Effect of local hygiene protocols on denture-related stomatitis, biofilm, microbial load, and odor: A randomized controlled trial.

STATEMENT OF PROBLEM: Denture stomatitis affects complete denture wearers and is frequently treated with antifungals drugs, as well as treating the denture with sodium hypochlorite. Whether the limitations of these treatments can be overcome with local hygiene protocols that do not damage the denture materials or adversely affect the patient is unclear. PURPOSE: The purpose of this randomized controlled trial was to evaluate the effect of denture hygiene protocols on complete denture wearers with denture stomatitis. MATERIAL AND METHODS: For this randomized, double-blind controlled clinical trial, 108 participants were assigned to parallel groups: 0.25% sodium hypochlorite (positive control) 0.15% Triclosan, denture cleaning tablets, or denture cleaning tablets plus gingival cleaning tablets. The participants were instructed to brush the dentures and the palate and immerse the denture in the solutions. The outcomes of denture stomatitis remission, biofilm removal, decrease of microbial load (colony-forming units), and odor level of the mouth and denture were measured at baseline and after 10 days. Descriptive analyses were used for sociodemographic characterization of the participants; the Pearson chi-square test was used to compare participant frequency with different degrees of denture stomatitis. The data were not normally distributed (Shapiro-Wilks test) or homogeneous (Levene test). So, the Kruskal-Wallis and Dunn post hoc tests and Wilcoxon test were used to compare the effects of solutions and time on the variables (α=.05). RESULTS: The frequency of the highest to lowest denture stomatitis scores was significantly different for the 0.15% Triclosan and denture cleaning tablets groups. No significant difference was found among the groups in terms of denture stomatitis scores, biofilm, or colony-forming unit count of Candida spp. or C. albicans and S. mutans; a significant reduction was found in these parameters. The 0.25% sodium hypochlorite and 0.15% Triclosan treatments caused a significant reduction in Gram-negative microorganisms; these 2 protocols, and the denture cleaning tablets showed a significant reduction in Staphylococcus spp.; all protocols had similar effects. Only the S. mutans count of the palate decreased after 10 days. The odor level of the mouth and the denture was not significantly different (P=.778). CONCLUSIONS: The evaluated protocols can be recommended for the hygiene of complete dentures, since they were effective for all the variables studied.

Effectiveness of Oil-Based Denture Dentifrices-Organoleptic Characteristics, Physicochemical Properties and Antimicrobial Action.

Denture dentifrices must be effective and not deleterious to prosthetic devices. This study formulated and evaluated dentifrices based on oils of Copaifera officinalis, Eucalyptus citriodora, Melaleuca alternifolia, Pinus strobus, and Ricinus communis. Organoleptic characteristics (appearance, color, odor, taste), physicochemical properties (pH, density, consistency, rheological, abrasiveness, weight loss, and surface roughness) and antimicrobial (Hole-Plate Diffusion-HPD)/anti-biofilm (Colony Forming Units-CFU) action against Staphylococcus aureus, Streptococcus mutans, and Candida albicans were evaluated. Formulations were compared with water (negative control) and a commercial dentifrice (positive control). The data were analyzed by Kruskal-Wallis and Dunn tests (α = 0.05). The organoleptic and physicochemical properties were adequate. All dentifrices promoted weight losses, with high values for C. officinalis and R. communis, and an increase in surface roughness, without differing from each other. For antimicrobial action, C. officinalis and E. citriodora dentifrices were similar to positive control showing effectiveness against S. mutans and C. albicans and no dentifrice was effective against S. aureus; regarding the anti-biofilm action, the dentifrices were not effective, showing higher CFU counts than positive control for all microorganisms. The dentifrices presented satisfactory properties; and, although they showed antimicrobial action when evaluated by HPD, they showed no effective anti-biofilm action on multispecies biofilm.

Bacteriophage Cocktail-Mediated Inhibition of Pseudomonas aeruginosa Biofilm on Endotracheal Tube Surface.

Although different strategies to control biofilm formation on endotracheal tubes have been proposed, there are scarce scientific data on applying phages for both removing and preventing Pseudomonas aeruginosa biofilms on the device surface. Here, the anti-biofilm capacity of five bacteriophages was evaluated by a high content screening assay. We observed that biofilms were significantly reduced after phage treatment, especially in multidrug-resistant strains. Considering the anti-biofilm screens, two phages were selected as cocktail components, and the cocktail's ability to prevent colonization of the endotracheal tube surface was tested in a dynamic biofilm model. Phage-coated tubes were challenged with different P. aeruginosa strains. The biofilm growth was monitored from 24 to 168 h by colony forming unit counting, metabolic activity assessment, and biofilm morphology observation. The phage cocktail promoted differences of bacterial colonization; nonetheless, the action was strain dependent. Phage cocktail coating did not promote substantial changes in metabolic activity. Scanning electron microscopy revealed a higher concentration of biofilm cells in control, while tower-like structures could be observed on phage cocktail-coated tubes. These results demonstrate that with the development of new coating strategies, phage therapy has potential in controlling the endotracheal tube-associated biofilm.

Identification and Characterization of New Bacteriophages to Control Multidrug-Resistant Pseudomonas aeruginosa Biofilm on Endotracheal Tubes.

Studies involving antimicrobial-coated endotracheal tubes are scarce, and new approaches to control multidrug-resistant Pseudomonas aeruginosa biofilm on these devices should be investigated. In this study, five new P. aeruginosa bacteriophages from domestic sewage were isolated. All of them belong to the order Caudovirales, Myoviridae family. They are pH and heat stable and produce 27 to 46 particles after a latent period of 30 min at 37°C. Their dsDNA genome (ranging from ∼62 to ∼65 kb) encodes 65 to 89 different putative proteins. They exhibit a broad lytic spectrum and infect 69.7% of the P. aeruginosa strains tested. All the bacteriophages were able to reduce the growth of P. aeruginosa strains in planktonic form. The bacteriophages were also able to reduce the biofilm viability rates and the metabolic activity of P. aeruginosa strains in a model of biofilms associated with endotracheal tubes. In addition, scanning electron microscopy micrographs showed disrupted biofilms and cell debris after treatment of bacteriophages, revealing remarkable biofilm reduction. The lytic activity on multidrug-resistant P. aeruginosa biofilm indicates that the isolated bacteriophages might be considered as good candidates for therapeutic studies and for the application of bacteriophage-encoded products.

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

PURPOSE: To verify whether 0.1% and 0.2% sodium hypochlorite (NaOCl), 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; SH1, 0.1% NaOCl; SH2, 0.2% NaOCl 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: SH2 (MR=1.77) showed lower biofilm coverage; SH1 (MR = 2.37) and RC (MR = 2.74) presented intermediated values. RC (1.10 [0.96:1.75]) revealed higher colour alteration than SH1 (0.71 [0.62:0.80]) and SH2 (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% NaOCl showed the best clinical performance and did not cause adverse effects on acrylic resin on laboratory analyses.

Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study.

OBJECTIVE: Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. MATERIAL AND METHODS: Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5% significance level. RESULTS: Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. CONCLUSIONS: It may be concluded that 0.05% NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care.

Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study

OBJECTIVE: Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. MATERIAL AND METHODS: Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05 percent sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5 percent significance level. RESULTS: Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. CONCLUSIONS: It may be concluded that 0.05 percent NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care.

Effect of ageing and immersion in different beverages on properties of denture lining materials.

OBJECTIVES: To evaluate the color stability and hardness of two denture liners obtained by direct and indirect techniques, after thermal cycling and immersion in beverages that can cause staining of teeth. MATERIAL AND METHODS: Seventy disc-shaped specimens (18 x 3 mm) processed by direct (DT) and indirect techniques (IT) were made from Elite soft (n=35) and Kooliner (n=35) denture liners. For each material and technique, 10 specimens were subjected to thermal cycling (3,000 cycles) and 25 specimens were stored in water, coffee, tea, soda and red wine for 36 days. The values of color change, Shore A hardness (Elite soft) and Knoop hardness (Kooliner) were obtained. The data were subjected to ANOVA, Tukey's multiple-comparison test, and Kruskal-Wallis test (P<0.05). RESULTS: The thermal cycling promoted a decrease on hardness of Kooliner regardless of the technique used (Initial: 9.09± 1.61; Thermal cycling: 7.77± 1.47) and promoted an increase in the hardness in the DT for Elite Soft (Initial: 40.63± 1.07; Thermal cycling: 43.53± 1.03); hardness of Kooliner (DT: 8.76± 0.95; IT: 7.70± 1.62) and Elite Soft (DT: 42.75± 1.54; IT=39.30± 2.31) from the DT suffered an increase after the immersion in the beverages. The thermal cycling promoted color change only for Kooliner in the IT. Immersion in the beverages did not promote color change for Elite in both techniques. The control group of the DT of Kooliner showed a significant color change. Wine and coffee produced the greatest color change in the DT only for Elite Soft when compared to the other beverages. CONCLUSION: The three variation factors promoted alteration on hardness and color of the tested denture lining materials.

Effect of ageing and immersion in different beverages on properties of denture lining materials

OBJECTIVES: To evaluate the color stability and hardness of two denture liners obtained by direct and indirect techniques, after thermal cycling and immersion in beverages that can cause staining of teeth. MATERIAL AND METHODS: Seventy disc-shaped specimens (18 x 3 mm) processed by direct (DT) and indirect techniques (IT) were made from Elite soft (n=35) and Kooliner (n=35) denture liners. For each material and technique, 10 specimens were subjected to thermal cycling (3,000 cycles) and 25 specimens were stored in water, coffee, tea, soda and red wine for 36 days. The values of color change, Shore A hardness (Elite soft) and Knoop hardness (Kooliner) were obtained. The data were subjected to ANOVA, Tukey's multiple-comparison test, and Kruskal-Wallis test (P<0.05). RESULTS: The thermal cycling promoted a decrease on hardness of Kooliner regardless of the technique used (Initial: 9.09± 1.61; Thermal cycling: 7.77± 1.47) and promoted an increase in the hardness in the DT for Elite Soft (Initial: 40.63± 1.07; Thermal cycling: 43.53± 1.03); hardness of Kooliner (DT: 8.76± 0.95; IT: 7.70± 1.62) and Elite Soft (DT: 42.75± 1.54; IT=39.30± 2.31) from the DT suffered an increase after the immersion in the beverages. The thermal cycling promoted color change only for Kooliner in the IT. Immersion in the beverages did not promote color change for Elite in both techniques. The control group of the DT of Kooliner showed a significant color change. Wine and coffee produced the greatest color change in the DT only for Elite Soft when compared to the other beverages. CONCLUSION: The three variation factors promoted alteration on hardness and color of the tested denture lining materials.

Domestic use of a disclosing solution for denture hygiene: a randomised trial.

OBJECTIVES: The purpose of this study was to investigate the effect of the domestic use of a disclosing agent for denture hygiene. MATERIALS AND METHODS: Completely edentulous participants wearing maxillary dentures were randomly assigned to one of the three intervention groups: (1) Follow-up only (control; n = 12); (2) Oral and denture hygiene instructions (n = 10); (3) Instructions associated with the home use of a disclosing agent (1% neutral red; n = 10). Biofilm coverage area (%) over internal and external surfaces of the maxillary denture was assessed at baseline and after 14 and 90 days. Data were evaluated by generalised estimating equations based on score tests (alpha = 0.05). RESULTS: The participants presented low changes for areas of biofilm coverage (14 days (%): internal: GI = 1.4 +/- 0.9; GII = 1.5 +/- 1.3; GIII = -0.4 +/- 0.9; external: GI = 1.4 +/- 1.5; GII = 1.5 +/- 1.4; GIII = -0.4 +/- 0.9; 90 days (%): internal: GI = 2.0 +/- 0.9; GII = 2.2 +/- 1.4; GIII = 0.3 +/- 1.0; external: GI = 2.1 +/- 1.4; GII = 2.2 +/- 1.5; GIII = 0.3 +/- 0.9). Changes were similar for the three groups (p = 0.293) and were not influenced by the test time (p = 0.218). CONCLUSION: It can be concluded that the home use of a disclosing agent for denture hygiene does not improve the removal of the biofilm, particularly for patients with adequate oral hygiene habits.

Mass loss of four commercially available heat-polymerized acrylic resins after toothbrushing with three different dentifrices

The association between a toothbrush and a dentifrice is the most used denture cleaning method. The purpose of this study was to evaluate the abrasiveness of specific and non-specific denture cleaning dentifrices on different heat-polymerized acrylic resins. Sixteen specimens (90x30x3mm) of each acrylic resin (QC-20, Lucitone 550, Clássico, Vipi-Cril) were prepared and randomly assigned to 4 groups: 1: control (distilled water), 2: Colgate, 3: Bonyplus and 4: Dentu-Creme. The specimens were subjected to simulated toothbrushing in an automatic brushing machine using 35,600 brush strokes for each specimen. Brushing abrasion run at a 200-g load with the specimens immersed in 2:1 dentifrice/water slurry. Specimens were reconditioned to constant mass and the mass loss (mg) was evaluated. Data were analyzed by 2-way ANOVA and Tukey's test (a=0.05). Analysis of dentifrices' abrasive particles was made by scanning electron microscopy. Colgate produced the greatest mass reduction (42.44 mg, p<0.05), followed by Dentu-Creme (33.60 mg). Bonyplus was the less abrasive (19.91 mg), similar to the control group (19.69 mg) (p>0.05). The mass loss values indicated that QC-20 (33.13 mg) and Lucitone 550 (33.05 mg) resins were less (p<0.05) resistant to abrasion than Clássico (26.04 mg) and Vipi-Cril (23.43 mg). In conclusion, Colgate produced the greatest abrasion. Specific dentifrices for dentures tend to cause less damage to acrylic resins.

Mass loss of four commercially available heat-polymerized acrylic resins after toothbrushing with three different dentifrices.

The association between a toothbrush and a dentifrice is the most used denture cleaning method. The purpose of this study was to evaluate the abrasiveness of specific and non-specific denture cleaning dentifrices on different heat-polymerized acrylic resins. Sixteen specimens (90 x 30 x 3 mm) of each acrylic resin (QC-20, Lucitone 550, Clássico, Vipi-Cril) were prepared and randomly assigned to 4 groups: 1: control (distilled water), 2: Colgate, 3: Bonyplus and 4: Dentu-Creme. The specimens were subjected to simulated toothbrushing in an automatic brushing machine using 35,600 brush strokes for each specimen. Brushing abrasion run at a 200-g load with the specimens immersed in 2:1 dentifrice/water slurry. Specimens were reconditioned to constant mass and the mass loss (mg) was evaluated. Data were analyzed by 2-way ANOVA and Tukey's test (a=0.05). Analysis of dentifrices' abrasive particles was made by scanning electron microscopy. Colgate produced the greatest mass reduction (42.44 mg, p<0.05), followed by Dentu-Creme (33.60 mg). Bonyplus was the less abrasive (19.91 mg), similar to the control group (19.69 mg) (p>0.05). The mass loss values indicated that QC-20 (33.13 mg) and Lucitone 550 (33.05 mg) resins were less (p<0.05) resistant to abrasion than Clássico (26.04 mg) and Vipi-Cril (23.43 mg). In conclusion, Colgate produced the greatest abrasion. Specific dentifrices for dentures tend to cause less damage to acrylic resins.