Objective: The purpose of this investigation was to evaluate the microleaka
ge of Class V lesions restored with a compomer material (Dyractflow) using
2 single-bottle bonding systems. Method and materials: Sixty-four Class V c
avity preparations were made on 32 sound, extracted human premolars, 1 prep
aration on the facial surface and 1 on the lingual surface. Teeth were then
randomly divided into 2 groups. Group 1, which served as the control group
, was restored as follows: group la, facial surface with PQ1 single-bottle
bonding system plus TPH resin composite; group Ib, lingual surface with Pri
me & Bond NT single-bottle bonding system plus TPH. Group 2 was restored as
follows: group 2a, facial surface with PQ1 plus Dyractflow compomer materi
al; group 2b, lingual surface with Prime & Bond NT plus Dyractflow. After 2
4 hours of storage in water and subsequent thermocycling, each specimen was
immersed in 0.2% basic fuchsin dye for 24 hours. The teeth were sectioned
longitudinally and horizontally, and dye penetration at enamel and cementum
margins was viewed at x30 magnification by 2 independently calibrated eval
uators. Specimens were evaluated as either having leaked or not having leak
ed. Results: No statistically significant differences in microleakage were
noted between group 1 and group 2 specimens. Conclusion: Both single-bottle
bonding systems, PQ1 and Prime & Bond NT, demonstrated equal effectiveness
in reducing microleakage beneath compomer and composite restorations.