A SHORT-TERM AND LONG-TERM SHEAR BOND STRENGTH STUDY USING ACIDS OF VARYING DILUTIONS ON BOVINE DENTIN

Objectives: The purpose of this study was to evaluate the short-(24 h) and long-(180 day) term shear bond strengths of resin to bovine denti ne etched with varying dilutions of aqueous solutions of phosphoric an d maleic acids. Methods: Bovine dentine surfaces were prepared using w ater irrigated #600 grit SIC paper. The dentine surfaces were etched i n groups of 10 teeth using various dilutions of phosphoric or maleic a cid. Using the Scotchbond Multipurpose System (SBMP; 3M Co., MN, USA) and a wet technique the etched surfaces were primed and unfilled bondi ng resin (UBR) was applied to the dentine surface within the confines of a gelatin cylinder. A cylinder of filled resin (Z 100; 3M Co., MN, USA) was then photocured and the specimens were then stored in water f or 24 h or 180 days prior to shear bond testing to failure. Results: T he results showed that high bond strengths were recorded using acids w hich were more dilute than those commercially available. There were al so indications that phosphoric acid is not the etching acid of choice for the SBMP system. Conclusions. The results of this study showed tha t high bond strengths can be achieved in dentine using etching acids w hich are more dilute than those commercially available. Maleic acid ap pears to be the etchant of choice for the SBMP system. (C) 1997 Elsevi er Science Ltd.