Comparative study of influence on tensile bond strength of a composite to dentin using Er : YAG laser, air abrasion, or air turbine for preparation of cavities

Objectives: The purpose of this study was to evaluate, in vitro, the tensil e bond strength of the Single Bond (3M) adhesive system placed over dentin surfaces treated with air turbine, Er:YAG laser without contact and in focu sed or air abrasion. Summary Background Data: The use of dentin adhesives i s a well-established clinical routine among the dentists. However, there ha ve been few reports comparing the influence of the Er:YAG laser, air abrasi on, and air turbine on the Single Bond tensile bond strength of adhesives s ystems to dentin fact that could influence which tools dentists select for use in cavity preparations. Methods: Twenty-three extracted retained human molars were used in this study. The coronal portion was divided in two part s and fixed in acrylic resin; the occlusal surface was abraded to a 2-mm wi dth with a mechanic lathe until the dentin surface was completely exposed. The dental portions were divided into three groups of 15 each and treated w ith Er:YAG laser, air abrasion, or air turbine. A 3 mm hole in the center o f each tooth was marked off using contact paper. Single Bond (3M) adhesive system was applied after acid phosphoric at 35% application for 15 see over dentin surfaces. A resin composite cone was built into the delimited area to accomplish the tensile bond strength test on the EMIC universal test mac hine. The specimens were then evaluated by stereoscopy to determine the typ e of failures into the dentin-adhesive-resin composite surface. Results: Th e tensile test was performed using the universal testing machine EMIC DL-20 00 at a cross-head speed of 0.5 mm/min. The average results were: air turbi ne (17.52 MPa), Er:YAG laser (16.65 MPa) and air abrasion (15.83 MPa). Stat istical treatment by ANOVA and Tukey's test (p < 0.01) showed no significan t differences between the groups tested. The tensile bond strength test to the dentin showed no significant difference among the three groups when the Single Bond was used after the 35% phosphoric-acid conditioning. The stere oscopy showed a predominant adhesive failure in all groups. Conclusion: The se results suggest that Single Bond tensile bond strength is the same as de ntin prepared by Er:YAG laser, air abrasion, or air turbine.