Bacterial microleakage of a bioactive pit & fissure sealant. An in vitro evaluation

摘要

Purpose: To compare the sealing properties of three pit and fissure (P&F) sealants, Embrace Wet Bond (EWB), a bioactive P&F sealant Embrace Wet Bond through the addition of modified calcium phosphate (MCP) (EWBMCP) and ClinPro (CLPR). The sealing properties of the materials were tested by means of a bacterial microleakage test. Methods: 30 extracted intact human third molars were randomly assigned to three groups of 10 (n=10) teeth each. The teeth were cleaned with two passes of air abrasion, followed by rinsing for 20 seconds and then dried with compressed air for another 20 seconds leaving the enamel surface slightly moist. The coronal portion of each tooth was sectioned perpendicular to the long axis at the level of 4 mm below the top of the central fossa of the enamel. A parallel vertical channel 1 mm in diameter was prepared in the central fossa through the entire sample. All samples were sterilized with Gamma radiation. After etching the occlusal surface with 35% phosphoric acid gel followed by rinsing, the sealants were applied. The samples were stored at 37 degrees C in SPB for 3 weeks, thermal cycled for 2,000x (5-55 degrees C) and coated with nail varnish leaving 1 mm uncovered around the P&F material. Samples were then tested for microleakage of E. faecalis culture using a dual chamber leakage model. The broth in the lower chamber was checked daily for turbidity up to 90 days. Statistical significance was determined at P<0.05. Results: The median survival time for EWBMCP was significantly higher (P<0.05) than for EWB and CLPR. With respect to bacterial microleakage frequency, EWBMCP and CLPR behaved significantly better than EWB. The bioactive sealant EWBMCP outperformed the other two tested sealants in terms of resistance to bacterial microleakage. Long-term clinical studies are recommended to confirm these in vitro findings.