Longevity of Bond Strength of an Indirect Composite Resin to Dentin Using Conventional or Self-Adhesive Resin Cementation: Influence of Dentin Pretreatment with TiF₄.

The purpose was to evaluate the influence of dentin pretreatment with titanium tetrafluoride (TiF₄) on the longevity of bond strength (BS) of an indirect composite to dentin, using conventional resin cementation strategy or a self-adhesive resin cement. Forty third human molars with exposed dentin surfaces were used. The teeth were divided into groups (n = 10), according to the cementation strategy and the presence or absence of pretreatment with TiF₄. Microtensile strength testing and failure mode analysis were performed after 24 hours, 180 and 360 days of storage in water. Split-plot ANOVA and Tukey's test showed that BS was significantly higher when the conventional strategy was used, regardless of the time period, and of the application or no application of pretreatment with TiF₄ (p ⟨0.0001). When TiF₄ was used for both cementing strategies, BS was lower after 360 days (p = 0.0019). Both cementing strategies led to the formation of a shallow hybrid layer, regardless of the presence of TiF₄. BS was higher when the conventional cementation strategy was used, regardless of TiF₄ pretreatment. TiF₄ used as a pretreatment agent associated with different types of resin cementation was unable to maintain adhesive bond strength in the long term.