Demineralization prevention with a new antibacterial restorative composite containing QASi nanoparticles: an in situ study

Objectives To investigate whether a newly developed dental composite with quaternary ammonium silica dioxide (QASi) nanoparticles incorporated with other fillers into the restorative material demonstrates antibacterial activity by reducing enamel demineralization in an in situ gap model. Materials and methods Twenty subjects wearing a lower removable partial denture (RPD) with acrylic flanges on both sides of the mouth were recruited into the 4-week in situ study. The gap model consisted of an enamel slab placed next to a composite, separated by a 38-mu m space. In the split-mouth design on one side of the RPD, the composite was the Nobio Infinix composite (Nobio Ltd., Kadima, Israel), and the contralateral side used a control composite. Each participant received enamel slabs from one tooth. The gap model was recessed into the RPD buccal flange, allowing microbial plaque to accumulate within the gap. After 4 weeks of continuous wearing, decalcification ( increment Z mineral loss) of the enamel slabs adjacent to the gap was determined by cross-sectional microhardness testing in the laboratory. Results The increment Z for the antibacterial composite test side was 235 +/- 354 (mean +/- standard deviation [SD]; data reported from 17 participants) and statistically significantly lower compared to increment Z of the control side (774 +/- 556; mean +/- SD) (paired t-test, P<0.0001; mean of test minus control -539 (SD=392), 95% confidence interval of difference: -741, -338). Conclusions This in situ clinical study showed that composites with QASi antibacterial particles significantly reduced demineralization in enamel adjacent to a 38-mu m gap over a 4-week period in comparison to a conventional composite.

Automated summary

The study investigated the antibacterial activity of a newly developed dental composite with QASi nanoparticles. Results showed that this composite significantly reduced demineralization in enamel adjacent to a 38-mu m gap over a 4-week period compared to a conventional composite.