Artificial Saliva Contamination Effects on Bond Strength of Self-etching Primers.

Objective: To test the hypothesis that there is no difference in the bond strength with or without contamination with artificial saliva when using two different self-etching primers (Transbond Plus and iBond) in comparison with a conventional acid-etching method (37% phosphoric acid and Transbond XT) for bonding of orthodontic brackets. Materials and Methods: One hundred fifty extracted human premolars were randomly allocated to six different groups, with 25 teeth in each group. Orthodontic metal brackets (APC II, Victory Twin 22 UNIV) were used. For contamination, a saliva replacement (Ptyalin) was applied. After contamination the surface was air-dried for 5 seconds and the bonding procedure continued. The bonded teeth were stored in deionized water at 37°C for 30 days and then thermocycled for 24 hours before debonding with a universal testing machine. The load was recorded at bond failure. The location of adhesive failure was determined under magnification using the adhesive remnant index (ARI). Results: Clinically acceptable bond strengths were found for all primers used in this study. The contamination by saliva significantly decreased the bond strength when using the conventional acid-etching method (t = 0.0001). Self-etching primers were less influenced by saliva contamination. There was no significant difference in the ARI score among the groups (P > .05). Conclusions: Saliva contamination significantly decreased the bond strength when the conventional acid-etching method was used. The self-etching primers were influenced the least. The bond strengths achieved for the self-etching primers and the conventional etching method after saliva contamination were not significantly different. [ABSTRACT FROM AUTHOR]