The Antimicrobial Effect of a Copper-Containing Sealant

Sealants protect the pit and fissure areas of teeth surfaces by penetrating into the fissures of the tooth sealing them from additional bacterial colonization, and to isolate existing sealed bacteria from nutrient sources derived from the oral environment. Copper salts have antimicrobial properties and have been previously used in dentistry to control microbial growth adjacent to copper releasing dental materials. Objective: to evaluate the antimicrobial property of a new sealant material containing copper silver colloid (C.I. Seal; Cooley and Cooley) compared to a non-copper resin sealant (Pit and Fissure sealant; Delton). Methods: Cylindrical specimens (2 x 3 mm) were prepared of each type of sealant material and were then individually sterilized using ethylene oxide gas. Mitis Salivarius agar plates supplemented with bacitracin and sucrose were inoculated with 0.5 ml of an overnight culture of Streptococcus mutans TH16 (serotype c) which was evenly spread on each of the plates. One specimen was then placed on each of the plates with sterile forceps and each plate was incubated at 37^oC in 5% CO₂ for 48 hours. Plates were then examined for an inhibition zone (no bacterial growth) surrounding each specimen, and the diameter of the inhibition zone was measured. Groups were compared using a Mann-Whitney Rank Sum Test due to unequality of variances. Results: C.I. Seal material developed a significantly larger (p<0.05) inhibition zone (mean±SD = 3.8±2.0; N=11) than did the control group (1.3±2.1; N=9). Conclusion: C.I. Seal material demonstrated a larger antimicrobial effect against S. mutans than did the non-copper control sealant. This study was supported by grants from IUSD and Cooley and Cooley.