Evaluation of biofilm removal and adverse effects on acrylic resin by diluted concentrations of sodium hypochlorite and Ricinus communis Ricinus communis solutions

摘要

Purpose To verify whether 0.1% and 0.2% sodium hypochlorite (Na OC l), and 8% Ricinus communis ( RC ) were able to remove denture biofilm without causing deleterious effects to acrylic resin. Background Previous data show that denture cleansers are effective in reducing biofilm; however, they can change acrylic resin properties. Methods In a crossover trial, 47 denture wearers brushed and soaked their dentures (20?min/14?d): control, 0.85% saline; SH 1, 0.1% Na OC l; SH 2, 0.2% Na OC l and RC . Denture biofilm on the intaglio surface was stained, photographed and quantified (Image Tool ? ). Furthermore, 80 rectangular and 80 disc‐shaped specimens (Lucitone 550) were assigned into tested solutions (n?=?20), simulating 5?years of daily short immersions (20?minutes). A colorimeter and the National Bureau of Standards units ( NBS ) determined colour data (ΔE). Surface roughness and flexural strength were measured using rugosimeter and universal testing machine, respectively. Data were compared by the Friedman test (α?=?.05) followed by Wilcoxon, corrected by Bonferroni (α?=?.005) (clinical) and Kruskal‐Wallis followed by the Dunn test (α?=?.05) (laboratorial). Results SH 2 ( MR =1.77) showed lower biofilm coverage; SH 1 ( MR = 2.37) and RC ( MR = 2.74) presented intermediated values. RC (1.10 [0.96:1.75]) revealed higher colour alteration than SH 1 (0.71 [0.62:0.80]) and SH 2 (0.74 [0.58:0.85]); however, NBS classified all solutions as “trace” (0.0‐0.5). There was no statistical significance for surface roughness ( P ?=?.760) and flexural strength ( P ?=?.547). Conclusions The 0.2% Na OC l showed the best clinical performance and did not cause adverse effects on acrylic resin on laboratory analyses.