Insertion methods and gap/void formation in atraumatic restorative technique: A micro-CT analysis.

Wetting the dentin is critical to atraumatic restorative treatment. The conventional insertion can be challenging when using high-viscosity glass-ionomer cement. This study evaluated the formation of gaps and voids after three insertion methods using micro-CT. Teeth underwent removal of occlusal and proximal caries through the atraumatic restorative treatment technique. Then, they were fixed in an artificial dental arch to simulate the clinical condition and were restored using three insertion methods: conventional, Centrix injection, and double-filling. Previous dentin conditioning procedures, steel matrix and wooden wedge application, and post-insertion procedures (digital compression and surface protection) were the same. The material was inserted using a manual instrument in the conventional technique and was inserted with a syringe in the Centrix injection group. In the double-filling technique, the tooth received a first layer of a flowable ionomer (through modifying the powder/liquid ratio), and a second layer (with standard ratio) was applied before the final set of the first one. A micro-CT unit scanned each tooth before and after restoration. Each cavity was defined as the volume of interest, and the volumes of gaps and voids were calculated. Data were analyzed using one-way ANOVA and Tukey posthoc test (p < .05). Double-filling had improved filling volume with lower values for gap volume, followed by Centrix injection. The conventional technique had the highest gap volume. No statistically significant difference was observed for void volume. Double-filling demonstrated fewer gaps, followed by Centrix injection, which is critical to obtain better adhesive, remineralizing, and antibacterial activities.

Insertion methods and gap/void formation in atraumatic restorative technique: A micro-CT analysis

Abstract Wetting the dentin is critical to atraumatic restorative treatment. The conventional insertion can be challenging when using high-viscosity glass-ionomer cement. This study evaluated the formation of gaps and voids after three insertion methods using micro-CT. Teeth underwent removal of occlusal and proximal caries through the atraumatic restorative treatment technique. Then, they were fixed in an artificial dental arch to simulate the clinical condition and were restored using three insertion methods: conventional, Centrix injection, and double-filling. Previous dentin conditioning procedures, steel matrix and wooden wedge application, and post-insertion procedures (digital compression and surface protection) were the same. The material was inserted using a manual instrument in the conventional technique and was inserted with a syringe in the Centrix injection group. In the double-filling technique, the tooth received a first layer of a flowable ionomer (through modifying the powder/liquid ratio), and a second layer (with standard ratio) was applied before the final set of the first one. A micro-CT unit scanned each tooth before and after restoration. Each cavity was defined as the volume of interest, and the volumes of gaps and voids were calculated. Data were analyzed using one-way ANOVA and Tukey posthoc test (p < .05). Double-filling had improved filling volume with lower values for gap volume, followed by Centrix injection. The conventional technique had the highest gap volume. No statistically significant difference was observed for void volume. Double-filling demonstrated fewer gaps, followed by Centrix injection, which is critical to obtain better adhesive, remineralizing, and antibacterial activities.

Resumo O molhamento da dentina parcialmente desmineralizada no fundo da cavidade dentária é fundamental para o sucesso do tratamento restaurador atraumático. No entanto, o método de inserção convencional pode ser desafiador ao usar cimento de ionômero de vidro de alta viscosidade. Este estudo avaliou a formação de gaps e vazios internos após três métodos de inserção de cimento de ionômero de vidro de alta viscosidade usando micro-CT. Dez terceiros molares foram submetidos à remoção de cárie oclusal através da técnica de tratamento restaurador atraumático e complementação proximal (com ou sem lesão pré-existente). Em seguida, foram fixados em uma arcada dentária artificial para simular a condição clínica. Os dentes foram restaurados usando a técnica de tratamento restaurador atraumático com três métodos de inserção: convencional, injeção Centrix e dupla inserção. Os procedimentos anteriores de condicionamento dentinário, inserção de matriz de aço, aplicação de cunha de madeira e procedimentos pós-inserção do material (como compressão digital e proteção de superfície) foram os mesmos para os três grupos testados. O material foi inserido com instrumento manual na técnica convencional, seguindo a metodologia clássica do tratamento restaurador atraumático. O material foi inserido com um dispositivo desenvolvido especificamente para esse fim na técnica de inserção com seringa tipo Centrix. Na técnica de dupla obturação, o dente recebeu uma primeira camada do cimento de ionômero de vidro mais fluido (obtido através da modificação da relação pó/líquido), e uma segunda camada (com relação pó/líquido padrão) foi aplicada antes da presa final da primeira. Um micro-CT escaneou cada dente antes e depois da restauração. Cada cavidade foi definida como o volume de interesse, e os volumes de gaps e vazios foram calculados. Os dados foram analisados por ANOVA one-way e teste post-hoc de Tukey com nível de significância de 5%. A dupla inserção melhorou significativamente o volume de preenchimento com valores percentuais mais baixos para o volume do gap, seguido pela injeção com seringa tipo Centrix. A técnica convencional apresentou o maior percentual de volume de gap. Nenhuma diferença estatisticamente significativa foi observada para o volume de vazios internos. O grupo de dupla inserção demonstrou menor formação de gaps, seguido pelo grupo de injeção com seringa tipo Centrix, que é fundamental para obter melhores atividades adesivas, remineralizantes e antibacterianas.

Effect of prior silane application on the bond strength of a universal adhesive to a lithium disilicate ceramic.

STATEMENT OF PROBLEM: Universal adhesives combine silane and various monomers in a single bottle to make them more versatile. Their adhesive performance is unclear. PURPOSE: The purpose of this in vitro study was to assess the effects of an additional silane application before using a universal adhesive on the adhesion between a disilicate glass ceramic and a composite resin by using a microshear bond strength test (µSBS) and fracture analysis immediately and after thermocycling. MATERIAL AND METHODS: One hundred lithium disilicate glass ceramic disks were divided into 10 groups for bond strength testing according to the following 3 surface treatments: silane application (built-in universal adhesive or with additional application), adhesive (Adper Single Bond Plus [SB, 3M ESPE], Scotchbond Universal Adhesive [U, 3M ESPE], and mixed U with Dual Cure Activator [DCA, 3M ESPE]); or thermocycling (half of the specimens were thermocycled 10000 times). After surface treatment, 5 resin cylinders were bonded to each disk and submitted to a µSBS test. The failure mode was analyzed under a stereomicroscope and evaluated by scanning electron microscope and energy-dispersive x-ray spectroscopy. Data from the µSBS test were analyzed by 3-way ANOVA followed by the Tukey HSD post hoc test (α=.05). RESULTS: An additional silane application resulted in a higher µSBS result for all adhesive groups (P<.05). CONCLUSIONS: Ceramic surface treatment influenced the performance of adhesives, which may be improved with an additional silane application.

Avaliação da eficácia das fitas para clareamento dental / Evaluation of the Effectiveness of Dental Whitening Strips

O objetivo deste estudo foi discutir, através de uma revista da literatura, a eficácia, limitações e efeitos colaterais relacionados com as fitas para clareamento dental. Dentre os vários artigos apresentados neste estudo, todos relatam um efeito branqueador em esmalte e dentina com o uso de fitas clareadoras impregnadas com peróxido de hidrogênio entre 5% a 10%. Porém, pouco se sabe se o grau de clareamento atingido se equipara ao das demais técnicas clareadoras. Além disso, somente um estudo acompanhou a duração do resultado por três meses. Portanto, mais pesquisas são necessárias para avaliar o tempo total de duração do clareamento através do uso de fitas, assim como comprovar se o grau de clareamento alcançado pode ser comparável às outras técnicas.

The aim of this study was to discuss, through a literature review, the effectiveness, limitations and side effects related to tooth whitening strips. Among the various articles shown in this study, all of them describe a whitening effect on enamel and dentin using whitening strips impregnated with hydrogen peroxide between 5% and 10%. However, little is known whether the degree of whitening achieved is comparable to the effect produced by other bleaching techniques. Furthermore, only one study followed the length of the result for three months. Therefore, more research is needed to assess the full duration of whitening through the use of whitening strips, as well as demonstrate the degree of whitening that can be achieved compared to other techniques.

Comparação de matizes em diferentes marcas comerciais de resina composta / Comparison of matrices in differents commercial brands of composite resins

Introdução: a seleção de cor é um processo complexo, influenciado por muitas variáveis. Esse estudo analisou comparativamente a cor de quatro resinas compostas A2 de diferentes marcar comerciais entre si e entre as resinas, e pela escala Vita Classical avaliou0se se essa diferença é captável pelo olho humano. Métodos: foram confeccionados seis corpos de prova para cada resina composta de cor A2 utilizda: Amelogen (grupo 1), Fitek Supreme (grupo 2) , Estelite (grupo 3) e Point 4 (grupo 4). Foi realizada, subsequentemente, análise por fotografia e pelo sistema CIE Lab de cada corpo de prova e da palheta da escala de cor Vita Classical. Os dados obtidos foram submetidos à análise estatística pelos métodos One Way ANOVA e de Tukey HSD. Resultados: houve diferença estatisticamente significativa entre os grupos 2 e 4 (p menor que 0,05). A resina Point 4 obteve os resultados mais próximos aos da palheta A2 da escala Vita Classical, embora seja uma variação clinicamente inaceitável. A resina Fitek Supreme apresentou os resultados mais discrepantes em relação à escala. As resinas Amelogen e Estelite não apresentaram resultados satisfatórios, mas se aproximaram mais da resina Point 4. Conclusões: ao serem analisadas resinas compostas de uma mesma cor, facilmente são encontradas discrepâncias, tanto entre diferentes amostras da mesma resina como em marcas comerciais distintas, além das divergências presentes entre a resina e a palheta de mesma cor da escala. Sendo assim, aumenta-se a dificuldades para confecção de uma restauração estética pelo profissional

Introduction: The color selection is a complex process affected by many variables. This study comparatively analyzed the color of four A2 composite resins from different commercial brands among them and between resins and the Vita Classical shade tab, assessing whether this difference is perceptible by the human eye. Methods: Six specimens were prepared for each A2 composite used: Amelogen (group 1), Filtek Supreme (group 2), Estelite (group 3) and Point 4 (group 4). By means of photographic and CIE Lab system, each specimen and of the Vita Classical's scale shade palette were analysed. The data were statistically analyzed by the One Way ANOVA and Tukey HSD methods. Results: There was a statistically signifcant difference between groups 2 and 4 (p < 0.05). Point 4 resin obtained results closer to the A2 palette from the Vita Classical scale, although in a clinically unacceptable range. Filtek Supreme resin presented the most discrepant results compared to the same scale. Amelogen and Estelite resins didn't showed satisfactory results, but it were closer to Point 4. Conclusions: Analyzing composites of the same color it can be easily found discrepancies between different samples from the same shade as well in different commercial brands, besides the differences present among the resin and the scale's palette from the same color. Therefore, it increases the diffculty of making an esthetic restoration by the professional.

Restoration of noncarious cervical lesions: when, why, and how.

At this time, restoration of noncarious cervical lesions (NCCLs) is a common occurrence in clinics nowadays. Some reasons for this are the growth of the elderly population, a smaller rate of tooth loss, and possibly the increase of some etiologic factors. These factors include inadequate brushing techniques in gingival recession cases, corrosive food and drink consumption, and occlusal stress concentrating factors (occlusal interferences, premature contacts, habits of bruxism, and clenching). Unfortunately, Class V restorations also represent one of the less durable types of restorations and have a high index of loss of retention, marginal excess, and secondary caries. Some causes for these problems include difficulties in isolation, insertion, contouring, and finishing and polishing procedures. This work aims to help dentists in choosing the best treatment strategy, which necessarily involves steps of problem identification, diagnosis, etiological factor removal or treatment, and, if necessary, restoration. Finally, appropriate restorative techniques are suggested for each situation.

Opções de preparo para laminados cerâmicos: quais, quando, como e por quê? / Choices to ceramic veneer preparations: which, when, how and why?

Os novos conceitos da Odontologia preconizam um tratamento mais conservador, que devolva estética e função. Entre as possibilidades restauradoras disponíveis, os laminados cerâmicos estão alcançando um alto nível de excelência por se encaixarem nesses novos padrões da Odontologia Moderna. Restabelecendo estética e função, as facetas indiretas de porcelana são consideradas um tratamento restaurador conservador, quando comparadas a outros tipos de restaurações, como as coroas totais...

The new concepts of Dentistry advocate a more conservative treatment that restores asthetic and functional aspects. Among the possibilities available, restorative ceramic laminates are reaching a high level of excellence that fits these new patterns of Modern Dentistry. Restoring aesthetic and function, indirect porcelain venners are considered a conservative restorative treatment when compared to other types of restorations such as full crows...

Effect of a glaze/composite sealant on the 3-D surface roughness of esthetic restorative materials.

The main goal of the current study was to evaluate the surface roughness of tooth-colored restorative materials after different finishing/polishing protocols, including a liquid polisher (BisCover, BISCO, Schaumburg, IL, USA). The restorative materials tested included two nanofilled resin composites (Filtek Supreme, 3M Dental Products, St Paul, MN, USA and Grandio, Voco, Cuxhaven, Germany), one resin-modified glass ionomer cement (Vitremer, 3M Dental Products) and one conventional glass ionomer cement (Meron Molar ART, Voco). The finishing/polishing methods were divided into five groups: G1 (compression with Mylar matrix), G2 (finishing with diamond burs), G3 (Sof-Lex, 3M Dental Products), G4 (BisCover, BISCO, after diamond burs) and G5 (BisCover after Sof-Lex). Five cylindrical specimens of each material were prepared for each group according to the manufacturer's instructions. The finishing/polishing methods were performed by a single operator in one direction to avoid variations at low speed (15,000 RPM). The surface roughness was evaluated using a 3-D scanning instrument with two parameters considered (Ra and Rz). The data was analyzed using one-way ANOVA followed by a multiple comparison Tukey's test. The results showed that BisCover (BISCO) was capable of reducing surface roughness and provided polished surfaces for all materials, enhancing smoothness over already polished surfaces (Sof-Lex, 3M Dental Products) and achieving polishing after finishing with diamond burs.

Influência de um polidor resinoso na adesão de Streptococcus mutans in situ / Resinous polisher influence over in situ adhesion of Streptococcus mutans

A placa bacteriana é um biofime específico formado sobre tecidos orais, materiais restauradores, aparatos ortodônticos ou qualquer outra superfície na cavidade bucal. Entre diversos fatores a rugosidade das superfícies é de relevância crítica na qual os procedimentos de acabamento e polimento apresentam um papel vital na dentística restauradora. O objetivo deste trabalho foi de avaliar os níveis de rugosidade de quatro materiais restauradores dentais diferentes submetidos a três tipos de tratamento superficial (compressão por matriz mylar - grupo controle negativo, acabamento com pontas diamantadas de granulação fina - grupo controle positivo e aplicação de polidor resinoso BisCover™ (Bisco) depois do acabamento com as pontas diamantadas) e a influência sobre a colonização por Streptococcus mutans no biofilme inicial. Os materiais analisados foram: um cimento de ionômero de vidro convencional (Ionofil® / Voco), um cimento de ionômero de vidro modificado por resina (Vitremer™ / 3M ESPE), um compósito nano-particulado (Filtek Supreme™ / 3M ESPE) e um compósito nano-híbrido (Grandio® / Voco). A rugosidade foi medida por um instrumento de escaneamento 3-D (TalyScan 150 / Taylor Hobson) e a avaliação quantitativa de S. mutans no biofilme inicial foi realizada in vivo através da extração do biofilme dental (formado sobre discos fixados sobre moldeiras individuais usadas por um voluntário por um período de 24 horas). Um total de oito discos de cada material em cada grupo de tratamento superficial foi feito para o ensaio microbiológico e da mesma forma cinco discos foram feitos para cada situação para a mensuração da rugosidade. Resultados: análise superficial 3-D: o tratamento superficial e o tipo de material afetaram significativamente os valores de Ra e Rz (P<0.05)...

Dental plaque is a specific biofilm formed over oral tissues, restorative materials, orthodontic apparatus or any other surface in oral cavity. Among several factors, the roughness of surfaces is one of critical relevance in which finishing and polishing procedures play a vital role in restorative dentistry. The aim of this work was to evaluate the roughness levels of four different restorative dental materials submitted to three kinds of superficial treatment (compression with mylar matrix - negative control group, finishing with fine grain diamond points - positive control group and application of a resin polisher BisCover™ (Bisco) after finishing with the diamond points) and the influence on Streptococcus mutans colonization in initial biofilm. The materials analyzed were: one conventional glass ionomer cement (Ionofil® / Voco), one resin modified glass ionomer cement (Vitremer™ / 3M ESPE), one nano-filled composite resin (Filtek Supreme™ / 3M ESPE) and one nano-hybrid composite resin (Grandio® / Voco). The roughness was measured with a 3-D scanning instrument (TalyScan 150 / Taylor Hobson ) and the quantitative evaluation of S. mutans in initial biofilm was performed in vivo through dental biofilm extraction (developed over discs fixed on custom-fitted trays wore by one volunteer for a 24 hours period). A total of eight discs of each material in each superficial treatment group were made for the microbiological assay and in the same way five discs were made for each situation for the roughness measurement. Results: 3-D surface analyses: the surface treatment and the type of material significantly affected the Ra and the Rz values (P<0.05)...

Avaliaçäo clínia de um novo dessensibilizante dentinário / Clinical evaluation of a novel dentinal desensitizer

O objetivo deste trabalho foi avaliar o efeito de um novo dessensibilizante dentinário (D/Sense2-Centrix). Um grupo de 40 pacientes afetados pela hipersensibilidade dentinária de diferentes etiologias foi tratado seguindo as recomendaçöes do fabricante. O exame de sensibilidade após aplicaçäo foi realizado imediatamente, depois de 7 e 30 dias. Foram encontrados resultados positivos em todos os períodos de exames, exceto quando a percepçäo de dor inicial era muito alta e em dois dos grupos estudados (nichos preparados para próteses e sobre dentes com sensibilidade, após restauraçöes com resina)