Pulpal and micro-organism responses to two experimental dental bonding systems

Several new bonding systems have been reported that promote strong adhesion. This in vivo study involves treatment with two experimental bonding systems of Class V cavity preparations in the teeth of three Macaca fascicularis primates and reports the pulpal responses and degree of micro-organism invasion associated with each treatment. In each monkey, the teeth in the upper left quadrant were treated with the experimental solution, containing 2.5% aluminum nitrate + 1.5% oxalic acid + 4.9% NPG, followed by application of PMDM and Silux XL composite. The lower right quadrant was treated with the experimental solution, containing 5.7% NPG + 2.4% nitric acid, followed by PMDM and Silux XL composite. The upper right and lower left quadrants were treated with clinical materials to establish positive and negative controls. After four, 25, and 59 days, the teeth were removed and underwent routine histological and bacteriological evaluation. Slight pathological conditions were noted for superficial and deep responses, but all values approached 0.0 by the 59th day. Micro-organisms were seen under only 12% of the restorations. Both experimental systems appear to be safe for human clinical trials.