Sealant bond strengths of CO2 laser‐etched versus acid‐etched bovine enamel

Abstract

Background and Objective The purpose of this study was to evaluate sealant shear bond strength on bovine enamel with standard acid etching compared with CO2 laser etching. Study Design/Materials and Methods Bovine enamel was prepared either by acid or laser etching and divided into four experimental groups, either acid or laser-etched teeth with or without a primer. A gelatin capsule was used to place the sealant on the prepared enamel surface and the bond tested in shear. Also surface roughness was evaluated by using a surface analyzer and an atomic force microscope. Results Shear bond strength results were the following: acid etch = 8.8 ± 3.8 MPa, acid etch with primer = 10.3 ± 5.5 MPa, laser etch = 4.0 ± 1.1 MPa, and laser etch with primer = 6.2 ± 2.3 MPa. Analysis of variance statistical analysis found no significant difference in bond strength between the acid-etched groups. However, the laser-etched groups had significantly lower bond strengths from the acid-etched teeth. In addition, a significant difference was observed between the laser-etched groups, where the use of the primer helped to increase the bond strength of the sealants. The surface roughness was significantly greater on the laser-etched teeth at the μm level (by using a surface analyzer) from the acid-etched and the control specimens. No difference in roughness (by using an atomic force microscope) was observed at the nanometer level between the laser and acid-etched teeth. Conclusion For these particular settings, the laser-etched teeth resulted in lower bond strengths to enamel and the use of a primer increased the bond strength for laser-etched teeth only. Lasers Surg. Med. 27:111–118, 2000. © 2000 Wiley-Liss, Inc.