Different sealing materials preventing the microbial leakage into the screw‐retained implant restorations: anin vitroanalysis byDNA checkerboard hybridization

Abstract Objectives The aim of this controlled in vitro study was to identify and quantify up to 38 microbial species penetrating through the screw‐retained implant prostheses with different sealing materials. Material and methods Sixty morse cone implants were restored with single‐unit screw‐retained prostheses. All the components were randomly divided into five groups ( n = 12) according to the proposed materials: (1) polytetrafluoroethylene tape+composite resin; (2) polytetrafluoroethylene tape+gutta‐percha; (3) polytetrafluoroethylene tape+light‐polymerized provisional composite; (4) cotton pellet+gutta‐percha; and (5) cotton pellet+light‐polymerized provisional composite. Human saliva was used as contaminant media, and DNA checkerboard hybridization was used to identify and quantify microbial species. Results Microbial leakage was observed in all groups: M. salivarium , S. pasteuri , P. nigrescens , and P. melaninogenica were the species presenting the highest values of genome count, prevalence, and proportion within the groups. The total microbial mean counts (×10 5 , ± SD ) were as follows: Group 1 (2.81 ± 0.38), Group 2 (3.41 ± 0.38), Group 3 (6.02 ± 1.48), Group 4 (6.40 ± 1.42), and Group 5 (17.45 ± 1.67). Group 5 showed the higher microbial counts ( P < 0.001). Conclusions Moderate to high counts of pathogenic/nonpathogenic species were detected in the inner parts of implants from all groups. The lowest values of microbial counts were recorded for polytetrafluoroethylene tape associated with composite resin or gutta‐percha; cotton pellet associated with light‐polymerized provisional composite presented the highest microbial counts.