First Approach of a Protocol for Test Bone Adhesives

INTRODUCTION Despite its origins in the mid-1950s with a bone adhesive called Ostamer [1], the development of bone adhesives is still in its early stages and is not a mature field. There lacks a consensus on aspects of adhesive performance and bond strength measurement. As a result, there are not standard tests for quantifying and evaluating the adhesive strength at the interface between the bone tissue and biomaterial [2-4]. The purpose of this study is to design and standardize a protocol capable of measuring the bond strength of bone adhesives. The protocol consists of mechanically evaluated different formulations of adhesives based on chitosan and alginate, selected based on their individual potential as bone adhesives [5]. Three mechanical tests were implemented. The first and second methods are tensile tests with a controlled fracture at 90o (TT90) or 45° (TT45) relative to the load direction along a constant transverse section of 10 mmx10 mm. The third test is a three point flexural test (3PFT), where the deflection of cancellous bone sheets is tested with and without adhesive reinforcement. In order to propose a methodology to apply the adhesive in bone specimens, a dental adhesive Adper Single Bond (3M Espe) was used. Finally, the results from the mechanical characterization were analyzed using ANOVA (p<0.05) and pos hoc Tukey tests to compare the bond strength of each formulation against Kryptonite® (Doctor ́s Research Group, Inc.,), a commercial bone cement with adhesive properties that has shown promising in vivo results and has FDA approval [6].