Effect of an Oral Frailty Measures Program on Community-Dwelling Elderly People: A Cluster-Randomized Controlled Trial.

INTRODUCTION: Oral frailty describes a trivial decline in the oral function and is considered to be related to frailty. Thus, effective management of oral frailty could prevent or ameliorate physical frailty and the need for care. However, there is a lack of consensus regarding specific interventions for oral frailty. In this cluster-randomized controlled trial, we investigated the effects of a newly developed oral frailty measures program mentored by dentists and dental hygienists for elderly people in a clinical setting. METHODS: Of 3,296 participants included in a field survey, 219 who regularly visited dental clinics and met at least 3 of the following 6 criteria for oral frailty were considered eligible: <20 natural teeth, decreased chewing ability, decreased articulatory oral-motor skills, decreased tongue pressure, and substantial subjective difficulties in eating and swallowing. After applying the inclusion and exclusion criteria, we studied 51 patients in the intervention group (14 men and 37 women; mean age, 78.6 years) and 32 patients in the control group (7 men and 25 women; mean age, 78.0 years). We implemented a 12-week oral frailty measures program only for the intervention group. The program included preparatory oral exercises, mouth-opening training, tongue pressure training, prosodic training, and masticatory training. Primary outcome measures were the chewing ability score, articulatory oral motor skill for /ta/, tongue pressure, subjective difficulty in eating tough foods, and subjective difficulty in swallowing. We compared baseline characteristics using the Mann-Whitney U and χ2 tests for continuous and categorical variables, respectively. A repeated-measures two-way ANOVA was used to determine the efficacy of independent intervention variables, following the Wilcoxon signed-rank test. The groups (intervention/control) and time (baseline/week 12) were the independent variables. Oral frailty measures were the dependent variables. RESULTS: Baseline characteristics and assessment results were similar between groups. We observed significant improvements in the intervention group in terms of articulatory oral motor skill for /ta/ and tongue pressure (p < 0.001). No improvements were observed in the control group. DISCUSSION/CONCLUSION: Our results suggest that our oral frailty measures program effectively alleviates oral frailty. Future studies are needed to clarify the impact on preventing physical frailty and improving the nutritional status.

Quantification and identification of bacteria in acrylic resin dentures and dento-maxillary obturator-prostheses.

PURPOSE: To quantify and identify bacteria detected in acrylic resin dentures and dento-maxillary obturator-prostheses after long-term use. METHODS: The internal layer of denture bases from 13 daily-use removable acrylic resin dentures was sampled, while the inner fluid samples/no-fluid samples of obturators were collected from 11 in-use acrylic resin dento-maxillary obturator-prostheses. Samples were cultured, and isolated bacteria were counted and identified by molecular biological methods. RESULTS: Bacteria were detected in five (38.5%) acrylic resin dentures and six (54.5%) acrylic resin obturators. Four Lactobacillus species and one Propionibacterium species were isolated from three repaired denture bases, and from two non-repaired dentures, two Actinomyces species and Streptococcus mutans were isolated. On the other hand, 17 bacterial species, belonging to the family and genera of Olsenella, Bacillus, Citrobacter, Enterobacteriaceae, Lactobacillus, Pantoea, Peptoniphilus, Klebsiella and Pseudomonas, were isolated from obturators. Several species of viable bacteria were detected in acrylic resin denture bases and obturators.

Inhibitory effect of Ti-Ag alloy on artificial biofilm formation.

Titanium-silver (Ti-Ag) alloy has been improved for machinability and mechanical properties, but its anti-biofilm properties have not been elucidated yet. Thus, this study aimed to evaluate the effects of Ti-Ag alloy on biofilm formation and bacterial viability in comparison with pure Ti, pure Ag and silver-palladium (Ag-Pd) alloy. Biofilm formation on the metal plates was evaluated by growing Streptococcus mutans and Streptococcus sobrinus in the presence of metal plates. Bactericidal activity was evaluated using a film contact method. There were no significant differences in biofilm formation between pure Ti, pure Ag and Ag-Pd alloy, while biofilm amounts on Ti-20% Ag and Ti-25% Ag alloys were significantly lower (p<0.05). In addition, Ti-Ag alloys and pure Ti were not bactericidal, although pure Ag and Ag-Pd alloy killed bacteria. These results suggest that Ti-20% Ag and Ti-25% Ag alloys are suitable for dental material that suppresses biofilm formation without disturbing healthy oral microflora.

Fluoride released from glass-ionomer cement is responsible to inhibit the acid production of caries-related oral streptococci.

OBJECTIVES: Glass-ionomer cements (GICs) are known to have inhibitory effects on bacterial growth, but the biochemical mechanism of this property has not been fully understood. This study aimed to evaluate inhibitory effects of GIC on the acid production of caries-related oral streptococci, and to identify the components responsible for the inhibition. METHODS: An eluate was prepared by immersing set GIC in phosphate-buffered saline at 37 degrees C for 24h. Fluoride and other elements in the eluate were quantified by fluoride ion electrode and atomic absorption photometry, respectively. Streptococcus mutans NCTC 10449 and Streptococcus sanguinis NCTC 10556 were used to evaluate the pH fall and the rate of acid production after the addition of glucose in the presence or absence of the eluate. Acidic end products from glucose were also assayed by carboxylic acid analyzer. RESULTS: The eluate contained silicon (1.24+/-0.26 mM), fluoride (0.49+/-0.02 mM) and aluminum (0.06+/-0.00 mM), and inhibited the pH fall and the acid production rate of both streptococci at acidic pH, with a concomitant decrease in lactic acid production. These effects were comparable to those of a potassium fluoride solution containing the same concentration of fluoride as the eluate. SIGNIFICANCE: These results indicate that the GIC eluate inhibits the acid production of caries-related oral streptococci at acidic pH and that the effect is due to fluoride derived from the GIC. Thus, adjacent to GIC fillings, bacterial acid production and the subsequent bacterial growth may decrease, establishing a cariostatic environment.