Effects of short-time exposure of surface pre-reacted glass-ionomer eluate on dental microcosm biofilm

Abstract

This study evaluated the antibacterial effects of short-time exposure of surface pre-reacted glassionomer (S-PRG) eluate on oral microcosm biofilm. Biofilms were treated with an S-PRG eluate at different concentrations (25%, 50%, and 100%), distilled water (DW), and 0.1% chlorhexidine (CHX) twice a day for 5 min repeatedly. After 7 days, the total and aciduric bacterial counts and biofilm dry weights were measured. An image analysis program calculated the red/green (R/G) ratios in the biofilm autofluorescence images. Microscopic analyses quantified the biofilm thickness and live/dead cell ratio and determined morphological changes in the biofilm. Bacterial counts and dry weights were not significantly different in the DW group for all S-PRG eluate concentrations. An increasing trend in the R/G ratio for 7 days biofilm treatment was observed for the S-PRG eluate and the DW groups. Furthermore, the live/dead cell ratios in the biofilm and the biofilm thickness of the S-PRG eluate groups were similar to those of the DW group. The bacteria morphology inside the biofilm changed only in the CHX group. Short-time S-PRG eluate treatment showed no significant antibacterial and antibiofilm effects. These results indicated that limited biofilm formation inhibition can be obtained by using only the S-PRG eluate. Dental caries is a major oral disorder caused by the pathogenic bacteria inhabiting complex microbial communities known as biofilms 1. Intraoral biofilms increase the resistance against planktonic bacteria and make it difficult for foreign substances to penetrate the extracellular matrix that forms a thick physical layer via an acquired pellicle stage 2. Physical interventions including toothbrushing and the use of dental chemicals containing effective antibacterial components have been proposed as self-management methods for removing these oral biofilms 3. Various antibacterial active ingredients are currently under development, and numerous studies have evaluated their effectiveness in preventing dental caries by examining the antibacterial and anticariogenic effects. Various recent studies have reported the remineralization and antibacterial activities of dental restorative materials constructed using a pre-reacted glass-ionomer (PRG) technology in combination with polymers 4. Surface pre-reacted glass-ionomer (S-PRG) filler is a material treated with a siliceous hydrogel that is formed via an acid-base reaction between fluoroboroaluminosilicate glass and polyacrylic acid.

Effects of Surface Prereacted Glass on Saliva-Derived Polymicrobial Biofilms in an Active Attachment Biofilm Model

“…Repeated treatments did not result in an increased efficacy, which may indicate that the retention of the eluent in the biofilm is low or that the rinsing steps (which are part of the treatment regime) effectively removed the eluent from the system. These findings are in line with results from Kim et al [2020] who found that twice-daily treatments with S-PRG eluate had no effect on biofilm viability. However, as these findings are in contrast to other publications [Yoneda et al, 2012;Suzuki et al, 2014;Shimazu et al, 2016;Nomura et al, 2018Nomura et al, , 2021 in which S-PRG eluate was tested while continuously present, S-PRG eluent was added to the growth medium in subsequent experiments.…”

“…These findings were in contrast to previous studies [Yoneda et al, 2012;Suzuki et al, 2014;Shimazu et al, 2016;Nomura et al, 2018Nomura et al, , 2021] that evaluated the effect of S-PRG on biofilm formation and bacterial growth. However, only one other study evaluated the effect of short-term exposure of oral biofilms to S-PRG eluate and found a comparable lack of efficiency [Kim et al, 2020].…”

Surface Modification of Pure Zinc by Acid Etching: Accelerating the Corrosion Rate and Enhancing Biocompatibility and Antibacterial Characteristics

“…After 1 day of biofilm development, the samples were washed thrice with PBS to remove unattached bacteria. According to the manufacturer’s instructions, the biofilms were stained with SYTO 9 and propidium iodide (LIVE/DEAD BacLight Bacterial Viability Kit) according to the manufacturer’s instructions . Briefly, the staining solution was prepared by adding 3.0 μL each of SYTO 9 and propidium iodide to 1 mL of PBS.…”

“…According to the manufacturer's instructions, the biofilms were stained with SYTO 9 and propidium iodide (LIVE/DEAD BacLight Bacterial Viability Kit) according to the manufacturer's instructions. 42 Briefly, the staining solution was prepared by adding 3.0 μL each of SYTO 9 and propidium iodide to 1 mL of PBS. The staining solution (600 μL) was added to each well and incubated in the dark at room temperature for 30 min.…”

Influence of Bioinspired Lithium-Doped Titanium Implants on Gingival Fibroblast Bioactivity and Biofilm Adhesion

“…Triplicate Ti samples were washed twice with phosphate-buffered saline (pH 7.2) at 24 and 72 h of culture before assessment of biofilm viability using a Filmtracer™ LIVE/DEAD™ Biofilm Viability Kit (Invitrogen, ThermoFisher Scientific, Scoresby, VIC, Australia) as previously described [46]. Following a 20 min incubation at room temperature (25 • C), the biofilms were washed once for removal of unbound stain and two-dimensional images of the biofilms captured using the confocal microscopy.…”