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

OBJECTIVES: 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). MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. CLINICAL SIGNIFICANCE: 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.