Quantitative Assessment of Primary Colonizer Adhesion on Different Resin-Based Restorative Materials Using SYBR Green qPCR

Background/Objectives: The aim of this study was to investigate primary colonizers adhering to the oral biofilm on five adhesive restorative materials. Methods: For each material (Admira Fusion, Clearfil AP-X, Durafill VS, Filtek Supreme XTE, and Venus Diamond), sixteen test specimens were prepared according to a standardized protocol. For pellicle formation, the specimens were incubated for two hours at 37 °C with sterile-filtered inactivated human saliva. The bacteria (Streptococcus oralis (S. oralis), Streptococcus gordonii (S. gordonii), Streptococcus sanguinis (S. sanguinis), Streptococcus mitis (S. mitis), and Actinomyces naeslundii (A. naeslundii)) were cultivated and suspended. A bacteria mix was prepared from the suspensions. The specimens with pellicles were wetted with the bacterial mix and incubated at 37 °C for 8 h. The total genomic DNA of the adhered bacteria was isolated and subsequently quantified using SYBR Green qPCR. Results: For S. gordonii, S. oralis, and A. spp., no significant differences in the amount of adhered bacterial DNA were found between the different materials. S. mitis DNA concentration was significantly higher on Filtek Supreme XTE compared to the other materials. Significantly higher DNA concentrations of S. sanguinis could also be detected on Filtek Supreme XTE compared to Clearfil AP-AX and Durafill VS. Conclusions: The investigated restorative materials showed species-specific differences in bacterial adhesion, with Filtek Supreme XTE exhibiting higher adhesion of S. mitis and S. sanguinis, whereas no differences were observed for the other tested species.