Influence of dentin pretreatment with 2.5% titanium tetrafluoride on inhibiting caries at the tooth-restoration interface in situ

Abstract

Objective: Investigate the effects of dentin pretreatment with 2.5% titanium tetrafluoride (TiF₄) aqueous solution followed by two-step self-etching (CLE/Clearfil SE Bond) and one-step self-etching adhesive systems (SBU/Single Bond Universal) on carious lesion inhibition at the tooth-restoration interface using an in situ model.

Design: Sixty-four cavities at the enamel-dentin junction of dental fragments were randomly distributed according to groups (n=16): 1) TiF₄+CLE; 2) TiF₄+SBU; 3) CLE; 4) SBU. Cavities were restored using resin composite, and placed in intraoral palatal devices used by 16 volunteers for 21days, to induce caries formation in situ. The fragments were then ground-flat to perform Knoop microhardness tests. Nine indentations were performed on each enamel and dentin substrate, subjacent to the restoration. Analysis of variance and Tukey's test were applied.

Results: Enamel: groups receiving TiF₄ dentin pretreatment (regardless of adhesive system and tooth-restoration interface distance) presented higher hardness means at a depth of 25μm from the outer tooth surface (p<0.0001). Dentin: groups receiving CLE presented higher means when applying TiF₄ pretreatment, whereas groups restored with SBU presented higher means without pretreatment (p=0.0003).

Conclusions: Dentin pretreatment with TiF₄ inhibited demineralization of the enamel interface in situ, regardless of the adhesive, and TiF₄ pretreatment followed by CLE application showed higher potential for inhibiting dentin demineralization at the interface.

Keywords: Adhesive system; In situ; Microhardness; Titanium tetrafluoride.