TiF4 improves microtensile bond strength to dentin when using an adhesive system regardless of primer/bond application timing and method.

Abstract

This study evaluated the bond strength of a two-step conventional adhesive system to dentin pretreated with 2.5 % titanium tetrafluoride (TiF(4)) according to application timing (before or after acid conditioning) and primer/adhesive application method (active or passive). Dentin surfaces were randomly treated with different adhesive procedures (n = 6): etching with phosphoric acid (PA) + primer/adhesive (Adper Single Bond 2/3M ESPE) actively applied; PA + primer/adhesive passively applied; TiF(4) before PA + primer/adhesive actively applied; TiF(4) before PA + primer/adhesive passively applied; TiF(4) after PA + primer/adhesive actively applied; and TiF(4) after PA + primer/adhesive passively applied. A composite block was built onto the tooth, which was sectioned into sticks (adhesive area of approximately 1 mm(2)). Microtensile bond strength tests and the failure mode were determined. Two-way ANOVA revealed no significant interaction between TiF(4) application timing and primer/adhesive application method (p = 0.184). The use of TiF(4), before or after PA significantly increased bond strength values (p < 0.001). There was no significant difference in bond strength values when using TiF4 before or after PA. The primer/adhesive application method had no influence on bond strength, regardless of whether TiF(4) was used (p = 0.906). Failure mode was predominantly adhesive. The use of TiF(4) promoted higher immediate bond strength to dentin. The conventional adhesive system may be applied either actively or passively, regardless of TiF(4) application timing. Pretreatment with TiF(4) increased bond strength in a conventional two-step adhesive system to dentin, regardless of the primer/adhesive application method and the timing of dentin pretreatment.