ObjectivesThis study evaluated the effects of light exposure through simulated indirect ceramic restorations (SICR) on hardness (KHN) of dual-cured resin cements (RCs), immediately after light-activation and 24 h later.Material and Methods Three dual-cured RCs were evaluated: eco-Link (Ivoclar Vivadent), Rely X ARC (3M eSPe), and Panavia F (Kuraray Medical Inc.). The RCs were manipulated in accordance to the manufacturers’ instructions and were placed into cylindrical acrylic matrixes (1-mm-thick and 4-mm diameter). The RC light-activation (Optilux 501; Demetron Kerr) was performed through a glass slide for 120 s (control group), or through 2-mm or 4-mm thick SICRs (IPS empress II; Ivoclar Vivadent). The specimens were submitted to KHN analysis immediately and 24 h after light-activation. The data obtained at the 2 evaluation intervals were submitted to 2-way ANOVA repeated measures and post-hoc Tukey’s test (pre-set alpha of 5%).ResultsLower KHN was observed when light-activation was performed through SICRs for eco-Link at all evaluation intervals and for Rely X ARC 24 h later. For Panavia F, no significant difference in KHN was observed between control and experimental groups, regardless of evaluation interval. Most groups exhibited higher KHN after 24 h than immediately after light-activation, with the exception of Rely X ARC light-activated through SICR, as no significant difference in KHN was found between evaluation intervals.ConclusionLight overexposure did not compensate for light intensity attenuation due to the presence of SICR when Rely X and eco-Link were used. Although hardness of such RCs increased over a 24-h interval, the RCs subjected to light overexposure did not reach the hardness values exhibited after direct light exposure.

There was less development of caries lesion around LA-prepared cavities than around the DB-prepared cavities; however, no synergistic cariostatic effect was observed between the Er:YAG laser and glass ionomer cement.

Objective: The aim of this study was to evaluate the influence of cavity preparation and restorative materials containing fluorides in the prevention of secondary caries lesion development in situ. Methods: A total of 120 blocks obtained from human teeth were divided into two groups and standardized cavities were prepared using diamond burs (DB) or Er,Cr:YSGG-laser [20 Hz, 4.0W, 55% water, 65% air (LA)]. They were divided into three subgroups according to the restorative material (n = 20): glass-ionomer cement (GI), resin modified glassionomer (RM) or composite resin (CR). Blocks were fixed in palatal intra-oral appliances worn in situ by 20 human volunteers, who dropped 20% sucrose solution eight times daily. After 21 days, blocks were removed and restorations were cross-sectioned to evaluate microhardness [Knoop hardness number (KHN)] underneath enamel surface from 30 to 200 lm. Factors ''cavity preparation,'' ''restorative materials,'' and ''depth'' were evaluated by three way ANOVA, followed by Tukey test ( p < 0.05). Results: The results showed lower microhardness in cavities prepared with DB than in cavities prepared with LA. At 30 lm, there were no statistical significant differences with regard to ''cavity preparation'' or ''restorative materials'' factors. In depth evaluation, the enamel microhardness progressively increased as a function of depth for the GI groups. In the groups prepared with LA at 60 lm/90 lm, there were no significant differences between GI and RM materials, whose microhardnesses were significantly higher than that of CR. Conclusions: Cavity preparation using Er,Cr:YSGG laser increases caries resistance of enamel walls, and reduce caries lesion depth development regardless of fluoride presence in the restorative material. CR showed higher caries lesion development than GI, and RM showed intermediate results.

OBJETIVO: O presente estudo tem como objetivo apresentar de forma prática e objetiva, por meio de um caso clínico, a otimização da colagem indireta, utilizando guia de colagem indireta criada por meio do fluxo de trabalho digital. MÉTODOS: Após análise criteriosa do caso, optou-se pela técnica de colagem indireta dos braquetes. O escaneamento foi exportado para o software OrthoAnalyzer 2017 (3Shape, Copenhagem, DK), que permite o posicionamento correto dos braquetes e tubos nas faces vestibulares dos dentes e a criação de uma guia indireta, a qual foi gerada em impressora da marca Anycubic, modelo Mono X. A resina utilizada para impressão foi a OrthoFlex, da marca Yller. RESULTADOS: Os resultados obtidos por meio da colagem indireta virtual se mostraram bastante eficientes, em especial em relação ao tempo de cadeira e à qualidade do alinhamento e nivelamento, quando comparada aos métodos convencionais. CONCLUSÃO: O fluxo de trabalho digital associado à técnica da colagem indireta trouxe uma maior precisão no posicionamento dos braquetes, favorecendo um tratamento mais curto e com melhor finalização, e podendo-se imprimir a guia na própria clínica, com uma impressora 3D.