Effect of a Hydroxyapatite Forming Desensitizer on Dentin Bond Strength

To measure the dentin shear bond strength (SBS) of four adhesives before and after an application of a hydroxyapatite (Tetracalcium phosphate and dicalcium phosphate anhydrate, Teethmate Desensitizer, Kuraray) forming desensitizer.

Method: Freshly extracted intact human molars (n=80) were wet-ground with a series of abrasive discs (80-320-grit) to obtain flat dentin surfaces. Teeth were randomly divided into 8 groups of 10 specimens each. Half were treated with TEETHMATE Desensitizer (Kuraray Noritake Dental, Tokyo, Japan) according to the manufacturer’s instructions.  No desensitizer was applied to the remaining teeth (control). Clearfil Universal Bond was used in the self-etch technique and all other adhesives were used in the total-etch technique. Adhesives were applied to the bonding area according to manufacturer’s instructions and light cured. A Teflon tube (diameter=1.5mm) filled with Clearfil AP-X composite resin (Kuraray Noritake Dental, Japan) was placed over the adhesive and light cured (S10 LED curing light 3M ESPE, St Paul, MN/820Mw/cm² /20s) from 4 directions.  Specimens were stored (incubator/24hours/ 37ºC/distilled water).  Specimens were placed into a stainless steel fixture mounted on a universal testing machine (Instron- 5565, MA), and loaded to failure (1mm/min), and statistically analyzed (ANOVA and Tukey T post-hoc test (p=.05).

Result: (n=10/group) (Mean ±SD)

Conclusion: The application of Teethmate desensitizer to dentin did not affect bond strengths of 4 adhesives (p>.05). Supported in part by a grant from Kuraray.