Clinical application of lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture in the restoration of single anterior tooth loss / 口腔疾病防治

Objective@#To investigate the clinical effect of lithium disilicate glass ceramic cantilever resin-bonded fixed partial dentures (CRBFPDs) on single anterior tooth loss to provide a reference for the selection of restoration methods for single anterior tooth loss.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Forty-two patients with less than two anterior teeth with monomaxillary loss were included in this study. After 6 months, 1 year, 2 years, and 3 years, the aesthetic and functional effects of the restorations and the periodontal health status were evaluated, and the visual analog scale (VAS) was used to assess patient satisfaction.@*Results@#During the observation period, the connector fractured in one case within 3 months. One case had debonded within 2 years. The aesthetic restoration effect of all lithium disilicate glass ceramic CRBFPDs was categorized as Class A. The periodontal health was good, there was no clinical absorption in the soft and hard tissues of the abutment or subbridge, periodontal status according to the evaluation indices was classified as class A, and the total satisfaction rate of the patient was 100%.@*Conclusion@#For single anterior tooth loss patients, lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture can achieve the restoration effect of less invasion, better adhesion, aesthetics, comfort and good biocompatibility. With high patient satisfaction, it can be considered an ideal restoration method for replacing a single anterior tooth.

Invitro Comparative Analysis of the Flexural Strength of 4 Different Commercially Available Provisional Materials Used in Fixed Partial Dentures – An Original Research

Background: Provisional Prosthesis in fixed partial dentures are subjected to Flexure under stress. Selection of appropriate material for fabrication of Provisional is of utmost importance as the Provisional prosthesis has to remain in function till definitive prosthesis is delivered. Material & Methods: Bar type specimens of four different commercially available brands for provisional restorations fabricated according to ADA specification No. 27 and immersed in artificial saliva. The specimens were fractured under 3-point loading test. Results: The flexural strength ranged between 60 to 110 Mpa. BisGMA Auto polymerizing composite resin from Dentsply Caulk shows the highest flexural strength. Conclusion: Within the limitations of this study, the flexural strengths were material specific rather than category one. The BisGMA composite based resin shows significantly higher flexural strength over other materials

The importance of properly distributing the occlusal load for the correct biomechanics of implant-supported fixed partial dentures: stress analysis in implants, prosthetic components and infrastructures / A importância da distribuição da carga oclusal de forma adequada para a correta biomecânica de prótese parcial fixa implantosuportada: análise das tensões em implantes, componentes protéticos e infraestruturas

ABSTRACT Objective: The present study analyzed the biomechanical behavior of the generated stress on the external surface of the rehabilitation elements (implants, components and infrastructures) according to different occlusion patterns on a fixed partial denture on osseointegrated implants. Method: The experimental groups varied according to the location of the occlusal load applied to the Fixed partial denture, with a total occlusal load of 750N in all groups, opting for greater loads on the occlusal table of the molar in relation to the premolar. This evaluation was performed by the finite element method with simulations by the AnsysWorkbench 16.0 Software program. Results: The results analyzed for implants and their components showed that the more posterior the occlusal loading, the greater the stress developed (group 4), always in the connection area between the prosthetic component and the implant, as this location can induce greater screw loosening. The results analyzed for the infrastructures showed that the most distributed occlusal loading possible (group 1) is the best situation for generating less stress. However, even in group 3 which obtained the highest stresses in the critical area of the prosthetic connection, the zirconia flexural strength values generated were not worrisome. Conclusion: It can be concluded that the occlusal adjustment of Fixed partial dentures are preponderant and decisive factors for correct biomechanics and preservation of the system in the long term in order to avoid possible damage and/or failures, and exert significant and notorious differences in the behavior of all structures studied herein.

RESUMO Objetivo: O presente estudo analisou o comportamento biomecânico do estresse gerado na superfície externa dos elementos reabilitadores (implantes, componentes e infraestruturas) de acordo com diferentes padrões de oclusão em uma prótese parcial fixa sobre implantes osseointegrados. Métodos: Os grupos experimentais variaram de acordo com a localização da carga oclusal aplicada na Prótese Parcial Fixa, com carga oclusal total de 750N em todos os grupos, optando por cargas maiores na mesa oclusal do molar em relação ao pré-molar. Esta avaliação foi realizada pelo método dos elementos finitos com simulações pelo programa AnsysWorkbench 16.0 Software. Resultados: Os resultados analisados para os implantes e seus componentes mostraram que quanto mais posterior a carga oclusal, maior a tensão desenvolvida (grupo 4), sempre na área de conexão entre o componente protético e o implante, pois este local pode induzir maior soltura do parafuso. Os resultados analisados para as infraestruturas mostraram que a carga oclusal mais distribuída possível (grupo 1) é a melhor situação para gerar menos estresse. No entanto, mesmo no grupo 3 que obteve as maiores tensões na área crítica da conexão protética, os valores de resistência à flexão da zircônia gerados não foram preocupantes. Conclusões: Pode-se concluir que o ajuste oclusal das Próteses Parciais Fixas são fatores preponderantes e decisivos para correta biomecânica e preservação do sistema a longo prazo a fim de evitar possíveis danos e/ou falhas, e exercem diferenças significativas e notórias no comportamento de todas as estruturas aqui estudadas.

Ectodermal Dysplasia in Primary Dentition – A Rare Case Report

Development of the primary and permanent dentition is a complex process wherein there is series of interactions between the ectoderm and ectomesenchyme. A cascade of signaling pathways occur in a spatio-temporal manner resulting in the development and eruption of the human dentition. Any developmental aberrations in shape, size, number, and position can lead to deviations from normal development of teeth. In this book, dental anomalies including gemination, fusion, concrescence, dilaceration, dens invaginatus, DE, taurodontism, enamel pearls, fluorosis, peg?shaped laterals, dentinal dysplasia, regional odontodysplasia and hypodontia etc. are discussed. Diagnosing dental abnormality needs a thorough evaluation of the patient and careful clinical and radiographical examination is required. Furthermore, more complex cases need multidisciplinary planning and treatment.

Residual stress estimated by nanoindentation in pontics and abutments of veneered zirconia fixed dental prostheses

Abstract Glass ceramics' fractures in zirconia fixed dental prosthesis (FDP) remains a clinical challenge since it has higher fracture rates than the gold standard, metal ceramic FDP. Nanoindentation has been shown a reliable tool to determine residual stress of ceramic systems, which can ultimately correlate to failure-proneness. Objectives: To assess residual tensile stress using nanoindentation in veneered three-unit zirconia FDPs at different surfaces of pontics and abutments. Methodology: Three composite resin replicas of the maxillary first premolar and crown-prepared abutment first molar were made to obtain three-unit FDPs. The FDPs were veneered with glass ceramic containing fluorapatite crystals and resin cemented on the replicas, embedded in epoxy resin, sectioned, and polished. Each specimen was subjected to nanoindentation in the following regions of interest: 1) Mesial premolar abutment (MPMa); 2) Distal premolar abutment (DPMa); 3) Buccal premolar abutment (BPMa); 4) Lingual premolar abutment (LPMa); 5) Mesial premolar pontic (MPMp); 6) Distal premolar pontic (DPMp); 7) Buccal premolar pontic (BPMp); 8) Lingual premolar pontic (LPMp); 9) Mesial molar abutment (MMa); 10) Distal molar abutment (DMa); 11) Buccal molar abutment (BMa); and 12) Lingual molar abutment (LMa). Data were assessed using Linear Mixed Model and Least Significant Difference (95%) tests. Results: Pontics had significantly higher hardness values than premolar (p=0.001) and molar (p=0.007) abutments, suggesting lower residual stress levels. Marginal ridges yielded higher hardness values for connectors (DPMa, MMa, MPMp and DPMp) than for outer proximal surfaces of abutments (MPMa and DMa). The mesial marginal ridge of the premolar abutment (MPMa) had the lowest hardness values, suggesting higher residual stress concentration. Conclusions: Residual stress in three-unit FDPs was lower in pontics than in abutments. The outer proximal surfaces of the abutments had the highest residual stress concentration.

Restorative Management of A Patient With Pronounced Gag Reflex: A Case Report

@#Patients with hyperactive gag reflexes pose challenges when undergoing routine dental procedures, and this can create difficulties in their treatment. The subsequent issues that dentists face in executing the proposed treatment plan could hinder optimal patient care and reduce the overall success of the treatment. The clinician should be skilled in diagnosing as well as competent when managing the care of patients presenting with a hyperactive gag reflex. This paper discusses a technique utilizing telescopic copings and a long-span fixed partial denture as an alternative to fixed implant restoration on a patient with a pronounced gag reflex.

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

Perceptions of rehabilitated patients with fixed partial dentures as to the temporary restoration

ABSTRACT: This study evaluated patients' perceptions regarding the installation of temporary fixed partial denture (TFPD). A questionnaire developed that addressed patients' perceptions about the temporary restorations, applied to patients after concluded their treatment. Responses were analyzed by descriptive statistics and contingency tables were constructed to statistically analyze the relationship between patients' perceptions of age, gender and type of prosthesis. We interviewed 28 patients (23 female; 5 male). In the results, 53.57% of the patients reported improvement in the chewing, 3.57% of the patients reported an improvement in speech, 21.43% of patients reported improvement in both aspects and another 21.43% of patients did not report functional improvements in speech and in chewing. Regarding dental pain, 89.28% did not present. In the hygienization aspect, 46.42% of the patients had difficulty, and 25% of the patients had bleeding gum. Finally, 89.28% of the patients reported that a TFPD made it possible to predict the final treatment outcome. No statistically significant difference was found when age (p = 0.86062) and gender (p=0.41225) were correlated. However, the type of prosthesis influenced patients' perceptions of TFPDs (p = 0.01254). It is concluded that TFPD is an important step in the treatment with fixed prosthesis.

Occlusion in implant- At a glance

Objectives: Occlusion is a critical and very important component for the clinical success and longevity of dental implants. This review article focuses on the various aspects of implant protective occlusion. Our scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. Materials and methods: A search strategy was performed in MEDLINE/PubMed, Scopus and Google Scholar with keywords ­ 'implants' and 'occlusion', 'implants' and 'fixed prosthesis, 'implants' and 'fixed dental prostheses', 'implants' and 'partial edentulism', 'implants' and 'complications', 'implants' and 'failures', 'implants' and 'cantilever', 'implants' and 'occlusal load'. Results: 135 articles were retrieved. After hand search a total of 290 articles were identified. Ultimately, 30 articles were selected and summarized and discussed as they met the selection criteria. Conclusion: Most of the available clinical data are controversial. Implant-protected occlusion can be accomplished by decreasing the width of the occlusal table and improving the direction of force. By doing these things, we can minimize overload on bone-implant interfaces and implant prostheses, to maintain an implant load within the physiological limits of individualized occlusion, and ultimately provide long-term stability of implants and implant prostheses. Current clinical practices rely heavily on principles extracted from the natural dentition or removable dental prostheses on complete edentulous patients and on expert opinions.

Resin Template for Guiding Preparation in Resin Bonded Fixed Partial Denture – A Case Report

@#Resin Bonded Fixed Partial Denture (RBPFD) is a popular treatment for tooth preservation. Mechanical retention is a problem for RBFPD, where debonding is the main cause of failure. RBFPD preparation is minimal invasive. It removes undercut and tooth structure that supports retention so that single insertion guide can be achieved. This preparation was achieved by using surveyor on diagnostic cast, but there was a concern how to copy the surveyed cast to intraoral. Resin template method as a preparation guide was useful to avoid excessive tooth removal. RBFPD design was marked by using pencil on the diagnostic cast. The cast was surveyed to get the preparation designed and prepared by using milling device surveyor and burs. The template was made on the cast. Separator was applied and resin template was built along the margin until the occlusal line angle. The abutment teeth were etched and bonded. Bonding procedure was done on template. The template was placed on the teeth and polimerized. Abutment teeth preparation were done according to the cast with the bur contact simultaneously with the template’s margin and finishing line. Resin template has better accuration and adaptation, easier made and efficient, also prevent excessive tooth removal and control the preparation, mechanical retention can be achieved for RBFPD restoration longevity. Resin template is useful because preparation can be transfered from diagnostic cast to intraoral accurately.

Application of single-retainer all-ceramic resin-bonded fixed partial denture in the maintenance of missing incisor gap after orthodontic treatment in adolescents: a case report / 华西口腔医学杂志

This article reports a case of an orthodontic adolescent patient without a right inferior incisor. The right lower canine was used as the abutment. The single-retainer all-ceramic resin-bonded fixed partial denture was used to restore the complete dentition. Thus, the missing space was filled, and the function and aesthetics were restored.

Evaluation of mechanical properties of CAD/CAM ceramic systems: literature review / Avaliação das propriedades mecânicas dos sistemas cerâmicos CAD/CAM: revisão de literatura

ABSTRACT Computer aided design / computer aided manufacturing (CAD/CAM) systems are among the most technological advanced techniques in oral rehab today. Compared with conventional techniques, they can optimize the resistance and the adaptation of dental ceramics. Thus, their indications of use have been widened, making the technique more and more well-known and widespread. Therefore, the aim of this study is to present a literature review on comparative studies of the mechanical properties of ceramic systems produced by CAD / CAM. A search for scientific articles published between 2009 and 2019, in English, Spanish or Portuguese, was performed through the databases SCIELO, BIREME and PUBMED, using the descriptors "Ceramics", "Computer Aided Design" and " Partial Fixed Prosthesis ". Currently, all ceramic systems appear to have adequate strength for simple rehabilitations, but ceramic restorations produced by CAD/CAM systems present greater reliability than other manufacturing methods, presenting a wider array of indications due to their higher mechanical resistance. These systems, besides their versatility, also present an excellent aesthetic result, guaranteeing appropriate optical properties such as translucency and fluorescence, similar to natural teeth. Although the cost is a limiting factor, CAD/CAM technology is in full development and with high success rates that qualifies it as the state of art in oral rehabilitation.

RESUMO O sistema CAD-CAM (computer aided design/computer aided manufacturing), que significa desenho auxiliado por computação e manufatura auxiliada por computação, é um dos recursos mais tecnológicos e modernos na reabilitação oral atualmente. É uma alternativa que otimizou a resistência e a adaptação das cerâmicas odontológicas. Dessa maneira, suas indicações de uso têm-se ampliadas, tornando-o cada vez mais conhecido e difundido. O objetivo deste estudo é apresentar uma revisão da literatura sobre estudos comparativos das propriedades mecânicas dos sistemas cerâmicos produzidos por CAD/CAM. Foi realizada a busca de artigos científicos publicados entre 2009 e 2019, em inglês, espanhol ou português, nas bases de dados SCIELO, BIREME e PUBMED, utilizando os descritores: "Ceramics", "Computer Aided Design" e "Prótese Parcial Fixa". Atualmente todos os sistemas cerâmicos parecem ter uma adequada resistência para reabilitações simples, mas as restaurações cerâmicas produzidas por sistemas CAD/CAM apresentam maior confiabilidade do que outros métodos de fabricação; apresentando maiores possibilidades de indicações devido aos seus maiores valores de resistência mecânica. Esta tecnologia embora apresente o custo como um fator limitante, está em pleno desenvolvimento e já apresenta propriedades mecânicas suficientes e com índices de sucesso que a qualificam como o estado da arte em reabilitação oral.

Awareness among Patients of Jammu Regarding Dental Implants as Treatment Option for Replacement of Missing Teeth

Background: Dental implant has gained importance over the last few years. The higher success rate of dental implants with>95% survival in 5 years is considered a successful dental implant therapy. The present study was conducted to assessawareness among the population of Jammu regarding dental implants as a treatment option for missing teeth.Materials and Methods: The present study was conducted on 580 patients visiting the department for replacement of missingteeth. Patients were provided with a questionnaire and asked to respond to it.Results: Of 580 patients, males were 350 and females were 230. We found that 30% were aware of RPD as options for missingteeth, 25% of FPD, and 30% of dental implants and 15% all of the above options. The source of information regarding dentalimplants was friends in 0%, dentists in 70%, and social media in 20%; 80% were well informed regarding dental implants bythe dentist and 10% moderately well. Reason for opting for dental implants was high success rate in 65%, esthetics in 20%,and function in 15%, the reason for not opting for dental implants was cost in 55%, long treatment time in 30% and need forsurgery in 15%, 40% replied that everyone should opt for dental implants, 35% replied rich patients, and 25% replied, theyI do not know. About 60% replied that it demands special treatment and care, 20% replied no, and 20% replied that I do notknow. About 60% think that the main complication of dental implants was a failure, infection by 30%, and I do not know by10%. About 68% replied that they would recommend friends/family about dental implants, 12% replied no, and 20% I do notknow. Suggestion to make people aware of dental implants was dental education by camps by 18%, newspapers by 24%, anddental awareness by dentists by 58%.Conclusion: The authors found that patients had sufficient awareness regarding dental implants as a treatment option formissing teeth

Prevalencia e intensidad de sensibilidad posoperatoria durante el tratamiento de prótesis fija / Prevalence and intensity of postoperative hypersensitivity during fixed prosthodontic treatment

RESUMEN Introducción: Durante la realización de prótesis fijas, el paciente puede presentar sensibilidad posoperatoria. Se ha descrito en la literatura diferentes prevalencias de esta sensibilidad, las cuales varían ampliamente, entre 3 por ciento y 34 por ciento. Objetivo: Determinar la prevalencia e intensidad de sensibilidad posoperatoria en el tratamiento de prótesis fija sobre diente vital. Métodos: se realizó un estudio clínico piloto descriptivo. La muestra fue de 35 dientes tratados de 20 pacientes. Esta fue conformada por pacientes atendidos por alumnos del Centro Odontológico de la Universidad de Los Andes, a los cuales se les realizó un tratamiento en base a prótesis fija sobre diente vital, desde el mes de abril hasta octubre del año 2015. Se registró la sensibilidad durante el tratamiento por medio la escala visual análoga a través de un diario completado por el paciente y por la escala verbal numérica aplicada por el investigador en distintas etapas clínicas. Resultados: Se observó una prevalencia del 31,4 por ciento con una intensidad de 0,62 ± 0,49 según la escala visual análoga y de 0 según la escala verbal numérica. Conclusiones: la prevalencia de la sensibilidad posoperatoria se aproximó al rango más alto descrito en la literatura. La intensidad de la sensibilidad observada fue leve a imperceptible clínicamente(AU)

ABSTRACT Introduction: During fixed prosthodontic treatment, patients may present postoperative hypersensitivity. The prevalence rates contained in the literature on the topic range from a mere 3 percent to 34 percent. Objective: Determine the prevalence and intensity of postoperative hypersensitivity during fixed prosthodontic treatment of vital teeth. Methods: A pilot descriptive clinical study was conducted. The sample was 35 treated teeth from 20 patients. These patients had been treated by students from the Dental Center at the University of Los Andes, and had undergone fixed prosthodontic treatment on vital teeth from April to October 2015. Hypersensitivity during the treatment was recorded with the visual analog scale based on a diary kept by patients and on the verbal numerical rating scale as applied by the researcher at the various clinical stages. Results: Prevalence was 31.4 percent with an intensity of 0.62 ± 0.49 by the visual analog scale and of 0 by the verbal numerical rating scale. Conclusions: The prevalence of postoperative hypersensitivity approached the highest range described in the literature, whereas the intensity of hypersensitivity ranged from mild to clinically imperceptible(AU)

Awareness and Knowledge of Dental Implants as an Option for Replacing Missing Teeth: A Survey in Hyderabad, India

Introduction: Awareness among patients regarding use ofimplants is in need and for which effective and adequatecommunication is vital. Aims and Objectives: To gauge theawareness and knowledge regarding dental implants as anoption of treatment to replace missing teeth among patients inHyderabad, India.Material and Methods: A standardized self- explanatoryquestionnaire was prepared and distributed in five dentalclinics of Hyderabad. The questionnaires were handed tothe patients during their regular dental visits. A total of 450subjects were included in this survey.Results: We found that 62.5% (250) patients had someknowledge about dental implants. The main source ofinformation regarding dental implants was form their friendsand relatives (35%; 140 subjects) and dentists being thesecondary source for 30% (120) of the sample. The majorhindering factor that prevents patients from choosing implantswas cost effectiveness in 87.5% (350) of the cases.Conclusion: The awareness and knowledge about dentalimplants in the subjects were acceptable among a selectedsample of dental patients in Hyderabad, India. Still there is aneed for providing more general and accurate information tothe patients about this latest treatment modality

Comparison of Flexural Strength of Three-Dimensional Printed Three-Unit Provisional Fixed Dental Prostheses according to Build Directions

PURPOSE: The aim of this study was to compare the flexural strength of provisional fixed dental prostheses which was three-dimensional (3D) printed by several build directions. MATERIALS AND METHODS: A metal jig with two abutment teeth and pontic space in the middle was fabricated. This jig was scanned with a desktop scanner and provisional restoration was designed on dental computer-aided design program. On the preprocessing software, the build angles of the restorations were arranged at 0°, 30°, 45°, 60°, and 90° and support was added and resultant structure was sliced to a thickness of 100 µm. Processed restorations were printed with digital light processing type 3D printer using poly methyl meta acrylate-based resin. After washing and post-curing, compressive loading was applied at a speed of 1 mm/min on a metal jig fixed to a universal testing machine. The maximum pressure at which fracture occurred was measured. For the statistical analysis, build direction was set as the independent variable and fracture strength as the dependent variable. One-way analysis of variance and Tukey's post hoc analysis was conducted to compare fracture strength among groups (α=0.05). RESULT: The mean flexural strength of provisional restoration 3D printed with the build direction of 0° was 1,053±168 N; it was 1,183±188 N at 30°, 1,178±81 N at 45°, 1,166±133 N at 60°, and 949±170 N at 90°. The group with a build direction of 90° showed significantly lower flexural strength than other groups (P<0.05). The flexural strength was significantly higher when the build direction was 30° than when it was 90° (P<0.01). CONCLUSION: Among the build directions 0°, 30°, 45°, 60°, and 90° set for 3D printing of fixed dental prosthesis, an orientation of 30° is recommended as an effective build direction for 3D printing.

Restaurações cerâmicas multicamadas e monolíticas: uma revisão de literatura / Multilayered and monolithic ceramic restorations: a literature review

Objetivo: realizar uma revisão de literatura sobre materiais, técnicas de confecção, vantagens, desvantagens e limitações das restaurações cerâmicas multicamadas e monolíticas. Revisão de literatura: embora as cerâmicas odontológicas sejam utilizadas para confecção de restaurações dentárias indiretas, porque têm excelentes propriedades mecânicas e estéticas, são materiais susceptíveis à fratura sob forças oclusais. Para compensar essa fragilidade, restaurações multicamadas são confeccionadas associando um material mais resistente para a infraestrutura e a posterior aplicação de cerâmica para recobrimento estético. Porém, as restaurações multicamadas apresentam como desvantagem o possível lascamento da cerâmica de recobrimento. Essas falhas comprometem a restauração funcional e a estética, exigindo a substituição da peça protética em muitos casos. Sendo assim, devido à evolução de sistemas cerâmicos e técnicas de processamento, surgiram as restaurações cerâmicas monolíticas fabricadas com um único material, a fim de superar tal limitação. Nesse sentido, diferentes materiais e técnicas são apresentados na literatura para a confecção de restaurações cerâmicas monolíticas. Considerações finais: as restaurações multicamadas têm bom resultado estético, porém podem apresentar lascamento da cerâmica de recobrimento. Essa limitação é superada pelo uso de um único material para as restaurações monolíticas, mas o resultado estético pode ser limitado. De um modo geral, a literatura demonstra um bom comportamento clínico para as restaurações cerâmicas multicamadas e monolíticas, quando a técnica de confecção e o sistema cerâmico são bem indicados. (AU)

Objective: the aim of this study was to conduct a literature review about the materials, techniques, advantages, disadvantages and limitations of multilayer and monolitic ceramic restorations. Literature review: although dental ceramics have been used for fabrication of dental restorations due to its good esthetic and mechanical properties, it is a material prone to fracture under oclusal loading. To surpass such fragility, multilayer restorations are fabricated using a resistant framework material associated to esthetic veneering ceramic. However, multilayer restorations present risk to chipping of veneering ceramic. Those failures represent a functional and esthetic problem, leading to restoration replacement. So, the evolution of ceramic systems and techniques generated monolitic restorations using a single material. Several materials and techniques are presented in the literature for fabrication of monolitic ceramic restorations. Final considerations: multilayer restorations present good esthetic result but delamination of veneering ceramic can occur. Such limitation is solved using a single material in monolitic restorations, but esthetic result is limited. In general, literature shows appropriate clinical performance for both multilayer and monolitic ceramic restorations when technique and materials are well indicated. (AU)

Data collection about failures in fixed partial dentures: 1-year monitoring / Levantamento das falhas em prótese parcial fixa: acompanhamento de um ano

ABSTRACT Objective: The aim of this study was to evaluate the satisfaction of patients rehabilitated with fixed partial denture and the incidence of failures/clinical complications of prostheses after one year. Methods: The patients answered a questionnaire about the satisfaction degree with dental treatment performed and care maintenance for prosthesis conservation. Clinical and radiographic evaluations of the prosthesis were performed. Data were tabulated for descriptive analysis of the factors assessed, with calculation of absolute frequencies and percentages, and chi-square and Fisher's exact test.. Results: A total of 9.67% failures were found. The most common was the prosthesis loosening (57.14%), followed by ceramic fracture (28.57%), and abutment tooth fracture (14.29%). Biological failures were observed in 30.65%. The most common failure was gingival recession (52.00%), periodontal pocket (24.00%), support periodontal involvement (16.00%), and recurrent caries (4.00%). Radiographic examination showed that 70.97% of the total number evaluated had some kind of failure. There was statistically significant association between satisfaction degree and technical failure (p=0.04). Conclusion: Patients were satisfied after observation period of 1 year. The main failures detected were: crown cementation failure and ceramic fracture; gingival recession, periodontal pocket; manufacture and cementation of short intraradicular post with increased diameter and crown cervical misfit.

RESUMO Objetivo: O objetivo deste estudo foi avaliar a satisfação dos pacientes reabilitados com prótese parcial fixa e a incidência de falhas/complicações clínicas das próteses instaladas após um ano. Métodos: Os pacientes responderam um questionário abrangendo o grau de satisfação pelo tratamento odontológico efetuado e os cuidados de manutenção realizados para a conservação da prótese. Na sequência foi realizada avaliação clínica e radiográfica das próteses. Os dados obtidos foram tabulados para análise descritiva dos fatores avaliados com cálculo de frequência absoluta e percentual, e teste de Qui-quadrado e Fischer. Resultados: Foram encontradas 9,67% de falhas, sendo a mais comum a descimentação (soltura da prótese) (57,14%), seguida da fratura da cerâmica (28,57%), e um caso de fratura no dente pilar (14,29%). As falhas biológicas foram observadas em 30,65%. A falha mais comum foi a recessão gengival (52,00%), seguida por bolsa periodontal (24,00%), envolvimento periodonto de suporte (16,00%), e recidiva de cárie (4,00%). No exame radiográfico 70,97% do número total avaliado apresentaram algum tipo de falha. Houve associação estatisticamente significante entre grau de satisfação e falhas mecânicas (p=0,04). Conclusão: Os pacientes ficaram satisfeitos após um período de acompanhamento de 1 ano. As principais falhas detectadas foram: falha de cimentação da coroa e fratura da cerâmica; Recessão gengival, bolsa periodontal; confecção e cimentação de pino intraradicular curto, pino com diâmetro aumentado e desajuste cervical da coroa.

Influence of the amount of tooth surface preparation on the shear bond strength of zirconia cantilever single-retainer resin-bonded fixed partial denture

PURPOSE: Conventional resin-bonded fixed partial dentures (RBFPDs) are usually made with a two-retainer design. Unlike conventional RBFPDs, cantilever resin-bonded fixed partial dentures (Cantilever RBFPDs) are, for their part, made with a single-retainer design. The aim of this study was to compare the effect of tooth surface preparation on the bond strength of zirconia cantilever single-retainer RBFPDs. The objective is to evaluate the shear bond strength of these single-retainer RBFPDs bonded on 3 different amount of tooth surface preparation. MATERIALS AND METHODS: Thirty extracted bovine incisors were categorized to 3 groups (n=10), with different amounts of tooth surface preparations. Teeth were restored with single-retainer RBFPDs with different retainer surfaces: large retainer of 32 mm²; medium retainer of 22 mm²; no retainer and only a proximal connecting box of 12 mm². All RBFPDs were made of zirconia and were bonded using an adhesive system without adhesive capacity. Shear forces were applied to these restorations until debonding. RESULTS: Mean shear bond strength values for the groups I, II, and II were 2.39±0.53 MPa, 3.13±0.69 MPa, and 5.40±0.96 MPa, respectively. Statistical analyses were performed using a one-way ANOVA test with Bonferroni post-hoc test, at a significance level of 0.001. Failure modes were observed and showed a 100% adhesive fracture. CONCLUSION: It can be concluded that the preparation of large tooth surface preparation might be irrelevant. For zirconia single-retainer RBFPD, only the preparation of a proximal connecting box seems to be a reliable and minimally invasive approach. The differences are statistically significant.

Application of single-retainer all-ceramic resin-bonded fixed partial denture in replacing single anterior tooth / 华西口腔医学杂志

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.