Resina composta restauradora pré-aquecida como agente de cimentação adesiva de restaurações indiretas

Abstract

The use of restorative preheated resin composite for adhesive luting of indirect restorations as an alternative to traditional resin-based cements is increasingly popular. However, there is still room for improving the clinical technique, understanding how to select the composite properly and reduce film thickness, as well as on reporting long-term clinical results. This thesis addressed the topic by means of three studies. The first study was an in vitro investigation of the effects of preheating at 69°C on viscosity, film thickness, and temperature loss of 10 contemporary resin composites, in addition to the effect of ultrasound energy on the resulting film thickness. This study showed that materials with distinct formulations react differently to preheating, affecting viscosity and film thickness. Optimal working time of the preheated composites was short, suggesting that clinicians should adequate the luting sequence to take advantage of higher temperatures found in the first 15s after preheating. In addition, it was observed that application of ultrasound energy was effective in reducing film thickness and may aid restorative resin composites to achieve films below 50µm. The second study was a clinical technique reporting the luting of ceramic laminate veneers with preheated composite, describing a step-by-step procedure that may be used by clinicians in their working routine, including the application of ultrasound energy over the ceramic to optimize film thickness. The third study was a case report of a clinical treatment in which ceramic laminate veneers were adhesively luted to maxillary anterior teeth of a patient using preheated resin composite and showed excellent clinical service and remarkable marginal integrity after 123 months of follow up. A smooth marginal transition between ceramic, luting agent, and tooth (area of adhesive continuity) and the absence of marginal gaps and ditching indicated that the restorative resin composite was able to withstand the abrasive and surface challenges imposed by the oral environment in the long term. In general, this thesis shows that preheated resin composite for luting indirect restorations may be considered an excellent clinical option and that the overall performance of the clinical technique depends on proper selection of a resin composite that responds properly to preheating. There is still room for further controlled clinical studies on the topic.