Objectives: This in vitro study was conducted to investigate the effect of dentin bonding agents on the microleakage of porcelain veneers cemented on dentin margins.
Methods: Forty human premolars were prepared on both the buccal and palatal surfaces. Each half was randomly assigned to eight groups. The veneer preparation of one group was cut entirely within enamel, to serve as controls. The remaining groups had cervical margins extending 1 mm beyond the cemento-enamel junction. Six dentin bonding agents were tested. The specimens were subjected to thermocycling and evaluated for marginal leakage using a silver nitrate stain technique. After sectioning, the extent of microleakage was measured at four interfaces: (1) incisal porcelain-composite; (2) incisal tooth-composite; (3) cervical porcelain-composite; and (4) cervical tooth-composite.
Results: Statistical analysis showed that the cervical tooth-composite interface had a significantly higher leakage value (p < 0.05) than the other three interfaces when the cervical margins were in dentin.
Significance: The dentin bonding agents tested did not significantly reduce the marginal leakage of the porcelain veneers cemented on dentin margins.