Influence of Surface Treatment of Lithium Disilicate on Roughness and Bond Strength.

PURPOSE: To evaluate the effect of different concentrations of hydrofluoric acid (HF) on the surface roughness of a ceramic reinforced by lithium disilicate and on the bond strength formed between the ceramic and self-adhesive resin cement. MATERIALS AND METHODS: A total of 100 disks of IPS e.max Press ceramic (Ivoclar Vivadent) reinforced by lithium disilicate were prepared as follows: group 1 remained untreated (control group); in groups 5-20, 5-40, and 5-60, the surfaces were etched with 5% HF for 20, 40, and 60 seconds, respectively; in groups 10-20, 10-40, and 10-60, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively; and in groups 10-20P, 10-40P, and 10-60P, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively, followed by treatment with 37% phosphoric acid for 5 seconds. Surface roughness and bond strength were analyzed with confocal microscopy and microshear testing, respectively. The values obtained were statistically analyzed using paired t test and two-way ANOVA followed by Tukey post hoc test at a 5% significance level. RESULTS: Surface roughness was influenced by the concentration and exposure time of acid applied (P < .05) and by the combination of these two factors (P < .05). Treatment with 10% HF for 40 seconds (group 10-40) achieved the highest roughness value. In contrast, bond strength was affected only by the acid exposure time (P < .05). CONCLUSION: Conditioning of lithium disilicate ceramics can change the surface morphology, thereby affecting bond strength with resin cement.

Odontologia estética adesiva ­ a reconstrução do sorriso com laminados cerâmicos / Adhesive aesthetic Dentistry ­ smile reconstruction with ceramic laminates

O uso crescente de laminados cerâmicos na Odontologia Restauradora vem tornando-se cada vez mais popular entre os cirurgiões dentistas devido à sua excelência estética. No entanto, observa-se muita inquietação no meio clínico devido à falta de conhecimento científico, experiência clínica, imprevisibilidade dos resultados e longevidade, além de muitas dúvidas quanto ao emprego das possíveis técnicas. Devido a isto, o objetivo deste trabalho é relatar um caso clínico sobre laminados cerâmicos, bem como o protocolo de trabalho para sua confecção. Concluiu-se que as facetas laminadas apresentam longevidade clínica e grande aceitação por parte do paciente. Mas não é necessário apenas o conhecimento das técnicas aplicadas e material mais indicado, pois é de suma importância que o profissional esteja seguro, tenha conhecimento, e além de tudo, saiba aplicar de forma adequada o passo a passo, pois erros cometidos em qualquer etapa do tratamento poderão interferir no sucesso e longevidade (AU).

The increasing use of ceramic laminates in Restorative Dentistry has become increasingly popular among dental surgeons, because of their aesthetic excellence. However, there is much concern in the clinical environment due to lack of scientific knowledge, clinical experience, unpredictability of results and longevity, and many doubts about the use of possible techniques. Due to this, the objective of this work is to report a clinical case on ceramic laminates, as well as the protocol of work for its preparation. It was concluded that the laminated facets present clinical longevity and great acceptance by the patient. But it is not only necessary to know the applied techniques and the most appropriate material, because it is of the utmost importance that the professional is secure, has knowledge and, moreover, knows how to apply the step- -by-step in an adequate manner, since errors committed at any treatment stage may interfere with success and longevity (AU).