Effect of silica fillers on bonding performance of 5th generation dental adhesive

Thesis supervisor: Dr. Baolin Deng.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Dental adhesives are widely used in various direct and indirect dental restorations for bonding application. Resin adhesives have evolved through the last three decades to achieve excellent performance both in research and in clinical. Hypersensitivity is one of the most important aspects to evaluate a dental adhesive in clinical, and higher bonding strength is closely related to lower hypersensitivity. Therefore, from the research aspect, higher bonding strength of dental adhesives is always a goal to achieve. Based on the bonding procedure, dental adhesives are classified into two categories including total-etch and self-etch adhesives. This study mainly focused on a total-etch adhesive model with an objective to study the effect of different silica fillers on the bonding performance. Four kinds of commercial silica fillers with different size and surface treatment were incorporated into the same resin matrix in various percentage. The properties of the adhesives obtained with such fillers were studied in terms of viscosity, water contact angle, degree of conversion and micro-tensile bonding strength. The longevity of the adhesive bonding strength was also studied through aging test. From this study, adhesive with Filler 2 produced the highest initial micro-tensile bonding strength, while adhesives with Filler 3 and Filler 4 produced better bonding longevity. Based on the data obtained from this study, suggestions for filler selection to improve adhesive properties were provided.Includes bibliographical references (pages 44-53)