders

2012-01-01

249

In vitro comparison of resistance to implant failure in unstable trochanteric fractures fixed with intramedullary single screw versus double screw device  

PubMed Central

Background: The purpose of this study was to compare the resistance of intramedullary single screw device (Gamma nail) and double screw device proximal femoral nail (PFN) in unstable trochanteric fractures in terms of the number of cycles sustained, subsidence and implant failure in an axial loading test in cadaveric femora. Materials and Methods: The study was conducted on 18 dry cadaveric femoral specimens, 9 of these were implanted with a Gamma nail and 9 with PFN. There was no significant difference found in average dual energy X-ray absorptiometry value between both groups. The construct was made unstable (AO type 31A3.3) by removing a standard sized posteromedial wedge. These were tested on a cyclic physiological loading machine at 1 cycle/s with a load of 200 kg. The test was observed for 50,000 loading cycles or until implant failure, whichever occurred earlier. Peak displacements were measured and analysis was done to determine construct stiffness and gap micromotion in axial loading. Result: It was observed that there was statistically significant difference in terms of displacement at the fracture gap and overall construct stiffness of specimens of both groups. PFN construct group showed a mean subsidence of 1.02 mm and Gamma nail construct group showed mean subsidence of 2.36 mm after cycling. The average stiffness of Gamma nail group was 62.8 ± 8.4 N/mm which was significantly lower than average stiffness of the PFN group (80.4 ± 5.9 N/mm) (P = 0.03). In fatigue testing, 1 out of 9 PFN bone construct failed, while 5 of 9 Gamma nail bone construct failed. Conclusion: When considering micromotion (subsidence) and incidence of implant/screw failure, double screw device (PFN) had statistically significant lower micromotion across the fracture gap with axial compression and lower incidence of implant failure. Hence, double screw device (PFN) construct had higher stability compared to single screw device (GN) in an unstable trochanteric fracture femur model.

Rastogi, Amit; Arun, GR; Singh, Vakil; Singh, Anant; Singh, Ashutosh K; Kumaraswamy, Vinay

2014-01-01

250

Automating Digital Leaf Measurement: The Tooth, the Whole Tooth, and Nothing but the Tooth  

PubMed Central

Many species of plants produce leaves with distinct teeth around their margins. The presence and nature of these teeth can often help botanists to identify species. Moreover, it has long been known that more species native to colder regions have teeth than species native to warmer regions. It has therefore been suggested that fossilized remains of leaves can be used as a proxy for ancient climate reconstruction. Similar studies on living plants can help our understanding of the relationships. The required analysis of leaves typically involves considerable manual effort, which in practice limits the number of leaves that are analyzed, potentially reducing the power of the results. In this work, we describe a novel algorithm to automate the marginal tooth analysis of leaves found in digital images. We demonstrate our methods on a large set of images of whole herbarium specimens collected from Tilia trees (also known as lime, linden or basswood). We chose the genus Tilia as its constituent species have toothed leaves of varied size and shape. In a previous study we extracted leaves automatically from a set of images. Our new algorithm locates teeth on the margins of such leaves and extracts features such as each tooth’s area, perimeter and internal angles, as well as counting them. We evaluate an implementation of our algorithm’s performance against a manually analyzed subset of the images. We found that the algorithm achieves an accuracy of 85% for counting teeth and 75% for estimating tooth area. We also demonstrate that the automatically extracted features are sufficient to identify different species of Tilia using a simple linear discriminant analysis, and that the features relating to teeth are the most useful.

Corney, David P. A.; Tang, H. Lilian; Clark, Jonathan Y.; Hu, Yin; Jin, Jing

2012-01-01

251

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

SciTech Connect

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

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

2006-12-01

252

Anatomically shaped tooth and periodontal regeneration by cell homing.  

PubMed

Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-epsilon-caprolactone and hydroxyapatite with 200-microm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular incisor extraction, whereas a human molar scaffold was implanted ectopically into the dorsum. Stromal-derived factor-1 (SDF1) and bone morphogenetic protein-7 (BMP7) were delivered in scaffold microchannels. After 9 weeks, a putative periodontal ligament and new bone regenerated at the interface of rat incisor scaffold with native alveolar bone. SDF1 and BMP7 delivery not only recruited significantly more endogenous cells, but also elaborated greater angiogenesis than growth-factor-free control scaffolds. Regeneration of tooth-like structures and periodontal integration by cell homing provide an alternative to cell delivery, and may accelerate clinical applications. PMID:20448245

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

2010-08-01

253

Percutaneous implantation of pulmonary valves for treatment of right ventricular outflow tract dysfunction: a single-centre experience  

Microsoft Academic Search

Stenosis and\\/or regurgitation of the right-ventricle-to-pulmonary-artery conduit are common conditions in patients after corrective surgery for congenital heart defects. Percutaneous pulmonary valve implantation was introduced to reduce the number of operations needed during the total lifetime of patients with right-ventricle-to-pulmonary-artery conduits. Between April 2007 and April 2008, six patients with severe stenosis and\\/or regurgitation of the conduit underwent percutaneous pulmonary

Paolo Guccione; M. Giulia Gagliardi; Giulio Calcagni; Alejandro Alvarez; Giacomo Pongiglione

2009-01-01

254

Towards tooth friendly soft drinks.  

PubMed

Most soft drinks contain high concentration of simple carbohydrates and have a pH of 3 or even lower. Therefore, they are harmful for tooth structure. A tooth friendly soft drink (T.F.S.D) should have the following characteristics and elements; fluoride (approximately 1 ppm), casein phosphopeptide-amorphous calcium phosphate (2%), xylitol (4-6g/serving), tea polyphenols (2-4 mg/ml), cranberry extract (250 mg/ml of the flavonoids quercetin and myricetin), sugar free, pH close to 5.5 and super oxygenation (240,000 ppm) vs. carbonation. T.F.S.D can be packaged in a container which gaseous oxygen is dissolved in a liquid in the form of bubbles. However, looking at opportunities for so-called sophisticated soft drinks, T.F.S.D will be an example for a functional and health oriented soft drink. PMID:19570614

Kolahi, Jafar; Fazilati, Mohamad; Kadivar, Mahdi

2009-10-01

255

Molecular Genetics of Supernumerary Tooth Formation  

PubMed Central

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

Wang, Xiu-Ping; Fan, Jiabing

2011-01-01

256

Charcot-Marie-Tooth disease  

Microsoft Academic Search

Opinion statement  The family of hereditary peripheral neuropathies that makes up Charcot-Marie-Tooth disease (CMT) comprises some of the most\\u000a common neuromuscular disorders. Over the past decade, understanding of the molecular basis of CMT has increased enormously.\\u000a In addition, the neurophysiologic deficits and clinical problems associated with CMT are more clearly delineated, and the\\u000a precise genetic cause of many types of CMT

Gregory T. Carter; Michael D. Weiss; Jay J. Han; Phillip F. Chance; John D. England

2008-01-01

257

Tooth Size Variation Related to Age in Amboseli Baboons  

PubMed Central

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

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

2011-01-01

258

Consideration of Moving Tooth Load in Gear Crack Propagation Predictions  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

259

Automating digital leaf measurement: the tooth, the whole tooth, and nothing but the tooth.  

PubMed

Many species of plants produce leaves with distinct teeth around their margins. The presence and nature of these teeth can often help botanists to identify species. Moreover, it has long been known that more species native to colder regions have teeth than species native to warmer regions. It has therefore been suggested that fossilized remains of leaves can be used as a proxy for ancient climate reconstruction. Similar studies on living plants can help our understanding of the relationships. The required analysis of leaves typically involves considerable manual effort, which in practice limits the number of leaves that are analyzed, potentially reducing the power of the results. In this work, we describe a novel algorithm to automate the marginal tooth analysis of leaves found in digital images. We demonstrate our methods on a large set of images of whole herbarium specimens collected from Tilia trees (also known as lime, linden or basswood). We chose the genus Tilia as its constituent species have toothed leaves of varied size and shape. In a previous study we extracted c.1600 leaves automatically from a set of c.1100 images. Our new algorithm locates teeth on the margins of such leaves and extracts features such as each tooth's area, perimeter and internal angles, as well as counting them. We evaluate an implementation of our algorithm's performance against a manually analyzed subset of the images. We found that the algorithm achieves an accuracy of 85% for counting teeth and 75% for estimating tooth area. We also demonstrate that the automatically extracted features are sufficient to identify different species of Tilia using a simple linear discriminant analysis, and that the features relating to teeth are the most useful. PMID:22870286

Corney, David P A; Tang, H Lilian; Clark, Jonathan Y; Hu, Yin; Jin, Jing

2012-01-01

260

A modified transvenous single mechanical dilatation technique to remove a chronically implanted active-fixation coronary sinus pacing lead.  

PubMed

We described a 77-year-old patient, previously implanted with a dual-chamber pacemaker later upgraded to a cardiac resynchronization therapy-defibrillator (CRT-D) device with an active-fixation coronary sinus pacing lead, who underwent a transvenous mechanical extraction procedure for a device-related systemic infection. All leads were removed successfully with a transvenous approach. With regard to the coronary sinus (CS) lead (Attain 4195 StarFix, Medtronic Inc., Minneapolis, MN, USA), manual traction was ineffective and extraction required long and challenging mechanical dilatation up to distal CS using either conventional sheaths or modified CS lead delivery. PMID:20487357

Bongiorni, Maria Grazia; Di Cori, Andrea; Zucchelli, Giulio; Segreti, Luca; De Lucia, Raffaele; Paperini, Luca; Soldati, Ezio

2011-07-01

261

[Experimental substantiation of parameters and strength characteristics of new endodontic-endoosseous implant construction].  

PubMed

Postoperative tooth stump is not able to endure usual functional loads adequately that leads to enhanced resorption of bone tissues surrounding root and loss of the tooth. Based on math computer simulation of mode of deformation of biomechanical model "metal-ceramic construction--endodontic-endoosseous implant (EEI)--stump of operated tooth--bone tissue of the jaw" new domestic EEI parameters were elaborated which improved greatly biomechanical properties of tooth with operated roots. Strength characteristics of new EEI were studied. A set of instruments for EEI was developed. PMID:16247396

Arutiunov, S D; Chumachenko, E N; Gvetadze, R Sh; Zubov, S V; Mokhov, A V

2005-01-01

262

[Mathematical investigations of the functional tooth axis].  

PubMed

The functional tooth axis is--contrary of the anatomical tooth axis--defined as follows: The effect of force in its direction causes a maximum of desmodontal fibres being stressed on drawing. After measure of an upper caninus, an upper and a lower molar mathematical models of the teeth and the desmodont of force are calculated with a computer simulation. A variety of functional tooth axes which are not identical with the anatomical ones, result for each tooth. The possible functional axes yield a variety which signifies the biological tolerance. This tolerance causes that many individual forms of occlusion don't have any pathological effect on the desmodont. PMID:1816808

Reiber, T; Buchmann, F

1991-01-01

263

[Implant placement on restricted mesiodistal space with simulation software and guiding system: a case report].  

PubMed

A surgical guiding system with simulation software has recently been used for safe implant treatment. We report a clinical case in which we successfully used this system for implant treatment of a congenital tooth missing region with severely restricted mesiodistal space. The patient was a 19-year-old female whose mandibular right deciduous canine was wobbling without a successional permanent tooth and who desired implant treatment. CT images showed that this site was narrow buccal-lingually and only five millimeters in mesiodistal width. The implant position was planned using simulation software (SimPlant : Materialise Dental) based on CT data and a surgical guide template (SurgiGuide : Materialise Dental) was fabricated prior to the implant surgery. During the implant surgery, the deciduous canine was extracted under local anesthesia. The implant bed was prepared with the surgical guide template and an implant was installed. One month after surgery, the position of the implant was examined with a cone-beam CT, which demonstrated that the implant position was exactly the same as planned. At 5 months, a provisional prosthesis was delivered and optimal soft-tissue condition was formed by modifying the provisional prosthesis. Then, the final impression was taken and a ceramo-metal implant-supported crown was delivered. In this case of a congenital tooth missing region with narrow space, implant treatment with simulation software and the surgical guide system provided excellent clinical results. PMID:19938675

Shiota, Makoto; Kihara, Hidemichi; Fujii, Masaki; Kasugai, Shohei

2009-10-01

264

Effect of tooth layers' segmentation on pattern of stress distribution in bracket adhesive tooth system  

Microsoft Academic Search

Orthodontic braces are used to modify, malocclusions of teeth and jaws. Most of problems in dentistry can be investigated from a biomechanical point of view. Stress distribution in bracket, adhesive and tooth has been used as a criterion to determine bond strength of bracket- adhesive- tooth system. Tooth is consisted of three layers including enamel, dentin and pulp with three

Maryam Hajizadeh; Behnam Mirzakouchaki; Farzan Ghalichi

2011-01-01

265

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

266

Electric-acoustic pitch comparisons in single-sided-deaf cochlear implant users: frequency-place functions and rate pitch.  

PubMed

Eight cochlear implant users with near-normal hearing in their non-implanted ear compared pitch percepts for pulsatile electric and acoustic pure-tone stimuli presented to the two ears. Six subjects were implanted with a 31-mm MED-EL FLEX(SOFT) electrode, and two with a 24-mm medium (M) electrode, with insertion angles of the most apical contacts ranging from 565° to 758°. In the first experiment, frequency-place functions were derived from pure-tone matches to 1500-pps unmodulated pulse trains presented to individual electrodes and compared to Greenwood's frequency position map along the organ of Corti. While the overall median downward shift of the obtained frequency-place functions (-0.16 octaves re. Greenwood) and the mean shifts in the basal (<240°; -0.33 octaves) and middle (-0.35 octaves) regions were statistically significant, the shift in the apical region (>480°; 0.26 octaves) was not. Standard deviations of frequency-place functions were approximately half an octave at electrode insertion angles below 480°, increasing to an octave at higher angular locations while individual functions were gradually leveling off. In a second experiment, subjects matched the rates of unmodulated pulse trains presented to individual electrodes in the apical half of the array to low-frequency pure tones between 100 Hz and 450 Hz. The aim was to investigate the influence of electrode place on the salience of temporal pitch cues, for coding strategies that present temporal fine structure information via rate modulations on select apical channels. Most subjects achieved reliable matches to tone frequencies from 100 Hz to 300 Hz only on electrodes at angular insertion depths beyond 360°, while rate-matches to 450-Hz tones were primarily achieved on electrodes at shallower insertion angles. Only for electrodes in the second turn the average slopes of rate-pitch functions did not differ significantly from the pure-tone references, suggesting their use for the encoding of within-channel fine frequency information via rate modulations in temporal fine structure stimulation strategies. PMID:24252455

Schatzer, Reinhold; Vermeire, Katrien; Visser, Daniel; Krenmayr, Andreas; Kals, Mathias; Voormolen, Maurits; Van de Heyning, Paul; Zierhofer, Clemens

2014-03-01

267

Tapered implants: from indications to advantages.  

PubMed

Tapered implants have become routine for immediate implant placement after tooth extraction. It seemed extremely advantageous to use tapered implants in type 4 bone, where primary stability is difficult to achieve. The authors established a surgical implant placement protocol to be followed in areas where type 4 bone and a wide bone ridge (> or = 8 mm) are present. First, preparation of the implant alveolus is done exclusively with cylindric osteotomes, rather than with conic osteotomes or drills. The final cylindric osteotome is the same diameter as the final twist drill that is typically used in conventional preparation of the implant alveolus (a technique that can be adapted for use with other tapered implants). Because of the self-tapping property of the tapered implant used and its anatomic design, this surgical technique was developed to optimize the bone compaction effect in the coronal third of the implant, improving bone density and providing better primary stability values (> or = 70 ISO, via the Osstell Mentor device). With the strong bond that is created between the implant surface and the surrounding bone using this technique, immediate loading can be predictable, even in the type 4 bone that is commonly found in the maxillary tuberosity. PMID:19408478

Alves, Célia Coutinho; Neves, Manuel

2009-04-01

268

21 CFR 872.3690 - Tooth shade resin material.  

...2014-04-01 2014-04-01 false Tooth shade resin material. 872.3690 Section 872.3690...Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of...

2014-04-01

269

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

270

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Tooth shade resin material. 872.3690 Section 872.3690...Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of...

2011-04-01

271

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

272

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

273

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Tooth shade resin material. 872.3690 Section 872.3690...Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of...

2013-04-01

274

21 CFR 872.3200 - Resin tooth bonding agent.  

...2014-04-01 2014-04-01 false Resin tooth bonding agent. 872.3200 Section...DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device...

2014-04-01

275

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

276

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

277

About Kids' Teeth: Baby Tooth Decay is Real  

MedlinePLUS

... Tooth Decay Thumb sucking Prevent Decay Nutrition Baby Tooth Decay Is Real As soon as teeth appear in ... news – decay is mostly preventable . What Are Cavities? Causes of Decay Tooth decay begins when cavity- ...

278

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2010 CFR

...2012-04-01 false Preformed plastic denture tooth. 872.3590 Section 872.3590 Food...872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated device, composed...

2012-04-01

279

21 CFR 872.5525 - Preformed tooth positioner.  

Code of Federal Regulations, 2010 CFR

...2012-04-01 2012-04-01 false Preformed tooth positioner. 872.5525 Section 872...Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that...

2012-04-01

280

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2010 CFR

...2012-04-01 2012-04-01 false Resin tooth bonding agent. 872.3200 Section 872...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material,...

2012-04-01

281

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2010 CFR

... 2012-04-01 2012-04-01 false Tooth shade resin material. 872.3690 Section...DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device...

2012-04-01

282

21 CFR 872.5525 - Preformed tooth positioner.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

283

21 CFR 872.5525 - Preformed tooth positioner.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Preformed tooth positioner. 872.5525 Section 872...Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that...

2009-04-01

284

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Resin tooth bonding agent. 872.3200 Section 872...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material,...

2009-04-01

285

21 CFR 872.3590 - Preformed plastic denture tooth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Preformed plastic denture tooth. 872.3590 Section 872.3590 Food...872.3590 Preformed plastic denture tooth. (a) Identification. A preformed plastic denture tooth is a prefabricated device, composed...

2010-04-01

286

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Preformed gold denture tooth. 872.3580 Section 872.3580 Food...Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of austenitic...

2009-04-01

287

21 CFR 872.3580 - Preformed gold denture tooth.  

...2014-04-01 2014-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

2014-04-01

288

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

2010-04-01

289

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

2011-04-01

290

21 CFR 872.3580 - Preformed gold denture tooth.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Preformed gold denture tooth. 872.3580 Section 872...Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a) Identification. A preformed gold denture tooth is a device composed of...

2012-04-01

291

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

PubMed Central

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

2013-01-01

292

[Esthetic IMZ implant for a central incisor].  

PubMed

Replacement of a missing incisor with an osseo-integrated implant, presents a difficult prosthetic problem for the practitioner because of the obliqueness of the implant and its diameter smaller than the tooth to be reconstructed. Therefore, a topographic and aesthetic pre-estimation is highly desirable. The patient whose treatment is described hereafter, presents large diastemas permitting to set the missing tooth in several locations. The various options are simulated on a study model and recorded by a silicone or resin index. This index is cut out so that the implant site is clearly defined and it presents a guide rod indicating the direction of the alveolar bone. The optimal site is selected during the surgical procedure with the most favorable index depending on the residual bone. After the implant is released, the location impression, is taken using asymmetric transfer allowing a strict positioning of the implant's replica and its thread. In order to prevent the making of a triangular-shaped crown, a false transfixed core removable is built over the intramobile component of the IMZ as well as pa periodontal ring. The latter is independent and maintained by the intramobile component. It compensates the difference in diameter between the implant and the natural tooth to be reconstructed. Its finely polished but asymmetric internal aspect prevents the rotation of the device. The volume of this device is controlled by a silicone index made on the preestimation model. Both pieces are cast in gold and assembled on the implant with a positioning indes. Parallel proximal grooves increase the friction of the core and a ceramo-metal crown is built in the conventional fashion. It is temporally cemented, and periodically removed and cleansed. The absence of gingical sulcus provides an aesthetic result similar to a bridge component. PMID:2638613

Brabant, A; Lejuste, P; Andriessens, J

1989-12-01

293

Registration of localization, occlusion and occluding materials for failing screw joints in the Brånemark implant system.  

PubMed

This study is based on data from routine follow-up registration following functional loading of a consecutive number of osseointegrated prostheses at the Dental School, University of Oslo. Fifty-six patients with 240 Brånemark implants were examined 2-4 months after the implants were loaded, and a protocol form for collecting information about the status of the treatment was completed. The examinations included registration of oral hygiene, pathological alterations in soft and hard tissues, type of material used in contacting occlusal surfaces, occlusal design and technical and mechanical failures. All superstructures, except CeraOne single-tooth prostheses, were unscrewed for inspection of implant and screw joint mobility. Eighty-three per cent of the implants were found in the upper and lower frontal segments of the jaws. The survival rate for individual implants in this study was 94%, which is well within the generally accepted level for osseointegrated implant systems. Plaque and soft tissue complications were low and could not be associated with the early losses of implants. Group function was the preferred design of the occlusal contact pattern (53.4%), followed by 37% for canine guidance and about 9% for balanced articulation. Fourteen abutment screws and 7 gold screws loosened during the period between permanent loading and the first follow-up registration. A majority of the failures occurred in osseointegrated bridges occluding with complete dentures in the opposite jaw. The failing screw joints were found in 25% of the patients, which means that one fourth of the patients needed extra mending appointments. The failures are assumed to be iatrogenic, and measures to avoid them are discussed. PMID:7669867

Wie, H

1995-03-01

294

Socket preservation as a precursor of future implant placement: review of the literature and case reports.  

PubMed

Dimensional changes after tooth extraction often result in bone resorption that complicates restorations with implant or traditional prostheses. Preservation of alveolar dimensions after tooth extraction is crucial to achieve optimal esthetic and functional prosthodontic results. In addition, with the increasingly frequent use of dental implants to replace nonrestorable teeth, preservation of the existing alveolus is essential to maintain adequate bone volume for placement and stabilization of the implants. Atraumatic extraction and socket preservation techniques have been introduced to minimize bone resorption after tooth extraction. This article reviews the literature, presents clinical cases on the healing of the alveolus and its dimensional changes after tooth extraction, and discusses socket preservation techniques that have been introduced to minimize these dimensional changes. PMID:18186170

John, Vanchit; De Poi, Robert; Blanchard, Steven

2007-12-01

295

Sinus floor augmentation through a rotated palatal flap at the time of tooth extraction.  

PubMed

Rapid crestal bone resorption following maxillary tooth loss is further accentuated in the posterior regions because of pneumatization and enlargement of the maxillary sinuses. A treatment rationale that allows preservation and/or augmentation of vertical available bone at the time of posterior maxillary tooth extraction may offer numerous therapeutic benefits. The present study comprised 14 patients in whom 18 posterior maxillary teeth with no evident bone between the tooth apex and sinus floor, as estimated through preoperative radiographic analysis, were carefully extracted using a palatal approach. The empty alveolus was thoroughly debrided and incrementally filled with tricalcium phosphate. The graft material was gently pushed beyond the empty alveolus to elevate the sinus membrane using an osteotome. Primary soft tissue closure over the grafted sites was achieved by a rotated palatal flap. The distance between bone crest and sinus floor was radiographically estimated 6 to 7 months after the first procedure. Another procedure was then carried out to place the 10- to 14-mm implants, together with a bone-added osteotome sinus floor elevation. At uncovering, all implants were clinically stable, with no signs of infection. The presented surgical procedure performed at the time of extraction of posterior maxillary teeth in close proximity to the sinus floor allowed placement of implants of proper length and width, together with a bone-added osteotome sinus floor elevation during a second procedure. PMID:15119888

Nemcovsky, Carlos E; Winocur, Ephraim; Pupkin, Juan; Artzi, Zvi

2004-04-01

296

ISS protocol for EPR tooth dosimetry  

Microsoft Academic Search

The accuracy in Electron Paramagneetic Resonance (EPR) dose reconstruction with tooth enamel is affected by sample preparation, dosimetric signal amplitude evaluation and unknown dose estimate. Worldwide efforts in the field of EPR dose reconstruction with tooth enamel are focused on the optimization of the three mentioned steps in dose assessment. In the present work, the protocol implemented at ISS in

S. Onori; D. Aragno; P. Fattibene; E. Petetti; M. C. Pressello

2000-01-01

297

Anterior tooth alignment--recommendations for stability.  

PubMed

This article considers the importance of current orthodontic practice in retention and stability when considering anterior tooth alignment. Clinical Relevance: With the exponential increase of general dentist-based orthodontic systems for anterior tooth alignment, with considerably shorter treatment times, practical recommendations along with a current literature review are required to improve success and outcome of the long-term result. PMID:24930252

Aulakh, Raman; Banerji, Subir

2014-05-01

298

Addressing Tooth Decay in Head Start Children  

ERIC Educational Resources Information Center

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

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

2012-01-01

299

Immunomodulation stimulates the innervation of engineered tooth organ.  

PubMed

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

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

2014-01-01

300

The contraceptive implant.  

PubMed

Contraceptive implants provide long-acting, highly effective reversible contraception. Currently, the only subdermal implant available to women in the United States is the single rod etonogestrel implant, Implanon (N.V. Organon, Oss, the Netherlands) approved by the Food and Drug Administration in July 2006. Implanon is currently approved for 3 years of use, provides excellent efficacy throughout its use, and is easy to insert and remove. Similar to other progestin-only contraceptives, Implanon can cause irregular vaginal bleeding. Implanon has been shown to be safe to use during lactation, may improve dysmenorrhea, and does not significantly affect bone mineral density, lipid profile, or liver enzymes. PMID:17982333

Hohmann, Heather; Creinin, Mitchell D

2007-12-01

301

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

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.

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

302

Controlling the Number of Tooth Rows  

NSDL National Science Digital Library

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

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

2009-08-25

303

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

NASA Astrophysics Data System (ADS)

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

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

1996-09-01

304

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

PubMed

Tantalum pentoxide (Ta(2)O(5)) layers made by ion plating are implanted with a high fluence of keV Ti, Li, and Er ions. The resulting refractive-index profiles are given from the analysis of guided-wave propagation conditions. A comparison with spectrophotometric measurements is presented. All the implanted layers present low losses (extinction coefficient of some 10(-6)) after thermal annealing in air. Ti-implanted layers exhibit an increase in refractive index, whereas Li- and Er-implanted layers present a slight decrease in refractive index. Er-implanted layers present photoluminescent properties. PMID:21102940

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

1996-09-01

305

Periodontio-integrated implants: A revolutionary concept  

PubMed Central

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.

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

2014-01-01

306

Healing of Osseotite implants under submerged and immediate loading conditions in a single patient: a case report and interface analysis after 2 months.  

PubMed

A growing number of clinical studies show that early (2 months) and immediate loading protocols may be predictable. However, they are based on clinical stability only The aim of this case report was to document the osseointegration status of two Osseotite implants after 2 months of healing in soft bone corresponding to type IV and subjected to two distinct mechanical environments. A completely edentulous patient received a total of 11 Osseotite implants in the mandible. Six were immediately loaded to support a provisional fixed partial denture, and five were left submerged. After 2 months, two submerged and one immediately loaded implants were retrieved and processed for histologic analysis. All immediately loaded implants were clinically stable. One histologic section per implant was obtained. All implants achieved osseointegration. The bone-implant contact was 38.9% for the submerged implant and 64.2% for the immediately loaded one. In the marrow space, both implants were covered by thin, neoformed bone trabeculae. Osseointegration can be achieved after 2 months by Osseotite implants placed in soft bone in the mandible either when immediately loaded and splinted into a provisional denture retained on six implants, or when submerged and unloaded. PMID:12212681

Testori, Tiziano; Szmukler-Moncler, Serge; Francetti, Luca; Del Fabbro, Massimo; Trisi, Paolo; Weinstein, Roberto L

2002-08-01

307

Cochlear implants in China.  

PubMed

China has approximately 6 million totally deaf people according to an official survey conducted in 1990, although the actual number is probably higher. A primary cause of deafness is the use of ototoxic drugs. There does not appear to be any emergent deaf culture in China at present. As the only available medical device that can restore partial hearing to a totally deaf person, the cochlear implant has been in development in China since 1979. This paper provides an overview of cochlear implants in China and is based on a review of published materials, visits to research institutes and hospitals, and personal communication with Chinese colleagues. As of 1993, about 1,000 deaf people, including 50 children below age 12 years, have received four types of single-electrode cochlear implants that were developed and fabricated by institutions in China. These single-electrode devices have provided an aid to lip reading, but are no longer in use due to their inability to produce open-set speech recognition. Present implant research in China focuses on development of multi-electrode devices. Basic research in electrical stimulation is relatively lacking and standardized audiological evaluation for cochlear implant effectiveness needs to be developed. The present economic growth and legal system reform in China, combined with advances in implant technology, may make it possible to produce an affordable yet effective cochlear implant system. This paper discusses cochlear implants only in China, but the social and economic factors are similar in many developing countries in Asia, South America, Eastern Europe, and Africa, where a low-cost, high-performance cochlear implant system is also needed. PMID:8561684

Zeng, F G

1995-01-01

308

Intravascular implant  

US Patent & Trademark Office Database

The invention has for its object the provision of an intravascular implant that has mechanical characteristics and physiological characteristics and is very low in cell cytotoxicity and provides an intravascular implant having an implant body made of a metal material that contains gadolinium and magnesium and is free of yttrium.

2012-10-23

309

Associations between smoking and tooth loss according to reason for tooth loss  

PubMed Central

Background Smoking is associated with tooth loss. However, smoking's relationship to the specific reason for tooth loss in postmenopausal women is unknown. Methods Postmenopausal women (n = 1,106) who joined a Women's Health Initiative ancillary study (The Buffalo OsteoPerio Study) underwent oral examinations for assessment of the number of missing teeth, as well as the self-reported reasons for tooth loss. The authors obtained information about smoking status via a self-administered questionnaire. The authors calculated odds ratios (ORs) and 95 percent confidence intervals (CIs) by means of logistic regression to assess smoking's association with overall tooth loss, as well as with tooth loss due to periodontal disease (PD) and with tooth loss due to caries. Results After adjusting for age, education, income, body mass index (BMI), history of diabetes diagnosis, calcium supplement use and dental visit frequency, the authors found that heavy smokers (? 26 pack-years) were significantly more likely to report having experienced tooth loss compared with never smokers (OR = 1.82; 95 percent CI, 1.10-3.00). Smoking status, packs smoked per day, years of smoking, pack-years and years since quitting smoking were significantly associated with tooth loss due to PD. For pack-years, the association for heavy smokers compared with that for never smokers was OR = 6.83 (95 percent CI, 3.40-13.72). The study results showed no significant associations between smoking and tooth loss due to caries. Conclusions and Practical Implications Smoking may be a major factor in tooth loss due to PD. However, smoking appears to be a less important factor in tooth loss due to caries. Further study is needed to explore the etiologies by which smoking is associated with different types of tooth loss. Dentists should counsel their patients about the impact of smoking on oral health, including the risk of tooth loss due to PD.

Mai, Xiaodan; Wactawski-Wende, Jean; Hovey, Kathleen M.; LaMonte, Michael J.; Chen, Chaoru; Tezal, Mine; Genco, Robert J.

2013-01-01

310

Ultrasonic assessment of tooth structure  

NASA Astrophysics Data System (ADS)

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

Blodgett, David W.

2002-06-01

311

A pilot efficacy study with a single-rod contraceptive implant (Implanon® 1 1 Norplant® is a registered trademark of the Population Council, New York. ) in 200 Indonesian women treated for ?4 years  

Microsoft Academic Search

In this 4-year open-label, noncomparative, single-center pilot efficacy study, the contraceptive efficacy, safety, bleeding pattern and acceptability of Implanon® was studied in 200 sexually active women of proven fertility in Indonesia. All subjects received the single-rod subdermal implant Implanon, which contains 68 mg etonogestrel (3-keto-desogestrel), with an initial release rate of 67 ?g etonogestrel\\/day. Contraceptive efficacy was analyzed by calculation

Biran Affandi; Tjeerd Korver; T. B. Paul Geurts; Herjan J. T Coelingh Bennink

1999-01-01

312

Tooth bleaching with nonthermal atmospheric pressure plasma.  

PubMed

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

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

2009-04-01

313

Single-photon emission computed tomography of spontaneous liver metastasis from orthotopically implanted human colon cancer cell line stably expressing human sodium/iodide symporter reporter gene  

PubMed Central

Background We aimed to develop a mouse spontaneous liver metastasis model from an orthotopically implanted human colon cancer cell line stably expressing a human sodium/iodide symporter (NIS) reporter gene, which can be imaged with single-photon emission computed tomography (SPECT) using 99mTcO4?. Methods A recombinant plasmid containing a constitutively driven NIS gene (pcDNA3-NIS) was transfected into the human colon cancer cell line HCT116, and stable cell lines were established. The stable cells were subcutaneously injected into the nude mice. When the diameter reached 10?mm, the xenografts were excised, cut into small fragments, and orthotopically implanted into the cecal walls of another nude mice. 99mTcO4? SPECT/CT imaging was initiated 8?weeks later and repeated every 1 to 2?weeks. Results The production and function of NIS protein was confirmed in vitro by Western blotting and 99mTcO4? uptake assay. On SPECT/CT imaging, focal 99mTcO4? uptake was detected in the liver. Necropsy revealed local growth of the orthotopic colon xenografts with extensive invasion, microscopic serosal metastasis, and metastatic foci in the corresponding hepatic regions showing focal 99mTcO4? uptake. Immunohistochemistry revealed high levels of NIS expression in cells forming liver tumor, indicating that the liver tumor cells originated from the orthotopic colon xenografts. Conclusions The present proof-of-concept study provided a rationale for employing a radionuclide reporter gene for the specific visualization of spontaneous liver metastasis in living mice. This unique animal model of clinically relevant and externally detectable liver metastasis will be a powerful tool for investigating tumor biology and developing novel therapies for cancer metastasis.

2012-01-01

314

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs  

PubMed Central

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

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

2013-01-01

315

[Considerations in the treatment of tooth wear].  

PubMed

Since the origin of tooth wear (attrition, abrasion and erosion) is multi-factorial, its diagnosis is complicated but vital. The so-called Tooth Wear Evaluation System, introduced earlier, makes a systematic diagnostic approach possible. The system consists of various modules, which can be used by the practitioner depending on the goal. Two new modules have been added to the Tooth Wear Evaluation System. The Therapy Start Module can be used to determine which one of the possible treatment modalities (counseling, monitoring, or restorative treatment) should be chosen. The Level of Difficulty Module gives the practitioner indications of the level of difficulty that may be encountered during a restorative treatment. PMID:23236739

Wetselaar, P; Kuijs, R H; van Pelt, A W J; van der Zaag, J; Roeters, F J M; Lobbezoo, F

2012-11-01

316

[Management of a failing implant supporting a bar-retained maxillary overdenture by means of alveolar ridge augmentation. Implant loss and reimplantation].  

PubMed

This case report presents the treatment sequence of a 56 years old patient after he developed periimplantitis at the implant in position of tooth 22. This implant was integrated in an overdenture reconstruction connected to a soldered screw retained gold bar. The entire 2-stage procedure of implant explantation, simultaneous bone augmentation and new implant placement is documented. The onlay-graft was performed by means of the Transfer-Ring-Control System (Meisinger). The existing gold bar could be resoldered and adapted to the new implant. Accordingly the overdenture was relined and the female retainer mounted. The treatment period covered almost one year. PMID:20020591

Albrecht, Dominic; Enkling, Norbert; Mericske-Stern, Regina

2009-01-01

317

A longitudinal comparison of tooth whitening resulting from dentifrice use.  

PubMed

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

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

1998-01-01

318

A multicenter prospective evaluation of 2-months loaded Osseotite implants placed in the posterior jaws: 3-year follow-up results.  

PubMed

In this prospective study, the clinical outcome of 2-months loaded implants placed in the posterior jaws was evaluated after up to 3 years of functional loading. 405 Osseotite implants with microtextured acid-etched surface were consecutively placed in 11 fully and 164 partially edentulous patients (mean age 53.5 +/- 15.3 (S.D.) years) using a one-stage technique. 282 implants, supporting 154 restorations, were placed in the mandible, while 123 implants, supporting 75 restorations, were placed in the maxilla. A total of 99 single-tooth restorations, 119 short-span fixed bridges and 11 full-arch prostheses were applied. The mean time interval from surgery to connection of provisional restoration was 2.0 +/- 0.7 months. 9 failures were reported up to 3 years of follow-up; of these, 4 mandibular and 2 maxillary implants failed during the initial healing period (before prosthesis connection), while 3 mandibular implants failed after loading. No other complications occurred throughout the study. Life table analysis showed a cumulative survival rate of 97.5% for the mandible and 98.4% for the maxilla. Post-loading implant survival rate was 98.9% for the mandible and 100% for the maxilla. The excellent outcome of this interim report suggests that microtextured Osseotite implants in the posterior jaws may safely bear a functional load applied 2 months after insertion. The results of the present study are particularly encouraging for implants placed in the maxilla, since both a significant reduction of the healing period compared to the 6 months suggested by the classical Brånemark protocol, and an excellent post-loading function may be achieved also in low quality bone. PMID:11952735

Testori, Tiziano; Del Fabbro, Massimo; Feldman, Sylvan; Vincenzi, Gianpaolo; Sullivan, Daniel; Rossi, Renato; Anitua, Eduardo; Bianchi, Francesca; Francetti, Luca; Weinstein, Roberto L

2002-04-01

319

Three Ways To Be a Saber-Toothed Cat  

NASA Astrophysics Data System (ADS)

Saber-toothed carnivores, until now, have been divided into two groups: scimitar-toothed cats with shorter, coarsely serrated canines coupled with long legs for fast running, and dirk-toothed cats with more elongate, finely serrated canines coupled to short legs built for power rather than speed. In the Pleistocene of North America, as in Europe, the scimitar-cat was Homotherium; the North American dirk-tooth was Smilodon. We now describe a new sabercat from the Early Pleistocene of Florida, combining the scimitar-tooth canine with the short, massive limbs of a dirk-tooth predator. This presents a third way to construct a saber-toothed carnivore.

Martin, L. D.; Babiarz, J. P.; Naples, V. L.; Hearst, J.

320

Tooth cementum annulation method: accuracy and applicability.  

PubMed

Tooth cementum annulation (TCA) technique has been a frequently discussed method for the individual age estimation. Conflicting statements on its accuracy and applicability in previous publications have provoked our research. The accuracy and bias of the TCA age estimates were examined in a sample of 116 teeth from 65 individuals of known age and sex from the anatomical collection of the University of Tubingen (Germany). Incremental lines were counted on enhanced digital images of undecalcified, unstained, 60-80 microm thick cross-sections from the middle third of the root of single-rooted teeth. Maximal line counts resulted in age estimates that correlated best with the real age of the specimens. In this sample, this argument is supported by the observation that the mean number of lines increased significantly from the most cervical to the most apical section. Reasonably accurate age estimates based on TCA counts were only obtained in young adults. Both accuracy and bias continuously decreased with the increasing age of the individuals. A considerable underestimation of age occurred in individuals older than 40 years. Due to the conflicting results on the accuracy of the TCA technique this method should be used for age estimation only in association with the macroscopic examination. PMID:19828994

Obertová, Zuzana; Francken, Michael

2009-01-01

321

Biomaterials in Tooth Tissue Engineering: A Review  

PubMed Central

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

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

2014-01-01

322

Impacted Primary Tooth and Tooth Agenesis: A Case Report of Monozygotic Twins  

PubMed Central

In the present report, a case of 19 year-old monozygotic twin brothers with similar tooth agenesis and impacted primary teeth is presented. Both twins (HDH, DHH) had agenesis of ten and eleven teeth (respectively), third molars excluded, consistent with oligodontia and both had four impacted primary teeth and the permanent successors of all these primary teeth were congenitally missing. The occurrence of similarly located tooth agenesis and primary impacted teeth in monozygotic twins may suggest the influence of genetic factors in their etiology. In addition, primary tooth impaction may be related to congenitally missing tooth.

Zengin, A. Zeynep; Sumer, A. Pinar; Karaarslan, Emine

2008-01-01

323

Bioengineered Teeth from Cultured Rat Tooth Bud Cells  

Microsoft Academic Search

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

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

2004-01-01

324

Sports Safety: Avoiding Tooth and Mouth Injuries  

MedlinePLUS

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

325

Lead levels among various deciduous tooth types  

SciTech Connect

The amount of lead in deciduous teeth has been used extensively as a marker for infant lead exposure and body burden. However, the pattern of lead abundances among the various tooth positions in a child's mouth appears to be non-uniform. Taken together these findings show an apparently inconsistent pattern among the tooth types. These comparisons are complicated by different research groups using different portions of the tooth. This issue is of significance to those who wish to compare the lead burden of children but have available teeth from different positions from the various children. By examining a large number of teeth from two different populations, the authors hope to explore the more universal aspects of any variability among tooth types.

Rabinowitz, M.B. (Children's Hospital, Boston, MA (United States) National Taiwan Univ., Taipei (Taiwan)); Bellinger, D.; Leviton, A. (Children's Hospital, Boston, MA (United States)); Jungder Wang (National Taiwan Univ., Taipei (Taiwan))

1991-10-01

326

Computer simulation of gear tooth manufacturing processes  

NASA Technical Reports Server (NTRS)

The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

Mavriplis, Dimitri; Huston, Ronald L.

1990-01-01

327

Tooth microwear formation rate in Gasterosteus aculeatus.  

PubMed

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

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

2014-05-01

328

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

PubMed

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

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

2013-01-01

329

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

PubMed

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

Warpeha, Walter S

2014-01-01

330

Tooth design to avoid shearing stresses  

SciTech Connect

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

Mengel, H. E.; Munzel, H.

1985-05-07

331

Patterns in ritual tooth avulsion at Roonka.  

PubMed

Tooth avulsion is the intentional removal of one or more teeth for ritual or aesthetic reasons, or to denote group affiliation. Typically the maxillary incisors are the teeth most often selected for removal. Previous authors have discussed the presence of tooth avulsions in several individuals recovered from Roonka, but those papers did not examine any patterns in those removals that might be present. Analysis of the tooth avulsions at Roonka reveals a change in the practice over time, with the older burials from phase II typically showing removal of both maxillary central incisors with a left side bias when only one tooth is removed, and the more recent phase III burials showing only one incisor avulsed and a right side bias for removal. Frequencies in the practice also changed over time, with avulsions being much more common in the older phase II burials. Historical evidence suggests that any particular regional or social group would have its own particular pattern of tooth avulsion, so these changes in tooth avulsions at Roonka suggest that the site was either used by multiple groups of people for burials, or that there was significant cultural change during the occupation of the site. Am J Phys Anthropol 154:479-485, 2014. © 2014 Wiley Periodicals, Inc. PMID:24827419

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

2014-08-01

332

Present and future technologies of tooth whitening.  

PubMed

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

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

2000-01-01

333

Implantable Microimagers  

PubMed Central

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

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

2008-01-01

334

Twin disc gear tooth simulator  

NASA Astrophysics Data System (ADS)

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.

Eusepi, Martin W.; Dill, James F.

1994-05-01

335

Dynamic Ion Implantation.  

NASA Astrophysics Data System (ADS)

The Dynamic Ion Implantation Technique consists of ion implantation of a film during the film deposition process. This technique was investigated theoretically and experimentally with ions whose incident energy is of the order of a few times 100 keV. We found it to be a viable alternative low-temperature method for the preparation of thick zirconium nitride films (~1 ?m) with good mechanical properties. Theoretical modeling of the processes involved during dynamic ion implantation lead to analytical expressions for the ions' depth profile distributions. Numerical evaluations of these equations indicated that the depth distributions of dynamically implanted ions are in general more uniform than those predicted by the model for ions implanted by more conventional techniques like, for example, the post implantation technique. Theoretical and experimental profiles were found to be in reasonable agreement. Numerical evaluations of analytical expressions obtained with a diffusional model of the dynamic ion beam mixing pointed out the possibility of tailoring the amounts of induced mixing in order to suit experimental needs. Rutherford Backscattering Spectroscopy and Grazing Angle X-Ray Diffraction analysis indicated zirconium nitride phase formation in RF sputter deposited zirconium films (~ 5000 A) dynamically implanted with singly ionized molecular nitrogen, for ion to atom arrival ratios of the order of 0.44, and 100 keV ion incident energy. Knoop micro-hardness of samples, prepared with nitrogen to zirconium arrival ratios ranging from 0.027 to 0.44 and ion incident energies between 100 and 300 keV, were found to increase with increasing ion to atom arrival ratios and decrease with increasing energies. Mechanical properties of stoichiometric RF sputter deposited zirconium nitride films post implanted with krypton and rubidium ions were investigated. Scratch-adhesion critical load and Vickers micro-hardness of samples implanted with doses varying from 1 times 10 ^{15} to 5 times 10^{16} ions/cm ^2 and energies ranging from 300 to 500 keV were studied. In general, best mechanical properties were observed for 300-keV krypton implantations. At this energy and an implanted dose of 1 times 10^{15} ion/cm ^2, an increment of the order of 60% in micro -hardness was obtained for the implanted sample with respect to the as-deposited sample.

Oppenheim, Ivette F. C.

336

High Productivity Implantation ``PARTIAL IMPLANT''  

NASA Astrophysics Data System (ADS)

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

Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao

2008-11-01

337

Ion Implantation  

NASA Astrophysics Data System (ADS)

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.

Langouche, G.; Yoshida, Y.

338

Time required to remove totally bonded tooth-colored posterior restorations and related tooth substance loss  

Microsoft Academic Search

Objectives. The study was conducted to measure the time required to remove large totally bonded tooth-colored posterior restorations and related tooth substance loss. This information was collected to determine if there were differences between bonded restorations and conventional restorations. Methods. Molars were restored with the following materials: amalgam, composite, glass ionomer cement or glass ceramic cusp coverages. After submitting them

Ivo Krejci; Claudia M. Lieber; Felix Lutz

1995-01-01

339

[Tooth wear, a proposal for an evaluation system].  

PubMed

The present-day terminology and definitions of tooth wear are not unambiguous. For diagnosing tooth wear, however, it is essential that they are unambiguous. In this article a proposal is presented for a tooth wear evaluation system with simplified definitions. This system consists ofa number of modules and can be used for various aspects of the diagnostic procedure. It can be used for the quantification of tooth wear, both for periodic screening and for the monitoring of tooth wear in individual patients. The scoring of occlusal/incisal tooth wear as well as of non-occlusal/non-incisal tooth wear is possible. The evaluative system is also suitable for determining which type of tooth wear, such as attrition, abrasion and erosion, is most likely to have caused any observed loss of hard tooth tissue. PMID:21761796

Wetselaar, P; van der Zaag, J; Lobbezoo, F

2011-06-01

340

Tooth Wear Prevalence and Sample Size Determination : A Pilot Study  

PubMed Central

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

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

2008-01-01

341

Oxygen implanter for simox  

Microsoft Academic Search

Interest in silicon or) insulator (SOI) technology has led to the development of several alternatives to silicon on sapphire. One of the most promising techniques makes use of an ion implanter to form a buried oxide layer directly in the silicon substrate. To have useful single crystalline silicon on top of the oxide layer, it is necessary to do the

M. Guerra; V. Benveniste; G. Ryding; D. H. Douglas-Hamilton; M. Reed; G. Gagne; A. Armstrong; M. Mack

1985-01-01

342

The biomechanics of force distribution in implant-supported prostheses.  

PubMed

Force distribution with natural teeth depends on micromovement induced by the periodontal ligament. The location and cusp inclination of the tooth qualitatively alter the force pattern. Osseointegrated implants do not have micromovement associated with force distribution. Force distribution to the osseointegrated implant interface is completely different than with natural teeth. Alterations in tooth location and cusp inclination are suggested to limit implant overload. Force distribution in splinted natural teeth and osseointegrated prostheses are compared. The mechanism of interface force distribution and the consequences of poor interface fit are interrelated. The differential mobility of splinted natural teeth affects diagnosis and treatment. However, combining natural teeth with an osseointegrated prosthesis requires new design principles. PMID:8468083

Weinberg, L A

1993-01-01

343

Multiferroic nanoparticulate thin film composites by Co implantation of ferroelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal targets  

NASA Astrophysics Data System (ADS)

Two-phase magnetostrictive-piezoelectric thin film composites are key materials to the development of a range of potentially disruptive magnetoelectric technologies, such as electrical-writing magnetic-reading random access memories. However, multiferroic thin film composites prepared so far show neither magnetoelectric switching nor magnetoelectric responses comparable to those of related bulk ceramic materials and cermets. Here we show that ion implantation of magnetic species into ferroelectric single crystal targets can be an effective alternative means of obtaining nanoparticulate thin film composites of this type. Concept is proved by the implantation of Co into a Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal with ultrahigh piezoelectricity. Formation of an ensemble of ferromagnetic nanoparticles embedded in an amorphized layer within the ferroelectric crystal is clearly shown.

Torres, María; Ricote, Jesús; Amorín, Harvey; Jaafar, Miriam; Holgado, Susana; Piqueras, Juan; Asenjo, Agustina; García-Hernández, Mar; Algueró, Miguel

2011-12-01

344

Practicability of a tooth rescue concept--the use of a tooth rescue box.  

PubMed

Healing following replantation of avulsed teeth is dependent upon short unphysiologic periods during the extraalveolar phase. A commercially available tooth rescue box was developed and distributed at schools in Hessen, a state in Germany. Aim of the study was to evaluate the availability times of rescue boxes and the storage periods of rescued teeth within the boxes. Two thousand one hundred tooth rescue boxes together with a questionnaire were distributed predominantly at schools. In case of usage of a box, the questionnaire should be filled out by patients and dentists and sent back for evaluation. One hundred seventy-two (8.2%) questionnaires were sent back. Eighteen questionnaires were incomplete. In the remaining 154 tooth rescue boxes, a total of 201 avulsed teeth and tooth crown fragments were rescued. When accidents occurred near a stored rescue box, the availability time was short (median: 5 min). It was significantly longer (median: 35 min) when the location of the accident was distant to a stored box. Storage of avulsed teeth in the tooth rescue box was longer (median: 2 h) than storage of fractured crown fragments (median: 1 h). Lay people (teachers, pupils) used the rescue boxes correctly without professional help or even advice through telephone. The usage of the tooth rescue box seemed to be self-explanatory and plausible to lay persons, very short availability times resulted when accidents occurred near stored boxes. Thus, an excellent healing prognosis can be anticipated after replantation. The storage periods of avulsed teeth before the commencement of treatment exceed by far the periods that are acceptable for alternative but unphysiologic media (saline, saliva, milk). It is concluded that tooth rescue boxes should be distributed at locations prone to tooth traumas (schools, kindergartens, sporting facilities, public pools) to enhance the prognosis of avulsed teeth. Emergency units (hospitals, ambulances) should be equipped with tooth rescue boxes as well as every dentist. Tooth rescue boxes are recommended for families with children. PMID:18721341

Filippi, Cornelia; Kirschner, Horst; Filippi, Andreas; Pohl, Yango

2008-08-01

345

[Implant allergies].  

PubMed

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

Thomas, P; Thomsen, M

2010-03-01

346

Breast Implants  

MedlinePLUS

... result of an original surgery. There are two types of breast implants approved for sale in the United States: saline- ... Encourage reporting of adverse events associated with breast implants through our Medwatch Reporting System. Related Links Medscape Interview with FDA staff on ...

347

Adhesion to tooth structure: A critical review of “micro” bond strength test methods  

Microsoft Academic Search

The objective of this paper is to critically review the literature regarding the mechanics, geometry, load application and other testing parameters of “micro” shear and tensile adhesion tests, and to outline their advantages and limitations. The testing of multiple specimens from a single tooth conserves teeth and allows research designs not possible using conventional ‘macro’ methods. Specimen fabrication, gripping and

Steve Armstrong; Saulo Geraldeli; Rodrigo Maia; Luís Henrique Araújo Raposo; Carlos José Soares; Junichiro Yamagawa

2010-01-01

348

Surgical treatment of an unerupted supernumerary tooth attached to an unerupted permanent incisor  

Microsoft Academic Search

An unerupted supernumerary tooth was attached to the root surface of an unerupted permanent lateral incisor. It was necessary to remove both the supernumerary and the permanent lateral incisor as a single unit. The permanent lateral incisor was separated from the supernumerary and placed back into the original developmental crypt. The replanted lateral incisor erupted normally one year later.

Mark V. Barren

1983-01-01

349

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

PubMed

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

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

2014-05-01

350

Risks of Breast Implants  

MedlinePLUS

... Booklet Anaplastic Large Cell Lymphoma (ALCL) Other Resources Risks of Breast Implants Risks of Breast Implants Implant ... Getting Breast Implants (Available in text and PDF) Risks of Breast Implants Some of the complications and ...

351

Twin Tooth on Either Side: A Case Report of Bilateral Gemination  

PubMed Central

Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development, resulting in a bifid crown. They are found more frequently in the primary than in the permanent dentition unilaterally, but bilateral gemination is very rare. It is caused by complex interactions among a variety of genetic and environmental factors. This developmental anomaly may cause clinical problems including esthetic impairment, periodontal problems, caries, and tooth crowding. Here, we report a unique case of bilateral gemination of permanent maxillary central incisors.

Rao, PK; Veena, KM; Chatra, L; Shenai, P

2013-01-01

352

Detecting Tooth Damage in Geared Drive Trains  

NASA Technical Reports Server (NTRS)

This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

Nachtsheim, Philip R.

1997-01-01

353

Kinematics of the tooth tapping movement.  

PubMed

Electrical activity in the masseter muscles and tooth contact vibrations were recorded simultaneously from subjects tapping their teeth slowly into maximal intercuspidation and again with maximal frequency. High speed cinephotography was also used with four of the ten subjects. Three main parts could be distinguished on the obtained graphical representation of the tooth tapping movement: tooth contact phase (TCP), opening phase (OP) and closing phase (CP). Tapping frequency was increased by decreasing the jaw opening degree and the durations of TCP, OP and CP. The jaw velocity immediately before tooth contact, which may be of significance for the reflex response, was however not increased. The average jaw speed was nevertheless increased from 10 to 15 cm/s since the turning from OP to CP was more abrupt in high than in low frequency tapping. The duration of electrical activity after tooth contact was significantly shorter at tapping with high than with low frequency. The teeth maintained contact without detectable rebound between each open-close cycle. The OP started about 100 ms after the cessation of electrical activity both at low and high tapping frequency. The time between end of electrical activity and the start of a new OP was supposed to be dependent upon the relaxation time of the masseter muscles. PMID:268419

Widmalm, S E; Hedegård, B

1977-07-01

354

The use of definitive implant abutments for the fabrication of provisional crowns: a case series  

PubMed Central

Purpose The anterior region is a challenge for most clinicians to achieve optimal esthetics with dental implants. The provisional crown is a key factor in the success of obtaining pink esthetics around restorations with single implants, by soft tissue and inter-proximal papilla shaping. Provisional abutments bring additional costs and make the treatment more expensive. Since one of the aims of the clinician is to reduce costs and find more economic ways to raise patient satisfaction, this paper describes a practical method for chair-side fabrication of non-occlusal loaded provisional crowns used by the authors for several years successfully. Methods Twenty two patients (9 males, 13 females; mean age, 36,72 years) with one missing anterior tooth were treated by using the presented method. Metal definitive abutments instead of provisional abutments were used and provisional crowns were fabricated on the definitive abutments for all of the patients. The marginal fit was finished on a laboratory analogue and temporarily cemented to the abutments. The marginal adaptation of the crowns was evaluated radiographically. Results The patients were all satisfied with the final appearance and no complications occurred until the implants were loaded with permanent restorations. Conclusions The use of the definitive abutments for provisional crowns instead of provisional abutments reduces the costs and the same results can be obtained.

Bilhan, Hakan; Mumcu, Emre

2011-01-01

355

'Your whole life is lived through your teeth': biographical disruption and experiences of tooth loss and replacement.  

PubMed

The experience and meaning of tooth loss and replacement has varied historically and culturally but has received relatively little attention from social scientists. Our study set out to understand these experiences in the context of the arrival of newer, dental implant treatments. Semi-structured qualitative interviews were carried out with 39 men and women who had experienced tooth loss and replacement. A thematic analysis was sensitised by previous sociological work on chronic illness, particularly Bury's notion of biographical disruption. We found that while for some individuals the loss of a tooth was relatively insignificant, for others it was devastating and disruptive. In seeking to understand this difference, the concept of biographical disruption was a helpful analytical tool. Our analysis identified two forms of disruption. The first related to the meanings of tooth loss (the neglected mouth) and denture wearing (a marker of old age). The second, embodied, disruption concerned the relationship between the self and mouth in those wearing dentures (the invaded, unreliable mouth) and could occur even where tooth loss and denture wearing had been biographically anticipated. PMID:24720855

Rousseau, Nikki; Steele, Jimmy; May, Carl; Exley, Catherine

2014-03-01

356

Ridge preservation and augmentation using regenerative materials to enhance implant predictability and esthetics.  

PubMed

Dentistry has entered an era in which patients no longer need to accept an edentulous or partially edentulous condition, or one in which their candidacy for tooth structure replacement (ie, implants with subsequent restoration) must be dismissed because of insufficient alveolar bone volume, height, or width. The supporting bone can be preserved at the time of tooth extraction, or augmented at the time of case presentation, using a variety of available regenerative materials. Among them are mineralized human allograft bone and collagen membranes that can be placed in combination with specific growth factor complexes and implant designs. This article reviews the challenges associated with adequately preserving or augmenting the alveolar bone after tooth extraction or loss and before implant placement. The research and benefits to support using allogenic bone graft and membrane materials for such procedures are detailed, and 3 clinical cases are presented to demonstrate the clinically successful incorporation of these materials with the host tissues. PMID:18064786

Keith, J Daulton; Salama, Maurice A

2007-11-01

357

Plasticity of the cortical dentition representation after tooth extraction in naked mole-rats.  

PubMed

Naked mole-rats (Heterocephalus glaber) have a large cortical representation of their behaviorally important front teeth, accounting for 30% of primary somatosensory cortex (SI). Here we investigated the plasticity of this dental representation after the extraction of a single lower tooth. The representation of the contralateral lower incisor normally accounts for approximately 15% of somatosensory cortex in mole-rats. In five mole-rats the lower right incisor was extracted on either postnatal day 7 or 21. After 5-8 months the deprived tooth zone in S1 was investigated with multiunit microelectrode recordings. The results revealed a dramatic reorganization of the orofacial representation in SI. Neurons in the cortical lower tooth representation were responsive to tactile inputs from surrounding orofacial structures, including the contralateral upper incisor, ipsilateral lower incisor, tongue, chin, gums, and buccal pad. Neurons in the former lower tooth zone had complex receptive fields that often encompassed multiple sensory surfaces surrounding the extracted tooth in the periphery. These results suggest that the representation of the dentition in mammals is capable of significant reorganization after the loss of sensory inputs from the teeth. These data parallel findings in the somatosensory hand area of primates after deafferentation where cortex can become activated by a mixture of widely spaced surrounding sensory surfaces (e.g., chin and upper arm). PMID:15776439

Henry, Erin C; Marasco, Paul D; Catania, Kenneth C

2005-04-25

358

Second harmonic generation in single-crystal thin membranes of LiNbO3 fabricated by patterned He+ ion implantation  

Microsoft Academic Search

We demonstrate room-temperature phase matching of second-harmonic generation by waveguide dispersion (WGD) in 3-mum-thick LiNbO3 membranes. The membranes were made using patterned deep-ion-implantation-guided etching.

O. Gaathon; A. Ofan; D. Djukic; J. I. Dadap; R. M. Osgood; S. Bakhru; H. Bakhru

2008-01-01

359

Tooth-derived bone graft material  

PubMed Central

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

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

2013-01-01

360

Tooth wear: attrition, erosion, and abrasion.  

PubMed

Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification acts through a distinct process that is associated with unique clinical characteristics. Accurate prevalence data for each classification are not available since indices do not necessarily measure one specific etiology, or the study populations may be too diverse in age and characteristics. The treatment of teeth in each classification will depend on identifying the factors associated with each etiology. Some cases may require specific restorative procedures, while others will not require treatment. A review of the literature points to the interaction of the three entities in the initiation and progression of lesions that may act synchronously or sequentially, synergistically or additively, or in conjunction with other entities to mask the true nature of tooth wear, which appears to be multifactorial. PMID:12859088

Litonjua, Luis A; Andreana, Sebastiano; Bush, Peter J; Cohen, Robert E

2003-06-01

361

PKA regulatory subunit expression in tooth development.  

PubMed

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

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

2014-05-01

362

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

PubMed

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

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

2013-11-01

363

Are You Feeding Your Kids Tooth-Friendly Foods?  

MedlinePLUS

... do: Recognize foods that are "high risk" for tooth decay. Most people know that sweets such as cookies, ... nutritious diet is just one way of preventing tooth decay. Be sure that your child also brushes twice ...

364

Genetics Home Reference: Charcot-Marie-Tooth disease  

MedlinePLUS

... early adulthood, but onset may occur anytime from early childhood through late adulthood. Symptoms of Charcot-Marie-Tooth ... a term sometimes used to describe a severe, early childhood form of Charcot-Marie-Tooth disease; it is ...

365

Interactive tooth segmentation of dental models.  

PubMed

The accurate segmentation of the teeth from the triangle mesh is an important step in computer-aided orthodontic. Because teeth come in different shapes and their arrangements vary substantially from one individual to another, tooth segmentation is difficult. This paper proposes a new method to accurately segment the teeth interactively. Based on curvature values of the triangle mesh, feature points are connected to feature regions. After feature lines are extracted from regions, feature contour can be obtained with the help of user supplied information. Using feature contour, the tooth are segmented accurately and individually. PMID:17282267

Zhao, Mingxi; Ma, Lizhuang; Tan, Wuzheng; Nie, Dongdong

2005-01-01

366

Ectopic tooth in maxillary sinus: Case series  

PubMed Central

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

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

2013-01-01

367

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

PubMed Central

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

Purra, Aamir Rashid; Mushtaq, Mubashir

2013-01-01

368

Treatment planning: implant-supported partial overdentures.  

PubMed

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

Chee, Winston W L

2005-04-01

369

Tooth discoloration induced by endodontic materials: a literature review.  

PubMed

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

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

2013-02-01

370

The Effect of Lubricants on Gear Tooth Scuffing  

Microsoft Academic Search

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

P. M. Ku; B. B. Baber

1959-01-01

371

Noncontact intraoral measurement of force-related tooth mobility  

Microsoft Academic Search

The aim of this pilot study was to measure force-related tooth mobility. Vertical and horizontal anterior tooth mobility in\\u000a 31 healthy periodontal subjects was measured by a noncontact optical measurement technique. The subjects continuously increased\\u000a the force on each tooth by biting on a load cell. An automated software program recorded tooth displacement at 9-N intervals.\\u000a Vertical and horizontal displacements

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

2010-01-01

372

Immediate placement of bone level Sraumann implants: a case series.  

PubMed

Endosseous dental implants have revolutionized the methods clinicians use to treat edentulous and partially edentulous patients. Traditional implant protocol specifies a healing period of several months after tooth extraction, as well as an unloaded healing period prior to restoration. Over the last decade, numerous studies have documented successful immediate placement of endosseous dental implants in fresh extraction sites and have found positive results with early functional loading. The purpose of this article is to present a clinical treatment protocol for the immediate placement and early loading of dental implants and to report the clinical and radiographic outcomes of the SLActive surface Straumann Bone Level implant placed in either maxillary or mandibular fresh extraction sockets. PMID:21365027

Di Felice, Roberto; D'Amario, Maurizio; De Dominicis, Alessandro; Garocchio, Santo; D'Arcangelo, Camillo; Giannoni, Mario

2011-02-01

373

Tooth slice organ culture for cytotoxicity assessment of dental materials  

Microsoft Academic Search

The purpose of this work was to develop a tooth slice organ culture method to assess the response of the cells of the dental pulp to commonly used dental materials and products. Wistar rat tooth slices were grown in culture for two and ten days in the presence of dental materials. After culture, the tooth tissues were processed and the

Peter E Murray; Philip J Lumley; Hamish F Ross; Anthony J Smith

2000-01-01

374

Tooth Replacement in the Lemon Shark, Negaprion Brevirostris.  

National Technical Information Service (NTIS)

The tooth-replacement rates of the lemon shark, Negarprion brevirostris, upper- and lower-jaw teeth were measured by experimental clipping of teeth followed by the plotting of tooth movements. Lower-jaw teeth were replaced at an average rate of one tooth ...

S. A. Moss

1967-01-01

375

Computerized Inspection Of Gear-Tooth Surfaces  

NASA Technical Reports Server (NTRS)

Method of manufacturing gears with precisely shaped teeth involves computerized inspection of gear-tooth surfaces followed by adjustments of machine-tool settings to minimize deviations between real and theoretical versions of surfaces. Thus, iterated cycles of cutting gear teeth, inspection, and adjustments help increase and/or maintain precision of subsequently manufactured gears.

Handschuh, R. F.; Litvin, F. L.; Zhang, Y.; Kuan, C.

1994-01-01

376

Tooth loss and obstructive sleep apnoea  

Microsoft Academic Search

BACKGROUND: Complete tooth loss (edentulism) produces anatomical changes that may impair upper airway size and function. The aim of this study was to evaluate whether edentulism favours the occurrence of obstructive sleep apnoea (OSA). METHODS: Polysomnography was performed in 48 edentulous subjects on two consecutive nights, one slept with and the other without dentures. Upper airway size was assessed by

Caterina Bucca; Alessandro Cicolin; Luisa Brussino; Andrea Arienti; Alessandra Graziano; Francesco Erovigni; Paolo Pera; Valerio Gai; Roberto Mutani; Giulio Preti; Giovanni Rolla; Stefano Carossa

2006-01-01

377

Japanese tooth size: past and present.  

PubMed

Mesial-distal and buccal-lingual crown measurements were made on male and female samples of recent Japanese teeth from three locations, Fukuoka, Kyoto, and Tokyo, and for Hokkaido Ainu and Koreans. Similar data were collected for prehistoric Middle-to-Late Jomon Japanese and from Yayoi specimens representing the first agriculturalists to appear in Japan. From a tooth-by-tooth comparison of cross-sectional areas, it was shown that the modern Japanese samples did not differ from one part of Japan to another. Korean tooth size also is not significantly different from Japanese, while Ainu have the smallest teeth recorded in Asia. The Yayoi who brought rice to Japan about 300 B.C. came in with teeth that were the same size as Chinese Neolithic teeth. They encountered a resident Jomon population whose teeth were 10% smaller. From tooth size measures alone, it is most economical to suggest that, if the rates of reduction observed elsewhere in the world applied in Japan, the recent Ainu would best be regarded as the direct descendants of the Jomon, while the modern Japanese are the results of in situ reduction from the incoming Yayoi. Other aspects of craniofacial morphology suggest that some Jomon was incorporated by the Yayoi. The modern Japanese, then, while predominantly derived from the Yayoi, would include a Jomon component. PMID:6762098

Brace, C L; Nagai, M

1982-12-01

378

Gastroesophageal Reflux Disease and Tooth Erosion  

PubMed Central

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

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

2012-01-01

379

EPR dosimetry with tooth enamel: A review.  

PubMed

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

Fattibene, Paola; Callens, Freddy

2010-11-01

380

Dynamic Tooth Loads for Spur Gears  

NASA Technical Reports Server (NTRS)

Computer program developed using time-history, interactive, closed-form solution for dynamic tooth loads for both low- and high-contact-ratio spur gears. Facilitates application of high-contact-ratio spur gear concepts. Program written in FORTRAN IV.

Cornell, R.; Westervelt, W.

1986-01-01

381

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

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

382

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

PubMed Central

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

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

2012-01-01

383

Efficacy and Safety of High-Dose-Rate Brachytherapy of Single Implant with Two Fractions Combined with External Beam Radiotherapy for Hormone-Na?ve Localized Prostate Cancer  

PubMed Central

The purpose of this study was to evaluate the efficacy and safety of high-dose-rate (HDR) brachytherapy of a single implant with two fractions plus external beam radiotherapy (EBRT) for hormone-naïve prostate cancer in comparison with radical prostatectomy. Of 150 patients with localized prostate cancer (T1c–T2c), 59 underwent HDR brachytherapy plus EBRT, and 91 received radical prostatectomy. The median follow-up of patients was 62 months for HDR brachytherapy plus EBRT, and 64 months for radical prostatectomy. In patient backgrounds between the two cohorts, the frequency of T2b plus T2c was greater in HDR brachytherapy cohort than in prostatectomy cohort (27% versus 12%, p = 0.029). Patients in HDR brachytherapy cohort first underwent 3D conformal RT with four beams to the prostate to an isocentric dose of 50 Gy in 25 fractions and then, a total of 15–18 Gy in two fractions at least 5 hours apart. We prescribed 9 Gy/fraction for target (prostate gland plus 3 mm lateral outside margin and seminal vesicle) using CT image method for radiation planning. The total biochemical failure-free control rates (BF-FCR) at 3 and 5 years for the HDR brachytherapy cohort, and for the prostatectomy cohort were 92% and 85%, and 72% and 72%, respectively (significant difference, p = 0.0012). The 3-and 5-year BF-FCR in the HDR brachytherapy cohort and in the prostatectomy cohort by risk group was 100 and 100%, and 80 and 80%, respectively, for the low-risk group (p = 0.1418); 92 and 92%, 73 and 73%, respectively, for the intermediate-risk group (p = 0.0492); and 94 and 72%, 45 and 45%, respectively, for the high-risk group (p = 0.0073). After HDR brachytherapy plus EBRT, no patient experienced Grade 2 or greater genitourinay toxicity. The rate of late Grade 1 and 2 GI toxicity was 6% (n = 4). No patient experienced Grade 3 GI toxicity. HDR brachytherapy plus EBRT is useful for treating patients with hormone-naïve localized prostate cancer, and has low GU and GI toxicities.

Noda, Yasutaka; Sato, Morio; Shirai, Shintaro; Kishi, Kazushi; Inagaki, Takeshi; Mori, Takeshi; Hara, Isao

2011-01-01

384

An evaluation of dynamic lip-tooth characteristics during speech and smile in adolescents.  

PubMed

This retrospective study was conducted to measure lip-tooth characteristics of adolescents. Pretreatment video clips of 1242 consecutive patients were screened for Class-I skeletal and dental patterns. After all inclusion criteria were applied, the final sample consisted of 50 patients (27 boys, 23 girls) with a mean age of 12.5 years. The raw digital video stream of each patient was edited to select a single image frame representing the patient saying the syllable "chee" and a second single image representing the patient's posed social smile and saved as part of a 12-frame image sequence. Each animation image was analyzed using a SmileMesh computer application to measure the smile index (the ratio of the intercommissure width divided by the interlabial gap), intercommissure width (mm), interlabial gap (mm), percent incisor below the intercommissure line, and maximum incisor exposure (mm). The data were analyzed using SAS (version 8.1). All recorded differences in linear measures had to be > or = 2 mm. The results suggest that anterior tooth display at speech and smile should be recorded independently but evaluated as part of a dynamic range. Asking patients to say "cheese" and then smile is no longer a valid method to elicit the parameters of anterior tooth display. When planning the vertical positions of incisors during orthodontic treatment, the orthodontist should view the dynamics of anterior tooth display as a continuum delineated by the time points of rest, speech, posed social smile, and a Duchenne smile. PMID:15038490

Ackerman, Marc B; Brensinger, Colleen; Landis, J Richard

2004-02-01

385

Detecting inter-cusp and inter-tooth wear patterns in rhinocerotids.  

PubMed

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

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

2013-01-01

386

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

PubMed Central

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

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

2014-01-01

387

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

SciTech Connect

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

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

2013-07-15

388

'Split posterior tooth': conservative clinical re-attachment.  

PubMed

Trauma is the prime causative factor for fracture of teeth/dentition. Many procedural management options are followed successfully in relation to the anterior teeth. However, most posterior cases where the tooth is fractured have only limited options to pursue to save the tooth. Fractured teeth, whether they are vital/non-vital, are predominantly managed with surgical options. This paper discusses a conservative approach to reattaching a split posterior tooth. A split tooth situation is mostly an absolute indication for extraction, but the clinician may go in for extensive surgical procedures if he/she wishes to save it. The reattachment of the tooth can be successfully done and it can be put to function. This paper discusses how a split posterior tooth can be treated successfully, although depending on multiple factors. A full crown cemented after successful reattachment and root canal therapy would provide sufficient support in order for the tooth to heal. PMID:25080545

Abraham, Sathish; Chacko, Lisa Neelathil

2014-01-01

389

Multidisciplinary Management of a Fused Tooth: A Case Report  

PubMed Central

Objective. Fusion is a dental anomaly that arises through the union of two adjacent teeth. The case report presents multidisciplinary management of a fused maxillary anterior tooth. Case Report. A 10-year-old boy was referred to the pediatric dental clinic with the chief complaint of a large upper anterior tooth. Intraoral and radiographic examinations indicated fusion between the permanent maxillary right central incisor and a supernumerary tooth. According to the treatment plan, the fused tooth was sectioned, and the mesial portion was removed. The remaining tooth section was restored with composite resin, and the diastema between the central incisors was closed with orthodontic treatment. After an 18-month followup period, the tooth showed no sign of pathosis. Conclusion. The technique described here offers a simple and effective method for restoring a fused tooth that reestablishes function, shape, and esthetics.

Sen Tunc, Emine; Arici, Nursel; Ozkan, Nilufer

2013-01-01

390

Dynamic analysis of straight and involute tooth forms  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

391

Implant-Supported Denture  

MedlinePLUS

... interfere with the placement of implants. The time frame to complete the implant and denture depends on ... the type of implant used. The shortest time frame for standard implants is about five months for ...

392

Successful pregnancy outcome after in vitro fertilisation following Pre-implantation Genetic Diagnosis/Polymerase Chain Reaction screening for single gene disorder (sickle cell anaemia) before embryo transfer: The clinical experience of an in vitro fertilisation clinic in Nigeria  

PubMed Central

A couple, both carriers of the sickle cell anaemia trait (Genotype HbAS) with an offspring already affected with the genetic disease underwent a Pre-implantation Genetic Diagnosis/Polymerase Chain Reaction screening of biopsied blastomeres. DNA analysis of single blastomeres was carried out to find out indicated a viable intra-uterine pregnancy with embryos which carried the sickle cell mutation, which resulted in a livebirth (HbAS). PGD/PCR in combination with IVF appears to be the most suitable treatment plan for patients who are at a higher risk of reproducing offspring affected with inheritable genetic diseases.

Okeke, Chizara; Ailoje-Ibru, Kemi; Olukoya, Kemi; Ogbeche, Rose; Adewusi, Abiola; Iloabachie, Ebele; Ashiru, Oladapo

2014-01-01

393

Regulation of CCN2 gene expression and possible roles in developing tooth germs.  

PubMed

CCN proteins are extracellular and cell-associated molecules involved in several developmental processes, but their expression patterns and regulation in tooth development remain unclear. Here we first determined the expression patterns of CCN genes in mouse tooth germs. We found that at early stages CCN2 was detected in dental lamina, dental mesenchyme, and primary enamel knot, while other CCN family members were expressed broadly. By the bell stage, all members were expressed in differentiating odontoblasts and ameloblasts, but CCN1 and CCN2 transcripts were conspicuous in differentiating osteoblasts in dental follicle. Next, we asked what signalling molecules regulate CCN2 expression and what roles CCN2 may have. We found that upon surgical removal of dental epithelium CCN2 was not longer expressed in dental mesenchyme in cultured bud stage germs. Implantation of beads pre-coated with BMPs and FGFs onto E12-13 mandibular explants induced CCN2 expression in dental mesenchyme. There was a dose-dependent effect of BMP-4 on CCN2 induction; a concentration of 100 ng/?l was able to induce strong CCN2 expression while a minimum concentration of 25 ng/?l was needed to elicit appreciable expression. Importantly, Noggin treatment inhibited endogenous and BMP-induced CCN2 expression, verifying that CCN2 expression in developing tooth germs requires BMP signalling. Lastly, we found that rCCN2 stimulated proliferation in dental mesenchyme in a dose-dependent manner. Together, the data indicate that expression of CCN genes is spatio-temporally regulated in developing tooth germs. CCN2 expression appears to depend on epithelial and mesenchymal-derived signalling factors, and CCN2 can elicit strong proliferation in dental mesenchyme. PMID:24112732

Kanyama, Manabu; Shimo, Tsuyoshi; Sugito, Hiroki; Nagayama, Motohiko; Kuboki, Takuo; Pacifici, Maurizio; Koyama, Eiki

2013-11-01

394

Hydrogen Implants for Layer Exfoliation  

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

395

Tooth configuration for an earth boring bit  

SciTech Connect

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

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

1985-02-19

396

New method of control of tooth whitening  

NASA Astrophysics Data System (ADS)

New methods of control of tooth bleaching stages through simultaneous measurements of a reflected light and a fluorescence signal are proposed. It is shown that the bleaching process leads to significant changes in the intensity of a scattered signal and also in the shape and intensity of the fluorescence spectra. Experimental data illustrate that the bleaching process causes essential changes in the teeth discoloration in short time as 8-10 min from the beginning of the application procedure. The continuation of the treatment is not necessary moreover the probability of the enamel destroy increases considerably. The proposed optical back control of tooth surface is a base for development of a practical set up to control the duration of the bleaching procedure.

Angelov, I.; Mantareva, V.; Gisbrecht, A.; Valkanov, S.; Uzunov, Tz.

2010-10-01

397

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

Microsoft Academic Search

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

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

2008-01-01

398

Peri-implant health around screw-shaped c.p. titanium machined implants in partially edentulous patients with or without ongoing periodontitis.  

PubMed

The relationship between periodontitis and peri-implantitis remains a matter of debate. The present study compared, "within" randomly chosen partially edentulous patients (n=84 subjects, 97 jaws), the marginal bone loss around teeth and implants during 5 years (range 3 to 11 years) following the first year of bone remodelling. The patients had all been rehabilitated by means of screw-shape c.p. titanium implants with a machined surface (Brånemark system). During the 5 years observation interval, periodontal parameters (marginal bone and attachment loss, the latter for teeth only) were collected together with data on confounding factors (smoking, oral hygiene, tooth loss). Marginal bone loss was measured through long-cone intra-oral radiographs. The mean "interval" bone loss was significantly (P=0.0001) higher around teeth (0.48+/-0.95 mm) than around implants (0.09+/-0.28 mm). The corresponding data for the "worst" performing tooth (0.99+/-1.25 mm) and implant (0.19+/-0.32 mm) per subject showed the same tendency. Neither attachment nor bone loss around teeth correlated with marginal bone loss around implants. This study indicated that the rate of bone loss around screw-shape c.p. titanium implants with a machined surface (Brånemark system implants) was not influenced by the progression rate of periodontal destruction around the remaining teeth within the same jaw. PMID:11737102

Quirynen, M; Peeters, W; Naert, I; Coucke, W; van Steenberghe, D

2001-12-01

399

Functional Tooth Regeneration Using a Bioengineered Tooth Unit as a Mature Organ Replacement Regenerative Therapy  

PubMed Central

Donor organ transplantation is currently an essential therapeutic approach to the replacement of a dysfunctional organ as a result of disease, injury or aging in vivo. Recent progress in the area of regenerative therapy has the potential to lead to bioengineered mature organ replacement in the future. In this proof of concept study, we here report a further development in this regard in which a bioengineered tooth unit comprising mature tooth, periodontal ligament and alveolar bone, was successfully transplanted into a properly-sized bony hole in the alveolar bone through bone integration by recipient bone remodeling in a murine transplantation model system. The bioengineered tooth unit restored enough the alveolar bone in a vertical direction into an extensive bone defect of murine lower jaw. Engrafted bioengineered tooth displayed physiological tooth functions such as mastication, periodontal ligament function for bone remodeling and responsiveness to noxious stimulations. This study thus represents a substantial advance and demonstrates the real potential for bioengineered mature organ replacement as a next generation regenerative therapy.

Imamura, Aya; Ogawa, Miho; Yasukawa, Masato; Yamazaki, Hiromichi; Morita, Ritsuko; Ikeda, Etsuko; Nakao, Kazuhisa; Takano-Yamamoto, Teruko; Kasugai, Shohei; Saito, Masahiro; Tsuji, Takashi

2011-01-01

400

A report of an impacted primary maxillary central incisor tooth.  

PubMed

Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5-year-old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony-like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or 'dens in dente'. Subsequently, enameloplasty and composite resin build-up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs. PMID:23305157

Anthonappa, Robert P; Ongtengco, Kristine L; King, Nigel M

2013-10-01

401

Cochlear Implants  

MedlinePLUS

... portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts: A microphone, which picks up sound from the environment. A speech processor, which selects and arranges sounds ...

402

[Dental implantations of ceramics-coated metals].  

PubMed

Recent studies and personal experience of the Authors in the field of dental implants have encountered the same fundamental problem which arises with orthopedic prosthesis procedures. The basic problem is that of adhesion between the bone tissue and the metal implant. Chrome-cobalt alloy, Tantalum and Titanium are the metals of most recent use. The Authors therefore proceeded to investigate the behaviour of alveolar bone tissue in the proximity of artificial teeth made of alloy (platinum-gold) covered with ceramic, as used in prosthetic dentistry. The experiment was carried out in a dog and a man. In the dog, two of its mandibular teeth were substituted with the same ceramic-gold implants: the first, a replica of natural tooth, was placed in the socket and held in place by metal splint and mandibular circumferential wirings. The other implant, without a replicated crown, was left free, within the alveolus, without contacting the near or opposing teeth. A solid smooth surfaced alumina device, shaped like a small cylinder, was implanted in the upper femoral epiphysis of the same animal. PMID:1105133

Cini, L; Gasparini, F; Michieli, S; Pizzoferrato, A; Sandrolini-Cortesi, S

1975-01-01

403

Orthodontic Tooth Movement with Clear Aligners  

PubMed Central

Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5?mm. every two weeks using clear aligners. A duplicate aligner was provided for the second week of each cycle. Weekly polyvinyl siloxane (PVS) impressions were taken, and digital models were fabricated to measure OTM. Initial and final cone beam computed tomography (CBCT) images were obtained to characterize OTM. Results were compared to data from a similar protocol, where subjects received a new aligner biweekly. No significant difference was found in the amount of OTM between the two groups, with mean total OTM of 1.11?mm. (standard deviation (SD) 0.30) and 1.07?mm. (SD 0.33) for the weekly aligner and biweekly control groups, respectively (P = 0.72). Over eight weeks, in two-week intervals, material fatigue does not play a significant role in the rate or amount of tooth movement.

Drake, Carl T.; McGorray, Susan P.; Dolce, Calogero; Nair, Madhu; Wheeler, Timothy T.

2012-01-01

404

Developmental biology and building a tooth.  

PubMed

During the last 15 years, we have started to understand tooth development at the gene level. The list of genes known to regulate the position, shape, or number of teeth is lengthening rapidly. Interestingly, so far all these genes have important functions in the mediation of cell communication, which is generally considered the most important mechanism driving embryonic development. The communication is mediated by small signal molecules that are sent to nearby cells, thereby affecting their behavior and advancing differentiation. There are dozens of different signals and their receptors and target genes, which together form complicated signaling networks. The defects in several human conditions affecting tooth development have been identified recently, and these genes have turned out to be necessary components of signaling networks. Experimental studies using transgenic mice as models for human syndromes such as ectodermal and cleidocranial dysplasia have pinpointed the exact roles of the disease genes and indicated ways for possible new therapies. It is also possible that by combining the knowledge of molecular regulation of tooth development with the recent breakthroughs in stem cell research, dreams of building new teeth in dental practice may come true in the future. PMID:14620213

Thesleff, Irma

2003-09-01

405

Ridge Preservation for Implant Therapy: a Review of the Literature  

PubMed Central

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

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

2014-01-01

406

Influence of tooth profile modification on spur gear dynamic tooth strain  

NASA Technical Reports Server (NTRS)

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.

Oswald, Fred B.; Townsend, Dennis P.

1995-01-01

407

Simulated Single Tooth Bending of High Temperature Alloys.  

National Technical Information Service (NTIS)

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 rotationa...

C. Burke R. F. Handschuh

2012-01-01

408

Clinical research in implant dentistry: evaluation of implant-supported restorations, aesthetic and patient-reported outcomes.  

PubMed

The articles discussed in working group 3 dealt with specific aspects of clinical research. In this context, the literature reporting on survival and complication rates of implant-supported or implant-tooth supported restorations in longitudinal studies of at least 5 years were discussed. The second aspect dealt with the evaluation of aesthetic outcomes in clinical studies and the related index systems available. Finally, the third aspect discussed dealt with patient-reported outcome measures (PROMs). A detailed appraisal of the available methodology was presented. PMID:22533953

Lang, Niklaus P; Zitzmann, Nicola U

2012-02-01

409

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

PubMed

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

Kalarickal, Biju

2014-05-01

410

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

PubMed Central

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

2014-01-01

411

A clinical report on the 18-month cumulative survival rates of implants and implant prostheses with an internal connection implant system.  

PubMed

Titanium implants have been successful in both dentulous and edentulous patients. The original Brånemark titanium implants were introduced with external hex connections between implants and abutments. Successes and failures/complications with both the biology and mechanics of this connection system have been reported. In an attempt to improve the predictability and success of implant/abutment connections, internal connections between implants and abutments were developed significantly differently from external implant/abutment connections in terms of size, surface area, and geometry. Forty-five consecutive partially edentulous patients were treated with 83 implants (Osseotite Certaina). The implants were allowed to heal for at least 8 weeks without occlusal loading. All were restored with single, nonsplinted restorations. The implants were loaded with fully functional occlusions for at least 1 year. Recall appointments were scheduled at 1, 6, 12, 18, 24, and 36 months after implant placement. Eighty-two of the 83 implants were clinically stable and considered to be osseointegrated 18 months after occlusal loading for a cumulative survival rate (CSR) (implants) of 100%. All of the abutment screws and restorations were non-mobile 18 months after occlusal loading for a CSR (prostheses) of 100%. This internal implant/abutment connection was clinically successful and should benefit restorative dentists involved in implant dentistry by decreasing the number of maintenance visits and problems associated with dental implant treatment. PMID:16646396

Drago, Carl J; O'Connor, C Garry

2006-04-01

412

Tooth structural health monitoring with a fiber optic microbend sensor  

NASA Astrophysics Data System (ADS)

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.

Kishen, A.; Rafique, A.

2006-03-01

413

Apparatus and method for treating infected tooth using ionophoresis  

US Patent & Trademark Office Database

Apparatus and method for treating a tooth infected by a pathogen. The apparatus comprises at least one adjustable electric voltage generator for generating an direct current, an applicator device having a first pole and a second pole, the first pole being formed as a needle so as to penetrate into a canal of the infected tooth and the second pole being brought into direct contact with a zone of a body of a patient having the infected tooth and an electric circuit for maintaining the direct current constant while an impedance of the at least one adjustable electric voltage generator varies, the impedance being determined by the zone of the body of the patient where the direct current passes. The method for treating a tooth infected by a pathogen comprises applying an direct current into a canal of the infected tooth and maintaining the direct current constant during a duration of an application of the direct current to the infected tooth.

2002-09-03

414

Implant Chips  

NSDL National Science Digital Library

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

Schroeder, Ted.

2002-01-01

415

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

416

A review of the safety of tooth bleaching.  

PubMed

This article considers the safety of tooth bleaching based on a Medline search of clinical, animal and in vitro studies between 1986 and 2007. Clinical Relevance: Bleaching is the least invasive option for improving tooth colour compared to alternatives such as crowns and veneers. However, no dental procedure is without risk and the clinician should be aware of the safety issues and adverse effects of tooth bleaching so that patients can be fully informed. PMID:20166376

Burrows, Stephen

2009-12-01

417

3-D finite element simulation for ultrasonic propagation in tooth  

Microsoft Academic Search

ObjectivesUltrasonic testing of the tooth has been suggested as an alternative method of identifying dental pathology. Due to the complex geometry and low transmission efficiency of ultrasonic signals in tooth structures, it is difficult to establish one-to-one correspondence between ultrasonic behaviour and specific tooth pathologies both in vitro and in vivo. In order to facilitate ultrasonic diagnosis in dental applications,

Xiaoqing Sun; Erich A. Witzel; Hongxin Bian; Shaoying Kang

2008-01-01

418

Computer aided design of bevel gear tooth surfaces  

NASA Technical Reports Server (NTRS)

This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

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

1989-01-01

419

Tooth positioners and their effects on treatment outcome  

PubMed Central

Malocclusion can also be corrected by means of clear removable appliances called as “tooth positioners” or “aligners”. A tooth positioner is used to control settling and to minimize or eliminate relapse of the teeth after an orthodontic treatment. In this article, a complete review of the objectives, course of treatment, fabrication, and the materials used for fabrication of tooth positioners along with their importance and disadvantages were discussed. Tooth positioners did improve the overall orthodontic treatment outcome as quantified by the ABO (American Board of orthodontics) objective scoring method. But once the initial occlusal contact was achieved, the vertical movement of teeth was found to be inhibited.

Pravindevaprasad, A.; Therese, Beena Agnes

2013-01-01

420

Tooth regeneration from newly established cell lines from a molar tooth germ epithelium  

Microsoft Academic Search

In order to investigate tooth development, several cell lines of the dental epithelium and ectomesenchyme have been established. However, no attempt has been reported to regenerate teeth with cell lines. Here, we have established several clonal cell lines of the dental epithelium from a p53-deficient fetal mouse. They expressed specific markers of the dental epithelium such as ameloblastin and amelogenin.

Akihiko Komine; Momoko Suenaga; Kazuhisa Nakao; Takashi Tsuji; Yasuhiro Tomooka

2007-01-01

421

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

422

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

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

2014-04-01

423

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

424

21 CFR 872.3910 - Backing and facing for an artificial tooth.  

Code of Federal Regulations, 2010 CFR

... Backing and facing for an artificial tooth. 872.3910 Section 872.3910 ...Backing and facing for an artificial tooth. (a) Identification. A backing and facing for an artificial tooth is a device intended for use in...

2012-04-01

425

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2010 CFR

... false Bracket adhesive resin and tooth conditioner. 872.3750 Section...872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a device composed...

2012-04-01

426

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

Code of Federal Regulations, 2010 CFR

...2012-04-01 false Posterior artificial tooth with a metal insert. 872.3900 ...§ 872.3900 Posterior artificial tooth with a metal insert. (a) Identification. A posterior artificial tooth with a metal insert is a...

2012-04-01

427

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Bracket adhesive resin and tooth conditioner. 872...872.3750 Bracket adhesive resin and tooth conditioner. ...Identification. A bracket adhesive resin and tooth conditioner is a...polymethylmethacrylate, intended to cement an orthodontic bracket to...

2010-04-01