[Studies on bonding of light-cured bonding agent to dentin]

A light-cured bonding agent consisted of 50 wt% BisGMA and 50 wt% 2 HEMA was prepared in order to investigate the effect of light curing system on the bonding to etched dentin treated with 37 wt% phosphoric acid (PA), 10 wt% citric acid (CA), 10 wt% maleic acid (MA), 10 wt% citric acid-3 wt% ferric chloride (10-3) and 0.5 M EDTA.2 Na (EDTA) solutions. The bond strength to dentin treated with 10-3 solution was statistically higher than to dentin treated with the other etchant. The acid-proof dentin layers with about 1-2 microns thickness at the interface between resin and dentin treated with CA, MA, and 10-3 solutions were visible with SEM. The presence of Ca, P, and Br elements in the layers was confirmed by EPMA analysis. The bond strength was greatly dependent upon the physical property of the layer because difference in Knoop hardness of the etched dentin surfaces and the dentin surface after bond testing was greatest when used 10-3 solution.