Effect of surface treatments on the adhesion of fiber post to resin composite core material.

Abstract

This study aimed to evaluate the effect of various surface treatments of a fiber post on the bond strength to a composite core. The polished flat surfaces of fiber posts received different treatments: C (no surface treatment), S (silanization only), HS (30% hydrogen peroxide etching followed by silanization), HNS (etching with a 30% hydrogen peroxide/5 wt% sodium bicarbonate mixture followed by silanization), and SBS (sandblasting and then silanization). Resin composite cylinders were bonded on each pretreated surface and all bonded samples were stored in water at 37ºC for 24 h, with half of them additionally thermocycled for 10,000 cycles before microshear testing. Surface morphology and elemental composition of the conditioned post surfaces were studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. The HNS exhibited the highest bond strength, regardless of thermocycling (p<0.05). Although etching and sandblasting increased surface roughness, sandblasting caused structural damage of the post.