IADR Abstract Archives
Influence of Chlorohexidine Pretreatment on Durability of Resin-Dentin Bonds
This study investigated the influence of 2% chlorhexidine (CHX) digluconate pretreatment on dentin bond durability of a self-etch adhesive system after in vitro aging.
Methods:
Flat occlusal dentin surfaces were prepared in 42 extracted human molars. The teeth were randomly divided into 3 distinct experimental groups of 14 teeth each according to the aging stressors applied to the restoration (immediate (IM), thermocycle (TC), thermo-mechanical loading (TML)). Half of the teeth in each group were restored after the application of 2% CHX. For all groups, composite resin blocks were built up over bonding agent (Prelude, Danville Materials, CA) application. For aging, the teeth were either exposed to a thermocycling regiment of 10000 cycles between 5o C and 55o C, or placed in a chewing simulator (TML; 100,000×50 N) following thermocycling for simulation of oral conditions. The restored teeth were vertically sectioned to obtain 1.0 +/- 0.1 mm2 cross-sectional composite-dentin beams. Microtensile bond strengthswere measured at a crosshead speed of 0.5 mm/minute. Data were analyzed with a two-way ANOVA and Tukey’s HSD (p< 0.05).
Results:
Mean Microtensile Bond Strengths [MPa] ± SD |
||
Groups |
No CHX |
CHX |
IM |
25.0 ± 2.4a |
17.9 ± 2.9b |
TC |
27.0 ± 4.2a |
16.0 ± 2.2b |
TML |
15.3 ± 4.9b |
24.5 ± 3.1a |
*Means with same letter are not significantly different
Bond strengths were decreased in the IM and TC samples with CHX application (p < 0.05). However, in the TML group, CHX application provided the bond strengths that were similar to the ones in the IM and TC groups without CHX application.
Conclusion:
CHX pretreatment decreases dentin bond strengths when tested either immediately or after thermocycling. Simulation of intraoral conditions through TML has different effects: CHX treatment increases bond strength to the same level found in the immediate and thermocycled groups without CHX.