Tensile bond strength of ceramic brackets bonded to porcelain facets.

The number of adults requesting orthodontic treatment is constantly growing, with a resultant increase in the need to bond brackets to porcelain restorations. Because adults often favor more esthetic ceramic brackets, it is important to evaluate the bond strength of ceramic to porcelain restorations and the integrity of the porcelain surface after debonding. Eighty porcelain facets, resembling mandibular incisors, were used. The surfaces were conditioned by either hydrofluoric acid or microetching. Mandibular incisor ceramic brackets were bonded with 1 of 2 adhesives: Ideal 1 without silane or Right-On with silane. Debonding was performed with a tensile force on a universal testing machine. The mode of bond failure was determined macroscopically, and the integrity of the porcelain facets was evaluated microscopically. The results showed that the type of porcelain conditioning technique affects the tensile bond strength of both adhesives. Conditioning with hydrofluoric acid resulted in significantly higher bond strength (Ideal 1, 7.7 +/- 3.0; Right-On, 7.1 +/- 2.6) than conditioning by microetching (Ideal 1, 4.1 +/- 2.3; Right-On, 3.8 +/- 2.4; P <.05). The mode of bond failure was mainly adhesive, and the porcelain facets were not damaged during debonding. This study shows that both Ideal 1 and Right-On are suitable for bonding ceramic brackets to porcelain restorations, if the porcelain has been conditioned with hydrofluoric acid.