Biologically Based Restorative Management of Tooth Wear

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Martin G. D. Kelleher

2012-01-01

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

Tooth-bleaching procedures and their controversial effects: A literature review

Science.gov (United States)

Alqahtani, Mohammed Q.

2014-01-01

Aim This review article will help clinicians improve their understanding of the history of bleaching procedures, bleaching types, components, mechanisms, and their effects on soft tissue, tooth structures, resin composite, and bonding. Methods The controversial issues about bleaching procedures and their effects are reviewed. Additionally, the consequences of pre- and post-bleaching on the bonding potential of composite resin restorations to tooth structure are discussed. Conclusion The overall goal of the paper is to help reduce risks for patients. PMID:25408594

Minimum intervention dentistry and the management of tooth wear in general practice.

Science.gov (United States)

Meyers, I A

2013-06-01

The incidence of tooth wear, or non-carious tooth surface loss (NCTSL), is increasing and oral rehabilitation of patients with non-carious tooth loss requires strategies that address all the factors relevant to the aetiology and pathogenesis of the condition. The multifactorial nature of tooth wear and the variability in its clinical presentation provides treatment challenges for the clinician and successful management must be more than just restoration. Management must include an appropriate mix of preventive and restorative strategies and an understanding that long-term restorative success is affected by the patient's oral environment, and how diet, lifestyle and medical status can modify this environment. Ultimately, the success of any restorative intervention is very dependent on the stability of the oral environment and the condition of the remaining tooth structure. Minimum intervention dentistry (MID) philosophies are ideally suited to tooth wear cases and an overall MID strategy involving diagnosis, recognition and control of predisposing factors, stabilization of the oral environment, remineralization and restoration of the tooth structure, and ongoing maintenance can be implemented. When restorative treatment is required, contemporary materials and techniques are available that can provide cost-effective and conservative restorative alternatives for patients unable to undergo the complex indirect restorative techniques that are both costly and time consuming to implement. These minimally invasive approaches are not only an economically viable solution, but can provide aesthetic and functional rehabilitation and maintain tooth structure as a precursor to more complex restorative options when required. © 2013 Australian Dental Association.

Reasons for placement of restorations on previously unrestored tooth surfaces by dentists in The Dental Practice-Based Research Network

DEFF Research Database (Denmark)

Nascimento, Marcelle M; Gordan, Valeria V; Qvist, Vibeke

2010-01-01

The authors conducted a study to identify and quantify the reasons used by dentists in The Dental Practice-Based Research Network (DPBRN) for placing restorations on unrestored permanent tooth surfaces and the dental materials they used in doing so....

[An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

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Wei, Xue; Li, Yan

2009-12-01

To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

Effects of delayed finishing/polishing on surface roughness, hardness and gloss of tooth-coloured restorative materials.

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Yazici, A Ruya; Tuncer, Duygu; Antonson, Sibel; Onen, Alev; Kilinc, Evren

2010-01-01

The aim of this study was to investigate the effect of delayed finishing/polishing on the surface roughness, hardness and gloss of tooth-coloured restorative materials. Four different tooth-coloured restoratives: a flowable resin composite- Tetric Flow, a hybrid resin composite- Venus, a nanohybrid resin composite- Grandio, and a polyacid modified resin composite- Dyract Extra were used. 30 specimens were made for each material and randomly assigned into three groups. The first group was finished/polished immediately and the second group was finished/polished after 24 hours. The remaining 10 specimens served as control. The surface roughness of each sample was recorded using a laser profilometer. Gloss measurements were performed using a small-area glossmeter. Vickers microhardness measurements were performed from three locations on each specimen surface under 100g load and 10s dwell time. Data for surface roughness and hardness were analyzed by Kruskal Wallis test and data for gloss were subjected to one-way ANOVA and Tukey test (P gloss values were recorded under Mylar strip for all materials. While delayed finishing/polishing resulted in a significantly higher gloss compared to immediate finishing/polishing in Venus samples (P .05). The lowest hardness values were found under Mylar strip. Delayed finishing/polishing significantly increased the hardness of all materials. The effect of delayed finishing/polishing on surface roughness, gloss and hardness appears to be material dependent.

To Analyse the Erosive Potential of Commercially Available Drinks on Dental Enamel and Various Tooth Coloured Restorative Materials - An In-vitro Study.

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Karda, Babita; Jindal, Ritu; Mahajan, Sandeep; Sandhu, Sanam; Sharma, Sunila; Kaur, Rajwinder

2016-05-01

With the enormous change in life style pattern of a common man through the past few decades, there has been proportional variation in the amount and frequency of consumption of drinks. An increased consumption of these drinks will concurrently increase enamel surface roughness by demineralization, resulting in hypersensitivity and elevated caries risk. The present study was designed to evaluate the erosive potential of commercially available drinks on tooth enamel and various tooth coloured restorative materials. Extracted human teeth were taken and divided into four groups i.e. tooth enamel, glass ionomer cement, composite and compomer. Four commercially available drinks were chosen these were Coca -Cola, Nimbooz, Frooti and Yakult. The pH of each drink was measured. Each group was immersed in various experimental drinks for a period of 14 days. The erosive potential of each drink was measured by calculating the change in average surface roughness of these groups after the immersion protocol in various drinks. The data analysis was done by One Way Anova, Post-Hoc Bonferroni, and paired t -test. Group II-GIC showed highest values for mean of change in average surface roughness and the values were statistically significant (pCoca-cola showed the highest erosive potential and Yakult showed the lowest, there was no statistical significant difference between the results shown by Yakult and Frooti. Characteristics which may promote erosion of enamel and tooth coloured restorative materials were surface texture of the material and pH of the drinks.

Assessment of exposures and potential risks to the US adult population from wear (attrition and abrasion) of gold and ceramic dental restorations.

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Richardson, G Mark; Clemow, Scott R; Peters, Rachel E; James, Kyle J; Siciliano, Steven D

2016-01-01

Little has been published on the chemical exposures and risks of dental restorative materials other than from dental amalgam and composite resins. Here we provide the first exposure and risk assessment for gold (Au) alloy and ceramic restorative materials. Based on the 2001-2004 US National Health and Nutrition Examination Survey (NHANES), we assessed the exposure of US adults to the components of Au alloy and ceramic dental restorations owing to dental material wear. Silver (Ag) is the most problematic component of Au alloy restorations, owing to a combination of toxicity and proportional composition. It was estimated that adults could possess an average of four tooth surfaces restored with Au alloy before exceeding, on average, the reference exposure level (REL) for Ag. Lithium (Li) is the most problematic component of dental ceramics. It was estimated that adults could possess an average of 15 tooth surfaces restored with ceramics before exceeding the REL for Li. Relative risks of chemical exposures from dental materials decrease in the following order: Amalgam>Au alloys>ceramics>composite resins.

Long-term observation of endodontic surgical intervention to treat root perforation and apical periodontitis: a case report of an amalgam-restored tooth.

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Tsurumachi, Tamotsu; Hayashi, Makoto

2003-10-01

A case of crestal root perforation and periapical lesion in a maxillary left lateral incisor is reported. Teeth with root perforation present technical difficulties in their clinical management because of their complex defects. In the present case, surgical endodontic treatment was chosen. The apical and lateral pathology was curetted, the tooth root was resected, and a retrograde root restoration of amalgam was placed in a root-end cavity and perforation site. A 10-year follow-up clinical and radiographic examination showed an asymptomatic tooth with osseous healing proceeding.

Components of patient satisfaction with a dental restorative visit

DEFF Research Database (Denmark)

Riley, Joseph L; Gordan, Valeria V; Rindal, D Brad

2012-01-01

The authors conducted a study to identify components of patient satisfaction with restorative dental care and to test the hypothesis that certain dentist, patient and procedure factors are associated with patient satisfaction.......The authors conducted a study to identify components of patient satisfaction with restorative dental care and to test the hypothesis that certain dentist, patient and procedure factors are associated with patient satisfaction....

Tooth whitening: what we now know.

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Carey, Clifton M

2014-06-01

Current research about tooth whitening shows that it is safe and effective when manufacturer's protocol is followed, yet there are risks of which the profession and users should be aware. This update provides a summary of current research and assessment of the safety and efficacy of tooth whitening regimens. Tooth whitening has become one of the most frequently requested dental procedures by the public. The public has come to demand whiter, more perfect smiles and in response many choices for tooth whitening have been made available. These include home-based products such as toothpastes, gels, and films, as well as in-office based systems where products containing highly concentrated bleaching agents are applied under professional supervision. The profession and public have been aware of certain risks related to tooth whitening such as increased tooth sensitivity and gingival irritation. New research has shown that there are other risks such as tooth surface roughening and softening, increased potential for demineralization, degradation of dental restorations, and unacceptable color change of dental restorations. The new research is also focused on optimizing whitening procedures to reduce tooth sensitivity and to increase the persistence of the whitening. Current reports in the literature are reviewed that are related to the use of peroxide based whitening methods. These reports include in vitro studies for method optimization and mechanism as well as clinical studies on effects of various whitening regimens. When manufacturer's instructions are followed, hydrogen peroxide and carbamide peroxide based tooth whitening is safe and effective. Patients should be informed of the risks associated with tooth whitening and instructed on identification of adverse occurrences so that they may seek professional help as needed. Copyright © 2014 Elsevier Inc. All rights reserved.

Periodontal and restorative considerations with clear aligner treatment to establish a more favorable restorative environment.

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Boyd, Robert L

2009-06-01

Although standard fixed appliances are better suited to control difficult tooth movement in three planes of space, clear aligner orthodontic treatment may be requested by patients because of the superior esthetics compared with conventional fixed appliances when clear aligners can be considered. Several clinical trials have shown improved periodontal status during orthodontic treatment with clear aligners while fixed appliances have almost always been associated with increased inflammation and mild periodontal breakdown despite preventive measures performed during treatment. There have been no reports of decalcification and only one reported case of root resorption with clear aligners, whereas with fixed appliances, numerous incidents of both decalcification and root resorption have been reported. In addition, studies have also shown significantly less pain from soft-tissue injuries and muscle soreness from parafunctional habits with computer-aided clear aligners. Restorative advantages include improved esthetics and comfort during treatment for better case acceptance and the ability to bleach teeth throughout treatment. Improving tooth alignment with orthodontic treatment with fixed or clear appliances increases the clinician's potential capability to perform more conservative restorative procedures, requiring less tooth structure removal and less endodontic involvement because of better tooth positions. In those cases in which clear aligner appliances may be appropriate, less damage may occur to existing porcelain restorations than might transpire from bonding of fixed appliances and their removal, as well as potentially reduced tooth wear during treatment. This article presents three case reports that demonstrate the periodontal and restorative aspects of treatment using the computer-aided clear appliances, which have either eliminated the need for certain restorative procedures or created a better periodontal and tooth position environment for performing these

Evaluation of autogenous tooth transplantation for replacement of the missing or unrestorable mandibular molar tooth

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Wahiduj Jaman

2017-06-01

Full Text Available This study was undertaken to evaluate the functional and occlusal stability of autogenous tooth transplantation. A total of 30 patients were included. Among them, 21 participants received transplanted first molar and the remaining 9 received transplanted second molar. In all the cases, donor tooth were third molar. In each participant, extraction of un-restorable first or second molar tooth was performed which was then replaced by atrumatic extracted third molar tooth. Each third molar tooth was placed in the recipient extracted socket, followed by the evaluation of the occlusion and then stabilized with arch bar and ligature wire. Clinical follow-up evaluation was performed at 15 days, 3 and 12 months in respect to occlusal stability, tooth mobility and periodontal status. It was found that 23 transplanted tooth were successful and the remaining 7 tooth need long-term observation for the final outcome, which was statistically significant. It can be concluded that the autogenous tooth transplantation can replace missing tooth to ensure the preservation of function, aesthetic and to prevent bone resorption of the missing area of the jaw, which can lead to exceptional esthetic and functional outcome.

Clinician assessments and patient perspectives of single-tooth implant restorations in the esthetic zone of the maxilla: A systematic review.

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Arunyanak, Sirikarn P; Pollini, Adrien; Ntounis, Athanasios; Morton, Dean

2017-07-01

Esthetic outcomes associated with implant dentistry are important to both clinicians and patients. However, esthetic satisfaction may vary between the 2 groups. In order to evaluate the current publications relating to this topic, the following focused question was developed, "what are the quantitative and qualitative differences between clinician evaluations and patient perspectives in the assessment of single-tooth implant outcomes in the esthetic zone?" The purpose of this systematic review was to identify differences in esthetic satisfaction between clinicians and patients when evaluating single-tooth implant-supported restorations. An electronic search of the Medline database and Cochrane Central Register of Controlled Trials (2000 to 2014) was performed. The search was supplemented by a manual search of specific journals. A quality assessment of full-text articles was performed according to Cochrane Collaboration's tool and Newcastle-Ottawa scale for risk of bias assessment. Information regarding outcomes was collected and compared. The search term combinations identified 555 titles. Subsequent to further review, 11 publications, including 2 randomized controlled trials, were selected for inclusion. Because of the heterogeneity of the study designs, study interventions, and esthetic assessment methods, no meta-analysis was performed. The clinicians identified a satisfactory outcome in 51% to 100% for peri-implant soft tissue and 62% to 90% for implant restorations. Patients showed a mean range score of 43% to 93% for peri-implant soft tissue and 81% to 96% for implant restorations. The visual analog scale score of the dentists was always lower than that of the patients. The review identified correlations between subjective and objective assessments for the Pink Esthetic Score (PES), the Papilla Index (PI), the Implant Crown Aesthetic Index (ICAI), and the modified (mod-ICAI) indices. Clinicians are more critical of esthetic outcomes than patients. The PES and

Graded changes in enamel component volumes resulted from a short tooth bleaching procedure.

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Ferreira, Artemisa Fernanda Moura; Perez, Flávia Maria de Moraes Ramos; Limeira Júnior, Francisco de Assis; de Moura, Mirella de Fátima Liberato; de Sousa, Frederico Barbosa

2016-05-01

To test the hypothesis that changes in enamel component volumes (mineral, organic, and water volumes, and permeability) are graded from outer to inner enamel after a short bleaching procedure. Extracted unerupted human third molars had half of their crowns bleached (single bleaching session, 3 × 15 min), and tooth shade changes in bleached parts were analyzed with a spectrophotometer. Ground sections were prepared, component volumes and permeability were quantified at histological points located at varying distances from the enamel surface (n=10 points/location), representing conditions before and after bleaching. Tooth shade changes were significant (pbleaching, except at the outer layers. Multiple analysis of covariances revealed that most of the variance of the change in enamel composition after bleaching was explained by the combination of the set of types of component volume (in decreasing order of relevance: mineral loss, organic gain, water gain, and decrease in permeability) with the set of distances from the enamel surface (graded from the enamel surface inward) (canonical R(2)=0.97; p99%). Changes in enamel composition after a short bleaching procedure followed a gradient within component volumes (mineral loss>organic gain>water gain>decrease in permeability) and decreased from the enamel surface inward. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tooth Retained Implant: No More an Oxymoron

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Divya Bhat

2011-03-01

Full Text Available Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1 Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2 Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dam-pen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration.Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

Restoration of traumatized teeth with resin composites

DEFF Research Database (Denmark)

Pallesen, Ulla; van Dijken, Jan WV

2018-01-01

For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth...... present an aesthetic problem due to exposure of un-aesthetic crown-margins. The invasive permanent crown restorations are therefore often not suc-cessful on a long-term scale. On the other hand, a conservative direct restoration of an extensively fractured incisor crown with resin composite may......-structure and with minimal risk of pulpal complication. In addition, it offers an aesthetic solution to the patient immediately after an injury, which may bring a little comfort in a sad situation. The resin composite build-up is often changed or repaired a couple of times, before the tooth is restored with a porcelain...

A Comprehensive Mixture of Tobacco Smoke Components Retards Orthodontic Tooth Movement via the Inhibition of Osteoclastogenesis in a Rat Model

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Maya Nagaie

2014-10-01

Full Text Available Tobacco smoke is a complex mixture of numerous components. Nevertheless, most experiments have examined the effects of individual chemicals in tobacco smoke. The comprehensive effects of components on tooth movement and bone resorption remain unexplored. Here, we have shown that a comprehensive mixture of tobacco smoke components (TSCs attenuated bone resorption through osteoclastogenesis inhibition, thereby retarding experimental tooth movement in a rat model. An elastic power chain (PC inserted between the first and second maxillary molars robustly yielded experimental tooth movement within 10 days. TSC administration effectively retarded tooth movement since day 4. Histological evaluation disclosed that tooth movement induced bone resorption at two sites: in the bone marrow and the peripheral bone near the root. TSC administration significantly reduced the number of tartrate-resistant acid phosphatase (TRAP-positive osteoclastic cells in the bone marrow cavity of the PC-treated dentition. An in vitro study indicated that the inhibitory effects of TSCs on osteoclastogenesis seemed directed more toward preosteoclasts than osteoblasts. These results indicate that the comprehensive mixture of TSCs might be a useful tool for detailed verification of the adverse effects of tobacco smoke, possibly contributing to the development of reliable treatments in various fields associated with bone resorption.

ENDODONTIC TREATMENT AND POST-CORE RESTORATION

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Evi Hafifah

2006-04-01

Full Text Available Endodontic root canal treatment is to maintain the tooth as long as possible in the arch’s width in a good functional status. In order to reach that goal, all irritation to the pulp should be eliminated so that the tooth has a healthy periodontal tissue support. A female patient, aged 37 years, came for her upper front tooth which had been restored with a pin crown a year ago. One month ago she had a swelling accompanied with throbbing pain. There was no history of general diseases and her oral hygiene was good. Clinically 11 was restored with a pin crown and the radiographic picture showed a narrow pulp chamber, normal roots with normal canals, thickened periodontium, broken laminar dura, and diffuse periapical rarefaction. The tooth was diagnosed with pulpal necrosis. A conventional root canal treatment was performed followed by the insertion of a post core crown. The result showed a satisfactory treatment plan, a good restoration, successful treatment in this case was due to the role of the dentist to create healthy soft and hard tissues in the oral cavity before restoration, and also due to patient cooperation.

An interdisciplinary approach to treat crown‑root‑fractured tooth ...

African Journals Online (AJOL)

Restoration of a crown‑root subgingival fractured tooth, especially at anterior aesthetic zones is still a great challenge for restorative dentists. Crown lengthening procedure alone has the disadvantage of high gingival curve of the final restoration, which was not discontinuous to adjacent teeth and thus compromise cosmetic ...

Survival Rates from Fracture of Endodontically Treated Premolars Restored with Full-coverage Crowns or Direct Resin Composite Restorations: A Retrospective Study.

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Suksaphar, Warattama; Banomyong, Danuchit; Jirathanyanatt, Titalee; Ngoenwiwatkul, Yaowaluk

2018-02-01

The aim of the present study was to compare the survival rates against fracture of premolar endodontically treated teeth (ETT) restored with resin composite or crowns and to identify risk factors associated with the fracture. Data from dental records and radiographs of premolar ETT with postendodontic restorations (ie, resin composite or crowns) were collected between 2012 and 2016 and selected following selected inclusion and exclusion criteria. Tooth location, type of restoration, number of proximal contacts, and amount of tooth surface loss were recorded. The incidence and restorability of postendodontic fractures were identified. Survival rates against fracture of the 2 restoration types were calculated using Kaplan-Meier survival analysis. Any potential factors associated with fractures were identified using Cox proportional hazards models. The survival rate against fracture of ETT restored with crowns (95.1%) was higher than resin composite (77.0%). ETT restored with resin composite with 1 or 2 tooth surface losses and 2 proximal contacts had a high survival rate of 88.5% that was not significantly different from ETT with crowns. A higher incidence of restorability after fracture was observed in teeth restored with resin composite than crowns. The type of restoration and number of proximal contacts were identified as potential risk factors associated with fracture incidence. The survival rate against fracture of ETT restored with crowns was higher than resin composite. However, ETT with 1 or 2 tooth surface losses and 2 proximal contacts and restored with resin composite showed a high survival rate that was comparable with ETT restored with crowns. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Corono-radicular biological restoration of maxillary central incisors by direct method.

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Aggarwal, Sonia; Sahoo, Sujit Ranjan; Pandharkar, Kartik

2014-11-01

This case report refers to the esthetic and functional restorations of extensively damaged maxillary central incisors with dental caries in a 32-year-old woman, with the use of posts and crowns made from natural extracted teeth. Proper restoration of such teeth with the use of natural teeth fragments are known as "biological restoration." Biological restorations can be done by using the fragments of the patients own tooth and if that is not available, tooth fragment can be obtained from an extracted tooth. These biological posts and crowns present a low cost option and an alternative technique for the morphofunctional recovery of extensively damaged teeth. There are limitations with the use of natural extracted teeth (homogenous bonding) for restoration such as the difficulty of finding teeth with a similar color and shape as that of the destroyed element, or patient may refuse to accept a tooth fragment from another patient, which prevents execution of the restoration.

Combined periodontic-orthodonticendodontic interdisciplinary approach in the treatment of periodontally compromised tooth.

Science.gov (United States)

Deepa, D; Mehta, D S; Puri, Viren K; Shetty, Sadashiva

2010-04-01

Orthodontic treatment in adult patients is one of the most frequently encountered components involving multidisciplinary approaches. In the present report, a 28-year-old male patient was treated for localized chronic periodontitis with pocket formation, mobility, pathologic migration and malalignment of maxillary left lateral incisor tooth #22. The periodontal therapy included motivation, education and oral-hygiene instructions (O.H.I.), scaling and root planing and periodontal flap surgery. Subsequently on resolution of periodontal inflammation, orthodontic therapy was carried out using the orthodontic aligner for a period of 6 months. Post-treatment (3 years) results showed complete resolution of infrabony pocket with significant bone fill, reduced tooth mobility and complete alignment of the affected maxillary left lateral incisor, thus restoring the esthetics and function.

Tooth wear

Directory of Open Access Journals (Sweden)

Tušek Ivan

2014-01-01

nanocomplexes is now available. Its use is equally effective in acidic and in neutral media. In the prevention of tooth wear, lasers (CO2, Nd:YAG and enzymes (matrix metalloproteinases are being used more frequently in modern dental practice. Depending on the degree of tooth wear, the restorative procedure, may consist of bonded composites, or glass ionomer cement restorations of tooth wear, as well as complete reconstruction of the crown (prosthetic rehabilitation in cases of severely destroyed dentition.

Challenges in reconstructing an isolated anterior tooth with a metal-free crown

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Max Doria Costa

2013-01-01

Full Text Available Introduction: Currently, new esthetic treatments are available to the dentist due to the advent of ceramic-ceramic prostheses. A new option has become part of daily clinical practice, with the promise of esthetic optimization through the elimination of metal in prosthetic crowns. The translucence of these new systems allows the transmission of light through the tooth structure, minimizing gingival darkness and producing a vibrant and natural appearance. Case Report: The patient, 30 years old, female, showed with a fractured tooth crown at the cervical level in the right lateral incisive. It was observed that the tooth had prior adequate endodontic treatment. A metal-free restorative system was selected. A plaster model was obtained for subsequent tooth preparative scanning and manufacture of ceramic framework. After receiving the framework, adjustments were made and the color choice of covering ceramic, following the protocol of choice for a chroma suboptimal aiming further characterization. After the ceramics application, adjustments in shape, texture, and occlusion were made. The crown was characterized by exterior paint, getting a favorable result, restoring esthetics and function. Discussion : The metal-free systems are a viable alternative to the restorative treatment when esthetics is desired, allowing a natural and harmonious smile, combined with the reliability of the restorative material.

Combined periodontic-orthodontic-endodontic interdisciplinary approach in the treatment of periodontally compromised tooth

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Deepa D

2010-01-01

Full Text Available Orthodontic treatment in adult patients is one of the most frequently encountered components involving multidisciplinary approaches. In the present report, a 28-year-old male patient was treated for localized chronic periodontitis with pocket formation, mobility, pathologic migration and malalignment of maxillary left lateral incisor tooth #22. The periodontal therapy included motivation, education and oral-hygiene instructions (O.H.I., scaling and root planing and periodontal flap surgery. Subsequently on resolution of periodontal inflammation, orthodontic therapy was carried out using the orthodontic aligner for a period of 6 months. Post-treatment (3 years results showed complete resolution of infrabony pocket with significant bone fill, reduced tooth mobility and complete alignment of the affected maxillary left lateral incisor, thus restoring the esthetics and function.

Unique CAD/CAM three-quarter crown restoration of a central incisor: a case report.

Science.gov (United States)

Goldberg, Marvin B; Siegel, Sharon C; Rezakani, Niloufar

2013-07-01

Computer-aided design and computer-aided manufacturing (CAD/CAM) dentistry has been in use for more than 2 decades. Recent improvements in this technology have made CAD/CAM restorations a viable alternative for routine dental care. This technology is being taught in dental schools to prepare students for contemporary dental practice and is particularly useful in unique restorative situations that allow conservation of tooth structure. This case report describes the restoration of a central incisor that was previously restored with an unesthetic three-quarter gold crown. The tooth exhibited recurrent caries and an unaffected labial wall of supported enamel. A CAD/CAM three-quarter crown was planned to conserve tooth structure. After preparation, the tooth was scanned for a CAD/CAM crown in order to fabricate a ceramic restoration, which was then milled and bonded, producing an esthetic result. Typically, in cases of esthetic enhancement, a labial laminate restoration is fabricated, but in this situation, a different approach was necessary to make a design for the lingual surface of an anterior tooth.

The dentin organic matrix - limitations of restorative dentistry hidden on the nanometer scale

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Bertassoni, Luiz E; Orgel, Joseph P.R.; Antipova, Olga; Swain, Michael V [IIT; (Sydney)

2012-07-25

The prevention and treatment of dental caries are major challenges occurring in dentistry. The foundations for modern management of this dental disease, estimated to affect 90% of adults in Western countries, rest upon the dependence of ultrafine interactions between synthetic polymeric biomaterials and nanostructured supramolecular assemblies that compose the tooth organic substrate. Research has shown, however, that this interaction imposes less than desirable long-term prospects for current resin-based dental restorations. Here we review progress in the identification of the nanostructural organization of the organic matrix of dentin, the largest component of the tooth structure, and highlight aspects relevant to understating the interaction of restorative biomaterials with the dentin substrate. We offer novel insights into the influence of the hierarchically assembled supramolecular structure of dentin collagen fibrils and their structural dependence on water molecules. Secondly, we review recent evidence for the participation of proteoglycans in composing the dentin organic network. Finally, we discuss the relation of these complexly assembled nanostructures with the protease degradative processes driving the low durability of current resin-based dental restorations. We argue in favour of the structural limitations that these complexly organized and inherently hydrated organic structures may impose on the clinical prospects of current hydrophobic and hydrolyzable dental polymers that establish ultrafine contact with the tooth substrate.

Radiopacity of 28 Composite Resins for Teeth Restorations.

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Raitz, Ricardo; Moruzzi, Patrizia Dubinskas; Vieira, Glauco; Fenyo-Pereira, Marlene

2016-02-01

Radiopacity is a fundamental requisite to check marginal adaptation of restorations. Our objective was to assess the radiopacity of 28 brands of light-cured composite resins and compare their radiopacity with that of enamel, dentin, and aluminum of equivalent thickness. Composite resin disks (0.2, 0.5, and 1 mm) were radiographed by the digital method, together with an aluminum penetrometer and a human tooth equivalent tooth section. The degree of radiopacity of each image was quantified using digital image processing. Wilcoxon nonparametric test was used for comparison of the mean thickness of each material. All of the materials tested had an equal or greater radiopacity than that of aluminum of equivalent thickness. Similar results for enamel were found with the exception of Durafill, which was less radiopaque than enamel (p composite resins comply with specification #27 of the American Dental Association. The radiopacity of Amelogen Plus, Aph, Brilhiante, Charisma, Concept Advanced, Evolux X, Exthet X, Inten S, Llis, Master Fill, Natural Look, Opallis, P60, Tetric, Tph, Z100, and Z250 was significantly higher than that of enamel (p composites, it is possible to observe the boundaries between restoration and tooth structure, thus allowing clinicians to establish the presence of microleakage or restoration gap. Suitable radiopacity is an essential requisite for good-quality esthetic restorative materials. We demonstrate that only some composites have the sufficient radiopacity to observe the boundaries between restoration and tooth structure, which is the main cause of restoration failure.

Comprehensive therapy of a fusion between a mandibular lateral incisor and supernumerary tooth: case report.

Science.gov (United States)

Onçag, Ozant; Candan, Umit; Arikan, Fatih

2005-08-01

The term fusion is used to define a developmental anomaly characterised by the union of two adjacent teeth. In the case reported here, clinical and radiographic examinations suggested a unilateral fusion between the mandibular left permanent incisor and a super-numerary tooth. Radiographs showed that the fused teeth had two distinct pulp chambers and canals. A diagnosis of chronic periapical abscess of the supernumerary tooth was made. Before root canal therapy, a periodontal surgical procedure was performed to section the central incisor and its fused supernumerary. Also, odontoplasty was performed on the roots, to establish an anatomy consistent with a normal central incisor. Later, the chronic apical abscess on the supernumerary tooth was instrumented chemo-mechanically, root canal filling was performed and an anterior composite resin restoration was placed. The patient was evaluated for one year after root canal therapy. The tooth was asymptomatic, not exhibiting any pathological root resorption or alveolar resorption, and the anterior composite restoration was intact. Instead of extracting the supernumerary tooth, the application of endodontic, periodontal, and restorative procedures proved to be an alternative treatment.

A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis

DEFF Research Database (Denmark)

Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten

2013-01-01

-tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold alloy abutments, which retained 64 all-ceramic and 34 metal-ceramic crowns. At baseline and 3-year follow......-up examinations, the biological outcome variables such as survival rate of implants, marginal bone level, modified Plaque Index (mPlI), modified Sulcus Bleeding Index (mBI) and biological complications were registered. The technical outcome variables included abutment and crown survival rate, marginal adaptation...... and PROC NLMIXED for ordinal categorical data. RESULTS: The 3-year survival rate was 100% for implants and 97% for abutments and crowns. Significantly more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040). The mPlI and mBI were not significantly different at three...

Provisional Restorations – A Permanent Problem?

Science.gov (United States)

Keys, William F; Keirby, Naomi; Ricketts, David N J

2016-12-01

Provisional restorations play an important role when providing indirect restorations. There are a number of materials and techniques available for their construction. Careful planning and construction can protect the prepared tooth surface, improve the periodontal condition and help plan for the definitive restoration. A good provisional restoration can save time, money and effort. Clinical relevance: Provisional restoration construction is an integral part of the indirect restorative process for inlays, onlays, crowns and bridges.

Tooth wear and wear investigations in dentistry.

Science.gov (United States)

Lee, A; He, L H; Lyons, K; Swain, M V

2012-03-01

Tooth wear has been recognised as a major problem in dentistry. Epidemiological studies have reported an increasing prevalence of tooth wear and general dental practitioners see a greater number of patients seeking treatment with worn dentition. Although the dental literature contains numerous publications related to management and rehabilitation of tooth wear of varying aetiologies, our understanding of the aetiology and pathogenesis of tooth wear is still limited. The wear behaviour of dental biomaterials has also been extensively researched to improve our understanding of the underlying mechanisms and for the development of restorative materials with good wear resistance. The complex nature of tooth wear indicates challenges for conducting in vitro and in vivo wear investigations and a clear correlation between in vitro and in vivo data has not been established. The objective was to critically review the peer reviewed English-language literature pertaining to prevalence and aetiology of tooth wear and wear investigations in dentistry identified through a Medline search engine combined with hand-searching of the relevant literature, covering the period between 1960 and 2011. © 2011 Blackwell Publishing Ltd.

Clinical application of single-tooth replacement with ankylos implant system

International Nuclear Information System (INIS)

Yang Xu; Liu Xue; Zhang Heng; Deng Yan; Guo Zhaozhong; Zhang Yufeng

2011-01-01

Objective: To evaluate the clinical effects of Ankylos implant system to restore the loss of single-tooth. Methods: 90 cases with loss of single-tooth were selected and treated with routinely two-stage surgery. When the patients presented with deficient alveolar ridge, guided bone regeneration (GBR), osteotome sinus floor elevation, lateral antrostomy surgery with simultaneous placement of implant were applied. They were restored with platinum ceramic crown. All the implants were followed up, and the records were kept about stability of the implant and abutment, the status of surrounding soft tissue, sealability of implant abutment junction and the marginal bone lossing through X-ray checking,and satisfaction of the patients to mastication and aspect of the restorations. The follow-up time was 1-2.5 years. Results: Among the cases,one case had peri-implant inflammation, and one case had porcelain dropped. No loosening occurred in the other implants and abuments. Implant abutment junction was sealed well. The marginal bone loss 1 year after final restoration was less than 1 mm. Soft tissue surrounding implants was healthy. The satisfaction rate was 98.9% (89/90). According to standard of implant success, 88 cases were successful, the 2.5-year cumulative success rate was 97.8%, 2 cases failed, and the failure rate was 2.2 %. Conclusion: A satisfactory treatment effects could be gotten by using Ankylos implant system to restore the loss of single-tooth. (authors)

Ten-Year Follow-Up of a Fragment Reattachment to an Anterior Tooth: A Conservative Approach.

Science.gov (United States)

Mendes, Luiz; Laxe, Laisa; Passos, Leandro

2017-01-01

This report describes the 10-year follow-up data of a patient who underwent fragment reattachment to the maxillary central incisor after coronal fracture with pulp exposure as well as the procedures followed for functional and esthetic adjustments. A 9-year-old female patient presented at the clinic of dentistry at the State University of Rio de Janeiro with a coronal fracture and pulp exposure of the right maxillary central incisor that had occurred immediately after an accident. The intact tooth fragment was recovered at the accident site and stored in milk. The treatment plan followed was to perform direct pulp capping and tooth fragment reattachment. When the patient was 14 years old, adhesion between fragment and remaining tooth was lost, and fragment reattachment was performed. Five years later, the same tooth presented clinical discoloration and absence of sensitivity during pulp vitality tests. Subsequently, a new treatment plan was formulated, which included endodontic treatment, followed by nonvital tooth bleaching and light-cured composite resin restoration. An esthetic and natural-looking restoration was achieved. Tooth fragment reattachment is not a temporary restorative technique and requires functional and esthetic adjustments over time to maintain the biomimetic characteristics of traumatized anterior teeth and predictable outcomes.

Longterm survival and reason for failure of anterior composite restoration

Directory of Open Access Journals (Sweden)

Nina Djustiana

2016-06-01

Full Text Available Composites resin restorations have been used for repairing and restoring anterior teeth for decades due to the growing needs for a cost- effective aesthetic restoration and the advancement in dental material and polymer technology. Failure of composite restorations cannot be neglected, due to multiple factors, i.e. failure to diagnose the gingival tissue, inadequate tissue management, quality of remaining tooth structure, and inadequate preparation. The aim of this review is to improve clinical performances of direct composite as permanent restorations. Long lasting aesthetic composite restorations required proper mouth preparations ,which  includes supporting and dental hard tissue preparations, tooth preparation, proper isolation, bonding procedures, light cure unit, and the resin composite itself.

RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

OpenAIRE

Yadav; Swetha

2015-01-01

Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatmen...

Restorative Rehabilitation of a Patient with Dental Erosion.

Science.gov (United States)

AlShahrani, Mohammed Thamer; Haralur, Satheesh B; Alqarni, Mohammed

2017-01-01

Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clinical report describes an adult patient with gastroesophageal reflux induced dental erosion involving the palatal surface of the maxillary anterior teeth. The extensive involvement of the palatal surfaces compromised the esthetics, incisal guidance, and functional occlusal efficiency. Indirect all-ceramic restorations were utilized to restore the esthetics and occlusal reconstruction. In conclusion, patients affected by severe dental erosion require prosthetic rehabilitation besides the management of the associated medical condition.

Restorative Rehabilitation of a Patient with Dental Erosion

Directory of Open Access Journals (Sweden)

Mohammed Thamer AlShahrani

2017-01-01

Full Text Available Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clinical report describes an adult patient with gastroesophageal reflux induced dental erosion involving the palatal surface of the maxillary anterior teeth. The extensive involvement of the palatal surfaces compromised the esthetics, incisal guidance, and functional occlusal efficiency. Indirect all-ceramic restorations were utilized to restore the esthetics and occlusal reconstruction. In conclusion, patients affected by severe dental erosion require prosthetic rehabilitation besides the management of the associated medical condition.

Direct composite restoration of permanent anterior teeth uncomplicated crown fractures

Directory of Open Access Journals (Sweden)

Ashley Evans Nicholas

2018-01-01

Full Text Available An uncomplicated crown fracture is a fracture that involves only the tooth enamel or the dentin and tooth enamel without any damage or exposure to the pulp. Crown fracture of the anterior teeth usually caused by traumatic forces such as falls, accidents, violence, or sports activities. Traumatic injuries of the oral region frequently involve the anterior teeth, especially maxillary incisors due to the anatomic factors which may affect the functional and aesthetical values of the teeth. The objective of this literature study was to know more about uncomplicated crown fracture of the anterior teeth and its restoration. This research was a literature study performed by researching, highlighting various interesting facts and compiling the relevant published journals. The most common and ideal direct restoration of the anterior teeth was the composite resin restoration. The anterior teeth restoration was considered to be a complex and challenging case to solves due to the fact that besides reconstructing the tooth and regaining the function, the aesthetical aspect was also becoming the main objectives. The permanent anterior teeth uncomplicated crown fracture was the most common case of tooth fractures which was mainly caused by traumatic injuries such as falls, accidents, excessive forces, violence, and also sports activities. Dental injuries of the anterior teeth also affected the aesthetical properties and the function of the tooth. Composite resin restoration was able to performed directly on the permanent anterior teeth uncomplicated crown fracture.

Effect of restoration volume on stresses in a mandibular molar: a finite element study.

Science.gov (United States)

Wayne, Jennifer S; Chande, Ruchi; Porter, H Christian; Janus, Charles

2014-10-01

There can be significant disagreement among dentists when planning treatment for a tooth with a failing medium-to-large--sized restoration. The clinician must determine whether the restoration should be replaced or treated with a crown, which covers and protects the remaining weakened tooth structure during function. The purpose of this study was to evaluate the stresses generated in different sized amalgam restorations via a computational modeling approach and reveal whether a predictable pattern emerges. A computer tomography scan was performed of an extracted mandibular first molar, and the resulting images were imported into a medical imaging software package for tissue segmentation. The software was used to separate the enamel, dentin, and pulp cavity through density thresholding and surface rendering. These tissue structures then were imported into 3-dimensional computer-aided design software in which material properties appropriate to the tissues in the model were assigned. A static finite element analysis was conducted to investigate the stresses that result from normal occlusal forces. Five models were analyzed, 1 with no restoration and 4 with increasingly larger restoration volume proportions: a normal-sized tooth, a small-sized restoration, 2 medium-sized restorations, and 1 large restoration as determined from bitewing radiographs and occlusal surface digital photographs. The resulting von Mises stresses for dentin-enamel of the loaded portion of the tooth grew progressively greater as the size of the restoration increased. The average stress in the normal, unrestored tooth was 4.13 MPa, whereas the smallest restoration size increased this stress to 5.52 MPa. The largest restoration had a dentin-enamel stress of 6.47 MPa. A linear correlation existed between restoration size and dentin-enamel stress, with an R(2) of 0.97. A larger restoration volume proportion resulted in higher dentin-enamel stresses under static loading. A comparison of the von Mises

Restoring proximal caries lesions conservatively with tunnel restorations.

Science.gov (United States)

Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

2013-07-30

The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations.

Measurement of opalescence of tooth enamel.

Science.gov (United States)

Lee, Yong-Keun; Yu, Bin

2007-08-01

Opalescent dental esthetic restoratives look natural and esthetic in any light, react to light in the same manner as the natural tooth and show improved masking effect. The objective of this study was to determine the opalescence of tooth enamel with reflection spectrophotometers. Color of intact bovine and human enamel was measured in the reflectance and transmittance modes. Two kinds of spectrophotometers were used for bovine and one kind was used for human enamel. The opalescence parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Deltab(*)) and red-green color coordinate (CIE Deltaa(*)) between the reflected and transmitted colors. Mean OP value of bovine enamel was 10.6 (+/-1.4) to 19.0 (+/-2.1), and varied by the configuration of spectrophotometers. Mean OP value of human enamel was 22.9 (+/-1.9). Opalescence varied by the configuration of measuring spectrophotometer and the species of enamel. These values could be used in the development of esthetic restorative materials.

Smile restoration through use of enamel microabrasion associated with tooth bleaching.

Science.gov (United States)

Sundfeld, Renato Herman; Rahal, Vanessa; de Alexandre, Rodrigo Sversut; Briso, André Luiz Fraga; Sundfeld Neto, Daniel

2011-01-01

in 1989, correction of the color pattern of teeth can be obtained through the use of whitening products containing carbamide peroxide in custom trays. A considerable margin of clinical success has been shown when diligence to at-home protocols is achieved by the patient and supervised by the professional. Considering these possibilities, this article presents the microabrasion technique for removal of stains on dental enamel, followed by tooth bleaching with carbamide peroxide and composite resin restoration, if required.

Effect of a self-adhesive coating on the load-bearing capacity of tooth-coloured restorative materials.

Science.gov (United States)

Bagheri, R; Palamara, Jea; Mese, A; Manton, D J

2017-03-01

The aim of this study was to compare the flexural strength and Vickers hardness of tooth-coloured restorative materials with and without applying a self-adhesive coating for up to 6 months. Specimens were prepared from three resin composites (RC), two resin-modified glass-ionomer cements (RM-GIC) and two conventional glass-ionomer cements (CGIC). All materials were tested both with and without applying G-Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four-point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope. Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent. The load-bearing capacity of the restorative materials was affected by applying self-adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM-GIC and RC. © 2016 Australian Dental Association.

Advancements in all-ceramics for dental restorations and their effect on the wear of opposing dentition

Science.gov (United States)

Rashid, Haroon; Sheikh, Zeeshan; Misbahuddin, Syed; Kazmi, Murtaza Raza; Qureshi, Sameer; Uddin, Muhammad Zuhaib

2016-01-01

Tooth wear is a process that is usually a result of tooth to tooth and/or tooth and restoration contact. The process of wear essentially becomes accelerated by the introduction of restorations inside the oral cavity, especially in case of opposing ceramic restorations. The newest materials have vastly contributed toward the interest in esthetic dental restorations and have been extensively studied in laboratories. However, despite the recent technological advancements, there has not been a valid in vivo method of evaluation involving clinical wear caused due to ceramics upon restored teeth and natural dentition. The aim of this paper is to review the latest advancements in all-ceramic materials, and their effect on the wear of opposing dentition. The descriptive review has been written after a thorough MEDLINE/PubMed search by the authors. It is imperative that clinicians are aware of recent advancements and that they should always consider the type of ceramic restorative materials used to maintain a stable occlusal relation. The ceramic restorations should be adequately finished and polished after the chair-side adjustment process of occlusal surfaces. PMID:28042280

Restoration of a fractured central incisor.

Science.gov (United States)

Olson, Bradley J

2012-03-01

The treatment of a traumatically damaged single central incisor poses significant challenges relative to function and esthetics to the restoring clinician. Providing a good long-term prognosis is paramount when determining whether to maintain or extract a structurally compromised tooth. Successful restoration demands timely and thorough risk assessment along with excellent communication with both the patient and the laboratory fabricating the restoration.

A Dental Hygienist's and Therapist's Guide to the Management of Tooth Erosion.

Science.gov (United States)

Ariyanayagam, Yana

2016-08-01

Dental care professionals can support patients to prevent and manage tooth erosion. The role of the dentist is to restore the structure and function of teeth damaged by acid erosion, while the role of the dental hygienist therapist is to work alongside the dentist to help manage and reduce the risk of tooth erosion. This article will highlight how the dental hygienist or therapist can identify tooth erosion. It will describe the features of tooth erosion and outline the causes. This article will discuss preventative care options for patients who are at risk of tooth erosion, including specific oral hygiene instructions, fluoride advice and use of other dental products.

Posterior composite restoration update: focus on factors influencing form and function

Science.gov (United States)

Bohaty, Brenda S; Ye, Qiang; Misra, Anil; Sene, Fabio; Spencer, Paulette

2013-01-01

Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient’s caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth–restoration bond, and the ability of the restorative material to produce a sealed tooth–restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of posterior composite restorations, the emphasis must remain on advancing our understanding of the clinical variables that impact the formation of a durable seal at the restoration–tooth interface. This paper presents an update of existing technology and underscores the mechanisms that negatively impact the durability of posterior composite restorations in permanent teeth. PMID:23750102

Esthetic enhancement of a traumatized anterior tooth with a combination of forced eruption and tooth alignment: a case report

Science.gov (United States)

Kang, So-Hee; Jin, Myoung-Uk; Kim, Sung-Kyo

2016-01-01

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result. PMID:27508163

Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

DEFF Research Database (Denmark)

Karlsson, U; Gotfredsen, K; Olsson, C

1998-01-01

This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been...

[Posterior ceramic bonded partial restorations].

Science.gov (United States)

Mainjot, Amélie; Vanheusden, Alain

2006-01-01

Posterior ceramic bonded partial restorations are conservative and esthetic approaches for compromised teeth. Overlays constitute a less invasive alternative for tooth tissues than crown preparations. With inlays and onlays they are also indicated in case of full arch or quadrant rehabilitations including several teeth. This article screens indications and realization of this type of restorations.

Patient Discomfort Following Single-Tooth Implant Placement

DEFF Research Database (Denmark)

Spin-Neto, Rubens; Pontes, Ana Emília Farias; Wenzel, Ann

2014-01-01

scores for pain and swelling decreased continuously over the time period in both groups. Conclusions: The longer treatment time in IR didn't increase patients' perception of pain, bleeding and swelling, compared to CR. The impact of immediate tooth restoration on patients' esthetic outcome should...

Minimally invasive restoration of a maxillary central incisor with a partial veneer.

Science.gov (United States)

Horvath, Sebastian; Schulz, Claus-Peter

2012-01-01

Minimally invasive treatment modalities allow for the preservation of sound tooth substance. However, by limiting the preparation to the extent of a defect, the transition between restoration and natural tooth may be moved to more visible areas. The materials available for the restoration of a limited defect in the anterior area are either resin composite materials or porcelain. A patient was presented who asked for the replacement of a discolored filling on the maxillary right central incisor. Tooth preparation was limited to the extent of the old filling, and a porcelain partial veneer restoration was fabricated. Despite the horizontal finish line in the middle of the clinical crown, a result could be achieved that was regarded as a success by the patient. This type of restoration proves to be a suitable alternative to direct composite restorations in the anterior area for the reconstruction of a limited defect, eg, due to a dental trauma.

The randomized shortened dental arch study: tooth loss over five years.

Science.gov (United States)

Walter, M H; Hannak, W; Kern, M; Mundt, T; Gernet, W; Weber, A; Wöstmann, B; Stark, H; Werner, D; Hartmann, S; Range, U; Jahn, F; Passia, N; Pospiech, P; Mitov, G; Brückner, J; Wolfart, S; Busche, E; Luthardt, R G; Heydecke, G; Marré, B

2013-04-01

The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA). In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis (PRDP) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion. No implants were placed. The primary outcome was tooth loss. Of 152 treated patients, 132 patients reached the 5-year examination. Over 5 years, 38 patients experienced tooth loss. For the primary outcome tooth loss, the Kaplan-Meier survival rates at 5 years were 0.74 (95% CI 0.64, 0.84) in the PRDP group and 0.74 (95% CI 0.63, 0.85) in the SDA group. For tooth loss in the study jaw, the survival rates at 5 years were 0.88 (95% CI 0.80, 0.95) in the PRDP group and 0.84 (95% CI 0.74, 0.93) in the SDA group. The differences were not significant. No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found. The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable. The influence of the type of prosthetic treatment on tooth loss might have been overestimated. Regarding our results, the patient's view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs.

Soft and Hard Tissue Changes Following Immediate Placement or Immediate Restoration of Single-Tooth Implants in the Esthetic Zone: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Yan, Qi; Xiao, Li-Qun; Su, Mei-Ying; Mei, Yan; Shi, Bin

This systematic review aimed to compare immediate protocols with conventional protocols of single-tooth implants in terms of changes in the surrounding hard and soft tissue in the esthetic area. Electronic and manual searches were performed in PubMed, EMBASE, Cochrane, and other data systems for research articles published between January 2001 and December 2014. Only randomized controlled trials (RCTs) reporting on hard and or soft tissue characteristics following a single-tooth implant were included. Based on the protocol used in each study, the included studies were categorized into three groups to assess the relationships between the factors and related esthetic indexes. Variables such as marginal bone level changes (mesial, distal, and mean bone level), peri-implant soft tissue changes (papilla level, midbuccal mucosa, and probing depth), and other esthetic indices were taken into consideration. The data were analyzed using RevMan version 5.3, Stata 12, and GRADEpro 3.6.1 software. A total of 13 RCTs met the inclusion criteria. Four studies examined immediate implant placement, five studies examined immediate implant restoration, and four studies examined immediate loading. Comparing the bone level changes following immediate and conventional restoration, no significant differences were found in the bone level of the mesial site (standard mean difference [SMD] = -0.04 mm; 95% confidence interval [CI]: -0.25 to 0.17 mm), the distal site (SMD = -0.15 mm; 95% CI: -0.38 to 0.09 mm), and the mean bone level changes (SMD = 0.05 mm; 95% CI: -0.18 to 0.27 mm). The difference in the marginal bone level changes between immediate and conventional loading was also not statistically significant (SMD = -0.05 mm; 95% CI: -0.15 to 0.06 mm for the mesial site and SMD = -0.02 mm; 95% CI: -0.09 to 0.05 mm for the distal site). Soft tissue changes following immediate and conventional restoration reported no significant differences in the papillae level of the mesial site (SMD = 0

STRATIFICATION TECHNIQUE IN MAXILLARY ANTERIOR INCISORS RESTORATION

Directory of Open Access Journals (Sweden)

Janet Kirilova

2014-08-01

Full Text Available Background: Because of their main characteristics: transparency, opalescence and color density, the tooth structures are extremely difficult to restore by means of completely inconspicuous restorations of the natural tooth tissue characteristics. The aim is to show successful aesthetic restoration of III Class dental lesions in upper incisors by means of high quality composites. Materials and method: A female patient visited the clinic being not satisfied with the esthetics of her front teeth. The intraoral examination showed previous restorations and carious lesions in 12, 11, 21, 22. After defining the tooth color a silicone key was made. The treatment was performed under anesthesia, the existing restorations were removed and the carious lesions in teeth 11, 12, 21, 22 were treated with restorations using Vanini edge preparation. The teeth were restored by means of stratification technique. After etching and rinsing, bonding was applied for 20 sec. and then polymerized. After fixing the silicone key enamel shade was applied and then dentine shades UD2, UD3, UD4 of 0.5mm thickness each. The polymerization was done layer by layer. Applied were 10 to 15 layers in total. The composite material was preheated in oven up to 55. Teeth 21 and 22 are restored with Enamel Plus HRi (Micerium. Results and Discussion: Excellent aesthetics is achieved with composite material. They have enamel and dentine shades and allow high quality aesthetics. The polishing is excellent in Enamel Plus HRi (Micerium which is typical for this type of composite. The result of the carious lesion treatment in this patient is real improvement of the dental appearance of her anterior incisors. Conclusion: Materials show excellent aesthetic results due to their characteristics and the stratification technique used.

Restorative Rehabilitation of a Patient with Dental Erosion

OpenAIRE

AlShahrani, Mohammed Thamer; Haralur, Satheesh B.; Alqarni, Mohammed

2017-01-01

Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clini...

Visualization of in vitro evaluation of restored teeth with synthetic resins by neutron radiography

International Nuclear Information System (INIS)

Barbosa, Andre Luis N.; Crispim, Verginia R.

2013-01-01

The goal of the present study was to evaluate whether the technique of neutron radiography can provide information on strength and adherence in dental restoration with synthetic polymeric materials, particularly as a tool for the analysis of micro leakage and voids. Thus, tooth samples were drilled, producing cavities with similar dimensions in each tooth, and then carefully filled with eight types of resins that are the most commonly used by dentists. After exposing the tooth samples to a neutron beam, their radiographic images were analyzed. This technique gave good results showing that all the tooth samples were suitably restored. (author)

Lock-in thermography, penetrant inspection, and scanning electron microscopy for quantitative evaluation of open micro-cracks at the tooth-restoration interface

Science.gov (United States)

Streza, M.; Hodisan, I.; Prejmerean, C.; Boue, C.; Tessier, Gilles

2015-03-01

The evaluation of a dental restoration in a non-invasive way is of paramount importance in clinical practice. The aim of this study was to assess the minimum detectable open crack at the cavity-restorative material interface by the lock-in thermography technique, at laser intensities which are safe for living teeth. For the analysis of the interface, 18 box-type class V standardized cavities were prepared on the facial and oral surfaces of each tooth, with coronal margins in enamel and apical margins in dentine. The preparations were restored with the Giomer Beautifil (Shofu) in combination with three different adhesive systems. Three specimens were randomly selected from each experimental group and each slice has been analysed by visible, infrared (IR), and scanning electron microscopy (SEM). Lock-in thermography showed the most promising results in detecting both marginal and internal defects. The proposed procedure leads to a diagnosis of micro-leakages having openings of 1 µm, which is close to the diffraction limit of the IR camera. Clinical use of a thermographic camera in assessing the marginal integrity of a restoration becomes possible. The method overcomes some drawbacks of standard SEM or dye penetration testing. The results support the use of an IR camera in dentistry, for the diagnosis of micro-gaps at bio-interfaces.

Comparative study of nanomechanical properties of cements used in teeth restoration

International Nuclear Information System (INIS)

Peluccio, M S; Bignardi, C; Lombardo, S; Montevecchi, F M; Carossa, S

2007-01-01

The discipline of dental science includes the diagnosis of disease in the mouth and teeth, its manifestations and the procedures involved in the restoration of their integrity and function. Restoration of lost tooth structure with suitable materials plays an integral part in the successful rehabilitation of oral tissues. Several factors influence the performance of dental restorations. These factors include the type of cement used to bond crown restoration to prepared teeth. The nanoindentation method was used to explore the mechanical properties of different types of resin cement polymerized using different techniques. A Nano Indenter XP (from MTS Nano Instruments, USA) was used for the experimental tests. A sample of 40 extracted human teeth were restored using two different resin cements: Variolink II (Ivoclar Vivadent, Liechtenstein) and Venus A2 (Heraeus Kulzer, Germany). Both resin cements are light-cured and one of them is self-cured so that the degree of polymerization would be higher. The data obtained for nanohardness and the Young's modulus were analysed using ANOVA to evaluate the influence of different factors (the resin cement and polymerization technique used, the position on the tooth-restoration interface) and to determine the best performance for restoration. The results obtained could give a useful indication of the choice of cementation technique and of the materials used for the restoration of lost tooth structure in different clinical cases

Heat Transfer and Thermal Stress Analysis of a Mandibular Molar Tooth Restored by Different Indirect Restorations Using a Three-Dimensional Finite Element Method.

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Çelik Köycü, Berrak; İmirzalıoğlu, Pervin

2017-07-01

Daily consumption of food and drink creates rapid temperature changes in the oral cavity. Heat transfer and thermal stress caused by temperature changes in restored teeth may damage the hard and soft tissue components, resulting in restoration failure. This study evaluates the temperature distribution and related thermal stress on mandibular molar teeth restored via three indirect restorations using three-dimensional (3D) finite element analysis (FEA). A 3D finite element model was constructed of a mandibular first molar and included enamel, dentin, pulp, surrounding bone, and indirect class 2 restorations of type 2 dental gold alloy, ceramic, and composite resin. A transient thermal FEA was performed to investigate the temperature distribution and the resulting thermal stress after simulated temperature changes from 36°C to 4 or 60°C for a 2-second time period. The restoration models had similar temperature distributions at 2 seconds in both the thermal conditions. Compared with 60°C exposure, the 4°C condition resulted in thermal stress values of higher magnitudes. At 4ºC, the highest stress value observed was tensile stress (56 to 57 MPa), whereas at 60°C, the highest stress value observed was compressive stress (42 to 43 MPa). These stresses appeared at the cervical region of the lingual enamel. The thermal stress at the restoration surface and resin cement showed decreasing order of magnitude as follows: composite > gold > ceramic, in both thermal conditions. The properties of the restorative materials do not affect temperature distribution at 2 seconds in restored teeth. The pulpal temperature is below the threshold for vital pulp tissue (42ºC). Temperature changes generate maximum thermal stress at the cervical region of the enamel. With the highest thermal expansion coefficient, composite resin restorations exhibit higher stress patterns than ceramic and gold restorations. © 2015 by the American College of Prosthodontists.

A conservative approach for restoring anterior guidance: a case report.

Science.gov (United States)

Pontons-Melo, Juan Carlos; Pizzatto, Eduardo; Furuse, Adilson Yoshio; Mondelli, José

2012-06-01

One of the most common dental problems in today's clinics is tooth wear, specifically when related to bruxism. In such cases, the esthetics of anterior teeth may be compromised when excessive wear to the incisal surfaces occurs. Anterior tooth wear resulting from parafunctional bruxism can be conservatively treated with the use of direct resin composite restorations. This restorative approach has the advantages of presenting good predictability, load resistance, acceptable longevity, preservation of healthy dental tissues, and lower cost when compared with indirect restorations. The use of resin composites to solve esthetic problems, however, requires skill and practice. Thus, the present article demonstrates a conservative approach for restoring the esthetics and function of worn anterior teeth with the aid of direct resin composite restorations and selective occlusal adjustment. A conservative approach to restore anterior teeth with excessive wear is possible with direct resin composites. © 2011 Wiley Periodicals, Inc.

In vivo quantitative evaluation of tooth color with hand-held colorimeter and custom template.

Science.gov (United States)

Shimada, Kazuki; Kakehashi, Yoshiyuki; Matsumura, Hideo; Tanoue, Naomi

2004-04-01

This article presents a technique for quantitatively evaluating the color of teeth, as well as color change in restorations and tooth surfaces. Through use of a custom template made of a thermoplastic polymer and a dental colorimeter, tooth surface color can be recorded periodically at the same location intraorally.

Gingival and dental parameters in the evaluation of aesthetic characteristics of fixed restorations (II

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Obradović-Đuričić Kosovka

2005-01-01

Full Text Available This paper is a continuing evaluation of dental and facial parameters in the estimation of aesthetic characteristic of fixed restorations. First of all, attention is paid to the phenomenon describing the tooth tissue's characteristics (transiucency, opalescence, and transparency. The paper also discusses tooth color as a special occurrence, the position of the lower lip line as well as the symmetry of the smile. In addition to these fundamental objective criteria, the paper also deals with subjective criteria (tooth arrangement and position, variation in tooth form, and relative crown length, which play a part in the successful aesthetic integration of fixed restorations.

Influence of the shape of the layers in photo-cured dental restorations on the shrinkage stress peaks-FEM study.

Science.gov (United States)

Kowalczyk, Piotr

2009-12-01

The aim of the paper is to analyse an influence of the shape of the layers in photo-cured dental restorations of Class I on distribution of shrinkage stresses along the tooth-restoration interface. The study is a continuation of the previous considerations (Kowalczyk and Gambin (2008) [1]), where techniques, which reduce stress concentration at the top of the tooth-restoration interface, were considered. The analysis leads to proposition of new layer forming techniques, which diminish the stress peaks at the interface and prevent the crack propagation process. To find the stress distributions in the dental restoration layers and the tooth tissues the finite element method implemented in the ABAQUS (Simulia, Providence, USA) software is used. For Class I restoration of the premolar tooth, the axisymmetrical model is assumed. The restoration is made of four layers of a photo-cured composite. Between the tooth tissues and the restoration, a layer of bonding agent 0.01mm thick is placed and modeled by FEM with help of the cohesive elements. The assumed model takes into account an influence of changes of elastic properties and viscous effects. For each case of the restoration layers system, the Huber-Mises stresses are analysed. The investigations show that the stresses near the restoration-tooth tissue interface are reduced due to viscous flow of the cured material and due to existence of a thin layer of the bonding agent. However, the stress distribution both, in the restoration and in the tooth tissues, is strongly dependent on a shape of the filling layers. Numerical simulations disclose that stress peaks are located at the top corners of each layer. The top corners of the last layer are the places where microleakage may occur. Stress concentrations at the corners of the preceding layers may lead to a growth of uprising crack. It will be shown that the flat layers in the restoration create relatively high values of the stress peaks. The rounded layers, with shapes

Restoring proximal caries lesions conservatively with tunnel restorations

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Chu CH

2013-07-01

Full Text Available Chun-Hung Chu1, May L Mei,1 Chloe Cheung,1 Romesh P Nalliah2 1Faculty of Dentistry, The University of Hong Kong, Hong Kong, People's Republic of China; 2Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA Abstract: The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. Keywords: operative, practice, tunnel preparation, composite, amalgam, glass ionomer

Assessment of the Effect of Orthodontic Treatment on the Periodontal Health of Endodontically Restored Tooth.

Science.gov (United States)

Jalaluddin, Md; Goyal, Vinod; Naqvi, Zuber A; Gupta, Bhaskar; Asnani, Mohil M; Sonigra, Hitesh M

2017-07-01

Intorduction: Patients usually undergo orthodontic treatment for achieving ideal interocclusal relationship between the dental tissue and bony tissue along with improving the speech, mastication, and facial esthetic appearance. Literature quotes paucity in the studies evaluating the effect of orthodontic treatment on the periodontal health of endodontically treated teeth. Hence, we planned the present study to assess the effect of orthodontic treatment on the periodontal health of endodonti-cally restored tooth. The present study included assessment of 80 patients who underwent orthodontic treatment. All the patients were divided broadly into two study groups: groups I and II. Group I included patients with the absence of endodontically treated teeth, while group II included patients which maxillary central incisors were resorted endodontically. Examination of the periodontal health of the patients was done using the community periodontal index of treatment need (CPITN) around the selected teeth. All the values were recorded during the preorthodontic time, postorthodontic time, and after the first 6 months of starting of the orthodontic treatment. All the results were recorded separately and analyzed. In the groups I and II, 28 and 25 patients respectively, had score of 1, while 10 patients in group I and 12 patients in group II had score of 2. Nonsignificant results were obtained while comparing the CPITN score in between the two study groups when measured at the pre-, intra-, and postortho time. In patients undergoing orthodontic treatment, having endodontically resorted teeth, no difference exists in relation to the periodontal health. Orthodontic treatment can be safely carried in patients with endodontically restored teeth.

Detection of Carious Lesions and Restorations Using Particle Swarm Optimization Algorithm

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Mohammad Naebi

2016-01-01

Full Text Available Background/Purpose. In terms of the detection of tooth diagnosis, no intelligent detection has been done up till now. Dentists just look at images and then they can detect the diagnosis position in tooth based on their experiences. Using new technologies, scientists will implement detection and repair of tooth diagnosis intelligently. In this paper, we have introduced one intelligent method for detection using particle swarm optimization (PSO and our mathematical formulation. This method was applied to 2D special images. Using developing of our method, we can detect tooth diagnosis for all of 2D and 3D images. Materials and Methods. In recent years, it is possible to implement intelligent processing of images by high efficiency optimization algorithms in many applications especially for detection of dental caries and restoration without human intervention. In the present work, we explain PSO algorithm with our detection formula for detection of dental caries and restoration. Also image processing helped us to implement our method. And to do so, pictures taken by digital radiography systems of tooth are used. Results and Conclusion. We implement some mathematics formula for fitness of PSO. Our results show that this method can detect dental caries and restoration in digital radiography pictures with the good convergence. In fact, the error rate of this method was 8%, so that it can be implemented for detection of dental caries and restoration. Using some parameters, it is possible that the error rate can be even reduced below 0.5%.

Ozone therapy and restorative dentistry: a literature review ...

African Journals Online (AJOL)

This approach is being further reinforced with the emergence of ozone therapy in the management of tooth decay. Ozone therapy is the treatment of the tooth with a mixture of oxygen and ozone. The aim of this review was to provide a comprehensive literature on ozone therapy and on the different areas of restorative dental ...

RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

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Yadav

2015-07-01

Full Text Available Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatment alternative for restoration of such teeth. The Richmond crown was introduced in 1878 and incorporated a threaded tube in the canal with a screw retained crown. It was later modified to eliminate the threaded tube and was redesigned as a one piece dowel and crown. This case report shows restoration of badly mutilated posterior teeth with Richmond crown.

The confusing array of tooth-colored crowns.

Science.gov (United States)

Christensen, Gordon J

2003-09-01

The venerable PFM crown or fixed prosthesis still dominates the tooth-colored restoration market. However, use of PFMs is declining slightly, as the many new all-ceramic and resin-based composite crowns and fixed-prosthesis products flood the market. Several situations may indicate the use of materials other than PFM. They include patients requiring a high level of esthetic acceptability, patients with proven or perceived allergies to the metals used in dentistry and bruxing or clenching patients with metal allergies or desire to eliminate metal from their mouths. PFM restorations have been proven during 40 years of successful use. They provide acceptable esthetics for most situations, minimal fracture during service, proven ability to serve in multiple-unit situations and excellent fit, and the profession has detailed knowledge of these restorations' advantages, disadvantages and physical characteristics. PFM restorations have only a few well-known negative characteristics. Be cautious as you elect to move from the reliability and positive history of PFM to relatively unknown types of restorations.

Parameters affecting tooth loss during periodontal maintenance in a Greek population.

Science.gov (United States)

Tsami, Alexandra; Pepelassi, Eudoxie; Kodovazenitis, George; Komboli, Mado

2009-09-01

Investigators have evaluated predictive parameters of tooth loss during the maintenance phase (MP). The authors conducted a retrospective study to evaluate the rate of tooth loss and to explore the parameters that affect tooth loss during MP in a Greek population. A periodontist administered periodontal treatment and maintenance care to 280 participants with severe periodontitis for a mean period +/- standard deviation of 10.84 +/- 2.13 years. The periodontist recorded the following parameters for each participant: oral hygiene index level, simplified gingival index level, clinical attachment level, probing depth measurements, initial tooth prognosis, smoking status, tooth loss during active periodontal treatment and MP, and compliance with suggested maintenance visits. The authors found that total tooth loss during active treatment (n = 1,427) was greater than during MP (n = 918) and was associated with the initial tooth prognosis, tooth type group, participants' compliance with suggested maintenance visits, smoking status and acceptability of the quality of tooth restorations. Most of the teeth extracted during maintenance had an initial guarded prognosis (n = 612). Participants whose compliance was erratic had a greater risk of undergoing tooth extraction than did participants whose compliance was complete. Participants' initial tooth prognosis, tooth type, compliance with suggested maintenance visits and smoking status affected tooth loss during MP. Initial guarded prognosis and erratic compliance increased the risk of undergoing tooth extraction during maintenance. Determining predictive parameters for disease progression and tooth loss provides critical information to clinicians so that they can develop and implement rational treatment planning.

Molar incisor hypomineralization (MIH): conservative treatment management to restore affected teeth.

Science.gov (United States)

Fragelli, Camila Maria Bullio; Souza, Juliana Feltrin de; Jeremias, Fabiano; Cordeiro, Rita de Cássia Loiola; Santos-Pinto, Lourdes

2015-01-01

The purpose of this study was to evaluate the 12-month clinical performance of glass ionomer restorations in teeth with MIH. First permanent molars affected by MIH (48) were restored with glass ionomer cement (GIC) and evaluated at baseline, at 6 and at 12 months, by assessing tooth enamel breakdown, GIC breakdown and caries lesion associations. The data were analyzed using the chi-square test and actuarial survival analysis. The likelihood of a restored tooth remaining unchanged at the end of 12 months was 78%. No statistically significant difference was observed in the association between increased MIH severity and caries at baseline (p > 0.05) for a 6-month period, or between increased MIH severity and previous unsatisfactory treatment at baseline (p > 0.05) for both a 6- and 12-month period. A statistically significant difference was observed in the association between increased MIH severity and extension of the restoration, involving 2 or more surfaces (p MIH severity and caries at baseline (p < 0.05) at a 12-month period. Because the likelihood of maintaining the tooth structures with GIC restorations is high, invasive treatment should be postponed until the child is sufficiently mature to cooperate with the treatment, mainly of teeth affected on just one face.

Replacement of a hopeless maxillary central incisor: a technique for the fabrication of an immediate implant-supported interim restoration.

Science.gov (United States)

Graiff, Lorenzo; Vigolo, Paolo

2012-04-01

Placement of a dental implant and an interim restoration in the esthetic zone immediately following tooth extraction is now a common procedure. However, in such clinical situations, the fabrication of an appropriate interim restoration may be challenging. The aim of this article is to present a technique for modifying the extracted tooth so it can be used as an implant-supported interim restoration.

Posterior composite restoration update: focus on factors influencing form and function

Directory of Open Access Journals (Sweden)

Bohaty BS

2013-05-01

Full Text Available Brenda S Bohaty,1,2 Qiang Ye,3 Anil Misra,3,4 Fabio Sene,6 Paulette Spencer3,51Department of Pediatric Dentistry, University of Missouri-Kansas City School of Dentistry, Kansas City, MO, USA; 2Department of Pediatric Dentistry, Children's Mercy Hospital, Kansas City, MO, USA; 3Bioengineering Research Center, 4Department of Civil, Environmental, and Architectural Engineering, 5Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA; 6Department of Restorative Dentistry, State University of Londrina, School of Dentistry, Londrina, BrazilAbstract: Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient's caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth–restoration bond, and the ability of the restorative material to produce a sealed tooth–restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of

An approach to biomimetics: the natural CAD/CAM restoration: a clinical report.

Science.gov (United States)

Schlichting, Luís Henrique; Schlichting, Kathryn Klemz; Stanley, Kyle; Magne, Michel; Magne, Pascal

2014-02-01

Those in the dental field have always pursued the perfect dental material for the treatment of compromised teeth. Gold, amalgam, composite resin, glass ionomer, and porcelain have been used. Tooth-like restorative materials (composite resin and porcelain) combined with an effective hard tissue bond have met the growing demand for esthetic or metal-free restorations in the past 15 to 20 years. However, none of those materials can fully mimic the unique properties of dentin (compliance and crack-stopping behavior) and enamel (wear resistance, function). The aim of this article is to report the restoration of an extensively damaged tooth with a natural restoration obtained by milling an extracted third molar tooth with a computer-aided design and computer-aided manufacturing (CAD/CAM) system. The main benefit of this novel technique is the replacement of lost tissues by actual enamel and dentin, with the potential to recover mechanical, esthetic, and biologic properties. The indication for extracting third molars and premolars because of impaction or for orthodontic reasons makes these posterior teeth readily available. The innovation of the method presented here is the optimal use of the extracted tooth substrate thanks to its positioning technique in the CAD/CAM milling chamber. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Geographic Variations in the EPR Spectrum of Tooth Enamel

International Nuclear Information System (INIS)

Romanyukha, A.A.; Hayes, R.B.; Haskell, E.H.; Kenner, G.H.

1999-01-01

The presence of stable radiation-induced radicals in the mineral component of tooth enamel allows use of this material as a biological dosemeter. Estimation of the dose absorbed in tooth enamel can be done by EPR. Generally, for the purpose of dose reconstruction, the EPR spectrum of tooth enamel is interpreted in terms of two main components. The first is a broad background signal often called the native signal centered at a g value of 2.0045. The origin of this signal is not precisely known. The second main component in the tooth enamel spectrum is purely radiation induced and can be used for retrospective dosimetry. Internal structure of the native signal and variations of its amplitude and linewidth were investigated for the samples prepared from modern teeth obtained from different geographic locations (USA and Russia). Possible reasons for the variations observed are discussed as are the potential effects of the variations on the reliability of dose estimation. (author)

Tetracycline tooth discolouration in Benin City | Sede | Journal of ...

African Journals Online (AJOL)

Journal of Medicine and Biomedical Research ... This retrospective study was conducted to examine the incidence and pattern of tetracycline-related tooth discolouration in patients seen at the restorative dental clinic of ... These patients accounted for 2.2% of the 3750 patients that were seen during the period under review.

Marginal microfiltration in amalgam restorations. Review

OpenAIRE

Lahoud Salem, Víctor

2014-01-01

The present articule is review references from phenomenon of microfiltration in restorations with amalgam and yours consecuents in changes of color in the interface tooth-restorations, margin deterioted , sensitivity dentinarea postoperate, caries secondary and pulp inflamation. Besides naming the mechanicals for to reduce microfiltration, and yours effects for use of sealers dentinaries representation for the varnish cavitys and adhesive systens Conclusive indicate wath the amalgam is the ma...

Influence of crosshead speed on failure load and failure mode of restored maxillary premolars

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Lucas Zago NAVES

2016-01-01

Full Text Available We analyzed the effect of the crosshead speed of an applied load on failure load and failure mode of restored human premolars. Fifty intact, noncarious human premolars were selected. Class II mesio-occlusodistal preparations were made with a water-cooled high-speed preparation machine, and the teeth were restored with composite resin. The specimens were divided into five groups (n = 10 each and tested individually in a mechanical testing machine, in which a 6.0-mm-diameter steel cylinder was mounted to vary the crosshead speed: v0.5: 0.5 mm/min; v1: 1.0 mm/min; v2.5: 2.5 mm/min; v5: 5.0 mm/min; and v10: 10.0 mm/min. The cylinder contacted the facial and lingual ridges beyond the margins of the restorations. Peak load to fracture was measured for each specimen (N. The means were calculated and analyzed with one-way analysis of variance followed by Tukey's test (a = 0.05. The mean load at failure values were (N as follows: v0.5, 769.4 ± 174.8; v1, 645.2 ± 115.7; v5, 614.3 ± 126.0; v2.5, 609.2 ± 208.1; and v10, 432.5 ± 136.9. The fracture modes were recorded on the basis of the degree of the tooth structural and restorative damage: (I fracture of the restoration involving a small portion of the tooth; (II fractures involving the coronal portion of the tooth with cohesive failure of the composite resin; (III oblique tooth and restoration fracture with periodontal involvement; and (IV vertical root and coronal fracture. Varying crosshead speeds of 0.5–5.0 mm/min did not influence the failure load of restored maxillary premolars; however, increasing the crosshead speed to 10 mm/min decreased the failure load values and the degree of tooth structural damage.

Collarless metal ceramic restorations to obscure the umbrella effect

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Afroz Shaista

2010-01-01

Full Text Available Esthetics with porcelain fused to metal restoration in the anterior region can be adversely affected due to the inadequate teeth preparations and design of the prosthesis. We presented here a case report where esthetics was compromised due to darkening of the interdental papilla and marginal gingival and overcontoured restorations in relation to porcelain fused to metal restorations. Good esthetic results were obtained by using basic principles of tooth preparation and using collarless metal ceramic restorations.

When is an implant ready for a tooth?

Science.gov (United States)

Tupac, Robert G

2003-12-01

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

Comparative Evaluation of Marginal Discrepancy in Tooth Colored Self Cure Acrylic Provisional Restorations With and Without Reinforcement of Glass Beads: An In-Vitro Study.

Science.gov (United States)

Yasangi, Manoj Kumar; Mannem, Dhanalakshmi; Bommireddy, Vikram Simha; Neturi, Sirisha; Ravoori, Srinivas; Jyothi

2015-05-01

This invitro study was conducted to compare and evaluate marginal discrepancy in two types of tooth colored self cure provisional restorative materials {DPI&UNIFAST TRAD} before and after reinforcement of glass beads. The aim of the present study was to evaluate and compare marginal discrepancy in two types of provisional restorative materials (DPI and UNI FAST TRAD) before and after reinforcement with Glass beads. Tooth shaped resin copings were fabricated on custom made brass metal die. A total of 60 resin copings were fabricated in which 30 samples were prepared with DPI and 30 samples with UNIFAST material. Each group of 30 samples were divided in to two sub groups in which 15 samples were prepared with glass bead reinforcement and 15 samples without reinforcement. The marginal discrepancy was evaluated with photomicroscope {Reichet Polyvar 2 met} by placing the resin copings on custom made brass resin coping holder. Measurements obtained were statistically analysed by unpaired t-test to know any significance between two variables. Unreinforced DPI specimens had shown lower marginal discrepancy (442.82) than reinforced specimens (585.77). Unreinforced UNIFAST specimens have shown high values of marginal discrepancy (592.83) than reinforced specimens (436.35). p-value between reinforced and unreinforced specimens of DPI (p=0.0013) and UNIFAST (p= 0.0038) has shown statistical significance. This in-vitro study revealed that unreinforced DPI specimens have shown lower marginal discrepancy than reinforced specimens and unreinforced UNIFAST specimens have shown higher values of marginal discrepancy than reinforced specimens.

Comparative Evaluation of Marginal Discrepancy in Tooth Colored Self Cure Acrylic Provisional Restorations With and Without Reinforcement of Glass Beads: An In-Vitro Study

Science.gov (United States)

Yasangi, Manoj Kumar; Mannem, Dhanalakshmi; Neturi, Sirisha; Ravoori, Srinivas; Jyothi

2015-01-01

Context This invitro study was conducted to compare and evaluate marginal discrepancy in two types of tooth colored self cure provisional restorative materials {DPI&UNIFAST TRAD} before and after reinforcement of glass beads. Aim The aim of the present study was to evaluate and compare marginal discrepancy in two types of provisional restorative materials (DPI and UNI FAST TRAD) before and after reinforcement with Glass beads. Materials and Methods Tooth shaped resin copings were fabricated on custom made brass metal die. A total of 60 resin copings were fabricated in which 30 samples were prepared with DPI and 30 samples with UNIFAST material. Each group of 30 samples were divided in to two sub groups in which 15 samples were prepared with glass bead reinforcement and 15 samples without reinforcement. The marginal discrepancy was evaluated with photomicroscope {Reichet Polyvar 2 met} by placing the resin copings on custom made brass resin coping holder. Results Measurements obtained were statistically analysed by unpaired t-test to know any significance between two variables. Unreinforced DPI specimens had shown lower marginal discrepancy (442.82) than reinforced specimens (585.77). Unreinforced UNIFAST specimens have shown high values of marginal discrepancy (592.83) than reinforced specimens (436.35). p-value between reinforced and unreinforced specimens of DPI (p=0.0013) and UNIFAST (p= 0.0038) has shown statistical significance. Conclusion This in-vitro study revealed that unreinforced DPI specimens have shown lower marginal discrepancy than reinforced specimens and unreinforced UNIFAST specimens have shown higher values of marginal discrepancy than reinforced specimens. PMID:26155574

Molar incisor hypomineralization (MIH: conservative treatment management to restore affected teeth

Directory of Open Access Journals (Sweden)

Camila Maria Bullio FRAGELLI

2015-01-01

Full Text Available The purpose of this study was to evaluate the 12-month clinical performance of glass ionomer restorations in teeth with MIH. First permanent molars affected by MIH (48 were restored with glass ionomer cement (GIC and evaluated at baseline, at 6 and at 12 months, by assessing tooth enamel breakdown, GIC breakdown and caries lesion associations. The data were analyzed using the chi-square test and actuarial survival analysis. The likelihood of a restored tooth remaining unchanged at the end of 12 months was 78%. No statistically significant difference was observed in the association between increased MIH severity and caries at baseline (p > 0.05 for a 6-month period, or between increased MIH severity and previous unsatisfactory treatment at baseline (p > 0.05 for both a 6- and 12-month period. A statistically significant difference was observed in the association between increased MIH severity and extension of the restoration, involving 2 or more surfaces (p < 0.05 at both periods, and between increased MIH severity and caries at baseline (p < 0.05 at a 12-month period. Because the likelihood of maintaining the tooth structures with GIC restorations is high, invasive treatment should be postponed until the child is sufficiently mature to cooperate with the treatment, mainly of teeth affected on just one face.

Posterior bulk-filled resin composite restorations.

DEFF Research Database (Denmark)

van Dijken, Jan WV; Pallesen, Ulla

2016-01-01

up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...... Class II, 4 SDR-CeramX mono+ and 6 CeramXmono+-only restorations. The main reasons for failurewere tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled-1.1% and for the resin composite-only restorations 1...

Multidisciplinary Management of Complicated Crown-Root Fracture of an Anterior Tooth Undergoing Apexification

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Merve Mese

2015-01-01

Full Text Available The purpose of this case report was to present the multidisciplinary management of a subgingival crown-root fracture of a patient undergoing apexification treatment. A 12-year-old male patient was referred to the pediatric dentistry clinic with an extensive tooth fracture of the right permanent maxillary lateral incisor. Clinical and radiographic examinations revealed the presence of a complicated crown-root fracture, which had elongated to the buccal subgingival area. The dental history disclosed that the apexification procedure had been started to be performed after his first trauma experience and he had neglected his appointment. The coronal fragment was gently extracted; endodontic treatment was performed; flap surgery was performed to make the fracture line visible. The coronal fragment was reattached to the root fragment with a dual-cure luting composite. A fiber post was stabilized and the access cavity of the tooth was restored with composite resin. At the end of the 24th month, the tooth was asymptomatic, functionally, esthetically acceptable and had no periapical pathology. It is important for the patients undergoing apexification treatment to keep their appointments because of the fracture risk. Restoration of the fractured tooth by preparing retention grooves and a bonding fiber-reinforced post are effective and necessary approaches for successful management.

Contemporary permanent tooth dimensions, with comparisons to G.V. Black's data.

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Harris, Edward F; Burris, Benjamin G

2003-01-01

The tooth dimensions most commonly cited in the dental literature are those published by the famous restorative dentist G. V. Black late in the 19th century. We report here on the crown dimensions of a large series of contemporary North American Whites and show that Black's values differ significantly from modern values, but not in any consistent or predictable fashion. Black supplied no information about the nature of his sample. We suggest that it may be time to replace Black's data with modern tooth size standards.

DH and ESPI laser interferometry applied to the restoration shrinkage assessment

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Campos, L.M.P.; Parra, D.F.; Vasconcelos, M.R.; Vaz, M.; Monteiro, J.

2014-01-01

In dental restoration postoperative marginal leakage is commonly associated to polymerization shrinkage effects. In consequence the longevity and quality of restorative treatment depends on the shrinkage mechanisms of the composite filling during the polymerization. In this work the development of new techniques for evaluation of those effects under light-induced polymerization of dental nano composite fillings is reported. The composite resins activated by visible light, initiate the polymerization process by absorbing light in wavelengths at about 470 nm. The techniques employed in the contraction assessment were digital holography (DH) and Electronic Speckle Pattern Interferometry (ESPI) based on laser interferometry. A satisfactory resolution was achieved in the non-contact displacement field measurements on small objects concerning the experimental dental samples. According to a specific clinical protocol, natural teeth were used (human mandibular premolars). A class I cavity was drilled and restored with nano composite material, according to Black principles. The polymerization was monitored by DH and ESPI in real time during the cure reaction of the restoration. The total displacement reported for the material in relation of the tooth wall was 3.7 μm (natural tooth). The technique showed the entire tooth surface (wall) deforming during polymerization shrinkage. - Highlights: • Both of holographic techniques were able to measure the polymerization shrinkage. • The entire tooth surface was deformed during the polymerization shrinkage. • The group with greater percentage of filler showed the lowest value of deformation. • The values of displacement ranged from 0.9 to 3.4 μm

Stem cells applications in bone and tooth repair and regeneration: New insights, tools, and hopes.

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Abdel Meguid, Eiman; Ke, Yuehai; Ji, Junfeng; El-Hashash, Ahmed H K

2018-03-01

The exploration of stem and progenitor cells holds promise for advancing our understanding of the biology of tissue repair and regeneration mechanisms after injury. This will also help in the future use of stem cell therapy for the development of regenerative medicine approaches for the treatment of different tissue-species defects or disorders such as bone, cartilages, and tooth defects or disorders. Bone is a specialized connective tissue, with mineralized extracellular components that provide bones with both strength and rigidity, and thus enable bones to function in body mechanical supports and necessary locomotion process. New insights have been added to the use of different types of stem cells in bone and tooth defects over the last few years. In this concise review, we briefly describe bone structure as well as summarize recent research progress and accumulated information regarding the osteogenic differentiation of stem cells, as well as stem cell contributions to bone repair/regeneration, bone defects or disorders, and both restoration and regeneration of bones and cartilages. We also discuss advances in the osteogenic differentiation and bone regeneration of dental and periodontal stem cells as well as in stem cell contributions to dentine regeneration and tooth engineering. © 2017 Wiley Periodicals, Inc.

Numerical fatigue 3D-FE modeling of indirect composite-restored posterior teeth.

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Ausiello, Pietro; Franciosa, Pasquale; Martorelli, Massimo; Watts, David C

2011-05-01

In restored teeth, stresses at the tooth-restoration interface during masticatory processes may fracture the teeth or the restoration and cracks may grow and propagate. The aim was to apply numerical methodologies to simulate the behavior of a restored tooth and to evaluate fatigue lifetimes before crack failure. Using a CAD-FEM procedure and fatigue mechanic laws, the fatigue damage of a restored molar was numerically estimated. Tessellated surfaces of enamel and dentin were extracted by applying segmentation and classification algorithms, to sets of 2D image data. A user-friendly GUI, which enables selection and visualization of 3D tessellated surfaces, was developed in a MatLab(®) environment. The tooth-boundary surfaces of enamel and dentin were then created by sweeping operations through cross-sections. A class II MOD cavity preparation was then added into the 3D model and tetrahedral mesh elements were generated. Fatigue simulation was performed by combining a preliminary static FEA simulation with classical fatigue mechanical laws. Regions with the shortest fatigue-life were located around the fillets of the class II MOD cavity, where the static stress was highest. The described method can be successfully adopted to generate detailed 3D-FE models of molar teeth, with different cavities and restorative materials. This method could be quickly implemented for other dental or biomechanical applications. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Glass ionomer-silver cermet Class II tunnel-restorations for primary molars.

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Croll, T P

1988-01-01

Tunnel preparations preserve the anatomical marginal ridge and minimize the loss of healthy tooth structure adjacent to the carious lesion. When the practitioner has developed proficiency in restoring class II carious lesions with tunnel restorations, less treatment time is required than with traditional class II preparations. The technique for restoring a primary first molar with a class II carious lesion, using a tunnel preparation and Ketac-Silver restorative material is described.

The compression dome concept: the restorative implications.

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Milicich, Graeme

2017-01-01

Evidence now supports the concept that the enamel on a tooth acts like a compression dome, much like the dome of a cathedral. With an overlying enamel compression dome, the underlying dentin is protected from damaging tensile forces. Disruption of a compression system leads to significant shifts in load pathways. The clinical restorative implications are significant and far-reaching. Cutting the wrong areas of a tooth exposes the underlying dentin to tensile forces that exceed natural design parameters. These forces lead to crack propagation, causing flexural pain and eventual fracture and loss of tooth structure. Improved understanding of the microanatomy of tooth structure and where it is safe to cut teeth has led to a revolution in dentistry that is known by several names, including microdentistry, minimally invasive dentistry, biomimetic dentistry, and bioemulation dentistry. These treatment concepts have developed due to a coalescence of principles of tooth microanatomy, material science, adhesive dentistry, and reinforcing techniques that, when applied together, will allow dentists to repair a compromised compression dome so that it more closely replicates the structure of the healthy tooth.

Survival rates against fracture of endodontically treated posterior teeth restored with full-coverage crowns or resin composite restorations: a systematic review

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Warattama Suksaphar

2017-07-01

Full Text Available This systematic review aims to summarize the current clinical studies that investigated survival rates against fracture of endodontically treated posterior teeth restored with crowns or resin composite restorations. Literature search were performed using keywords. Publications from 1980 to 2016 were searched in PubMed, ScienceDirect, Web of Science, MEDLINE, and SCOPUS. Included studies were selected based on inclusion and exclusion criteria. Three clinical studies were included: 1 randomized controlled trial and 1 prospective and 1 retrospective cohort studies. Pooled survival rates ranged from 94%–100% and 91.9%–100% for crowns and resin composite, respectively. The majority of teeth had no more than 3 surface loss of tooth structure. The studies included were heterogeneous, and were not appropriate for further meta-analysis. Current evidence suggested that the survival rates against the fracture of endodontically treated posterior teeth restored with crowns or resin composites were not significantly different in the teeth with minimum to moderate loss of tooth structure.

Anterior makeover on fractured teeth by simple composite resin restoration

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Eric Priyo Prasetyo

2011-09-01

Full Text Available Background: In daily practice dentists usually treat tooth fractures with more invasive treatments such as crown, veneer and bridges which preparation require more tooth structure removal. While currently there is trend toward minimal invasive dentistry which conserves more tooth structure. This is enhanced with the vast supply of dental materials and equipment in the market, including restorative materials. Provided with these supporting materials and equipment and greater patient’s demand for esthetic treatment, dentists must aware of the esthetics and basic principle of conserving tooth which should retain tooth longevity. Purpose: This article showed that a simple and less invasive composite resin restoration can successfully restore anterior esthetic and function of fractured teeth which generally treated with more invasive treatment options. Case: A 19 year-old female patient came with fracture on 21 and 22. This patient had a previous history of dental trauma about nine years before and was brought to a local dentist for debridement and was given analgesic, the involved teeth were not given any restorative treatment. Case management: The fractured 21 and 22 were conventionally restored with simple composite resin restoration. Conclusion: Fracture anterior teeth would certainly disturbs patient’s appearance, but these teeth could be managed conservatively and economically by simple composite resin restoration.Latar belakang: Dalam praktek sehari-hari pada umumnya dokter gigi merawat fraktur dengan restorasi invasif seperti mahkota, veneer dan jembatan yang semuanya memerlukan pengambilan jaringan gigi lebih banyak, sedangkan saat ini trend perawatan gigi lebih menuju kearah invasif minimal yang mempertahankan jaringan gigi sebanyak mungkin. Keadaan ini ditunjang oleh tersedianya berbagai macam bahan dan peralatan kedokteran gigi di pasaran, termasuk bahan restorasi. Dengan tersedianya bahan dan peralatan yang mendukung serta tingginya

[A case of restoration using IPS empress (staining technique) for upper central incisors].

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Hata, Utako

2007-07-01

The patient had esthetically unacceptable upper left central incisor crowns. The case was restored using Empress (staining technique) for the upper central incisors on both sides. In making all-ceramic crowns, it is necessary to reproduce the shape and color near to those of the natural tooth. We should not overlook the importance of diagnostic waxing-up, provisional restoration, tooth preparation, gingival retraction and others, to achieve excellent appearance, function and biocompatibility. It is effective to use the staining technique for an anterior tooth crown in order to obtain esthetically satisfactory results by the papilla being present in such cases as the distance from the base of the contact point to the crest of the bone is 5 mm or less.

The single-tooth implant treatment of congenitally missing maxillary lateral incisors using angled abutments: A clinical report

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Suleyman Hakan Tuna

2009-01-01

Full Text Available The maxillary lateral incisor is the second most common congenitally absent tooth. There are several treatment options for replacing the missing maxillary lateral incisor, including canine substitution, tooth-supported restoration, or single-tooth implant. Dental implants are an appropriate treatment option for replacing missing maxillary lateral incisor teeth in adolescents when their dental and skeletal development is complete. This case report presents the treatment of a patient with congenitally missing maxillary lateral incisors using dental implants with angled abutments.

A review of heat transfer in human tooth--experimental characterization and mathematical modeling.

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Lin, Min; Xu, Feng; Lu, Tian Jian; Bai, Bo Feng

2010-06-01

With rapid advances in modern dentistry, high-energy output instruments (e.g., dental lasers and light polymerizing units) are increasingly employed in dental surgery for applications such as laser assisted tooth ablation, bleaching, hypersensitivity treatment and polymerization of dental restorative materials. Extreme high temperature occurs within the tooth during these treatments, which may induce tooth thermal pain (TTP) sensation. Despite the wide application of these dental treatments, the underlying mechanisms are far from clear. Therefore, there is an urgent need to better understand heat transfer (HT) process in tooth, thermally induced damage of tooth, and the corresponding TTP. This will enhance the design and optimization of clinical treatment strategies. This paper presents the state-of-the-art of the current understanding on HT in tooth, with both experimental study and mathematical modeling reviewed. Limitations of the current experimental and mathematical methodologies are discussed and potential solutions are suggested. Interpretation of TTP in terms of thermally stimulated dentinal fluid flow is also discussed. Copyright (c) 2010 Academy of Dental Materials. All rights reserved.

Clinical management of a fused upper premolar with supernumerary tooth: a case report

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Kyu-Min Cho

2014-11-01

Full Text Available n dentistry, the term 'fusion' is used to describe a developmental disorder of dental hard tissues. In the permanent dentition, fusion of a normal tooth and a supernumerary tooth usually involves the incisors or canines. However, a few cases of fusion involving premolars have also been reported to date. We present a rare case in which fusion of the maxillary left second premolar and a supernumerary tooth in a 13-year-old girl was diagnosed using cone beam computed tomography (CBCT, Alphard-3030, Asahi Roentgen Ind. Co., Ltd.. The tooth was bicuspidized after routine nonsurgical root canal treatment, and the separated teeth underwent appropriate restoration procedures. The second premolar and supernumerary tooth remained asymptomatic without any signs of inflammation after a follow-up period of 9 years. Identification of anatomical anomalies is important for treatment in cases involving fusion with supernumerary tooth, and therefore the microscopic examinations and CBCT are essential for the diagnosis. Fused teeth can be effectively managed by the comprehensive treatment which includes both endodontic and periodontal procedures.

Factors Affecting the Quality of Tooth Enamel for In Vivo EPR-Based Retrospective Biodosimetry

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Desmet, Celine M.; Leveque, Philippe; Gallez, Bernard

2016-01-01

In vivo electron paramagnetic resonance biodosimetry on tooth enamel is likely to be an important technology for triage of overexposed individuals after a major radiological incident. The accuracy and robustness of the technique relies on various properties of the enamel such as the geometry of the tooth, the presence of restorations, whitening treatments or exposition to sunlight. Those factors are reviewed, and their influence on dosimetry specifically for triage purposes is discussed. (authors)

Partial-coverage posterior ceramic restorations. Part 1: a return to diligence.

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Liebenberg, W H

2001-01-01

The application of multisurfaced tooth-colored restorations in the posterior dentition is an exercise in risk tolerance when dentin occupies the bulk of the tooth substrate. Not only is interfacial integrity capricious, but also a recent in vivo study has confirmed that dentin bond strengths deteriorate with time. Although the literature is replete with esthetic guidelines for posterior restitution, most practicing clinicians appreciate the prime tenet that clinical success involves more than esthetic realism in the posterior dentition. Success with indirect ceramic restorations is dependent on interfacial integrity, which, although multitudinous, is contingently related to operative competence. Innovative clinical techniques are described in this two-part article, along with a discussion of the probationary status of current adhesive options and the need for excellence in all phases of this demanding restorative sequence. Restorative success in the posterior dentition is profoundly influenced by the variability of operative competence and diligence. This article discusses the precincts of posterior indirect ceramic restorations and submits a number of innovative solutions to the clinical challenge.

Sleep bruxism: challenges and restorative solutions

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Mengatto CM

2016-04-01

Full Text Available Cristiane Machado Mengatto, Fábio Herrmann Coelho-de-Souza, Oswaldo Baptista de Souza Junior Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS, Porto Alegre, Brazil Abstract: Bruxism is a parafunctional activity related to clenching or grinding the teeth and tooth wear can be a consequence of sleep bruxism (SB. Management of severe tooth wear due to SB is a challenging situation because of the common reduced amount of remaining dental structure and loss of vertical dimension of occlusion. Rationale for the planning of oral rehabilitation of patients with SB presenting severe tooth wear should rely on evidence-based approaches; however, few studies have discussed properties of dental materials for SB rehabilitation and how to cosmetically manage severe tooth wear. This review aimed to provide an overview into bruxism cosmetic rehabilitation and how this can be implemented with good outcomes for the patient. Keywords: sleep bruxism, restoration, rehabilitation, prosthodontics, dentistry

[Application of target restoration space quantity and quantitative relation in precise esthetic prosthodontics].

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Haiyang, Yu; Tian, Luo

2016-06-01

Target restoration space (TRS) is the most precise space required for designing optimal prosthesis. TRS consists of an internal or external tooth space to confirm the esthetics and function of the final restoration. Therefore, assisted with quantitive analysis transfer, TRS quantitative analysis is a significant improvement for minimum tooth preparation. This article presents TRS quantity-related measurement, analysis, transfer, and internal relevance of three TR. classifications. Results reveal the close bond between precision and minimally invasive treatment. This study can be used to improve the comprehension and execution of precise esthetic prosthodontics.

The junctional epithelium originates from the odontogenic epithelium of an erupted tooth.

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Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

2014-05-02

The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period.

Microleakage of bonded amalgam restorations using different adhesive agents with dye under vacuum: An in vitro study

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Abhishek Parolia

2011-01-01

Clinical Significance: Bonded amalgam restorations prevent over-preparation and reduce the tooth flexure. GIC type I under amalgam provides chemical bonding in between amalgam and tooth structure and thus reduces the microleakage.

EFFECTS OF POLISHING TIME AND THERMALCYCLINGON THE MICROLEAKAGE OF FOUR TOOTH –COLOURED DIRECT RESTORATIVE MATERIALS

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V MORTAZAVI

2002-09-01

Full Text Available Introdaction. Microleakage has been recognized as a major clinical problem with direct filled dental restorations.The purpose of this study was to investigate and to compare the microleakage of four direct filled tooth-coloured materials, evaluation the effects of polishing time and thermocycling on the microleakage of these materials. Methods. Wedge-shaped class V cavities were prepared on buccal and lingual surfaces of 96 intact extracted human molar teeth. The teeth were randomly divided into three treatment groups and four subgroups. The cavities of each subgroup were filled using one of these materials: a conventional glass ionomer; a resin modified glass ionomer; a composite resin and a compomer. Polishing in the teeth of group 1 was done immediately after placement of restorations and in group 2 one week later. In group 3 delayed polishing and thermocycling (X100 was done. All of the teeth were stored in distilled water for one week and then stained with dye, sectioned, and scored for microleakage on occlusal and cervical edges. Results were statistically analyzed by Kruskal wallis and Mann whitney tests. Results. There was a statistically difference between the microleakage scores of four materials (P < 0.001. Immediately polished glass ionomer and compomer groups have significantly more microleakage than delayed polished groups (P < 0.001. Thermocycting could infulence the microleakage of composite on cervical edges (P < 0.05. Discussion. The precense of differences between the nature of materials and also the surface treatment such as primer or etchant application could influence the microleakage. The prescence of differences in reaction rate between the materials and the time that they reach to their adequate mechanical strength and adhesive bond strength lead to presence of differences between the effect of polishing time on the microleakage scores of materials.

In-depth, high-accuracy proteomics of sea urchin tooth organic matrix

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Mann Matthias

2008-12-01

Full Text Available Abstract Background The organic matrix contained in biominerals plays an important role in regulating mineralization and in determining biomineral properties. However, most components of biomineral matrices remain unknown at present. In sea urchin tooth, which is an important model for developmental biology and biomineralization, only few matrix components have been identified. The recent publication of the Strongylocentrotus purpuratus genome sequence rendered possible not only the identification of genes potentially coding for matrix proteins, but also the direct identification of proteins contained in matrices of skeletal elements by in-depth, high-accuracy proteomic analysis. Results We identified 138 proteins in the matrix of tooth powder. Only 56 of these proteins were previously identified in the matrices of test (shell and spine. Among the novel components was an interesting group of five proteins containing alanine- and proline-rich neutral or basic motifs separated by acidic glycine-rich motifs. In addition, four of the five proteins contained either one or two predicted Kazal protease inhibitor domains. The major components of tooth matrix were however largely identical to the set of spicule matrix proteins and MSP130-related proteins identified in test (shell and spine matrix. Comparison of the matrices of crushed teeth to intact teeth revealed a marked dilution of known intracrystalline matrix proteins and a concomitant increase in some intracellular proteins. Conclusion This report presents the most comprehensive list of sea urchin tooth matrix proteins available at present. The complex mixture of proteins identified may reflect many different aspects of the mineralization process. A comparison between intact tooth matrix, presumably containing odontoblast remnants, and crushed tooth matrix served to differentiate between matrix components and possible contributions of cellular remnants. Because LC-MS/MS-based methods directly

Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

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Navin Mishra

2013-01-01

Full Text Available Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF utilizing Choukroun′s method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth.

Assessment of exposures and potential risks to the US adult population from the leaching of elements from gold and ceramic dental restorations.

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Richardson, G Mark; James, Kyle Jordan; Peters, Rachel Elizabeth; Clemow, Scott Richard; Siciliano, Steven Douglas

2016-01-01

Using data from the 2001 to 2004 US National Health and Nutrition Examination Survey (NHANES) on the number and placement of tooth restorations in adults, we quantified daily doses due to leaching of elements from gold (Au) alloy and ceramic restorative materials. The elements with the greatest leaching rates from these materials are often the elements of lowest proportional composition. As a result, exposure due to wear will predominate for those elements of relatively high proportional composition, while exposure due leaching may predominate for elements of relatively low proportional composition. The exposure due to leaching of silver (Ag) and palladium (Pd) from Au alloys exceeded published reference exposure levels (RELs) for these elements when multiple full surface crowns were present. Six or more molar crowns would result in exceeding the REL for Ag, whereas three or more crowns would be necessary to exceed the REL for Pd. For platinum (Pt), the majority of tooth surfaces, beyond just molar crowns, would be necessary to exceed the REL for Pd. Exposures due to leaching of elements from ceramic dental materials were less than published RELs for all components examined here, including having all restorations composed of ceramic.

Re-interventions after restoring teeth-Mining an insurance database.

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Raedel, Michael; Hartmann, Andrea; Priess, Heinz-Werner; Bohm, Steffen; Samietz, Stefanie; Konstantinidis, Ioannis; Walter, Michael H

2017-02-01

The aim of this study was to examine re-interventions after restorative treatment. The data was collected from the digital database of a major German national health insurance company. Only permanent teeth were observed. Placing a permanent restoration other than a crown regardless of involved surfaces and material was the study intervention. The data did not allow for a differentiation between fillings and inlays that were estimated only a very small portion of the restorations. Success was defined as not undergoing any restorative re-intervention with fillings or inlays on the same tooth (primary outcome) and assessed with Kaplan-Meier survival analyses over four years. An additional analysis was conducted rating "crowning" and "extraction" of respective teeth as target events. Differences were tested with the Log-Rank-test. A multivariate Cox regression analyses was carried out. A total of 17,024,344 restorations placed in 4,825,408 anterior teeth and 9,973,177 posterior teeth could be traced. Focussing on the primary outcome re-intervention, the cumulative four-year success rate was 69.9% for one surface restorations, 74.8% for two surface restorations, 66.6% for three surface restorations and 61.0% for four surface and more extended restorations. These differences were significant (prestorations, 67.5% for two surface restorations, 63.0% for three surface restorations and 55.8% for four surface and more extended restorations. The number of restoration surfaces as well as the tooth position remained significant in the multivariate Cox regression. The sustainability of restorative dental treatment under the terms and conditions of the German national health insurance system shows room for improvement. From a public health perspective, special focus should be laid on primary and secondary prevention to minimize the restorative treatment need. This study shows that re-interventions are observed regularly after restorative treatment. Therefore, preventive and

Prosthetic restoration in the single-tooth gap: patient preferences and analysis of the WTP index.

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Augusti, Davide; Augusti, Gabriele; Re, Dino

2014-11-01

The objective of this study was to evaluate the preference of a patients' population, according to the index of willingness to pay (WTP), against two treatments to restore a single-tooth gap: the implant-supported crown (ISC) and the 3-unit fixed partial denture prosthesis (FPDP) on natural teeth. Willingness to pay values were recorded on 107 subjects by asking the WTP from a starting bid of €2000 modifiable through monetary increases or decreases (€100). Data were collected through an individually delivered questionnaire. The characteristics of the population and choices made, the median values and WTP associations with socio-demographic parameters (Mann-Whitney and Kruskal-Wallis tests), correlations between variables (chi-square test in contingency tables) and significant parameters for predicting WTP values obtained in a multiple linear regression model were revealed. The 64% of patients expressed a preference for ISC, while the remaining 36% of the population chose the FPDP. The current therapeutic choice and those carried out in the past were generally in agreement (>70% of cases, P = 0.0001); a relationship was discovered between the anterior and posterior area to the same method of rehabilitation (101 of 107 cases, 94.4%). The WTP median values for ISC were of €3000 and of €2500 in the anterior and posterior areas, respectively. The smallest amount of money has been allocated for FPDP in posterior region (median of €1500). The "importance of oral care" for the patient was a significant predictor, in the regression model analysis, for the estimation of both anterior (P = 0.0003) and posterior (P WTP values. The "previous therapy" variable reached and was just close to significance in anterior (P = 0.0367) and posterior (P = 0.0511) analyses, respectively. Within the limitations of this study, most of the population (64%) surveyed indicated the ISC as a therapeutic solution for the replacement of a single missing tooth, showing a higher

Natural Tooth Pontic: An Instant Esthetic Option for Periodontally Compromised Teeth—A Case Series

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Rishi Raj

2016-01-01

Full Text Available Sudden tooth loss in the esthetic zone of the maxillary or mandibular anterior region can be due to trauma, periodontal disease, or endodontic failure. The treatment options for replacing the missing tooth can vary between removable prosthesis, tooth-supported prosthesis, and implant-supported prosthesis. Irrespective of the final treatment, the first line of management would be to provisionally restore the patient’s esthetic appearance at the earliest, while functionally stabilizing the compromised arch. Using the patient’s own natural tooth as a pontic offers the benefits of being the right size, shape, and color and provides exact repositioning in its original intraoral three-dimensional position. Additionally, using the patient’s platelet concentrate (platelet rich fibrin facilitates early wound healing and preservation of alveolar ridge shape following tooth extraction. The abutment teeth can also be preserved with minimal or no preparation, thus keeping the technique reversible, and can be completed at the chair side thereby avoiding laboratory costs. This helps the patient better tolerate the effect of tooth loss psychologically. The article describes a successful, immediate, and viable technique for rehabilitation of three different patients requiring replacement of a single periodontally compromised tooth in an esthetic region.

An interdisciplinary approach to reconstruct a fractured tooth under an intact all ceramic crown: Case report with four years follow up

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Sudhir Bhandari

2011-01-01

Full Text Available Trauma causing the fracture of a restored tooth with the extracoronal full coverage prosthesis remaining intact is a common occurrence in dental practice. Reconstruction of the damaged tooth foundation and recementation of the crown can pose quite a challenge for the restorative dentist. This case report describes an innovative interdisciplinary chairside technique for the recementation of an all-ceramic crown on a fractured maxillary central incisor. The course of care described is effective, affordable, and saves time in comparison with other treatment options for such clinical situations.

Applying orthodontic tooth extrusion in a patient treated with bisphosphonate and irradiation: a case report.

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Morita, Hiromitsu; Imai, Yuko; Yoneda, Masahiro; Hirofuji, Takao

2017-01-01

Bisphosphonates and irradiation are useful medical treatments, but can often cause oral complications such as medication-related oral necrosis of the jaw (MRONJ) and osteoradionecrosis (ORN) during oral surgery, including tooth extraction. Therefore, we should take all risks into consideration carefully before choosing dental treatment for patients with a medical history of such therapies. A 55-year-old woman who underwent cord blood transplantation to treat extranodal natural killer T (NK/T) cell lymphoma (nasal type IVB) had a medical history of bisphosphonate and irradiation treatments. We treated her residual tooth root by applying orthodontic extrusion to avoid extraction and successfully restored the tooth. Application of an orthodontic tooth extrusion technique for conservative treatment of a residual tooth is a useful means of avoiding MRONJ or ORN in patients who have a medical history of bisphosphonate and irradiation treatments. © 2016 Special Care Dentistry Association and Wiley Periodicals, Inc.

Treatment of a horizontal root-fractured tooth with decoronation procedure: case report

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Selen Esin Yoldaş

2016-05-01

Full Text Available INTRODUCTION: Early loss of permanent anterior teeth due to trauma can cause esthetic and functional problems for young patients. In such cases, replacement of the missing tooth with traditional approaches is possible; however such approaches will reduce the chance of the patient to receive an esthetic and consistent treatment in the future. CASE REPORT: A 12-year-old male patient referred to our clinic with a history of trauma. Complicated crown fracture in tooth no.11 and horizontal root fracture in tooth no. 21 was detected. Following root canal treatment, tooth no. 11 was restored with a fiber post and a strip crown. To avoid alveolar bone loss due to early tooth extraction, decoronation procedure, an alternative approach, was applied to tooth no. 21. This procedure consisted of leaving the root fragment inside the alveolar socket following the removal of the crown. For the rehabilitation of the missing crown, a partial removable prosthesis was implemented. The patient was recalled in 6., 12. and 18. months. Within the follow-up period, no reduction in the alveolar bone level was seen. No sign of infection was evident. The remaining root fragment kept on resorbing. Tooth no. 11 remained symptom-free as well. The patient is still being followed. CONCLUSION: Decoronation is essentially a treatment choice for preventing alveolar bone loss in ankylosed teeth considered for extraction. In this case report, decoronation was shown to be a suitable alternative also for a fractured, non-ankylosed tooth.

Evaluation of the effect of food and beverages on enamel and restorative materials by SEM and Fourier transform infrared spectroscopy.

Science.gov (United States)

Sari, Mustafa Erhan; Erturk, Aliye Gediz; Koyuturk, Alp Erdin; Bekdemir, Yunus

2014-01-01

To examine different types of restorative materials used in children as well as primary and permanent teeth enamel when affected by erosive foods. Buttermilk, fruit yoghurt, Coca-cola, fruit juice, Filtek Z-250, Dyract Extra, Fuji II LC, and Fuji IX and tooth enamel were used. Measurements were performed on 1-day, 1-week, 1-month, 3-month, 6-month time periods by using ATR-FTIR technique and surface of the specimens were examined with SEM. Permanent tooth showed the least change among human tooth samples when compared to restorative materials. Among filler materials, the most change was observed in Fuji IX. In terms of beverages the most changes on absorption peaks obtained from spectra were seen on the samples held in Coca-Cola and orange-juice. The exposure of human enamel and restorative materials to acidic drinks may accelerate the degradation process and so reduce the life time of filler materials at equivalent integral exposure times longer than three months. Clinical Relevance Erosive foods and drinks having acidic potential destroy not only tooth enamel but also restorative materials. Copyright © 2013 Wiley Periodicals, Inc.

Tooth structure and fracture strength of cavities

DEFF Research Database (Denmark)

Mondelli, José; Sene, Fábio; Ramos, Renata Pereira

2007-01-01

This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities......) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using...... mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50...

Confocal microscopic observation of structural changes in glass-ionomer cements and tooth interfaces.

Science.gov (United States)

Watson, T F; Pagliari, D; Sidhu, S K; Naasan, M A

1998-03-01

This study aimed to develop techniques to allow dynamic imaging of a cavity before, during and after placement of glass-ionomer restorative materials. Cavities were cut in recently extracted third molars and the teeth longitudinally sectioned. Each hemisected tooth surface was placed in green modelling compound at 90 to the optical axis of the microscope. The cavity surface was imaged using a video rate confocal microscope in conjunction with an internally focusable microscope objective. The sample on the stage was pushed up to the objective lens which 'clamped' the cover glass onto it. Water, glycerine or oil was placed below the coverglass, with oil above. Internal tooth structures were imaged by changing the internal focus of the objective. The restorative material was then placed into the cavity. Video images were stored either onto video tape or digitally, using a frame grabber, computer and mass memory storage. Software controls produced time-lapse recordings of the interface over time. Preliminary experiments have examined the placement and early maturation of conventional glass-ionomer cements and a syringeable resin-modified glass-ionomer cement. Initial contact of the cement matrix and glass particles was visible as the plastic material rolled past the enamel and dentine, before making a bond. Evidence for water movement from the dentine into the cement has also been seen. After curing, the early dimensional changes in the cements due to water flux were apparent using the time-lapse facility. This new technique enables examination of developing tooth/restoration interfaces and the tracking of movement in materials.

A Comparison of Coronal Tooth Discoloration Elicited by Various Endodontic Reparative Materials

Science.gov (United States)

2015-06-17

operating microscope at 12.8x magnification to be completely intact and free of restorations, cracks , and/or defects. Each tooth was stored separately in...microscope. The buccal enamel -dentin thickness was standardized to 3mm using spring calipers. Teeth were irrigated with 6% NaOCl and dried. All

Preventing Advanced Carious Lesions with Caries Atraumatic Restorative Technique.

Science.gov (United States)

Byrd, Tammi O

2016-06-01

An alternative approach to controlling dental caries and preventing the associated pain, called atraumatic restorative technique (ART), is described for populations in need, where dental hygienists restore decayed teeth with glass ionomer restorations without prior removal of all decayed tooth structure. There are populations whose decay needs are not adequately being met within the current oral health care delivery system. These include those in poverty conditions, vulnerable children, and the elderly who are often in long-term care facilities without adequate resources or opportunities for traditional dentistry. ART provides a viable option for controlling caries and relieving the pain of untreated decay. The purpose of this article is to suggest that the evidence surrounding ART be viewed objectively and that dental hygienists, with additional education in this approach, can contribute to relieving the pain of untreated dental decay. Evidence suggests that teeth can be effectively restored with ART. Dental hygienists represent an appropriate workforce to provide ART with their current background and education combined plus a brief training program; it is suggested that dental hygiene educational programs include ART within the curriculum. Along with dental sealants and fluoride varnish application, ART can be an important component of a comprehensive preventive program to address the unmet needs of vulnerable populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Restorative glass: reversible, discreet restoration using structural glass components

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Faidra Oikonomopoulou

2017-12-01

Full Text Available The application of structural glass as the principal material in restoration and conservation practices is a distinguishable, yet discreet approach. The transparency of glass allows the simultaneous perception of the monument at both its original and present condition, preserving its historical and aesthetical integrity. Concurrently, the material’s unique mechanical properties enable the structural consolidation of the monument. As a proof of concept, the restoration of Lichtenberg Castle is proposed. Solid cast glass units are suggested to complete the missing parts, in respect to the existing construction technique and aesthetics of the original masonry. Aiming for a reversible system, the glass units are interlocking, ensuring the overall stability without necessitating permanent, adhesive connections. This results in an elegant and reversible intervention.

Evaluating the effect of antioxidant agents on shear bond strength of tooth-colored restorative materials after bleaching: A systematic review.

Science.gov (United States)

Feiz, Atiyeh; Mosleh, Hamid; Nazeri, Rahman

2017-07-01

The main objective of the present study was to make a systematic review of how antioxidant agents affect shear bond strength of tooth-colored restorative materials after bleaching. Electronic search was used to extract the related articles on the targeted key words such as "antioxidant", "dental bleaching" and "shear bond strength" (SBS) from MeSH, PubMed, Medline, and Cochrane electronic data bases. These articles were all published before 2016. Inclusion criteria were restricted to English journal articles concerning humans, clinical trials, cohorts and case-control studies. Therefore, systematic reviews, case reports, letters to editors, editorials and congress abstracts were excluded from the analysis. Most studies conducted on the issue have produced experimental data which are rather controversial, and there is no general agreement about the reported outcomes. As an illustration, most studies have not considered the relationship between the type of antioxidant materials and the shear bond strength. In point of fact, some researchers (e.g Kimyai et al.) have concluded that antioxidants like gel and solution leave similar effects on SBS. Alternatively, certain studies (e.g., Kunt et al.) have produced inconclusive data regarding the impact of one week postponement of the restorative process on SBS after the bleaching process. The results of the studies evaluating the role of various adhesive systems used after bleaching have demonstrated that regardless of the type of adhesive system used, applying antioxidants before restorative procedures can adversely affect the bleaching agents utilized for SBS. It has also been suggested that the type of the adhesive system used might be correlated with the magnitude of SBS. The results obtained from the systematic review of the articles under investigation reflected that the use of antioxidant agents, regardless of their type, form, concentration and duration of application, can improve SBS after bleaching. Copyright �

Management of periodontal destruction caused by overhanging dental restoration

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Misnova Misnova

2016-06-01

Full Text Available Periodontal tissue inflammations are occasionally caused by positions of restoration margins, particularly if they are placed subgingivally. A 44-year old male was referred to the Dental and Mouth Hospital of Dentistry Faculty Hasanuddin University with the chief complaint of severe pain at right posterior maxillary. Clinical examinations demonstrate a 7-mm periodontal pocket at buccal aspect of 16 teeth with tooth mobility °2. Overhanging dental composite restorations of Class V were detected at the subgingival areas of 15, 16, and 17. Radiographic results show vertically and horizontally alveolar bone loss. This case report is aimed to describe the management of periodontal tissue destruction as a result of overhanging dental composite restorations. Scaling and root planing were conducted as the initial therapy. The periodontal surgery was performed a week after the initial therapy. A full-thickness flap design with sulcular incision from 14 to 18 was made before the pocket curretage and necrotic tissue debridement along with restoration recontouring. The flap was sutured with simple suture technique. Periodontal dressing was packed for a week. Antibiotics, analgetics and antiinflammatory drugs were prescribed per orally. There was no history of pain a week after the surgical procedure. Tooth mobility was decreased to °1 and the periodontal pocket was reduced to 3 mm. Overhanging dental restorations may lead to periodontal tissue destruction. The subgingivally placement of those restorations should consider the health of periodontal tissues.

Management of large class II lesions in molars: how to restore and when to perform surgical crown lengthening?

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Ana Belén Dablanca-Blanco

2017-08-01

Full Text Available The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect and the management of the cavity margin, such as the need for deep margin elevation (DME or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.

Fractographic features of glass-ceramic and zirconia-based dental restorations fractured during clinical function.

Science.gov (United States)

Oilo, Marit; Hardang, Anne D; Ulsund, Amanda H; Gjerdet, Nils R

2014-06-01

Fractures during clinical function have been reported as the major concern associated with all-ceramic dental restorations. The aim of this study was to analyze the fracture features of glass-ceramic and zirconia-based restorations fractured during clinical use. Twenty-seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass-ceramic restorations and 13 zirconia-based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to the most coronally placed curvature of the margin. Three cases of occlusal chipping were found. The margin of dental all-ceramic single-tooth restorations was the area of fracture origin. The fracture features were similar for zirconia, glass-ceramic, and alumina single-tooth restorations. Design features seem to be of great importance for fracture initiation. © 2014 Eur J Oral Sci.

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

Science.gov (United States)

Son, Mee-Kyoung; Jang, Hyun-Seon

2011-12-01

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

Factors Affecting the Quality of Tooth Enamel for In Vivo EPR-Based Retrospective Biodosimetry.

Science.gov (United States)

Desmet, Céline M; Levêque, Philippe; Gallez, Bernard

2016-12-01

In vivo electron paramagnetic resonance biodosimetry on tooth enamel is likely to be an important technology for triage of overexposed individuals after a major radiological incident. The accuracy and robustness of the technique relies on various properties of the enamel such as the geometry of the tooth, the presence of restorations, whitening treatments or exposition to sunlight. Those factors are reviewed, and their influence on dosimetry specifically for triage purposes is discussed. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

THE INFLUENCE OF SHRINKAGE AND MOISTURE DIFFUSION ON IDEALIZED TOOTH STRUCTURE INVOLVING DEBONDING DAMAGE

Institute of Scientific and Technical Information of China (English)

FanJianping; TangChak-Yin

2005-01-01

This study highlights the joint effect of early polymerization shrinkage and longtermmoisture diffusion on the behavior of the restoration-tooth structure. The interphase debonding between particle and polymer resin in dental composite is taken into account by introducing the damage variable. The idealized model is designed and constructed for representing the restorationtooth structure, which consists of enamel, dentin, composite and interphase, each considered as homogenous material. The simulation is carried out using the general-purpose finite element software package, ABAQUS incorporated with a user subroutine for definition of damaged material behavior. The influence of Young's moduli of composite and interphase on stress and displacement is discussed. The compensating effect of water sorption on the polymerization shrinkage is examined with and without involving damage evolution. A comparison is made between the influence of hyper-, equi- and hypo-water sorption. Interfacial failure in the specific regions as well as cuspal movement has been predicated. The damage evolving in dental composite reduces the rigidity of composite, thus in turn reducing consequent stress and increasing consequent displacement. The development of stresses at the restoration-tooth interface can have a detrimental effect on the longevity of a restoration.

Repair Responses of Dental Pulp to Tooth Injury and Biological Properties of Dentin-pulp Complex

OpenAIRE

大島, 勇人; Ohshima, Hayato

2004-01-01

Regeneration-the creation of a new tissue after the original one has been lost-is the fundamental biological capability in an organism. Numerous organs are considered to contain stem cells referred to as adult stem cells, even in the adult. Adult stem cells can give rise to a limited set of adult tissue types. In the field of clinical dentistry, it is well-known that the dentin-pulp complex is capable of repair after tooth injuries such as tooth replantation/transplantation or restorative pro...

Spectrophotometric Evaluation of the Pulpal Peroxide Levels in Intact and Restored Teeth - An Invitro Study.

Science.gov (United States)

Patri, Gaurav; Acharya, Gourismita; Agrawal, Pratik; Panda, Vijeta

2016-08-01

Hydrogen peroxide (30%) is a commonly used "in office" bleaching agent. Deleterious effects of hydrogen peroxide on the pulp have been observed. The present study was conducted with the aim to evaluate the penetration of 30% hydrogen peroxide into the pulp chamber through intact teeth and through the surface of teeth, restored with either hybrid composite or Resin Modified Glass Ionomer Cement (RMGIC). Sixty extracted human maxillary central incisors were selected and divided into six groups. Two groups were restored with hybrid composite resin and two with RMGIC, while two groups were left intact. The teeth with acetate buffer solution in their pulp cavity were then immersed in either 30% hydrogen peroxide or distilled water depending upon the group, for 60 minutes at 37°C. Then horseradish peroxidase and leucocrystal violet were added to the acetate buffer solution present in the pulp chamber after it was transferred to a test tube and the optical density of the resultant blue solution obtained was measured spectrophotometrically. The data obtained were analyzed using one way ANOVA and Student's t-test. The data obtained established that hydrogen peroxide penetrated into the pulp from the bleaching agent used. Hydrogen peroxide (30%) showed the highest pulpal peroxide level in teeth restored with RMGIC followed by teeth restored with hybrid composite resin and the least amount of penetration was observed in intact teeth. The amount of peroxide penetration into the tooth is more through restored tooth than intact tooth and is also dependant on the type of restorative materials used.

Endodontic treatment and esthetic management of a primary double tooth with direct composite using silicone buildup guide

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Vinaya Kumar Kulkarni

2012-01-01

Full Text Available Gemination and fusion are morphological dental anomalies, characterized by the formation of a clinically wide tooth. Gemination occurs when one tooth bud tries to divide, while fusion occurs if two buds unite. The terms double teeth, double formation, conjoined teeth, geminifusion, vicinifusion and dental twinning are often used to describe fusion and gemination. Double teeth are associated with clinical problems such as poor esthetics, spacing problems and caries susceptibility. Management of such cases requires a comprehensive knowledge of the clinical entity as well as the problems associated with it. This report presents a case of primary double tooth in a 6-year-old boy involving maxillary left central incisor. The anomalous tooth was carious and pulpally involved. This was treated conservatively by endodontic treatment and esthetic rehabilitation was done with direct composite restoration using a silicone buildup guide. The treated tooth was followed up until exfoliation.

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

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Tiago Borges

2012-09-01

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

Autogenous tooth transplantation for replacing a lost tooth: case reports

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Ji-Youn Kang

2013-02-01

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

Restorative Glass : Reversible, discreet restoration using structural glass components

NARCIS (Netherlands)

Oikonomopoulou, F.; Bristogianni, T.; Barou, L.; van Hees, R.P.J.; Nijsse, R.; Veer, F.A.; Henk, Schellen; van Schijndel, Jos

2016-01-01

The application of structural glass as the principal material in restoration and conservation practices is a distinguishable, yet discreet approach. The transparency of glass allows the simultaneous perception of the monument at both its original and present condition, preserving its historical and

Use of the Empress all-ceramic restoration system.

Science.gov (United States)

Goulet, M K

1997-01-01

New dental materials and techniques have been introduced in the past few years to fabricate aesthetic ceramic restorations with improved strength, biocompatibility, resistance to wear, and better fit. Aesthetic concerns and increasing demand for tooth-colored posterior restorations have led to a number of all-ceramic restorations such as IPS Empress (Ivoclar-Williams, Amherst, NY). The Empress system offers superior aesthetics and physical properties. New generation ceramics along with the current adhesive techniques have resulted in the ability to provide higher strength, therefore indicating crowns for posterior restorations as well. These materials are being used more frequently and in more extensive oral prosthetic rehabilitations such as the case that will be presented. We discuss the different properties and advantages of IPS Empress.

[Cermet cements for milk tooth fillings. Preliminary results].

Science.gov (United States)

Hickel, R; Petschelt, A; Voss, A

1989-06-01

106 Ketac-Silver fillings in deciduous molars were reevaluated after 1 to 3.3 years, i.e. 25 month on the average. About 90% of 50 occlusal fillings and about 84% of 56 multisurface restorations were unchanged. Without claiming statistical evidence for their conclusiveness, we consider these results as an indication that cermet cements are a useful alternative to amalgam fillings in deciduous teeth, particularly since the life of these fillings is limited to the time until the milk tooth is physiologically lost.

Three-year clinical follow-up of posterior teeth restored with leucite-reinforced ips empress onlays and partial veneer crowns.

Science.gov (United States)

Murgueitio, Rafael; Bernal, Guillermo

2012-07-01

The aim of this study was to analyze the survival rate and failure mode of IPS leucite-reinforced ceramic onlays and partial veneer crowns regarding thickness under the following clinical conditions: vital versus nonvital teeth, tooth location, and type of opposing dentition. Teeth were prepared according to established guidelines for ceramic onlays and partial veneer crowns. Before cementation, the restorations were measured for occlusal thickness at the central fossa, mesial, and distal marginal ridges, and functional and nonfunctional cusps. A total of 210 ceramic restorations were cemented in 99 patients within a mean observation period of 2.9 ± 1.89 years. The mode of failure was classified and evaluated as (1) adhesive, (2) cohesive, (3) combined failure, (4) decementation, (5) tooth sensitivity, and (6) pulpal necrosis. Kaplan, log-rank, and Cox regression tests were used for statistical analysis. The failure rate was 3.33% (7/210). Increased material thickness produced less probability of failures. Vital teeth were less likely to fail than nonvital teeth. Second molars were five times more susceptible to failure than first molars. Tooth sensitivity postcementation and the type of opposing dentition were not statistically significant in this study. In this study, thickness of the restorations, tooth vitality, and location of teeth in the dental arch influenced restoration failures. © 2012 by the American College of Prosthodontists.

Clinical, radiographic, and histological observation of a human immature permanent tooth with chronic apical abscess after revitalization treatment.

Science.gov (United States)

Shimizu, Emi; Ricucci, Domenico; Albert, Jeffrey; Alobaid, Adel S; Gibbs, Jennifer L; Huang, George T-J; Lin, Louis M

2013-08-01

Revitalization procedures have been widely used for the treatment of immature permanent teeth with apical periodontitis. The treatment procedures appear to be capable of encouraging continued root development and thickening of the canal walls. The nature of tissues formed in the canal space and at the root apex after revitalization has been shown histologically in several animal studies; similar studies in humans were recently reported. A 9-year-old boy had a traumatic injury to his upper anterior teeth. Tooth #9 suffered a complicated crown fracture with a pulp exposure, which was restored with a composite resin. The tooth developed a chronic apical abscess. Revitalization procedures were performed on tooth #9 because it was an immature permanent tooth with an open apex and thin canal walls. Twenty-six months after revitalization, the tooth had a horizontal crown fracture at the cervical level and could not be restored. The tooth was extracted and processed for routine histological and immunohistochemical examination to identify the nature of tissues formed in the canal space. Clinically and radiographically, the revitalization of the present case was successful because of the absence of signs and symptoms and the resolution of periapical lesion as well as thickening of the canal walls and continued root development. The tissue formed in the canal was well-mineralized cementum- or bone-like tissue identified by routine histology and immunohistochemistry. No pulp-like tissue characterized by the presence of polarized odontoblast-like cells aligning dentin-like hard tissue was observed. The tissues formed in the canal of revitalized human tooth are similar to cementum- or bone-like tissue and fibrous connective tissue. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Accuracy of single-tooth restorations based on intraoral digital and conventional impressions in patients.

Science.gov (United States)

Boeddinghaus, Moritz; Breloer, Eva Sabina; Rehmann, Peter; Wöstmann, Bernd

2015-11-01

The purpose of this clinical study was to compare the marginal fit of dental crowns based on three different intraoral digital and one conventional impression methods. Forty-nine teeth of altogether 24 patients were prepared to be treated with full-coverage restorations. Digital impressions were made using three intraoral scanners: Sirona CEREC AC Omnicam (OCam), Heraeus Cara TRIOS and 3M Lava True Definition (TDef). Furthermore, a gypsum model based on a conventional impression (EXA'lence, GC, Tokyo, Japan) was scanned with a standard laboratory scanner (3Shape D700). Based on the dataset obtained, four zirconia copings per tooth were produced. The marginal fit of the copings in the patient's mouth was assessed employing a replica technique. Overall, seven measurement copings did not fit and, therefore, could not be assessed. The marginal gap was 88 μm (68-136 μm) [median/interquartile range] for the TDef, 112 μm (94-149 μm) for the Cara TRIOS, 113 μm (81-157 μm) for the laboratory scanner and 149 μm (114-218 μm) for the OCam. There was a statistically significant difference between the OCam and the other groups (p < 0.05). Within the limitations of this study, it can be concluded that zirconia copings based on intraoral scans and a laboratory scans of a conventional model are comparable to one another with regard to their marginal fit. Regarding the results of this study, the digital intraoral impression can be considered as an alternative to a conventional impression with a consecutive digital workflow when the finish line is clearly visible and it is possible to keep it dry.

Autogenous tooth transplantation: an alternative to replace extracted tooth

Directory of Open Access Journals (Sweden)

David B. Kamadjaja

2015-09-01

Full Text Available Background: The gold standard treatment to replace missing tooth is dental implants, however, in certain cases, such as in young patients its placement is contraindicated. Autogenous tooth transplantation, which has been widely done in Scandinavian countries for many years, may become a good alternative to overcome this problem. Purpose: This article attempted to provide information about the indication, treatment planning, surgical technique and the successful result of autogenous tooth transplantation. Case: A fifteen year old male patient presented with large caries and periapical disease of his lower left first molar, which was partially erupted and the roots was not fully formed in radiograph. Case management: Autogenous tooth transplantation procedure was performed consisting of extraction of #36, odontectomy of #38 followed by its implantation to socket #36 and fixation of the transplanted tooth to the adjacent teeth. Post operative evaluation was done on regular basis within 18 months period. There was no complaint, the tooth was clinically stable and no evidence of periodontal problem. Serial radiographs showed healing of alveolar bone and periodontal tissue, and the complete root formation was evident by 18 months post operatively. Conclusion: Autogenous tooth transplantation is a potential alternative to replace extracted tooth. Provided that the case be properly planned and operation carefully performed, successful result of this treatment can be achieved.

Tooth engineering: searching for dental mesenchymal cells sources.

Directory of Open Access Journals (Sweden)

Laetitia eKeller

2011-03-01

Full Text Available The implantation of cultured re-associations between embryonic dental mesenchymal cells and epithelial cells from mouse molars at ED14 allowed making full teeth with crown, root, periodontal ligament fibers and bone. Although representing valuable tools to set up methodologies embryonic cells are not easily available. This work thus aimed to replace the embryonic cells by dental mesenchymal cell lines or cultured expanded embryonic cells, and to test their ability to mediate tooth development in vitro when re-associated with a competent dental epithelium. Histology, immunostaining and RT-PCR allowed getting complementary sets of results. Two different immortalized cell lines from ED18 dental mesenchyme failed in mediating tooth formation. The potentialities of embryonic dental mesenchymal cells decreased from ED14 to ED16 and were lost at ED18. This is likely related to a change in the mesenchymal cell phenotype and/or populations during development. Attempts to cultivate ED14 or ED16 embryonic dental mesenchymal cells prior to re-association led to the loss of their ability to support tooth development. This was accompanied by a down-regulation of Fgf3 transcription. Supplementation of the culture medium with FGF2 allowed restoring Fgf3 expression, but not the ability of mesenchymal cells to engage in tooth formation. Altogether, these observations suggest that a competent cell population exists in the dental mesenchyme at ED14, progressively decreases during development, and cannot as such be maintained in vitro. This study evidenced the need for specific conditions to maintain the ability of dental mesenchymal cells to initiate whole tooth formation, when re-associated with an odontogenic epithelium. Efforts to improve the culture conditions will have to be combined with attempts to characterize the competent cells within the dental mesenchyme.

Retrospective individual dosimetry using EPR of tooth enamel

International Nuclear Information System (INIS)

Skvortzo, V.; Ivannikov, A.; Stepanenko, V.; Wieser, A.; Bougai, A.; Brick, A.; Chumak, V.; Radchuk, V.; Repin, V.; Kirilov, V.

1996-01-01

The results of joint investigations (in the framework of ECP-10 program) aimed on the improvement of the sensitivity and accuracy of the procedure of dose measurement using tooth enamel EPR spectroscopy are presented. It is shown, what the sensitivity of method may be increased using special physical-chemical procedure of the enamel samples treatment, which leads to the reducing of EPR signal of organic components in enamel. Tooth diseases may have an effect on radiation sensitivity of enamel. On the basis of statistical analysis of the results of more then 2000 tooth enamel samples measurements it was shown, what tooth enamel EPR spectroscopy gives opportunity to register contribution into total dose, which is caused by natural environmental radiation and by radioactive contamination. EPR response of enamel to ultraviolet exposure is investigated and possible influences to EPR dosimetry is discussed. The correction factors for EPR dosimetry in real radiation fields are estimated

Finite-temperature symmetry restoration in the four-dimensional Φ4 model with four components

International Nuclear Information System (INIS)

Jansen, K.

1990-01-01

The finite-temperature symmetry restoration in the four-dimensional φ 4 theory with four components and with an infinite self-coupling is studied by means of Monte Carlo simulations on lattices with time extensions L t =4,5,6 and space extensions 12 3 -28 3 . The numerical calculations are done by means of the Wolff cluster algorithm which is very efficient for simulations near a phase transition. The numerical results are in good agreement with an improved one-loop expansion and with the 1/N-expansion, indicating that in the electroweak theory the symmetry restoration temperature T sr is about 350 GeV. (orig.)

APPLICATION OF 3D DIGITAL SCANNING AND CAD/CAM SYSTEMS FOR ZIRCONIA INDIRECT RESTORATIONS

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Mariela Tsanova

2016-09-01

Full Text Available Object: To study the CAD/CAM systems’ possibilities for manufacturing Zirconia indirect restorations for restoring vital, vastly devastated teeth. Material and methods: Five patients with vital, heavily destroyed molars were included in the clinical study. The teeth were prepared according to requirements for Zirconia restorations. The impressions were taken with 3D intraoral scanner. The acquired data is transmitted electronically for designing the future restoration by the CAD software. After designing, the restoration is milled by the CAM module and sintered, according to a specially projected programme in accordance with the manufacturing demands. After clinical check-up, the restorations are glazed, air-blasted and cemented. Results: Setting up an individual protocol for working with CAD/CAM systems for restoring vital, severely devastated teeth with Zirconia indirect restorations. A research is made on 3D digital scanning, occlusal and proximal modeling, virtual articulation, analyzing the incline of the cavity walls, the thickness of the restoration and the possibilities for restoring the anatomy of the tooth according to patient’s individual characteristics of the teeth’s arch. Conclusion: The scanning and design process should be evaluated with the same quality control as when using traditional methods. The CAD software requires excellent preparation of the tooth cavity and digital scanning. This is the reason why these systems require a thorough understanding of CAD/CAM calibration and parameters of the product to be clinically acceptable. Once understood, CAD/CAM dentistry can create detailed and accurate restorations that function and perform with great success and longevity.

Conservative restoration of a traumatically involved central incisor.

Science.gov (United States)

Bassett, Joyce

2012-04-01

The use of a direct composite material known for excellent polishability, polish retention, and wear resistance is described in this case of a fractured central incisor restoration. The method used enabled the clinician to conserve tooth structure and maintain full control of the outcome while creating an esthetically imperceptible, reliable, and durable restoration for a young male patient. Emphasized in this case are the techniques of layering, contouring, and polishing of a nanocomposite used to maximize esthetics and meet patient expectations. To further ensure imperceptibility, the author recommends first facilitating color shade selection for both body and dentin-especially in two-shade or multiple-shade restorations-by placing the composite in its planned area of the restoration and curing it in its proper thickness to allow a preview and recipe map.

Influence of dental restorations and mastication loadings on dentine fatigue behaviour: Image-based modelling approach.

Science.gov (United States)

Vukicevic, Arso M; Zelic, Ksenija; Jovicic, Gordana; Djuric, Marija; Filipovic, Nenad

2015-05-01

The aim of this study was to use Finite Element Analysis (FEA) to estimate the influence of various mastication loads and different tooth treatments (composite restoration and endodontic treatment) on dentine fatigue. The analysis of fatigue behaviour of human dentine in intact and composite restored teeth with root-canal-treatment using FEA and fatigue theory was performed. Dentine fatigue behaviour was analysed in three virtual models: intact, composite-restored and endodontically-treated tooth. Volumetric change during the polymerization of composite was modelled by thermal expansion in a heat transfer analysis. Low and high shrinkage stresses were obtained by varying the linear shrinkage of composite. Mastication forces were applied occlusally with the load of 100, 150 and 200N. Assuming one million cycles, Fatigue Failure Index (FFI) was determined using Goodman's criterion while residual fatigue lifetime assessment was performed using Paris-power law. The analysis of the Goodman diagram gave both maximal allowed crack size and maximal number of cycles for the given stress ratio. The size of cracks was measured on virtual models. For the given conditions, fatigue-failure is not likely to happen neither in the intact tooth nor in treated teeth with low shrinkage stress. In the cases of high shrinkage stress, crack length was much larger than the maximal allowed crack and failure occurred with 150 and 200N loads. The maximal allowed crack size was slightly lower in the tooth with root canal treatment which induced somewhat higher FFI than in the case of tooth with only composite restoration. Main factors that lead to dentine fatigue are levels of occlusal load and polymerization stress. However, root canal treatment has small influence on dentine fatigue. The methodology proposed in this study provides a new insight into the fatigue behaviour of teeth after dental treatments. Furthermore, it estimates maximal allowed crack size and maximal number of cycles for a

Practitioner, patient and carious lesion characteristics associated with type of restorative material

DEFF Research Database (Denmark)

Makhija, Sonia K; Gordan, Valeria V; Gilbert, Gregg H

2011-01-01

The authors conducted a study to identify factors associated with the materials that dentists in The Dental Practice-Based Research Network (DPBRN) use when placing the first restoration on permanent posterior tooth surfaces....

Tooth development in Ambystoma mexicanum: phosphatase activities, calcium accumulation and cell proliferation in the tooth-forming tissues.

Science.gov (United States)

Wistuba, Joachim; Ehmcke, Jens; Clemen, Günter

2003-06-01

Prerequisites of tooth formation, cell proliferation in the tooth-forming tissues, calcium accumulation and the enzymatic activities of alkaline (ALP) and acid phosphatases (ACP) were investigated by immunohistochemical and histochemical methods in various developmental stages of the Mexican Axolotl, Ambystoma mexicanum. During the growth of replacement teeth, the tooth-forming tissues continually recruit cells from the surrounding regions. The basal layer of the oral epithelium, the dental lamina and sometimes even the outer enamel epithelium provide cells for the differentiated inner enamel epithelium, in which the active ameloblasts are localized. The differentiating odontoblasts are derived from proliferating cells situated basally to the replacement teeth in the mesenchymal tissue. When differentiation has started and the cells have become functional, proliferative activity can no longer be observed. Calcium is accumulated close to the site of mineralization in the inner enamel epithelium and in the odontoblasts as it is in mammals, elasmobranchii and teleostei. The activities of ACP and ALP related to the mineralization of the replacement teeth are separated spatially and not sequentially as they are in mammals. However, the results indicate a similar function of these enzymatic components in relation to tooth formation and maturation of mineral deposition. Most of the substantial processes related to tooth formation reported from other vertebrates occur in a manner similar to that in Ambystoma mexicanum, but there also seem to be basic mechanisms present that are realised in a unique way in this urodele.

Zirconia implants and peek restorations for the replacement of upper molars

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José María Parmigiani-Izquierdo

2017-02-01

Full Text Available Abstract Background One of the disadvantages of the zirconia implants is the lack of elasticity, which is increased with the use of ceramic or zirconia crowns. The consequences that could result from this lack of elasticity have led to the search for new materials with improved mechanical properties. Case presentation A patient who is a 45-year-old woman, non-smoker and has no medical record of interest with a longitudinal fracture in the palatal root of molar tooth 1.7 and absence of tooth 1.6 was selected in order to receive a zirconia implant with a PEEK-based restoration and a composite coating. The following case report describes and analyses treatment with zirconia implants in molars following a flapless surgical technique. Zirconia implants are an alternative to titanium implants in patients with allergies or who are sensitive to metal alloys. However, one of the disadvantages that they have is their lack of elasticity, which increases with the use of ceramic or zirconia crowns. The consequences that can arise from this lack of elasticity have led to the search for new materials with better mechanical properties to cushion occlusal loads. PEEK-based restoration in implant prosthetics can compensate these occlusal forces, facilitating cushioning while chewing. Conclusion This procedure provides excellent elasticity and resembles natural tooth structure. This clinical case suggests that PEEK restorations can be used in zirconia implants in dentistry.

The use of a reinforced glass-ionomer cermet for the restoration of primary molars: a clinical trial.

Science.gov (United States)

Kilpatrick, N M; Murray, J J; McCabe, J F

1995-09-09

The development of adhesive restorative materials has led to more conservative cavity design with greater reliance being placed upon the bond of a material with tooth tissue for retention of the restoration. Glass-ionomer cements may offer particular advantages but have yet to achieve the durability reported for amalgam. This study reports on the results of a 2.5-year prospective clinical trial comparing the durability of two glass-ionomer cements, a conventional material (Ketac Fil) and a metal reinforced cermet (Ketac Silver) in the restoration of Class II lesions in primary molars. Forty-six pairs of restorations were assessed in 37 children. The failure rate of Ketac Fil, 23%, was significantly lower than that of Ketac Silver, 41% (P < 0.05). The median survival time of the Ketac Fil restorations was significantly greater, 25.3 months, than that of the Ketac Silver restorations, 20.3 months (P < 0.05). These values may be an underestimate of the true longevity of both restoration types as many of the restorations survived intact at the censor date. Neither the age of the child nor the tooth restored influenced the durability of the restoration. The deterioration in both marginal integrity and anatomic form of the Ketac Silver restorations was significantly greater than the Ketac Fil restorations (P < 0.05). The durability of Ketac Silver was such that it cannot be recommended for use in restoring carious primary molars.

Immediate loading and customized restoration of a single implant in the maxillary esthetic zone : A clinical report

NARCIS (Netherlands)

den Hartog, Laurens; Raghoebar, Gerry M.; Stellingsma, Kees; Meijer, Henny J. A.

2009-01-01

The replacement of a single missing anterior tooth with an implant-supported crown Is a demanding therapy. This report describes a treatment in which an anterior maxillary implant was immediately restored with a provisional restoration. During the provisional phase, an optimal emergence profile was

A pin-assisted retention technique for resin-bonded restorations.

Science.gov (United States)

Miara, P; Touati, B

1992-09-01

The value of pins for auxiliary retention has been demonstrated many times. The use of pins with resin-bonded restorations allows for improved aesthetics and less tooth reduction while increasing resistance to dislodging forces. Clinical and technical procedures for resin-bonded bridges with pin-assisted retention are presented.

Orthodontic extrusion of subgingivally fractured tooth using a removable appliance: an alternative treatment to reestablish biological width.

Science.gov (United States)

Verma, Kanika Gupta; Juneja, Suruchi; Kumar, Sandeep; Goyal, Tanya

2014-01-01

Restoration of a traumatically injured tooth presents a clinical challenge for a predictable aesthetic outcome. This case report describes a multidisciplinary approach of a subgingivally fractured permanent maxillary central incisor. A removable orthodontic appliance was used for orthodontic extrusion of root, and surgical gingival recontouring was done with electrocautery to reestablish the biological width. Form and function were restored establishing biological width and esthetics was repaired with porcelain fused to metal crown.

Fracture mode during cyclic loading of implant-supported single-tooth restorations

DEFF Research Database (Denmark)

Hosseini, Mandana; Kleven, Erik; Gotfredsen, Klaus

2012-01-01

restorations of zirconia abutment-retained crowns with zirconia copings veneered with glass-ceramics (n=8) and feldspathic ceramics (n=8). The control group was composed of 16 metal ceramic restorations of titanium abutment-retained crowns with gold alloy copings veneered with glass (n=8) and feldspathic...... ceramics (n=8). The palatal surfaces of the crowns were exposed to cyclic loading of 800 N with a frequency of 2 Hz, which continued to 4.2 million cycles or until fracture of the copings, abutments, or implants. The number of cycles and the fracture modes were recorded. The fracture modes were analyzed...

Optimal mechanical design of anatomical post-systems for endodontic restoration.

Science.gov (United States)

Maceri, Franco; Martignoni, Marco; Vairo, Giuseppe

2009-02-01

This paper analyses the mechanical behaviour of a new reinforced anatomical post-systems (RAPS) for endodontic restoration. The composite restorative material (CRM) completely fills the root canal (as do the commonly used cast metal posts) and multiple prefabricated composite posts (PCPs) are employed as reinforcements. Numerical simulations based on 3D linearly elastic finite element models under parafunctional loads were performed in order to investigate the influence of the stiffness of the CRM and of the number of PCPs. Periodontal ligament effects were taken into account using a discretised anisotropic nonlinearly elastic spring system, and the full discrete model was validated by comparing the resulting stress fields with those obtained with conventional restorations (cast gold-alloy post, homogeneous anatomical post and cemented single PCP) and with the natural tooth. Analysis of the results shows that stresses at the cervical/middle region decrease as CRM stiffness increases and, for large and irregular root cavities that apical stress peaks disappear when multiple PCPs are used. Accordingly, from a mechanical point of view, an optimal RAPS will use multiple PCPs when CRM stiffness is equal to or at most twice that of the dentin. This restorative solution minimises stress differences with respect to the natural tooth, mechanical inhomogeneities, stress concentrations on healthy tissues, volumes subject to shrinkage phenomena, fatigue effects and risks of both root fracture and adhesive/cohesive interfacial failure.

Rapid and selective removal of composite from tooth surfaces with a 9.3 µm CO2 laser using spectral feedback.

Science.gov (United States)

Chan, Kenneth H; Hirasuna, Krista; Fried, Daniel

2011-09-01

Dental composite restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants, or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study, a carbon dioxide laser operating at 9.3-µm with a pulse duration of 10-20-microsecond and a pulse repetition rate of ∼200 Hz was integrated with a galvanometer based scanner and used to selectively remove composite from tooth surfaces. Spectra of the plume emission were acquired after each laser pulse and used to differentiate between the ablation of dental enamel or composite. Microthermocouples were used to monitor the temperature rise in the pulp chamber during composite removal. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser beam was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove composite from tooth buccal and occlusal surfaces with minimal damage to the underlying sound enamel and without excessive heat accumulation in the tooth. This study demonstrated that composite can be selectively removed from tooth surfaces at clinically relevant rates using a CO(2) laser operating at 9.3-µm with high pulse repetition rates with minimal heat deposition and damage to the underlying enamel. Copyright © 2011 Wiley-Liss, Inc.

The influence of hyperthyroidism on implant restoration treatment outcome

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Suhandi Sidjaja

2006-09-01

Full Text Available There is limited information about bone implant restoration treatment on edentulous patient with hyperthyroidism. This clinical report is presenting the making of dental bone implant restoration on patient with hyperthyroidism history. A 60 years old male patient with hyperthyroidism came to Prosthodontic Clinic Faculty of Dentistry University of Indonesia to improve his ailing denture. After comprehensive evaluation we treated the patient with Implant-Tissue-Supported Overdenture (4 Implants for rehabilitating upper edentulous jaw, and 2 Implant-Tooth-Supported Fixed Partial Denturesfor rehabilitating Kennedy class II lower edentulous jaw respectively. Short term clinical and radiographic evaluation based on Buser’s criteria showed positive result. (Med J Indones 2006; 15:191-5Keywords: Hyperthyroidsm, implant restoration

Demographic, socioeconomic, and behavioral factors affecting patterns of tooth decay in the permanent dentition: principal components and factor analyses.

Science.gov (United States)

Shaffer, John R; Polk, Deborah E; Feingold, Eleanor; Wang, Xiaojing; Cuenco, Karen T; Weeks, Daniel E; DeSensi, Rebecca S; Weyant, Robert J; Crout, Richard; McNeil, Daniel W; Marazita, Mary L

2013-08-01

Dental caries of the permanent dentition is a multifactorial disease resulting from the complex interplay of endogenous and environmental risk factors. The disease is not easily quantitated due to the innumerable possible combinations of carious lesions across individual tooth surfaces of the permanent dentition. Global measures of decay, such as the DMFS index (which was developed for surveillance applications), may not be optimal for studying the epidemiology of dental caries because they ignore the distinct patterns of decay across the dentition. We hypothesize that specific risk factors may manifest their effects on specific tooth surfaces leading to patterns of decay that can be identified and studied. In this study, we utilized two statistical methods of extracting patterns of decay from surface-level caries data to create novel phenotypes with which to study the risk factors affecting dental caries. Intra-oral dental examinations were performed on 1068 participants aged 18-75 years to assess dental caries. The 128 tooth surfaces of the permanent dentition were scored as carious or not and used as input for principal components analysis (PCA) and factor analysis (FA), two methods of identifying underlying patterns without a priori knowledge of the patterns. Demographic (age, sex, birth year, race/ethnicity, and educational attainment), anthropometric (height, body mass index, waist circumference), endogenous (saliva flow), and environmental (tooth brushing frequency, home water source, and home water fluoride) risk factors were tested for association with the caries patterns identified by PCA and FA, as well as DMFS, for comparison. The ten strongest patterns (i.e. those that explain the most variation in the data set) extracted by PCA and FA were considered. The three strongest patterns identified by PCA reflected (i) global extent of decay (i.e. comparable to DMFS index), (ii) pit and fissure surface caries and (iii) smooth surface caries, respectively. The

Restorative Management of Intrinsic and Extrinsic Dental Erosion.

Science.gov (United States)

Al-Salehi, Samira Kathryn

2014-12-01

The restorative management of tooth surface loss is highlighted through the presentation of two advanced cases of dental erosion. On presentation, the causes of the dental erosion in both patients had been previously diagnosed and stopped. The first patient was a 67 year old with intrinsic erosion and an element of attrition where a multidisciplinary approach was used. The other, a 17 year old patient with extrinsic erosion managed via adhesive restorations. Adhesive techniques are a relatively simple, effective and conservative method for the treatment of dental erosion. The two treatment modalities (conventional versus contemporary) are compared and discussed.

Tooth preparations for complete crowns: an art form based on scientific principles.

Science.gov (United States)

Goodacre, C J; Campagni, W V; Aquilino, S A

2001-04-01

No recent literature has reviewed the current scientific knowledge on complete coverage tooth preparations. This article traces the historic evolution of complete coverage tooth preparations and identifies guidelines for scientific tooth preparations. Literature covering 250 years of clinical practice was reviewed with emphasis on scientific data acquired during the last 50 years. Both a MEDLINE search and an extensive manual search were used to locate relevant articles written in English in the last 50 years. Teeth should be prepared so that they exhibit the following characteristics: 10 to 20 degrees of total occlusal convergence, a minimal occlusocervical dimension of 4 mm for molars and 3 mm for other teeth, and an occlusocervical-to-faciolingual dimension ratio of 0.4 or greater. Facioproximal and linguoproximal line angles should be preserved whenever possible. When the above features are missing, the teeth should be modified with auxiliary resistance features such as axial grooves or boxes, preferably on proximal surfaces. Finish line selection should be based on the type of crown/retainer, esthetic requirements, ease of formation, and personal experience. Expectations of enhanced marginal fit with certain finish lines could not be validated by recent research. Esthetic requirements and tooth conditions determine finish line locations relative to the gingiva, with a supragingival location being more acceptable. Line angles should be rounded, and a reasonable degree of surface smoothness is desired. Nine scientific principles have been developed that ensure mechanical, biologic, and esthetic success for tooth preparation of complete coverage restorations.

Composite Replacement of Amalgam Restoration Versus Freshly Cut Dentin: An In Vitro Microleakage Comparison.

Science.gov (United States)

Redwan, H; Bardwell, D N; Ali, A; Finkelman, M; Khayat, S; Weber, H-P

2016-01-01

The aim of this study was to evaluate the microleakage of the composite restorations when bonded to tooth structure previously restored with amalgam material compared with that of freshly cut dentin. Thirty intact, extracted intact human molars were mounted in autopolymerizing acrylic resin. Class II box preparations were prepared on the occluso-proximal surfaces of each tooth (4-mm bucco-lingual width and 2-mm mesio-distal depth) with the gingival cavosurface margin 1 mm above the CEJ. Each cavity was then restored using high copper amalgam restoration (Disperalloy, Dentsply) and then thermocycled for 10,000 thermal cycles. Twenty-five of the amalgam restorations were then carefully removed and replaced with Filtek Supreme Ultra Universal (3M ESPE); the remaining five were used for scanning electron microscopy and energy dispersive x-ray spectroscopy analysis. A preparation of the same dimensions was performed on the opposite surface of the tooth and restored with composite resin and thermocycled for 5000 thermal cycles. Twenty samples were randomly selected for dye penetration testing using silver nitrate staining to detect the microleakage. The specimens were analyzed with a stereomicroscope at a magnification of 20×. All of the measurements were done in micrometers; two readings were taken for each cavity at the occlusal and proximal margins. Two measurements were taken using a 0-3 scale and the percentage measurements. Corrosion products were not detected in either group (fresh cut dentin and teeth previously restored with amalgam). No statistically significant difference was found between the microleakage of the two groups using a 0-3 scale at the occlusal margins (McNemar test, p=0.727) or proximal margins (Wilcoxon signed-rank test, p=0.174). No significance difference was found between the two groups using the percentage measurements and a Wilcoxon signed-rank test at either the occlusal (p=0.675) or proximal (p=0.513) margins. However, marginal

Treatment of abraded teeth using metal free ceramics and conventional metal-ceramic restorations

Directory of Open Access Journals (Sweden)

Bošković Mirjana V.

2012-01-01

Full Text Available Introduction. Contemporary reconstructive dentistry is considered to be a bioesthetic discipline, the study of the beauty of living creatures in their original form and functions. A discussion of esthetic dentistry, the sophisticated artificial restorations in the patient mouth, hardly discernible to an observer or expert eye, implies a whole series of qualities. Damage of hard tooth-tissue, which is not caused by caries, is a physiological process present throughout the whole life, but some factors can bring about great losses of the hard tissue. This damage can be caused by a combination of different etiological factors, such as genetical and functional ones. Case report. A patient is coming in dental surgery complaining of a large damage of the hard-tooth tissue, ugly appearance of his teeth, speech dysfunction and masticatory problems. An intraoral view shows the presence of a large teeth-abrasion. The treatment plan simplified the treatment with a combination of metal-ceramic restorations and a new ceramic system IPS e.max (Ivoclar Vivadentm Schaan, Liechtenstien. Conclusion. In this clinical case with presented abrasion the treatment was presented using all-ceramic restorations and classical metal-ceramic restorations to establish good health, function and estehetic. The use of restorations based on zirconium (IPS e.max ZirPress, Ivoclar Vivadent, Schaan, Liechtenstein can produce excellent clinical results in the frontal, as well as in lateral segments.

SHRUBBY TREE COMPONENT OF RIPARIAN CORRIDORS IN RESTORATION AND NATURAL REMAINING AREAS OF MATRIX FORESTRY, RIO NEGRINHO, SC STATE

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Eliziane Carla Scariot

2014-06-01

Full Text Available http://dx.doi.org/10.5902/1980509814578The aim of this study was to analyze the shrubby tree component in riparian corridors in restoration process and natural remainders in a matrix forestry. We identified the richness, diversity, dispersal and pollination syndromes of the individuals and estimate the floristic similarity. The study was conducted at the producing farm of Pinus spp. wood Santa Alice, located in Rio Negrinho city, Santa Catarina state, Brazil. We adopted the center-quarter method for survey the shrubby tree component in four sample groups: CA (advanced stage of riparian corridors vegetation, CR (riparian corridors in restoration, MA (advanced stage of natural remaining, MI (intermediate stage of natural remaining. We found the highest richness and diversity index in MA and CR. Regarding the number of individuals, the dispersal and pollination syndromes predominant in all sample groups were zoochory and zoophilia. CR and CA had the highest percentage of floristic similarity while MA and MI did not form clusters. The sample group CR has composition, richness and diversity more similar to CA. This indicates that the restoration of riparian zones has conditions to rescue the components and the interactions of an ecological community.

Esthetic rehabilitation of complicated crown fractures utilizing rapid orthodontic extrusion and two different restoration modalities.

Science.gov (United States)

Milardovic Ortolan, Sladana; Strujic, Mihovil; Aurer, Andrej; Viskic, Josko; Bergman, Lana; Mehulic, Ketij

2012-01-01

This case report describes the management of a crown-root fractured maxillary right central incisor and a crown fractured maxillary left central incisor using two different techniques. A complex procedure was designed to manage this case including orthodontic extrusion to move the fracture line above the alveolar bone and surgical recontouring of the altered gingival margin. Finally, the right incisor was restored prosthodontically. Prosthetic treatment was based on performing a post and core, and all-ceramic crown on the extruded tooth. The left, less-damaged incisor was restored directly using composite resin. The treatment resulted in good esthetics and secured periodontal health. This case report demonstrates that a multidisciplinary treatment approach is a reliable and predictable option to save a tooth. How to cite this article: Ortolan SM, Strujic M, Aurer A, Viskic J, Bergman L, Mehulic K. Esthetic Rehabilitation of Complicated Crown Fractures Utilizing Rapid Orthodontic Extrusion and Two Different Restoration Modalities. Int J Clin Pediatr Dent 2012;5(1):64-67.

Tooth anatomy

Science.gov (United States)

... whole tooth. This area is known as the "pulp" of the tooth. The jawbone is attached to ... JC, eds. Robbins and Cotran Pathologic Basis of Disease . 9th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ...

Surgical removal of coronal fragment of tooth embedded in lower lip and esthetic management of fractured crown segment.

Science.gov (United States)

Avinash, Alok; Dubey, Alok; Singh, Rajeev Kumar; Prasad, Swati

2014-01-01

Dental fractures of the permanent maxillary anterior teeth are relatively frequent accidents during childhood. The Efficient diagnosis and treatment of dental injury are important elements in clinical dentistry. This article describes a case of trauma in permanent right central maxillary incisors with tooth fragments embedded in the lower lip. Thorough clinical examination followed by soft tissue radiographs confirmed the presence of a fractured incisal fragment, which was surgically retrieved under local anesthesia. Direct composite restoration was placed. After finishing and polishing, an esthetic and natural-looking restoration was achieved; this completely satisfied the functional and esthetic expectation of the patient and dental team. How to cite this article: Avinash A, Dubey A, Singh RK, Prasad S. Surgical Removal of Coronal Fragment of Tooth Embedded in Lower Lip and Esthetic Management of Fractured Crown Segment. Int J Clin Pediatr Dent 2014;7(1):65-68.

Prevention of dental anomalies in children by prosthetics defects hard tooth tissues and dentitions: the need to possibilities

Directory of Open Access Journals (Sweden)

Suetenkov D.Ye.

2011-03-01

Full Text Available This article presents the possibility of restore the function and anatomy of the tooth and replacement of defects of dentition by prosthesis in children under the removable bite as a method of prevention of dentoalveolar anomalies. Identified the need for prosthetic treatment of children and the willingness of dentists as primary health care professional to address the problems identified. A clinical analysis of complex treatment of defects in the teeth with fixed restorations

Shrinkage stress compensation in composite-restored teeth: relaxation or hygroscopic expansion?

Science.gov (United States)

Meriwether, Laurel A; Blen, Bernard J; Benson, Jarred H; Hatch, Robert H; Tantbirojn, Daranee; Versluis, Antheunis

2013-05-01

Polymerization of composite restorations causes shrinkage, which deforms and thus stresses restored teeth. This shrinkage deformation, however, has been shown to decrease over time. The objective was to investigate whether this reduction was caused by hygroscopic expansion or stress relaxation of the composite/tooth complex. Extracted molars were mounted in rigid stainless steel rings with four spherical reference areas. Twelve molars were prepared with large mesioocclusodistal slots, etched, bonded, and restored with a composite material (Filtek Supreme, 3M ESPE) in two horizontal layers. Ten intact molars were the controls. The teeth were stored either in deionized water or silicone oil. They were scanned after preparation (baseline), restoration (0-week), and after 1, 2, and 4 weeks storage. Scanned tooth surfaces were aligned with the baseline using the unchanged reference areas. Cuspal flexure was calculated from lingual and buccal surface deformation. To verify that the restorations had remained bonded, dye penetration at the interfaces was assessed using basic fuchsin dye. Statistical assessment was done by ANOVA followed by Student-Newman-Keuls post hoc test (p=0.05). Substantial cuspal contraction was found for restored teeth after the composite was cured (13-14 μm cuspal flexure). After 4 weeks cuspal contraction decreased significantly for restored teeth stored in water (7.3 ± 3.2) but not for those stored in silicone oil (11.4 ± 5.0). Dye penetration of the occlusal interface was minimal in both groups (106 ± 87 and 21 ± 28 μm in water and silicone oil, respectively). The results suggest that hygroscopic expansion was the main mechanism for shrinkage stress compensation. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Can dead man tooth do tell tales? Tooth prints in forensic identification.

Science.gov (United States)

Christopher, Vineetha; Murthy, Sarvani; Ashwinirani, S R; Prasad, Kulkarni; Girish, Suragimath; Vinit, Shashikanth Patil

2017-01-01

We know that teeth trouble us a lot when we are alive, but they last longer for thousands of years even after we are dead. Teeth being the strongest and resistant structure are the most significant tool in forensic investigations. Patterns of enamel rod end on the tooth surface are known as tooth prints. This study is aimed to know whether these tooth prints can become a forensic tool in personal identification such as finger prints. A study has been targeted toward the same. In the present in-vivo study, acetate peel technique has been used to obtain the replica of enamel rod end patterns. Tooth prints of upper first premolars were recorded from 80 individuals after acid etching using cellulose acetate strips. Then, digital images of the tooth prints obtained at two different intervals were subjected to biometric conversion using Verifinger standard software development kit version 6.5 software followed by the use of Automated Fingerprint Identification System (AFIS) software for comparison of the tooth prints. Similarly, each individual's finger prints were also recorded and were subjected to the same software. Further, recordings of AFIS scores obtained from images were statistically analyzed using Cronbach's test. We observed that comparing two tooth prints taken from an individual at two intervals exhibited similarity in many cases, with wavy pattern tooth print being the predominant type. However, the same prints showed dissimilarity when compared with other individuals. We also found that most of the individuals with whorl pattern finger print showed wavy pattern tooth print and few loop type fingerprints showed linear pattern of tooth prints. Further more experiments on both tooth prints and finger prints are required in establishing an individual's identity.

Selective saturation method for EPR dosimetry with tooth enamel

International Nuclear Information System (INIS)

Ignatiev, E.A.; Romanyukha, A.A.; Koshta, A.A.; Wieser, A.

1996-01-01

The method of selective saturation is based on the difference in the microwave (mw) power dependence of the background and radiation induced EPR components of the tooth enamel spectrum. The subtraction of the EPR spectrum recorded at low mw power from that recorded at higher mw power provides a considerable reduction of the background component in the spectrum. The resolution of the EPR spectrum could be improved 10-fold, however simultaneously the signal-to-noise ratio was found to be reduced twice. A detailed comparative study of reference samples with known absorbed doses was performed to demonstrate the advantage of the method. The application of the selective saturation method for EPR dosimetry with tooth enamel reduced the lower limit of EPR dosimetry to about 100 mGy. (author)

Optimizing anterior esthetics of a single-tooth implant through socket augmentation and immediate provisionalization: A case report with 7-year follow-up

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Po-Sung Fu

2012-10-01

Full Text Available Tooth extraction inevitably accompanies alveolar ridge resorption with loss of pre-existing tissue morphology. Replacing missing teeth with dental implants has become popular, but restoring anterior teeth with implant-supported restorations is a technique-sensitive task and poses challenges for dentists. With the progress of implant dentistry, the demand for optimal esthetics has become linked with the desire for faster, easier techniques that shorten treatment time and also satisfy patients. Immediate provisionalization of a single-tooth implant provides significant benefits compared with traditional delayed protocols, such as aiding the contouring of peri-implant soft tissue and enhancing patient comfort and satisfaction. This article describes a meticulous approach to a hopeless maxillary central incisor with root fracture. The defect in the extraction socket was reconstructed using autogenous bone harvested from the chin. Four months later, an implant was installed and immediately restored. After another healing period of 6 months, the peri-implant soft tissue had been shaped and matured according to the contours of the provisional restoration. The emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through socket augmentation and immediate provisionalization of the implant. This treatment modality attained predictable and maintainable outcomes, both functionally and esthetically.

Posterior bulk-filled resin composite restorations. A 5-year randomized controlled clinical study

DEFF Research Database (Denmark)

van Dijken, Jan WV; Pallesen, Ulla

2016-01-01

mm as needed to fill the cavity 2 mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2 mm increments. The restorations were evaluated using slightly......, 4 SDR-CeramX mono+ and 6 CeramX mono +-only restorations. The main reasons for failure were tooth fracture (6) and secondary caries (4). The annual failure rate (AFR) for all restorations (Class I and II) was for the bulk-filled-1.1% and for the resin composite-only restorations 1.3% (p = 0...

Immediate provisional restoration of a single-tooth implant in the esthetic zone: A case report

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Po-Sung Fu

2011-02-01

Full Text Available Immediate implant restoration of single implants may demonstrate a positive effect on peri-implant soft tissue. Placement of a provisional restoration following implant surgery can create soft tissue contours that resemble normal gingival topography before placement of the definitive prosthesis. This article describes a staged approach of the mandibular permanent right central incisor, which was congenital missing. The proper space for restoration of the missing incisor was created through orthodontic treatment. The scheduled implant site was reconstructed using autogenous bone harvested from the chin region. After a healing period of four months, an implant was installed with the connection of a fixed provisional crown to a prefabricated temporary abutment. The soft tissue around the implant healed according to the contours of the provisional restoration and the emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through the staged approach and immediate restoration of the implant.

Development of the nervus terminalis in mammals including toothed whales and humans.

Science.gov (United States)

Oelschläger, H A; Buhl, E H; Dann, J F

1987-01-01

The early ontogenesis and topography of the mammalian terminalis system was investigated in 43 microslide series of toothed whale and human embryos and fetuses. In early embryonal stages the development of the nasal pit, the olfacto-terminalis placode, and the olfactory bulb anlage is rather similar in toothed whales and humans. However, toothed whales do not show any trace of the vomeronasalis complex. In early fetal stages the olfactory bulb anlage in toothed whales is reduced and leaves the isolated future terminalis ganglion (ganglia) which contains the greatest number of cells within Mammalia. The ganglion is connected with the nasal mucosa via peripheral fiber bundles and with the telencephalon via central terminalis rootlets. The functional implications of the terminalis system in mammals and its evolution in toothed whales are discussed. Obviously, the autonomic component has been enlarged in the course of perfect adaptation to an aquatic environment.

Marginal Leakage of Class V Composite Resin Restorations

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Maryam Khoroushi

2018-01-01

Full Text Available >Introduction: Marginal leakage is one of the significant causes of restoration failure. This in-vitro study was conducted to compare cone beam computed tomography (CBCT and dye-penetration methods for determining marginal leakage at gingival surface of class V resin composite restorations.Materials and Methods: Class V cavities were prepared on the buccal surfaces of nineteen caries-free extracted human molar teeth. Cavities were conditioned and filled. The teeth were immersed in a 50% w/w aqueous silver nitrate solution for 24 h and were taken out and rinsed with distilled water. Then, they were put into a developing solution. Whole specimens were first viewed with CBCT and were then sectioned and evaluated by stereomicroscope.Results: Measurement of agreement between CBCT and stereomicroscope revealed that 15 (78.9% teeth had score 0, 1 (5.3% tooth had score 1, and 1 (5.3% tooth had score 2 in both techniques. Measurement of agreement between CBCT and stereomicroscope techniques, in the detection of marginal leakage, was 89.5% (Kappa coefficient = 0.627, P = 0.00. The Wilcoxon paired rank test revealed no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin (P = 0.157.Conclusion: Considering the limitations of the study, there was no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin of class V composite restorations. CBCT can be used noninvasively to detect the marginal leakage of gingival wall of class V composite restorations using aqueous silver nitrate solution as a tracer.

Combining structural-thermal coupled field FE analysis and the Taguchi method to evaluate the relative contributions of multi-factors in a premolar adhesive MOD restoration.

Science.gov (United States)

Lin, Chun-Li; Chang, Yen-Hsiang; Lin, Yi-Feng

2008-08-01

The aim of this study was to determine the relative contribution of changes in restorative material, cavity dimensions, adhesive layer adaptation, and load conditions on the biomechanical response of an adhesive Class II MOD restoration during oral temperature changes. A validated finite-element (FE) model was used to perform the structural-thermal coupled field analyses and the Taguchi method was employed to identify the significance of each design factor in controlling the stress. The results indicated that thermal expansion in restorative material amplified the thermal effect and dominated the tooth stress value (69%) at high temperatures. The percentage contributions of the load conditions, cavity depth, and cement modulus increased the effect on tooth stress values 46%, 32%, and 14%, respectively, when the tooth temperature was returned to 37 degrees C. Load conditions were also the main factor influencing the resin cement stress values, irrespective of temperature changes. Increased stress values occurred with composite resin, lateral force, a deeper cavity, and a higher luting cement modulus. The combined use of FE analysis and the Taguchi method efficiently identified that a deeper cavity might increase the risk of a restored tooth fracture, as well as a ceramic inlay with a lower thermal expansion, attaining a proper occlusal adjustment to reduce the lateral occlusal force and low modulus luting material application to obtain a better force-transmission mechanism are recommended.

FACTORS RELATED TO TOOTH LOSS AMONG INDUSTRIAL WORKERS IN PHATHUM THANI, THAILAND.

Science.gov (United States)

Jaaidee, Jeerateep; Chatrchaiwiwatana, Supaporn; Ratanasiri, Amornrat

2017-01-01

Tooth loss is an important oral health problem among Thai people. The objectives of this study were to evaluate the prevalence of and factors associated with tooth loss among Thai industrial workers in order to apply preventive oral health programs to this population. The study consisted of 1,500 adults working in Nava Nakorn Industrial Estate, Pathum Thani Province, Thailand in 2014. Probability proportion to size cluster sampling was used and 16 clusters were included in the study. An oral health questionnaire was developed, evaluated for content validity by experts and then given to participants to fill out. The study population consisted of 621 males (41.4%) and 879 females (58.6%) aged between 19-25 years. The overall prevalence of tooth loss was 62.2% and the major reason for tooth loss was dental caries (60%). Results from multivariable logistic regression analysis show that factors associated with tooth loss were: having a history of scaling or tooth cleaning [adjusted odds ratio (AOR)= 2.47; 95% CI: 1.21-4.65], having dental caries with exposed pulp (AOR=4.12; 95% CI: 3.26-7.67), having tooth mobility due to periodontal disease (AOR=2.41; 95% CI: 2.71-5.22), having needed tooth restoration (AOR=1.75; 95% CI: 1.23-2.65), having a history of maxillofacial or a temporo-mandibular joint accident (AOR=2.13; 95% CI: 1.87- 3.23), wearing dentures (AOR=2.58; 95% CI: 2.17-6.72), using dental care services during the previous year (AOR=2.21; 95% CI: 1.26-4.57), eating snacks and candy daily (AOR=2.14; 95% CI: 1.82-2.92), having toothache (AOR=2.64; 95% CI: 1.43- 3.92), having dental caries (AOR=2.23; 95% CI: 1.62-3.27) and having a history of orthodontic treatment (AOR=3.61; 95% CI: 1.84-5.68). The Nagelkerke R squared for the model was 0.42. Our findings suggest several clinical, socio-economic and lifestyle factors are associated with tooth loss among these Thai industrial workers. An appropriate preventive oral health program targeting this high-risk group taking

Influences of age and maxillary anterior teeth status on patient's satisfaction with dental appearance and tooth colour.

Science.gov (United States)

Lajnert, Vlatka; Pavičić, Daniela K; Gržić, Renata; Kovač, Zoran; Pahor, Dana; Kuis, Davor; Simonić-Kocijan, Sunčana; Antonić, Robert; Bakarčić, Danko

2012-06-01

To study the impact of age, gender, tooth colour and maxillary anterior teeth status on patient's satisfaction with their dental appearance. A total of 259 Caucasian subjects participated in the study (119 men, mean age 56 years; 140 women, mean age 61 years) divided into three age groups (young colour using a scale with three categories: completely dissatisfied, moderately dissatisfied and completely satisfied. Almost half of the participants were completely satisfied with their dental appearance and tooth colour. Half of the 'young' and 'middle-aged' participants with natural maxillary anterior teeth were completely satisfied and half of the 'old' participants were moderately satisfied with their dental appearance and tooth colour. The majority of participants with composite restorations (45-51%) were moderately satisfied with their dental appearance, one-third of 'young' and 'middle-aged' participants were moderately satisfied or dissatisfied with their tooth colour and more than 70% of older participants were dissatisfied with their tooth colour (p > 0.05). Satisfaction with the appearance of the maxillary anterior teeth differed both between individuals of different age and different dental status. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Comparison of proximal contacts of class II resin composite restorations in vitro.

NARCIS (Netherlands)

Loomans, B.A.C.; Opdam, N.J.M.; Roeters, F.J.M.; Bronkhorst, E.M.; Burgersdijk, R.C.W.

2006-01-01

This study investigated the tightness of the proximal contact when placing posterior resin composite restorations with circumferential and sectional matrix systems in an in vitro model using a special measuring device (Tooth Pressure Meter). A manikin model was used with an artificial first molar in

Comparison between published clinical success of direct resin composite restorations in vital posterior teeth in 1995-2005 and 2006-2016 periods.

Science.gov (United States)

Alvanforoush, N; Palamara, J; Wong, R H; Burrow, M F

2017-06-01

Composites are increasing in popularity as restorative materials. This growing role indicates the necessity of studies on their clinical outcome. In this study, clinical studies published on the performance of posterior composite restorations were included except those of less than a 24-month assessment period. Results of non-vital, anterior or primary teeth and cervical single-surface restorations were also excluded. Records about composite type, number of final recall restorations, failure/survival rate, assessment period and failure reasons were analysed for each decade. Overall survival/failure rates for studies in 1995-2005 were 89.41%/10.59% and for 2006-2016 were 86.87%/13.13%, respectively. In 1995-2005, the reasons for failure were secondary caries (29.47%) and composite fracture (28.84%) with low tooth fracture (3.45%) compared with reasons of failure in 2006-2016, which were secondary caries (25.68%), composite fracture (39.07%), and tooth fracture (23.76%). An increase in incidence of composite fracture, tooth fracture and need for endodontic treatment as failure reasons was noted in the latter decade in addition to a decrease in secondary caries, postoperative sensitivity, unsatisfactory marginal adaptation and wear. The overall rates of failure showed little difference, but the causes showed a notable change. This is believed to be a reflection of increased use of composites for larger restorations and possibly changes of material characteristics. © 2016 Australian Dental Association.

Dose response of hydrazine - Deproteinated tooth enamel under blue light stimulation

International Nuclear Information System (INIS)

Yuece, Ulkue Rabia; Meric, Niyazi; Atakol, Orhan; Yasar, Fusun

2010-01-01

The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested.

Dose response of hydrazine - Deproteinated tooth enamel under blue light stimulation

Energy Technology Data Exchange (ETDEWEB)

Yuece, Ulkue Rabia, E-mail: ulkuyuce@hotmail.co [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Meric, Niyazi, E-mail: meric@ankara.edu.t [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Atakol, Orhan, E-mail: atakol@science.ankara.edu.t [Ankara University, Science Faculty, Department of Chemistry, 06100, Tandogan - Ankara (Turkey); Yasar, Fusun, E-mail: ab121310@adalet.gov.t [Council of Forensic Medicine, Ankara Branch, Ankara (Turkey)

2010-08-15

The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested.

In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture.

Science.gov (United States)

Saisadan, D; Manimaran, P; Meenapriya, P K

2016-10-01

Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties - flexural strength, compressive strength, and color stability. The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan). It was inferred from the study that no one material was superior in all three tested parameters.

Oral environment control before restorative treatment

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Ian Matos Vieira

2008-01-01

Full Text Available The aim of the present study was to describe caries disease treatment, by means of a clinical case report, with a view to promoting the patient’s health before definitive restorative treatments, considering that treatment should include changes in the patient’s dietary and hygiene habits, and not be restricted only to restoring lesions, as well as the establishment of an individualized treatment plan for each patient. Iodine-based antimicrobial solution was applied, instructions about oral hygiene and dietary habit changes were provided. The stepwise excavation technique was performed in tooth 15, mass excavation followed by the application of glass ionomer cement in the other teeth that presented carious lesions. White stain lesions were remineralized, and cicatrizes and fissures in the posterior teeth were sealed. After health was reestablished, the temporary restorations were replaced by definitive restorations. Changes in the treatment philosophy of caries disease, based on changes in the patient’s habits and removal of foci of infection have been presented with the object of producing an effective change in this paradigm, in order to increase the longevity of teeth with less operative intervention.

Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

International Nuclear Information System (INIS)

Musa, Marahaini; Ponnuraj, Kannan Thirumulu; Mohamad, Dasmawati; Rahman, Ismail Ab

2013-01-01

Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions. (paper)

Risk factors for developing tooth sensitivity and gingival irritation associated with nightguard vital bleaching.

Science.gov (United States)

Leonard, R H; Haywood, V B; Phillips, C

1997-08-01

The purpose of this study was to determine risk factors in the development of tooth sensitivity and gingival irritation associated with the nightguard vital bleaching technique. The potential risk factors evaluated (sex, age, reported allergy, whitening solution, number of times the solution was changed daily [its usage pattern], and dental arch) were collected from the daily log form turned in by each of the 64 participants after completion of the 6-week lightening process. Also evaluated for each participant, from color slides, were tooth characteristics such as gingival recession, defective restorations, abfraction lesions, enamel-cementum abrasion, etc, and reported side effects. The generalized Mantel-Haenszel statistic was used to assess the association between the potential risk factors and the development of tooth sensitivity and/or gingival irritation. No statistical relationship existed between age, sex, allergy, tooth characteristics, or the dental arch lightened and the development of side effects. Initially, a statistically significant association existed between side effects and the whitening solution used. However, when the analysis was controlled for usage pattern, this relationship disappeared. Patients who changed the whitening solution more than once a day reported statistically significantly more side effects than did those who did not change the whitening solution during their usage time.

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Behjat-Al-Molook Ajami

2013-01-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Taraneh Movahhed

2012-09-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration.

Lateral-access Class II restoration using resin-modified glass-ionomer or silver-cermet cement.

Science.gov (United States)

Croll, T P

1995-02-01

Direct-access preparation of a carious proximal surface is perhaps the most conservative approach to restoration. Physical properties and handling characteristics of silver amalgam and of resin composite and lack of fluoride ion release make these materials unsuitable for direct buccal- or lingual-access proximal restoration. Insufficient strengths and radiolucency of self-hardening glass-ionomer cements preclude their use for Class II restorations. However, glass-ionomer silver-cermet cement and some resin-modified glass-ionomer materials are proving useful for non-stress-bearing Class II restorations and may have applications in preventive dentistry. This article describes lateral-access Class II restoration with modified glass-ionomer cements. Emphasis is placed on careful handling of materials, maintenance of an ideal operative field, and conservation of tooth structure.

Mathematical description of tooth flank surface of globoidal worm gear with straight axial tooth profile

Science.gov (United States)

Połowniak, Piotr; Sobolak, Mariusz

2017-12-01

In this article, a mathematical description of tooth flank surface of the globoidal worm and worm wheel generated by the hourglass worm hob with straight tooth axial profile is presented. The kinematic system of globoidal worm gear is shown. The equation of globoid helix and tooth axial profile of worm is derived to determine worm tooth surface. Based on the equation of meshing the contact lines are obtained. The mathematical description of globoidal worm wheel tooth flank is performed on the basis of contact lines and generating the tooth side by the extreme cutting edge of worm hob. The presented mathematical model of tooth flank of TA worm and worm wheel can be used e.g. to analyse the contact pattern of the gear.

Recent advances in engineering of tooth and tooth structures using postnatal dental cells

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Masaki J. Honda

2010-02-01

This review focuses on the performance of postnatal and adult dental cells that have been used for generating teeth. Their ability to contribute to tooth development was assessed in the omentum or in the tooth socket. Adult dental cells were limited in their potential owing to various parameters. From these results described, new approaches for regenerated teeth are proposed in this review. One strategy to replace teeth is tooth root engineering using tissue from postnatal teeth. Since the enamel organ epithelium disappears after tooth maturation, the epithelial rest cells of Malassez were evaluated to determine their capacity to generate enamel. From these results, it is suggested that erupted mature teeth have cell sources with the capacity to produce tooth root. The development of biological approaches for tooth root regeneration using postnatal dental cells is promising and remains one of the greatest challenges in the dental field in the years to come.

Revascularization procedure in an open apex tooth with external root resorption: A case report

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Mahsa Dastpak

2017-06-01

Full Text Available External inflammatory root resorption (EIR represents a challenge in endodontic practice. EIR commonly occurs after dental trauma that results in periodontal ligament injury, pulp necrosis and subsequent infection.  Treatment of EIR is based on disinfecting the root canal system through chemomechanical procedures and then filling it with calcium hydroxide or triple antibiotic paste. Dental trauma commonly occurs in young patients whose teeth are not fully formed and have thin dentinal walls and open apices. Revascularization therapy has proven to be suitable for treatment of root canals of teeth with pulp necrosis and open apices. This case report presents successful revascularization treatment of a permanent immature tooth with external root resorption and chronic apical periodontitis. The tooth was treated by the protocol suggested by the American Association of Endodontics (AAE, consisted of disinfecting the root canal system, filling it with blood clot and sealing the root canal with mineral trioxide aggregate followed by bonded resin restoration. The symptoms disappeared, the size of the periapical lesion reduced and the tooth was asymptomatic during the 12 month follow up period.

Multivariate image analysis of laser-induced photothermal imaging used for detection of caries tooth

Science.gov (United States)

El-Sherif, Ashraf F.; Abdel Aziz, Wessam M.; El-Sharkawy, Yasser H.

2010-08-01

Time-resolved photothermal imaging has been investigated to characterize tooth for the purpose of discriminating between normal and caries areas of the hard tissue using thermal camera. Ultrasonic thermoelastic waves were generated in hard tissue by the absorption of fiber-coupled Q-switched Nd:YAG laser pulses operating at 1064 nm in conjunction with a laser-induced photothermal technique used to detect the thermal radiation waves for diagnosis of human tooth. The concepts behind the use of photo-thermal techniques for off-line detection of caries tooth features were presented by our group in earlier work. This paper illustrates the application of multivariate image analysis (MIA) techniques to detect the presence of caries tooth. MIA is used to rapidly detect the presence and quantity of common caries tooth features as they scanned by the high resolution color (RGB) thermal cameras. Multivariate principal component analysis is used to decompose the acquired three-channel tooth images into a two dimensional principal components (PC) space. Masking score point clusters in the score space and highlighting corresponding pixels in the image space of the two dominant PCs enables isolation of caries defect pixels based on contrast and color information. The technique provides a qualitative result that can be used for early stage caries tooth detection. The proposed technique can potentially be used on-line or real-time resolved to prescreen the existence of caries through vision based systems like real-time thermal camera. Experimental results on the large number of extracted teeth as well as one of the thermal image panoramas of the human teeth voltanteer are investigated and presented.

Tooth - abnormal colors

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... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

Spectrophotometric assessment of tooth bleaching under orthodontic braquets bonded with different materials

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Camila Maria Lima de CASTRO

2017-10-01

Full Text Available Abstract Introduction patients have been submitted to tooth bleaching during orthodontic treatment for aesthetic purposes or to anticipate the replacement of restorations after completion of the treatment. Objective to evaluate the effectiveness of tooth bleaching under orthodontic brackets bonded with different materials. Material and method a hundred bovine enamel blocks were divided into two groups, at-home and in-office tooth bleaching. In-office bleaching was subdivided into five groups (n = 10: HP (control - without brackets; SA(t - brackets bonded with Transbond XT, without bleaching; SA(fm - brackets bonded with Orthodontic Fill Magic, without bleaching; HP(t - brackets bonded with Transbond XT subjected to bleaching; and HP(fm - brackets bonded with Orthodontic Fill Magic subjected to bleaching. At-home bleaching followed the same treatments, only replacing the bleaching agent. Spectrophotometric assessment was used for tooth color determination at three moments: 1 before staining (baseline; 2 after staining; 3 after bonding the brackets and bleaching procedures. Data were submitted to ANOVA and analyzed by Tukey's test (p < 0.05. Result For both types of bleaching, the control group had an effective bleaching action. Groups using Transbond XT presented greater bleaching potential among the groups with orthodontic accessory, but the bleaching action differed from the positive control. Groups using Orthodontic Fill Magic presented no bleaching action, resembling the negative control groups (artificial saliva. Conclusion the orthodontic bracket impaired the effectiveness of the at-home and in-office bleaching treatment, regardless of the resin used for bonding.

Restorative outcomes for endodontically treated teeth in the Practitioners Engaged in Applied Research and Learning network.

Science.gov (United States)

Spielman, Howard; Schaffer, Scott B; Cohen, Mitchell G; Wu, Hongyu; Vena, Donald A; Collie, Damon; Curro, Frederick A; Thompson, Van P; Craig, Ronald G

2012-07-01

The authors aimed to determine the outcome of and factors associated with success and failure of restorations in endodontically treated teeth in patients in practices participating in the Practitioners Engaged in Applied Research and Learning (PEARL) Network. Practitioner-investigators (P-Is) invited the enrollment of all patients seeking care at participating practices who had undergone primary endodontic therapy and restoration in a permanent tooth three to five years earlier. P-Is classified endodontically reated teeth as restorative failures if the restoration was replaced, the restoration needed replacement or the tooth was cracked or fractured. P-Is from 64 practices enrolled in the study 1,298 eligible patients who had endodontically treated teeth that had been restored. The mean (standard deviation) time to follow-up was 3.9 (0.6) years. Of the 1,298 enrolled teeth, P-Is classified 181 (13.9 percent; 95 percent confidence interval [CI], 12.1-15.8 percent) as restorative failures: 44 (3.4 percent) due to cracks or fractures, 57 (4.4 percent) due to replacement of the original restoration for reasons other than fracture and 80 (6.2 percent) due to need for a new restoration. When analyzing the results by means of multivariate logistic regression, the authors found a greater risk of restorative failure to be associated with canines or incisors and premolars (P = .04), intracoronal restorations (P < .01), lack of preoperative proximal contacts (P < .01), presence of periodontal connective-tissue attachment loss (P < .01), younger age (P = .01), Hispanic/Latino ethnicity (P = .04) and endodontic therapy not having been performed by a specialist (P = .04). These results suggest that molars (as opposed to other types of teeth), full-coverage restorations, preoperative proximal contacts, good periodontal health, non-Hispanic/Latino ethnicity, endodontic therapy performed by a specialist and older patient age are associated with restorative success for

SEM Evaluation of Internal Adaptation of Bases and Liners under Composite Restorations

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Dimitrios Dionysopoulos

2014-04-01

Full Text Available The aim of this study was to evaluate the interfacial microgaps generating between different materials and between materials and dentin after polymerization of the composite restorations, using SEM. Methods: The materials investigated were a composite, an adhesive, a RMGI, and a calcium hydroxide. Thirty third molars were selected and two circular class V cavities (5 mm × 3 mm for each tooth were made. The teeth were randomly assigned into six groups and restored with a combination of the materials. The specimens were subjected to thermocycling and each tooth was sectioned mesiodistally in two halves. Each half was sectioned along the longitudinal axis through the center of the restorations to obtain a slice of 2 mm. The specimens were examined under SEM. The interfaces between the liners, the liners and dentin, and between the liners and the composite were examined for microgaps. Results: The results showed that there was not any significant difference in the mean width of microgaps in the interfaces between Dycal-dentin and Vitrebond-dentin (p>0.05. However, the width of microgaps in the interfaces between dentin-Clearfil Tri-S Bond was significantly smaller (p<0.05. The use of Clearfil Tri-S Bond reduced the possibility of microgap formation between the bonded interface and the materials tested.

Fracture resistance of teeth restored with packable and hybrid composites

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Ghavam M

2006-06-01

Full Text Available Background and Aim: With recent introduction of packable composites, it is claimed that they apply less stress on tooth structure because of reduced polymerization shrinkage, and similarity of coefficient of thermal expansion to tooth structure. However, the high viscosity may in turn cause less adaptation, so it is not clearly known whether these materials strengthen tooth structure or not. The aim of this study was to evaluate fracture resistance of maxillary premolars, receiving hybrid or packable composite restorations with different methods of application and curing. Materials and Methods: In this experimental study, seventy five intact premolars were randomly assigned to five groups of 15 teeth each. One group was maintained intact as the control group. Similar MOD cavities were prepared in the other teeth. The teeth in group two were restored with Spectrum in incremental layers and light cured with 500 mw/cm2 intensity. The third group were filled with Surefil and cured with light intensity of 500 mw/cm2. The groups four and five were restored with Surefil in bulk technique with two different modes: 500 mw/cm2 intensity and a ramp mode (100-900 mw/cm2 respectively. After thermocycling, force to fracture was assessed and degree of conversion (DC at the bottom of cavities was evaluated for different modes and methods. The curing and placement methods in groups tested for DC (A to D were the same as fracture resistance groups (2 to 5. Data were analyzed using one way ANOVA and Tukey HSD tests with p<0.05 as the limit of significance. Results: All the restored groups showed significantly less fracture resistance than the control group, but had no significant difference among themselves. DC of Spectrum was higher than Surefil. Bulk method with 500 mw/cm2 light intensity, significantly decreased DC. DC in bulk method with high light intensity was not significantly different from incremental method with 500 mw/cm2 light intensity. Conclusion

Clinical considerations in restorative dentistry - A narrative review

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Ashwini Tumkur Shivakumar

2015-01-01

Full Text Available The relationship between periodontal health and the restoration of teeth is intimate and inseparable. Human teeth are designed in such a way that the individual tooth contributes significantly to their own support as well as collectively the teeth in the arch. Decay on the proximal surfaces occurs mainly due to the faulty interrelationship between the contact area, marginal ridge, the embrasures and the gingiva. An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure an adequate form, function, aesthetics and comfort of the dentition. For long-term survival of restoration, both functionally and esthetically, certain biological considerations are very critical to preserve the health of the periodontium and thus must be given due importance in clinical practice. While most clinicians are aware of this important relationship, uncertainly remains regarding specific concept such as biologic width and its maintainces.

The restoration of a maxillary central incisor fracture with the original crown fragment using a glass fiber-reinforced post: a clinical report.

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Durkan, Rukiye Kaplan; Ozel, M Birol; Celik, Davut; Bağiş, Bora

2008-12-01

This report describes an esthetic, conservative, and economical alternative restoration technique for a fractured central incisor using the patient's own tooth crown piece and a bondable reinforcement glass fiber. Although the long-term durability of this adhesive post core restoration remains unknown, it remains successful after 1 year.

Remakes of Colorlogic and IPS Empress ceramic restorations in general practice.

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Hekland, Helge; Riise, Trond; Berg, Einar

2003-01-01

The aim of this article was to study frequencies and distribution of remakes of all-ceramic inlays/onlays, veneers, and crowns occurring before and after cementation. A total of 2,069 sintered feldspathic ceramic restorations (Colorlogic) and 1,136 pressure-molded ceramic restorations (IPS Empress 1 and 2) were produced during the study period by one dental laboratory. The laboratory gave an unqualified and unlimited guarantee for their ceramic restorations. The outcome variable was reports from the clinicians to the dental laboratory about any problems related to the restoration, necessitating remake. Problems occurring before cementation occurred in 4.4% of the restorations. Veneers were remade more frequently than the other types of restorations (6.6%). After cementation, the overall 2-year rate of remakes was 1%, indicating a survival rate of the ceramic restorations of 99%, with inlays/onlays exhibiting the highest (99.8%) and crowns the lowest (98.4%) rates. This difference in rates was significant. No significant differences in remakes between ceramics or tooth categories were found. There were few problems in a short- to medium-term perspective that, in the opinion of general practitioners, necessitated remakes of all-ceramic restorations.

In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture

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D Saisadan

2016-01-01

Full Text Available Introduction: Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. Acrylics: These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. Composites: Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. Preformed Crowns: Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. Aims and Objectives: The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties – flexural strength, compressive strength, and color stability. Materials and Methods: The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan. Result: It was inferred from the study that no one material was superior in all three tested parameters.

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

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Pektaş, Ömer; Tönük, Ergin

2014-11-01

At the interface between the jawbone and the roots of natural teeth, a thin, elastic, shock-absorbing tissue, called the periodontal ligament, forms a cushion which provides certain flexibility under mechanical loading. The dental restorations supported by implants, however, involve comparatively rigid connections to the jawbone. This causes overloading of the implant while bearing functional loading together with neighboring natural teeth, which leads to high stresses within the implant system and in the jawbone. A dental implant, with resilient components in the upper structure (abutment) in order to mimic the mechanical behavior of the periodontal ligament in the axial direction, was designed, analyzed in silico, and produced for mechanical testing. The aims of the design were avoiding high levels of stress, loosening of the abutment connection screw, and soft tissue irritations. The finite element analysis of the designed implant revealed that the elastic abutment yielded a similar axial mobility with the natural tooth while keeping stress in the implant at safe levels. The in vitro mechanical testing of the prototype resulted in similar axial mobility predicted by the analysis and as that of a typical natural tooth. The abutment screw did not loosen under repeated loading and there was no static or fatigue failure. © IMechE 2014.

Dentist and practice characteristics associated with restorative treatment of enamel caries in permanent teeth

DEFF Research Database (Denmark)

Fellows, Jeffrey L; Gordan, Valeria V; Gilbert, Gregg H

2014-01-01

PURPOSE: Current evidence in dentistry recommends non-surgical treatment to manage enamel caries lesions. However, surveyed practitioners report they would restore enamel lesions that are confined to the enamel. Actual clinical data were used to evaluate patient, dentist, and practice...... characteristics associated with restoration of enamel caries, while accounting for other factors. METHODS: Data from a National Dental Practice-Based Research Network observational study of consecutive restorations placed in previously unrestored permanent tooth surfaces and practice/demographic data from 229...... participating network dentists were combined. ANOVA and logistic regression, using generalized estimating equations (GEE) and variable selection within blocks, were used to test the hypothesis that patient, dentist, and practice characteristics were associated with variations in enamel restorations of occlusal...

Effect of prophylactic polishing protocols on the surface roughness of esthetic restorative materials.

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Neme, A L; Frazier, K B; Roeder, L B; Debner, T L

2002-01-01

Many polishing protocols have been evaluated in vitro for their effect on the surface roughness of restorative materials. These results have been useful in establishing protocols for in vivo application. However, limited research has focused on the subsequent care and maintenance of esthetic restorations following their placement. This investigation evaluated the effect of five polishing protocols that could be implemented at recall on the surface roughness of five direct esthetic restorative materials. Specimens (n=25) measuring 8 mm diameter x 3 mm thick were fabricated in an acrylic mold using five light-cured resin-based materials (hybrid composite, microfilled composite, packable composite, compomer and resin-modified glass ionomer). After photopolymerization, all specimens were polished with Sof-Lex Disks to produce an initial (baseline) surface finish. All specimens were then polished with one of five prophylactic protocols (Butler medium paste, Butler coarse paste, OneGloss, SuperBuff or OneGloss & SuperBuff). The average surface roughness of each treated specimen was determined from three measurements with a profilometer (Surface 1). Next, all specimens were brushed 60,000 times at 1.5 Hz using a brush-head force of 2 N on a Manly V-8 cross-brushing machine in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness of each specimen was measured after brushing (Surface 2) followed by re-polishing with one of five protocols, then final surface roughness values were determined (Surface 3). The data were analyzed using repeated measures ANOVA. Significant differences (p=0.05) in surface roughness were observed among restorative materials and polishing protocols. The microfilled and hybrid resin composite yielded significantly rougher surfaces than the other three materials following tooth brushing. Prophylactic polishing protocols can be used to restore a smooth surface on resin-based esthetic restorative materials following simulated tooth

[Experimental analysis of finishing lines in ceramometal restorations].

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Gascón, F; Gil, J A; Fons, A; Badal, R

1990-11-01

The preparation is the first step of any tooth reconstruction. The biological integration of the protesis is depending on the marginal adaptation (finish line of the preparation), occlusal adaptation (occlusal reduction), longevity of the restoration (retention and luting) and esthetics. The effect the two finish line of the preparation is studied using experimental design. In porcelain-fused-to-metal the finish line of the preparation in chanfer is superior at the beveled shoulder, because proportioning better marginal adaptation.

Effect of rotary cutting instruments on the resin-tooth interfacial ultra structure: An in vivo study.

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Sherawat, Sudhir; Tewari, Sanjay; Duhan, Jigyasa; Gupta, Alpa; Singla, Rakesh

2014-12-01

To evaluate the effect of cutting teeth with different types of burs at various speeds on surface topography of tooth surface and interfacial gap formation at resin-tooth interface. The human molars were divided into seven groups: Diamond bur in airrotor (DA) & micromotor (DM), crosscut carbide bur in airrotor (CCA) & micromotor (CCM), plain carbide bur in airrotor (CA) & micromotor (CM) and #600-grit silicon carbide paper (SiC). In five samples from each group Class II box-only cavities were restored. The occlusal surface of four teeth per group was flattened. Two out of four teeth were acid etched. Teeth were subjected for scanning electron microscopy (SEM). Interfacial gap was observed in all groups with no significant difference. SEM observations revealed CA, CCA & DA were coarser than CM, CCM, DM and SiC. SEM of etched tooth surfaces revealed complete removal of amorphous smear layer in CA & CM, partial removal in CCA, CCM, DA & DM and no removal in SiC. Selecting an appropriate bur and its speed may not play an important role in bonding in terms of interfacial gap formation. Variable changes were observed in surface topography with different burs before and after acid etching. Key words:Surface topography, resin-tooth interface, interfacial gap, bonding.

Orthodontic Tooth Movement: A Historic Prospective.

Science.gov (United States)

Will, Leslie A

2016-01-01

The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement. In this theory, fluid from the vasculature, lymphatic system and intercellular spaces responds to the forces of tooth movement, damping the force and limiting movement. Bien and Baumrind expanded on this theory with their own studies in the 1960s. It is clear that both the pressure-tension and fluid flow concepts have merit, but considerable work needs to be done to ascertain the details so that tooth movement can be managed and controlled. © 2016 S. Karger AG, Basel.

Effect of Enamel and Dentin Irradiation by Gamma Rays on the Bond Strength of Two Adhesive Restorations

International Nuclear Information System (INIS)

Zein, N.S.A.

2014-01-01

There have been many reports related to the high incidence of the head and neck cancers including those of the oral cavity. Ablative surgery, radiotherapy, chemotherapy and reconstructive surgery are components of the curative or palliative treatment of head and neck cancers which are intended to improve survival time and quality of life. In addition to the desirable anticancer effects, ionizing radiation causes damage to normal tissues located within the irradiation fields (1). The early responses of teeth to irradiation include dental hypersensitivity and spontaneous pain (2). Several types of desensitizers may be applied to the tooth after cavity preparation in an attempt to manage dental hypersensitivity. The most common form of management is the placement of a topically applied agent either by a dental professional or by the patient at home. These agents stimulate mineral deposition or occlude dental tubules to reduce hypersensitivity (3,4). Radiation caries is another irradiation-related damage to dental structures. It remains the most threatening complication of radiotherapy for the dentition. It is a highly destructive form of dental caries with a rapid onset and progression. Radiation caries may become evident as early as three months following the initiation of head and neck radiotherapy. In severe cases, a previously healthy dentition can be completely lost within a year (5). Radiation caries involves both enamel and dentin; it tends to first affect the cervical and incisal edges of the teeth. Beside the irradiation-induced xerostomia, the effect of irradiation on dental hard tissues may be an important factor in radiation caries. Studies have reported the physical and chemical changes in enamel after radiotherapy, which are a direct consequence of the irradiation treatment. For dentin, a significant reduction in microhardness is observed after irradiation accompanied by reduced stability of the dentino-enamel junction (DEJ) The oral environment of head

Evaluation of fracture resistance of endodontically treated teeth restored with prefabricated posts and composites with varying quantities of remaining coronal tooth structure Avaliação da resistência à fratura de dentes tratados endodonticamente restaurados com pinos pré-fabricados e resinas compostas variando o remanescente dentário coronal

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Murilo Pereira de Melo

2005-06-01

Full Text Available OBJECTIVES: The aim of this study was to evaluate the influence of remaining coronal tooth structure on endodontically treated teeth restored with prefabricated posts and two different composites for core build-up: dual-cured resin (Enforce Core and light-cured resin (Z-250. METHODS: Fourty freshly extracted canines were endodontically treated and divided into four groups: Group I - teeth with 3mm remaining coronal structure, restored with Enforce Core; Group II - teeth with 3mm remaining coronal structure, restored with Z-250; Group III - teeth with no remaining coronal structure, restored with Enforce; Group IV - teeth with no remaining coronal structure, restored with Z-250. After restoration, the teeth were embedded in acrylic resin and the fracture resistance was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. RESULTS: Data were analyzed by two-way analysis of variance, which showed significant differences between groups (p=0.00. The Tukey test did not show significant differences between specimens with and without remaining coronal structure. Conversely, significant difference was observed between groups with different core build-up. The highest values of fracture resistance were found in the group restored with light-cured resin. SIGNIFICANCE: The remaining coronal tooth structure did not influence the resistance of endodontically treated teeth; however, the change of core build-up was able to modify this resistence.O objetivo desta pesquisa foi avaliar a influência do remanescente dentário coronal de dentes tratados endodonticamente, restaurados com pinos pré-fabricados e duas resinas como núcleos de preenchimento, uma de presa dual (Enforce Core e outra fotopolimerizável (Z-250. Foram utilizados 40 caninos superiores humanos extraídos, divididos em quatro grupos de 10 espécimes: Grupo l - com remanescente dentário coronal de 3mm e restaurados com Enforce Core; Grupo ll - com

Effects of oral hygiene, residual caries and cervical Marginal-gaps on the survival of proximal atraumatic restorative treatment approach restorations

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Arthur M Kemoli

2011-01-01

Full Text Available Background: Although Atraumatic restorative treatment (ART approach has been in existence for a while, the reasons for the poor performance of multisurface ART restorations are not very clear. Aim: The aim of this study is to investigate the effects of oral hygiene, residual caries and cervical marginal-gaps on survival of proximal ART restorations. Settings: Two rural divisions in Kenya were selected for the study. Design: A randomized clinical trial. Material and Methods: The 804 children in the study had their baseline- and 2-year dental plaque levels documented. Each child received one proximal restoration in a primary molar using ART approach, together with trained and pre-tested operators/assistants, three glass ionomer cements (GIC-brands and two tooth-isolation methods. The restorations were clinically evaluated soon after placement and after 2 years. Post-restorative bite-wing radiographs taken soon after restoration were also evaluated. Statistical analysis: Statistical Package for Social Sciences (SPSS version 14 computer programme was used and results tested using Pearson′s correlation, Cox Proportional Hazards regression analysis and Multiple Logistic regression models tests. Results: At baseline and after 2 years, the mean cumulative survival and plaque index changed from 94.4% to 30.8% and 2.34 (Standard Deviation, or SD of 0.46 to 1.92 (SD 2.1 respectively, with higher plaque indices associated with higher restoration failures. Of the 507 radiographs evaluated, 48 (9.5%, 63 (12.4% and 9 (1.8% restorations had residual caries (RC, cervical marginal-gaps (CMG and both RC/CMG respectively. Survival of the restorations with RC/CMG was significantly lower (p = 0.003 compared to those with RC or without RC. Conclusion: Low survival of proximal restorations in the study was associated with the presence of cervical marginal-gaps.

Mechanism of Calcite Co-Orientation in the Sea Urchin Tooth

Energy Technology Data Exchange (ETDEWEB)

Killian, Christopher; Metzler, Rebecca; Gong, Y. U. T.; Olson, Ian; Aizenberg, Joanna; Politi, Yael; Wilt, Fred; Scholl, Andreas; Young, Anthony; Doran, Andrew; Kunz, Martin; Tamura, Nobumichi; Coppersmith, Susan; Gilbert, P. U. P. A.

2009-12-01

Sea urchin teeth are remarkable and complex calcite structures, continuously growing at the forming end and self-sharpening at the mature grinding tip. The calcite (CaCO{sub 3}) crystals of tooth components, plates, fibers, and a high-Mg polycrystalline matrix, have highly co-oriented crystallographic axes. This ability to co-orient calcite in a mineralized structure is shared by all echinoderms. However, the physico-chemical mechanism by which calcite crystals become co-oriented in echinoderms remains enigmatic. Here, we show differences in calcite c-axis orientations in the tooth of the purple sea urchin (Strongylocentrotus purpuratus), using high-resolution X-ray photoelectron emission spectromicroscopy (X-PEEM) and microbeam X-ray diffraction ({mu}XRD). All plates share one crystal orientation, propagated through pillar bridges, while fibers and polycrystalline matrix share another orientation. Furthermore, in the forming end of the tooth, we observe that CaCO{sub 3} is present as amorphous calcium carbonate (ACC). We demonstrate that co-orientation of the nanoparticles in the polycrystalline matrix occurs via solid-state secondary nucleation, propagating out from the previously formed fibers and plates, into the amorphous precursor nanoparticles. Because amorphous precursors were observed in diverse biominerals, solid-state secondary nucleation is likely to be a general mechanism for the co-orientation of biomineral components in organisms from different phyla.

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

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Sang-Mi Yun

2012-02-01

Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Matching the optical properties of direct esthetic dental restorative materials to those of human enamel and dentin

Science.gov (United States)

Ragain, James Carlton, Jr.

One of the goals of the restorative dentist is to restore the appearance of the natural dentition. Clinical matching of teeth and restorative materials are seldom accurate and shade selection techniques are subjective. The first specific aim of this research was to characterize the optical absorption and scattering that occurs within enamel, dentin, and composite resin and compomer restorative materials and to relate those phenomena to translucency and color. The second aim was to evaluate small color differences among composite restorative materials which would be detectable by humans. The last aim was to lay the foundation for developing an improved model of specifying layers of dental restorative materials in order to match the translucency and color to those of human enamel. The Kubelka-Munk theory was validated for enamel, dentin, and the restorative materials. These tissues and materials were then characterized in terms of their color parameters. Tooth cores were also characterized in terms of color space parameters. Human subjects were evaluated for their abilities to discriminate small color differences in the dental composite resin materials. The following conclusions were derived from this study: (1) Kubelka-Munk theory accurately predicts the diffuse reflectance spectra of enamel, dentin, and the direct esthetic dental restorative materials studied. (2) Scattering and absorption coefficients of the dental tissues and esthetic restorative materials can be directly calculated from diffuse reflectance measurements of a uniformly thick slab of tissue/material using black and white backings and the appropriate refractive index. (3) For tooth cores, there is a positive correlation between L* and b* and a negative correlation between L* and a*. (4) The range of translucency parameters for the restorative materials studied does not match those of enamel and dentin. (5) None of the shades of the dental composite resin restorative materials studied fit into the

[Assessment of tooth bleaching efficacy with spectrophotometer].

Science.gov (United States)

Zhu, Wenhao; Liu, Chang; Pan, Jie

2014-06-01

To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

Interim restorations.

Science.gov (United States)

Gratton, David G; Aquilino, Steven A

2004-04-01

Interim restorations are a critical component of fixed prosthodontic treatment, biologically and biomechanically. Interim restoration serves an important diagnostic role as a functional and esthetic try-in and as a blueprint for the design of the definitive prosthesis. When selecting materials for any interim restoration, clinicians must consider physical properties, handling properties, patient acceptance, and material cost. Although no single material meets all the requirements and material classification alone of a given product is not a predictor of clinical performance, bis-acryl materials are typically best suited to single-unit restorations, and poly(methylmethacrylate) interim materials are generally ideal for multi-unit, complex, long-term, interim fixed prostheses. As with most dental procedures, the technique used for fabrication has a greater effect on the final result than the specific material chosen.

Overview of Tooth Disorders

Science.gov (United States)

... teeth using a thin resin cement. Bleaching, or tooth whitening, is a process used by dentists to lighten ... following? Damage to only the hard outer surface (enamel) of the tooth An incomplete fracture of a ...

Dental radiography: tooth enamel EPR dose assessment from Rando phantom measurements

International Nuclear Information System (INIS)

Aragno, D.; Fattibene, P.; Onori, S.

2000-01-01

Electron paramagnetic resonance dosimetry of tooth enamel is now established as a suitable method for individual dose reconstruction following radiation accidents. The accuracy of the method is limited by some confounding factors, among which is the dose received due to medical x-ray irradiation. In the present paper the EPR response of tooth enamel to endoral examination was experimentally evaluated using an anthropomorphic phantom. The dose to enamel for a single exposure of a typical dental examination performed with a new x-ray generation unit working at 65 kVp gave rise to a CO 2 -signal of intensity similar to that induced by a dose of about 2 mGy of 60 Co. EPR measurements were performed on the entire tooth with no attempt to separate buccal and lingual components. Also the dose to enamel for an orthopantomography exam was estimated. It was derived from TLD measurements as equivalent to 0.2 mGy of 60 Co. In view of application to risk assessment analysis, in the present work the value for the ratio of the reference dose at the phantom surface measured with TLD to the dose at the tooth measured with EPR was determined. (author)

Influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage restorations.

Science.gov (United States)

Bakeman, E M; Rego, N; Chaiyabutr, Y; Kois, J C

2015-01-01

This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (pceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (pceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

Dental Caries (Tooth Decay)

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... Materials Contact Us Home Research Data & Statistics Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Dental Caries (Tooth Decay)

Science.gov (United States)

... Contact Us Home Research Data & Statistics Share Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Fifteen-year Clinical Follow-up of Restoration of Extensive Cervical Resorption in a Maxillary Central Incisor.

Science.gov (United States)

Reston, E G; Bueno, Rpr; Closs, L Q; Zettermann, J

Internal bleaching in endodontically treated teeth requires care and protection to prevent harm to the periodontal ligament due to peroxide and may result in external root resorption. There is a myriad of treatment options when this occurs, such as monitoring, extraction, and subsequent rehabilitation with implants or fixed prosthodontics. In some cases, such as the one described here, a conservative attempt to maintain the tooth as a single structure can be made by sealing the resorptive defect. In the present case, we show a multidisciplinary approach where orthodontics, periodontics, and restorative dentistry were involved in treating the maxillary right central incisor (#8) of a 65-year-old patient with extensive cervical resorption, whose chief complaint was esthetics. The proposed treatment was extrusion of the tooth followed by curettage and restoration of the defect with glass ionomer cement. The patient has been followed for 15 years with no signs of recurrence, maintenance of periodontal health, and patient satisfaction with the esthetic outcome.

A randomized controlled 27 years follow up of three resin composites in Class II restorations

DEFF Research Database (Denmark)

Pallesen, Ulla; van Dijken, Jan WV

2015-01-01

.1%), followed by occlusal wear (21.6%) and material fracture (18.9%). Non-acceptable color match was seen in 24 (28.3%) of the restorations (AII 2, CP 16, O 6). Cox regression-analysis showed significant influence of the covariates tooth type, caries risk, and bruxing activity of the participants. Conclusions...

Immunohistochemistry of the intercellular matrix components and the epithelio-mesenchymal junction of the human tooth germ

DEFF Research Database (Denmark)

Matthiessen, M E; Olsen, B E; Moe, D

1994-01-01

The immunohistochemical localization of heparan sulphate, collagen type I, III and IV, laminin, tenascin, plasma- and cellular fibronectin was studied in tooth germs from human fetuses. The lamina basalis ameloblastica or membrana preformativa, which separates the pre-ameloblasts from the pre...

Implant-retained dentures for full-arch rehabilitation: a case report comparing fixed and removable restorations.

Science.gov (United States)

Zafiropoulos, Gregory-George; Hoffman, Oliver

2011-01-01

Dental implants as abutments for full-arch restorations are a well-documented treatment modality. This report presents a case in which the patient was treated initially with fixed restorations supported by either implants or natural teeth and subsequently treated with a removable implant/telescopic crown-supported overdenture. Advantages and disadvantages of each approach are described and discussed. While the fixed restoration resulted in a functionally satisfactory treatment outcome, the patient was displeased with the esthetic appearance. The main concern was the unnaturally long tooth shape necessary to compensate for the insufficient alveolar ridge height. Replacement of the existing restoration with an implant-supported removable overdenture led to a functionally and esthetically acceptable result. When deciding whether to use a fixed or removable implant-supported full-arch restoration, a multitude of factors must be considered. Due to the possible need for additional surgical steps to enhance the esthetic appearance surrounding fixed restorations, removable implant-supported partial dentures often are the better choice.

Nonsurgical management of soft tissue around the restorations of maxillary anterior implants: a clinical report

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Seyedan K

2010-01-01

Full Text Available "nBackground and Aims: Soft tissue management with providing the esthetic for restoration of a single implant in the anterior maxilla is of great importance. Tissue training helps to develop a proper emergence profile and natural tooth appearance. The aim of this article was to report a nonsurgical management of undesirable contours of soft tissue around maxillary anterior implants to achieve an optimum appearance. "nMaterials and Methods: A 23-year-old female with congenital missing of maxillary lateral incisors, after completion of a fixed orthodontic treatment and gain enough space, received 2 dental implants. After second phase surgery and healing period, construction of the restorations was not possible through conventional method because of severe soft tissue collapse. In this case, soft tissue contours were corrected using a provisional restoration and then final restoration was made and delivered. "nConclusion: Tissue training with a provisional restoration helps to re-establish normal gingival tissue contours and interdental papillae around the restoration of maxillary anterior implants.

Radiopacity of dental restorative materials and cements

International Nuclear Information System (INIS)

Kang, Byung Chul; Yang, Hong So; Chung, Hyun Ju; Oh, Won Mann

1994-01-01

The radiopacity of six composite resins, three resin luting cements and ten filling materials were studied. The purpose was to obtain an indication of radiopacity value of different brands within each of these groups of materials and to show differences in radiopacities of filling materials and natural tooth structures. On radiographs, the optimal densities of standardized samples were determined by computer imaging system and radiopacity values of the materials were expressed in millimeter equivalent aluminum. Within to groups of materials studied, there was considerable variation in radiopacity. The composite resins of P-50, Zl00 and prisma AP. H displayed much higher radiopacities than aluminum. Panavia resin cement was shown to be similarly radiopaque to aluminum. Generally, the radiopacity of base and filling materials appeared to combined applications for restorative treatment of teeth, lower radiopacity can interfere with the diagnosis and detection of gaps near the restoration.

Radiopaque zones in the dentin beneath amalgam restorations

International Nuclear Information System (INIS)

You, Young Jun; Ahn, Hyung Kyu

1978-01-01

The purpose of the present investigation is determine how frequently radiopaque zones are seen on standard intraoral film and to research some other things about radiopaque bones. This study obtained the following results: 1. According to the standard intraoral films of the charts that were kept at the Dept. of Oral Diagnosis in Seoul National University Hospital, radiopaque zones were found in the rate of 4.1% among 1150 cases of amalgam-restored teeth that were treated at least two years ago. 2. Out of teeth that possessed radiopaque zones, 38.3% had radiolucent area between amalgam restoration and radiopaque zone. 3. Out of teeth that possessed radiopaque zones, 36.2% had cement base between amalgam restoration and radiopaque zone. 4. Out of teeth that possessed radiopaque zones, no tooth had periapical radiolucency. 5. Radiopaque zones were found more frequently in the mandibular teeth than the maxillary teeth. 6. According to the result of direct x-ray taking of 50 teeth that were treated at least 2 years ago, 6% had radiopaque zone.

Fluoridation and tooth wear in Irish adults.

LENUS (Irish Health Repository)

Burke, F M

2010-10-01

The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

A Survey of tooth morphology teaching methods employed in the United Kingdom and Ireland.

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Lone, M; McKenna, J P; Cryan, J F; Downer, E J; Toulouse, A

2018-01-15

Tooth morphology is a central component of the dental curriculum and is applicable to all dental specialities. Traditional teaching methods are being supplemented with innovative strategies to tailor teaching and accommodate the learning styles of the recent generation of students. An online survey was compiled and distributed to the staff involved in teaching tooth morphology in the United Kingdom and Ireland to assess the importance of tooth morphology in the dentistry curriculum and the methodologies employed in teaching. The results of the survey show that tooth morphology constitutes a small module in the dental curriculum. It is taught in the first 2 years of the dental curriculum but is applicable in the clinical years and throughout the dental career. Traditional teaching methods, lecture and practical, are being augmented with innovative teaching including e-learning via virtual learning environment, tooth atlas and e-books leading to blended learning. The majority of the schools teach both normal dental anatomy and morphologic variations of dental anatomy and utilise plastic teeth for practical and examination purposes. Learning the 3D aspects of tooth morphology was deemed important by most of the respondents who also agreed that tooth morphology is a difficult topic for the students. Despite being core to the dental curriculum, overall minimal time is dedicated to the delivery of tooth morphology, creating a reliance on the student to learn the material. New forms of delivery including computer-assisted learning tools should help sustain learning and previously acquired knowledge. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Management of foreign object in the root canal of central incisor tooth

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Mothanna Alrahabi

2014-01-01

Full Text Available There are several reports describing the impaction of foreign objects into the exposed pulp chambers and canals by patients, especially children as they often have the habit of inserting foreign objects in the oral cavity. These objects will become a potent source of infection.This case report describes the retrieval of a foreign object impacted into the root canal of a 12-year-old male patient who was referred to the endodontic specialty clinic at Taibah University College of Dentistry. The patient′s chief complaint was a pain in the upper left central tooth. Clinical examination revealed a complicated enamel-dentin fracture with a large caries cavity. A periapical radiographic image showed a radiopaque object in the root canal system. Stainless steel Hedstrom files were used to retrieve the object from the canal. Following a proper cleaning and shaping of the root canal system, an intra-canal calcium hydroxide dressing was placed for 1 week. The root canal system was then filled with sealer and gutta-percha using the lateral compaction technique and the tooth received an aesthetic restoration.

Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry

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Najeeb, Shariq; Khurshid, Zohaib; Zafar, Muhammad Sohail; Ajlal, Syed

2016-01-01

Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future. PMID:26642047

Mechanical behavior of bulk direct composite versus block composite and lithium disilicate indirect Class II restorations by CAD-FEM modeling.

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Ausiello, Pietro; Ciaramella, Stefano; Fabianelli, Andrea; Gloria, Antonio; Martorelli, Massimo; Lanzotti, Antonio; Watts, David C

2017-06-01

To study the influence of resin based and lithium disilicate materials on the stress and strain distributions in adhesive class II mesio-occlusal-distal (MOD) restorations using numerical finite element analysis (FEA). To investigate the materials combinations in the restored teeth during mastication and their ability to relieve stresses. One 3D model of a sound lower molar and three 3D class II MOD cavity models with 95° cavity-margin-angle shapes were modelled. Different material combinations were simulated: model A, with a 10μm thick resin bonding layer and a resin composite bulk filling material; model B, with a 70μm resin cement with an indirect CAD-CAM resin composite inlay; model C, with a 70μm thick resin cement with an indirect lithium disilicate machinable inlay. To simulate polymerization shrinkage effects in the adhesive layers and bulk fill composite, the thermal expansion approach was used. Shell elements were employed for representing the adhesive layers. 3D solid CTETRA elements with four grid points were employed for modelling the food bolus and tooth. Slide-type contact elements were used between the tooth surface and food. A vertical occlusal load of 600 N was applied, and nodal displacements on the bottom cutting surfaces were constrained in all directions. All the materials were assumed to be isotropic and elastic and a static linear analysis was performed. Displacements were different in models A, B and C. Polymerization shrinkage hardly affected model A and mastication only partially affected mechanical behavior. Shrinkage stress peaks were mainly located marginally along the enamel-restoration interface at occlusal and mesio-distal sites. However, at the internal dentinal walls, stress distributions were critical with the highest maximum stresses concentrated in the proximal boxes. In models B and C, shrinkage stress was only produced by the 70μm thick resin layer, but the magnitudes depended on the Young's modulus (E) of the inlay

Investigation of EPR signals on tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Pavlenko, A; Mironova-Ulmane, N; Polakov, M; Riekstina, D [Institute of Solid State Physics, University of Latvia, Riga (Latvia)

2007-12-15

Calcified tissues are involved in continues metabolic process in human organism exchanging a number of chemical elements with environment. The rate of biochemical reactions is tissue dependent and the slowest one at the tooth enamel, the most mineralized tissue of human organism. The long time stability and unique chemical composition make tooth enamel suitable for number of application. The assessment of individual radiation dose by Electron Paramagnetic Resonance (EPR) and evaluations of elemental composition by Instrumentation Neutron Activation Analysis (INAA) are the well known procedures where properties of tooth enamel intensively used. The current work is focused on investigation of EPR signals and determination of chemical composition on several teeth samples having different origin. The EPR spectra and INAA element content of milk tooth, caries tooth, and paradantose tooth have been compared to each other. The results showed that the intensity of EPR signal is much higher for the caries tooth than the for paradantose tooth that is in agreement with depleted Ca content.

Ultrasonographic Detection of Tooth Flaws

Science.gov (United States)

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

2010-02-01

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

[Development of electroforming apparatus for coronal restoration].

Science.gov (United States)

Watanabe, M; Sawada, T; Ukiya, M

1989-03-01

As dental technologies become highly developed, techniques have been more diversified. From as aspect of prosthodontic practice, both esthetic and functional requirements are emphasized for coronal restoration and consequently, these should be considered in the routine procedure. In fabrication of coronal restorations, metal, porcelain and resin are commonly used, and there exists the various disadvantages for metal cast method due to complicated processes by using different dental materials. Therefore, an electroforming apparatus was developed by us to replace the conventional procedure by a cathode rotary system. It was applied for coronal restorations to allow an electroforming directly on a working model. An experiment was successfully conducted to apply for a veneer crown on abutment tooth of upper central incisor on plaster model. The results were obtained as follows, 1. It was become possible to construct a metal framework by the electroforming. 2. Metal framework can be constructed on the same working model without a duplication of it. 3. The combined system for cathode rotation and liquid circulation could shorten the electroposition time, and allows a high current density extending to 50 A/dm2.

[Influence of different designs of marginal preparation on stress distribution in the mandibular premolar restored with endocrown].

Science.gov (United States)

Guo, Jing; Wang, Xiao-Yu; Li, Xue-Sheng; Sun, Hai-Yang; Liu, Lin; Li, Hong-Bo

2016-02-01

To evaluate the effect of different designs of marginal preparation on stress distribution in the mandibular premolar restored with endocrown using three-dimensional finite element method. Four models with different designs of marginal preparation, including the flat margin, 90° shoulder, 135° shoulder and chamfer shoulder, were established to imitate mandibular first premolar restored with endocrown. A load of 100 N was applied to the intersection of the long axis and the occlusal surface, either parallel or with an angle of 45° to the long axis of the tooth. The maximum values of Von Mises stress and the stress distribution around the cervical region of the abutment and the endocrown with different designs of marginal preparation were analyzed. The load parallel to the long axis of the tooth caused obvious stress concentration in the lingual portions of both the cervical region of the tooth tissue and the restoration. The stress distribution characteristics on the cervical region of the models with a flat margin and a 90° shoulder were more uniform than those in the models with a 135° shoulder and chamfer shoulder. Loading at 45° to the long axis caused stress concentration mainly on the buccal portion of the cervical region, and the model with a flat margin showed the most favorable stress distribution patterns with a greater maximum Von Mises stress under this circumstance than that with a parallel loading. Irrespective of the loading direction, the stress value was the lowest in the flat margin model, where the stress value in the cervical region of the endocrown was greater than that in the counterpart of the tooth tissue. The stress level on the enamel was higher than that on the dentin nearby in the flat margin model. From the stress distribution point of view, endocrowns with flat margin followed by a 90° shoulder are recommended.

Restoration of a vertical alveolar bone defect by orthodontic relocation of a mesially impacted mandibular first molar.

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Kim, Sung-Jin; Kim, Jin-Wook; Choi, Tae-Hyun; Lee, Kee-Joon

2015-04-01

An impacted mandibular first molar tends to cause serious bone defects of the adjacent teeth. When choosing between the 2 typical treatment options-extraction or orthodontic relocation of the impacted tooth-the decision should be based on assessment of the prognosis. A 22-year-old man with severe mesioangulation and impaction of the mandibular first molar and a related vertical bone defect on the distal side of the second premolar was treated with extraction of the second molar and orthodontic relocation of the first molar with a retromolar miniscrew. Comprehensive orthodontic treatment involving premolar extraction was conducted. Strategic extraction of the molar and adequate orthodontic movement helped to restore the bone structure on the affected side. This case report suggests the effectiveness of restoration of bone defects by using viable periodontal tissues around the impacted tooth for the longevity of the periodontium. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

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Y. Gui

2014-01-01

Full Text Available Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

A 1-year randomised controlled trial comparing zirconia versus metal-ceramic implant supported single-tooth restorations

DEFF Research Database (Denmark)

Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten

2011-01-01

, by blinded assessors. RESULTS: One-year after loading, no patient dropped out and no implant failed, though one MC restoration had to be remade. The marginal bone loss was not significantly different between AC and MC restorations (AC: mean 0.08 mm, SD 0.25; MC: mean 0.10 mm, SD 0.17). Seven out of 10...

Evaluation of Different Restoration Combinations Used in the Reattachment of Fractured Teeth: A Finite Element Analysis

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Nagihan Guven

2018-01-01

Full Text Available Objective. The purpose of this study was to test different restoration combinations used for constructing fractured endodontically treated incisors by reattaching their fractured fragments. Methods. Seven types of 3-D FEM mathematical root canal-filled models were generated, simulating cases of (OB reattaching fractured fragments; (CrPL reattaching fractured fragments + ceramic palatinal laminate; (CmPL reattaching fractured fragments + composite palatinal laminate; (CM reattaching fractured fragments + coronal 1/3 of the root was filled using core material; (BP reattaching fractured fragments + glass fiber post; (CP composite resin restoration + glass fiber post; and (OC composite resin restoration. A 100-N static oblique force was applied to the simulated teeth with 135° on the node at 2 mm above the cingulum to analyze the stress distribution at the tooth. Results. For enamel tissue, the highest stress values were observed in model BP, and the lowest stress values were observed in model CmPL. For dentine tissue, the highest stress concentrations were observed around the fracture line for all models. Conclusions. Reattachment of fractured fragments by bonding may be preferred as a restoration option for endodontically treated incisors; also, palatinal laminate decreases the stress values at tooth tissues, especially at the enamel and the fracture line.

Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

Science.gov (United States)

Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

2016-01-01

Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

Evolution of high tooth replacement rates in sauropod dinosaurs.

Science.gov (United States)

D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

2013-01-01

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. 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. 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.

Evolution of high tooth replacement rates in sauropod dinosaurs.

Directory of Open Access Journals (Sweden)

Michael D D'Emic

Full Text Available 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

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

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Shepperd Sasha

2007-12-01

Full Text Available Abstract Background A frequent encounter in clinical practice is the middle-aged adult patient complaining of a toothache caused by the spread of a carious infection into the tooth's endodontic complex. Decisions about the range of treatment options (conventional crown with a post and core technique (CC, a single tooth implant (STI, a conventional dental bridge (CDB, and a partial removable denture (RPD have to balance the prognosis, utility and cost. Little is know about the utility patients attach to the different treatment options for an endontically abscessed mandibular molar and maxillary incisor. We measured patients' dental-health-state utilities and ranking preferences of the treatment options for these dental problems. Methods Forty school teachers ranked their preferences for conventional crown with a post and core technique, a single tooth implant, a conventional dental bridge, and a partial removable denture using a standard gamble and willingness to pay. Data previously reported on treatment prognosis and direct "out-of-pocket" costs were used in a decision-tree and economic analysis Results The Standard Gamble utilities for the restoration of a mandibular 1st molar with either the conventional crown (CC, single-tooth-implant (STI, conventional dental bridge (CDB or removable-partial-denture (RPD were 74.47 [± 6.91], 78.60 [± 5.19], 76.22 [± 5.78], 64.80 [± 8.1] respectively (p The standard gamble utilities for the restoration of a maxillary central incisor with a CC, STI, CDB and RPD were 88.50 [± 6.12], 90.68 [± 3.41], 89.78 [± 3.81] and 91.10 [± 3.57] respectively (p > 0.05. Their respective willingness-to-pay ($CDN were: 1,782.05 [± 361.42], 1,871.79 [± 349.44], 1,605.13 [± 348.10] and 1,351.28 [± 368.62]. A statistical difference was found between the utility of treating a maxillary central incisor and mandibular 1st-molar (p The expected-utility-value for a 5-year prosthetic survival was highest for the CDB and the

Interdisciplinary management for restoration of function and esthetics in a patient with hereditary amelogenesis imperfecta

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Sushma Dhiman

2015-01-01

Full Text Available Amelogenesis imperfecta (AI is a type of the hereditary disorder which is expressed as a group of conditions causing developmental alterations in the structure of enamel. It is associated with a reduction of oral health-related quality-of-life, has an impact on psychological well-being, and leads to various physiological problems. Children or adults with AI express varying degree of malocclusions either in the form of crowding, impacted teeth, spacing, retained teeth, reduced vertical height due to abnormal tooth structure or undue tooth loss. Orthodontic treatment should precede esthetic rehabilitation. Proper diagnosis of the case is quintessential to provide durable functional and esthetic result to these patients, improving the quality of their lives. We present a case of interdisciplinary management for restoring function and esthetics in a patient with hereditary AI of the hypoplastic type accompanied with tooth impaction and some other dental anomalies.

Mechanical performance of encapsulated restorative glass-ionomer cements for use with Atraumatic Restorative Treatment (ART).

Science.gov (United States)

Molina, Gustavo Fabián; Cabral, Ricardo Juan; Mazzola, Ignacio; Lascano, Laura Brain; Frencken, Jo E

2013-01-01

The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths exists between: (1) The EQUIA system and (2) The Chemfil Rock (encapsulated glass-ionomers; test materials) and the Fuji 9 Gold Label and the Ketac Molar Easymix (hand-mixed conventional glass-ionomers; control materials); (3) The EQUIA system and Chemfil Rock. Specimens for testing flexural (n = 240) and diametral tensile (n=80) strengths were prepared according to standardized specifications; the compressive strength (n=80) was measured using a tooth-model of a class II ART restoration. ANOVA and Tukey B tests were used to test for significant differences between dependent and independent variables. The EQUIA system and Chemfil Rock had significantly higher mean scores for all the three strength variables than the Fuji 9 Gold Label and Ketac Molar Easymix (α=0.05). The EQUIA system had significant higher mean scores for diametral tensile and flexural strengths than the Chemfil Rock (α=0.05). The two encapsulated high-viscosity glass-ionomers had significantly higher test values for diametral tensile, flexural and compressive strengths than the commonly used hand-mixed high-viscosity glass-ionomers.

Fluoride-releasing restorative materials and secondary caries.

Science.gov (United States)

Hicks, John; Garcia-Godoy, Franklin; Donly, Kevin; Flaitz, Catherine

2003-03-01

Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. Risk factors for secondary caries are similar to those for primary caries development. Unfortunately, it is not possible to accurately predict which patients are at risk for restoration failure. During the past several decades, fluoride-releasing dental materials have become a part of the dentist's armamentarium. Considerable fluoride is released during the setting reaction and for periods up to eight years following restoration placement. This released fluoride is readily taken up by the cavosurface tooth structure, as well as the enamel and root surfaces adjacent to the restoration. Resistance against caries along the cavosurface and the adjacent smooth surface has been shown in both in vitro and in vivo studies. Fluoride-releasing dental materials provide for improved resistance against primary and secondary caries in coronal and root surfaces. Plaque and salivary fluoride levels are elevated to a level that facilitates remineralization. In addition, the fluoride released to dental plaque adversely affects the growth of lactobacilli and mutans streptococci by interference with bacterial enzyme systems. Fluoride recharging of these dental materials is readily achieved with fluoridated toothpastes, fluoride mouthrinses, and other sources of topical fluoride. This allows fluoride-releasing dental materials to act as intraoral fluoride reservoirs. The improvement in the properties of dental materials with the ability to release fluoride has improved dramatically in the past decade, and it is anticipated that in the near future the vast majority of restorative procedures will employ fluoride-releasing dental materials as bonding agents, cavity liners, luting agents, adhesives for orthodontic brackets, and definitive restoratives.

Adhesive/Dentin Interface: The Weak Link in the Composite Restoration

Science.gov (United States)

Spencer, Paulette; Ye, Qiang; Park, Jonggu; Topp, Elizabeth M.; Misra, Anil; Marangos, Orestes; Wang, Yong; Bohaty, Brenda S.; Singh, Viraj; Sene, Fabio; Eslick, John; Camarda, Kyle; Katz, J. Lawrence

2010-01-01

Results from clinical studies suggest that more than half of the 166 million dental restorations that were placed in the United States in 2005 were replacements for failed restorations. This emphasis on replacement therapy is expected to grow as dentists use composite as opposed to dental amalgam to restore moderate to large posterior lesions. Composite restorations have higher failure rates, more recurrent caries, and increased frequency of replacement as compared to amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and premature failure. Under in vivo conditions the bond formed at the adhesive/dentin interface can be the first defense against these noxious, damaging substances. The intent of this article is to review structural aspects of the clinical substrate that impact bond formation at the adhesive/dentin interface; to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface. PMID:20195761

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

Science.gov (United States)

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

2015-06-01

Endodontic treatment of tooth formation anomalies is a challenge to clinicians and as such requires a complete understanding of the aberrant root canal anatomy followed by careful root canal disinfection and obturation. Here, we report the use of a 3-dimensional (3D) printed physical tooth model including internal root canal structures for the endodontic treatment of a challenging tooth anomaly. A 12-year-old boy was referred for endodontic treatment of tooth #8. The tooth showed class II mobility with swelling and a sinus tract in the buccal mucosa and periapical radiolucency. The tooth presented a very narrow structure between the crown and root by distal concavity and a severely dilacerated root. Moreover, a perforation site with bleeding and another ditching site were identified around the cervical area in the access cavity. A translucent physical tooth model carrying the information on internal root canal structures was built through a 3-step process: data acquisition by cone-beam computed tomographic scanning, virtual modeling by image processing, and manufacturing by 3D printing. A custom-made guide jig was then fabricated to achieve a safe and precise working path to the root canal. Endodontic procedures including access cavity preparation were performed using the physical tooth model and the guide jig. At the 7-month follow-up, the endodontically treated tooth showed complete periapical healing with no clinical signs and symptoms. This case report describes a novel method of endodontic treatment of an anomalous maxillary central incisor with the aid of a physical tooth model and a custom-made guide jig via 3D printing technique. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Primary culprit for tooth loss!!

OpenAIRE

Nuvvula, Sailavanya; Chava, Vijay Kumar; Nuvvula, Sivakumar

2016-01-01

Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A quest...

Effects of hydrogen peroxide bleaching strip gels on dental restorative materials in vitro: surface microhardness and surface morphology.

Science.gov (United States)

Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

2004-01-01

This study examined the effects of peroxide tooth bleaching, including Crest Whitestrips hydrogen peroxide gel treatments, on the surface hardness and morphology of common dental restorative treatments. American Dental Association (ADA) recommended dental restorative materials, including amalgam, dental gold, porcelain, glass ionomer, and composites, were prepared according to manufacturers' instructions. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching gels, which utilize hydrogen peroxide as the in situ bleaching source, and several commercial carbamide peroxide bleaching gels. Control treatments included placebo gels and an untreated group. Crest Whitestrips bleaching included treatment exposures simulating recommended clinical exposures (14 hours), along with excess bleaching simulating exposure to five times suggested Crest Whitestrips use. At the conclusion of treatments, surface microhardness measures and surface morphological assessments with standard and variable pressure (VP-) SEMs were conducted to assess the effects of bleaching exposure on the surface morphology and structural integrity of the restoratives. Surface microhardness and SEM measures revealed no significant deleterious effects on the restoration surfaces from Whitestrips gels. These results confirm that tooth bleaching from the selected commercial hydrogen peroxide or carbamide peroxide bleaching systems does not produce changes in surface morphology or microhardness of common dental restorative materials. These results support the clinical safety of the selected commercial bleaching systems to the oral environment, matching results obtained from long-term use of these ingredients applied in dental offices and available in commercial formulations.

Prospective assessment of CAD/CAM zirconia abutment and lithium disilicate crown restorations: 2.4 year results.

Science.gov (United States)

Cooper, Lyndon F; Stanford, Clark; Feine, Jocelyne; McGuire, Michael

2016-07-01

Single-tooth implant restorations are commonly used to replace anterior maxillary teeth. The esthetic, functional, and biologic outcomes are, in part, a function of the abutment and crown. The purpose of this clinical study was to describe the implant, abutment, and crown survival and complication rates for CAD/CAM zirconia abutment and lithium disilicate crown restorations for single-tooth implants. As part of a broader prospective investigation that enrolled and treated 141 participants comparing tissue responses at the conical interface (CI; AstraTech OsseoSpeed), flat-to-flat interface (FI; NobelSpeedy), and platform-switch interface (PS; NanoTite Certain Prevail) of single-tooth implants, computer-aided design and computer-aided manufacturing (CAD/CAM) zirconia abutments (ATLANTIS Abutment) and cemented lithium disilicate (e.max) crowns were used in the restoration of all implants. After 2.4 years in function (3 years after implant placement), the implant, abutment, and crown of 110 participants were evaluated. Technical and biologic complications were recorded. Demographic results were tabulated as percentages with mean values and standard deviations. Abutment survival was calculated with the Kaplan-Meier method. After 2.4 years, no abutments or crowns had been lost. Abutment complications (screw loosening, screw fracture, fracture) were absent for all 3 implant groups. Crown complications were limited to 2 crowns debonding and 1 with excess cement (2.5%). Five biological complications (4.0%) were recorded. The overall complication rate was 6.5%. CAD/CAM zirconia abutments restored with cemented lithium disilicate crowns demonstrated high survival on 3 different implant-abutment interface designs. No abutment or abutment screw fracture occurred. The technical complications observed after 2.4 years were minor and reversible. The use of CAD/CAM zirconia abutments with cemented lithium disilicate crowns is associated with high technical and biologic success at 2

Evidence-based concepts and procedures for bonded inlays and onlays. Part II. Guidelines for cavity preparation and restoration fabrication.

Science.gov (United States)

Rocca, Giovanni Tommaso; Rizcalla, Nicolas; Krejci, Ivo; Dietschi, Didier

2015-01-01

The second part of this article series presents an evidence-based update of clinical protocols and procedures for cavity preparation and restoration selection for bonded inlays and onlays. More than ever, tissue conservation dictates preparation concepts, even though some minimal dimensions still have to be considered for all restorative materials. In cases of severe bruxism or tooth fragilization, CAD/CAM composite resins or pressed CAD/CAM lithium disilicate glass ceramics are often recommended, although this choice relies mainly on scarce in vitro research as there is still a lack of medium- to long-term clinical evidence. The decision about whether or not to cover a cusp can only be made after a multifactorial analysis, which includes cavity dimensions and the resulting tooth biomechanical status, as well as occlusal and esthetic factors. The clinical impact of the modern treatment concepts that were outlined in the previous article - Dual Bonding (DB)/Immediate Dentin Sealing (IDS), Cavity Design Optimization (CDO), and Cervical Margins Relocation (CMR) - are described in detail in this article and discussed in light of existing clinical and scientific evidence for simpler, more predictable, and more durable results. Despite the wide choice of restorative materials (composite resin or ceramic) and techniques (classical or CAD/CAM), the cavity for an indirect restoration should meet five objective criteria before the impression.

Influence of artificial aging on the load-bearing capability of straight or angulated zirconia abutments in implant/tooth-supported fixed partial dentures.

Science.gov (United States)

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

2010-01-01

The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments used in ZirDesign (Astra Tech) implant/tooth-supported fixed partial dentures (FPDs) in the maxilla. Four different test groups (n = 8) representing anterior implant/tooth-supported FPDs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (maxillary left central incisor) from a prosthetic point of view, which allowed for the use of a straight, prefabricated zirconia abutment. Groups 3 and 4 simulated a situation with a compromised implant position that required an angulated (20-degree) abutment. OsseoSpeed implants (4.5 3 13 mm, Astra Tech) as well as metal tooth analogs (maxillary right lateral incisor) with simulated periodontal mobility were mounted in polymethyl methacrylate. The FPDs (chromium-cobalt alloy) were cemented with glass ionomer. Groups 2 and 4 were thermomechanically loaded and subjected to static loading until failure. Statistical analysis of force data at the fracture site was performed using nonparametric tests. All samples survived thermomechanical loading. Artificial aging did not lead to a significant decrease in load-bearing capacity in either the straight abutments or the angulated abutments. The restorations that used angulated abutments exhibited higher fracture loads than the restorations with straight abutments (group 1: 209.13 ± 39.11 N; group 2: 233.63 ± 30.68 N; group 3: 324.62 ± 108.07 N; group 4: 361.75 ± 73.82 N). This difference in load-bearing performance was statistically significant, both with and without artificial aging. All abutment fractures occurred below the implant shoulder. Compensation for angulated implant positions with an angulated zirconia abutment is possible without reducing the load-bearing capacity of implant/tooth-supported anterior FPDs.

High-risk esthetically driven restoration: begin with the end in mind.

Science.gov (United States)

Ricciardi, Michael T; Pizzi, Peter

2013-03-01

A high-risk esthetically driven restorative case requires the dental team, along with the patient, to have a clear vision of the final outcome. In this case of a 33-year-old woman who wanted to improve her smile, esthetic problems stemmed from a retained deciduous maxillary left canine along with an impacted tooth No. 11. Among a number of concerns was the shape and color of the deciduous canine and the uneven length of the maxillary central incisors. A treatment plan that included orthodontics with removable aligners, occlusal adjustment, composite restorations, extraction and implant placement, indirect porcelain veneers, and a custom abutment and PFM crown was successfully executed in four phases over the course of more than 4 years.

Atypical Odontalgia (Phantom Tooth Pain)

Science.gov (United States)

... atypical facial pain, phantom tooth pain, or neuropathic orofacial pain, is characterized by chronic pain in a tooth ... such as a specialist in oral medicine or orofacial pain. The information contained in this monograph is for ...

Posterior indirect adhesive 
restorations: updated indications 
and the Morphology Driven 
Preparation Technique.

Science.gov (United States)

Veneziani, Marco

The aim of this article is to identify the indications for adhesively cemented restorations and to provide a correct step-by-step protocol for clinicians. New cavity preparation principles are based on morphological considerations in terms of geometry (maximum profile line and inclination of cusp lines), and structure (dentin concavity and enamel convexity). In this article, we discuss previous preparation concepts that were not designed purely for adhesive restorations and were therefore not conservative enough or suitable for adhesive procedures. The novel cavity shape consists of continuous inclined plane cavity margins (hollow chamfer or concave bevel) on axial walls, whenever they are coronal to the equatorial tooth line. A 1.2 mm-thick butt-joint preparation is performed in the interproximal box and on the axial walls when the margins are apical to the equatorial line. The occlusal surface is anatomically prepared, free of slots and angles. The author's suggestion is to avoid shoulder finish line preparation around cusps, occlusal slots, and pins, as they are less conservative, incompatible with adhesive procedures, and involve unnecessary dentin exposure. The clinical advantages of this new "anatomic" preparation design are 1) improving adhesion quality (optimizing the cutting of enamel prisms, and increasing the available enamel surface); 2) minimizing dentin exposure; 3) maximizing hard tissue preservation (the cavity being designed for cementation with reinforced composite resins, improvement of flow, and removal of excess material); 4) optimization of esthetic integration due to the inclined plane design, which permits a better blending at the transition area between tooth and restoration. These preparation principles may be effectively used for all adhesively cemented restorations, both according to traditional concepts (inlay, onlay, overlay) and new ones (additional overlay, occlusal-veneer, overlay-veneer, long-wrap overlay, adhesive crown). Thus, a

Tooth breakage in patients injected with 224Ra

International Nuclear Information System (INIS)

Sonnabend, E.; Spiess, H.; Mays, C.W.

1986-01-01

Tooth breakage has been common among the 224 Ra patients, especially those injected as teenagers. The fracture of 1 or more teeth was reported by 26% (8/31) of boys and 23% (7/30) of girls injected with 224 Ra at 16-20 years of age. Combining results from all age groups, the incidence of tooth fractures increased significantly with dose (P=0.01). Unlike the normal loss of permanent teeth by periodontal disease, in which the entire tooth is lost, the tooth loss following 224 Ra injection was primarily from tooth resorption near the gum line causing the tooth crowns to break off easily. Eventually the tooth roots may either become incorporated into the jawbone or are resorbed and replaced with bone. These tooth fractures resembled those observed in the U.S. radium dial painters and in dogs injected with bone-seeking α-emitters. (orig.)

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

Science.gov (United States)

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

2015-01-01

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

Autotransplantation of Third Molars With Platelet-Rich Plasma for Immediate Replacement of Extracted Non-Restorable Teeth: A Case Series.

Science.gov (United States)

Gonzalez-Ocasio, Jorge; Stevens, Mark

2017-09-01

The aim of this study was to examine the use of platelet-rich plasma (PRP) for autotransplantation of third molars as a successful technique to provide immediate tooth structure for space maintenance and masticatory function when premature loss of a permanent tooth occurs and other dental restorative options are not indicated. This study included 10 healthy patients 10 to 17 years of age with at least 1 immature third molar (one to two thirds of root formation) used to replace extracted non-restorable teeth. Eleven third molars were transplanted and adapted to sockets of the extracted teeth with the adjunct of PRP. Transplanted teeth were stabilized to the adjacent teeth using orthodontic wires and dental composite for 1 month. Patients were followed for 1 year. Function, tooth vitality, root development, and periodontal health were recorded. All 10 patients had functioning asymptomatic transplanted teeth, with physiologic tooth mobility after splint removal at 1 month and after 1 year. All 10 patients had positive tooth vitality (by cold test) at 3, 6, and 12 months; all transplants showed positive root development (average growth, 2.01 mm) confirmed and measured using periapical radiographs. No patients required root canal therapy at any point in the study. Periodontal assessments were performed at the scheduled follow-up appointments with circumferential periodontal probing. Periodontal health was maintained because probing depths were shallower than 4 mm during the 1-year follow-up. Autotransplantation of immature third molars with PRP shows excellent results and should be considered a viable option for premature loss of permanent molars. PRP might have other advantages, such as root promotion and neurosensory development. Published by Elsevier Inc.

The effect of nano-hydroxyappatite solution on the permanent tooth remineralization following exposure to soft beer (in situ

Directory of Open Access Journals (Sweden)

Haghgoo Roza

2015-01-01

Full Text Available   Background and Aims: The main cause of erosion is acid exposure . Side effects of erosion necessitate therapeutic agents’ uses. The aim of this study was to investigate the effects of nano- hydroxy apatite in tooth remineralization following exposure to soft beer.   Materials and Methods: This in vitro experimental study was conducted on 18 human impacted third molars that had been surgically extracted. The microhardness of specimens was measured. Then teeth were exposed to soft beer and their secondary microhardness was measured. The teeth were divided into 2 groups (water and nano-hydroxy apatite solution and were placed on 9 orthodontics appliances and delivered to 9 volunteers. These volunteers placed the tooth on one side in water for 5 minutes and the tooth in opposite side in nano-hydroxyapatite solution. This application was repeated 6 times a day for 10 days. The microhardness of teeth was measured again. Data were analyzed using Paired T-test.   Results: The tooth enamel microhardness reduced after exposure to soft beer significantly (P=0.04. The microhardness of 9 teeth after being in water showed significant changes (P=0.012. The microhardness of 9 teeth significantly changed after exposure to nano -hydroxyapatite solution (P=0.001 .   Conclusion: Based on the results of this study, 10% solution of nano- hydroxy appatite could restore the erosive lesions .

Big rock point restoration project BWR major component removal, packaging and shipping - planning and experience

International Nuclear Information System (INIS)

Milner, T.; Dam, S.; Papp, M.; Slade, J.; Slimp, B.; Nurden, P.

2001-01-01

The Big Rock Point boiling water reactor (BWR) at Charlevoix, MI was permanently shut down on August 29th 1997. In 1999 BNFL Inc.'s Reactor Decommissioning Group (RDG) was awarded a contract by Consumers Energy (CECo) for the Big Rock Point (BRP) Major Component Removal (MCR) project. BNFL Inc. RDG has teamed with MOTA, Sargent and Lundy and MDM Services to plan and execute MCR in support of the facility restoration project. The facility restoration project will be completed by 2005. Key to the success of the project has been the integration of best available demonstrated technology into a robust and responsive project management approach, which places emphasis on safety and quality assurance in achieving project milestones linked to time and cost. To support decommissioning of the BRP MCR activities, a reactor vessel (RV) shipping container is required. Discussed in this paper is the design and fabrication of a 10 CFR Part 71 Type B container necessary to ship the BRP RV. The container to be used for transportation of the RV to the burial site was designed as an Exclusive Use Type B package for shipment and burial at the Barnwell, South Carolina (SC) disposal facility. (author)

Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

Directory of Open Access Journals (Sweden)

R. Ebru Tirali

2013-01-01

Full Text Available Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

Autotransplantation donor tooth site harvesting using piezosurgery

OpenAIRE

Ylikontiola, Leena P.; S?ndor, George K.

2016-01-01

Abstract Background: The harvesting of a tooth as a candidate for tooth autotransplantation requires that the delicate dental tissues around the tooth be minimally traumatized. This is especially so for the periradicular tissues of the tooth root and the follicular tissues surrounding the crown. The aim of this report is to describe the use of piezosurgery as an attempt at morbidity reduction in the harvesting of teeth for autotransplantation. Methods: A piezosurgical handpiece and its ...

Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

International Nuclear Information System (INIS)

Gomez, Jorge A.; Kinoshita, Angela; Leonor, Sergio J.; Belmonte, Gustavo C.; Baffa, Oswaldo

2011-01-01

In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

Energy Technology Data Exchange (ETDEWEB)

Gomez, Jorge A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Kinoshita, Angela [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Leonor, Sergio J. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Belmonte, Gustavo C. [Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Baffa, Oswaldo, E-mail: baffa@usp.br [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

2011-09-15

In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

Proteomic analysis of human tooth pulp: proteomics of human tooth.

Science.gov (United States)

Eckhardt, Adam; Jágr, Michal; Pataridis, Statis; Mikšík, Ivan

2014-12-01

The unique pulp-dentin complex demonstrates strong regenerative potential, which enables it to respond to disease and traumatic injury. Identifying the proteins of the pulp-dentin complex is crucial to understanding the mechanisms of regeneration, tissue calcification, defense processes, and the reparation of dentin by dental pulp. The lack of knowledge of these proteins limits the development of more efficient therapies. The proteomic profile of human tooth pulp was investigated and compared with the proteome of human dentin and blood. The samples of tooth pulp were obtained from 5 sound permanent human third molars of 5 adults (n = 5). The extracted proteins were separated by 2-dimensional gel electrophoresis, analyzed by nano-liquid chromatography tandem mass spectrometry, and identified by correlating mass spectra to the proteomic databases. A total of 342 proteins were identified with high confidence, and 2 proteins were detected for the first time in an actual human sample. The identified tooth pulp proteins have a variety of functions: structural, catalytic, transporter, protease activity, immune response, and many others. In a comparison with dentin and blood plasma, 140 (pulp/dentin) shared proteins were identified, 37 of which were not observed in plasma. It can be suggested that they might participate in the unique pulp-dentin complex. This proteomic investigation of human tooth pulp, together with the previously published study of human dentin, is one of the most comprehensive proteome lists of human teeth to date. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Test Tube Tooth: The Next Big Thing.

Science.gov (United States)

Yadav, Preeti; Tahir, Mohammed; Yadav, Harsh; Sureka, Rakshit; Garg, Aarti

2016-06-01

Unlike some vertebrates and fishes, humans do not have the capacity for tooth regeneration after the loss of permanent teeth. Although artificial replacement with removable dentures, fixed prosthesis and implants is possible through advances in the field of prosthetic dentistry, it would be ideal to recreate a third set of natural teeth to replace lost dentition. For many years now, researchers in the field of tissue engineering have been trying to bioengineer dental tissues as well as whole teeth. In order to attain a whole tooth through dental engineering, that has the same or nearly same biological, mechanical and physical properties of a natural tooth, it's necessary to deal with all the cells and tissues which are concerned with the formation, maintenance and repair of the tooth. In this article we review the steps involved in odontogenesis or organogenesis of a tooth and progress in the bioengineering of a whole tooth.

Implant replacement of the maxillary central incisor utilizing a modified ceramic abutment (Thommen SPI ART) and ceramic restoration.

Science.gov (United States)

Schneider, Robert

2008-01-01

The prosthetic restoration of a missing anterior tooth with a dental implant is a challenge. Treatment coordination with a multidisciplinary team is critical in the successful outcome of this type of patient treatment. Newer surgical treatment modalities in the management of hard and soft tissues are becoming common, with very good predictability and long-term stability. Additionally, the use of advanced dental technology and materials such as sintered zirconium allows the restorative practitioner the opportunity to fabricate an esthetic, precise-fitting, biocompatible, and strong definitive prosthesis for the patient, with good longevity. The use of an all-ceramic abutment and restoration is described, along with the "soft tissue sculpting" procedure through the use of a custom provisional restoration. The relative ease and convenience of the procedure is also illustrated.

Longevity of posterior composite restorations: not only a matter of materials.

Science.gov (United States)

Demarco, Flávio F; Corrêa, Marcos B; Cenci, Maximiliano S; Moraes, Rafael R; Opdam, Niek J M

2012-01-01

Resin composites have become the first choice for direct posterior restorations and are increasingly popular among clinicians and patients. Meanwhile, a number of clinical reports in the literature have discussed the durability of these restorations over long periods. In this review, we have searched the dental literature looking for clinical trials investigating posterior composite restorations over periods of at least 5 years of follow-up published between 1996 and 2011. The search resulted in 34 selected studies. 90% of the clinical studies indicated that annual failure rates between 1% and 3% can be achieved with Class I and II posterior composite restorations depending on several factors such as tooth type and location, operator, and socioeconomic, demographic, and behavioral elements. The material properties showed a minor effect on longevity. The main reasons for failure in the long term are secondary caries, related to the individual caries risk, and fracture, related to the presence of a lining or the strength of the material used as well as patient factors such as bruxism. Repair is a viable alternative to replacement, and it can increase significantly the lifetime of restorations. As observed in the literature reviewed, a long survival rate for posterior composite restorations can be expected provided that patient, operator and materials factors are taken into account when the restorations are performed. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

[Application of single-retainer all-ceramic resin-bonded fixed partial denture in replacing single anterior tooth].

Science.gov (United States)

Lili, Yang; Debiao, Du; Ruoyu, Ning; Deying, Chen; Junling, Wu

2017-08-01

Objective In this study, we aimed to evaluate the clinical effect of single-retainer all-ceramic resin-bonded fixed partial denture (RBFPD) on the single anterior tooth loss patients. Methods A total of 20 single-retainer all-ceramic RBFPD
were fabricated and evaluated in a two-year follow-up observation. The restorations were examined on the basis of the American Public Health Association (APHA) criteria. Results A total of 20 single-retainer all-ceramic RBFPD achieved class A evaluation after a six-month follow-up observation. One single-retainer all-ceramic RBFPD was classified as class B for secondary caries after a one-year follow-up observation. After a two-year follow-up observation, one single-retainer all-ceramic RBFPD was classified as class B because of secondary caries, and one single-retainer all-ceramic RBFPD was classified as class B because of fracture. Conclusion Single-retainer all-ceramic RBFPD is a promising and optional method in replacing single anterior tooth.

Mummy Restoration Project Among the Anga of Papua New Guinea.

Science.gov (United States)

Beckett, Ronald G; Nelson, Andrew J

2015-06-01

We report on a unique Mummy restoration project among the anga of papua new guinea. Moimango was a village leader who had gone through the smoked body mummification process about 50 years ago. His smoked body has been displayed, alongside other ancestors, on a cliff niche gallery 308 m (1011 feet) above Koke Village. Although somewhat protected by an overhang, Moimango suffered a great deal of deterioration as he has been unprotected and exposed to the elements. The goals of our 2010 expedition to Koke Village was to assess the efficacy of restoration efforts applied to Moimango initiated by the authors and villagers of Koke in 2008. The restoration process used materials native to the local jungles. We examined Moimango for additional restoration challenges that may have arisen since the 2008 expedition. We discovered that many of the restoration techniques developed and applied in 2008 held up well. We found that the anatomical supports developed from native tapa and kumaka sap were still in place and effective, as well as our lichen eradication method of a suca slurry applied in 2008. Of particular importance was the stability of Moimago's head, which prior to restoration, was held in place by only the mummified muscle and integument of the lateral and posterior neck region. Endoscopic evaluation demonstrated disarticulated C1 and C2 vertebrae. New restoration challenges included construction of a new display chair, realignment and securing of the mandible, replacing and securing a loose tooth, repatching, and recoating with ritualistic red ochre clay. © 2015 Wiley Periodicals, Inc.

Multiphoton microscopy imaging of developing tooth germs

Directory of Open Access Journals (Sweden)

Pei-Yu Pan

2014-01-01

Conclusion: In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.

A Radiographic Study of Fused and Geminated Tooth

Energy Technology Data Exchange (ETDEWEB)

Park, Chul Jae; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyunhee University, Seoul (Korea, Republic of)

1990-02-15

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

A Radiographic Study of Fused and Geminated Tooth

International Nuclear Information System (INIS)

Park, Chul Jae; Lee, Sang Rae

1990-01-01

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats.

Science.gov (United States)

Hosokawa, Yoichiro; Sakakura, Yasunori; Irie, Kazuharu; Kudo, Kohsei; Kashiwakura, Ikuo

2010-01-01

Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing.

Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats

International Nuclear Information System (INIS)

Hosokawa, Yoichiro; Kudo, Kohsei; Kashiwakura, Ikuo; Sakakura, Yasunori; Irie, Kazuharu

2010-01-01

Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing. (author)

Effects of Model Salivary Esterases and MMP Inhibition on the Restoration's Marginal Integrity and Potential Degradative Contribution of Cariogenic Bacteria

Science.gov (United States)

Huang, Bo

Enzyme-catalyzed degradation of the restoration-tooth interface compromises interfacial integrity, thereby contributing to secondary caries, which is a major cause of resin-based restoration failure. It is hypothesized that in addition to salivary esterases, the cariogenic bacterium Streptococcus mutans has specific esterases that degrade the resin-dentin interface, releasing biodegradation by- products (BBPs) such as bis-hydroxy-propoxy-phenyl-propane (BisHPPP). In turn, BisHPPP affects S. mutans by stimulating the expression of esterases. Another hypothesis is that the biostability of the resin-dentin interface is affected by simulated salivary esterases, dentinal matrix metalloproteinase (MMP) inhibition, and restorative materials. To test the first hypothesis, putative esterase genes in S. mutans UA159 were identified, purified, and characterized. SMU_118c was identified as the dominant esterase in S. mutans UA159 and showed a similar hydrolytic activity profile to salivary esterases. BisHPPP upregulated expression of the SMU_118c gene and related protein in a concentration-dependent manner. This positive feedback process could accelerate the degradation of the restoration-tooth interface and lead to premature restoration failure. To test the second hypothesis, an in vitro model was established to evaluate the effects of salivary esterases, MMP inhibition and restorative materials on interfacial integrity. It was confirmed that interfacial integrity was compromised with time and was further deteriorated by simulated salivary esterases, as indicated by the greater depth of bacterial ingress and more bacterial biomass of biofilm along the interface. However, this process could be modulated by using different restorative materials and MMPs inhibition. This project elucidated the mechanistic interaction between oral bacteria and restorative materials and established a new, in vitro, and physiologically relevant model to assess the effect of material chemistry

Effect of Various Finishing Procedures on the Reflectivity (Shine) of Tooth Enamel - An In-vitro Study.

Science.gov (United States)

Patil, Harshal Ashok; Chitko, Shrikant Shrinivas; Kerudi, Veerendra Virupaxappa; Maheshwari, Amit Ratanlal; Patil, Neeraj Suresh; Tekale, Pawankumar Dnyandeo; Gore, Ketan Ashorao; Zope, Amit Ashok

2016-08-01

Reflectivity of an object is a good parameter for surface finish. As the patient evaluates finishing as a function of gloss/reflectivity/shine an attempt is made here to evaluate changes in surface finish with custom made reflectometer. The aim of the present study was to study the effect of various procedures during orthodontic treatment on the shine of enamel, using a custom made reflectometer. Sixty one extracted premolars were collected and each tooth was mounted on acrylic block. Reflectivity of the teeth was measured as compared to standard before any procedure. One tooth was kept as standard throughout the study. Sixty teeth were acid etched. Reflectivity was measured on custom made reflectometer and readings recorded. Same procedure was repeated after debonding. Then 60 samples were divided into three groups: Group 1 - Tungsten Carbide, Group 2 - Astropol, Group 3- Sof-Lex disc depending upon the finishing method after debonding and reflectivity was measured. The mean percentage of reflectivity after acid etching was 31.4%, debonding 45.5%, Tungsten carbide bur finishing (Group 1) was 58.3%, Astropol (Group 2) 72.8%, and Sof-Lex disc (Group 3) 84.4% as that to the standard. There was statistically very highly significant (p Group 2> Group 1. The primary goal was to restore the enamel to its original state after orthodontic treatment. The methods tested in this study could not restore the original enamel reflectivity.

Analysis of tooth tissues using Raman spectroscopy

International Nuclear Information System (INIS)

Timchenko, E.V.; Timchenko, P.E.; Kulabukhova, A.Yu.; Volova, L.T.; Rosenbaum, A.Yu.

2016-01-01

The results of experimental studies of healthy tooth tissue and tooth tissues during caries disease are presented. Features of Raman spectrum of tooth tissues during caries disease are obtained: the main changes are detected at wavenumbers 956 cm -1 .1069 cm -1 . corresponding to phosphates. and 1241 cm -1 . 1660 cm -1 . corresponding to collagen III and collagen I. respectively. Were introduced criteria allowing to detect caries and to identify weakening of tooth tissues. preceding the caries. The reliability of research results is confirmed by scanning electron microscopy. (paper)

Primary culprit for tooth loss!!

Directory of Open Access Journals (Sweden)

Sailavanya Nuvvula

2016-01-01

Full Text Available Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A questionnaire containing 10 items was distributed to the dental practitioners, which included age, gender, no of teeth indicated for extraction, the reason for extraction, and the periodontal parameters that are involved with the extracted tooth and were requested to complete the form on every extraction they were to undertake. the study form was collected at the end of the study period and data was subjected to statistical analysis. Results: A total of 502 patients were enrolled during the study period, and a total of 1055 teeth were extracted for several reasons. we found that 51.14%extractions are due to dental caries in case of 20-30years age groups, which is more when compared to tooth loss due to periodontal diseases in this age group. whereas in case of >40years of age group periodontal diseases account for 54.11%, and dental caries accounts for only 29.11%. Showing more teeth were lost due to periodontal disease. Conclusion: therefore we concluded that, caries is the dominant reason for extraction in patients with 20–30 years of age while periodontal disease accounts for the majority of tooth extraction in patients older than 40 years.

Profilometric analysis of two composite resins' surface repolished after tooth brush abrasion with three polishing systems.

Science.gov (United States)

Uppal, Mudit; Ganesh, Arathi; Balagopal, Suresh; Kaur, Gurleen

2013-07-01

To evaluate the effect of three polishing protocols that could be implemented at recall on the surface roughness of two direct esthetic restorative materials. Specimens (n = 40) measuring 8 mm (length) × 5 mm (width) × 4 mm (height) were fabricated in an acrylic mold using two light-cured resin-based materials (microfilled composite and microhybrid composite). After photopolymerization, all specimens were finished and polished with one of three polishing protocols (Enhance, One Gloss, and Sof-Lex polishing systems). The average surface roughness of each treated specimen was determined using 3D optical profilometer. Next all specimens were brushed 60,000 times with nylon bristles at 7200 rpm using crosshead brushing device with equal parts of toothpaste and water used as abrasive medium. The surface roughness of each specimen was measured after brushing followed by repolishing with one of three polishing protocols, and then, the final surface roughness values were determined. The data were analyzed using one-way and two-factor analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD). Significant difference (P < 0.05) in surface roughness was observed. Simulated brushing following initial polishing procedure significantly roughened the surface of restorative material (P < 0.05). Polishing protocols can be used to restore a smooth surface on esthetic restorative materials following simulated tooth brushing.

Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

LENUS (Irish Health Repository)

Harding, M A

2010-03-01

To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.

Using modified polyetheretherketone (PEEK) as an alternative material for endocrown restorations: A short-term clinical report.

Science.gov (United States)

Zoidis, Panagiotis; Bakiri, Eleonora; Polyzois, Gregory

2017-03-01

A modified polyetheretherketone (PEEK) framework material veneered with indirect light-polymerized composite resin was used as an alternative material for the fabrication of an endocrown restoration for an extensively damaged molar. The elastic modulus of the polyetheretherketone framework (4 GPa) veneered with indirect composite resin could dampen the occlusal forces protecting tooth structures better than ceramic materials. This is important in the restoration of extensively damaged molars with weak roots. Long-term clinical evidence is required before recommending the application as a substitute material. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Clinical attachment level gain and bone regeneration around a glass ionomer restoration on root surface wall of periodontal pocket

Science.gov (United States)

Biniraj, K. R.; Sagir, Mohammed; Sunil, M. M.; Janardhanan, Mahija

2012-01-01

A case describing perio-restorative management of an accidental trauma in the mid portion of root on an upper left canine tooth following an ostectomy surgery is presented here. The traumatized root area was undergoing fast resorption and a chronic periodontal abscess had developed in relation to the lesion. The article illustrates the clinical and radiographic photo series of a periodontal flap surgery done to gain access into a subgingival region for the placement of Glass ionomer restoration on the root and its periodic follow up. The clinical condition of the area suggests 8 mm clinical attachment gain over the restoration and the review radiographs at definite intervals up to 18 months revealed evidence of consistent bone regeneration around the restoration. The article also highlights the various other possibilities, where this restorative material can be effectively used in conjunction with periodontal surgical procedures. PMID:23162344

Marginal and Internal Gap of Handmade, Milled and 3D Printed Additive Manufactured Patterns for Pressed Lithium Disilicate Onlay Restorations.

Science.gov (United States)

Revilla-León, M; Olea-Vielba, M; Esteso-Saiz, A; Martínez-Klemm, I; Özcan, M

2018-03-01

On a pressed lithium disilicate restoration, the building up of a wax pattern of the future restoration is a necessary step on the fabrication process. Conventionally, a wax pattern can be produced by handmade or milled procedures; however, the development of additive manufacturing technologies allows a new fabrication method. The present study measured the marginal and internal gap of handmade, milled and additive manufactured patterns for an onlay restoration. A preparation of an onlay restoration was made on an extracted mandibular tooth. A definitive cast was fabricated from a conventional silicone impression of the prepared tooth. Three groups were established: handmade (HM), milled (ML) and additive manufactured (AM); 4 specimens per group were obtained. The marginal and internal gap of each pattern was measured on the extracted molar through a computed tomography test. Sixty measurements were done to measure the marginal gap and another 60 measurements were calculated to analyze the internal gap on each pattern on the prepared tooth. A total of 1.440 measurements were completed. Mann-Whitney and Turkey statistical tests were used for pairwise comparison. The mean of the marginal and internal gap was of 67.56 ± 6.08 μm and 80.62 ± 3.26 μm for the HM group, 85.28 ± 2.17 μm and 96 ± 1.97 μm for the ML group and 86.49 ± 1.74 μm and 91.86 ± 2.88 μm for the AM group, respectively. The HM group presented significantly lower marginal (p=0.029) and internal (p=0.029) gap compared to the ML and AM groups. There was no statistical significant difference (p=0.486) on the marginal gap between the ML and the AM groups, but the AM group, showed significantly (p=0.029) smaller internal gap than the ML group. All the groups presented less than 100 μm marginal and internal gap, which is a considered clinically acceptable. The three fabrication processes are viable option for manufacturing patterns for lithium disilicate onlay restorations, but the best marginal

Accelerated tooth eruption in children with diabetes mellitus.

Science.gov (United States)

Lal, Shantanu; Cheng, Bin; Kaplan, Selma; Softness, Barney; Greenberg, Ellen; Goland, Robin S; Lalla, Evanthia; Lamster, Ira B

2008-05-01

The objective of this study was to evaluate tooth eruption in 6- to 14-year-old children with diabetes mellitus. Tooth eruption status was assessed for 270 children with diabetes and 320 control children without diabetes. Data on important diabetes-related variables were collected. Analyses were performed using logistic regression models. Children with diabetes exhibited accelerated tooth eruption in the late mixed dentition period (10-14 years of age) compared to healthy children. For both case patients and control subjects the odds of a tooth being in an advanced eruptive stage were significantly higher among girls than boys. There was also a trend associating gingival inflammation with expedited tooth eruption in both groups. No association was found between the odds of a tooth being in an advanced stage of eruption and hemoglobin A(1c) or duration of diabetes. Patients with higher body mass index percentile demonstrated statistically higher odds for accelerated tooth eruption, but the association was not clinically significant. Children with diabetes exhibit accelerated tooth eruption. Future studies need to ascertain the role of such aberrations in dental development and complications such as malocclusion, impaired oral hygiene, and periodontal disease. The standards of care for children with diabetes should include screening and referral programs aimed at oral health promotion and disease prevention.

Immediate placement and restoration of dental implants in the esthetic region: clinical case series.

Science.gov (United States)

Khzam, Nabil; Mattheos, Nikos; Roberts, David; Bruce, William L; Ivanovski, Saso

2014-01-01

The objective of this study was to assess the hard and soft tissue changes following immediate placement and provisional restoration of single-tooth implants in the aesthetic zone. Thirteen patients with immediately placed and restored implants were included in this study. All participating patients underwent the same treatment strategy that involved removal of the failed tooth, flapless surgery, immediate implant placement, and connection of a screw-retained provisional restoration. Three months following implant placement, the temporary crowns were replaced by the definitive restorations. Implant survival rates, and hard and soft tissue changes were measured using periapical X-rays and photographs. The range of the observation period was between 12 and 37 months with a mean period of 23.2 ± 7.6 months. At the time of follow-up, all implants were present with no complications. Radiographic evaluation revealed a mean mesial bone gain of 1.20 ± 1.01 mm and a mean distal bone gain of 0.80 ± 1.14 mm, which reached statistical significance. The mean mid-buccal recession was 0.20 ± 0.78 mm, whereas the mesial and distal papillae height loss was 0.50 ± 1.26 mm and 0.30 ± 0.82 mm, respectively. The changes in the soft tissues did not reach statistical significance. Notwithstanding the limitation of a small sample size, this study shows that immediate implant placement and provisional restoration in the maxillary aesthetic zone can result in favorable treatment outcomes with regards to soft and hard tissues changes over a follow-up period of 23.2 ± 7.6 months. Most clinical trials investigating immediate implant placement and immediate restoration in the maxillary anterior zone have focused on implant survival and implant success, with particular emphasis on radiographically assessed hard tissues changes. However, this study assesses the soft tissue changes associated with this procedure, which is an important area of study

Marine Ecosystem Restoration in Changing European Seas

DEFF Research Database (Denmark)

Ounanian, Kristen; Delaney, Alyne; Carballo Cárdenas, Eira

2017-01-01

and using different narratives of marine restoration, and being confronted with different forms of uncertainties. The paper’s overall contribution is the synthesis of these seemingly disparate components (narratives of restoration, uncertainty in decision making, and governance arrangements) to evaluate...... the impact of existing (maritime and environmental) policies, the governance setting, definitions of restoration and uncertainties on the effectiveness of marine restoration projects. Such a synthesis is a necessary move toward a systematic evaluation of ways to govern and formally institutionalize marine...

Evaluation of the surface structure of composite restorations in light of own pilot research

Directory of Open Access Journals (Sweden)

Chalas Renata

2016-09-01

Full Text Available Research on the dental restorative materials employed in remedying dental cavities has been conducted on many levels and areas, both with application of clinical and laboratory methods. One of the elements that determines whether the restoration may be degraded is the condition of its surface. The aim of the study was to assess the texture surface of composite restorations using a non-contact method of teeth models scanning. In this work, ten medium size cavities on the occlusal surfaces of molars in adult patients were prepared and restored with resin composite. Before undertaking the procedure and after the finishing and polishing of the restorations, impressions were taken and sent into the laboratory so as to prepare plaster casts. Every cast was then scanned utilizing the non-contact 3D surface measurement instrument so as to assess the texture surface of the restoration. The resulting three dimensional analyses of post-restoration models showed the correct marginal adaptation of resin composite dental material to the hard tooth structures and its smooth filling occlusal surface. Additional comparison of scans done before and after restoring the cavities allowed the calculating of differences in volume, mean and maximum heights. The applied method of analysis is thought to be helpful in the detailed evaluation of restoration dental material texture. Moreover, the enabled possibility of continuous observation is expedient for assessing the usefulness of the method in standard dental practice.

In vitro comparison of fracture load of implant-supported, zirconia-based, porcelain- and composite-layered restorations after artificial aging.

Science.gov (United States)

Komine, Futoshi; Taguchi, Kohei; Fushiki, Ryosuke; Kamio, Shingo; Iwasaki, Taro; Matsumura, Hideo

2014-01-01

This study evaluated fracture load of single-tooth, implant-supported, zirconia-based, porcelain- and indirect composite-layered restorations after artificial aging. Forty-four zirconia-based molar restorations were fabricated on implant abutments and divided into four groups, namely, zirconia-based all-ceramic restorations (ZAC group) and three types of zirconia-based composite-layered restorations (ZIC-P, ZIC-E, and ZIC groups). Before layering an indirect composite material, the zirconia copings in the ZIC-P and ZIC-E groups were primed with Clearfil Photo Bond and Estenia Opaque Primer, respectively. All restorations were cemented on the abutments with glass-ionomer cement and then subjected to thermal cycling and cyclic loading. All specimens survived thermal cycling and cyclic loading. The fracture load of the ZIC-P group (2.72 kN) was not significantly different from that of the ZAC group (3.05 kN). The fracture load of the zirconia-based composite-layered restoration primed with Clearfil Photo Bond (ZIC-P) was comparable to that of the zirconia-based all-ceramic restoration (ZAC) after artificial aging.

Synthetic tooth enamel: SEM characterization of a fluoride hydroxyapatite coating for dentistry applications

Directory of Open Access Journals (Sweden)

Marise Oliveira

2007-06-01

Full Text Available An alternative to etching enamel for retention of an adhesive is to grow crystals on the enamel surface. The potential advantages of crystal growth include easy procedure and less damage to the enamel. These crystals retain the adhesive or are the actual dental restoration. In this work, a paste of synthetic enamel was used to grow crystals of fluoride hydroxyapatite (F-HA onto the human tooth surface. This technique can be used for several dentistry applications like enamel whitening, strengthening and restoration of early carie lesions. The low cost of reagents and simplicity of the technique along with the biocompatibility of the paste render possible the utilization on the market. The samples were prepared through the application of the paste by the incremental technique. The results obtained by scanning electron microscope (SEM/EDX have indicated the deposition of a homogeneous layer of calcium phosphate that was grown onto the enamel substrate. The average thickness of the deposited film was in the range of 50-100 µm and with a similar density from the natural enamel observed by radiographic images.

Landscaping Considerations for Urban Stream Restoration Projects

National Research Council Canada - National Science Library

Bailey, Pam

2004-01-01

... after restoration and its functionality for public use. The landscaping component of such stream and riparian restoration projects must be emphasized given its importance of visual success and public perception. The purpose of this technical note is to address landscaping considerations associated with urban stream and riparian restoration projects, and provide ideas to managers for enhancing the visual appeal and aesthetic qualities of urban projects.

Towards a decision support system for stream restoration in the Netherlands: an overview of restoration projects and future needs

NARCIS (Netherlands)

Verdonschot, P.F.M.; Nijboer, R.C.

2002-01-01

Stream restoration is one of the answers to the lowland stream deterioration. For making proper choices in stream restoration, one firstly needs to understand the complex spatial and temporal interactions between physical, chemical and biological components in the stream ecosystem. Several

Tooth loss prevalence among cardiac males and females

International Nuclear Information System (INIS)

Bokhari, S.A.H.; Khan, A.A.; Butt, A.K.

2007-01-01

Objective of study was to observe differences of tooth loss prevalence in males and females with Cardiac diseases Poor oral health, tooth loss and periodontal diseases have been reported to be associated with coronary heart diseases. Studies report gender differences in prevalence of cardiac diseases and tooth loss. This paper presents gender differences of tooth loss in cardiac patients of a cardiac hospital of Lahore, Pakistan. Methodology: Age matched Cardiac males and females attending OPD of the Punjab Institute of Cardiology (PIC), Lahore were included in the study. Personal and health-related information were questioned and noted. Oral examination was performed for recording of missing teeth. 1200 CHD study subjects with age-range of 30 to 80 years were enrolled for study. 1045 age matched, 766 (73.30%) males and 279 (26.70%) females were examined for tooth loss. 852 (81.53%) genders had at least one tooth missing. 599 (78.19) males and 253 (90.68%) females were observed with mean tooth loss of 7.5 (SD 8.720) and 11.15 (SD 10.375)respectively statistical association among them was also significant (P= 0.000) with OR of 2.339. More subjects (76.29%) showed a loss of 1-15 teeth that I was also significant among males and females. Tooth loss was significant in age groups of 41-50 years (P=0.001) and 51-60 years (P=0.000) Gender differences of tooth loss prevalence among CHD Subjects were significant with more risk for males as compared to females. (author)

Functional constraints on tooth morphology in carnivorous mammals

Directory of Open Access Journals (Sweden)

Smits Peter D

2012-08-01

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

Heritable patterns of tooth decay in the permanent dentition: principal components and factor analyses.

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Shaffer, John R; Feingold, Eleanor; Wang, Xiaojing; Tcuenco, Karen T; Weeks, Daniel E; DeSensi, Rebecca S; Polk, Deborah E; Wendell, Steve; Weyant, Robert J; Crout, Richard; McNeil, Daniel W; Marazita, Mary L

2012-03-09

Dental caries is the result of a complex interplay among environmental, behavioral, and genetic factors, with distinct patterns of decay likely due to specific etiologies. Therefore, global measures of decay, such as the DMFS index, may not be optimal for identifying risk factors that manifest as specific decay patterns, especially if the risk factors such as genetic susceptibility loci have small individual effects. We used two methods to extract patterns of decay from surface-level caries data in order to generate novel phenotypes with which to explore the genetic regulation of caries. The 128 tooth surfaces of the permanent dentition were scored as carious or not by intra-oral examination for 1,068 participants aged 18 to 75 years from 664 biological families. Principal components analysis (PCA) and factor analysis (FA), two methods of identifying underlying patterns without a priori surface classifications, were applied to our data. The three strongest caries patterns identified by PCA recaptured variation represented by DMFS index (correlation, r = 0.97), pit and fissure surface caries (r = 0.95), and smooth surface caries (r = 0.89). However, together, these three patterns explained only 37% of the variability in the data, indicating that a priori caries measures are insufficient for fully quantifying caries variation. In comparison, the first pattern identified by FA was strongly correlated with pit and fissure surface caries (r = 0.81), but other identified patterns, including a second pattern representing caries of the maxillary incisors, were not representative of any previously defined caries indices. Some patterns identified by PCA and FA were heritable (h(2) = 30-65%, p = 0.043-0.006), whereas other patterns were not, indicating both genetic and non-genetic etiologies of individual decay patterns. This study demonstrates the use of decay patterns as novel phenotypes to assist in understanding the multifactorial nature of dental caries.

Er:YAG Laser and Fractured Incisor Restorations: An In Vitro Study

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C. Fornaini

2012-01-01

Full Text Available Introduction. The aim of this study was to analyse the effects of an Er:YAG laser on enamel and dentine in cases of dental restorations involving fractured teeth, utilizing the dental fragment. Materials and Methods. Seventy-two freshly extracted bovine incisors were fractured at the coronal level by using a hammer applied with a standardized method, and the fragment was reattached by using three different methods: Er:YAG laser, orthophosphoric acid, and laser plus acid. The different groups were evaluated by a test realized with the dynamometer to know the force required to successfully detach the reattached fragment and by a microinfiltration test by using a 0.5% methylene blue solution followed by the optic microscope observation. Results. The compression test showed only a slight difference between the three groups, without any statistical significance. The infiltration test used to evaluate the marginal seal between the fracture fragment and the tooth demonstrated that etching with Er:YAG laser alone or in combination with orthophosphoric acid gives better results than orthophosphoric acid alone, with a highly significant statistical result. Discussion. Reattaching a tooth fragment represents a clinically proven methodology, in terms of achieving resistance to detachment, and the aim of this work was to demonstrate the advantages of Er:YAG laser on this procedure. Conclusion. This “in vitro” study confirms that Er:YAG laser can be employed in dental traumatology to restore frontal teeth after coronal fracture.

Use of ultrasound Doppler to determine tooth vitality in a discolored tooth after traumatic injury: its prospects and limitations

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Yong-Wook Cho

2014-02-01

Full Text Available When a tooth shows discoloration and does not respond to the cold test or electric pulp test (EPT after a traumatic injury, its diagnosis can be even more difficult due to the lack of proper diagnostic methods to evaluate its vitality. In these case reports, we hope to demonstrate that ultrasound Doppler might be successfully used to evaluate the vitality of the tooth after trauma, and help reduce unnecessary endodontic treatments. In all three of the present cases, the teeth were discolored after traumatic injuries and showed negative responses to the cold test and EPT. However, they showed distinctive vital reactions in the ultrasound Doppler test during the whole observation period. In the first case, the tooth color returned to normal, and the tooth showed a positive response to the cold test and EPT at 10 wk after the injury. In the second case, the tooth color had returned to its normal shade at 10 wk after the traumatic injury but remained insensitive to the cold test and EPT. In the third case, the discoloration was successfully treated with vital tooth bleaching.

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

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Francesco Guido Mangano

2014-01-01

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

Clinical performance of direct versus indirect composite restorations in posterior teeth: A systematic review.

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Azeem, Rubeena Abdul; Sureshbabu, Nivedhitha Malli

2018-01-01

Composite resin, serves as esthetic alternative to amalgam and cast restorations. Posterior teeth can be restored using direct or indirect composite restorations. The selection between direct and indirect technique is a clinically challenging decision-making process. Most important influencing factor is the amount of remaining tooth substance. The aim of this systematic review was to compare the clinical performance of direct versus indirect composite restorations in posterior teeth. The databases searched included PubMed CENTRAL (until July 2015), Medline, and Cochrane Database of Systematic Reviews. The bibliographies of clinical studies and reviews identified in the electronic search were analyzed to identify studies which were published outside the electronically searched journals. The primary outcome measure was evaluation of the survival of direct and indirect composite restorations in posterior teeth. This review included thirteen studies in which clinical performance of various types of direct and indirect composite restorations in posterior teeth were compared. Out of the thirteen studies which were included seven studies had a high risk of bias and five studies had a moderate risk of bias. One study having a low risk of bias, concluded that there was no significant difference between direct and indirect technique. However, the available evidence revealed inconclusive results. Further research should focus on randomized controlled trials with long term follow-up to give concrete evidence on the clinical performce of direct and indirect composite restorations.

Autogenous Transplantation for Replacing a Hopeless Tooth.

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Zakershahrak, Mehrsa; Moshari, Amirabbas; Vatanpour, Mehdi; Khalilak, Zohreh; Jalali Ara, Afsoon

2017-01-01

Autogenous tooth transplantation (ATT) is a simple and reasonable choice for replacing the missing teeth when a proper donor tooth is available. This report presents a case of successful ATT of a maxillary right third molar for replacement of mandibular right second molar with a concomitant endodontic-periodontal disease. The mandibular second molar was believed to be hopeless due to a severe damage to coronal tooth structure, inappropriate root canal treatment and apical radiolucency. After extraction of mandibular second molar and maxillary third molar (the donor), the tooth was re-implanted into the extracted socket of second molar site. Root canal therapy was then performed. After 3 years, clinical and radiographic examinations revealed satisfying results, with no signs and symptoms. The patient is asymptomatic and the transplanted tooth is still functional with no signs of marginal periodontal pathosis. Radiographies showed bone regeneration in the site of previous extensive periapical lesion, normal periodontal ligament with no signs of root resorption.

21 CFR 872.3580 - Preformed gold denture tooth.

Science.gov (United States)

2010-04-01

... tooth in a fixed or removable partial denture. (b) Classification. Class I (general controls). The... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Preformed gold denture tooth. 872.3580 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a...

Mechanical site preparation for forest restoration

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Magnus Lof; Daniel C. Dey; Rafael M. Navarro; Douglass F. Jacobs

2012-01-01

Forest restoration projects have become increasingly common around the world and planting trees is almost always a key component. Low seedling survival and growth may result in restoration failures and various mechanical site preparation techniques for treatment of soils and vegetation are important tools used to help counteract this. In this article, we synthesize the...

The effect of fiber dowel heights in resin composite cores on restoration failures of endodontically treated teeth.

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Mekayarajjananonth, Trakol; Chitcharus, Nattinee; Winkler, Sheldon; Bogert, Meredith C

2009-01-01

In vitro and in vivo testing suggest that fiber posts may reduce the incidence of root fractures of endodontically treated teeth. The purpose of this in vitro study was to compare the effect of fiber post height in resin composite cores on the fracture resistance of endodontically treated teeth. Forty maxillary central incisors were randomly divided into 2 control groups (Groups 1 and 2) of 5 teeth each, and 3 experimental groups (Groups 3, 4, and 5) of 10 teeth each. The teeth in Group 1 had their opening restored with composite resin, the teeth in Group 2 were restored with quartz fiber posts without resin composite cores, and the teeth in Groups 3, 4, and 5 were restored with quartz fiber posts of 2, 4, and 6 mm high, respectively, in 6-mm resin composite cores. Ceramic crowns were fabricated for the specimens. Specimens were positioned in a mounting device and aligned at a 130-degree angle to the long axis of each tooth. A universal testing machine was used to apply constant load at a crosshead speed of 0.5 mm/min until failure occurred. The highest fracture load and mode of failure of each specimen was recorded. The highest fracture resistance force was observed in Group 2 (290.38 +/- 48.45 N) and decreased, respectively, in Group 1 (238.98 +/-26.26 N), Group 5 (228.35 +/-58.79 N), Group 4 (221.43 +/-38.74 N), and Group 3 (199.05 +/-58.00 N). According to one-way analysis of variance (ANOVA) and Duncan's test (P teeth should be restored with the longest possible post height while preserving maximum tooth structure.

Marginal microleakage of class V composite restorations before and after AFP gel application

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Davari Abdolrahim

2015-01-01

Full Text Available   Background and Aims: The most effective preventing tooth decay method is fluoride compounds applications. Some studies suggested that APF gels caused changes on the superficial physical properties of composite. Therefore, the purpose of this study was to evaluate the marginal microleakage of class V composite restorations before and after AFP gel application.   Materials and Methods: The class V cavities in buccal surfaces of 45 molar teeth were made in such a way that occlusal margin was placed in enamel and cervical margin in cement. In group 1, at first fluoride-therapy and then cavity preparation and restoration by composite resin was done. In group 2, at first the class V cavities were prepared and restored, then fluoride-therapy was carried out. In group 3, cavities were prepared and restored with no fluoride-therapy. The dye penetration rate in occlusal and cervical margins was examined by stereomicroscope. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney test.   Results: There was no statistically significant difference between groups ( P=0.975.   Conclusion: Fluoride-therapy using AFP gel before and after class V composite restorations, had no significant effect on the microleakage of dentin and enamel margins.

Intrapulpal Temperature Rise During Light Activation of Restorative Composites in a Primary Molar.

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Vinall, Craig V; Garcia-Silva, Tales C; Lou, Jennifer S B; Wells, Martha H; Tantbirojn, Daranee; Versluis, Antheunis

2017-05-15

To investigate intrapulpal temperature rise in a primary molar during light activation of a composite restoration to determine if clinically significant pulpal temperatures (greater than 5.5 degrees Celsius) were reached. Restorative composites (EsthetX HD, Filtek Supreme Ultra, Filtek Bulk Fill) were placed into a primary molar with occlusal preparation (1.5 mm depth; remaining pulpal floor thickness one mm). The pulp was extirpated through a root access to place a thermocouple against the pulpal roof. Temperature changes were recorded during composite restoration light polymerization with three curing lights (one quartz-tungsten-halogen, two LEDs). Sample size was 10. Samples received additional irradiation to assure complete polymerization, followed by a third irradiation for calculating the exothermic heat contribution (subtracting third irradiation temperatures from first irradiation temperatures). Cured restorations were removed after each test, and the tooth was reused. Results were analyzed with Kruskal-Wallis (α =0.05). Type of curing light and composite material affected the intrapulpal temperature rise, which was up to five degrees Celsius for one combination of LED-composite. Clinicians should be aware of the potential for clinically significant intrapulpal temperature rises when light-activating composite restorations in a primary molar with a moderately deep cavity.

An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

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Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

2014-03-01

Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

ART restorations and sealants placed in Chinese school children--results after three years.

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Holmgren, C J; Lo, E C; Hu, D; Wan, H

2000-08-01

These were to assess whether ART restorations and sealants could be provided to children in a school environment in China, to assess patient acceptability of the ART approach, and to evaluate on a longitudinal basis the treatments performed. This study was conducted in Deyang, Sichuan Province, in western China. A total of 294 ART restorations were placed in 197 children and 191 fissure sealants were placed in 140 children by five middle-level dentists in four secondary schools. Standard instruments and procedures for ART were used. The restorative material used was a high-strength glass-ionomer (Ketac-Molar, ESPE). The treatments were evaluated annually after placement by the same examiner who had not been involved in the placement of the restorations nor sealants using explorers and mouth-mirrors. At the 3-year examination an independent external examiner evaluated the restorations using USPHS criteria. Most of the children did not report discomfort during treatment and 92% were willing to receive ART restorations again. The cumulative 1-year and 3-year survival rates of small Class I restorations were 99% and 92% respectively. The corresponding figures for large Class I restorations were 90% and 77%. After 3 years, 72% of the sealants were either partially or completely retained. Only 2% of the sealed teeth developed fissure caries and these involved teeth where the sealants had been lost. Similar success rates were found using USPHS criteria. The ART approach for preventing and treating tooth decay in Chinese school children was shown to be appropriate, effective and acceptable. The 3-year survival rates of the restorations were high but were related to the size and type of the restoration.

Flexible, wireless, inductively coupled surface coil resonator for EPR tooth dosimetry

International Nuclear Information System (INIS)

Schreiber, Wilson; Petryakov, Sergey V.; Kmiec, Maciej M.; Feldman, Matthew A.; Wood, Victoria A.; Boyle, Holly K.; Flood, Ann Barry; Williams, Benjamin B.; Swartz, Harold M.; Meaney, Paul M.

2016-01-01

Managing radiation injuries following a catastrophic event where large numbers of people may have been exposed to life-threatening doses of ionizing radiation relies on the availability of biodosimetry to assess whether individuals need to be triaged for care. Electron Paramagnetic Resonance (EPR) tooth dosimetry is a viable method to accurately estimate the amount of ionizing radiation to which an individual has been exposed. In the intended measurement conditions and scenario, it is essential that the measurement process be fast, straightforward and provides meaningful and accurate dose estimations for individuals in the expected measurement conditions. The sensing component of a conventional L-band EPR spectrometer used for tooth dosimetry typically consists of a surface coil resonator that is rigidly, physically attached to the coupler. This design can result in cumbersome operation, limitations in teeth geometries that may be measured and hinder the overall utility of the dosimeter. A novel surface coil resonator has been developed for the currently existing L-band (1.15 GHz) EPR tooth dosimeter for the intended use as a point of care device by minimally trained operators. This resonator development provides further utility to the dosimeter, and increases the usability of the dosimeter by non-expert operators in the intended use scenario. (authors)

Resetting translational homeostasis restores myelination in Charcot-Marie-Tooth disease type 1B mice.

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D'Antonio, Maurizio; Musner, Nicolò; Scapin, Cristina; Ungaro, Daniela; Del Carro, Ubaldo; Ron, David; Feltri, M Laura; Wrabetz, Lawrence

2013-04-08

P0 glycoprotein is an abundant product of terminal differentiation in myelinating Schwann cells. The mutant P0S63del causes Charcot-Marie-Tooth 1B neuropathy in humans, and a very similar demyelinating neuropathy in transgenic mice. P0S63del is retained in the endoplasmic reticulum of Schwann cells, where it promotes unfolded protein stress and elicits an unfolded protein response (UPR) associated with translational attenuation. Ablation of Chop, a UPR mediator, from S63del mice completely rescues their motor deficit and reduces active demyelination by half. Here, we show that Gadd34 is a detrimental effector of CHOP that reactivates translation too aggressively in myelinating Schwann cells. Genetic or pharmacological limitation of Gadd34 function moderates translational reactivation, improves myelination in S63del nerves, and reduces accumulation of P0S63del in the ER. Resetting translational homeostasis may provide a therapeutic strategy in tissues impaired by misfolded proteins that are synthesized during terminal differentiation.

21 CFR 872.5525 - Preformed tooth positioner.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that is an impression of a perfected bite...

Remineralising efficacy of tooth mousse plus (ACP CCPF) on radiated tooth

International Nuclear Information System (INIS)

Priya; Hegde, Mithra N.; Hegde, Nidarsh D.; Suchetha Kumari, N.; Sanjeev, Ganesh

2016-01-01

Dental complication is the common problem faced all over the world. Subjects with poor oral hygiene and patients undergoing radiotherapy for oral cancers are developing signs of decalcification of enamel, lesions and Caries. A well designed treatment is necessary to safeguard the tooth enamel surface before and after radiation, only then the caries on the enamel surface can be arrested by re-hardening it and ultimately converting them to the normal healthy condition. To determine the Annealing effect of radiated tooth by testing maximum micro hardness of the teeth before and after 30 days of radiation by the application of Remineralising agents. In our study, we collected 30 intact caries free human molar teeth and were sectioned mesio-distally

Variables affecting orthodontic tooth movement with clear aligners.

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Chisari, Justin R; McGorray, Susan P; Nair, Madhu; Wheeler, Timothy T

2014-04-01

In this study, we examined the impacts of age, sex, root length, bone levels, and bone quality on orthodontic tooth movement. Clear aligners were programmed to move 1 central incisor 1 mm over the course of 8 weeks. Thirty subjects, ages 19 to 64, were enrolled, and measurements were made on digital models (percentage of tooth movement goal achieved). Morphometric features and bone quality were assessed with cone-beam computed tomography. Data from this study were combined with data from 2 similar studies to increase the power for some analyses. The mean percentage of tooth movement goal achieved was 57% overall. Linear regression modeling indicated a cubic relationship between age and tooth movement, with a decreasing rate of movement from ages 18 to 35 years, a slightly increasing rate from ages 35 to 50, and a decreasing rate from ages 50 to 70. The final decreasing trend was not apparent for women. As would be expected, the correlation was significant between the percentage of the goal achieved and the cone-beam computed tomography superimposed linear measures of tooth movement. A significant negative correlation was found between tooth movement and the measurement apex to the center of rotation, but bone quality, as measured by fractal dimension, was not correlated with movement. The relationship between age and tooth movement is complex and might differ for male and female patients. Limited correlations with cone-beam computed tomography morphology and rate of tooth movement were detected. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Tooth resorption in cats: contribution of vitamin D and inflammation

NARCIS (Netherlands)

Vrieling, H.E.

2010-01-01

Tooth resorption in cats Tooth resorption affecting several teeth is a painful disease with a prevalence of up to 75% in household cats and is often accompanied by periodontitis. Tooth resorption is caused by an increased number and activity of tooth-resorbing odontoclasts, cells that share

Tooth Fracture Detection in Spiral Bevel Gears System by Harmonic Response Based on Finite Element Method

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Yuan Chen

2017-01-01

Full Text Available Spiral bevel gears occupy several advantages such as high contact ratio, strong carrying capacity, and smooth operation, which become one of the most widely used components in high-speed stage of the aeronautical transmission system. Its dynamic characteristics are addressed by many scholars. However, spiral bevel gears, especially tooth fracture occurrence and monitoring, are not to be investigated, according to the limited published issues. Therefore, this paper establishes a three-dimensional model and finite element model of the Gleason spiral bevel gear pair. The model considers the effect of tooth root fracture on the system due to fatigue. Finite element method is used to compute the mesh generation, set the boundary condition, and carry out the dynamic load. The harmonic response spectra of the base under tooth fracture are calculated and the influence of main parameters on monitoring failure is investigated as well. The results show that the change of torque affects insignificantly the determination of whether or not the system has tooth fracture. The intermediate frequency interval (200 Hz–1000 Hz is the best interval to judge tooth fracture occurrence. The best fault test region is located in the working area where the system is going through meshing. The simulation calculation provides a theoretical reference for spiral bevel gear system test and fault diagnosis.

Tooth fractures in canine clinical practice

International Nuclear Information System (INIS)

Capik, I.; Ledecky, V.; Sevcik, A.

2001-01-01

Tooth fractures constitute a considerable fraction of all tooth diseases. Out of the 5,370 dogs treated during four years, 492 were presented with dental problems and 28.3 % of the latter were treated for tooth fractures. Canines were the most frequently affected teeth (38.8 %), followed by premolars (33.1 %), incisors (25.9 %), and molars (2.2 %), 55.4 % of the patients with canine and incisor fractures being large breed dogs. Fractures of premolars (mostly of 108, 208) were divided evenly irrespective of breed or body size. Nonsurgical endodontic treatment yielded good therapeutic results in most cases, but repeated treatment was necessary in some patients

Ceramic onlay for endodontically treated mandibular molar

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Roopadevi Garlapati

2014-01-01

Full Text Available Restoration of endodontically treated teeth is important for the success of endodontic treatment. In full coverage restorations, maximum amount of tooth structure is compromised, so as to conserve the amount of tooth structure partial coverage restorations, can be preferred. This case report is on fabrication of a conservative tooth colored restoration for an endodontically treated posterior tooth. A 22-year-old male patient presented with pain in the mandibular left first molar. After endodontic treatment, composite material was used as postendodontic restoration. The tooth was then prepared to receive a ceramic onlay and bonded with self-adhesive universal resin cement. Ceramic onlay restoration was periodically examined up to 2 years.

Science in Action: Aesthetic Considerations for Stream Restoration

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Aesthetics are an integral component of the social and economic benefits of stream restoration and should be considered in restoration projects for sustainable management. According to Bernhardt et al. (2005), aesthetics is one of the frequently listed goals for stream restoratio...

Fluoride uptake from restorative dental materials by human enamel

International Nuclear Information System (INIS)

Forsten, L.; Rytoemaa, I.; Anttila, A.; Keinonen, J.

1976-01-01

The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth enamel and whether prior etching of the enamel causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials ; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the 19 F (p, αγ) 16 O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior enamel was 226 parts 10 6 . All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel. (author)

Restoration planning to guide Aichi targets in a megadiverse country.

Science.gov (United States)

Tobón, Wolke; Urquiza-Haas, Tania; Koleff, Patricia; Schröter, Matthias; Ortega-Álvarez, Rubén; Campo, Julio; Lindig-Cisneros, Roberto; Sarukhán, José; Bonn, Aletta

2017-10-01

Ecological restoration has become an important strategy to conserve biodiversity and ecosystems services. To restore 15% of degraded ecosystems as stipulated by the Convention on Biological Diversity Aichi target 15, we developed a prioritization framework to identify potential priority sites for restoration in Mexico, a megadiverse country. We used the most current biological and environmental data on Mexico to assess areas of biological importance and restoration feasibility at national scale and engaged stakeholders and experts throughout the process. We integrated 8 criteria into 2 components (i.e., biological importance and restoration feasibility) in a spatial multicriteria analysis and generated 11 scenarios to test the effect of assigning different component weights. The priority restoration sites were distributed across all terrestrial ecosystems of Mexico; 64.1% were in degraded natural vegetation and 6% were in protected areas. Our results provide a spatial guide to where restoration could enhance the persistence of species of conservation concern and vulnerable ecosystems while maximizing the likelihood of restoration success. Such spatial prioritization is a first step in informing policy makers and restoration planners where to focus local and large-scale restoration efforts, which should additionally incorporate social and monetary cost-benefit considerations. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Tooth cusp sharpness as a dietary correlate in great apes.

Science.gov (United States)

Berthaume, Michael A

2014-02-01

Mammalian molars have undergone heavy scrutiny to determine correlates between morphology and diet. Here, the relationship between one aspect of occlusal morphology, tooth cusp radius of curvature (RoC), and two broad dietary categories, folivory and frugivory, is analyzed in apes. The author hypothesizes that there is a relationship between tooth cusp RoC and diet, and that folivores have sharper teeth than frugivores, and further test the correlation between tooth cusp RoC and tooth cusp size. Eight measures of tooth cusp RoC (two RoCs per cusp) were taken from 53 M(2) s from four species and subspecies of frugivorous apes (Pongo pygmaeus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, and Gorilla gorilla gorilla) and two subspecies of folivorous apes (Gorilla beringei beringei, and Gorilla beringei graueri). Phylogenetically corrected ANOVAs were run on the full dataset and several subsets of the full dataset, revealing that, when buccolingual RoCs are taken into account, tooth cusp RoCs can successfully differentiate folivores and frugivores. PCAs revealed that folivores consistently had duller teeth than frugivores. In addition, a weak, statistically significant positive correlation exists between tooth cusp size and tooth cusp RoC. The author hypothesizes differences in tooth cusp RoC are correlated with wear rates, where, per vertical unit of wear, duller cusps will have a longer length of exposed enamel ridge than sharper cusps. More data need to be gathered to determine if the correlation between tooth cusp RoC and tooth cusp size holds true when small primates are considered. Copyright © 2013 Wiley Periodicals, Inc.

Impact of Atraumatic Restorative Treatment (ART) on the treatment profile in pilot government dental clinics in Tanzania.

Science.gov (United States)

Kikwilu, Emil Namakuka; Frencken, Jo; Mulder, Jan

2009-06-08

The predominant mode of treatment in government dental clinics in Tanzania has been tooth extraction because the economy could not support the conventional restorative care which depends on expensive equipment, electricity and piped water systems. Atraumatic Restorative Treatment (ART) was perceived as a suitable alternative. A 3.5-year study was designed to document the changes in the treatment profiles ascribed to the systematic introduction of ART in pilot government dental clinics. Dental practitioners who were working in 13 government dental clinics underwent a 7-day ART training. Treatment record data on teeth extracted and teeth restored by the conventional and ART approaches were collected from these clinics for the three study periods. The mean percentage of ART restorations to total treatment, ART restorations to total restorations, and total restorations to total treatments rendered were computed. Differences between variables were determined by ANOVA, t-test and Chi-square. The mean percentage of ART restorations to total treatment rendered was 0.4 (SE = 0.5) and 11.9 (SE = 1.1) during the baseline and second follow-up period respectively (ANOVA mixed model; P ART restorations to total restorations rendered at baseline and 2nd follow-up period was 8.4% and 88.9% respectively (ANOVA mixed model; P ART restorations, 96.6% willing to receive ART restoration again in future, and 94.9% willing to recommend ART treatment to their close relatives. ART introduction in pilot government dental clinics raised the number of teeth saved by restorative care. Countrywide introduction of the ART approach in Tanzania is recommended.

Life of a Tooth: A Visual Timeline

Medline Plus

Full Text Available ... Dentist Your Family's Oral Health About the AGD Dental care and oral health information you need from ... Menstrual Calendar for Tooth Extraction Learn what those dental words mean. The Life of a Tooth Home | ...

Is gingival recession a consequence of an orthodontic tooth size and/or tooth position discrepancy? "A paradigm shift".

Science.gov (United States)

Richman, Colin

2011-01-01

Gingival recession (GR) is a commonly observed dental lesion. The underlying etiology has not been clearly identified, although several theories have been suggested. Tooth crowding or tooth malalignment is also frequently observed, with both conditions appearing to be more prevalent in developed countries with heterogeneous populations. A total of 25 consecutively treated patients representing 72 teeth and demonstrating facial clinical GR of > 3 mm were examined clinically, photographically, and with 3-dimensional radiology using conebeam computed tomography. All examined teeth presented with normal interproximal probing depths and attachment levels (teeth demonstrating > 3 mm of GR presented with significantly prominent facial tooth contours and associated alveolar bone dehiscences. Most involved teeth presented with their root structures extending beyond the facial alveolar bony housing (fenestrations). This represents a discrepancy between tooth size and alveolar bone dimensions in the buccolingual, axial, and sagittal orientation. Fewer involved teeth were malpositioned toward the buccal aspect. Both conditions were associated with facial alveolar bone dehiscences and associated GR. This study suggests tooth volume and/or tooth position within the alveolar bony housing strongly correlate with GR. All nonperiodontitis-involved teeth with GR were associated with either wider teeth or facially aligned teeth. However, it is emphasized that all facially aligned teeth, or "larger" teeth, do not necessarily present with GR. Based on these findings, the radiographic-supporting bone index is proposed. This index should facilitate appropriate evaluation of the alveolar bone supporting the mucogingival complex, both on the facial and lingual aspect of teeth. Further investigations are needed to support these preliminary data.

Gastroesophageal Reflux Disease and Tooth Erosion

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Sarbin Ranjitkar

2012-01-01

Full Text Available 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.

Tooth positioners and their effects on treatment outcome.

Science.gov (United States)

Pravindevaprasad, A; Therese, Beena Agnes

2013-07-01

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.

One year Survival Rate of Ketac Molar versus Vitro Molar for Occlusoproximal ART Restorations: a RCT

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PACHECO Anna Luisa de Brito

2017-11-01

Full Text Available Abstract Good survival rates for single-surface Atraumatic Restorative Treatment (ART restorations have been reported, while multi-surface ART restorations have not shown similar results. The aim of this study was to evaluate the survival rate of occluso-proximal ART restorations using two different filling materials: Ketac Molar EasyMix (3M ESPE and Vitro Molar (DFL. A total of 117 primary molars with occluso-proximal caries lesions were selected in 4 to 8 years old children in Barueri city, Brazil. Only one tooth was selected per child. The subjetcs were randomly allocated in two groups according to the filling material. All treatments were performed following the ART premises and all restorations were evaluated after 2, 6 and 12 months. Restoration survival was evaluated using Kaplan-Meier survival analysis and Log-rank test, while Cox regression analysis was used for testing association with clinical factors (α = 5%. There was no difference in survival rate between the materials tested, (HR = 1.60, CI = 0.98–2.62, p = 0.058. The overall survival rate of restorations was 42.74% and the survival rate per group was Ketac Molar = 50,8% and Vitro Molar G2 = 34.5%. Cox regression test showed no association between the analyzed clinical variables and the success of the restorations. After 12 months evaluation, no difference in the survival rate of ART occluso-proximal restorations was found between tested materials.

Tooth-marked small theropod bone: an extremely rare trace

DEFF Research Database (Denmark)

Jacobsen, Aase Roland

2001-01-01

Tooth-marked dinosaur bones provide insight into feeding behaviours and biting strategies of theropod dinosaurs. The majority of theropod tooth marks reported to date have been found on herbivorous dinosaur bones, although some tyrannosaurid bones with tooth marks have also been reported. In 1988...

Association between Severity of Tooth Wear and Dentinal Hypersensitivity

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Ashok Ayer

2016-11-01

Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

Orientation and deformation of mineral crystals in tooth surfaces.

Science.gov (United States)

Fujisaki, Kazuhiro; Todoh, Masahiro; Niida, Atsushi; Shibuya, Ryota; Kitami, Shunsuke; Tadano, Shigeru

2012-06-01

Tooth enamel is the hardest material in the human body, and it is mainly composed of hydroxyapatite (HAp)-like mineral particles. As HAp has a hexagonal crystal structure, X-ray diffraction methods can be used to analyze the crystal structure of HAp in teeth. Here, the X-ray diffraction method was applied to the surface of tooth enamel to measure the orientation and strain of the HAp crystals. The c-axis of the hexagonal crystal structure of HAp was oriented to the surface perpendicular to the tooth enamel covering the tooth surface. Thus, the strain of HAp at the surface of teeth was measured by X-ray diffraction from the (004) lattice planes aligned along the c-axis. The X-ray strain measurements were conducted on tooth specimens with intact surfaces under loading. Highly accurate strain measurements of the surface of tooth specimens were performed by precise positioning of the X-ray irradiation area during loading. The strains of the (004) lattice plane were measured at several positions on the surface of the specimens under compression along the tooth axis. The strains were obtained as tensile strains at the labial side of incisor tooth specimens. In posterior teeth, the strains were different at different measurement positions, varying from tensile to compressive types. Copyright © 2012 Elsevier Ltd. All rights reserved.

Selective removal of esthetic composite restorations with spectral guided laser ablation

Science.gov (United States)

Yi, Ivana; Chan, Kenneth H.; Tsuji, Grant H.; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

2016-02-01

Dental composites are used for a wide range of applications such as fillings for cavities, adhesives for orthodontic brackets, and closure of gaps (diastemas) between teeth by esthetic bonding. Anterior restorations are used to replace missing, diseased and unsightly tooth structure for both appearance and function. When these restorations must be replaced, they are difficult to remove mechanically without causing excessive removal or damage to enamel because dental composites are color matched to teeth. Previous studies have shown that CO2 lasers have high ablation selectivity and are well suited for removal of composite on occlusal surfaces while minimizing healthy tissue loss. A spectral feedback guidance system may be used to discriminate between dental composite and dental hard tissue for selective ablation of composite material. The removal of composite restorations filling diastemas is more challenging due to the esthetic concern for anterior teeth. The objective of this study is to determine if composite spanning a diastema between anterior teeth can be removed by spectral guided laser ablation at clinically relevant rates with minimal damage to peripheral healthy tissue and with higher selectivity than a high speed dental handpiece.

Life of a Tooth: A Visual Timeline

Medline Plus

Full Text Available ... Child First See a Dentist? The History of Dental Advances Why is Oral Health Important for Men? What is Baby Bottle Tooth Decay? Learn what those dental words mean. The Life of a Tooth Home | ...

Inhibitory effect of interferon-γ on experimental tooth movement in mice.

Science.gov (United States)

Kohara, Haruka; Kitaura, Hideki; Yoshimatsu, Masako; Fujimura, Yuji; Morita, Yukiko; Eguchi, Toshiko; Yoshida, Noriaki

2012-09-01

The aim of this study was to investigate the effects of interferon (IFN)-γ on experimental tooth movement in mice using a murine experimental tooth movement model. An Ni-Ti closed-coil spring was inserted between the upper-anterior alveolar bones and the upper-left first molars in mice. We evaluated the relationship between local Ifn-γ mRNA levels and orthodontic tooth movement. In other experiments, IFN-γ was injected adjacent to each first molar every other day during tooth movement. After 12 days, the amount of tooth movement was measured. Tartrate-resistant acid phosphatase (TRAP)-positive cells at the pressure side of each experimental tooth were counted as osteoclasts. Local Ifn-γ mRNA expression increased with orthodontic tooth movement. The number of TRAP-positive cells increased on the pressure side of the first molar. In contrast, the degree of tooth movement and the number of TRAP-positive cells on the pressure side in IFN-γ-injected mice were less than those of control mice. IFN-γ was induced in experimental tooth movement, and could inhibit mechanical force-loaded osteoclastogenesis and tooth movement. These results suggest that IFN-γ might be useful in controlling orthodontic tooth movement because of its inhibitory action on excessive osteoclastogenesis during this movement.

Tooth bleaching and young adults in Nigeria: knowledge, experiences and intention.

Science.gov (United States)

Azodo, C C; Ogbomo, A C; Agbor, M A

2012-12-01

To assess the knowledge, experiences and intention to have tooth bleaching among young adults studying in a Nigerian University. A cross-section of part-time undergraduate students of University of Benin, Benin City, Nigeria were studied in 2010 using a self-administered questionnaire. About three-quarters 289 (72.4%) of the respondents reported awareness of at least one cause of tooth discoloration. A total of 143 (35.8%) of the respondents have heard of tooth bleaching with main sources of information being friends/relatives, dentists and the internet. One-third 132 (33.1%) of the respondents correctly identified that the aim of tooth bleaching was to make the teeth whiter. The respondents that had correct knowledge about mechanism, duration and complications of tooth bleaching were 51 (12.8%), 25 (6.3%) and 35 (8.8%) respectively. The major perceived benefits of tooth bleaching reported by the respondents were self confidence boost 152 (38.1%) and improvement of one's beauty 107 (26.8%). Out of the 68 (17.0%) respondents that have attempted tooth bleaching, 36 (52.9%) used tooth whitening toothpaste. Out of the 151 (37.8%) respondents that expressed intention of having tooth bleaching procedure, 32 (21.2%) would pursue the course, no matter the cost. In the studied population, knowledge of tooth discoloration was high, awareness and experiences of tooth bleaching were low but significant number expressed intention of having tooth bleaching. It is important that dentists increase oral health information particularly tooth bleaching information accessibility to the young adult population to improve the knowledge and prevent adverse effects.

Tooth Decay Process: How to Reverse It and Avoid a Cavity

Science.gov (United States)

... Health Info Health Topics Tooth Decay Tooth decay (dental caries) is damage to a tooth that can happen ... Clinical Trials Show All Clinical Trials Data & Statistics Dental caries (tooth decay) remains the most prevalent chronic disease ...

Tooth polishing: The current status

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Madhuri Alankar Sawai

2015-01-01

Full Text Available Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients′ need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

Extent of tooth decay in the mouth and increased need for replacement of dental restorations: the New England Children's Amalgam Trial.

Science.gov (United States)

Trachtenberg, Felicia; Maserejian, Nancy Nairi; Tavares, Mary; Soncini, Jennifer Ann; Hayes, Catherine

2008-01-01

The purpose of this study was to assess the relationship between baseline caries experience and the restoration replacement rate in children. The 5-year New England Children's Amalgam Trial recruited 534 6- to 10-year-old children with 2 or more carious posterior teeth. The association between decoy and longevity of restorations was assessed. Restorations with no follow-up (N = 391) were excluded from analysis. The average follow-up was 3.0 +/- 1.6 years in 489 children. Restorations with follow-up (N = 3,604) were placed in mouths with a median of 15 dfs/DFS and 8 dft/DFT. The need for replacement increased significantly (P or = 14 dfs/DFS needed replacement, compared to 9% for 2 to 5 dfs/DFS. Comparing dft/DFT after 5 years of follow-up, there was a 23% replacement rate for > or = 12 dft/DFT compared to 10% for 2 to 3 dft/DFT. Decoy in the mouth had a greater association with the need for replacement due to new caries compared to replacement due to recurrent caries. Children with more decoy at the time of restoration placement were at higher risk for replacement of restorations.

Cracked tooth syndrome: A report of three cases.

Science.gov (United States)

Sadasiva, Kadandale; Ramalingam, Sathishmuthukumar; Rajaram, Krishnaraj; Meiyappan, Alagappan

2015-08-01

Cracked tooth syndrome (CTS), the term was coined by Cameron in 1964, which refers to an incomplete fracture of a vital posterior tooth extending to the dentin and occasionally into the pulp. CTS has always been a nightmare to the patient because of its unpredictable symptoms and a diagnostic dilemma for the dental practitioner due to its variable, bizarre clinical presentation. The treatment planning and management of CTS has also given problems and challenges the dentist as there is no specific treatment option. The management of CTS varies from one case to another or from one tooth to another in the same individual based on the severity of the symptoms and depth of tooth structure involved. After all, the prognosis of such tooth is still questionable and requires continuous evaluation. This article aims at presenting a series three cases of CTS with an overview on the clinical presentation, diagnosis and the different treatment options that varies from one case to another.

Combined periodontic-orthodonticendodontic interdisciplinary approach in the treatment of periodontally compromised tooth

OpenAIRE

Deepa, D; Mehta, D. S.; Puri, Viren K.; Shetty, Sadashiva

2010-01-01

Orthodontic treatment in adult patients is one of the most frequently encountered components involving multidisciplinary approaches. In the present report, a 28-year-old male patient was treated for localized chronic periodontitis with pocket formation, mobility, pathologic migration and malalignment of maxillary left lateral incisor tooth #22. The periodontal therapy included motivation, education and oral-hygiene instructions (O.H.I.), scaling and root planing and periodontal flap surgery. ...

Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite.

Science.gov (United States)

Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

2016-01-01

To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (Pcomposite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations.

Direct restorative treatment of dental erosion caused by gastroesophageal reflux disease associated with bruxism: a case report.

Science.gov (United States)

Vidal, Cristina de Mattos Pimenta; Catelan, Anderson; Briso, André Luiz Fraga; dos Santos, Paulo Henrique

2011-09-01

Gastroesophageal reflux disease (GERD) is a gastrointestinal disorder in which stomach acids are chronically regurgitated into the esophagus and oral cavity. Continual exposure of the teeth to these acids can cause severe tooth wear. Dentists are often the first healthcare professionals to diagnose dental erosion in patients with GERD. This article presents a case report of a 27-year-old male smoker with tooth wear and dentin sensitivity caused by GERD associated with bruxism. After diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow-up with counseling on dietary and smoking habits, as well as management of the gastric disorders with medication. GERD management and the dental treatment performed for the eroded dentition are described, including diagnosis, treatment planning, and restorative therapy.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur.

Science.gov (United States)

Liu, Min; Reed, David A; Cecchini, Giancarlo M; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S; Monahan, Richard; Luan, Xianghong; Diekwisch, Thomas G H

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur

Directory of Open Access Journals (Sweden)

Min eLiu

2016-05-01

Full Text Available Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids versus snakes: (i the orientation of replacement teeth compared to the major tooth axis, (ii the occurrence of resorption pits, and (iii the mode of tooth implantation/attachment to the tooth bearing element. The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as

Factors associated with tooth loss and prosthodontic status among Sudanese adults.

Science.gov (United States)

Khalifa, Nadia; Allen, Patrick F; Abu-bakr, Neamat H; Abdel-Rahman, Manar E

2012-01-01

A study was conducted to determine the degree of tooth loss, factors influencing tooth loss, and the extent of prosthodontic rehabilitation in Sudanese adults (≥ 16 years old) attending outpatient clinics in Khartoum State. Pearson and multivariate analyses were used to examine the relationships between tooth loss and specific characteristics determined through interviews and clinical examinations. The mean number of missing teeth was 3.6 (SD, 4.9) and the prevalence of edentulism was 0.1%. The prevalence of tooth loss (missing at least one tooth) was 78%; 66.9% of tooth loss was due to caries, and 11.2% was attributable to other reasons. Prosthetic replacement of missing teeth was evident in 3%, whereas a need for prosthetic replacement was evident in 57%. Having teeth was associated with age, gender, and socioeconomic status; tooth loss due to caries was associated with age, tribe, frequency of tooth-brushing, and a low rate of dental consultation. Tooth loss due to other reasons was associated with age, tribe, education, periodontal pocketing, tobacco use, tooth wear, and prosthetic status. The results of the present study indicated that the major cause of tooth loss was dental caries, thus emphasizing the importance of a public prevention-based healthcare program. Replacement of missing teeth was uncommon in the study subjects, which may reflect lack of access to this type of oral healthcare.

Contaminated tooth brushes-potential threat to oral and general health

Directory of Open Access Journals (Sweden)

Rashmi Naik

2015-01-01

Full Text Available Background: Tooth brushing is most common method of maintaining oral hygiene. In removing plaque and other soft debris from the teeth, tooth brushes become contaminated with bacteria, blood, saliva and oral debris. These contaminated tooth brushes can be a source of infection. Aims and objectives: The aim of the present study was to evaluate the presence of microorganisms in the tooth brushes and to investigate the effect of disinfectants such as chlorhexidine gluconate, sodium hypochlorite and water to decontaminate them. Materials and Methods: Twenty-one children were asked to brush their teeth for 5 days with a tooth brush. The tooth brushes were put in Robertson′s Cooked Meat broth and were observed for growth of Streptococcal microorganisms. These tooth brushes were then placed in disinfectants such as 0.2% chlorhexidine gluconate (Group I, 1% sodium hypochlorite (Group II and water (Group III for 24 hrs and then cultured again. Reduction of growth of microorganisms was seen in Group I, Group II and remnants of growth seen in Group III. Conclusion: We conclude that the use of disinfectant for a tooth brush is a must for every individual at least at regular intervals.

Determining the Response of Periodontal Teeth is Limited to Defects in the Integrity of the Dentition Loading

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Kopytov А.А.

2011-03-01

Full Text Available Stability of the tooth characterizes its ability to perceive occlusal load. As the footprint specific loading functioning periodontium increases. To neutralize the impact of the load component of periodontitis should restore the integrity of the dentition

Restorative Justice: New Horizons in Juvenile Offender Counseling

Science.gov (United States)

Ryals, John S. Jr.

2004-01-01

Treatment strategies of the juvenile justice system focus singularly on rehabilitation of offenders, and victims and communities are excluded from the rehabilitative process. Restorative justice views victims and communities as essential components in rehabilitative efforts. In this article, the principles and practices of restorative justice,…

Effect of Melamine Sponge on Tooth Stain Removal.

Science.gov (United States)

Otsuka, Takero; Kawata, Toshitsugu

2015-01-01

To investigate the stain removal ability of melamine sponge before aesthetic tooth whitening in extracted teeth. Melamine sponge of thickness 40 mm was compressed and the destruction of the partition wall structure during the compression process was examined under a stereoscopic microscope. An extracted human tooth was cleaned by normal polishing or with melamine sponge for 90 s. To evaluate the stain level, the tooth surfaces were photographed under a stereoscopic microscope at 0, 30, 60 and 90 s. The residual stained region was traced in a high-magnification photograph, and the stain intensity was presented as a change, relative to the intensity before the experiment (0 s). Mechanical cleaning by toothbrushing produced polishing scratches on the tooth surface, whereas use of the melamine sponge resulted in only minimal scratches. As the compression level increased, the stain-removing effect tended to become stronger. Melamine sponge can remove stains from the tooth surface more effectively and less invasively compared to a conventional toothbrush. As no new scratches are made on the tooth surface when using a melamine sponge brush, the risk of re-staining is reduced. Cleaning using a melamine sponge brush can be easily and effectively performed at home and in a dental office.

An automatic tooth preparation technique: A preliminary study

Science.gov (United States)

Yuan, Fusong; Wang, Yong; Zhang, Yaopeng; Sun, Yuchun; Wang, Dangxiao; Lyu, Peijun

2016-04-01

The aim of this study is to validate the feasibility and accuracy of a new automatic tooth preparation technique in dental healthcare. An automatic tooth preparation robotic device with three-dimensional motion planning software was developed, which controlled an ultra-short pulse laser (USPL) beam (wavelength 1,064 nm, pulse width 15 ps, output power 30 W, and repeat frequency rate 100 kHz) to complete the tooth preparation process. A total of 15 freshly extracted human intact first molars were collected and fixed into a phantom head, and the target preparation shapes of these molars were designed using customised computer-aided design (CAD) software. The accuracy of tooth preparation was evaluated using the Geomagic Studio and Imageware software, and the preparing time of each tooth was recorded. Compared with the target preparation shape, the average shape error of the 15 prepared molars was 0.05-0.17 mm, the preparation depth error of the occlusal surface was approximately 0.097 mm, and the error of the convergence angle was approximately 1.0°. The average preparation time was 17 minutes. These results validated the accuracy and feasibility of the automatic tooth preparation technique.

Esthetic evaluation of single-tooth implants in the anterior mandible.

Science.gov (United States)

Hof, Markus; Tepper, Gabor; Koller, Barbara; Krainhöfner, Martin; Watzek, Georg; Pommer, Bernhard

2014-09-01

Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible. Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES = Pink Esthetic Score, PI = Papilla Index, SES = Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence. Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs  = 0.62, PES/SES: rs  = -0.73, PI/SES: rs  = -0.48) was highly significant (P ≤ 0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor. Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

CT Image Sequence Restoration Based on Sparse and Low-Rank Decomposition

Science.gov (United States)

Gou, Shuiping; Wang, Yueyue; Wang, Zhilong; Peng, Yong; Zhang, Xiaopeng; Jiao, Licheng; Wu, Jianshe

2013-01-01

Blurry organ boundaries and soft tissue structures present a major challenge in biomedical image restoration. In this paper, we propose a low-rank decomposition-based method for computed tomography (CT) image sequence restoration, where the CT image sequence is decomposed into a sparse component and a low-rank component. A new point spread function of Weiner filter is employed to efficiently remove blur in the sparse component; a wiener filtering with the Gaussian PSF is used to recover the average image of the low-rank component. And then we get the recovered CT image sequence by combining the recovery low-rank image with all recovery sparse image sequence. Our method achieves restoration results with higher contrast, sharper organ boundaries and richer soft tissue structure information, compared with existing CT image restoration methods. The robustness of our method was assessed with numerical experiments using three different low-rank models: Robust Principle Component Analysis (RPCA), Linearized Alternating Direction Method with Adaptive Penalty (LADMAP) and Go Decomposition (GoDec). Experimental results demonstrated that the RPCA model was the most suitable for the small noise CT images whereas the GoDec model was the best for the large noisy CT images. PMID:24023764

A Study of Objective Assessment for Tooth Cavity Preparation at Preclinical Restorative Dentistry. : Part 1. Student Self-assessment for Tooth Cavity

OpenAIRE

横内,厚雄/畑,良明/荊木,裕司/松田,浩一; ヨコウチ,アツオ/ハタ,ヨシアキ/イバラキ,ユウジ/マツダ,コウイチ; YOKOUCHI,Atsuo/HATA,Yoshiaki/IBARAKI,Yuji/MATSUDA,Koichi

1994-01-01

In preclimcal restorative technique courses, traditional evalution methods established by dental educators were used with student produced specimens and interviews related to the performance of the task. Although defined criteria were present, instructors tended to evaluate subjectively and there appears to be a need for improving the method of evaluation. Self-assessment is a new and important aspect in educations. Students should be trained and expected to critically evaluate their work Onl...

Periodontal profile classes predict periodontal disease progression and tooth loss.

Science.gov (United States)

Morelli, Thiago; Moss, Kevin L; Preisser, John S; Beck, James D; Divaris, Kimon; Wu, Di; Offenbacher, Steven

2018-02-01

Current periodontal disease taxonomies have limited utility for predicting disease progression and tooth loss; in fact, tooth loss itself can undermine precise person-level periodontal disease classifications. To overcome this limitation, the current group recently introduced a novel patient stratification system using latent class analyses of clinical parameters, including patterns of missing teeth. This investigation sought to determine the clinical utility of the Periodontal Profile Classes and Tooth Profile Classes (PPC/TPC) taxonomy for risk assessment, specifically for predicting periodontal disease progression and incident tooth loss. The analytic sample comprised 4,682 adult participants of two prospective cohort studies (Dental Atherosclerosis Risk in Communities Study and Piedmont Dental Study) with information on periodontal disease progression and incident tooth loss. The PPC/TPC taxonomy includes seven distinct PPCs (person-level disease pattern and severity) and seven TPCs (tooth-level disease). Logistic regression modeling was used to estimate relative risks (RR) and 95% confidence intervals (CI) for the association of these latent classes with disease progression and incident tooth loss, adjusting for examination center, race, sex, age, diabetes, and smoking. To obtain personalized outcome propensities, risk estimates associated with each participant's PPC and TPC were combined into person-level composite risk scores (Index of Periodontal Risk [IPR]). Individuals in two PPCs (PPC-G: Severe Disease and PPC-D: Tooth Loss) had the highest tooth loss risk (RR = 3.6; 95% CI = 2.6 to 5.0 and RR = 3.8; 95% CI = 2.9 to 5.1, respectively). PPC-G also had the highest risk for periodontitis progression (RR = 5.7; 95% CI = 2.2 to 14.7). Personalized IPR scores were positively associated with both periodontitis progression and tooth loss. These findings, upon additional validation, suggest that the periodontal/tooth profile classes and the derived

Safety issues of tooth whitening using peroxide-based materials.

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Li, Y; Greenwall, L

2013-07-01

In-office tooth whitening using hydrogen peroxide (H₂O₂) has been practised in dentistry without significant safety concerns for more than a century. While few disputes exist regarding the efficacy of peroxide-based at-home whitening since its first introduction in 1989, its safety has been the cause of controversy and concern. This article reviews and discusses safety issues of tooth whitening using peroxide-based materials, including biological properties and toxicology of H₂O₂, use of chlorine dioxide, safety studies on tooth whitening, and clinical considerations of its use. Data accumulated during the last two decades demonstrate that, when used properly, peroxide-based tooth whitening is safe and effective. The most commonly seen side effects are tooth sensitivity and gingival irritation, which are usually mild to moderate and transient. So far there is no evidence of significant health risks associated with tooth whitening; however, potential adverse effects can occur with inappropriate application, abuse, or the use of inappropriate whitening products. With the knowledge on peroxide-based whitening materials and the recognition of potential adverse effects associated with the procedure, dental professionals are able to formulate an effective and safe tooth whitening regimen for individual patients to achieve maximal benefits while minimising potential risks.

Effect of light energy on peroxide tooth bleaching.

Science.gov (United States)

Luk, Karen; Tam, Laura; Hubert, Manfred

2004-02-01

Light-activated bleaching is a method of tooth whitening. The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources. The authors randomly assigned 250 extracted human teeth halves into experimental groups (n = 10). A placebo gel (control), a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light (control); a halogen curing light; an infrared, or IR, light; an argon laser; or a carbon dioxide, or CO2, laser. Color changes were evaluated immediately, one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer. The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer. Color and temperature changes were significantly affected by an interaction of the bleach and light variables. The application of lights significantly improved the whitening efficacy of some bleach materials, but it caused significant temperature increases in the outer and inner tooth surfaces. The IR and CO2 laser lights caused the highest tooth temperature increases. Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used, as well as the potential risks of heating teeth. A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching.

Esthetic evaluation of maxillary single-tooth implants in the esthetic zone

Science.gov (United States)

Cho, Hae-Lyung; Lee, Jae-Kwan; Um, Heung-Sik

2010-01-01

Purpose The aim of this study is to assess the influence exerted by the observer's dental specialization and compare patients' opinion with observers' opinion of the esthetics of maxillary single-tooth implants in the esthetic zone. Methods Forty-one adult patients, who were treated with a single implant in the esthetic zone, were enrolled in this study. Eight observers (2 periodontists, 2 prosthodontists, 2 orthodontists and 2 senior dental students) applied the pink esthetic score (PES)/white esthetic score (WES) to 41 implant-supported single restorations twice with an interval of 4 weeks. We used a visual analog scale (VAS) to assess the patient's satisfaction with the treatment outcome from an esthetic point of view. Results In the PES/WES, very good and moderate intraobserver agreements were noted between the first and second rating. The mean total PES/WES was 11.19 ± 3.59. The mean PES was 5.17 ± 2.29 and mean WES was 6.02 ± 1.96. In the total PES/WES, the difference between the groups was not significant. However, in the WES, the difference between the groups was significant and prosthodontists were found to have assigned poorer ratings than the other groups. Periodontists gave higher ratings than prosthodontists and senior dental students. Orthodontists were clearly more critical than the other observers. The statistical analysis revealed statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth. However, the correlation between the total PES/WES and the VAS score for the first premolar was not statistically significant. Conclusions The PES/WES is an objective tool in rating the esthetics of implant supported single crowns and adjacent soft tissues. Orthodontists were the most critical observers, while periodontists were more generous than other observers. The statistical analysis revealed a statistically significant correlation between patients' esthetic perception and dentists

Tunnel restorations using glass ionomer or glass cermet: in vitro marginal ridge fracture and microleakage.

Science.gov (United States)

Shetty, R; Munshi, A K

1996-01-01

The purpose of this in vitro study was to compare the marginal ridge fracture resistance and microleakage following restorations of partial tunnel preparations using glass ionomer and glass cermet cements. Sixty eight sound premolars were selected for this study and were divided randomly into six groups. A standardized partial tunnel preparation was done on all the teeth except specimens belonging to Group I. The partial tunnel preparations of Groups III & V were restored with glass ionomer and that of Groups IV & VI were restored with glass cermet. The teeth belonging to Groups I, II, III & IV were subjected to marginal ridge fracture resistance testing. The teeth of Groups V & VI were tested for microleakage after immersing them in 5% methylene blue solution for 4 hours. The results indicated that the teeth restored with glass cermet were marginally better than that with glass ionomer in terms of marginal ridge fracture resistance. Both the materials failed to reinforce the marginal ridge to the level of an intact tooth. The microleakage which occurred around both the materials were statistically insignificant, but on comparison glass ionomer showed better results. Hence, glass ionomer is preferred as a restorative material for partial tunnel preparations because of additional inherent advantages like superior esthetics and fluoride leachability.

Advances and perspectives in tooth tissue engineering.

Science.gov (United States)

Monteiro, Nelson; Yelick, Pamela C

2017-09-01

Bio-engineered teeth that can grow and remodel in a manner similar to that of natural teeth have the potential to serve as permanent replacements to the currently used prosthetic teeth, such as dental implants. A major challenge in designing functional bio-engineered teeth is to mimic both the structural and anisotropic mechanical characteristics of the native tooth. Therefore, the field of dental and whole tooth regeneration has advanced towards the molecular and nanoscale design of bio-active, biomimetic systems, using biomaterials, drug delivery systems and stem cells. The focus of this review is to discuss recent advances in tooth tissue engineering, using biomimetic scaffolds that provide proper architectural cues, exhibit the capacity to support dental stem cell proliferation and differentiation and sequester and release bio-active agents, such as growth factors and nucleic acids, in a spatiotemporal controlled manner. Although many in vitro and in vivo studies on tooth regeneration appear promising, before tooth tissue engineering becomes a reality for humans, additional research is needed to perfect methods that use adult human dental stem cells, as opposed to embryonic dental stem cells, and to devise the means to generate bio-engineered teeth of predetermined size and shape. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Atraumatic restorative treatment versus conventional restorative treatment for managing dental caries.

Science.gov (United States)

Dorri, Mojtaba; Martinez-Zapata, Maria José; Walsh, Tanya; Marinho, Valeria Cc; Sheiham Deceased, Aubrey; Zaror, Carlos

2017-12-28

Dental caries is a sugar-dependent disease that damages tooth structure and, due to loss of mineral components, may eventually lead to cavitation. Dental caries is the most prevalent disease worldwide and is considered the most important burden of oral health. Conventional treatment methods (drill and fill) involve the use of rotary burs under local anaesthesia. The need for an electricity supply, expensive handpieces and highly trained dental health personnel may limit access to dental treatment, especially in underdeveloped regions.To overcome the limitations of conventional restorative treatment, the Atraumatic Restorative Treatment (ART) was developed, mainly for treating caries in children living in under-served areas of the world where resources and facilities such as electricity and trained manpower are limited. ART is a minimally invasive approach which involves removal of decayed tissue using hand instruments alone, usually without use of anaesthesia and electrically driven equipment, and restoration of the dental cavity with an adhesive material (glass ionomer cement (GIC), composite resins, resin-modified glass-ionomer cement (RM-GICs) and compomers). To assess the effects of Atraumatic Restorative Treatment (ART) compared with conventional treatment for managing dental caries lesions in the primary and permanent teeth of children and adults. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 1), MEDLINE Ovid (1946 to 22 February 2017), Embase Ovid (1980 to 22 February 2017), LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 22 February 2017) and BBO BIREME Virtual Health Library (Bibliografia Brasileira de Odontologia; 1986 to 22 February 2017). The US National Institutes of Health Trials Registry (Clinical

In vitro evaluation of microleakage in restored teeth with synthetic resins by neutrongraphy

Energy Technology Data Exchange (ETDEWEB)

Barbosa, A.L.N.; Crispim, V.R., E-mail: abarbosa@ien.gov.b, E-mail: verginia@con.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

2011-07-01

The goal of the present study was to evaluate, using neutron graphic images, microleakage in teeth that were treated with resins. Teeth samples were drilled, producing wells with similar dimensions in each tooth. Afterwards, they were thoroughly filled with different resins to avoid voids. In preliminary tests, four different resins were used, and after submitted to neutron radiography their images were analyzed. The results of this trial showed good adherent for all the resins used, and since no micro leakage were seen on the images, the restoration procedure was successfully. (author)

Reasons for Retreatment of Amalgam and Composite Restorations among the Patients Referring to Tabriz Faculty of Dentistry

Directory of Open Access Journals (Sweden)

Siavash Savadi Oskoee

2007-06-01

Full Text Available

Background and aims. Retreatment of existing restorations not only requires a lot of money and time but also there is a danger of weakening tooth structure and irritating the pulp. Since awareness of the reasons for the retreatment of teeth will save the teeth from possible future failure, the aim of this study was to assess the reasons for retreatment of amalgam and composite restorations in patients referring to Tabriz Faculty of Dentistry.

Materials and methods. In this descriptive study, the subjects had previously received an amalgam or a composite restoration in the Operative Department by dental students and were judged to need retreatment in their second visit. A total of 300 defective teeth were selected by simple random sampling method. The data was collected through examination and questionnaires and analyzed using chi-square test.

Results. There was a statistically significant association between the type of the restorative material and the reason for retreatment (p=0.001.

Conclusion. Although the reasons for the retreatment of amalgam and composite restorations were different, recurrent caries was the main reason for the retreatment for both restorative materials.

Factors influencing bonding fixed restorations

Directory of Open Access Journals (Sweden)

Medić Vesna

2008-01-01

Full Text Available INTRODUCTION Crown displacement often occurs because the features of tooth preparations do not counteract the forces directed against restorations. OBJECTIVE The purpose of this study was to evaluate the effect of preparation designs on retention and resistance of fixed restorations. METHOD The study was performed on 64 differently sized stainless steel dies. Also, caps which were used for evaluated retention were made of stainless steel for each die. After cementing the caps on experimental dies, measuring of necessary tensile forces to separate cemented caps from dies was done. Caps, which were made of a silver-palladium alloy with a slope of 60° to the longitudinal axis formed on the occlusal surface, were used for evaluating resistance. A sudden drop in load pressure recorded by the test machine indicated failure for that cap. RESULTS A significant difference was found between the tensile force required to remove the caps from the dies with different length (p<0.05 and different taper (p<0.01. The greatest retentive strengths (2579.2 N and 2989.8 N were noticed in experimental dies with the greatest length and smallest taper. No statistically significant (p>0.05 differences were found between tensile loads for caps cemented on dies with different diameter. Although there was an apparent slight increase in resistance values for caps on dies with smaller tapers, the increase in resistance for those preparation designs was not statistically significant. There was a significant difference among the resistance values for caps on dies with different length (p<0.01 and diameter (p<0.05. CONCLUSION In the light of the results obtained, it could be reasonably concluded that retention and resistance of the restoration is in inverse proportion to convergence angle of the prepared teeth. But, at a constant convergence angle, retention and resistance increase with rising length and diameter.

Autotransplantation donor tooth site harvesting using piezosurgery.

Science.gov (United States)

Ylikontiola, Leena P; Sándor, George K

2016-01-01

The harvesting of a tooth as a candidate for tooth autotransplantation requires that the delicate dental tissues around the tooth be minimally traumatized. This is especially so for the periradicular tissues of the tooth root and the follicular tissues surrounding the crown. The aim of this report is to describe the use of piezosurgery as an attempt at morbidity reduction in the harvesting of teeth for autotransplantation. A piezosurgical handpiece and its selection of tips were easily adapted to allow the harvesting and delivery of teeth for autotransplantation purposes. Twenty premolar teeth were harvested using a piezosurgical device. The harvested teeth were subsequently successfully autotransplanted. All twenty teeth healed in a satisfactory manner without excessive mobility or ankyloses. Piezosurgery avoids some of the traumatic aspects of harvesting teeth and removing bone which are associated with thermal damage from the use of conventional rotary instruments or saws. Piezosurgery can be adapted to facilitate the predictable harvesting of teeth for autotransplantation purposes.

Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

Science.gov (United States)

Zhang, Zhihong; Wang, Xiaoyang; Tong, Jin; Stephen, Carr

2018-01-01

A highly efficient soil-burrowing dung beetle possesses an intricate outer contour curve on its foreleg end-tooth. This study was carried out based on evidence that this special outer contour curve has the potential of reducing soil penetration resistance and could enhance soil-burrowing efficiency. A toothed wheel is a typical agricultural implement for soil imprinting, to increase its working efficiency; the approach of the bionic geometrical structure was utilized to optimize the innovative shape of imprinting toothed wheel. Characteristics in the dung beetle's foreleg end-tooth were extracted and studied by the edge detection technique. Then, this special outer contour curve was modeled by a nine-order polynomial function and used for the innovative design of imprinting the tooth's cutting edge. Both the conventional and bionic teeth were manufactured, and traction tests in a soil bin were conducted. Taking required draft force and volume of imprinted microbasin as the evaluating indexes, operating efficiency and quality of different toothed wheels were compared and investigated. Results indicate that compared with the conventional toothed wheel, a bionic toothed wheel possesses a better forward resistance reduction property against soil and, meanwhile, can enhance the quality of soil imprinting by increasing the volume of the created micro-basin.

The Effect of Composite Thickness on the Stress Distribution Pattern of Restored Premolar Teeth with Cusp Reduction.

Science.gov (United States)

Panahandeh, Narges; Torabzadeh, Hassan; Ziaee, Nargess; Mahdian, Mina; Tootiaee, Bahman; Ghasemi, Amir

2017-07-01

Different thicknesses of restorative material can alter the stress distribution pattern in remaining tooth structure. The assumption is that a thicker composite restoration will induce a higher fracture resistance. Therefore, the present study evaluated the effect of composite thickness on stress distribution in a restored premolar with cusp reduction. A 3D solid model of a maxillary second premolar was prepared and meshed. MOD cavities were designed with different cusp reduction thicknesses (0, 0.5, 1, 1.5, 2.5 mm). Cavities were restored with Valux Plus composite. They were loaded with 200 N force on the occlusal surface in the direction of the long axis. Von Mises stresses were evaluated with Abaqus software. Stress increased from occlusal to gingival and was maximum in the cervical region. The stressed area in the palatal cusp was more than that of the buccal cusp. Increasing the thickness of composite altered the shear stress to compressive stress in the occlusal area of the teeth. The model with 2.5 mm cusp reduction exhibited the most even stress distribution. © 2015 by the American College of Prosthodontists.

The science and practice of river restoration

Science.gov (United States)

Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.

2015-08-01

River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.

The demand for preventive and restorative dental services.

Science.gov (United States)

Meyerhoefer, Chad D; Zuvekas, Samuel H; Manski, Richard

2014-01-01

Chronic tooth decay is the most common chronic condition in the United States among children ages 5-17 and also affects a large percentage of adults. Oral health conditions are preventable, but less than half of the US population uses dental services annually. We seek to examine the extent to which limited dental coverage and high out-of-pocket costs reduce dental service use by the nonelderly privately insured and uninsured. Using data from the 2001-2006 Medical Expenditure Panel Survey and an American Dental Association survey of dental procedure prices, we jointly estimate the probability of using preventive and both basic and major restorative services through a correlated random effects specification that controls for endogeneity. We found that dental coverage increased the probability of preventive care use by 19% and the use of restorative services 11% to 16%. Both conditional and unconditional on dental coverage, the use of dental services was not sensitive to out-of-pocket costs. We conclude that dental coverage is an important determinant of preventive dental service use, but other nonprice factors related to consumer preferences, especially education, are equal if not stronger determinants. Copyright © 2013 John Wiley & Sons, Ltd.

Dental health state utility values associated with tooth loss in two contrasting cultures.

Science.gov (United States)

Nassani, M Z; Locker, D; Elmesallati, A A; Devlin, H; Mohammadi, T M; Hajizamani, A; Kay, E J

2009-08-01

The study aimed to assess the value placed on oral health states by measuring the utility of mouths in which teeth had been lost and to explore variations in utility values within and between two contrasting cultures, UK and Iran. One hundred and fifty eight patients, 84 from UK and 74 from Iran, were recruited from clinics at University-based faculties of dentistry. All had experienced tooth loss and had restored or unrestored dental spaces. They were presented with 19 different scenarios of mouths with missing teeth. Fourteen involved the loss of one tooth and five involved shortened dental arches (SDAs) with varying numbers of missing posterior teeth. Each written description was accompanied by a verbal explanation and digital pictures of mouth models. Participants were asked to indicate on a standardized Visual Analogue Scale how they would value the health of their mouth if they had lost the tooth/teeth described and the resulting space was left unrestored. With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, the mouth with the upper central incisor missing attracted the lowest utility value in both samples (UK = 0.16; Iran = 0.06), while the one with a missing upper second molar the highest utility values (0.42, 0.39 respectively). In both countries the utility value increased as the tooth in the scenario moved from the anterior towards the posterior aspect of the mouth. There were significant differences in utility values between UK and Iranian samples for four scenarios all involving the loss of anterior teeth. These differences remained after controlling for gender, age and the state of the dentition. With respect to the SDA scenarios, a mouth with a SDA with only the second molar teeth missing in all quadrants attracted the highest utility values, while a mouth with an extreme SDA with both missing molar and premolar teeth in all quadrants attracted the lowest utility values. The study

Tooth brushing among 11- to 15-year-olds in Denmark

DEFF Research Database (Denmark)

Bast, L. S.; Holstein, B. E.; Nordahl, Helene

2015-01-01

brushing. Results: 10,607 respondents: a response rate of 88.3%. Boys of lower social class had higher odds ratio (OR) of infrequent tooth brushing than girls: 1.98 (95% confidence interval 1.62-2.41) vs 1.80 (1.53-2.24). Immigrants and descendants had higher odds compared to adolescents of Danish origin......Objective: Regular tooth brushing in adolescence predicts stable tooth brushing habits later in life. Differences in tooth brushing habits by ethnic background and socioeconomic position have been suggested. We investigated migration status and social class in relation to infrequent tooth brushing...... both separately and combined. Methods: The study population was 11-15 year-olds chosen from a clustered random sample of schools. Univariate and multivariate logistic regression analyses estimated the separate and combined effects of migration status and social class on less than twice daily tooth...

Stem cells for tooth engineering

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G Bluteau

2008-07-01

Full Text Available Tooth development results from sequential and reciprocal interactions between the oral epithelium and the underlying neural crest-derived mesenchyme. The generation of dental structures and/or entire teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin and enamel. Although mesenchymal stem cells from different origins have been extensively studied in their capacity to form dentin in vitro, information is not yet available concerning the use of epithelial stem cells. The odontogenic potential resides in the oral epithelium and thus epithelial stem cells are necessary for both the initiation of tooth formation and enamel matrix production. This review focuses on the different sources of stem cells that have been used for making teeth in vitro and their relative efficiency. Embryonic, post-natal or even adult stem cells were assessed and proved to possess an enormous regenerative potential, but their application in dental practice is still problematic and limited due to various parameters that are not yet under control such as the high risk of rejection, cell behaviour, long tooth eruption period, appropriate crown morphology and suitable colour. Nevertheless, the development of biological approaches for dental reconstruction using stem cells is promising and remains one of the greatest challenges in the dental field for the years to come.

Tooth color: effects on judgments of attractiveness and age.

Science.gov (United States)

Grosofsky, Alexis; Adkins, Sarah; Bastholm, Robert; Meyer, Leif; Krueger, Lisa; Meyer, Joshua; Torma, Peter

2003-02-01

Tooth whitening has become a very popular procedure. Advertisements for whitening products imply that whiter teeth are more attractive than yellower teeth. We tested this idea empirically by manipulating the tooth color of pictures of male and female targets. Participants' ratings of attractiveness were not influenced by tooth color. Exp. 2 yielded a negative correlation between attractiveness and age ratings: targets judged to be older were rated as less attractive. Unless whiter teeth help in some other way, e.g., improved self-esteem or confidence, it seems that tooth whitening procedures or products are not associated with increased attractiveness to others.

Side effects of external tooth bleaching

DEFF Research Database (Denmark)

Bruzell, E.M.; Pallesen, Ulla; Thoresen, N.R.

2013-01-01

Objective The study was performed to assess the risk of at-home and in-office bleaching procedures, and to recognise potential predictors for side effects. Design Multi-centre, questionnaire-based prospective study with follow-ups at around 14 days and around one year post-treatment. Setting...... General practices and university clinics during the years 2007‑2009 in Scandinavia. Subjects Patients with tooth bleaching as part of the treatment plan. Results The prevalence of experienced tooth sensitivity at first follow-up was independent of bleaching procedure (at-home = 50.3% [n = 143]; in...... attributed to the bleaching treatment in the at-home and in-office groups, respectively. Predictors for side effects were tooth sensitivity, surface loss and gingivitis when observed at inclusion. Treatment-related predictors were bleaching concentration and contact between tray and gingiva. Conclusions...

In vitro compressive fracture resistance of human maxillary first premolar with different mesial occlusal distal cavity

Directory of Open Access Journals (Sweden)

Wen-Chou Wu

2014-09-01

Conclusion: A bonded ceramic restoration restores the fracture load of a tooth comparable to an intact tooth independent of the examined design parameters, whereas the fracture loads of composite-resin-restored teeth were dependent on cavity widths. Cavity pulpal floor depth is not a significant factor of cusp fracture resistance in a tooth restored with either a ceramic inlay or composite resin.

Clinical evaluation of a newly designed orthodontic tooth brush - A clinical study

Directory of Open Access Journals (Sweden)

C S Saimbi

2009-01-01

In this study, the newly designed orthodontic tooth brush is compared with an ordinary tooth brush. Results of this study show that the newly designed orthodontic tooth brush is superior in its cleaning efficiency as compared to the ordinary tooth brush. The results show that plaque removing capacity of orthodontic tooth brush is nearly 95-99%.

The role of microbial iron reduction in the formation of Proterozoic molar tooth structures

Science.gov (United States)

Hodgskiss, Malcolm S. W.; Kunzmann, Marcus; Poirier, André; Halverson, Galen P.

2018-01-01

Molar tooth structures are poorly understood early diagenetic, microspar-filled voids in clay-rich carbonate sediments. They are a common structure in sedimentary successions dating from 2600-720 Ma, but do not occur in rocks older or younger, with the exception of two isolated Ediacaran occurrences. Despite being locally volumetrically significant in carbonate rocks of this age, their formation and disappearance in the geological record remain enigmatic. Here we present iron isotope data, supported by carbon and oxygen isotopes, major and minor element concentrations, and total organic carbon and sulphur contents for 87 samples from units in ten different basins spanning ca. 1900-635 Ma. The iron isotope composition of molar tooth structures is almost always lighter (modal depletion of 2‰) than the carbonate or residue components in the host sediment. We interpret the isotopically light iron in molar tooth structures to have been produced by dissimilatory iron reduction utilising Fe-rich smectites and Fe-oxyhydroxides in the upper sediment column. The microbial conversion of smectite to illite results in a volume reduction of clay minerals (∼30%) while simultaneously increasing pore water alkalinity. When coupled with wave loading, this biogeochemical process is a viable mechanism to produce voids and subsequently precipitate carbonate minerals. The disappearance of molar tooth structures in the mid-Neoproterozoic is likely linked to a combination of a decrease in smectite abundance, a decline in the marine DIC reservoir, and an increase in the concentration of O2 in shallow seawater.

Hippocampus-dependent spatial memory impairment due to molar tooth loss is ameliorated by an enriched environment.

Science.gov (United States)

Kondo, Hiroko; Kurahashi, Minori; Mori, Daisuke; Iinuma, Mitsuo; Tamura, Yasuo; Mizutani, Kenmei; Shimpo, Kan; Sonoda, Shigeru; Azuma, Kagaku; Kubo, Kin-ya

2016-01-01

Teeth are crucial, not only for mastication, but for overall nutrition and general health, including cognitive function. Aged mice with chronic stress due to tooth loss exhibit impaired hippocampus-dependent learning and memory. Exposure to an enriched environment restores the reduced hippocampal function. Here, we explored the effects of an enriched environment on learning deficits and hippocampal morphologic changes in aged senescence-accelerated mouse strain P8 (SAMP8) mice with tooth loss. Eight-month-old male aged SAMP8 mice with molar intact or with molars removed were housed in either a standard environment or enriched environment for 3 weeks. The Morris water maze was performed for spatial memory test. The newborn cell proliferation, survival, and differentiation in the hippocampus were analyzed using 5-Bromodeoxyuridine (BrdU) immunohistochemical method. The hippocampal brain-derived neurotrophic factor (BDNF) levels were also measured. Mice with upper molars removed (molarless) exhibited a significant decline in the proliferation and survival of newborn cells in the dentate gyrus (DG) as well as in hippocampal BDNF levels. In addition, neuronal differentiation of newly generated cells was suppressed and hippocampus-dependent spatial memory was impaired. Exposure of molarless mice to an enriched environment attenuated the reductions in the hippocampal BDNF levels and neuronal differentiation, and partially improved the proliferation and survival of newborn cells, as well as the spatial memory ability. These findings indicated that an enriched environment could ameliorate the hippocampus-dependent spatial memory impairment induced by molar tooth loss. Copyright © 2015 Elsevier Ltd. All rights reserved.

Power Consumption Optimization in Tooth Gears Processing

Science.gov (United States)

Kanatnikov, N.; Harlamov, G.; Kanatnikova, P.; Pashmentova, A.

2018-01-01

The paper reviews the issue of optimization of technological process of tooth gears production of the power consumption criteria. The authors dwell on the indices used for cutting process estimation by the consumed energy criteria and their applicability in the analysis of the toothed wheel production process. The inventors proposed a method for optimization of power consumptions based on the spatial modeling of cutting pattern. The article is aimed at solving the problem of effective source management in order to achieve economical and ecological effect during the mechanical processing of toothed gears. The research was supported by Russian Science Foundation (project No. 17-79-10316).

Addressing Tooth Decay in Head Start Children

Science.gov (United States)

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

2012-01-01

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…

Relationship between natural tooth shade and skin colour.

Science.gov (United States)

Nourbakhsh, M; Mousavinejad, N; Adli, A R; Harati, M

2013-06-01

The purpose of this study was to assess the correlation of skin colour and tooth shade. One hundred and twenty six individuals aging between 18 to 25 years participated in this study. Colour of the maxillary central incisors was examined by VITA easy shade. Tooth shades were assigned to four ordinal values. Nivea Beauty Protect Foundation shade sample was used as a guide to assess facial skin colour Shin colours were also assigned to four ordinal values. Spearman test revealed that there was a significant relationship between tooth shade and skin colour Total co-relation factor was 51.6% (p men (p <0 .01). The highest tooth shade prevalence belonged to the second group and the highest skin colour prevalence was also in the second skin colour group.

Component Repair Times Obtained from MSPI Data

Energy Technology Data Exchange (ETDEWEB)

Eide, Steven A. [Curtiss-Wright/Scietech, Ketchum, ID (United States); Cadwallader, Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-05-01

Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only

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

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Rafael Scaf de Molon

2014-01-01

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

[Advantages and disadvantages of applying yttrium stabilized zirconium-dioxide post and core restorations].

Science.gov (United States)

Pétercsák, Anita; Radics, Tünde; Hegedus, Csaba

2014-03-01

Full ceramic restorations are associated with metal free post and core prosthodontics for teeth with seriously destroyed clinical crowns. Using custom made zirconium-dioxide post and cores can be flattering not only to give a good aesthetic result, but also to provide excellent retention. As none of the post systems stands all demands, prudent planning is mandatory. Our paper deals with favourable and unfavourable conditions as well as common causes of failures of post and core restorations. We took morphological, esthetical and functional considerations that can help to achieve the best results. Amongst them individual anatomic constitution, shape, width and length of the root and root canal, shape of the clinical crown, direction and magnitude of chewing forces are the most important factors. To give examples we present two cases of zirconium-dioxide post and core restorations. In our first case the missing clinical crown and a too wide root canal entrance created a questionable prognosis. To minimize adverse effect of the missing ferrule effect we applied custom-made zirconium-dioxide post and core and an additional abutment. After 7 years the restoration is still functioning. The second case represented a much favourable situation with 1,5 mm clinical crown height. The restoration was a custom-made zirconia post and core and a full-ceramic crown as a single tooth restoration. Although in this case we expected a better prognosis, 15 months later the patient showed up with a post fracture for applying extreme forces on the crown.

Power loss analysis in altered tooth-sum spur gearing

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Sachidananda H. K.

2018-01-01

Full Text Available The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing.

Caries experience of Egyptian adolescents: does the atraumatic restorative treatment approach offer a solution?

Science.gov (United States)

Mobarak, E H; Shabayek, M M; Mulder, J; Reda, A H; Frencken, J E

2011-01-01

To assess the prevalence and severity of dental caries amongst Egyptian adolescents and the prevalence of carious lesions treatable through the atraumatic restorative treatment (ART) approach. Using a convenient sample procedure, two secondary schools with a dental clinic were selected (967 students, average age: 13.7 ± 0.8 years, range: 12-15). Dental caries was diagnosed using the ART caries criteria, and plaque and calculus were assessed using the Green and Vermillion criteria amongst students grades 1-3 in the dental clinic by 3 calibrated examiners. The effect of the independent variables gender, age, tooth surface, jaw side (left or right) and type of jaw (mandible/maxilla) on dependent caries experience variables and D(2) and D(3) variables were tested using ANOVA. The prevalence of dental caries including enamel lesion (D(2)MFT) amongst the 967 students was 51.4% and that of dental caries excluding enamel lesions (D(3)MFT) was 38.1%. The mean D(2)MFT and D(3)MFT scores were 1.5 and 0.8, respectively. The percentage of teeth filled and extracted was low. Female students had statistically significantly higher mean D(3)MFT/S and D(2)MFT/S scores than males (p ART was 48% for score 2 and 28% for score 3. Most of the cavitated lesions were found untreated despite the presence of a dental clinic and a dentist on the school premises. The majority of cavitated lesions without pulp involvement could be treated using the preventive and restorative components of the ART approach. Copyright © 2011 S. Karger AG, Basel.

3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching

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Bryant Anthony Irawan

2015-01-01

Full Text Available This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n=30 measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n=10: subgroup A (Opalescence PF, subgroup B (Opalescence Boost in-office bleaching, and subgroup C (distilled water serving as control. Samples were bleached according to the manufacturer’s instructions for a period of two weeks. The Commission Internationale de L’Eclairage (CIE L*, a*, b* system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM. Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤0.05. The three restorative materials showed significant color changes (ΔE; P≤0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6 > Ketac Nano (2.97 ± 1.2 > Filtek Z350 XT (2.25 ± 1.0. However, none of the tested materials showed statistically significant changes in surface roughness; P>0.05.

Infrared light sensor applied to early detection of tooth decay

Science.gov (United States)

Benjumea, Eberto; Espitia, José; Díaz, Leonardo; Torres, Cesar

2017-08-01

The approach dentistry to dental care is gradually shifting to a model focused on early detection and oral-disease prevention; one of the most important methods of prevention of tooth decay is opportune diagnosis of decay and reconstruction. The present study aimed to introduce a procedure for early diagnosis of tooth decay and to compare result of experiment of this method with other common treatments. In this setup, a laser emitting infrared light is injected in core of one bifurcated fiber-optic and conduced to tooth surface and with the same bifurcated fiber the radiation reflected for the same tooth is collected and them conduced to surface of sensor that measures thermal and light frequencies to detect early signs of decay below a tooth surface, where demineralization is difficult to spot with x-ray technology. This device will can be used to diagnose tooth decay without any chemicals and rays such as high power lasers or X-rays.

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bracket adhesive resin and tooth conditioner. 872... SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a device...

Visualization of Tooth for Non-Destructive Evaluation from CT Images

Energy Technology Data Exchange (ETDEWEB)

Gao, Hui; Chae, Ok Sam [Kyung Hee University, Seoul (Korea, Republic of)

2009-06-15

This paper reports an effort to develop 3D tooth visualization system from CT sequence images as a part of the non-destructive evaluation suitable for the simulation of endodontics, orthodontics and other dental treatments. We focus on the segmentation and visualization for the individual tooth. In dental CT images teeth are touching the adjacent teeth or surrounded by the alveolar bones with similar intensity. We propose an improved level set method with shape prior to separate a tooth from other teeth as well as the alveolar bones. Reconstructed 3D model of individual tooth based on the segmentation results indicates that our technique is a very conducive tool for tooth visualization, evaluation and diagnosis. Some comparative visualization results validate the non-destructive function of our method.

Angulation change of the third molar tooth in orthodontic treatment

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Ardiansyah S. Pawinru

2017-04-01

Full Text Available Objective : Impaction of the third molar tooth mandibular is often found in patients with orthodontic treatment. In orthodontic treatment, extraction cases of impaction of the third molar tooth are usually performed, but the patients often refuse this extraction. Extraction of premolar has a good effect on the third molar mandibular angulation during treatment. Material and Methods : This study is a retrospective clinical study with descriptive analytic to find out the effect of the first mandibular premolar tooth extraction to angulation change of the third molar mandibular in orthodontic treatment with a standard edgewise method. Angulation change was performed by comparing the third molar mandibular angulation before and after orthodontic treatment with panoramic radiographs. Angulation of the third molar tooth mandibular was calculated from the angle formed between the long axis of the tooth with the reference line infraorbita. Results : The sample comprised 60 of impacted mandibular third molar region of the left and right regions of 30 patients who had been treated declared cured in clinic of orthodontic specialist of Dentistry Faculty Padjadjaran University. The sample was divided into three (3 groups of patients before treatment angulation of the third molar tooth mandibular under 300, 300 to 600 and above 60o, then measured change of angulation and observed whether it increased, fixed or decreased. Results were analyzed by T- test and Wilcoxon test showed that there was a significant change in angulation of the third molar mandibular in orthodontic treatment with the first premolar tooth mandibular extraction. Conclusion : This study is that the first premolar tooth mandibular extraction affects the angulation of the third molar tooth mandibular after orthodontic treatment.

Effect of Different Surface Treatments on the Bond Strength of Repaired Resin Restorations

International Nuclear Information System (INIS)

Engy Fahmy Ismaiel Fekry Abaza

2010-01-01

In the last decade, growing demands by patients for mercury-free esthetic restorations had markedly increased the use of resin composites in restorative dentistry. However, despite the continuing development of resin composites with improved properties, several factors, such as discoloration, color mismatch, wear; chipping or bulk fracture might present clinical problems (Mjor and Gordan. 2002, Vichi et al. 2004 and Kolbeck et al. 2006). As a result, the clinician should decide whether to replace or simply repair these restorations. Total replacement of the restoration might be regarded as over-treatment since in most cases, large portions of the restorations might be clinically and radio graphically considered free of failure. Moreover, complete removal of the restoration inevitably resulted in weakening of the tooth, unnecessary removal of intact dental tissues, more money and time consuming. For these reasons, the repair of the restoration instead of its removal would be a favorable procedure (Lucena-Martin et al. 2001, Frankenberger et al. 2003 a and Oztas et al. 2003). The key element in the determination of successful repair procedures was the adequate bond strength between the existing resin composite and the new one. Various methods have been suggested to improve the bond strength of the repaired resin restorations (Tezvergil et al. 2003 and Bonstein et al. 2005). Mechanical and/or chemical treatments had been investigated for preparation of the aged resin restorations to be repaired (Tezvergil et al. 2003, Ozcan et al. 2005 and Hannig et al. 2006). These treatments were introduced to counteract the problems of aged resin restorations which were limited amount of residual free radicals available for reaction with the repair material, contaminated surface, and highly cross-linked resin matrix ( Dall Oca et al. 2006 and Papacchini et al. 2007 a) Previous studies emphasized that mechanical treatments are the most important factor in obtaining optimal repair

The Importance of Tooth Decay Prevention in Children under Three

Science.gov (United States)

Milgrom, Peter; Huebner, Colleen; Chi, Donald

2010-01-01

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

Promoting positive health behaviours--'tooth worm' phenomenon and its implications.

Science.gov (United States)

Gao, X L; Hsu, C Y S; Xu, Y C; Loh, T; Koh, D; Hwarng, H B

2012-03-01

'Tooth worm' is a traditional belief about the pathogen of dental caries (tooth decay). Nevertheless, in our previous study, parental 'tooth worm' belief was linked to a reduced caries risk of their children. This study aimed to further characterize the impact of parental 'tooth worm' belief on their children's caries experience and its psychobehavioural mechanisms. analytic observational study. Thirteen randomly selected kindergartens in Singapore. 1,782 preschoolers aged 3-6 years. Each child received an oral examination and microbiological tests. Parents completed a self-administered questionnaire on their socio-demographic background, oral health knowledge/attitude and child's oral health habits. Multivariate analysis confirmed a reduced chance of 'high caries rate' (number of affected teeth > 2) among children whose parents held the 'tooth worm' belief (Odds Ratio = 0.41; 95% Confidence Interval = 0.19-0.89). With such perception among parents, children brushed their teeth more frequently (p = 0.042). Since no difference in oral hygiene was observed, the health benefit of the "tooth worm" perception may be acquired through the delivery of fluoride (an agent with proven anti-caries effect) during frequent toothbrushing episodes. This study revealed a 'tooth worm' phenomenon, indicating that parental 'tooth worm' belief is associated with early establishment of regular toothbrushing habit and reduction of dental caries in children. This phenomenon and its psychobehavioural mechanisms, enriching our understanding of oral health behaviours, have implications for effective health education.

Orthodontic Tooth Movement with Clear Aligners

OpenAIRE

Drake, Carl T.; McGorray, Susan P.; Dolce, Calogero; Nair, Madhu; Wheeler, Timothy T.

2012-01-01

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. ev...

Drugs influencing orthodontic tooth movement: An overall review

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Kamatchi Diravidamani

2012-01-01

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

Evaluation of effect of 3D video glasses on perceived pain and unpleasantness induced by restorative dental treatment

DEFF Research Database (Denmark)

Bentsen, Bo; Svensson, Peter; Wenzel, Ann

2001-01-01

whether distraction induced by video glasses also had an effect on the perceived intensity of pain and unpleasantness during dental treatment. Pain and unpleasantness was evoked by the preparation (drilling) of a minor dental cavity (class I). Twenty-three patients (17 female and six male, age range 20......-49 years) with a need for an occlusal dental restoration in two homologous teeth participated in the study, In this split-mouth design, the patient received the dental treatment wearing 3D video glasses and without video glasses (control situation) in a randomized order. The tooth cavities were prepared...... in accordance with conventional techniques after mounting the video glasses. The patient rated the intensity of pain and unpleasantness on 100 mm visual analogue scales (VASs) after preparation of the first cavity; immediately after, the opposite tooth was prepared and again the volunteer rated the intensity...

Replacing a Missing Tooth

Science.gov (United States)

... lateral incisor. This may be accomplished by adding plastic or porcelain filling material or a porcelain crown ... This type of bridge requires much less tooth reduction of adjacent teeth, and there is no danger ...

Line-Drawing Enhanced Interactive Mural Restoration for Dunhuang Mogao Grottoes

Science.gov (United States)

Fu, X. Y.; Han, Y.; Sun, Z. J.; Ma, X. J.; Xu, Y. Q.

2017-08-01

Dunhuang Mogao Grottoes in western China is one of the most famous World Cultural Heritage Sites, known for its glorious Chinese Buddhist art spanning a period of 1,000 years. However, it has been suffering from damage and degradation caused by man-made and natural factors. In this article, we present a novel line-drawing enhanced interactive system for digital restoration of damaged murals in Mogao Grottoes. Our system consists of four components, namely data pre-processing, damaged area selection, line-drawing segmentation, and mural restoration. Each component is a hybrid of efficient algorithms and user interactions. We introduce the infrastructure and process of using our system, from data capture and collection, database establishment, to interactive restoration. We conduct a user study with 15 participants who have varied experiences with and skills on repairing murals and editing images. Results and feedback suggest that our system can achieve satisfactory restoration results without overburdening the users. It can benefit both experts trained in restoration and amateurs interested in cultural heritage conservation.

Component Repair Times Obtained from MSPI Data

International Nuclear Information System (INIS)

Eide, Steven A.; Cadwallader, Lee

2015-01-01

Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a ''white'' (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant's insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of

Tooth eruption and browridge formation.

Science.gov (United States)

Russell, M D

1982-05-01

One of the most reasonable hypotheses regarding the functional significance of the browridge is that the supraorbital torus forms in response to masticatory stress during development. Oyen, Walker, and Rice (1979) have recently proposed a model that tests this hypothesis: if browridges are functionally related to masticatory stresses on the cranial vault, then changes in the biomechanics of the masticatory system ought to be reflected by changes in the browridge. To test their model they attempted to relate biomechanical discontinuities resulting from tooth eruption to episodes of bone deposition on the supraorbital tori of a developmental series of dry Papio crania. This paper reports on a parallel test of the model on a cross-sectional sample of Australian Aboriginal juvenile crania. This sample showed no relation between tooth eruption and the supraorbital surface morphology thought to be indicative of active bone deposition. It is also demonstrated that no significant relationship between tooth eruption and episodes of bone deposition is shown by the Papio sample. It is concluded that the use of small cross-sectional samples of dry crania does not provide a valid test of the model.

Cutaneous collateral axonal sprouting re-innervates the skin component and restores sensation of denervated Swine osteomyocutaneous alloflaps.

Directory of Open Access Journals (Sweden)

Zuhaib Ibrahim

Full Text Available Reconstructive transplantation such as extremity and face transplantation is a viable treatment option for select patients with devastating tissue loss. Sensorimotor recovery is a critical determinant of overall success of such transplants. Although motor function recovery has been extensively studied, mechanisms of sensory re-innervation are not well established. Recent clinical reports of face transplants confirm progressive sensory improvement even in cases where optimal repair of sensory nerves was not achieved. Two forms of sensory nerve regeneration are known. In regenerative sprouting, axonal outgrowth occurs from the transected nerve stump while in collateral sprouting, reinnervation of denervated tissue occurs through growth of uninjured axons into the denervated tissue. The latter mechanism may be more important in settings where transected sensory nerves cannot be re-apposed. In this study, denervated osteomyocutaneous alloflaps (hind- limb transplants from Major Histocompatibility Complex (MHC-defined MGH miniature swine were performed to specifically evaluate collateral axonal sprouting for cutaneous sensory re-innervation. The skin component of the flap was externalized and serial skin sections extending from native skin to the grafted flap were biopsied. In order to visualize regenerating axonal structures in the dermis and epidermis, 50 um frozen sections were immunostained against axonal and Schwann cell markers. In all alloflaps, collateral axonal sprouts from adjacent recipient skin extended into the denervated skin component along the dermal-epidermal junction from the periphery towards the center. On day 100 post-transplant, regenerating sprouts reached 0.5 cm into the flap centripetally. Eight months following transplant, epidermal fibers were visualized 1.5 cm from the margin (rate of regeneration 0.06 mm per day. All animals had pinprick sensation in the periphery of the transplanted skin within 3 months post

Potential ?Ecological Traps? of Restored Landscapes: Koalas Phascolarctos cinereus Re-Occupy a Rehabilitated Mine Site

OpenAIRE

Cristescu, Romane H.; Banks, Peter B.; Carrick, Frank N.; Fr?re, C?line

2013-01-01

With progressively increasing anthropogenic habitat disturbances, restoration of impacted landscapes is becoming a critical element of biodiversity conservation. Evaluation of success in restoration ecology rarely includes faunal components, usually only encompassing abiotic and floral components of the ecosystems. Even when fauna is explicitly included, it is usually only species presence/absence criteria that are considered. If restoration is to have a positive outcome, however, populations...

Difference in opalescence of restorative materials by the illuminant.

Science.gov (United States)

Yu, Bin; Lee, Yong-Keun

2009-08-01

To determine the differences in the opalescence parameter (OP) of indirect and direct resin composites, veneer ceramics and bovine enamel relative to the CIE standard illuminants D65, A and F2. BelleGlass NG (indirect resin; 10 shades) and Estelite Sigma (direct resin; 12 shades), and 4 shades of veneer ceramics were investigated. Bovine enamel was used as a reference. Reflected and transmitted colors of specimens were measured relative to the illuminants D65, A and F2 with a reflection spectrophotometer. OP values relative to the three illuminants [OP(D65), OP(A) and OP(F2)], difference in OP (DeltaOP) and OP difference ratio relative to OP(D65) [DeltaOP/OP(D65)] by the change of illuminants were calculated. Within each restorative material, DeltaOP and DeltaOP/OP(D65) values were analyzed with two-way analysis of variance (ANOVA), with the fixed factors of the shade designation and the combination of illuminants (alpha=0.05). DeltaOP and DeltaOP/OP(D65) values were influenced by the two factors within each restorative material based on two-way ANOVA. High opalescent materials showed higher DeltaOP values. OP(D65) was lower than OP(F2) and OP(A) values. Restorative materials showed lower DeltaOP/OP(D65) values than bovine enamel. Correlation coefficients between OP values relative to different illuminants were higher than 0.961 (Popalescence properties as compared with natural tooth enamel.

ISS protocol for EPR tooth dosimetry

International Nuclear Information System (INIS)

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

2000-01-01

The accuracy in Electron Paramagnetic 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 the framework of the European Community Nuclear Fission Safety project 'Dose Reconstruction' is presented. A combined mechanical-chemical procedure for ground enamel sample preparation is used. The signal intensity evaluation is carried out with powder spectra simulation program. Finally, the unknown dose is evaluated individually for each sample with the additive dose method. The unknown dose is obtained by subtracting a mean native dose from the back-extrapolated dose. As an example of the capability of the ISS protocol in unknown dose evaluation, the results obtained in the framework of the 2nd International Intercomparison on EPR tooth enamel dosimetry are reported

Quantitative assessment of the enamel machinability in tooth preparation with dental diamond burs.

Science.gov (United States)

Song, Xiao-Fei; Jin, Chen-Xin; Yin, Ling

2015-01-01

Enamel cutting using dental handpieces is a critical process in tooth preparation for dental restorations and treatment but the machinability of enamel is poorly understood. This paper reports on the first quantitative assessment of the enamel machinability using computer-assisted numerical control, high-speed data acquisition, and force sensing systems. The enamel machinability in terms of cutting forces, force ratio, cutting torque, cutting speed and specific cutting energy were characterized in relation to enamel surface orientation, specific material removal rate and diamond bur grit size. The results show that enamel surface orientation, specific material removal rate and diamond bur grit size critically affected the enamel cutting capability. Cutting buccal/lingual surfaces resulted in significantly higher tangential and normal forces, torques and specific energy (pmachinability for clinical dental practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

In Vitro Evaluation of the Effect of Tooth Structure Loss on Fracture Resistance of Endodontically Treated Teeth

Directory of Open Access Journals (Sweden)

Shirinzad M

2017-06-01

Full Text Available Introduction: Since preserving the structure of treated teeth is a critical success factor, studying the effects of tooth structure loss on fracture resistance of the tooth tissue appears necessary. The aim of this study was to evaluate the consequences of the loss of different tissues regarding fracture resistance of teeth undergoing root canal treatment without the use of indirect restorations. Methods :In this experimental study, 70 healthy maxillary first premolar teeth were randomly divided into 7 groups of 10 members, including control group, endodontic access preparation only, MOD cavity preparation, cutting buccal cusp, cutting palatal cusp, cutting buccal cusp and marginal ridge, and cutting the palatal cusp and marginal ridge. The coronal section of teeth was restored incrementally with light cure composite. Finally, samples underwent compressive load with 45˚ angle from each cusp slope in the middle of cusp with an instant speed of 1 mm per min in the Instron machine. Fracture resistance was measured and samples were examined under stereo-microscope to evaluate the mode of failure. Results: The resistance to fracture in root canal treated teeth in different groups in order from first to seventh was 797.13 ± 52.92, 722.50 ± 131.40, 432.15 ± 203.20, 592.66 ± 195.86 124.53 ± 33.09, 85.17 ± 18.45, and 26.03 ± 5.21 Newton. ANOVA test showed statistically significant differences between the groups in terms of their fracture resistance (P = 0.000. Conclusions: The results showed that fracture resistance levels of teeth were significantly affected by amount of their tissue loss. In this study, removal of teeth palatal cusp and marginal ridge had a significant effect on decreasing the fracture resistance, while removing the buccal cusps alone cannot have a significant effect.

Clinical research in implant dentistry: evaluation of implant-supported restorations, aesthetic and patient-reported outcomes.

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Lang, Niklaus P; Zitzmann, Nicola U

2012-02-01

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. © 2012 John Wiley & Sons A/S.

Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.

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M Aleksander Wysocki

Full Text Available Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month. Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo. Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.

Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.

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Wysocki, M Aleksander; Feranec, Robert S; Tseng, Zhijie Jack; Bjornsson, Christopher S

2015-01-01

Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.

Severe tooth wear in Prader-Willi syndrome. A case–control study

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Saeves Ronnaug

2012-05-01

Full Text Available Abstract Background Prader-Willi syndrome (PWS is a rare complex multsystemic genetic disorder characterized by severe neonatal hypotonia, endocrine disturbances, hyperphagia and obesity, mild mental retardation, learning disabilities, facial dysmorphology and oral abnormalities. The purpose of the present study was to explore the prevalence of tooth wear and possible risk factors in individuals with Prader-Willi syndrome. Methods Forty-nine individuals (6-40 years with PWS and an age- and sex-matched control group were included. Tooth wear was evaluated from dental casts and intraoral photographs and rated by four examiners using the Visual Erosion Dental Examination (VEDE scoring system and the individual tooth wear index IA. In accordance with the VEDE scoring system, tooth wear was also evaluated clinically. Whole saliva was collected. Results Mean VEDE score was 1.70 ± 1.44 in the PWS group and 0.46 ± 0.36 in the control group (p A was 7.50 (2.60-30.70 in the PWS group and 2.60 (0.90-4.70 among controls (p A; r = 0.82, p A; r = 0.43, p = 0.002. Tooth grinding was also associated with tooth wear in the PWS group, as indicated by the mean VEDE 2.67 ± 1.62 in grinders and 1.14 ± 0.97 in non-grinders (p = 0.001 and median IA values 25.70 (5.48-68.55 in grinders and 5.70 (1.60-9.10 in non-grinders (p = 0.003. Multivariate linear regression analysis was performed with tooth wear as the dependent variable and PWS (yes/no, age, tooth grinding and saliva secretion as independent variables. PWS (yes/no, age and tooth grinding retained a significant association with tooth wear, VEDE (p A (p  Conclusions Our study provides evidence that tooth wear, in terms of both erosion and attrition, is a severe problem in Prader-Willi syndrome. There is therefore considerable need for prosthodontic rehabilitation in young adults with PWS.

Tooth fragment reattachment techniques-A systematic review.

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Garcia, Fernanda Cristina P; Poubel, Déborah L N; Almeida, Júlio César F; Toledo, Isabela P; Poi, Wilson R; Guerra, Eliete N S; Rezende, Liliana V M L

2018-03-07

Several strategies have been developed for tooth fragment reattachment following fracture. Although many techniques have been reported, there is no consensus on which one has the best results in terms of the bond strength between the fragment and the dentin over time. The aim of this study was to assess the currently reported tooth fragment reattachment techniques for fractured crowns of anterior teeth. The PubMed, LILACS, Web of Science, Cochrane, and Scopus databases were searched in October 2016, and the search was updated in February 2017. A search of the gray literature was performed in Google Scholar and OpenGrey. Reference lists of eligible studies were cross-checked to identify additional studies; gray literature and ongoing trials were investigated. Two authors assessed studies to determine inclusion and undertook data extraction. Case reports/series of three or more cases, cross-sectional studies, cohort studies, and in vivo clinical trials in all languages were included. Five articles remained after screening. These studies predominantly reported on fragment reattachment with composite resin and resin cement. There was little consistency among the studies in regard to the technique used for tooth fragment reattachment and length of the follow-up period. According to the evidence found in the studies included in this review, simple tooth fragment reattachment was the preferred reattachment technique. An increase in the bond strength between tooth fragment and dentin was observed when an intermediate material was used. Further investigation is needed, using standard follow-up periods and larger samples. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of dental restorative materials on total antioxidant capacity and calcium concentration of unstimulated saliva.

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Ramezani, Gholam H; Moghadam, Mona-Momeni; Saghiri, Mohammad-Ali; Garcia-Godoy, Franklin; Asatourian, Armen; Aminsobhani, Mohsen; Scarbecz, Mark; Sheibani, Nader

2017-01-01

To evaluate the effect of dental amalgam and composite restorations on total antioxidant capacity (TAC) and calcium (Ca) ion concentration of unstimulated saliva. Forty-eight children aged 6-10 years selected and divided into three groups of sixteen (8 males, 8 females). In group A and B, samples consisted of two class II dental composite or amalgam restorations, while in group C samples were caries-free (control group). Unstimulated saliva from all samples was collected and TAC was measured by spectrophotometry using an adaptation of 2, 2'-azino-di-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) assay. The Ca ion level was estimated by an auto- analyzer. Data were analyzed with one- and two-way ANOVA test, at a p difference between groups ( p differences within and between groups ( p Gender is an effective factor in changes induced in oral cavity as females showed more emphatic reaction to dental filling materials than males. Patients who have dental restorations, especially dental composites, should pay more attention to their dental hygiene, because dental restorations can increase oxidative stress and decrease Ca ion level in saliva, which might jeopardize remineralization process of tooth structures after demineralization. Key words: Amalgam, caries, composite, saliva, total antioxidant capacity.

Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

International Nuclear Information System (INIS)

Khan, Rao F.H.

2003-01-01

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

Relationship between food habits and tooth erosion occurrence in Malaysian University students.

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Manaf, Zahara Abdul; Lee, Mei Tee; Ali, Nor Hazirah Muhammad; Samynathan, Selvamary; Jie, Ying Phor; Ismail, Noor Hasnani; Bibiana Hui Ying, Yong; Wei Seng, Yeo; Yahya, Nurul Asyikin

2012-04-01

Tooth erosion is a growing dental problem; however, the role of diet in the aetiology of tooth erosion is unclear. A cross-sectional study was conducted to determine the association between tooth erosion occurrence and the consumption of acidic foods and drinks among undergraduate university students. A total of 150 undergraduate students (33 males and 117 females) aged 19 to 24 years at Universiti Kebangsaan Malaysia participated in this study. The Basic Erosive Wear Examination was used to assess the occurrence of tooth erosion. Information regarding dental hygiene practices, usual dietary habits, and consumption of acidic foods and drinks was obtained through a structured questionnaire. In all, 68% of subjects had tooth erosion. Subjects who reported having received information about healthy eating were less likely to have tooth erosion (χ(2) [1, N = 150] = 7.328, P = 0.007). The frequencies of milk (OR = 0.29, 95% CI = 0.13-0.67) and tea/coffee (adjusted OR = 0.42, 95% CI = 0.19-0.95) consumption were negatively associated with tooth erosion. Dental hygiene practice, the frequency and amount of acidic food and drink intake, and body mass index classification were not significantly associated with the risk of tooth erosion (P > 0.05). A high prevalence of tooth erosion was observed among this group of students. Preventive measures, such as dietary advice and increased consumption of milk at a younger age, may reduce the occurrence of tooth erosion among this age group.