Denture disinfection using Salvia officinalis L: microbial load and selected properties of PMMA

ABSTRACT

Denture use may aggravate the occurrence of oral infections, considering it enhances microbial adherence. Aim: This study assessed the reduction of microbial loads of Candida albicans, Staphylococcus aureus, and Klebsiella oxytoca by disinfecting the polymethylmethacrylate (PMMA) of complete dentures with hydroalcoholic extract of Salvia officinalis. Additionally, the effect of such extract on the properties of PMMA was examined. Methods: Microorganisms were isolated from saliva samples collected from complete denture wearers. The hydroalcoholic extract of S. officinalis was produced according to the Brazilian Pharmacopoeia 5. The PMMA specimens (n=188) were immersed in microbial inoculum and incubated at 37°C for 16 hours per day. Then, they were subjected to a disinfection protocol for 30 days. The specimens were divided into five treatment groups sterile saline solution (0.85%; control), 0.2% chlorhexidine digluconate, and hydroalcoholic extract of S. officinalis (0.2%, 0.8%, and 1.16%). Microorganism adherence to the PMMA surface was also assessed, as well as surface roughness (Ra in µm) and color stability of the PMMA (mean ΔE). Changes in microbial load and surface roughness after the disinfection protocol were verified with paired t-test. Substances at day 10, adherence, and color stability were compared by the Kruskall-Wallis and Mann-Whitney tests, and one-way ANOVA was used to compare substances at the beginning and end of the experiment (α=0.05). Results: The 1.16% S. officinalis extract significantly reduced the microbial load of all the microorganisms after 30 days of disinfection (p<0.05). The microbial load of K. oxytoca was also reduced at lower concentrations of the S. officinalis extract (0.2% and 0.8%) (p<0.02). Antimicrobial and anti-adherent effects against microorganisms isolated from the oral cavity were observed. There was no significant change in surface roughness (p>0.05) and color stability was significantly higher in the control group (p<0.0001). Conclusions: The hydroalcoholic extract of S. officinalis may be used as a disinfectant solution for dentures