BOND STRENGTH VERSUS DENTIN STRUCTURE - A MODELING APPROACH

Bond strengths of a hypothetical hydrophilic dentine-bonding agent wer e calculated as a function of dentine depth and resin strength to eval uate the importance of several variables in a simple model. The tested hypothesis was that the total bond strength was the sum of the streng ths of resin tags, hybrid layer and surface adhesion. Each of these th ree variables has a range of values that can influence its relative co ntribution. The resulting calculations indicate the potential for high er bond strengths to deep dentine than to superficial dentine in non-v ital dentine and the importance of resin strength in the development o f strong bonds. Comparison of the calculated bonds with published valu es indicated that they were within the same order of magnitude. Such t heoretical modelling of dentine bonding can identify the relative impo rtance of variables involved in the substrate, resins and surface adhe sion.