• Kochanipa Saisopa D.D.S.
• Sirivimol Srisawasdi D.D.S., Cert. (Operative Dentistry), M.S., Ph.D.

Objective To evaluate and compare the effects of two desensitizing toothpastes and a regular fluoride
toothpaste on microtensile bond strength of two adhesive agents to dentin.

Materials and methods The labial surfaces of forty bovine incisor crowns were ground flat, exposing
dentin. The teeth were then randomly divided into four groups corresponding to the toothpaste used:
1) Sensodyne^® Rapid Relief (GlaxoSmithKline, UK), 2) Colgate Sensitive Pro-Relief^TM (Colgate-
Palmolive, Thailand), 3) Colgate^® Regular Flavor (Colgate-Palmolive, Thailand), and 4) immersed in
artificial saliva (control). Each tooth in groups 1-3 was brushed with its respective dentifrice under
constant loading (200 g) at 250 strokes/min for 2 minutes, twice daily for three days. Each group was
then randomly divided for composite build-up using the following adhesive agents: 1) Optibond^® XTR
(Kerr, USA), or 2) Optibond^® FL (Kerr, USA). After curing the adhesives, a light-cured resin
composite (Premise^TM, Kerr, USA) was used for a core build-up. The samples were sectioned into four
specimens with 1 ± 0.1 mm thick and wide. The microtensile bond strength test was performed using
a universal testing machine at a cross-head speed of 0.5 mm/min. The data were analyzed using
two-way ANOVA and Tukeyûs multiple comparison tests with significance set at p < 0.05. Fracture
analysis of the debonded dentin surface was performed using a stereomicroscope.

Results Bond strength was statistically significantly reduced by the application of desensitizing
toothpastes (p < 0.0001), and the type of adhesive agents had a significant effect on bond strength
(p < 0.0001).

Conclusion The uses of desensitizing toothpaste reduce bond strength of adhesives to dentin.

(CU Dent J. 2014;37:225-40)