Effect preparation on the hybrid layer with resin cement

Abstract

Purpose: The aim of this study was to evaluate the effect of preparation mode of dentin on the thickness and quality of hybrid layer with resin cement and an adhesive system. Methods and materials: Sixty sound human teeth extracted within six months were obtained from the Uberaba University human tooth bank under ethical approval # 27584814.2.0000.5145. The teeth were cut 2mm below the ADJ mesio-distally to expose the coronal dentin and divided into three groups (n=15). (1) The dentin surface was prepared with a fine particle diamond bur; (2) with a course particle diamond bur and (3) with multi laminated carbide bur. Composite resin blocks (Tetric Ceram, Ivoclar-Vivadent) were fabricated and cemented on the dentin surfaces with Single Bond Universal adhesive system mixed with OPC bioactivator and RelyX ARC resin cement (all from 3MESPE) and stored for 24h in distilled water at 37 ◦C. Following, the restored teeth were sectioned perpendicular to the bonding surface using a low speed saw machine to obtain sections of 1mm thickness. The section pieceswere cleaned and individually embedded in epoxy resin (Buehler) and after the resin polymerization the pieces were prepared to scanning electron microscope analysis to verify the hybrid laser. Results: The fine particle diamond bur (6.55 m) produced a thinner hybrid layer compared to the coarse diamond bur (9.18 m). The multi laminated carbide bur (7.88 m) did not differ from the diamond burs. The quality of the hybrid layer was equal to all preparation modes. Conclusion:The type of rotary instrument did influence the thickness of the hybrid layer for the resin cement studied, but did not affect the quality of it.