Dentistry

Abstract

The Effect of Surface Treatment and Adhesive System on the Durability of Composite Repairs

Lukas Comba,Pavel Bradna*,Erika Lenčová,Jana Dušková,Děvana Houšová

Controversy exists concerning the optimal procedure for composite restoration repairs. The aim of the study was to investigate the effect of surface treatment, adhesive system and long-term storage in water and a surfactant solution on the bond strength between aged and repair composite materials. Surfaces of a light-cured micro-hybrid composite (Filtek Z250) aged in distilled water for five months at 37°C were treated by grinding with SiC paper P320 or by air abrasion (Rondoflex, Al2O3, 50 μm). The build-ups were made with the same composite material using Optibond FL (OPF), Gluma Comfort Bond (GLU) and Clearfil SE Bond (CLF) adhesive systems. The build-ups were sectioned into sticks, stored at 37^°C for four months in distilled water or in a solution of a surfactant sodium lauryl sulfate (SLS, 1.5 wt. %) to accelerate water penetration in the adhesive joint. Control specimens were stored in distilled water for 24 h at 37^°C. The results were analyzed with a three-way ANOVA followed by Fisher’s LSD post-hoc tests at α=0.05 and with Weibull statistics. The surface morphology of treated and fractured surfaces was analyzed using light and scanning electron microscopy. The bond strengths of the majority of groups treated by air abrasion were significantly higher and more stable after long-term storage in water and SLS solution than those treated by grinding. These results indicated that air abrasion combined with clinically well-proven adhesives may provide increased strength and long-term stability of composite repairs.