Analysis of color stability and degree of conversion of different types of resin composites

Abstract Resin composites containing surface pre-reacted glass (S-PRG) have been introduced to reduce demineralization and improve remineralization of the tooth structure. However, water diffusion within the material is necessary for its action, which can impair its overall physicomechanical properties over time, including color stability. This study aimed to evaluate the color stability and related degree of conversion (DC) of four resin composites. Discs (6 x 4 mm, n = 5/group) of microhybrid (MH), nanofilled (NF), nanohybrid (NH), and S-PRG-based nanohybrid (S-PRG-NH) composites with two opacities (A2/A2E and A2O/A2D) were prepared. Color (CIELab and CIEDE2000) was evaluated with a spectrophotometer after aging in grape juice (2 x 10 min/10mL/7days). The DC was analyzed by using Fourier transform infrared spectroscopy before and after light-curing. Data were statistically analyzed by using two-way analysis of variance and post-hoc least significant difference tests (p<0.05). In the color stability analysis, the interaction between filler type and opacity was significant (CIELab, p = 0.0015; CIEDE2000, p = 0.0026). NH presented the highest color stability, which did not differ from that of MH. The greatest color alteration was observed for S-PRG-NH. S-PRG fillers also influenced DC (p < 0.05). The nanohybrid resin composite presented favorable overall performance, which is likely related to its more stable organic content. Notwithstanding the benefits of using S-PRG-based nanohybrid resins, mostly in aesthetic procedures, professionals should consider the susceptibility of such resins to color alteration, probably due to the water-based bioactive mechanism of action.

Can composite packaging and selective enamel etching affect the clinical behavior of bulk-fill composite resin in posterior restorations? 24-month results of a randomized clinical trial

Abstract Objectives This is a double-blind, split-mouth, randomized clinical study that aims to evaluate the influence of bulk-fill composite packaging presented in syringes (BSy) and capsules (BCa), and the effect of selective enamel etching (SEE) on the clinical performance of class I and II bulk-fill resin composite restorations after 24 months. Methodology A total of 295 class I or class II restorations were performed on 70 patients. One universal adhesive was applied in all restorations. SEE was used in 148 restorations and self-etching mode (SET) in 147 restorations. After the adhesive application, cavities were restored with Filtek Bulk-fill Posterior Restorative in syringes (BSy), Filtek One Bulk-fill in capsules (BCa), or Filtek Supreme Ultra in syringes with the incremental technique (In). All restorations were evaluated using the FDI criteria after one week and after six, 12, and 24 months. Kaplan-Meier survival analysis and Pearson's Chi-square test were used (α=0.05) for statistical analysis. Results After 24 months, 62 patients were evaluated and four restorations were lost due to fracture (one for SEEBSy, two for SEEIn, and one for SETIn). No significant differences in the fracture and retention rate were found between groups (p>0.05). SEE showed significantly fewer marginal adaptation defects than SET (p<0.05). BCa and BSy groups showed fewer marginal discrepancies compared to In (p<0.05). Restorations performed with BCa showed less color mismatch than BSy or In (p<0.05). Conclusion Although all restorations exhibited satisfactory clinical performance after 24 months of clinical service, the clinical behavior of class I and II restorations' improved when performed with a bulk-fill composite in capsules, mainly when associated with a universal adhesive applied with SEE.

Clinical performance of resin composite restorations placed by dental students: a retrospective, cross-sectional, and observational study

Aim: A retrospective, cross-sectional study was carried out to evaluate the performance of resin composite restorations placed by undergraduate dental students with 1 to 15 years of placement based on dental records. Methods: Four calibrated operators evaluated 498 restorations (anterior and posterior) of 120 patients according to Ryge's validated criteria (USPHS). Results: The criteria that showed the smallest changes between the types of failures were color matching, marginal discoloration and surface texture. Regarding the longevity, the surface texture showed an increase in the frequency of failures from the second time interval (3.1 to 6 years). Higher prevalence of failure was found in class II and III restorations, with secondary caries being the main reason. No significant differences were found for anatomic form, marginal adaptation, and color matching. Class V restorations showed a higher fracture rate with total displacement of the restoration, with no increase in the frequency of fracture over time. Conclusion: High rate of restoration failure was observed, possibly due to the lack of experience and skills of the students. This outcome highlight the need for continuous revision and improvements of teaching practice regarding the development of clinical competences and skills by dental students

Influence of abutment angulation on implant failure in immediately placed and restored implants in the esthetic zone: a randomized clinical trial

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective:Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results:There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants

Factores asociados a los fracasos de las rehabilitaciones protésicas en la Facultad de Estomatología de Villa Clara en los años 2016 - 2017 / Factors associated with failures of prosthetic rehabilitation in the Dentistry Faculty of Villa Clara during 2016-2017

RESUMEN Introducción: El porcentaje de repeticiones influye directamente en la calidad de un servicio, dado que esto afecta directamente la eficiencia. Objetivo: Identificar los posibles factores que influyen en el fracaso de las rehabilitaciones en los pacientes tratados en la Facultad de Estomatología de Villa Clara, entre los años 2016 y 2017. Métodos: Se realizó un estudio descriptivo, transversal en una población constituida por 694 pacientes. De estos resultaron 1112 casos. Las variables utilizadas fueron: tipo de fracaso, experiencia del licenciado, condiciones de trabajo, causas del fracaso, entre otras. Se utilizó como método la revisión documental y como instrumento, un formulario elaborado al efecto. Resultados: Se produjeron fracasos en 66 de los casos realizados (5,93%). Los principales factores influyentes fueron la experiencia del licenciado y las condiciones de trabajo; en el tipo de fracaso, los de laboratorio y entre las causas: los errores de enflascado, la falta de material, los principios biomecánicos y la relación céntrica defectuosa. Conclusiones: El índice de fracasos resultó alto, según los indicadores del Programa Nacional, aunque los casos de éxito superaron de forma notable a los fracasos.

ABSTRACT Introduction: the percentage of repetitions directly influences the quality of a service, given that this directly affects efficiency. Objective: to identify possible factors influencing the failure of rehabilitations in patients treated in the Dentistry Faculty of Villa Clara, between 2016 and 2017. Methods: a descriptive cross-sectional study was carried out in a population of 694 patients. A number of 1112 cases resulted. Type of failure, experience of the graduate, working conditions, causes of failure and others were the used variables. Documentary review was used as a method and a form was used as an instrument. Results: failures occurred in 66 of the analyzed cases (5.93%). The experience of the graduate and the working conditions were the main influential factors; laboratory failures were found in the type of failure, as well as errors were found in clamping, lack of material, biomechanical principles and defective centric relation among the causes of failures. Conclusions: the failure rate was high, according to the indicators of the National Programme, although the cases of success significantly outnumbered the failures.

Los fracasos de la rehabilitación protésica versus la eficiencia de los servicios / Failures of prosthetic rehabilitation versus efficiency of services

RESUMEN La cantidad de veces que hay que repetir un proceso influye directamente en su calidad, pues la repetición de las actividades afecta la eficiencia, aumenta los gastos y la insatisfacción del paciente debido al mayor tiempo utilizado para el tratamiento. Se realizó un estudio descriptivo y transversal, para identificar factores de influencia en el fracaso de las rehabilitaciones en los pacientes dados de alta en la Facultad de Estomatología de Villa Clara, en 2016 y 2017. En el 6,05 % de los pacientes se produjeron fracasos, lo que se tradujo en 5,93 % de casos repetidos. Los principales factores que influyeron fueron: la experiencia del licenciado, las condiciones de trabajo, y los fracasos de laboratorio; entre las causas de estos fracasos predominaron: los principios biomecánicos y la relación céntrica defectuosa. El índice de fracasos resultó alto según los indicadores del Programa Nacional, aunque los casos de éxito superaron de forma notable a los fracasos.

ABSTRACT The number of times a process has to be repeated has a direct influence on its quality, as repetition of activities affects efficiency, increases costs and patient dissatisfaction due to the longer time used for treatment. A cross-sectional descriptive study was carried out to identify factors influencing the failure of rehabilitations in patients discharged from the Dentistry Faculty of Villa Clara in 2016 and 2017. Failures occurred in 6.05% of the patients, resulting in 5.93% of repeated cases. The graduate experience, working conditions and laboratory failures were the main influencing factors; biomechanical principles and defective centric relation predominated among the causes of these failures. The failure rate was high according to the National Programme indicators, although the success rate significantly outweighed the failures.

Prevalence of unsatisfactory dental restorations in posterior primary teeth and associated factors

Abstract The aim of this study was to investigate the prevalence of unsatisfactory dental restorations on posterior primary teeth and associated factors in school children aged six to ten years. A cross-sectional study was conducted with children randomly selected from public schools in a small Brazilian town. Questionnaires were sent to the guardians addressing socioeconomic and behavioral aspects of the child. Oral examinations were performed at the schools to determine the quality of dental restorations, visible biofilm, and presence of moderate/extensive untreated caries (scores 3-6 ICDAS). This examination was performed by two previously trained and calibrated examiners. Associations were tested using multilevel logistic regression. Among the 400 children evaluated, 98 had restorations (217 teeth). The prevalence of unsatisfactory restorations was 34.6%. Restorations in amalgam were less likely to fail compared to those in glass ionomer cement (OR = 0.11; 95%CI: 0.02-0.49; p = 0.005). Children with moderate/extensive untreated caries were more likely to have unsatisfactory restorations (OR = 6.79; 95%CI: 2.20-20.93; p = 0.001). Children with a visible plaque index ≥ 20% were also more likely to have unsatisfactory restorations (OR = 2.28 95%CI: 1.05-4.92; p = 0.036). The prevalence of unsatisfactory restorations was high. The occurrence of this outcome was associated with restorative material, presence of caries, and visible plaque.

Influence of the FDI criteria in the restorations' evaluation and treatment decision in primary molars / Influência dos critérios da FDI na avaliação de restaurações e decisão de tratamento em molares decíduos

Objective: This study investigated the impact of FDI criteria for evaluating restorations on examiners' decision-making compared with their previous personal judgment in primary teeth. Secondly, the possible factors related to changes when using the criteria, including the examiners' experience were explored. Material and Methods: A cross-sectional study in a dental office setting was conducted selecting 27 resin composite restorations placed in primary molars in 11 children. Examinations of the restorations were performed by five undergraduate and five graduate dental students. First, the evaluations were performed based on personal judgment, and 2 weeks later, with FDI criteria. All examiners underwent training to use the FDI criteria after the first evaluation. The consensus of two benchmark examiners was considered to be the reference standard. Initially, a descriptive analysis was performed. Multiple Poisson regressions analyses were used to identify possible associated factors with outcomes - to be less or more invasive based on the FDI criteria than personal judgment. Results: The use of the FDI criteria changed the examiners' decisions in approximately 15% of the cases. Irrespective of examiners' experience, there was a trend of false results (compared to the reference examiners) when a change in the treatment decision was registered by using the FDI criteria. Examiners chose a less invasive option when assessing multi surface restorations with FDI criteria (PR=2.04, 95%CI=1.03-4.05; p=0.04). Examiners who spent more time for evaluation with FDI criteria were more invasive (PR=1.001, 95%CI=1.0001-1.002; p=0.03). Students were more invasive with the FDI criteria when examined children with higher dmf-t (PR=1.16, 95%CI=1.01-1.32; p=0.03). Conclusion: The use of the FDI criteria negatively influenced the restorations' evaluation and treatment decision in primary molars by undergraduate and graduate students.(AU)

Objetivo: Este estudo investigou o impacto dos critérios da FDI para avaliar restaurações na tomade de decisão feita pelos examinadores em comparação ao seu julgamento pessoal prévio em dentes decíduos. Secundariamente, foram explorados os possíveis fatores relacionados com mudanças causadas pelo uso dos critérios, incluindo a experiência dos examinadores. Material e Métodos: Um estudo transversal em ambiente de consultório odontológico foi conduzido selecionando 27 restaurações de resina composta realizado em molares decíduos em 11 crianças. As avaliações das restaurações foram realizadas por cinco estudantes de Graduação e cinco de Pós-graduação em Odontologia. As avaliações foram realizadas com base no julgamento pessoal e, duas semanas depois, com os critérios da FDI. Todos os examinadores foram treinados para utilizar os critérios da FDI após a primeira avaliação. O consenso de dois examinadores "padrão-ouro" foi considerado o padrão de referência. Inicialmente, uma análise descritiva foi realizada. Análises de regressão múltipla de Poisson foram utilizadas para identificar possíveis fatores associados com os desfechos ­ ser mais ou menos invasivo com o uso dos critérios da FDI em relação ao julgamento pessoal. Resultados: A utilização dos critérios do FDI alterou as decisões dos examinadores em aproximadamente 15% dos casos. Independente da experiência dos examinadores, houve uma tendência de resultados falsos (em comparação com os examinadores de referência) quando uma mudança na decisão de tratamento foi registrada usando os critérios da FDI. Os examinadores escolheram uma opção menos invasiva quando avaliaram restaurações envolvendo múltiplas superfícies com os critérios da FDI (RP = 2,04, IC 95% = 1,03-4,05; p = 0,04). Os examinadores que levaram mais tempo para avaliação das restaurações foram mais invasivos com o uso dos critérios da FDI (RP = 1,001, IC 95% = 1,0001-1,0002; p = 0,03). Os alunos foram mais invasivos com o uso dos critérios da FDI quando examinaram crianças com maior experiência de cárie (RP = 1,16, IC 95% = 1,01-1,32; p = 0,03). Conclusão: O uso dos critérios da FDI influenciou negativamente a avaliação das restaurações e decisão de tratamento em dentes decíduos realizada por estudantes de graduação e pós-graduação. (AU)

Biomechanical, operative and biological aspects of the cervical margin relocation: a case report / Aspectos biomecânicos, operatórios e biológicos da recolocação da margem cervical com resina composta em cavidades classe II com margens profundas: um relato de caso

The clinical success of tooth-colored indirect restorations has been confirmed in several studies. However, inlays and onlays restorations in Class II cavities with deep gingival margins can still be considered a clinical challenge. With the purpose of facilitating the execution of the operative procedures in intrasulcular margins and reducing the risk of restorative failures, the technique of cervical margin relocation has been explored as a noninvasive alternative to surgical crown lengthening. This work aims at discussing through a case report the biomechanical, operative and biological aspects in the treatment of teeth with deep gingival margins. Therefore, given the therapy applied in the clinical case presented, it is concluded that the cervical margin relocation with composite resin is advantageous since it eliminates the need for surgery, allowing the implementation of indirect restorations in fewer clinical sessions, not causing damage to periodontal tissues once it provided good finishing and polishing with the establishment of a correct emergence profile, allowing flawless maintenance of gingival health after one year. (AU)

Sucesso clínico das restaurações indiretas livres de metal tem sido confirmado em diversos estudos. No entanto, restaurações parciais indiretas em cavidades do tipo classe II com margens profundas ainda podem ser consideradas um desafio clínico. Com a proposta de facilitar a execução dos procedimentos operatórios em margens intra-sulculares e reduzir a ocorrência de falhas, a técnica de elevação da margem gengival em resina composta tem sido explorada como alternativa não invasiva à cirurgia de aumento de coroa clínica. Este trabalho tem a intenção de discutir através de um relato de caso clínico os aspectos biomecânicos, operatórios e biológicos no tratamento de dentes com margens cervicais profundas. Sendo assim, conclui-se que a técnica de elevação da margem gengival com resina composta é vantajosa, pois elimina a necessidade de cirurgia permitindo a execução de restaurações indiretas em menos sessões clínicas, não gerando danos aos tecidos periodontais, desde que haja um bom acabamento e polimento, com estabelecimento de um correto perfil de emergência. (AU)

Low- and high-viscosity bulk-fill resin composites / Resinas compostas bulk-fill de baixa e alta viscosidade

ABSTRACT The aim of this study was to compare low- and high-viscosity bulk-fill composites for Knoop microhardness (KHN), microtensile bond strength (MTBS) to dentin in occlusal cavities, and fracture strength (FS) in molars with mesialocclusal- distal restoration. Disk-shaped samples with different thicknesses (2 or 4 mm) of low-viscosity (SDR Flow, Dentsply) and high-viscosity bulk-fill composites (Filtek BulkFill, 3M ESPE; and Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) were prepared for top and bottom KHN analysis (n=10). MTBS to dentin and fracture pattern was evaluated in human molars with occlusal cavities restored with (n=10): conventional nanocomposite (Z350XT, 3M ESPE), low-viscosity (Filtek Bulk-fill Flow, 3M ESPE) or high-viscosity bulk-fill composites (Filtek BulkFill). The FS and fracture pattern of human molar with mesial-occlusal-distal restorations submitted or not to thermomechanical cycling were investigated (n=10) using: intact tooth (control), and restoration based on conventional microhybrid composite (Z250, 3M ESPE), low-viscosity (SDR Flow) or high-viscosity bulk-fill composites (Filtek BulkFill). The data were submitted to split-plot ANOVA (KHN), one-way ANOVA (MTBS), two-way ANOVA (FS) followed by Tukey's test (α=0.05). For KHN, there was no significant difference for the resin composites between the top and bottom. For MTBS, no significant differences among the materials were detected; however, the low-viscosity composite presented lower frequency of adhesive failures. For FS, there was no significant difference between composites and intact tooth regardless of thermomechanical cycling. Low- and high-viscosity bulk-fill composites have comparable microhardness and microtensile bond strength when used in occlusal restorations. Likewise, the bulk-fill composites present similar fracture strength in molars with mesio-occlusal-distal restorations.

RESUMO O objetivo deste estudo foi comparar resinas compostas bulk- -fill de baixa e alta viscosidade quanto à microdureza Knoop (KHN), resistência de união a microtração (MTBS) em cavidades oclusais e carga à fratura (FS) em molares com restauração mesio-oclusal-distal. Amostras em forma de disco com diferentes espessuras (2 ou 4 mm) de resinas bulk-fill de baixa viscosidade (SDR Flow, Dentsply) e alta viscosidade (Filtek BulkFill, 3M ESPE; e Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) foram obtidas para análise de KHN no topo e na base (n = 10). A MTBS em dentina e o padrão de fratura foram avaliados em molares humanos com cavidades oclusais restauradas com (n = 10): resina composta nanoparticulada convencional (Z350XT, 3M ESPE), resinas bulk-fill de baixa viscosidade (Filtek Bulk-fill Flow, 3M ESPE) ou alta viscosidade (Filtek BulkFill). Foram investigados a FS e o padrão de fratura de molares humanos em restaurações mesial-ocluso-distais sub metidas ou não à ciclagem termomecânica (n = 10), sendo: dente íntegro (controle), e restaurações baseadas em resina composta microhíbrida convencional (Z250, 3M ESPE); resinas bulk-fill de baixa viscosidade (SDR Flow) ou alta viscosidade (Filtek BulkFill). Os dados foram submetidos a split-plot ANOVA (KHN), one-way ANOVA (MTBS), two-way ANOVA (FS) seguidos do teste de Tukey (α = 0,05). Para KHN, não houve diferença significativa entre o topo e a base para as resinas compostas. Para MTBS, não foram detectadas diferenças significativas entre os materiais; entretanto, a resina bulk-fill de baixa viscosidade apresentou menor frequência de falhas adesivas. Para FS, não houve diferença significativa entre os materiais e o dente íntegro, independentemente da ciclagem termomecânica. As resinas bulk-fill de baixa e alta viscosidade têm microdureza e resistência à microtração comparáveis quando usados em restaurações oclusais. Da mesma forma, as resinas bulk-fill apresentam resistência à fratura semelhante em molares com restaurações mesio-oclusal-distais.

Recomendaciones sobre la reparación de restauraciones de amalgama / Recommendations about the repair of dental amalgam restorations

Introducción: La reparación de restauraciones de amalgama, los materiales, las caras de los dientes de preferencia para realizarlas y su controversia con la contraparte de realizar reemplazos, es algo que amerita atención por los investigadores para lograr definiciones y protocolos precisos. Objetivo: Sistematizar sobre las recomendaciones de la literatura con respecto a la reparación de restauraciones de amalgama. Métodos: Se realizó una revisión cualitativa. Se plantearon criterios de inclusión y exclusión para la selección de los artículos. La búsqueda se realizó en Scopus y Pubmed. De las investigaciones resultantes de la búsqueda fueron decantados los artículos que no coincidían con el problema de investigación en cuestión, luego los que no cumplían los criterios de inclusión y exclusión. Se realizó una evaluación de la calidad y validez de los artículos seleccionados para ser incluidos en esta investigación y, finalmente, se le dio lectura a los textos completos y resúmenes para extraer los datos necesarios para completar la base de datos de la investigación. Quedaron un total de 27 artículos que fueron tamizados en una base de datos Excel, la que luego se exportó al software SPSS para su procesamiento estadístico. Resultados: El 44,4 por ciento y 55,6 por ciento de los artículos recomiendan reparar las restauraciones con amalgama y resina compuesta, respectivamente. Casi la mitad de los artículos (48,1 por ciento) no precisaron una cara del diente susceptible o no para realizar reparaciones. El 44,4 por ciento concluyen con que es un tratamiento recomendable. Conclusiones: Es recomendable realizar reparaciones de restauraciones de amalgama con amalgama dental y con resina compuesta. No está claramente definido cuál cara del diente es susceptible o no a recibir reparaciones y es un tratamiento que puede formar parte del arsenal terapéutico de los odontólogos(AU)

Introduction: The repair of amalgam restorations, the materials used, the tooth sides preferred to perform them, and the controversy with the replacement option, are all topics deserving the attention of researchers with a view to achieving accurate definitions and protocols. Objective: Systematize the recommendations available in the literature about the repair of amalgam restorations. Methods: A qualitative review was carried out. Inclusion and exclusion criteria were established for the selection of papers. The search was conducted in Scopus and Pubmed. Papers not related to the research problem at hand were the first to be discarded. Then those not meeting the inclusion and exclusion criteria. An evaluation was performed of the quality and validity of the remaining papers, and finally their full texts and abstracts were read to retrieve the data required to complete the database of the study. The 27 papers thus obtained were sifted in an Excel database, which was then exported to the SPSS software for statistical processing. Results: 44.4 percent and 55.6 percent of the papers recommend to repair restorations with amalgam and composite resin, respectively. Almost half (48.1 percent) do not state any preference for a specific tooth side to perform the repair. 44.4 percent recommend the treatment. Conclusions: It is advisable to perform repairs of amalgam restorations with dental amalgam and with composite resin. It is not clearly defined which tooth side is preferred to undergo the repair. This treatment may be part of the therapeutic arsenal of dentists(AU)

Clinical Evaluation of Composite Resin Restorations in Posterior Teeth / Avaliação Clínica de Restaurações de Resina Composta em Dentes Posteriores

Factors such as aesthetics and adhesion to dental substrates have consolidated composite resin as a restorative material for posterior teeth, however, the performance is unsatisfactory regarding the longevity of these restorations. The purpose of this retrospective cross-sectional observational study was to evaluate the reasons that resulted in failure of class I and II Black composite resin restorations, performed by undergraduate dental students at the State University of Londrina. The patients were selected from the research of the medical charts filed at the University Dental Clinic's Screening Department. The restorations were evaluated by two calibrated dentists. The data collected were tabulated and analyzed using descriptive statistics, function Cont IF. Of the 261 class I and II restorations evaluated, 150 (57.5%) were in need of replacement. The main causes of failure of class I and II restorations were secondary caries (46.7%), followed by fracture (19.3%) and loss of marginal adaptation (16.7%). Of all the restorations made by the 3rd grade students, 68.4% failed, 57.4% performed by the 4th grade students and 53.9% of the 5th grade students. Based on the results, it is concluded that the main reasons for restorations failure were secondary caries, fracture and loss of marginal adaptation according to the evaluation criteria. Restorations performed by students in the 3rd grade showed a higher percentage of failures compared to those performed by students in the 4th and 5th grades. (AU)

Fatores como estética e adesão aos substratos dentários têm consolidado a resina composta como material restaurador para dentes posteriores, entretanto, o desempenho mostra-se insatisfatório em relação a longevidade destas restaurações. O objetivo desse estudo observacional transversal retrospectivo foi avaliar as razões que resultaram em falhas das restaurações de resina composta de classe I e II de Black, realizadas por alunos de graduação em Odontologia da Universidade Estadual de Londrina. Os pacientes foram selecionados a partir da pesquisa dos prontuários arquivados no Setor de Triagem da Clínica Odontológica Universitária. As restaurações foram avaliadas por dois avaliadores, cirurgiões-dentistas, calibrados. Os dados coletados foram tabulados e analisados por meio de estatística descritiva, função ContSE. Das 261 restaurações classes I e II avaliadas, 150 (57,5%) apresentavam-se com necessidade de substituição. As principais causas de falhas das restaurações classes I e II foram: cárie secundária (46,7%), seguido de fratura (19,3%) e perda de integridade marginal (16,7%). Dentre as restaurações realizadas por alunos da 3ª série e avaliadas, 68,4% falharam, da 4ª série 57,4% e da 5ª série 53,9%. Com base nos resultados, conclui-se que as principais razões de falha das restaurações foram cárie secundária, fratura e perda de integridade marginal, de acordo com os critérios de avaliação. As restaurações realizadas por alunos da 3ª série apresentaram maior percentual de falhas, comparadas as realizadas pelos alunos da 4ª e 5ª séries. (AU)

Resistencia a fractura de coronas elaboradas con disilicato de litio aplicadas en diferentes terminaciones marginales / Fracture resistance of crowns prepared with lithium disilicate applied to different marginal terminations

Resumen Evaluar la influencia del tipo de terminación marginal; filo de cuchillo (F) y chamfer (C) sobre la resistencia flexural de coronas de disilicato de litio CAD/CAM en espesores de 0,8 mm y 0,5 mm. Materiales y métodos: 40 premolares superiores sanos, en 2 grupos de acuerdo con el tipo de terminación G1=F y G2=C; 2 subgrupos referentes al espesor del material Sg1=0,8mm y Sg2 0,5 mm (5 coronas por cada subgrupo), se sometieron a fuerzas de compresión vertical (v) y horizontal (h). Se observó el tipo de fractura más frecuente; cohesivas en porcelana (cp), adhesiva en porcelana (ap), mixta pequeña (mp) y mixta larga (ml). Resultados: En preparaciones a 0,8 mm y 0,5 mm, existió diferencia significativa en relación con la mejor terminación, esta fue el C; sus valores fueron, Sg1 (h=1347,2 N / v=1402,0. F; Sg1 (h=965,6 N/ v= 794,8 N). F a 0,5 mm mostró mejor desempeño ante fuerzas horizontales. C; Sg2 (h=924,8 N /v=813,4 N) y para F; Sg2 (h=1217,0 N /v= 576,0 N). Conclusiones: Tipo de fractura más frecuente es cp y ap. Terminación chamfer y filo de cuchillo pueden ser utilizados con seguridad, pues muestran valores aceptables de resistencia flexural, al reducirse el grosor de la restauración en chamfer reduce su resistencia, el filo de cuchillo la aumenta.

Abstract Objective: To evaluate the influence of the type of shoulder margins; Knife edge (F) and Chamfer (C) on the flexural strength of CAD / CAM lithium disilicate crowns in thicknesses of 0.8 mm and 0.5 mm. Materials and Methods: 40 healthy upper premolars, in 2 groups according to the type of termination G1 = F and G2 = C; 2 subgroups referring to the material thickness Sg1 = 0.8mm and Sg2 0.5mm (5 crowns for each subgroup), were subjected to vertical (v) and horizontal (h) compression forces. The most frequent type of fracture was observed; cohesive in porcelain (cp), adhesive in porcelain (ap), mixed small (mp) and mixed long (ml). Results: In preparations with 0.8 mm and 0.5 mm thicknesses, there was a significant difference in relation to the best termination, this was C; their values were Sg1 (h = 1347.2 N / v = 1402.0.F; Sg1 (h = 965.6 N / v = 794.8 N) .F at 0.5 mm showed better performance against horizontal forces C; Sg2 (h = 924.8 N / v = 813.4 N) and for F; Sg2 (h = 1217.0 N / v = 576.0 N) Conclusions: The most frequent type of fracture is cp and ap finishing chamfer and knife edge can be used safely show acceptable values of flexural strength, by reducing the thickness of the chamfer restoration reduces its strength, the knife edge increases it.

Como reparar uma restauração oclusal de resina composta em dentes decíduos? Relato de caso / How to repair an occlusal composite resin restoration on primary teeth? Case report

Frente à necessidade de reintervenção em restaurações insatisfatórias, os clínicos podem, em geral, optar pela substituição ou reparo. Este artigo relata um caso clínico de reparo de uma restauração de resina composta com falha em dente decíduo. Após profilaxia e isolamento relativo, a porção da resina composta a ser reparada foi asperizada com uma ponta diamantada em alta rotação com o intuito de melhorar a união mecânica entre a resina envelhecida e a nova (reparo). Foi realizado o condicionamento com gel de ácido fosfórico a 34% por 15 segundos, seguido de lavagem e secagem. Uma camada do sistema adesivo Single Bond Universal (3M ESPE) foi aplicada ativamente durante 20 segundos, seguido de jato de ar comprimido por 5 segundos e fotoativação por 10 segundos. Por fim, a resina composta fluida (Filtek Z350 XT Flow; 3M ESPE) foi inserida e fotoativada por 20 segundos. A realização de um adequado protocolo clínico envolvendo tratamentos físicos e químicos de superfície é fundamental para a efetividade da intervenção e a manutenção do dente decíduo clinicamente funcional até a esfoliação fisiológica.

Facing need for reintervention in unsatisfactory resto-rations, clinicians may generally choose for replacement or repair. This paper reports a clinical case of repair of a composite resin restoration with failure in primary tooth. After prophylaxis and relative isolation, the portion of the composite resin to be repaired was roughed with a high-speed diamond bur to improve the mechanical bond between the aged and new resin (repair). Conditioning with 34% phosphoric acid gel was performed for 15 seconds, followed by washing and drying. One layer of the adhesive system Single Bond Universal (3M ESPE) was actively applied for 20 seconds and light- cured for 10 seconds. Finally, the flowable composite resin (Filtek Z350 XT Flow; 3M ESPE) was inserted and light-cured for 20 seconds. An adequate clinical protocol involving physical and chemical surface treatments is essential for the effectiveness of the intervention and the main-tenance of the primary tooth clinically functional until physiological exfoliation.

Influence of Vestibular Bevel on the Success of Traumatized Teeth Restorations: Single-Blind Randomized Controlled Trial - Preliminary Results with 6-Months Follow-Up

Abstract Objective: To evaluate the influence of cavosurface vestibular bevel (CSVB) application on the clinical success (CS) of class IV restorations of traumatized permanent teeth, the influence of the number of fracture angles and dental trauma recurrence (DTR) on the restorations retention rate (RRR) and incidence of pulp necrosis (PN). Material and Methods: Fifty-seven children and adolescents with enamel and dentin fractures requiring C-IV restorations were randomly allocated in groups with CSVB and without CSVB. The primary outcomes were the CS of restorations, evaluated using modified USPHS criteria, and the incidence of PN after a 6-months follow-up. As secondary outcomes, the influence of the number of fractured angles and the DTR on the RRR and on the incidence of PN were evaluated (p>0.05). Results: Of 57 children and adolescents, 74 teeth were restored, and 71 completed the six-month follow-up analysis. Teeth restored with and without CSVB displayed similar CS as well as the same incidence of PN (p>0.05). The number of fractured angles did not influence the RRR and DTR was not associated with PN (p>0.05). DTR was associated with a lower RRR (p<0.001). Conclusion: Cavosurface vestibular bevel did not influence the clinical success of Class IV restorations or incidence of PN after 6-months follow-up. DTR did not influence the incidence of pulp necrosis, but did negatively influence the restorations retention rate. The number of fracture angles did not influenced in the restorations retention rate.

Metal-ceramic partial fixed dentures: a retrospective study / Estudo retrospectivo de próteses parciais fixas metalocerâmicas

ABSTRACT Objective Metal-ceramic prosthesis are the treatment of choice in oral rehabilitation because of their high survival rates. However, there are few reports in the scientific literature about factors that lead to fractures of metal-ceramic prostheses. The aim of this study was to evaluate whether prostheses units number, abutment type and number, type of the prostheses, prostheses position in the mouth, bruxism and occlusal plaque influence the incidence of fractures in fixed metal-ceramic prostheses. Methods For this study, 16 patients were selected, totaling 74 metal-ceramic prostheses installed between 2000-2010, with follow up of at least four years. Besides dental history, other information was collected, such as patients' gender and age, prostheses installation date, and the ceramic system used. In case of prostheses fracture, a questionnaire was applied to identify signs of bruxism. A clinical evaluation was done to evaluate the prostheses integrity and opposing dentition characteristics. Success, failure and survival rates were determined. Results The results showed that the success rate of metal-ceramic prostheses was 87.8% and the survival rate was 89.1%. In addition, the success rate was independent of patient age, prostheses installation time, number of prosthesis, number of prosthesis' units and abutments. The qualitative variables also did not show significant statistical results between success and failure rates. Conclusion It was concluded that metal-ceramic prostheses have high success and survival rates, what guarantees longevity and indication of this type of prostheses in daily practice.

RESUMO Objetivo As próteses metalocerâmicas apresentam altas taxas de sobrevivência e, por isso, são indicadas para diversos casos em reabilitação oral. Entretanto, na literatura científica, existem poucos relatos clínicos sobre os fatores que levam à fratura dessas restaurações. Diante do exposto, o presente estudo teve como objetivo avaliar se a quantidade de elementos que compõem a prótese, se a quantidade de elementos por retentor, se o tipo de prótese e tipo de pilar, bem como sua localização, e o bruxismo, influenciam ou não nas fraturas dessas restaurações indiretas. Métodos Para isso, selecionaram-se 74 próteses metalocerâmicas, instaladas entre 2000 e 2010 em 16 pacientes, com acompanhamento mínimo de quatro anos. Foram coletadas informações dos pacientes, como: gênero, idade, data da instalação das próteses e cerâmica utilizada. Durante a avaliação clínica, observou-se a integridade da prótese e, em caso de fratura, coletava-se informações sobre a história clínica. As características do dente antagonista também foram avaliadas. Além disso, aplicou-se um questionário, com o intuito de identificar a provável presença de bruxismo. Resultados Como resultado, tem-se que a taxa de sucesso das próteses metalocerâmicas foi de 87,8% e, a taxa de sobrevivência, foi de 89,1%. A taxa de sucesso não teve influência da idade, tempo de instalação, número de próteses na boca, número de elementos ou pilares. Conclusão Embora pouco frequente, a fratura da cerâmica de cobertura foi a complicação mais comum. As próteses metalocerâmicas possuem altas taxas de sobrevida e de sucesso, o que garante a longevidade e a indicação desse tipo de restauração.

Efeito de tratamentos de superfície da resina, cimento resinoso e envelhecimento nas características interfaciais de restaurações semidiretas de resina composta / Effect of resin surface treatments, resin cement and aging on the interfacial characteristics of semi-direct composite resin restorations

A técnica semidireta realizada com resina composta pode ser uma excelente opção de tratamento para restaurações profundas e extensas em dentes posteriores devido às dificuldades técnicas no uso da resina composta pela técnica direta, como também pelos maiores custo e tempo de tratamento das restaurações indiretas com porcelana. O objetivo do estudo foi avaliar o efeito de diferentes tratamentos da superfície da restauração, tipos de cimento resinoso para cimentação e tempos de envelhecimento na durabilidade de união à dentina, padrão de falhas e nanoinfiltração de restaurações semidiretas. Foram utilizados 320 incisivos bovinos (N=320), dos quais foram obtidos discos de 4.0 mm de espessura e, na sua porção mais central, foi confeccionado um preparo cavitário cônico com 4.8 mm de diâmetro superior e 2.8 mm de diâmetro inferior. As amostras foram divididas em 16 grupos de acordo com o cimento resinoso: RelyX Ultimate (ULT) e RelyX U200 (U200); tratamento de superfície da resina: Silano (S), Single Bond Universal (SBU) e S+SBU; e tempo de envelhecimento: 24 horas (24h) e 6 meses (6m). As análises realizadas foram: Resistência de União à extrusão por push out (RU), Padrão de Falha (PF) e Nanoinfiltração (NI). Os dados foram analisados através de estatística descritiva e inferencial utilizando ANOVA Three Way com Post Hoc de Tukey (p<0,005). Para RU, ULT apresentou melhor desempenho em ambos os tempos de envelhecimento. SBU apresentou melhores resultados após 6 m quando associado ao ULT. As médias aumentaram com o tempo para o U200, exceto quando o silano foi utilizado como tratamento de superfície. Na análise do PF, o ULT apresentou o maior percentual de falha mista, quando a fratura ocorreu simultaneamente em dentina ou material restaurador e na interface adesiva, em ambos os tempos de envelhecimento e quando foi utilizado associado ao SBU ou ao S+SBU como tratamento de superfície da resina. Os diferentes tratamentos de superfície e tempos de envelhecimento não influenciaram a nanoinfiltração na interface cimento-resina. De acordo com os resultados encontrados nesse estudo laboratorial, observou-se um melhor desempenho para o ULT e entre os tratamentos de superfície, o uso de SBU possibilitou maior RU após 6 meses quando utilizado com esse cimento, porém não influenciou a nanoinfiltração na interface cimento-resina. Sugere-se que as restaurações semidiretas de resina composta podem ser cimentadas com ULT com SBU como tratamento de superfície da resina, como também com U200, sem a necessidade de nenhum tratamento químico na restauração (AU).

The semi-direct technique performed with composite resin can be an excellent treatment option for deep and extensive restorations on posterior teeth due to technical difficulties in the use of composite resin by the direct technique, as well as the higher cost and time of treatment of indirect restorations with porcelain. The aim of the study was to evaluate the effect of different treatments of the restoration surface, types of resin cement for cementation and aging times on the bond durability to dentin, failure pattern and nanoleakage of semi-direct restorations. 320 bovine incisors were used (N = 320), from which discs of 4.0 mm thickness were obtained and, in its most central portion, a conical cavity preparation with 4.8 mm in diameter and 2.8 mm in diameter was made. The samples were divided into 16 groups according to the resin cement: RelyX Ultimate (ULT) e RelyX U200 (U200); resin surface treatment: Silane (S), Single Bond Universal (SBU) and S+SBU; and aging time: 24 hours (24h) and 6 months (6m). The analyzes performed were: Bond Strength to push-out extrusion (BS), Failure Pattern (FP) and Nanoleakage (NL). The data were analyzed using descriptive and inferential statistics using ANOVA Three Way with Tukey's Post Hoc (p <0.005). For BS, ULT showed better performance in both times of aging. SBU showed better results after 6m when associated with ULT. The averages increased with time for U200, except when silane was used as a surface treatment. In the analysis of the FP, the ULT presented the highest percentage of mixed failure, when the fracture occurred simultaneously in dentin or restored material and at the adhesive interface, at both times of aging and when it was used in association with SBU or S + SBU as treatment resin surface. The different surface treatments and aging times did not influence nanoleakage at the cement-resin interface. According to the results found in this laboratory study, a better performance was observed for the ULT and among the surface treatments, the use of SBU enabled greater BS, however it did not influence the nanoleakage at the cement-resin interface. It is suggested that semi-direct composite resin restorations can be cemented with ULT with SBU as a resin surface treatment, as well as with U200, without the need for any chemical treatment in the restoration (AU).

Fracture resistance of extensive bulk-fill composite restorations after selective caries removal

Abstract This study evaluated the effect of selective carious tissue removal on the fracture strength and failure mode of composite restorations in molars presenting only the buccal cusps. Deep cavities were prepared on the occlusal surface, and the lingual cusps were removed. Carious lesions in the middle of the pulpal wall were artificially induced with acetic acid (pH = 4.5) for 35 days. The demineralized dentin was left intact or was completely removed prior to restoration with a bulk-fill composite (n = 10). Images of the specimens were obtained by optical coherence tomography (OCT) before and after the caries induction/removal. The mechanical resistance to fracture by axial compressive loading and the failure type and extension were determined. The pulpal wall/composite interface of the fractured specimens was analyzed by OCT. The data were analyzed for significance with t-tests (α = 0.05). The deepest cavities and a more frequent occurrence of pulpal exposure were observed more often for non-selective carious tissue removal. The protocol of carious tissue removal did not affect the fracture strength (p = 0.554). An increased occurrence of catastrophic failures involving the roots was observed for non-selective carious tissue removal. Some occurrences of restoration displacement or cracks throughout the resin-dentin were observed only for the selective carious tissue approach. Selective carious tissue removal is a feasible approach to extensively damaged teeth since it reduced the occurrence of pulpal exposure and root fractures, without compromising the fracture strength.

Choosing the Criteria for Clinical Evaluation of Composite Restorations: An Analysis of Impact on Reliabilty and Treatment Decision

Abstract Objective: To assess the reproducibility of two clinical criteria for the evaluation of restorations in primary teeth and the impact on treatment decision. Material and Methods: A cross-sectional study was performed selecting 71 resin-based composite restorations placed in primary molars of children who had sought dental treatment at a dental school. Two trained examiners evaluated independently the restorations using modified FDI and USPHS criteria. All restorations were assessed separately with each system in random order to avoid memory bias. Kappa statistics were used to determine inter-examiner reliability considering each parameter of both criteria and score final about treatment decision. McNemar test was used to compare the treatment decision with two criteria. The significance level was set at 5%. Results: Kappa values ranged from 0.28 to 0.93 with USPHS and 0.28 to 0.88 with FDI, considering each parameter separately. Inter-examiner agreement for treatment decision was excellent for both criteria (Kappa: 0.85-0.90). For clinical decision-making, no difference between criteria was found, irrespective of examiner. Conclusion: Low inter-examiner agreement for evaluation of each parameter of USPHS and FDI criteria does not reflect on reproducibility for treatment decision. Both criteria may be suitable for evaluation of composite restorations in primary teeth.

Survival, reasons for failure and clinical characteristics of anterior/posterior composites: 8-year findings

Abstract This retrospective study aimed to compare the annual failure rate (AFR), reasons for failure and factors influencing survival of posterior and anterior composite restorations placed by undergraduate students. Composite restorations placed by undergraduate students were evaluated. The restorations should be in occlusion, with at least one adjacent tooth; and patients should have been present for check-up, with at least 1 annual recall. The investigation was performed in two separate analysis: 1) dental electronic records of 100 patients (n=333 restorations) were selected to assess factors influencing survival; 2) clinical evaluation of 30 patients by examining restorations (n=123) to assess clinical characteristics and failure type distribution. Data were subjected to Kaplan-Meier method, Log-rank test, Cox regression and Fisher's Exact test (p<0.05). After 8-year period, the AFR was 2.62%. There was difference between anterior and posterior restorations (p=0.005), with anterior showing a higher AFR. The patient caries-risk (p<0.001) and the number of surfaces restored (p=0.010) affected restoration survival. The superficial brightness (p=0.029), fracture (p=0.025) and retention (p=0.011) were clinical criteria with differences between anterior and posterior restorations. Income (p<0.001), caries activity (p<0.001), caries risk (p<0.001) and oclusal risk (p<0.001) also influenced on the restorations survival. After 8-year, the AFR of restorations placed by undergraduate students was acceptable and affected by patient risk factors and the position of the tooth in the arch: anterior restorations failed more than posterior.

Resumo Este estudo retrospectivo comparou a taxa de falha anual (TFA), razões para falha e fatores influenciadores da sobrevida de restaurações posteriores e anteriores de resina composta realizadas por estudantes de graduação. As restaurações deveriam estar em oclusão, com pelo menos um dente adjacente, e os pacientes deveriam ter comparecido a pelo menos 1 consulta anual de retorno. A investigação foi realizada em 2 analises separadas: 1) dados odontológicos de prontuário eletrônico de pacientes (n=333 restaurações) foram selecionados para avaliar os fatores influenciadores na sobrevida; 2) avaliação de 30 pacientes por exame clinico das restaurações (n=123) para verificar as características clinicas e a distribuição do tipo de falha. Os dados foram submetidos a Kaplan-Meier método, Log-rank teste, regressão de Cox e Teste Exato de Fisher (p<0,05). Após o período de 8 anos, a TFA foi 2,62%. Houve diferença entre restaurações anteriores e posteriores (p=0,005), sendo que anteriores mostraram maior TFA. Os fatores de risco à carie (p<0,001) e o número de superfícies restauradas (p=0,010) influenciaram a sobrevida de restaurações. Brilho superficial (p=0,029), fratura (p=0,025) e retenção (p=0,011) foram critérios clínicos com diferenças entre restaurações anteriores e posteriores. Renda (p<0,001), atividade de cárie (p<0,001), risco à cárie (p<0,001) e risco oclusal (p<0,001) também influenciaram a sobrevida. Após 8 anos, a TFA das restaurações realizadas por estudantes de graduação foram clinicamente aceitáveis e afetadas pelos fatores de risco associados ao pacientes e a posição do dente na arcada; restaurações anteriores falham mais do que posteriores.