Efficacy of Denture Cleansers on Microbial Adherence and Surface Topography of Conventional and CAD/CAM-Processed Denture Base Resins

Abstract

This study assessed the efficacy of five denture cleansers on the microbial adherence and surface topography of conventional and CAD/CAM denture base resins. Acrylic resin discs were fabricated using conventional, milling, and 3D printing methods (N = 180). The discs were contaminated with dual species of Candida albicans and Streptococcus mutans biofilm for 72 h and then disinfected with either of the denture cleansers (Fittydent cleansing tablets, 2% Chlorhexidine gluconate, 0.2% Chlorhexidine gluconate, 0.5% sodium hypochlorite, and 1% sodium hypochlorite (n = 10). Distilled water served as the control group. The colony-forming units of the microorganisms were calculated, followed by post-treatment surface roughness. Data were statistically analyzed using one-way ANOVA, paired t-test, and post hoc Tukey HSD test (α = 0.05). Among the denture cleansers, 2% Chlorhexidine gluconate, 0.5% sodium hypochlorite, and 1% sodium hypochlorite had the best cleansing effect on the resin discs and demonstrated zero growth of colonies for both the species. Comparing the material groups, the 3D-processed discs showed higher colony-forming units followed by the conventional and CAD/CAM milled group. The highest surface roughness was demonstrated by the 3D-printed discs (0.690 ± 0.08 μm), followed by the conventional (0.493 ± 0.11 μm) and the milled groups (0.301 ± 0.08 μm). The tested chemical denture cleansers affected the Candida albicans and Streptococcus mutans adhesion compared to control discs immersed in distilled water. The clinician may recommend to their patient to use 2% chlorhexidine gluconate for the disinfection of CAD/CAM PMMA denture base materials.

Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial

“… 25 This concentration and exposure time were selected based on the antimicrobial effectiveness demonstrated by in vitro and in vivo studies on denture disinfection after a single cycle of immersion of denture base materials (or complete denture) for 10 min. 17 , 18 , 19 , 23 Unlike the results obtained in this trial, Pellizzaro, et al 24 (2012) reported greater antimicrobial effectiveness when immersion in 1% sodium hypochlorite was associated with brushing acrylic resin specimens. Such differences can be attributed to the fact that the study was carried out under in vitro conditions with a biofilm of a single microbial species and to the shorter immersion time than that used in this investigation.…”

“…The selection of concentrations, immersion time, and brushing protocols used with chlorhexidine solutions was carried out based on the antimicrobial effectiveness demonstrated by in vitro 15 , 17 , 18 , 20 , 22 , 24 , 27 and in vivo studies. 23 , 25 In this investigation, brushing with 2% chlorhexidine (BRU/CHX-2) proved as effective as protocols that used hypochlorite solution.…”

“…BRU+HYP : Brushing with distilled water for 2 min, 12 , 13 , 36 followed by immersion in 150 mL of 1% sodium hypochlorite for 10 min; 17 , 19 …”

“… 10 To overcome these limitations, brushing should be combined with microwave irradiation or immersion in chemical cleaning agents. 14 , 17 - 27 These protocols are ideally recommended as methods of denture disinfection in order to effectively and completely remove biofilm after one application. 26 Unlike home denture hygiene practices to control biofilm, which are used daily by denture wearers, 28 such cleaning protocols are recommended for short periods of time 23 , including the patient’s stay in a hospital.…”

“…Denture cleaning protocols using solutions of 1% sodium hypochlorite, 2% chlorhexidine digluconate and alkaline peroxide, as well as microwave irradiation at 650 W demonstrated in vivo and in vitro antimicrobial effectiveness on denture base materials, even after a single application. 14 , 17 - 27 Furthermore, such protocols, after successive application cycles, are unable to adversely affect the physical and mechanical properties of denture base materials 17 , 29 - 31 and acrylic artificial teeth. 32 - 34 …”