Improved photochemical bonding of composites to dentin using 4-methacryloxyethyl trimellitate anhydride

The main objective was to evaluate the use of 4‐methacryloxyethyl trimellitate anhydride (4‐META) to improve bonding of composite materials to dentin. Bowen's resin, containing camphoroquinone, was polymerized by exposure to visible light. In composites, made with a silanated silicate, inclusion of 4‐META (3%) had little effect in increasing mechanical strength or adhesion to bovine teeth. However, direct application of 4‐META via acetone solution was found to be an effective way of increasing tensile adhesive strength; by 240% to dentin (to 7.2 MPa) and by 160% to enamel (to 10.8 MPa). Applying the experience mentioned above, 4‐META was used to bond a proprietary photocuring microfilled composite material to Class V cavities in freshly extracted human teeth. After thermal cycling between water baths held at 5°C and 60°C, all dentin restorations without 4‐META failed, as judged by marginal leakage of a dyestuff. In contrast, using 4‐META there was no leakage in 9 out of 10 cases. In restorations involving enamel, 4‐META failed to prevent marginal leakage at the enamel margins but did prevent penetration along the dentin/composite interface. It is concluded that 4‐META shows great promise for preventing marginal leakage at dentin/composite interfaces.