The bactericidal effects of an acidified sodium chlorite-containing oral moisturizing gel: a pilot study

The aim of this study was to examine the bactericidal effects and bactericidal time of an acidified sodium chlorite compound gel (ASC-Gel) on bacteria isolated from the peri-implant sulci of 10 patients who received implants 3-27 years previously, and the depth of each peri-implant sulcus was 5 mm or less. Porphyromonas gingivalis (ATCC33277) was used as the control bacterium. Five ASC-Gel preparations were created by adding 3.3%, 5.0%, 7.0%, 9.0%, and 11.0% citric acid (CA) (condition a, b, c, d, and e, respectively) into an oral moisturizing gel containing sodium chlorite. The concentrations of chlorine dioxide (ClO2) generated in ASC-Gel under conditions (a) to (e) were 12.1, 14.1, 17.2, 21.2, and 39.3 ppm, respectively. We examined the bactericidal effects of the 5 ASC-Gel preparations at volumes of 0.5, 1.0, and 2.0 mL, and measured the bactericidal time when 2.0 mL of ASC-Gel was used under condition (e). The bactericidal effects of ASC-Gel became significantly greater with increased concentrations of CA and ClO2 and with increased usage (0.5-2.0 mL) of the gel. All bacteria were killed by using 2.0 mL of ASC-Gel under condition (e). ASC-Gel also needed between 45 and 90 minutes to kill all microbes under condition (e). Within the limits of the present investigation, these results suggest that ASC-Gel is useful as a chemical disinfectant against bacteria in the peri-implant sulcus. Further studies are also required to protect teeth, the surface of hydroxyapatite-coated implants, and the surrounding soft tissues from effects of chemical dissolution such as acid erosion due to the low pH of ASC-Gel.