Restaurações diretas com materiais bioativos: observações clínicas, in vitro e revisão sistemática / Direct restorations with bioactive materials: clinical observations, in vitro and systematic review

O objetivo do ensaio clínico foi avaliar o desempenho clínico de 2 materiais bioativos (Cention N e EQUIA Forte) em comparação a resina composta. O estudo in vitro teve como objetivo avaliar o desenvolvimento de lesões de cárie induzida por desafio cariogênico bacteriano na margem de restaurações em esmalte e dentina com Cention N com e sem adesivo, EQUIA Forte e resina composta. A revisão sistemática teve como objetivo responder a seguinte pergunta: A avaliação clínica de restaurações em dentes permanentes com materiais bioativos evidencia maior sucesso do que restaurações com materiais não bioativos? Para o estudo clínico foram selecionados 120 participantes aleatoriamente divididos em 3 grupos (n=40), TC: Tetric N-Ceram, EF: EQUIA Forte, CN: Cention N. O preenchimento das cavidades foi realizado seguindo as indicações do fabricante. Foi utilizado o dispositivo de fluorescência DIAGNOdentTM Pen para avaliação da recorrência de cárie. No estudo in vitro foram confeccionados 100 espécimes a partir de dentes bovinos. Foram divididos em 5 grupos (n=20) metade em esmalte e metade em dentina: Cention N sem adesivo (CN), Cention N com adesivo (CA), EQUIA Forte (EF); Tetric N-Ceram (TC); e sem restauração (SR). Foram submetidos a envelhecimento térmico; leitura de microdureza Knoop (KHN) inicial, esterilizados e expostos a um desafio cariogênico com Streptococcus mutans por 28 dias. Lesões de cárie artificial foi quantificado por meio de KHN superficial e de subsuperfície, e análise com microscopia de luz polarizada. Os dados foram submetidos a ANOVA 1 fator e teste Tukey no esmalte e teste de Kruskal-Wallis na dentina. Em esmalte os grupos EF, CN, CA apresentaram menor porcentagem de perda da microdureza (%PMS) 57,85%, 63,88% e 66,65% respectivamente. Na dentina, EF, CN e CA apresentaram menores valores de %PMD sendo 31,7%, 34,1% e 40,8% respectivamente. Os valores mais altos de %PMS foram registrados para os grupos TC e SR tanto na dentina como no esmalte. Na revisão sistemática, com base na pergunta de pesquisa e estratégia PICO: P- Dentes permanentes, I- Restaurações (classe I, classe II, classe III, classe V) com materiais bioativos, C- Restauração com materiais não bioativos, O- Retenção; foi traçada a estratégia de busca. Após a obtenção dos estudos eles foram analisados por dois revisores independentes. No total foram 27 ensaios clínicos randomizados, com acompanhamento mínimo de 2 anos, foram os qualificados para realizar a revisão e meta-análise em rede. Os resultados de meta-análise em rede mostraram que em cavidades classe III cimento de ionômero de vidro modificado (CIV modificado), foi significativamente mais propenso a falhas do que a resina composta (RC), em restaurações classe I e II, o compômero foi significativamente mais propenso a falhas do que a RC e em restaurações classe V o cimento de ionômero convencional (CIV convencional) foi significativamente mais propenso a falhas do que o CIV modificado. No estudo in vitro foi evidente o maior potencial de inibição da desmineralização dos materiais bioativos. Na revisão sistemática ficou evidente que a maioria de materiais bioativos apresentam um bom comportamento, em relação as taxas de retenção e desempenho clínico. (AU)

The objective of the clinical trial was to evaluate the clinical performance of 2 bioactive materials (Cention N and EQUIA Forte) compared to composite resin. The in vitro study aimed to evaluate the development of caries lesions induced by bacterial cariogenic challenge at the margin of enamel and dentin restorations with Cention N with and without adhesive, EQUIA Forte and composite resin. The systematic review aimed to answer the following question: Does the clinical evaluation of restorations in permanent teeth with bioactive materials show greater success than restorations with nonbioactive materials? For the clinical study, 120 participants were randomly selected and divided into 3 groups (n=40), TC: Tetric N-Ceram, EF: EQUIA Forte, CN: Cention N. The filling of the cavities was performed following the manufacturer's instructions. The DIAGNOdentTM Pen fluorescence device was used to assess caries recurrence. In the in vitro study, 100 specimens were made from bovine teeth. They were divided into 5 groups (n=20) half in enamel and half in dentin: Cention N without adhesive (CN), Cention N with adhesive (CA), EQUIA Forte (EF); Tetric N-Ceram (TC); and without restoration (SR). They were subjected to thermal aging; initial Knoop microhardness (KHN) reading, sterilized and exposed to a cariogenic challenge with Streptococcus mutans for 28 days. Artificial caries lesions were quantified using surface and subsurface KHN and analysis with polarized light microscopy. Data were submitted to 1-way ANOVA and Tukey test on enamel and Kruskal-Wallis test on dentin. In enamel, groups EF, CN, CA had the lowest percentage of microhardness loss (%PMS) 57.85%, 63.88% and 66.65% respectively. In dentin, EF, CN and CA presented lower %PMD values, being 31.7%, 34.1% and 40.8% respectively. The highest %PMS values were recorded for the TC and SR groups in both dentin and enamel. In the systematic review, based on the research question and PICO strategy: P- Permanent teeth, I- Restorations (class I, class II, class III, class V) with bioactive materials, C- Restoration with non-bioactive materials, O- Retention; the search strategy was designed. After obtaining the studies, they were analyzed by two independent reviewers. In total, 27 randomized clinical trials, with a minimum followup of 2 years, were qualified to perform the review and network meta-analysis. The results of network meta-analysis showed that in class III cavities modified glass ionomer cement (modified GIC) was significantly more prone to failure than composite resin (RC), in class I and II restorations, the compomer was significantly more prone to failure than RC and in class V restorations the conventional ionomer cement (conventional GIC) was significantly more prone to failure than the modified GIC. In the in vitro study, the greatest potential for inhibiting the demineralization of bioactive materials was evident. In the systematic review it was evident that most bioactive materials have a good behavior in relation to retention rates and clinical performance (AU).

Monowave and polywave light-curing of bulk-fill resin composites: degree of conversion and marginal adaptation following thermomechanical aging.

Aim: This study aimed to evaluate the effect of polymerization with either a monowave (MW) or a polywave (PW) light-curing unit (LCU) on the degree of conversion (DC) and marginal adaptation following thermomechanical aging of an ormocer bulk-fill resin composite (RC) (Admira fusion X-tra Bulk Fill - AB), a methacrylate-based bulk-fill RC (Tetric N-Ceram Bulk Fill - TB) and a conventional RC (Tetric N-Ceram - TC). Methods: DC was assessed in five samples of each RC using Fourier transform infrared spectroscopy. For determination of marginal adaptation, standard preparations were made in 60 bovine incisors, divided into three groups, according to the RC. The bulk-fill RC was inserted in a single increment of 4 mm. In contrast, the conventional RC was inserted in three increments. Marginal gap was evaluated after thermomechanical aging. Data were analyzed using a two-way analysis of variance (ANOVA) and Tukey's tests for multiple comparisons (α = 0.05). Results: The two-way ANOVA showed a significant effect (p<.05) of the RC factor but not of the LCU factor. The Tukey test showed that TB had the significantly lowest DC followed by TC, and with AB having the significantly highest DC. For the marginal adaptation, a significant effect was found for the LCU factor and the for the interaction RC × LCU (p<.05). Groups light-cured with PW showed significantly wider marginal gaps than MW. TC presented wider marginal gaps (17.36 µm) when cured with PW than when cured with MW (13.05 µm). The two bulk-fill RC resulted in similar marginal gap formation to each other. Conclusion: The ormocer-based bulk-fill RC showed a higher DC than the methacrylate-based bulk-fill RC but similar marginal adaptation. The LCU, MW or PW, had no significant influence on the DC, and no relevance on the marginal adaptation.

The influence of a liner on deep bulk-fill restorations: Randomized clinical trial.

OBJECTIVE: The aim of this study was to evaluate the influence of a liner on the clinical performance of deep posterior restorations performed with bulk-fill composite. METHODS: 30 subjects received two restorations on deep preparations in posterior teeth, without pulpal exposure, after selective carious-tissue removal in one-stage. The internal walls reached the inner quarter of dentin, but with a radiographically detectable zone of firm dentin remaining. The pulpal protection using a layer of glass ionomer composite liner (Ionoseal, Voco) was applied in just one preparation. The adhesive system Futurabond U (Voco) was applied in all preparations, which were restored with the bulk-fill pure Ormocer nanohybrid composite (Admira Fusion Xtra - Voco), in up to 4 mm thick increments. All restorations were evaluated using the FDI criteria after 7 days, 6, 12 and 24 months postoperatively. RESULTS: After 24-months, 25 patients attended the recall and 50 restorations were evaluated. The Fisher's statistical analysis (5%) showed no difference between the techniques for the esthetic, functional and biological properties. No postoperative sensitivity was reported for both groups. CONCLUSION: The application of a liner did not influence the clinical performance of deep restorations with bulk-fill Ormocer composite. CLINICAL RELEVANCE: The application of a liner with a GIC-based material did not have a significant effect on the clinical performance of bulk-fill restorations and seems to be unnecessary for the material tested.

Effects of artificial staining on bulk-filled resin composites.

PURPOSE: To evaluate the color stability of bulk-fill resin composites (RC) in comparison to conventional RC submitted to artificial staining. METHODS: 15 specimens of each RC were prepared. Five bulk-fill RC [X-tra Base (XB), Filtek Bulk-Fill Flowable (FBF), Admira Fusion X-tra (AD), Tetric N-Ceram Bulk-Fill (TB), and Filtek Bulk-Fill (FB) ], and two conventional RC [GrandioSO (GO) and Filtek Z350XT (FXT) ] were used. After preparation of the samples, the specimens were immersed in a staining broth for 5 weeks and repolished. The color change was assessed using a spectrophotometer. Data were analyzed using one-way ANOVA, Tukey's tests, and paired t-test. RESULTS: The bulk-fill flowable (XB and FBF) presented color change clinically acceptable (ΔE< 2.7) after staining. Among the bulk-fill regular resins, only AD presented clinically acceptable values (ΔE= 1.99). Regarding the conventional resins, GO presented a significantly lower color change than the other resins, but was not significantly different from AD. For all the resins, except AD, the repolishing procedures resulted in a significant decrease of color change. Tested resins did not present the same behavior under staining, despite their similarities. All the resins stained above the perceptibility threshold (ΔE> 1.2). After repolishing, the color change was reduced overall. CLINICAL SIGNIFICANCE: Color stability of resin composites was related to the properties of the resin material. The staining degree was related to the replacement of the restorations and repolishing contributes to the maintenance and longevity of these composites.

Influência do modo de foto ativação no grau de conversão, e adaptação marginal e interna de restaurações classe II com resinas compostas bulk fill / Influence of light curing mode on degree of conversion, and marginal and internal adaptation of class II bulk fill resin restoration

O objetivo deste estudo foi avaliar a efetividade de diferentes modos de foto ativação das resinas compostas bulk fill comparando com as resinas convencionais, analisando sua influência na irradiância, no grau de conversão, assim como na formação de fendas internas e marginais em restaurações classe II tipo slot vertical, após envelhecimento artificial. Cento e sessenta incisivos bovinos foram cortados e desgastados para simular dentes posteriores, nos quais foram realizados preparos classe II. Os espécimes foram divididos em quatro grupos de acordo com o material restaurador utilizado: Tetric N-Ceram Bulk Fill (TB), Admira Fusion X-tra Bulk fill (AB), Tetric N-Ceram (TC) e GrandioSO (GO). As resinas bulk fill foram inseridas em incremento único de 4 mm e nos demais grupos foi utilizada a técnica incremental oblíqua (2 mm). A foto ativação foi realizada com os aparelhos do tipo Monowave (MW) ou Polywave (PW) nos dois modos (alta intensidade continua e rampa). A medição da irradiância foi feita utilizando espectroradiômetro Patient Simulator (MARC-PS). O grau de conversão foi avaliado através da reflectância total atenuada (ATR) do espectrômetro (FTIR). As superfícies superiores das amostras foram irradiadas in loco durante 20 s. O espectro da superfície inferior foi registrado em tempo real e após 15 min da irradiação. As fendas foram avaliadas em estereomicroscópio (50x). As fendas marginais externas foram avaliadas antes e após a ciclagem termomecânica. Para fenda interna, os espécimes foram seccionados e então avaliados. Os dados foram submetidos à ANOVA umo e dois fatores e teste Tukey. Em relação á irradiância o aparelho LED Monowave apresentou maior valor de irradiância (1822,2 mW/cm2 - AIC; 1748,1 mW/cm2 - R); na análise do GC, o teste ANOVA dois fatores mostrou diferença significativa (p<0,05) para o fator tipo de resina. A resina TB apresentou o menor grau de conversão, e AB o maior GC. Para fenda marginal foi encontrada diferença significativa para o fator fotopolimerização e interação resina x fotopolimerização (p<0,05). Resina TC fotopolimerizada PW/AIC apresentou maior média de fenda marginal (13,94 µm) e TC fotopolimerizada MW/AIC a menor (9,59 µm). Após o envelhecimento termomecânico a resina GO fotopolimerizada PW/R apresentou maior porcentagem de aumento de fenda marginal (48,54%) e maior fenda interna quando fotopolimerizada MW/AIC (85,05 µm). Concluiu-se que o tipo fotopolimerização não influenciou no grau de conversão. As restaurações polimerizadas com o fotopolimerizador Polywave apresentaram os maiores valores de fenda marginal externa. As resinas bulk fill apresentaram menores valores de fenda marginal e interna após o envelhecimento termomecânico quando comparadas com restaurações de resinas convencionais(AU)

The objective of this study was to evaluate the influence of different photo activation modes on irradiance, the degree of conversion and formation of internal and external gaps in class II restorations using bulk fill resins. One hundred and sixty bovine incisors were cut and worn to simulate posterior teeth, in which class II preparations were performed. The specimens were divided into four groups according to the restorative material used: Tetric N-Ceram Bulk Fill (TB), Admira fusion X-tra Bulk fill (AB), Tetric N-Ceram (TC), GrandioSO (GO). The bulk fill resins were inserted in a single increment of 4 mm, and in the other groups, the incremental oblique technique was used. The photo activation was performed with a Monowave (MW) or Polywave (PW) light curing devices selecting two modes (high continuous intensity (HCI) and soft start (SS)). The irradiance measurement was performed using Patient Simulator (MARC-PS) in HCI and SS modes, for 20 s. For the degree of conversion, 2 mm and 4 mm high and 5 mm diameter molds were prepared for resin insertion directly on the attenuated total reflectance (ATR) spectrometer (FTIR). The upper surfaces of the samples were irradiated in situ for 20 s with the light curing apparatus in the modes (HCI) and (SS), the lower surface spectra was recorded continuously in real time and then at 15 min after irradiation. For the evaluation of the external gap each specimen was evaluated twice, one before and one after the thermomechanical cycling. For internal gap, the specimens were sectioned and evaluated using the stereomicroscope using a 50x magnification. About the irradiance, the Monowave LED showed the highest irradiance values (1822,2 mW/cm2 - HCI; 1748,1 mW/cm2 - SS), in the DC analysis, the two way ANOVA test showed significant difference (p <0.05) for the resin type. TB showed the lowest DC, with a statistical difference for AB. For the marginal gap, a significant difference was found for the photopolymerization factor and resin x photopolymerization interaction (p <0.05). TC light cured by PW/HCI showed the highest average marginal gap (13.94 µm) and TC light cured by MW / HCI revealed the lowest (9.59 µm) marginal gap. After thermomechanical aging, GO light cured by PW / SS had a higher percentage of increasing marginal gap (48.54%) and the highest internal gap when light cured by MW / HCI (85.05 µm). It was concluded that the type of photopolymerization did not influence the degree of DC. The restorations light cured by PW device showed the highest external marginal gaps. Bulk fill resins exhibited lower marginal and internal gap values after thermomechanical aging when compared with conventional resin(AU)