BOND STRENGTH OF GLUMA CPS USING THE MOIST DENTIN BONDING TECHNIQUE

Purpose: To investigate the effects of acetone or water based Gluma pr imers on bonding efficacy when applied to acid-etched wet, dry or rewe tted dentin. Materials and Methods: Shear bond strength (SBS, 24 hours ) was measured on human dentin etched with 20% phosphoric acid gel and rinsed with water in the wet (blot dried), the conventional (2 second s air blast), the dry (10 seconds air drying), and the rewetted stage (10 seconds air drying, remoistening and blot drying). The priming sol ution was either the original water based or an acetone based experime ntal Gluma primer. Cavity sealing performance and depth of resin impre gnation were determined by solvent and by technique along the margins of 4.5 mm wide cylindrical dentin cavities with 90 degrees cavosurface angle. Results: The SBSs of the wet technique groups were approximate ly 18 MPa, irrespective of the primer solvent. Conventional drying gav e an SBS almost as high (16.5 MPa). Rewetting was highly effective wit h acetone as the primer solvent. The dry techniques resulted in modera te (water) and poor (acetone) bond strengths. The cavity margins of ac etone based primer treated specimens were consistently gap free with t he wet technique. The other seven groups showed between two and six ga ps in each group of six specimens. The resin impregnated layer (RIL) t hicknesses were 12.5 mu m approximately in the wet groups, and thus id entical with the total depth of demineralization resulting from the 30 -second etching. The alternative techniques showed significantly thinn er RILs particularly in the dry groups (7.5 mu m).