Role of reactive oxygen species (ROS) in the regulation of adipogenic differentiation of human maxillary/mandibular bone marrow-derived mesenchymal stem cells.

BACKGROUND: Maxillary/mandibular bone marrow-derived mesenchymal stem cells (MBMSCs) exhibit a unique property of lower adipogenic potential than other bone marrow-derived MSCs. However, the molecular mechanisms regulating the adipogenesis of MBMSCs remain unclear. This study aimed to explore the roles of mitochondrial function and reactive oxygen species (ROS) in regulating the adipogenesis of MBMSCs. METHODS AND RESULTS: MBMSCs exhibited significantly lower lipid droplet formation than iliac BMSCs (IBMSCs). Moreover, the expression levels of CCAAT/enhancer-binding protein ß (C/EBPß), C/EBPδ, and early B cell factor 1 (Ebf-1), which are early adipogenic transcription factors, and those of peroxisome proliferator-activated receptor-γ (PPARγ) and C/EBPα, which are late adipogenic transcription factors, were downregulated in MBMSCs compared to those in IBMSCs. Adipogenic induction increased the mitochondrial membrane potential and mitochondrial biogenesis in MBMSCs and IBMSCs, with no significant difference between the two cell types; however, intracellular ROS production was significantly enhanced only in IBMSCs. Furthermore, NAD(P)H oxidase 4 (NOX4) expression was significantly lower in MBMSCs than in IBMSCs. Increased ROS production in MBMSCs by NOX4 overexpression or treatment with menadione promoted the expression of early adipogenic transcription factors but did not induce that of late adipogenic transcription factors or lipid droplet accumulation. CONCLUSIONS: These results suggest that ROS may be partially involved in the process of MBMSC adipogenic differentiation from undifferentiated cells to immature adipocytes. This study provides important insights into the tissue-specific properties of MBMSCs.

Factors Associated with Food Form in Long-Term Care Insurance Facilities.

We examined factors related to dietary intake status (food form) of long-term care facility (LTCF) residents to identify factors related to proper food form choice for older individuals requiring nursing care. We surveyed 888 residents from 37 LTCFs in Japan. We evaluated basic information (age, sex, body mass index [BMI]), food form (swallowing-adjusted diet class), Barthel Index (BI), Clinical Dementia Rating (CDR), simply evaluated eating and swallowing functions, the number of present/functional teeth, oral diadochokinesis, repetitive saliva swallowing test (RSST), and modified water swallowing test. To clarify factors associated with food form, participants who had good nutrition by oral intake were categorized into the dysphagic diet (DD) and normal diet (ND) groups. Multi-level analyses were used to detect oral functions associated with food form status. Among objective assessments, BMI (odds ratio [OR] 0.979, 95% confidence interval [CI] - 0.022- to 0.006, p = 0.001), BI (OR 0.993, 95% CI - 0.007 to - 0.004, p < 0.001), CDR 3.0 (OR 1.002, 95% CI 0.002‒0.236, p = 0.046), present teeth (OR 0.993, 95% CI - 0.007 to - 0.001, p = 0.011), functional teeth (OR 0.989, 95% CI - 0.011 to - 0.005, p < 0.001), and RSST (OR 0.960, 95% CI - 0.041 to - 0.007, p = 0.006) were significantly associated with DD vs ND discrimination. Simple evaluations of coughing (OR 1.056, 0.054‒0.198, p = 0.001) and rinsing (OR 1.010, 0.010‒0.174, p = 0.029) could also discriminate food form status. These simple evaluations provide insight into the discrepancies between food form status and eating abilities of LTCF residents. Periodic evaluations by the nursing caregiver may help to prevent aspiration by older individuals with dysphagia.

Pneumonia incidence and oral health management by dental hygienists in long-term care facilities: A 1-year prospective multicentre cohort study.

OBJECTIVE: To investigate the association between oral health management (OHM) by dental hygienists and the occurrence of pneumonia, and determine the effectiveness of OHM in pneumonia prevention. BACKGROUND: In long-term care facilities in Japan, the need for professional OHM is increasing with an increase in the number of severely debilitated residents. MATERIALS AND METHODS: A 1-year prospective multicentre cohort study was conducted using data from 504 residents (63 men; mean age: 87.4 ± 7.8 years) in Japanese long-term care facilities. Basic information, medical history, willingness to engage in oral hygiene behaviour, need for OHM and oral conditions were investigated at baseline. In addition, information on the occurrence of pneumonia was collected using a follow-up survey after one year. A Poisson regression analysis with robust standard errors was conducted, with pneumonia as the dependent variable, and factors associated with OHM and pneumonia occurrence as explanatory variables. RESULTS: Overall, 349 (69.2%) residents required OHM by dental hygienists during that year of follow-up. Of those, 238 (68.2%) were provided with OHM, and 18 (7.5%) developed pneumonia. Among the 111 patients (31.8%) who were not provided with OHM, 21 (18.9%) developed pneumonia. The OHM group had lower pneumonia rates than the non-OHM group (prevalence rate ratio: 0.374; 95% CI: 0.210-0.665). CONCLUSION: Oral health management by dental hygienists was associated with a lower incidence of pneumonia among residents of long-term care facilities, underlining the importance of professional OHM for such individuals. It is recommended that OHM be practised routinely in long-term care facilities.

Effects of Storage Temperature and pH on the Antifungal Effects of Commercial Oral Moisturizers against Candida Albicans and Candida Glabrata.

Background and objectives: Oral moisturizers have been used to treat dry mouth. This study aimed to investigate the effects of storage temperature and pH on the antifungal effects of oral moisturizers against Candida albicans and Candida glabrata. Materials and Methods: Thirty-one oral moisturizers and amphotericin B (AMPH-B) were stored at 25 and 37 °C for 1 week. Subsequently, they were added to cylindrical holes in 50% trypticase soy agar plates inoculated with C. albicans and C. glabrata (107 cells/ml). The antifungal effects were evaluated based on the sizes of the growth-inhibitory zones formed. Two-way analysis of variance was used to determine the effects of storage temperature and pH on the growth-inhibitory zones. Results: Significant differences in the effects of storage temperature and pH of the moisturizers were observed against C. albicans and C. glabrata. The growth-inhibitory zones of samples stored at 37 °C and with neutral pH were significantly larger than those stored at 25 °C and with acidic pH, respectively. The sizes of the zones formed by most of the oral moisturizers were larger than those formed by AMPH-B (concentration, 0.63 µg/ml). Conclusion: The antifungal effects of oral moisturizers against C. albicans and C. glabrata were affected by their storage temperature and pH.

A Retrospective Cohort Study of the Cumulative Survival Rate of Obturator Prostheses for Marsupialization.

PURPOSE: After marsupialization of benign tumors and jawbone cysts, insertion of an obturator prosthesis maintains the surgical opening and improves hygiene. To date, there have been no reports clarifying the relationship between the obturator design and treatment outcomes. The purpose of this study was to examine the survival rate of three types of obturator, and to investigate the factors that expedite the removal of the obturator. MATERIALS AND METHODS: The subject group comprised 100 patients who had an obturator inserted after marsupialization at Kagoshima University Hospital between May 31, 2012 and March 31, 2015; 73 patients with lesions in the mandible were eligible. Three types of mandibular obturator were designed and inserted, considering the teeth missing, the anteroposterior position of the lesion, and the buccolingual direction of marsupialization. The endpoint of this study was defined as the removal of the obturator. The analyzed predictor values for the endpoint were age, gender, remaining teeth, nature of primary disease, anteroposterior location of primary disease, buccolingual direction of marsupialization, type of obturator, and dates of insertion and removal. RESULTS: No significant differences were found in the cumulative survival rate among the three types of obturator. Early obturator removal was more frequent in patients with cysts, anterior lesions, and/or marsupialization from the occlusal direction CONCLUSIONS: Because obturator design had minimal effect on the ability of the appliance to maintain the surgical opening, it is preferable to use the least invasive design. Our findings also suggest that the follow-up examination should account for the type of primary disease, the anteroposterior location of the lesion, and the buccolingual direction of marsupialization.

Impact of Type and Duration of Application of Commercially Available Oral Moisturizers on Their Antifungal Effects.

PURPOSE: To examine the impact of oral moisturizer type and application time on antifungal effects. MATERIALS AND METHODS: Seventeen oral moisturizers (7 liquids, 10 gels) and amphotericin B (AMPH-B) were tested. Antifungal effects were evaluated with newly opened moisturizer samples (0 hour) and with samples incubated for 8 hours to simulate contact during sleep. Candida albicans samples (108 cells/ml) were placed into cylindrical holes in 50% trypticase soy agar plates. Antifungal effects were evaluated based on growth-inhibitory zones after 24 hours. Equal quantities of moisturizers showing growth-inhibitory zones were mixed as additional samples. The effects of moisturizer type and application time on growth-inhibitory zones were evaluated with ANOVA. Growth-inhibitory zone sizes were compared with multiple comparisons. RESULTS: Growth-inhibitory zones were found with two liquids, one gel, moisturizer mixtures, and AMPH-B. Significant differences in antifungal effects were found among different moisturizer types and between the 0- and 8-hour groups. The growth-inhibitory zones of the 8-hour group were significantly smaller than those of the 0-hour group. In both the 0- and 8-hour groups, the growth-inhibitory zones of the liquid-gel mixtures were significantly larger than those of other moisturizer types, and were the same size as those of AMPH-B at two concentrations (1.25 and 2.5 µg/ml). Growth-inhibitory zones of individual moisturizers and liquid-liquid mixtures were the same size as those of lower AMPH-B concentrations (0.16, 0.31, and 0.63 µg/ml). CONCLUSION: Our findings suggest that mixing liquid and gel moisturizers improves their antifungal efficiency.

Impact of Types of Moisturizer and Humidity on the Residual Weight and Viscosity of Liquid and Gel Oral Moisturizers.

PURPOSE: Oral moisturizers need to be selected based on their material properties. The purpose of this study was to investigate the effects of moisturizer type and humidity on the residual weight and viscosity of oral moisturizers. MATERIALS AND METHODS: The weight and viscosity of 17 oral moisturizers (7 liquid and 10 gel) at baseline and after 8 hours were measured using an incubator maintained at 37°C at either 85% or 40% relative humidity (RH). The rate of change in weight (RCW) and the rate of change in viscosity (RCV) were calculated. Data were analyzed with two-way analysis of variance (ANOVA) and Scheffe's test to evaluate the effect of the type of moisturizer (liquid or gel) and humidity (85% or 40% RH) on RCW and RCV. Pearson's correlation coefficient was used to evaluate the relationship between RCW and RCV. RESULTS: Two-way ANOVA results indicated that the type of moisturizer and RH had a significant effect on RCW and RCV (p < 0.05); however, the interaction between them was not significant. The results of multiple comparisons showed that gel moisturizers had a significantly lower RCW and higher RCV than liquid moisturizers (p < 0.05). The RCW and RCV at 40% RH were significantly higher than those at 85% RH (p < 0.05). There was no correlation between RCW and RCV in the liquid moisturizer group, but a significant negative correlation was found in the gel moisturizer group (pp = 0.01). CONCLUSION: Because viscosity of gel moisturizers increases as weight decreases, selecting gel moisturizers with a minimal change in weight and viscosity would be preferable in the case of a long-time application and severe dry mouth.

Dry mouth and denture plaque microflora in complete denture and palatal obturator prosthesis wearers.

OBJECTIVE AND BACKGROUND: The purpose of this study was to investigate the association of dry mouth with denture plaque microflora in patients with palatal obturator prostheses from the viewpoint of infection control. METHODS: Thirty palatal obturator prosthesis wearers were compared with 30 healthy maxillary complete denture wearers. Dry mouth was examined using a moisture-checking device and was diagnosed by the measured moisture levels. Denture plaque was collected by rubbing the mucosal surface of the denture with a swab; collected microorganisms were cultured and identified using culture-dependent methods. The number of colonising microorganisms and prevalence of microorganisms were examined according to the type of prostheses and presence of dry mouth using nonparametric tests and frequency analysis (α = 0.05). RESULTS: The prevalence of Candida spp. and Staphylococcus spp. in palatal obturator prostheses was significantly higher than that in complete dentures. In palatal obturator prostheses, the total number of colonising microorganisms showed no significant differences between the groups with and without dry mouth on each side of the prostheses. However, the prevalence of Candida spp. and Staphylococcus spp. in the group with dry mouth was significantly higher than that in the group without dry mouth. The number of microorganisms and moisture levels of palatal obturator prosthesis wearers showed a significantly negative correlation with Candida spp. and Staphylococcus spp., but a positive correlation with Neisseria spp. CONCLUSION: It was concluded that palatal obturator prosthesis wearers with a dry mouth have greater colonisation by Candida spp. and Staphylococcus spp. than do complete denture wearers.

Fabrication of a movable obturator following maxillary reconstruction with slit-shaped fenestration.

Extensive maxillary resection has generally been reconstructed with free skin flaps. Because drooping of the transferred flap causes instability of the obturator prosthesis, maxillary reconstruction often incorporates a slit-shaped oronasal fenestration. Although obturator prostheses for edentulous patients are stabilized with the help of oronasal slits, those for dentate patients are unstable because of flap mobility, resulting in a harmful lateral force exerted on the abutment teeth, causing dislodging of the denture. This report evaluates the benefits of a movable obturator prosthesis for a 60-year-old dentulous patient with maxillary sinus carcinoma. The patient underwent left-sided total maxillectomy, and the defect was reconstructed with a slit-shaped fenestration using a rectus abdominis flap. A conventional obturator prosthesis was inserted; however, drooping of the flap caused instability of the obturator, resulting in nasal regurgitation and fracture of the clasp. To solve this problem, we designed an obturator prosthesis with a movable connection consisting of a ball attachment (patrix) in the metal base and a socket (matrix) in the obturator, which acted as a stress breaker against the harmful force exerted by the flap. Application of this movable obturator prosthesis was a useful solution for a compromising situation created by the surgical procedure. No clinical disorders were observed at the 3-year follow-up.

Influence of an antidiabetic drug on biomechanical and histological parameters around implants in type 2 diabetic rats.

OBJECTIVES: Type 2 diabetes mellitus (DM) has a deleterious effect on dental implant integration into alveolar bone, thought to arise from impaired osteoblast function and consequent reduced bone turnover. However, whether controlling blood glucose with antidiabetic drugs is sufficient to improve implant integration is unclear. This study was designed to evaluate implant integration using diabetic rats with/without an antidiabetic drug. MATERIALS AND METHODS: Titanium screws were surgically implanted in each tibia of 20 Goto-Kakizaki (GK) rats and 5 nondiabetic control rats. After 3 or 9 weeks, osseointegration was determined by testing the removal torque required to displace the screw and by histological analysis of various parameters of bone formation. RESULTS: Removal torque was significantly higher in the nondiabetic control group than in GK rats, irrespective of whether the GK rats had received voglibose. Histology revealed that single-labeled surface area was still high in the GK rats at 9 weeks but had peaked and diminished in control rats. Bone-implant contact area was reduced in GK rats. CONCLUSIONS: Despite controlling blood glucose, voglibose was unable to reverse the bone metabolic effects of DM.

Comparison of a saliva wetness tester and a moisture-checking device in patients with maxillary obturator prostheses.

OBJECTIVE: Examination of dry mouth in postoperative oral tumour patients should ideally be performed simply and quickly at the chair side. Moisture-checking devices and saliva wetness testers are available for such moisture measurement. Previous studies have reported that moisture-checking devices are useful to examine dry mouth in patients with maxillary obturator prostheses. However, because the measurement principles of saliva wetness testers differ from those of moisture-checking devices, diagnosis by the two devices may result in diagnostic disagreement. The purpose of the present study was to compare the usefulness of a saliva wetness tester with a moisture-checking device for patients with maxillary obturator prostheses. METHODS: Oral moisture was measured with a moisture-checking device and a saliva wetness tester in 30 subjects with maxillary obturator prostheses. These measurements were performed five times at the lingual mucosa, and mean values of each measurement were calculated. The reference value for moisture measurements with the moisture-checking device was 29%, and that with the saliva wetness tester was 3 mm. Subjects were classified as having dry mouth when their moisture measurements were less than the reference values. RESULTS: The diagnostic results of the saliva wetness tester were in agreement with those of the moisture-checking device. The respective moisture measurements showed a significant positive correlation (r=0.88, p<0.01). CONCLUSION: The results of the present study demonstrate that saliva wetness testers are as useful as moisture-checking devices to examine dry mouth in patients with maxillary obturator prostheses.

Survival of microorganisms on complete dentures following ultrasonic cleaning combined with immersion in peroxide-based cleanser solution.

OBJECTIVES: To compare ultrasonic cleaning combined with immersion in a commercially available peroxide-based cleanser solution (Polident(®) ) with other denture cleaning methods, we examined the quantity of micro-organisms that survived on dentures before and after various cleaning methods. SUBJECTS AND METHODS: One hundred complete dentures belonging to 50 nursing home residents (mean age, 84.6 years) were randomly assigned to five groups according to the cleaning method employed: (A) immersion in Polident(®) solution alone, (B) brushing with water, (C) ultrasonic cleaning with water, (D) method (A) followed by method (B) and (E) ultrasonic cleaning combined with immersion in Polident(®) solution. Before and after the dentures had been cleaned, denture biofilm was collected from the mucosal surface of each lateral half of the examined dentures. The collected micro-organisms were cultured, presumptively identified by standard methods and quantified. Comparisons between the five cleaning methods were carried out using the Kruskal-Wallis test and Dunn's multiple comparisons test. RESULTS: The denture cleaning methods involving the use of Polident(®) solution (methods A, D and E) were significantly more effective at denture disinfection than the other methods (p < 0.05); in particular, the quantity of Candida spp. was lowest after method E (median, 0.00; significantly lower than those observed after methods A, B and C; p < 0.05). CONCLUSION: It was concluded that ultrasonic cleaning combined with immersion in a peroxide-based cleanser solution effectively reduces the quantity of micro-organisms surviving on dentures and is a suitable method for elderly individuals who find brushing their dentures difficult.

Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial.

PURPOSE: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. METHODS: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible. RESULTS: Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson's correlation coefficient, P < 0.0001). CONCLUSIONS: Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions.

An in vitro study on the selection of surfactants for removal of cream denture adhesives from dentures and their application to denture cleaners.

Purpose Denture adhesives improve the stability of incompatible dentures; however, complete removal of adhesives after use is difficult. Only a few studies have focused on the removal of denture adhesives. Hence, this study aimed to assess the efficacy of surfactants in removing cream denture adhesives from acrylic resin materials.Methods Solutions of twelve surfactants with various hydrophilic-lipophilic balance (HLB) values were prepared. Two cream denture adhesives, colored for visualization, were spread onto transparent acrylic resin plates. After immersion into surfactant solutions, the effects of the surfactants on residual adhesives were evaluated. We also investigated the effect of denture cleaners (with or without the surfactants) on the removability of adhesives and artificial oily dirt, and their effects on the surface properties of denture materials. The obtained data were analyzed using appropriate statistical methods.Results Five surfactants [BT-5, BL-4.2, BT-7, BT-9, and Triton X-100 (TX)] with HLB values in the 10.5-13.5 range effectively removed adhesives. Addition of BT-9 and TX (HLB=13.5) to denture cleaners improved the adhesives' removal. Furthermore, the addition of TX to the cleaners did not interfere with the removal of artificial oily dirt and did not damage the denture materials' surface.Conclusions Surfactants with HLB values in the 10.5-13.5 range are suitable for removal of cream denture adhesives from acrylic resin materials. In particular, TX (HLB=13.5) efficiently removes adhesives without damaging denture materials or impairing original detergency.

Association between Death or Hospitalization and Observable Variables of Eating and Swallowing Function among Elderly Residents in Long-Term Care Facilities: A Multicenter Prospective Cohort Study.

This 1-year multicenter prospective cohort study aimed to determine the association between observable eating and swallowing function factors and outcomes (death/hospitalization or survival) among elderly persons in long-term care insurance facilities in Japan. Baseline assessments of factors, such as language, drooling, halitosis, hypersalivation, tongue movement, perioral muscle function, coughing, respiration after swallowing, rinsing, and oral residue, among others, were conducted. A score of 0 was considered positive, and a score of 1 or 2 was considered negative. Patient age, sex, body mass index, Barthel index, and Clinical Dementia Rating were recorded. The death/hospitalization or survival rates over 1 year were recorded, and patients were allocated into groups depending on the respective outcome (death/hospitalization group or survival group) and baseline characteristics. A total of 986 residents from 32 facilities were included, with 216 in the death/hospitalization group and 770 in the survival group. Language, salivation, halitosis, perioral muscle, coughing, respiration after swallowing, rinsing, and oral residue were significantly associated with the outcomes (p < 0.05). Therefore, routine performance of these simple assessments by caregivers may allow early detection and treatment to prevent death, pneumonia, aspiration, and malnutrition in elderly persons.

Association between denture use and food form in older adults requiring long-term care: A multicenter cross-sectional study.

PURPOSE: This study aimed to determine whether denture use contributes to maintaining and improving food forms in long-term care facility (LTCFs) residents. METHODS: In 888 residents of 37 LTCFs in Japan, the following were investigated: nutritional intake status, food forms, age, sex, Barthel index (BI), clinical dementia rating (CDR), number of teeth present, number of occlusal supports, swallowing function, and use of dentures. Among all residents, those who were well-nourished and had ≤9 occlusal supports were analyzed. Based on standardized criteria, the food forms consumed by the subjects were divided into two groups: dysphagia and normal diet, which were further classified into four levels. Analysis was performed using a generalized estimation equation with the four levels of food forms as dependent variables and age, sex, BI, CDR, presence of dysphagia, number of teeth present, and use of dentures as independent variables. RESULTS: The final analysis included 622 (70.0%) residents. Of these, 380 (61.1%) used dentures. The analyses revealed that food form was significantly associated with age (adjusted odds ratio [OR], 0.98), BI (OR, 1.04), number of teeth present (OR, 1.03), presence of dysphagia (OR, 0.44), and use of dentures (OR, 2.82). CONCLUSIONS: Denture use was associated with food forms among Japanese LTCF residents. This indicates that the use of dentures is related to the maintenance of food forms, even in the elderly who participate in few activities of daily living, have reduced cognitive function, and require long-term care.

Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers: A multicenter, randomized controlled trial.

PURPOSE: This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial. METHODS: Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type denture adhesive, and control (saline solution). Denture adhesives and saline solution were applied to the dentures for 4 days. The retentive force of the dentures and occlusal force were measured using a force transducer occlusal force meter at baseline and after 4 days of intervention. In addition to between-group comparisons, subgroup analyses of denture retention and occlusal force were performed based on the level of difficulty of the edentulism treatment. The levels were ranked as I (easy), II, III, and IV (difficult). RESULTS: Cream-type denture adhesives significantly improved the retentive force of the dentures (P<0.01) and occlusal force (P<0.05), with no significant differences between baseline and post-intervention forces in the powder-type denture adhesive and control groups. In within-group comparisons, cream-type denture adhesives improved both the retentive and occlusal forces at Level II (P<0.05), and powder-type denture adhesives improved the occlusal force at Level II (P<0.01). CONCLUSIONS: Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment.

Prosthodontic treatment can improve the ingestible food profile in Japanese adult outpatients.

PURPOSE: To investigate the effect of prosthodontic treatment on the ingestible food profile in adult Japanese outpatients, and to identify the related risk factors that can deteriorate the profile. METHODS: The participants were 277 outpatients who visited university-based specialty clinics in Japan for prosthodontic treatment. The demographic data, number of present teeth assessed via intraoral examination, and oral health-related quality of life assessed by the total Oral Health Impact Profile (OHIP-J54) scores of all participants were recorded before treatment. Ingestible food profile score (IFS) was recorded using a validated food intake questionnaire. Eligible participants who answered the questionnaire before and after treatment were categorized into five groups based on the prosthodontic treatments they received (i.e., crowns, bridges, removable partial dentures, removable complete dentures, and removable complete and partial dentures). RESULTS: Multivariate analysis of covariance revealed a statistically significant main effect of prosthodontic intervention (time course: before and after treatment) on mean IFS (P=0.035, F=4.526), even after adjusting for covariates (age, number of present teeth, and treatment modality). Multiple linear regression analysis revealed that the low number of present teeth (r=0.427, P<0.001) and a high OHIP-J54 total score (r=-0.519, P<0.001) of the patients at the baseline were significantly associated with their baseline IFSs, even after adjusting for confounding variables. CONCLUSIONS: The findings of this multicenter follow-up study indicate the importance of prosthodontic rehabilitation in improving patients' ingestible food profiles.

Examination of denture-cleaning methods based on the quantity of microorganisms adhering to a denture.

OBJECTIVES: To investigate effective denture-cleaning methods, we examined the relationships between the quantity of microorganisms adhering to dentures and the use of a denture brush and the frequency of use of a denture cleanser. SUBJECTS AND METHODS: Denture plaque was collected from the mucosal surface of the examined dentures, which were 142 and 80 upper and lower complete dentures, respectively, worn by 96 outpatients (mean age: 71.9 years) of a university hospital and 41 nursing home residents (mean age: 84.8 years). The collected microorganisms were counted in terms of isolated representative colonies that were cultured and identified using standard methods. The use of a denture brush, the frequency of use, and the type and soaking time of denture cleansers as denture-cleaning methods were surveyed. RESULTS: The quantity of microorganisms was significantly lower in dentures of denture brush users than in those of non-users in the outpatients (p < 0.01, Mann-Whitney U test). The quantity of microorganisms was significantly lower in the dentures of outpatients who used a denture cleanser daily or 3-4 times a week than in those who used one once or less per month and in the dentures of nursing home residents who used one daily than in those who used one at other frequencies (p < 0.05, Kruskal-Wallis test, followed by Dunn's Multiple Comparison test). CONCLUSION: Within the limitations of this study, it was concluded that the use of a denture brush and daily use of denture cleanser should be recommended to complete dentures wearers as denture-cleaning methods that effectively reduce the quantity of microorganisms adhering to dentures.

Impact of Surface Changes and Microbial Adhesion on Mucosal Surface Finishing of Resin Denture Bases by Shot Blast Polishing Using Viscoelastic Media.

Surface changes and microbiological effects following shot blast polishing with viscoelastic media of the mucosal surface of resin denture bases were examined. Average surface roughness (Ra) and the depth of surface removal of specimens were measured over time, and the clinical number of microbial adhesions on the mucosal surface of dentures was clinically assessed. The results obtained showed no changes in Ra after 20 s of polishing, Ra of <0.2 µm, and a depth of surface removal < 20 µm. This method of finishing did not affect the fit of the mucosal surface of the dentures. Furthermore, the adhesion of microorganisms to the mucosal surface of dentures was significantly suppressed. Shot blast polishing with viscoelastic media is useful for finishing the mucosal surface of resin denture bases.