Effect of saliva contamination on bond strength of brackets bonded with moisture-insensitive primer and conventional primer
Zainab M.O. Musafer, Eman M. El Shorbagy, Safaa A. GhobashyAims
The aim of this study was to analyse the impact of saliva contamination on shear bond strength of brackets bonded with moisture-insensitive primer (MIP) versus conventional primer.
Patients and methods
Intact 84 human maxillary first premolar were moulded in color-coded acrylic blocks. The buccal surfaces of all specimens were polished and then enamel bonding area were etched for 30 s with 37% phosphoric acid, rinsed with a water spray for 10 s, and thoroughly air-dried for 2–3 s. The specimens were randomly divided into four groups (n = 21) according to contamination and priming agents: group I: Dry condition (no saliva contamination), group II: wet contamination after application of conventional primer, group III: wet contamination after application of MIP primer, group IV: wet contamination before application of MIP primer. Transbond XT Light Cure Adhesive Paste (3 M unitek, Monrovia, CA, USA); was used as adhesive in all tested groups. SBS was measured using a universal testing machine, and adhesive remnant index (ARI) scores were assessed under a stereomicroscope at 10 × magnification.
Results
The mean shear bond strength values for all studied groups were 19.67 ± 3.29, 8.81 ± 2.87, 18.68 ± 3.39, and 15.49 ± 2.84, respectively. There was a highly significant difference between group I and II (
Conclusions
Saliva contamination significantly affects shear bond strength of orthodontic brackets when conventional orthodontic primers are used. MIP could be effectively used to overcome the effect of saliva contamination on the bond strength of orthodontic brackets. Timing of saliva contamination either before or after primer application has significant effect on shear bond strength when using MIP.