BACKGROUND AND OBJECTIVE: The matrix metalloproteinase plays a significant role in the bonding stability of the composite-tooth. Chlorhexidine has been offered as matrix metalloproteinase inhibitor in current years. The aim of this study was to investigation of effect of 2% chlorhexidine on enamel microleakage of composite fillings in different bonding systems.
METHODS: In this in vitro study, class V cavities were prepared on the lingual and buccal surface of forty extracted molar teeth. The cavities were etched and divided randomly to 8 groups: 1: Adper single Bond 2 (ASB), 2: Clearfil SE Bond (CSE), 3: Clearfil S3 Bond (CS3), 4: Single Bond Universal (SBU), 5: ASB + 2% Chlorhexidine (CHX), 6: CSE +2%CHX, 7: CS3 +2% CHX, 8: SBU + 2%CHX. After bonding application, the cavities were restored with Z250 composite and thermocycling procedure (5 to 55 C, 5000 cycles) was done. Enamel microleakage was measured by dye penetration test. The teeth were sectioned buccolingually and microleakage was recorded based on a 0‒3 scoring system under a stereomicroscope (Motic Micro Optic, industrial group Co, LTD, Japan) at 40x magnification. Data analysis was done.
FINDINGS: In ASB, CSE, CS3 and SBU bonding systems, Percent of samples without microleakage before use CHX was 80%, 90%, 90%and 80% and after it was 100%, 80%, 80% and 90 % respectively.
CONCLUSION: Use of 2% chlorhexidine has not adverse effect on enamel microleakage of composite restorations in different bonding systems.