THE EFFECT OF DENTIN BONDING AGENTS ON THE MICROLEAKAGE OF PORCELAIN VENEERS

Objectives. This in vitro study was conducted to investigate the effec t of dentin bonding agents on the microleakage of porcelain veneers ce mented on dentin margins. Methods. Forty human premolars were prepared on both the buccal and palatal surfaces. Each half was randomly assig ned to eight groups. The veneer preparation of one group was cut entir ely within enamel, to serve as controls. The remaining groups had cerv ical margins extending 1 mm beyond the cemento-enamel junction. Six de ntin bonding agents were tested. The specimens were subjected to therm ocycling and evaluated for marginal leakage using a silver nitrate sta in technique. After sectioning, the extent of microleakage was measure d at four interfaces: (1) incisal porcelain-composite; (2) incisal too th-composite; (3) cervical porcelain-composite; and (4) cervical tooth -composite. Results. Statistical analysis showed that the cervical too th-composite interface had a significantly higher leakage value (p<0.0 5) than the other three interfaces when the cervical margins were in d entin. Significance. The dentin bonding agents tested did not signific antly reduce the marginal leakage of the porcelain veneers cemented on dentin margins.