In vitro evaluation of two adhesive systems used with compomer filling materials

Aim: To evaluate and compare the in-vitro shear bond strength, micro-leakag e and dentine-restorative interface of a self-etching/self-priming dentine bonding agent with a three-component dentine-bonding agent. Method: For she ar bond strength (SBS) testing 30 non-carious human molars were used of whi ch 15 were tested with Non-Rinse Conditioner (NRC)/Prikme&Bond NT (PBNT) an d Dyract AP and 15 were tested with Scotchbond Multi-Purpose Plus (SBMP) an d F2000. For the microleakage evaluation cavity preparations were made on t he facial surfaces of 30 non-carious human premolars of which 15 were resto red with NRC and PENT with Dyract AP and 15 were restored with SBMP and F20 00. The dentine-restorative interface was examined through a confocal scann ing laser microscope (CSLM). Results: The mean SBS of PENT and SBMP were 12 .8 and 18.1 MPa, respectively. The microleakage scores showed NRC/PBNT leak ed on the dentine side in 13 of the 15 specimens examined. On the enamel si de two of the 15 specimens showed microleakage. With SBMP no microleakage w as observed on either enamel or dentine sides. The CSLM images show clear r esin tag and hybrid layer formation for both the materials examined althoug h SBMP showed better and deeper penetration into the dentine with longer re sin tags. SBMP showed resin tags measuring about 150mm while the hybrid lay er measured about 5mm. The length of the resin tags as well as the thicknes s of the hybrid layer for PENT were pound 20mm and pound 2mm, respectively. Conclusions: The acid-etch technique of SBMP produced higher bond strength and no microleakage when compared with the self-etching/self-priming 'non- rinse technique' of NRC with PENT. Thus it can only be speculated that SBMP should be the superior in the clinical situation.