A study evaluated the influence of saliva contamination on the shear bond strength of orthodontic brackets bonded with self-etching primers. The article by Maiaa, et al involved 135 bovine incisors that were randomly divided into 3 groups, and exposed enamel surfaces were bonded with Transbond Plus Self Etching Primer (TB) (3M Unitek), Adhese Single Bottle (AD) (Ivoclar Vivadent), and Self Etch Bond (SE) (Vigodent). Each group was subdivided into 3 treatments (n = 15): saliva contamination (S), saliva contamination and deionized water rinsing (SW), and no salivary contamination (C). Resin composite (Z-100 [3M ESPE]) was applied to all samples to bond the orthodontic brackets. Shear bond strength testing was carried out in a universal testing machine operating at 1.0 mm per minute. The results were statistically analyzed with 2-way analysis of variance (ANOVA) and Tukey tests (P < .05). The study found that saliva contamination caused a significant decrease of enamel strength in the groups bonded with TB and SE compared with the SW and C groups. Enamel bond strengths of the C and SW groups were higher than those of the TB group, followed by the AD and SE groups. Enamel bond strength after S was higher than AD, followed by TB and SE. The study concludes that the shear bond strengths of orthodontic brackets to enamel and the performance of the adhesive systems were influenced by contamination with saliva.
(Source: American Journal of Orthodontics and Dentofacial Orthopedics. July 2010, Volume 138, Issue 1, Pages 79 to 83)
