Tensile Bond Strength of a One-Bottle Adhesive System to Indirect Composites Treated with Er:YAG Laser, Air Abrasion, or Fluoridric Acid

Objective: This in vitro study evaluated the tensile bond strength of Single Bond adhesive system to indirect composite surfaces treated with Er: YAG laser, fluoridric acid, or air abrasion. Background Data: Application of adhesive techniques is well established in restorative dentistry, yet the influence of surface treatments on the bond strength of adhesive systems to indirect composite restorations prior to luting or repair procedures remains unclear. Methods: Two hundred and ten samples made of three indirect composites (BelleGlass, Sculpture, and Targis) were divided into 21 groups (n = 10) and treated with (1) control (no treatment); (2) silane (RelyX 3M ceramic primer); (3) 10% fluoridric acid; (4) Er: YAG laser; (5) Er: YAG laser + 10% fluoridric acid; (6) air abrasion; and (7) air abrasion + 10% fluoridric acid. Afterwards, silane and Single Bond adhesive system were applied on each treated surface, and a direct composite resin (Z250) cone was built. The prepared specimens were submitted to tensile bond strength test and stereoscopy evaluation to determine the type of failure after rupture. Results: Bond strength mean values were statistically different in function of indirect composite and surface treatment. BelleGlass treated with Er: YAG laser had the highest mean value (22.92 MPa), and Sculpture conditioned with fluoridric acid had the lowest mean (11.88 MPa). Stereoscopy showed a predominant cohesive failure in Targis resin and mixed type for Sculpture and BelleGlass. Conclusions: These results suggest that Single Bond tensile bond strength improves with Er: YAG laser as a surface treatment compared to fluoridric acid or air abrasion.