Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 6 1 2009 03 15 16 22 F. Darabi 1Assistant Professor, Department of Operative Dentistry, School of Dentistry, Guilan University of M M. Eftekhari Dentist, Private Practice 2015 10 03  Objective: The aim of this study was to evaluate the effect of concepsis (a chlorhexidine gluconate based cavity disinfectant) application on composite restorations micro leakage, using two adhesive systems: Excite and Adhese. Materials and Methods: In this interventional experimental study, class V cavities were prepared on buccal surfaces of seventy-two extracted bovine incisors. The specimens were randomly divided into 6 groups (n=12): A1: Acid Eching (AE), Excite; A2: AE, Concepsis, blot drying, Excite; A3: AE, Concepsis, water rinsing, Excite; B1: AE (only enamel margin), Adhese; B2: AE (only enamel margin), Concepsis, blot drying, Adhese; B3: AE (only enamel margin), Concepsis, water ringsing, Adhese. Afterwards, the cavities were restored with tetric Ceram composite, thermo-cycled (5 to 50°C, dwell time: 30s, 1000 cycles,), immersed in 0.5% methylen blue for 24 hours and the dye penetration was evaluated and scored on a scale on 0 to 4 under stereomicroscope (×30). The data were analyzed using Kruskal-Wallis and Multiple Comparison tests. Results: The only statistically significant difference was found between groups B1 and B2 at both occlusal and gingival margins. (P<0.05) Conclusion: Rinsing off the cavity disinfectant (Concepsis) before the bonding procedure does not affect the seal at the resin-tooth interface when using either of the adhesive systems; however, the sealing ability of Adhese seems to be inhibited by the remnants of the disinfecting agent. https://fid.tums.ac.ir/index.php/fid/article/view/173 https://fid.tums.ac.ir/index.php/fid/article/download/173/173