Study On The Influence Of The Different Dentin On Their Bond Strengths With Resin

The main method which judges whether an adhesive system works or not is the bonding strength test.Undoubtedly, the vital teeth in human mouth are the best subjects for bonding test. Because collecting the experimental samples is not so easy that most of scholars do their works with extracorporeal teeth. However, it is nearly impossible to simulate oral circumstance completely to test the properties of adhesive materials. On the other hand , once extracted, the teeth would change their properties definitely. So, whether the bond strength tested under in vitro condition indicates the real in vivo amount is always concerned by researchers. In order to compare the adhesive performance between the dentin hi vivo and in vitro, to find a valid way to evaluate the quality and efficacy of adhesive systems, in this disquisition, we studied and compared the microtensile bond strengths and the microstructure under SEM of four recently introduced commercial dentin adhesive systems (SingleBond, Bond-1, Prime&Bond NT and One-Step) applied in both in vitro and in vivo conditions.The results are showed below:1. This study tested the bond strengths of the new adhesive systems under the environments in vivo and in vitro, the data was then analyzed, which showed no significant difference, so the test results of the dentin adhesives experiments in vitro with extracorporeal teeth could indicate then- bond strengths in vivo reliably and actually.2. The results tested on the dentin in vivo and in vitro all showed that the bond strengths of One-Step, Prime&Bond NT and Bond-1 whose solvents are aceton were not significantly different, and were all higher than Single Bond whose solvents are alcohol and water.3. The results showed that the microtensile bond strengths of the new dentin adhesive systems were all high, the highest tested amount is 30.18 ?.77Mpa, which provide their good clinical performance.