Enhancing antifungal and antibacterial properties of denture resins with nystatin-coated silver nanoparticles.

Long-term oral health issues caused by fungi and bacteria are a primary concern for individuals who wear dentures. Denture stomatitis, primarily caused by Candida albicans (C. albicans), is a prevalent condition among denture users. Metal nanoparticles exhibit improved antimicrobial effectiveness and fewer adverse effects. This study aimed to evaluate the antifungal and antibacterial effects of nystatin-coated silver nanoparticles (Nys-coated AgNPs) embedded in acrylic resin as a more biocompatible material for denture resins. AgNPs and Nys-coated AgNPs were synthesized and characterized using UV-Vis, SEM, EDX, and DLS. Specimens of polymethyl methacrylate (PMMA) with three different concentrations of Nys, AgNPs, and Nys-coated AgNPs (0.1%, 1%, 10% w/w) were prepared. The water absorption properties of the disks and drug release were investigated for 14 days and 120 h, respectively. The hydrophilic and hydrophobic properties of the samples and their contact angles were evaluated using the sessile drop technique. The antifungal and antimicrobial activity of the prepared discs was studied against C. albicans and Streptococcus mutans, respectively. Adding Nys-coated AgNPs decreased the contact angle of discs from 67° to 49°. Furthermore, the water absorption rates of the different discs were not significantly different from those of the control groups. Results showed that Nys-coated AgNPs (10% w/w) in PMMA effectively inhibited C. albicans growth better than Nys composites (10% w/w). Additionally, Nys-coated AgNPs composites, as well as AgNPs-containing composites, showed considerable antibacterial activity against S. mutans. Nys-coated AgNPs (10% w/w) had no toxic effect on NIH3T3 cells. In conclusion, Nys-coated AgNPs could be considered a good candidate for incorporation into denture resins to address chronic oral diseases.

Enhanced Antimicrobial Properties of Polymeric Denture Materials Modified with Zein-Coated Inorganic Nanoparticles.

Background: Polymeric denture materials can be susceptible to colonization by oral microorganisms. Zein-coated magnesium oxide nanoparticles (zMgO NPs) demonstrate antimicrobial activity. The aim of this study was to investigate the antimicrobial effect and adherence of different oral microorganisms on hybrid polymeric denture materials incorporated with zMgO NPs. Methods: Five types of polymeric denture materials were used. A total of 480 disc-shaped specimens were divided by material type (n=96/grp), then subdivided by zMgO NPs concentration: control with no nanoparticles and other groups with zMgO NPs concentrations of 0.3%, 0.5% and 1% by weight. Characterization of the polymeric denture materials incorporating zMgO NPs was done, and the antimicrobial activity of all groups was tested against four types of microorganisms: 1) Streptococcus mutans, 2) Staphylococcus aureus, 3) Enterococcus faecalis and 4) Candida albicans. The samples underwent an adherence test and an agar diffusion test. Experiments were done in triplicates. Results: The characterization of the hybrid samples revealed variation in the molecular composition, as well as a uniform distribution of the zMgO NPs in the polymeric denture materials. All hybrid polymeric denture materials groups induced a statistically significant antimicrobial activity, while the control groups showed the least antimicrobial activity. The agar diffusion test revealed no release of the zMgO NPs from the hybrid samples, indicating the NPs did not seep out of the matrix. Conclusion: The zMgO NPs were effective in reducing the adherence of the tested microorganisms and enhancing the antimicrobial activity of the polymeric denture materials. This antimicrobial effect with the polymeric dentures could aid in resisting microbial issues such as denture stomatitis.

[A preliminary study on the construction and application of the common prosperity model for the oral health of the elderly in economic acceleration zone].

Objective: To evaluate preliminary application effects of a provincial-county-township-village four-level network framework which aims at promoting oral health of the elderly, and to conduct preliminary evaluations of the application of this model in the prevention and treatment of oral diseases among the elderly in economically accelerated areas. Methods: Based on the population survey in June 2022, the study focuses on the elderly (≥85 years old) veterans who fought in the Korean War and currently resided in Wuyi County, an old revolutionary base area in Zhejiang Province with accelerated economic development. A four-level network medical service model matrix was constructed, spanning from the provincial level to the county, township, and village. Digital oral health records were established, and in-home dental treatment was provided for elderly individuals who met the inclusion and exclusion criteria. Pre-treatment and 3-months follow-up visits were conducted, and the impact of oral health was recorded using a scale, along with a survey of denture satisfaction. Results: A total of 54 elderly individuals received the geriatric oral healthcare services. After a 3-months follow-up, the mean total score of the oral health impact profile-14 questionnaires was (3.27±3.00), which was significantly lower than the score (32.82±7.15) in pre-treatment ones (Z=-2.94, P=0.003). Scores in dimensions such as physical pain, functional limitations, psychological discomfort, psychological disorders, and physical disorders were all significantly lower than the pre-treatment scores (P<0.05). The visual analogue score for denture satisfaction was 48.64±1.21, indicating a satisfaction rate of 100% (11/11). Conclusions: These findings confirm the favorable preliminary application effects of the four-level network framework in improving the prevention and treatment of oral diseases among the elderly in economically accelerated areas.

Antibacterial effect of Softsoap used to disinfect dentures.

PURPOSE: To evaluate the in vitro antibacterial effect of Softsoap and Efferdent used as solutions to disinfect Lucitone 199 poly(methyl methacrylate) (PMMA) resin used for dentures. METHODS: S. mutans and plaque bacteria were grown for 24 hours, and suspended to a concentration of 1x106 cells/ml. Bacterial suspensions (0.2 mL) were added to the decontaminated PMMA discs placed in a 48-well culture plate and incubated for 3 days at 37°C. The discs were rinsed to remove the unbound bacterial cells and then incubated for 60 minutes with 5% and 1% dilutions (triplicates) of each of the detergent solutions (0.3 ml). Discs were rinsed and then MTT reagent (0.2 ml) was added and incubated for 2 hours, then overnight with a solubilizing agent. An aliquot from each well (0.1 ml) was transferred to a 96-well flat bottom plate and absorbance was measured to OD @ 595 nm (MTT) of four samples for each data point. Normalized data was compared and statistically analyzed using a three-way ANOVA with Student-Newman-Keuls on Rank data with P< 0.05 for significance. Additionally, data were double-checked with the Holm-Sidak test. RESULTS: There was no statistically significant difference between testing media for C. albicans and mixed plaque (P= 0.078) or testing duration in time at 24 hours and 21 days (P= 0.07). Statistically significant differences were found between all treatment solutions group combinations (P< 0.001) except for 30% Softsoap versus Efferdent (P= 0.056). CLINICAL SIGNIFICANCE: There was no statistically significant difference between testing media for C. albicans and mixed plaque (P= 0.078) or testing duration at 24 hours and 21 days (P= 0.07). Statistically significant differences were noted between all treatment solutions group combinations (P< 0.001), However, there was no difference between 30% Softsoap and Efferdent (P= 0.056).

[Evaluation of efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction].

PURPOSE: To explore the efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction(ADDwoR). METHODS: Sixty patients of ADDwoR and dentition defect or severely worn teeth who visited the Department of Orthodontics and Prosthodontics of Hengshui People's Hospital from January 2019 to December 2020 were selected and randomly divided into denture occlusal plate group (group A) and denture occlusal plate + comprehensive physical therapy group (group B) according to the treatment methods. Maximum mouth opening (MMO) and visual analog pain score(VAS) among all patients were recorded before treatment and every three weeks during three months of treatment. Cone-beam CT(CBCT) was taken before and 3 months after treatment. The changes in clinical efficacy indicators before and after treatment and CBCT data between the two groups were analyzed. Statistical analysis was performed with SPSS 26.0 software package. RESULTS: The differences of VAS of group A and B were statistically significant from before treatment to three weeks after treatment(P＜0.05), and group B decreases more. From 3 weeks after treatment, there was a significant difference of group B for MMO and VAS before treatment (P＜0.05). From 9 weeks after treatment, there was a significant difference of group A for MMO before treatment (P＜0.05), but there was no significant difference in MMO and VAS between group A and B(P＞0.05). CBCT showed narrowed anterior joint space, widened posterior joint space, enlarged superior joint space, decreased horizontal angle of the condyle and increased slope of joint nodules (P＜0.05). The difference between joint depth, anteroposterior diameter of the condyle, internal and external diameter was not significant (P＞0.05). There was significant differences in anterior, superior, and posterior joint space, condylar level angle, and slope of joint nodules of group B compared with group A(P＜0.05). CONCLUSIONS: Denture occlusal plate can effectively improve symptoms of ADDwoR, and denture occlusal plate combined with comprehensive physical therapy can quickly improve mouth opening and reduce pain in the joint area.

Causal effects of denture wearing on epigenetic age acceleration and the mediating pathways: a mendelian randomization study.

BACKGROUND: The epigenetic-age acceleration (EAA) represents the difference between chronological age and epigenetic age, reflecting accelerated biological aging. Observational studies suggested that oral disorders may impact DNA methylation patterns and aging, but their causal relationship remains largely unexplored. This study aimed to investigate potential causal associations between dental traits and EAA, as well as to identify possible mediators. METHODS: Using summary statistics of genome-wide association studies of predominantly European ancestry, we conducted univariable and multivariable Mendelian randomization (MR) to estimate the overall and independent effects of ten dental traits (dentures, bleeding gums, painful gums, loose teeth, toothache, ulcers, periodontitis, number of teeth, and two measures of caries) on four EAA subtypes (GrimAge acceleration [GrimAA], PhenoAge acceleration [PhenoAA], HannumAge acceleration [HannumAA] and intrinsic EAA [IEAA]), and used two-step Mendelian randomization to evaluate twelve potential mediators of the associations. Comprehensive sensitivity analyses were used to verity the robustness, heterogeneity, and pleiotropy. RESULTS: Univariable inverse variance weighted MR analyses revealed a causal effect of dentures on greater GrimAA (ß: 2.47, 95% CI: 0.93-4.01, p = 0.002), PhenoAA (ß: 3.00, 95% CI: 1.15-4.85, p = 0.001), and HannumAA (ß: 1.96, 95% CI: 0.58-3.33, p = 0.005). In multivariable MR, the associations remained significant after adjusting for periodontitis, caries, number of teeth and bleeding gums. Three out of 12 aging risk factors were identified as mediators of the association between dentures and EAA, including body mass index, body fat percentage, and waist circumference. No evidence for reverse causality and pleiotropy were detected (p > 0.05). CONCLUSIONS: Our findings supported the causal effects of genetic liability for denture wearing on epigenetic aging, with partial mediation by obesity. More attention should be paid to the obesity-monitoring and management for slowing EAA among denture wearers.

Knowledge, attitudes, and practice related to tooth loss and dentures among patients with dental arch deficiencies.

BACKGROUND: Tooth loss is a common problem that affects many people worldwide. Exploring knowledge, attitude, and practice (KAP) among patients can identify barriers and challenges in following recommended practices, providing valuable insights for dental healthcare providers, policymakers, and researchers. This study aimed to explore the KAP of patients with dental arch deficiencies regarding tooth loss and dentures. METHODS: This web-based, cross-sectional study was conducted among patients with dental arch deficiencies using a self-designed questionnaire. RESULT: 3166 valid questionnaires were included. Participants' mean KAP scores were 6.84 ± 2.27 (possible range: 0 ~ 12), 39.4 ± 3.72 (possible range: 9 ~ 45), and 27.7 ± 4.36 (possible range: 8 ~ 40), respectively. Multivariable logistic regression analysis showed that knowledge (OR = 1.383), employed (OR = 1.805), family history (OR = 2.158), and treatment (OR = 1.683) were independently associated with attitude. Moreover, knowledge (OR = 1.239), attitude (OR = 1.250), female (OR = 0.619), age (OR = 0.967), college/bachelor (OR = 0.373), and master and above degree (OR = 0.418), employed (OR = 0.554) or student (OR = 0.434), with 10,001-20,000 Yuan household income per month (OR = 0.492), have been married (OR = 0.609), smoking (OR = 0.595), drinking (OR = 0.397), disease duration (OR = 0.972), with family history (OR = 1.676), and with treatment (OR = 3.492) were independently associated with practice (all P < 0.05). CONCLUSION: Patients with dental arch deficiencies have insufficient knowledge, positive attitudes, and moderate practice toward tooth loss and dentures, which might be affected by multiple demographic factors.

Self-Reported Oral Diseases and Their Association with the Frailty index among Older Japanese People: Four-Year Follow-Up.

BACKGROUND: Oral health is a relevant component for overall health. Oral disease onset at an early age and may harm several health dimensions, especially among older people, and has been associated with frailty. OBJECTIVE: To evaluate associations between the Frailty Index (FI) and self-reported oral diseases among older, community-dwelling Japanese people. DESIGN: Cross-sectional and prospective analyses were performed. SETTING AND PARTICIPANTS: We analyzed data from 2,529 participants at the baseline and four-year follow-up of the Nihon University Japanese Longitudinal Study of Aging, which had a four-year follow-up. MEASUREMENTS: We used the self-reported number of teeth, self-reported satisfaction with dentures, and self-reported ability to chew hard food as independent variables. We computed an FI that included 40 deficits as the dependent variable. The FI score ranged from 0 to 1, with a higher score associated with adverse health outcomes and mortality. Considering a gamma distribution and controlling for age, gender, marital status, education, working status, and residence area, we fitted generalized linear models. RESULTS: We found that dissatisfied denture users had a 2.1% (95% CI 1.006-3.279) higher frailty score than non-denture users at the baseline and a 2.1% (95% CI 0.629-3.690) higher frailty score than non-denture users at the four-year follow-up. In the cross-sectional analysis, with each additional reported tooth at the baseline, the FI score was lower by 1.5% (95% CI -2.878 to -0.208) at the four-year follow-up. In both the cross-sectional and the prospective analyses, the FI scores increased as the ability to chew hard food decreased. CONCLUSIONS: Self-reported oral diseases are associated with the FI score cross-sectionally and prospectively. Identifying factors prospectively associated with frailty may improve strategies for the next generation of older people. Considering oral diseases may help clinicians personalize treatment plans for older people.

Impact of Denture Use on Oral Health-Related Quality of Life in Yemeni Patients: A Cross-Sectional Analysis.

BACKGROUND We used the 14-item Oral Health Impact Profile-14 (OHIP-14) questionnaire to evaluate the association between sociodemographic variables and oral health-related quality of life in 241 wearers of removable partial or complete dentures attending a single center in Yemen. MATERIAL AND METHODS A total of 241 partial dentures (PD) and complete dentures (CD) wearers were enrolled from the Department of Prosthodontics at the Faculty of Dentistry, Sana'a University, and the University of Science and Technology. Data were collected before the commencement of denture wearing and after 3-6 months of denture use. The questionnaire consisted of sociodemographic information and denture type, and another for the OHIP to assess oral health-related quality of life (OHRQoL), oral health impact profile scale comprises 7 subscales, each evaluating different aspects of oral health and functionality. Descriptive statistics were calculated for participants. Independent t tests were performed to compare different patient groups, focusing on PD and CD wearers. Paired-sample t tests were used to examine changes within patient groups before and after removable denture use. RESULTS Among all participants, 67.6% were male, wearers of CDs were 74.6% male, PDs were 58.3%, and was consistent for CD (71.0%) and PD (72.8%) wearers. The wearing prostheses significantly impacted the OHRQoL of patients using both PDs and CDs (P<0.01). Among CD wearers, 4 of these subscales (3-6) were statistically significant, but the handicaps subscale showed evident reductions in physical pain after treatment among PD wearers. CONCLUSIONS Wearing dentures positively affects the OHRQoL of patients, influencing various aspects of their health, including functional, physical, psychological, and social well-being.

Efficacy of ultrasonic home-care denture cleaning versus conventional denture cleaning: A randomised crossover clinical trial.

OBJECTIVE: To compare the efficacy of test (ultrasonic cleaner combined with immersion in denture cleanser solution) and control (immersion in denture cleanser solution followed by conventional brushing) denture cleaning interventions in enhancing denture cleanliness, reducing denture stomatitis, and improving patient satisfaction. METHODS: A prospective, single-blind, block-randomised, two-period crossover, superiority-controlled clinical trial was conducted of a 3-month intervention. The study design included a pre-intervention period (2 weeks), intervention period one (3 months), washout period (2 weeks), and intervention period two (3 months). A total of 56 community-dwelling elders were block-randomized into either sequence Test/Control or sequence Control/Test. The intervention, period, and carryover effects for the changes in the cleanliness of extensive partial and complete acrylic dentures, denture stomatitis, and changes in patient satisfaction were estimated using Generalized Estimating Equations models. RESULTS: Percentage plaque area coverage, patient satisfaction, and denture stomatitis were significantly improved for both intervention and control arms after 3 months (P < 0.05). The intervention arm was found to significantly improve denture cleanliness (P < 0.001) and patient satisfaction (P = 0.002) more than the control arm. Denture-wearing habits and denture age were also significantly associated with the changes in denture plaque coverage (P < 0.05). However, the effect of the test intervention on denture stomatitis was not significantly different compared to the control arm (P = 0.284). CONCLUSION: This study revealed that the test intervention group was significantly more effective than the control group in improving denture cleanliness and patient satisfaction among community-dwelling elders. This test intervention is recommended for maintaining optimum denture hygiene among older adults. CLINICAL SIGNIFICANCE: Removable dentures can harbor opportunistic pathogens, emphasizing the need for effective denture hygiene intervention using ultrasonic cleaner combined with immersion in denture cleanser solution to eliminate denture biofilm in community-dwelling elders.

Effect of silver vanadate on the antibiofilm, adhesion and biocompatibility properties of denture adhesive.

Aim: To evaluate the biological and mechanical properties of an adhesive with nanostructured silver vanadate (AgVO3). Materials & methods: Specimens in poly(methyl methacrylate) (PMMA) were treated with Ultra Corega Cream (UCCA) denture adhesive with or without AgVO3. Biofilms of Candida albicans, Candida glabrata and Streptococcus mutans were grown and the viable cells counted. Fluorescence microscopy was used. The viability of the VERO cell and adhesive strength were evaluated. Results: All concentrations of AgVO3 reduced the biofilm formation and showed no cytotoxic effect. At 5 min and 24 h, UCCA with 5 and 10% AgVO3 showed better performance, respectively. Conclusion: AgVO3 promoted the antibiofilm activity of the adhesive, with a positive effect on the adhesive strength, and was biocompatible.

What is this summary about? Some people wear false teeth called dentures. They use a special glue to keep these false teeth in their mouths. It is important to clean dentures well and remove the glue every day. If the dentures get dirty, they can cause infections of the gums. Doctors and dentists can help, but sometimes medicines do not work well. This study checked to see whether adding a medicine that can kill bacteria into the glue could stop gum swelling and other illnesses, or make them better.What were the results? The glue containing the medicine killed microbes like fungi and bacteria. It also stuck things together well and was safe to use.What do the results mean? Using this special glue could help people with dentures to avoid illness.

Functional teeth and cognitive function among the Chinese elderly: The chain mediating effect of depressive symptoms and social participation.

The objective of this study was to investigate the chain mediating effects of depressive symptoms and social participation between functional teeth and cognitive function based on the biopsychosocial model. Data from the 2018 China Health and Retirement Longitudinal Study were analyzed. The findings revealed a favorable connection between the lack of edentulism and cognitive function, persisting even when accounting for the mediating factors of denture usage, depressive symptoms, and social participation. Furthermore, the study identified six indirect pathways in this relationship. The present study has substantiated the correlation between edentulism and cognitive function, thereby proposing that interventions aimed at denture usage, depressive symptoms, and social participation could potentially serve as preventive measures against cognitive decline in elderly individuals afflicted with edentulism. This underscores the significance of addressing these factors to alleviate cognitive decline.

Impact of Patient Education Formats on Treatment Adherence and Denture Hygiene in Edentulous Patients: A Comparative Study.

BACKGROUND Effective communication and patient education are important in geriatric dental care. Memory decline complicates patient adherence. This study aimed to compare verbal, audio, and video patient education material (PEM) and adherence to dental prosthetic management in edentulous patients. MATERIAL AND METHODS 90 completely/partially edentulous patients (aged 40 to 70 years), were divided (simple random) into three groups (Gp) of 30 each . A total of 68 instructions were organized into 9 learning categories. For GpVi, a 20 minute video was shot using a Sony camera (PD170), with two actors depicting related PEM information. Patients were recalled after 1 day and 7days, to recall the PEM instructions. A Denture plaque Index (DPI) determined the efficiency of the instructions at both time intervals. Frequencies, means and standard deviations were derived for each group and then compared using Chi square, paired and unpaired t test and a Neuman-Keul post hoc pairwise test. All significant differences were kept at probability t value of ≤0.05. RESULTS PEM instructions related to patient individuality, proper tongue position and miscellaneous showed poor patient recall. At 1 day interval, audio was found to have better recall than video and verbal in 5 PEM instruction categories. At 7 day interval, video showed better recall than other two groups (P≤0.05). Despite improvements in patients recall, DPI revealed better denture hygiene maintenance in patients receiving instructions through video format (P≤0.05). CONCLUSIONS For all categories, no single media was considered to be sufficient, audio produced early better recall while video influenced long term recall and better denture hygiene maintenance.

Association between Oral Health and Depressive Symptoms in Chinese Older Adults: The Mediating Role of Dietary Diversity.

Diet is a modifiable factor in healthy population aging. Additionally, oral health and diet are important factors affecting depressive symptoms. To assess the mediating role of dietary diversity (DD) in oral health and depressive symptoms in older adults, we selected 8442 participants aged ≥ 65 years from the 2018 Chinese Longitudinal Health Longevity Survey (CLHLS) for a cross-sectional study. Depressive symptoms were determined based on scores on the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). Dietary diversity scores (DDS) were established based on the frequency of intake of food groups. Oral health was measured by denture use and toothbrushing frequency. Stepwise multiple linear regression and PROCESS macros were used for mediated effects analysis and testing. The sample had a positive detection rate of 44.1% for depressive symptoms, 40.8% for denture use, and 41.9% for once-a-day toothbrushing. Denture use (ρ = -0.077, p < 0.01) and toothbrushing frequency (ρ = -0.115, p < 0.01) were negative predictors of depressive symptoms in older adults. DD significantly mediated the association between denture use (indirect effect -0.047; 95%CI: -0.068-0.028; p < 0.001), toothbrushing frequency (indirect effect -0.041; 95%CI: -0.054-0.030; p < 0.001), and depressive symptoms. Denture use and toothbrushing frequency not only directly reduce the risk of depressive symptoms in older adults, but also indirectly affect depressive symptoms through DD.

The association between objective and subjective oral health conditions and the presence of anorexia of aging among Japanese older Adults1.

Anorexia of aging is a risk factor for malnutrition among older adults. This study aimed to evaluate the association between objective and subjective oral health and anorexia among independent older adults. This cross-sectional study targeted independent older adults aged ≥65 years who participated in the Japan Gerontological Evaluation Study conducted in 2022. The outcome variable was the presence of anorexia, as assessed by the Simplified Nutritional Appetite Questionnaire. Exposure variables were dental status (≥20 teeth, 10-19 teeth with/without dentures, and 0-9 teeth with/without dentures) as objective oral health and oral health-related quality of life measured by five items of the short version of the Oral Impacts on Daily Performances (OIDP) (eating, speaking, smiling, emotional stability, and enjoying with others) as subjective oral health. We fitted the Poisson regression model, including possible confounders, and estimated prevalence ratios (PRs) and 95% confidence intervals. Among 19,787 participants (mean age: 74.6 years [1SD = 6.2], male: 48.5%), 9.0% were classified as having anorexia. After adjusting possible confounders, those with ≤19 teeth had a higher proportion of experiencing anorexia compared to those with ≥20 teeth; however, the association was less pronounced among those with dentures (0-9 teeth with dentures: PR = 1.48 [1.31-1.68], and 0-9 teeth without dentures: PR = 2.08 [1.65-2.63]). Even after adjusting for dental status, each item of OIDP was significantly associated with the presence of anorexia (all p < 0.05). The results showed that both objective and subjective poor oral health were significantly associated with a higher probability of developing anorexia of aging. Therefore, improving both objective and subjective oral health through appropriate dental care could contribute to maintaining appetite in later life.

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

BACKGROUND: Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. OBJECTIVES: To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. METHODOLOGY: The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). RESULTS: All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). CONCLUSIONS: A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.

Effect of various staining beverages on the color stability of CAD/CAM PMMA denture teeth: An in vitro study.

OBJECTIVE: This study aimed to compare the color change of computer-aided design (CAD)/computer-aided manufacturing (CAM) polymethyl methacrylate (PMMA) denture teeth and conventional acrylic teeth after immersion in three staining beverages (coffee, red tea, and cola) for a day, 7 days, and 30 days. MATERIALS AND METHODS: Group 1: Conventional acrylic teeth (n = 32). Group 2: Milled CAD/CAM teeth out of PMMA disc (n = 32). The specimens of each material were further divided into four subgroups: (1) Control group, distilled water (n = 16). (2) Red tea solution (n = 16). (3) Coffee solution (n = 16). (4) Cola (n = 16). The color change ( ∆ E $\unicode{x02206}E$ ) was assessed using a spectrophotometer at four time points: at the baseline (t0 ), on the 1st day (t1 ), on the 7th day (t2 ), and the 30th day (t3 ) of immersion. Kolmogorov-Smirnov test was applied, followed by performing independent samples t test, one-way analysis of variance and post-hoc Tukey tests to compare the color change values at different time points. RESULTS: The mean score of NBS values of the coffee solution indicates perceivable color change at the end of the 30th day in the conventional acrylic teeth group. It was 0.843 ± 0.395 at t1 , then increased to 1.017 ± 0.477 at t2 and to 2.259 ± 1.059 at t3 . There is a statistically significant difference (p < 0.05) in color change values between both tooth types at the end of the 30th day of immersion in red tea solution and a statistically significant difference at the end of the 7th day (p < 0.05) and the 30th day (p < 0.05) of immersion in coffee solution. CONCLUSIONS: CAD/CAM PMMA teeth are more color stable than conventional acrylic teeth after 30 days of immersion in coffee and red tea solution.

Mechanophysical and Anti-Adhesive Properties of a Nanoclay-Containing PMMA Denture Resin.

Poly(methyl methacrylate) (PMMA) is commonly used for dental dentures, but it has the drawback of promoting oral health risks due to oral bacterial adhesion. Recently, various nanoparticles have been incorporated into PMMA to tackle these issues. This study aims to investigate the mechanophysical and antimicrobial adhesive properties of a denture resin by incorporating of nanoclay into PMMA. Specimens were prepared by adding 0, 1, 2, and 4 wt % surface-modified nanoclay (Sigma) to self-polymerizing PMMA denture resin. These specimens were then evaluated using FTIR, TGA/DTG, and FE-SEM with EDS. Various mechanical and surface physical properties, including nanoindentation, were measured and compared with those of pure PMMA. Antiadhesion experiments were conducted by applying a Candida albicans (ATCC 11006) suspension to the surface of the specimens. The antiadhesion activity of C. albicans was confirmed through a yeast-wall component (mannan) and mRNA-seq analysis. The bulk mechanical properties of nanoclay-PMMA composites were decreased compared to those of pure PMMA, while the flexural strength and modulus met the ISO 20795-1 requirement. However, there were no significant differences in the nanoindentation hardness and elastic modulus. The surface energy revealed a significant decrease at 4 wt % nanoclay-PMMA. The antiadhesion effect of Candida albicans was evident along with nanoclay content in the nanocomposites and confirmed by the reduced attachment of mannan on nanoclay-PMMA composites. mRNA-seq analysis supported overall transcriptome changes in altering attachment and metabolism behaviors on the surface. The nanoclay-PMMA materials showed a lower surface energy as the content increased, leading to an antiadhesion effect against Candida albicans. These findings indicate that incorporating nanoclay into PMMA surfaces could be a valuable strategy for preventing the fungal biofilm formation of denture base materials.

Development of lightweight and high-strength hollow titanium-plated denture material using three-dimensional printing.

Owing to its desirable ability to fabricate complex shapes, three-dimensional printing is preferred over casting for manufacturing dentures. Furthermore, titanium is widely used in dental implants and dentures because of its high corrosion resistance, biocompatibility, strength, and low density. In this study, we aimed to develop a new metal denture material from three-dimensional-printed (3DP) to achieve lighter weight and greater strength than those of PMMA dentures. Hollow (3DP-H) structure and solid (3DP-S) structure titanium plate specimens of 0.5, 1.0, and 3.0 mm in thickness were used. Casted Ti, casted Co-Cr, and PMMA plates were fabricated for comparison. Elastic modulus, density, thermal conductivity, hardness, and proof stress of the specimens were measured and plotted on a radar chart to enable multifaceted evaluation. The results indicated that the density of the 3DP-H plates reduced by 28-36% compared with those of 3DP-S and cast Ti plates. The weight of the metal-denture-equivalent section of the 0.5-mm-thick 3DP-H titanium-plated denture reduced to two-thirds that of the 2.0-mm-thick PMMA denture. The proof stress of the 0.5-mm-thick 3DP-H plate increased to about 3 times that of the 2.0-mm-thick PMMA plate. The total value of the 0.5-mm-thick 3DP-H titanium plates was higher than it of the 1.0-mm-thick PMMA plates. This study suggests that it is possible to produce 3DP-H titanium plate dentures exhibiting not only extremely lightweight compared to conventional PMMA dentures but also sufficient strength.