ABSTRACT
This study compared the effectiveness of self-propelling diatom microbubblers to clean dental appliances with commercial denture cleaning agents according to the Ministry of Food and Drug Safety’s guidelines. The microbubbler is made by doping diatoms with MnO2 nanosheets that can decompose hydrogen peroxide to generate oxygen bubbles. Artificial saliva is prepared in accordance with the criteria presented by the American Dental Association, dispensed, and dried in 96 well plates. Experimental groups include 10-15% NaOCl (positive control), distilled water (negative control), diatom microbubbler A (Aulacoseira, MnO2-polydopamine (PDA)-A), diatom microbubbler M (Melosira nummuloids, MnO2-sugar (S)-M), Polident (GlaxoSmithKline, Dungarvan, Ireland), Dentfix-forte (Helago-Phama GmbH&Co, Parchim, Germany). After washing, absorbance (OD 600) was measured. If the absorbance was 70% or higher, the condition was determined to have “cleaning power potency,”Statistical significance was evaluated by one-way ANOVA and Bonferroni correction to compare cleaning effects among groups (p<0.05).The average cleaning rates were 93.8±1.0% in NaOCl (positive control) and 79.1±1.5% in distilled water (negative control).With the diatom microbubbler A, the average cleaning rate was 79.8±4.5% in the 3% H 2O 2 2 mg/mL, 64.7±5.5% in 6% H 2O 2 2 mg/mL, and 81.9±7.9% in 6% H 2O 2 4 mg/mL. The diatom microbubbler M group showed average cleaning rates of 88.5±3.6% in 3% H2O2 2 mg/mL, 75.8±4.0% in 6% H2O2 2 mg/mL, and 84.5±4.5% in 6% H2O2 4 mg/mL. Finally, conventional denture cleaning agents showed average cleaning rates of 88.2±1.2% in Polident and 83.3±3.0% in Dentfix-forte. The positive control group had significant differences from all experimental groups, but the negative control group showed significant differences only in A2 and A3, M1 and M2, M3, Polident, and Dentfix-forte (F=190.141, p<0.001). Among all groups except the positive control group, MnO2 -S-M mixed with 3% H2O2 2 mg/mL showed the highest cleaning rate. As the results of this study show, diatom complexes exhibit cleaning effects compatible with conventional denture cleaning agents. Further studies need to be conducted to narrow down the specific optimal conditions of diatom microbubblers and maximize the cleaning effect.
ABSTRACT
BACKGROUND: Falls in the elderly can lead to disability, hospitalizations, and premature death. Even if the fall does not cause significant injury, it may lead to fear of falling, loss of self confidence and restriction of ambulation. Thus, we conducted this study to examine the risk factors of falls in the elderly. METHODS: The study population consisted of 70 persons, older than 65 years. Subjocts were subdivided into 3 groups according to their experience of falls, during the past 2 year period. Among them, 30 persons had no previous experience, 20 had one fall, and 20 more than one fall. Age, past history, situations surrounding falls, MMSE K, GDS short form, ADL, IADL, Mini Nutritional assessment (MNA) were reviewed, and the Get up and go test, evaluation of orthostic hypotension and hearing were done. T-test, chi square, ANOVA, logistic regression test using the SAS program was performed. RESULTS: The mean age of the participants was 75.4 years with 62.9% malas. The factors associated with falling were age (P=0.01), scores of MNA (P=0.04), Get up and go test (P=0.004), past history (P=0.01), MMSE K (P=0.02), GDS short form (P=0.001), ADL (P=0.003) and IADL (P=0.002). Those in the group who fell once occured mostly while doing a riskful task, while those who fell more than once happened mostly during positional change (p<0.0001). Independent predictors of falls were get up and go test results and GDS short form scores. CONCLUSION: The independent predictors of falls were Get up and go test results and Geriatric Depression Scale scores.