The Influence of Modified Experimental Dental Resin Composites on the Initial In Situ Biofilm-A Triple-Blinded, Randomized, Controlled Split-Mouth Trial

Abstract

The purpose of the study was to investigate the bacterial viability of the initial biofilm on the surface of experimental modified dental resin composites. Twenty-five healthy individuals with good oral hygiene were included in this study. In a split-mouth design, they received acrylic splints with five experimental composite resin specimens. Four of them were modified with either a novel polymeric hollow-bead delivery system or methacrylated polymerizable Irgasan (Antibacterial B), while one specimen served as an unmodified control (ST). A delivery system based on Poly-Pore^® was loaded with one of the active agents: Tego^® Protect 5000 (Antiadhesive A), Dimethicone (Antiadhesive B), or Irgasan (Antibacterial A). All study subjects refrained from toothbrushing during the study period. Specimens were detached from the splints after 8 h and given a live/dead staining before fluorescence microscopy. A Friedman test and a post hoc Nemenyi test were applied with a significance level at p < 0.05. In summary, all materials but Antibacterial B showed a significant antibacterial effect compared to ST. The results suggested the role of the materials' chemistry in the dominance of cell adhesion. In conclusion, dental resin composites with Poly-Pore-loaded active agents showed antibacterial effectiveness in situ.

Keywords: Poly-Pore; antiadhesive composites; antibacterial composites; bacterial viability; clinical trial; live/dead staining; split-mouth.

Figure 1

Custom-made removable acrylic splint: (a) specimens facing towards the buccal side of the first three approximal spaces of the posterior teeth; (b) placed onto a dental cast with the outward shielding element towards the cheeks and free space between the specimens and teeth, allowing salivatory flow.

Figure 2

Tukey box plots of vital, non-vital, and total bacteria cell count without outliers. Significant differences are bracketed with asterisks (*, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001).

Figure 3

Tukey box plots of BV without outliers. Significant differences are bracketed with asterisks (*, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001).

Figure 4

Comparison of representative superimposed fluorescence microscopic images (magnification 400-fold) of vital (green) and non-vital (red) bacterial cells from a single participant: (a) ST accumulated many vital and a few non-vital bacterial cells; (b) Antiadhesive A showed no vital but some non-vital bacterial microorganisms.