Color variations in PMMA acrylic resins after thermocycling and mouthwash simulation / Variações de cor em resinas acrílicas de PMMA após termociclagem e simulação de enxaguatório bucal

Estabilidade de cor é um requisito estético fundamental das resinas acrílicas provisórias, em especial quando esses materiais são submetidos a longos períodos na cavidade oral. Embora resinas acrílicas temporárias novas e aprimoradas estejam disponíveis, os efeitos da variação térmica e de soluções antissépticas na estabilidade de cor de resinas acrílicas provisórias ainda não foram completamente elucidados. Portanto, este estudo avaliou a coloração de resinas autopolimerizáveis polimetilmetacrilato (PMMA) e bis-acrilo submetidas à termociclagem e imersão em clorexidina. Amostras padronizadas (n=10) foram preparadas de duas resinas acrílicas temporárias a base de PMMA (Alike® e Duralay®). Foram realizadas três avaliações de cor (T1 ­ 24h após o preparo da amostra, T2 ­ após termociclagem e T3 ­ após termociclagem e imersão em clorexidina) por meio de espectrofotômetro eletrônico de seleção de sombra (Vita Easy Shade). Os dados obtidos foram analisados por ANOVA e teste t (α=0,05). As resinas de PMMA Alike e Duralay apresentaram alteração de cor após a termociclagem e também após a imersão em clorexidina.

Color stability is a fundamental aesthetic requirement for temporary acrylic resins, especially when these materials are subjected to long periods in the oral cavity. Although new and improved temporary acrylic resins are available, the effects of thermal variation and antiseptic solutions on the color stability of temporary acrylic resins have not yet been fully elucidated. Therefore, this study evaluated the color of self-polymerizing resins polymethyl methacrylate (PMMA) and bis-acryl subjected to thermocycling and immersion in chlorhexidine. Standardized samples (n=10) were prepared from two PMMA-based temporary acrylic resins (Alike® and Duralay®). Three color evaluations were carried out (T1 ­ 24h after sample preparation, T2 ­ after thermocycling and T3 ­ after thermocycling and immersion in chlorhexidine) using an electronic shade selection spectrophotometer (Vita Easy Shade). The data obtained were analyzed by ANOVA and t test (α=0.05). PMMA Alike and Duralay resins showed color changes after thermocycling and also after immersion in chlorhexidine.

Resveratrol alters oral biofilm in vitro and in vivo.

OBJECTIVE: To evaluate the ability of resveratrol to reduce dental caries in vitro and in vivo. METHODS: In part 1, a microcosm biofilm protocol was employed. One hundred twenty-six bovine enamel specimens were treated with: Resveratrol (50, 100, 200, 400 µg/mL), Phosphate buffered saline (negative control), Dimethyl sulfoxide (negative control) and 0.12% Chlorhexidine (positive control). The biofilm was produced from the saliva of 10 volunteers, under 0.2% sucrose exposure for 5 days, and daily treated with the solutions (1 min). At the end of the experimental period, resazurin and viable plate count assays were performed. Enamel demineralization was evaluated by transverse microrradiography (TMR). In part 2, 12 volunteers participated in a triple-blind crossover protocol for 7 weeks, according to the following treatments: 1) 100 mg/L resveratrol; 2) 0.05% NaF (226 mg/L F); 3) 100 mg/L resveratrol + 0.05% NaF; 4) Deionized water (negative control). Biofilm samples were collected from both sides of the mouth 12 h after the use of the solutions. RESULTS: Resveratrol at 50 and 200 µg/mL significantly reduced biofilm metabolic activity and mutans streptococci, respectively. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent in vitro. Resveratrol alone or associated with NaF modulated several caries-associated bacteria in vivo. CONCLUSION: The present study represents the first step regarding the use of resveratrol within the concept of acquired enamel pellicle and biofilm engineering to prevent dental caries.

Effect of final irrigation protocols on the structural integrity and mechanical properties of the root dentine.

This study compared the effects of different final irrigation protocols on the mechanical properties and structural integrity of root dentine. One-hundred eight teeth were instrumented and irrigated with sodium hypochlorite (NaOCl) using conventional irrigation (CI). Teeth were distributed into four groups based on final irrigation protocols: Control Group (CG): 17%EDTA/CI + H2O; G1: 2.5%NaOCl/Passive Ultrasonic Irrigation (PUI) + EDTA/PUI + NaOCl/PUI (60s each); G2: EDTA/PUI + NaOCl/PUI (30s each); G3: EDTA/PUI + NaOCl/PUI + H2O/PUI + CHX/PUI (30s each). Four tests were conducted: three-point flexural strength test, Scanning Electron Microscopy analysis, microhardness assessment, and the push-out bond strength (POBS) of the filling material to the root dentine. Data were analyzed using ANOVA and Tukey tests (Flexural strength), and Student t-test (Microhardness). Erosion scores and POBS were analyzed by Kruskal-Wallis and Dunn tests (α = 0.05). Results indicated no significant differences in flexural strength (p > 0.05) among groups. CG exhibited the lowest erosion scores in the cervical third. In the middle third, CG had lower scores than G1 and G2, while in the apical third, CG had lower scores than G1 (p < 0.05). Microhardness values decreased following the protocols (p < 0.05), except for the CG (p > 0.05). G2 displayed higher POBS values in the middle and apical thirds (p < 0.05). The protocols did not significantly influence the flexural strength of root dentine. However, they did affect microhardness and promoted greater erosion. The best results for POBS were observed when the final irrigation involved the sequential use of EDTA and NaOCl employing PUI for 30 seconds in each solution.

Antimicrobial activity of PMMA enriched with nano-clay loaded with metronidazole and chlorhexidine.

Poly(methyl methacrylate) (PMMA) materials are highly susceptible to microbial colonization, predisposing patients to oral infections. To address this concern, we loaded PMMA samples with montmorillonite clay (MMT), a crystalline nanoparticle, in combination with chlorhexidine (CHX) or metronidazole (MET) targeting improved antimicrobial action. PMMA samples were prepared with or without MMT loaded with either CHX or MET, establishing the following groups: control (acrylic resin without the addition of nanoparticles), MMT/CHX (acrylic resin with 5% by weight of MMT loaded with CHX), and MMT/MET (acrylic resin with 5% by weight of MMT loaded with MET). Mechanical properties such flexural strength, flexural modulus, and Knoop hardness were evaluated using a universal testing machine. Antimicrobial efficacy was assessed via agar diffusion tests against Enterococcus faecalis and Porphyromonas gingivalis. The addition of MMT loaded with CHX did not affect the flexural strength and flexural modulus of PMMA compared to the control group (p > 0.05). However, MMT/MET reduced all mechanical properties of PMMA (p < 0.05). Both loaded-PMMA materials demonstrated antibacterial activity against E. faecalis but not against P. gingivalis. In conclusion, the incorporation of MMT/CHX into acrylic resin appears to be the most promising approach to combat microbial colonization while preserving PMMA mechanical properties. Future research should focus on optimizing material characteristics to enhance antimicrobial properties, paving the way for clinical applicability.

Effect of chloramine T and chlorhexidine in reducing gingivitis in patients admitted to a reference hospital for cardiopulmonary care: a randomized, controlled clinical trial.

OBJECTIVE: The aim of this study is to evaluate the effect of Chloramine T in reducing gingivitis in hospitalized patients, in addition to providing an alternative to the use of Chlorhexidine. MATERIALS AND METHODS: A randomized, triple-blind, placebo controlled clinical trial was performed with 45 volunteers presenting with gingivitis, using the Löe Gingival Index (LGI). Patients were randomly allocated into one of three groups: (G1): Chloramine T 0.2%; (G2): Chlorhexidine 0.12% and (G3): distilled water. RESULTS: After five days, the control group (G3) remained without relevant differences in relation to the first pre-treatment assessment, while the groups tested with chlorhexidine and chloramine T showed improvement in the LGI (p < 0.05). After ten days, G3 maintained the results of the previous assessments, G1 repeated the five-day assessment and G2 obtained a statistically significant difference, with a better result in relation to the previous assessment (p < 0.05). After fifteen days, G3 showed no differences in relation to the other assessments, G1 had a statistically significant difference, showing better performance in relation to the previous assessment and G2 continued the gradual improvement it had been showing in the LGI (p < 0.05). CONCLUSIONS: Chloramine T and Chlorhexidine present similar results in the treatment of gingivitis, when evaluated by probing by the LGI, and Chloramine T can be used effectively, without causing the adverse effects inherent to prolonged use of chlorhexidine. CLINICAL RELEVANCE: Importance of oral hygiene for patients admitted to hospitals with the use of adjuvant substances that do not present adverse effects such as chlorhexidine, which is considered the gold standard, seeking to provide better clinical protocols.

Daily Chlorhexidine Bath for Health Care Associated Infection Prevention (CLEAN-IT): protocol for a multicenter cluster randomized crossover open-label trial.

BACKGROUND: Critically ill patients are at increased risk of health care-associated infections due to various devices (central line-associated bloodstream infection, catheter-associated urinary tract infection, and ventilator-associated pneumonia), which pose a significant threat to this population. Among several strategies, daily bathing with chlorhexidine digluconate, a water-soluble antiseptic, has been studied as an intervention to decrease the incidence of health care-associated infections in the intensive care unit; however, its ability to reduce all health care-associated infections due to various devices is unclear. We designed the Daily Chlorhexidine Bath for Health Care Associated Infection Prevention (CLEAN-IT) trial to assess whether daily chlorhexidine digluconate bathing reduces the incidence of health care-associated infections in critically ill patients compared with soap and water bathing. METHODS: The CLEAN-IT trial is a multicenter, open-label, cluster randomized crossover clinical trial. All adult patients admitted to the participating intensive care units will be included in the trial. Each cluster (intensive care unit) will be randomized to perform either initial chlorhexidine digluconate bathing or soap and water bathing with crossover for a period of 3 to 6 months, depending on the time of each center's entrance to the study, with a 1-month washout period between chlorhexidine digluconate bathing and soap and water bathing transitions. The primary outcome is the incidence of health care-associated infections due to devices. The secondary outcomes are the incidence of each specific health care-associated infection, rates of microbiological cultures positive for multidrug-resistant pathogens, antibiotic use, intensive care unit and hospital length of stay, and intensive care unit and hospital mortality. CONCLUSION: The CLEAN-IT trial will be used to study feasible and affordable interventions that might reduce the health care-associated infection burden in critically ill patients.

Tissue response in a rat model of denture stomatitis treated with tissue conditioner containing antifungal complexed with ß-cyclodextrin.

Introduction. Tissue conditioners modified with antifungals are a potential alternative to denture stomatitis (DS) treatment.Gap Statement. Information on tissue response to this treatment before its clinical application is lacking.Aim. This study aimed to evaluate the tissue response of a tissue conditioner modified with antifungals in a rat model of DS.Methodology. After DS induction for 4 days under antibiotic therapy, Wistar rats had their intraoral devices (IODs) relined with the tissue conditioner Softone without (Soft) or with the MICs against Candida albicans of nystatin (Nys) or chlorhexidine (Chx) complexed or not with ß-cyclodextrin (Nys:ßCD and Chx:ßCD). Three controls were included: healthy rats [negative control (Nc)], rats using a sterile IOD [sterile device (Sd)] and rats with DS that did not receive treatment (DS). After 4 days of treatment, the palatal mucosa under the IODs underwent histological processing for morphohistopathological and histometric analyses, morphology of collagen fibres (birefringence), immunohistochemistry for the expression of cell proliferation (proliferating cell nuclear antigen) and cytokine (IL-1ß).Results. The Nc and Sd groups were similar (P>0.05), displaying epithelial and connective tissues without any discernible changes in the parameters assessed. The DS and Soft groups exhibited pronounced epithelial alterations, cell proliferation and expression of the cytokine IL-1ß. In groups treated with drug incorporation (Nys, Chx, Nys:ßCD and Chx:ßCD), all samples demonstrated a reduction in tissue inflammation or complete tissue recovery, with an epithelium compatible with health. For the immunohistochemical parameters, the Chx, Nys:ßCD and Chx:ßCD groups were comparable with Nc (P>0.05).Conclusion. The proposed treatment could be promising for DS, as it led to the tissue recovery of the palatal mucosa. Nevertheless, much lower concentrations of complexed antifungals were required to achieve a similar or higher degree of tissue response compared with uncomplexed drugs in a modified tissue conditioner formulation.

Outcome of Nonsurgical Root Canal Retreatment of Teeth with Persistent Apical Periodontitis Treated with Foraminal Enlargement and 2% Chlorhexidine Gel: A Retrospective Cohort Study.

INTRODUCTION: Nonsurgical root canal retreatment (NS-RCRT) becomes necessary when primary endodontic procedures fail. This study evaluates the efficacy of NS-RCRT using 2% chlorhexidine gel and foraminal enlargement techniques, aiming to assess whether these approaches enhance periapical healing outcomes and success rates compared to traditional NS-RCRT techniques reported in the literature. METHODS: This retrospective cohort study analyzed 120 teeth diagnosed with persistent apical periodontitis, from 80 patients who underwent NS-RCRT between January 2014 and December 2018 at a specialist's private practice. Data were collected following the Preferred Reporting Items for Observational Studies in Endodontics 2023 guidelines. Periapical healing was evaluated using digital periapical radiographs by three calibrated examiners. The outcome of the treatment was analyzed through descriptive statistics and bivariate analyses, including the Chi-Square and Fisher's Exact tests. Treatment outcomes were deemed successful if they showed complete or incomplete repair and unsuccessful if no repair was observed. RESULTS: The average follow-up period was 30 months. Under loose criteria, 92.50% (n = 111) of the teeth were categorized as successful, and 7.5% (n = 9) as unsuccessful. Bivariate analysis indicated that the radiographic restoration of apical transportation was the only factor that significantly influenced the outcome. CONCLUSIONS: NS-RCRT performed in a single visit using the foraminal enlargement technique and 2% chlorhexidine gel demonstrated high success rates and may be an effective alternative to tooth extraction. This method promoted periapical healing and could significantly improve NS-RCRT protocols. Further prospective studies are recommended to corroborate these findings.

Effects of Thai propolis mixed in mineral trioxide aggregate on matrix metalloproteinase-2 expression and activity in inflamed human dental pulp cells.

OBJECTIVES: This study sought to determine effects of Thai propolis extract mixed in mineral trioxide aggregate (MTA) on matrix metalloproteinase-2 (MMP-2) expression and its activity in inflamed human dental pulp cells (HDPCs). MATERIALS AND METHODS: Interleukin-1ß-primed HDPCs were treated with either the eluate of MTA mixed with distilled water, of MTA mixed with 0.75 mg/ml of the propolis extract, or of Dycal®, 0.75 mg/ml of the propolis extract, or 0.2% (v/v) of chlorhexidine for 24 or 72 h. The viability of HDPCs was determined by the PrestoBlue® cytotoxic assay. HDPCs' lysates were analyzed for MMP-2 mRNA expression by RT-qPCR, while their supernatants were measured for MMP-2 activity by gelatin zymography. RESULTS: At 24 and 72 h, a non-toxic dose of the propolis extract at 0.75 mg/ml by itself or mixed in MTA tended to reduce MMP-2 expression upregulated by MTA, while it further decreased the MMP-2 activity as compared to that of MTA mixed with distilled water. The MMP-2 activity of interleukin-1ß-primed HDPCs treated with the eluate of the propolis extract mixed in MTA was significantly lower than that of interleukin-1ß-primed HDPCs at 24 h (p=0.012). As a control, treatment with chlorhexidine significantly inhibited MMP-2 expression induced by MTA and MMP-2 activity enhanced by interleukin-1ß (p<0.05). Treatment with Dycal® caused a significant increase in HDPC's death, resulting in a significant decrease in MMP-2 expression and activity (p<0.05). CONCLUSIONS: MTA mixed with Thai propolis extract can reduce MMP-2 mRNA expression and activity when compared to MTA mixed with distilled water in inflamed HDPCs.

Performance of herbal mouth rinse in the prevention of oral infections / Desempenho de um enxaguante bucal fitoterápico na prevenção de infecções orais / Desempeño del enjuague bucal herbal en la prevención de infecciones orales

Objectives: To evaluate the performance of an herbal Sanative® solution in the postoperative of tooth extractions. Methods: This randomized, crossover, clinical trial was conducted in 30 patients who presented an indication for simple tooth extractions on opposite sides. After surgery, patients received 150 mL of chlorhexidine digluconate 0.12% and an herbal Sanative® for use in the region for seven days after oral surgery. To evaluate the analgesic effect of both protocols, we used a 10 cm visual analog scale (VAS) and postoperative analgesic consumption. To assess the prevalence of postoperative complications, we examined the presence of bleeding, hyperemia, or necrosis seven days after oral surgery. Results: No difference (Wilcoxon test, p> 0.05) was found between the treatments regarding VAS score in the period of 24 hours or 7 days after surgery or regarding postoperative analgesic consumption (Wilcoxon test, p=0.5536). In the period of 7 days, there was a decrease in the VAS score of both groups. However, only chlorhexidine showed difference (Wilcoxon, p= 0.0178). There was no difference between treatments considering bleeding, hyperemia, and necrosis (Fisher's exact test, p= 0.9656). Conclusion: Sanative® presented equal efficacy to chlorhexidine and demonstrated to be a valuable option for the prevention of postoperative complications..(AU)

Objetivo: Avaliar a performance de uma solução fitoterápica Elixir Sanativo® no pós-operatório de extrações dentárias. Material e método: Trata-se de um ensaio clínico randomizado e cruzado, realizado em 30 voluntários que necessitavam de exodontia simples em lados opostos. Após a cirurgia os pacientes receberam 150 ml de digluconato de clorexidina a 0,12% e uma solução de Elixir Sanativo para usar na região operada durante sete dias. Para avaliar o efeito analgésico de ambos os protocolos, utilizamos una escala analógica visual (EAV) de 10 cm o consumo de analgésicos no pós-operatório. Para avaliar a prevalência de complicações pós-operatórias examinamos a presença de sangramento, hiperemia e necrose após sete dias da cirurgia. Resultados: Não houve diferença estatística significante (Wilcoxon, p> 0.05) entre os tratamentos a respeito da escala EVA no período de 24 horas ou 7 dias depois da cirurgia, nem com relação ao consumo de analgésicos (Wilcoxon, p=0.5536). No período de 7 dias, houve uma diminuição na pontuação da escala EVA em ambos os grupos. No entanto, somente a clorexidina apresentou diferença estatisticamente significativa (Wilcoxon, p= 0.0178). Não houve diferença entre os tratamentos quanto às complicações pós-operatórias (sangramento, hiperemia e necrose) (exato de Fisher, p= 0.9656). Conclusão: O elixir Sanativo® apresentou uma eficácia igual a da clorexidina e demonstrou ser uma valiosa opção para a prevenção de complicações pós-operatórias... (AU)

Objetivo: Evaluar el rendimiento de una solución herbal Sanative® en el postoperatorio de extracciones dentales. Métodos: Este ensayo clínico aleatorizado y cruzado se llevó a cabo en 30 pacientes que presentaban indicación de extracciones dentales simples en lados opuestos. Después de la cirugía, los pacientes recibieron 150 mL de digluconato de clorhexidina al 0.12% y una solución herbal Sanative® para usar en la región durante siete días después de la cirugía oral. Para evaluar el efecto analgésico en ambos protocolos, utilizamos una escala analógica visual (EAV) de 10 cm y el consumo de analgésicos en el postoperatorio. Para evaluar la prevalencia de complicaciones postoperatorias, examinamos la presencia de sangrado, hiperemia o necrosis siete días después de la cirugía oral. Resultados: No se encontraron diferencias (prueba de Wilcoxon, p> 0.05) entre los tratamientos con respecto a la puntuación de la EAV en el período de 24 horas o 7 días después de la cirugía, ni en el consumo de analgésicos en el postoperatorio (prueba de Wilcoxon, p=0.5536). En el período de 7 días, hubo una disminución en la puntuación de la EAV en ambos grupos. Sin embargo, solo la clorhexidina mostró diferencia (Wilcoxon, p= 0.0178). No hubo diferencia entre los tratamientos en cuanto a sangrado, hiperemia y necrosis (prueba exacta de Fisher, p= 0.9656). Conclusión: Sanative® presentó una eficacia igual a la de la clorhexidina y demostró ser una opción valiosa para la prevención de complicaciones postoperatorias... (AU)

Comparison of the anti-plaque and anti-gingivitis efficacy of Chlorhexidine and Malva mouthwashes: Randomized crossover clinical trial.

OBJECTIVES: Although mechanical oral hygiene is widely practiced, it faces several challenges. Mouthwashes, such as chlorhexidine (CHX), are being explored as adjuncts to biofilm control, but their prolonged use has several side effects. Consequently, there is ongoing research into natural alternatives. This randomized crossover clinical study aimed to compare the antiplaque and antigingivitis efficacy of 0.12 % CHX and a 5 % Malva sylvestris. METHODS: Forty-four participants were involved in two phases, each comprising three stages with variations in the mouthwash solution used only. During the study, participants refrained from mechanical plaque removal for seven days. At first day, they received whole-mouth prophylaxis and oral health assessment. After three days, gingival inflammation assessment and prophylaxis in were performed in contralateral quadrants. Participants then used a randomly assigned mouthwash solution for four days. On the 7th day, they completed a questionnaire about their perception and appreciation of the mouthwash. Additionally, gingival inflammation and plaque index were also performed by a calibrated examiner. After a minimum 21-day washout period, participants entered the second phase, repeating the three stages. RESULTS: Results showed no statistically significant differences between the Malva sylvestris and CHX groups regarding inflammation and plaque formation. However, CHX demonstrated a significantly greater mean reduction (7th - 4th day) in gingival inflammation compared to Malva (p = 0.02) (0.01 ± 0.19 and 0.00 ± 0.19, respectively). Additionally, participants using CHX reported a more pleasant taste and considered higher plaque control perception (p < 0.05). CONCLUSIONS: In conclusion, both products exhibited similar antiplaque effects, but CHX outperformed Malva in controlling gingival inflammation. CLINICAL SIGNIFICANCE: Mouthwashes with Malva sylvestris may be a good alternative, in a short-term period, to control biofilm. However, lower antigingivitis efficacy may be expected when compared to chlorhexidine.

Glass ionomer cement particles pre-reacted with chlorhexidine: Physical/chemical properties and antimicrobial activity.

OBJECTIVE: Analyze the effects of the functionalization of pre-functionalized GIC particles with chlorhexidine on the physicochemical properties and antimicrobial activity. MATERIALS AND METHODS: Four groups were prepared: (1) GIC (Bioglass R - Biodinamica) - control group; (2) GIC-CHX 1%: Group containing 1% pre-reacted CHX particles; (3) GIC-CHX 2.5%: Group containing 2.5% pre-reacted CHX particles; (4) GIC-CHX 5%: Group containing 5% pre-reacted CHX particles. Hourglass-shaped specimens (10 mm × 2 mm x 1 mm) were fabricated for mechanical tests including cohesive strength (n = 12), modulus of elasticity (n = 12) and microhardness (n = 10). Discs (10 mm × 2 mm) were prepared for the analysis of Ca+2, PO4- and F- ions release (n = 3), and roughness (n = 12). To evaluate the setting time, a Gilmore needle was used according to ISO 9917-1:2016. Disk-shaped specimens (5 × 1mm) were manufactured and subjected to bacterial activity (n = 9) (Streptococcus mutans ATCC 159). RESULTS: Modulus, roughness, setting time and ions release (Ca+2, PO4-, and F-) there were no statistically significant differences among the groups (p > 0.05). The setting time did not change with the incorporation of CHX. The GIC-CHX 2.5% and GIC-CHX 5% groups exhibited superior antibacterial activity compared to the control group and GIC-CHX 1% (p < 0.001). The GIC-CHX 5% group showed the highest microhardness values (p < 0.041), cohesive strength (p < 0.009) when compared to the control group. CONCLUSION: The pre-reacted CHX in GICs was able to confer antimicrobial activity, improve cohesive strength, microhardness, and did not impair ion release, setting time, and roughness.

Effect of pomegranate solution alone or combined with chlorhexidine against oral multispecies biofilm.

AIM: Natural bioactive products have been tested as alternative antimicrobial agents. This study evaluated the effect of Punica granatum extract (PGE) on oral multispecies biofilms. METHODOLOGY: Lyophilized extracts from pomegranate peel were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography (UPLC). Oral multispecies biofilms from 2 donors were grown on four collagen-coated hydroxyapatite discs. After incubation for 7 days or 3 weeks, the biofilms were exposed to water (control), 2% CHX, 10% PGE, 20% PGE or 30% PGE for 3 min. The proportions of dead bacteria were assessed by the live/dead staining and confocal microscopy. After the analysis, the best PGE concentration (30%) was combined with CHX. The experimental phases were repeated using water, 2% CHX, 30% PGE and 30% PGE + 2% CHX. Five random areas of the biofilm on each disc were scanned, resulting in 20 scanned areas for each group. RESULTS: Regarding the biofilm volume, no differences were found amongst solutions (p = .111). The PGE solution killed bacteria effectively in 1-week, 2-week and 3-week-old-plaque biofilms, ranging from 37 to 55.3%, depending on the PGE concentration. The 30% PGE (a) (p = .0009) had greater antibiofilm effectiveness than 2% CHX (b), which killed bacteria in the 25.2 to 48.7% range. The 10% and 20% PGE had intermediate values (ab), without significant differences from 30% PGE (p = 1.002). Water (c) had the lowest proportion of dead bacteria (p < .00001) in a range of 5 to 6.7% and lower effectiveness in killing bacteria (p < .05). The PGE alone or mixed with 2% CHX had greater anti-biofilm effectiveness than CHX (p < .05). The old plaque biofilms were more resistant than the 7-day-old plaque (p < .05). CONCLUSIONS: The 30% PGE (alone or combined with CHX) exhibited a greater antibiofilm effect on oral multispecies biofilms grown on hydroxyapatite discs than 2% CHX.

Efficiency of the photodynamic therapy on viability of Streptococcus mutans in the oral cavity using chitosan nanoparticles: an in vitro study.

PURPOSE: This study aimed to investigate the efficiency of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm in the oral cavity using the photosensitizer chloroaluminum phthalocyanine encapsulated in chitosan nanoparticles (ClAlPc/Ch) at three preirradiation times. METHODS: Biofilms of Streptococcus mutans strains (ATCC 25,175) were cultivated on bovine tooth blocks and exposed to a 10% sucrose solution three times a day for 1 min over three consecutive days. The samples were randomly distributed into five treatment groups (n = 5): (I) aPDT with ClAlPc/Ch with a preirradiation time of 5 min (F5), (II) aPDT with ClAlPc/Ch with a preirradiation time of 15 min (F15), (III) aPDT with ClAlPc/Ch with a preirradiation time of 30 min (F30), (IV) 0.12% chlorhexidine digluconate (CHX), and (V) 0.9% saline solution (NaCl). After treatment, the S. mutans biofilms formed on each specimen were collected to determine the number of viable bacteria (colony-forming units (CFU)/mL). Data were analyzed for normality using the Shapiro-Wilk test and the analysis of variance (ANOVA) and Tukey HSD tests to analyze the number of viable bacteria (α = 0.05). RESULTS: The one-way ANOVA showed a difference between the groups (p = 0.0003), and the Tukey HSD posttest showed that CHX had the highest microbial reduction of S. mutans, not statistically different from the F5 and F15 groups, whereas the NaCl group had the lowest microbial reduction statistically similar to the F30 group. CONCLUSION: The results demonstrate that aPDT mediated by ClAlPc/Ch when used at preirradiation times of 5-15 min can be an effective approach in controlling cariogenic biofilm of S. mutans, being an alternative to 0.12% CHX.

Low-cost antiseptic-impregnated tracheostomy tube for the prevention of ventilator-associated pneumonia caused by multidrug-resistant bacteria: In vitro and pilot study in humans.

Ventilator-associated pneumonia (VAP) is one of the most common causes of nosocomial infections. The aim of this study was to evaluate the antimicrobial and anti-biofilm activity of an in-house low-cost tracheostomy tube impregnated with chlorhexidine and violet crystal. The impregnated tracheostomy tubes demonstrated antimicrobial activity, including for multidrug-resistant bacteria. Fourteen patients were evaluated. During ventilation, VAP occurred in one patient in the coated group and in three patients in the control group (p=0.28). A reduction of biofilm cells was observed. This study provides preliminary evidence to support that the antiseptic impregnation of a tracheostomy tube provides significant antimicrobial activity.

Formulation and assessment of biological properties of garcinia indica fruit extract mouthrinse as an adjunct to oral hygiene regimen: an in vitro analysis.

The prevalence of gingivitis is substantial within the general population, necessitating rigorous oral hygiene maintenance. OBJECTIVE: This study assessed a Garcinia indica (GI) fruit extract-based mouthrinse, comparing it to a 0.1% turmeric mouthrinse and a 0.2% Chlorhexidine (CHX) mouthrinse. The evaluation encompassed substantivity, staining potential, antimicrobial efficacy and cytocompatibility. METHODOLOGY: The study employed 182 tooth sections. For antimicrobial analysis, 64 extracted human teeth coated with a polymicrobial biofilm were divided into four groups, each receiving an experimental mouthrinse or serving as a control group with distilled water. Microbial reduction was assessed through colony forming units (CFU). Substantivity was evaluated on 54 human tooth sections using a UV spectrophotometer, while staining potential was examined on 64 tooth sections. Cytocompatibility was tested using colorimetric assay to determine non-toxic levels of 0.2% GI fruit extract, 0.1% Turmeric, and 0.2% CHX. RESULTS: Data were analysed with one-way ANOVA (α=0.05). Cell viability was highly significant (p<0.001) in the 0.2% GI group (64.1±0.29) compared to 0.1% Turmeric (40.2±0.34) and 0.2% CHX (10.95±1.40). For antimicrobial activity, both 0.2% GI (20.18±4.81) and 0.2% CHX (28.22±5.41) exhibited no significant difference (P>0.05) at end of 12 hours. However, 0.1% Turmeric showed minimal CFU reduction (P<0.001). Substantivity results at 360 minutes indicated statistically significant higher mean release rate in 0.1%Turmeric (12.47±5.84 ) when compared to 0.2% GI (5.02±3.04) and 0.2% CHX (4.13±2.25) (p<0.001). The overall discoloration changes (∆E) were more prominent in the 0.2% CHX group (18.65±8.3) compared to 0.2% GI (7.61±2.4) and 0.1% Turmeric (7.32±4.9) (P<0.001). CONCLUSION: This study supports 0.2% GI and 0.1% Turmeric mouth rinses as potential natural alternatives to chemical mouth rinses. These findings highlight viability of these natural supplements in oral healthcare.

Analysis of chlorhexidine, antibiotics and bacterial community composition in water environments from Brazil, Cameroon and Madagascar during the COVID-19 pandemic.

The widespread of chlorhexidine and antibiotics in the water bodies, which grew during the global COVID-19 pandemic, can increase the dispersion of antibiotic resistance. We assessed the occurrence of these pharmaceutical compounds as well as SARS-CoV-2 and analysed the bacterial community structure of hospital and urban wastewaters from Brazil, Cameroon, and Madagascar. Water and wastewater samples (n = 59) were collected between January-June 2022. Chlorhexidine, azithromycin, levofloxacin, ceftriaxone, gentamicin and meropenem were screened by Ultra-High-Performance Liquid Chromatography coupled with mass spectrometer. SARS-CoV-2 was detected based on the nucleocapsid gene (in Cameroon and Madagascar), and envelope and spike protein-encoding genes (in Brazil). The total community-DNA was extracted and used for bacterial community analysis based on the 16S rRNA gene. To unravel likely interaction between pharmaceutical compounds and/or SARS-CoV-2 with the water bacterial community, multivariate statistics were performed. Chlorhexidine was found in hospital wastewater effluent from Brazil with a maximum concentration value of 89.28 µg/L. Additionally, antibiotic residues such as azithromycin and levofloxacin were also present at concentrations between 0.32-7.37 µg/L and 0.11-118.91 µg/L, respectively. In Cameroon, azithromycin was the most found antibiotic present at concentrations from 1.14 to 1.21 µg/L. In Madagascar instead, ceftriaxone (0.68-11.53 µg/L) and levofloxacin (0.15-0.30 µg/L) were commonly found. The bacterial phyla statistically significant different (P < 0,05) among participating countries were Proteobacteria, Patescibacteria and Dependentiae which were mainly abundant in waters sampled in Africa and, other phyla such as Firmicutes, Campylobacterota and Fusobacteriota were more abundant in Brazil. The phylum Caldisericota was only found in raw hospital wastewater samples from Madagascar. The canonical correspondence analysis results suggest significant correlation of azithromycin, meropenem and levofloxacin with bacteria families such as Enterococcaceae, Flavobacteriaceae, Deinococcaceae, Thermacetogeniaceae and Desulfomonilaceae, Spirochaetaceae, Methanosaetaceae, Synergistaceae, respectively. Water samples were also positive for SARS-CoV-2 with the lowest number of hospitalized COVID-19 patients in Madagascar (n = 7) and Brazil (n = 30). Our work provides new data about the bacterial community profile and the presence of pharmaceutical compounds in the hospital effluents from Brazil, Cameroon, and Madagascar, whose limited information is available. These compounds can exacerbate the spreading of antibiotic resistance and therefore pose a risk to public health.

Reduction of microorganisms in carious dentin by photodynamic therapy mediated by potassium iodide added to methylene blue and red laser.

OBJECTIVE: To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model. METHODS: A microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO2). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm2), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level. RESULTS: CX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log10 for CX for all microorganisms' groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log10 for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively. CONCLUSION: aPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.

Effectiveness of a tissue conditioner containing antifungals in a rat model of denture stomatitis.

AIM: This study investigated the effectiveness of a drug-modified tissue conditioner in an animal model of denture stomatitis. METHODS AND RESULTS: Wistar rats wore a Candida albicans-contaminated palatal device for 4 days. Next, nystatin (Nys) or chlorhexidine (Chx) were added to a tissue conditioner in their raw or ß-cyclodextrin-complexed (ßCD) forms at their minimum inhibitory concentrations. As controls, one group was not subjected to any procedure (NC), one group used sterile devices, one group had denture stomatitis but was not treated (DS), and another had the devices relined with the tissue conditioner without the addition of any drug (Soft). After 4 days of treatment, treatment effectiveness was assessed visually, histologically, and through CFU count, and myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats from the Soft, Nys, Nys:ßCD, and Chx groups presented a significant decrease in the microbial load compared with the untreated group. Treatment groups showed lower MPO and NAG activity compared to the non-treated group. CONCLUSIONS: The addition of antifungals to a soft tissue conditioner can be a promising approach for denture stomatitis treatment.

Influence of different presentation forms of chlorhexidine on contaminated root canals during agitation.

This in vitro study aimed to verify the influence of chlorhexidine (CHX) (gel and solution) in association with different activation protocols on disinfection of root canals contaminated with Enterococcus faecalis. In total, 120 lower premolar roots were selected, contaminated and divided into 12 groups according to irrigation technique and substance. Samples were collected before and after each irrigation technique and analysed for colony-forming units (CFU). Three dentin discs were obtained for quantification of viable intratubular cells by using confocal laser scanning microscopy (CLSM). CFU results showed that sonic and ultrasonic were more effective than conventional irrigation. Ultrasonic activation was more effective than sonic for CHX gel (p < 0.05). CLSM showed that either activation was better than conventional in all groups and root canal thirds (p < 0.05). It was concluded that ultrasonic/sonic activation was more effective than conventional techniques and CHX enhanced intratubular dentin decontamination across all irrigation methods.