PURPOSE: The aim of this study is to evaluate the effectiveness of MnO₂-diatom microbubbler (DM) on the surface of prosthetic materials as a mouthwash by comparing the biofilm removal effect with those previously used as a mouthwash in dental clinic.MATERIALS AND METHODS: DM was fabricated by doping manganese dioxide nanosheets to the diatom cylinder surface. Scanning electron microscopy (SEM) was used to observe the morphology of DM and to analyze the composition of doped MnO₂. Stereomicroscope was used to observe the reaction of DM in 3% hydrogen peroxide. Non-precious metal alloys, zirconia and resin specimens were prepared to evaluate the effect of biofilm removal on the surface of prosthetic materials. And then Streptococcus mutans and Porphyromonas gingivalis biofilms were formed on the specimens. When 3% hydrogen peroxide solution and DM were treated on the biofilms, the decontamination effect was compared with chlorhexidine gluconate and 3% hydrogen peroxide solution by crystal violet staining.RESULTS: Manganese dioxide was found on the surface of the diatom cylinder, and it was found to produce bubble of oxygen gas when added to 3% hydrogen peroxide. For all materials used in the experiments, biofilms of the DM-treated groups got effectively removed compared to the groups used with chlorhexidine gluconate or 3% hydrogen peroxide alone.CONCLUSION: MnO₂-diatom microbubbler can remove bacterial membranes on the surface of prosthetic materials more effectively than conventional mouthwashes.
Alloys ; Biofilms ; Chlorhexidine ; Decontamination ; Dental Clinics ; Dental Plaque ; Diatoms ; Gentian Violet ; Hydrogen Peroxide ; In Vitro Techniques ; Manganese ; Membranes ; Microscopy, Electron, Scanning ; Mouthwashes ; Oral Hygiene ; Oxygen ; Porphyromonas gingivalis ; Streptococcus mutans

The article ‘The biofilm removal effect of MnO2-diatom microbubbler from the dental prosthetic surfaces: In vitro study’ authored by Eun-Hyuk Lee,Yongbeom Seo, Ho-Bum Kwon, Young-Jun Yim, Hyunjoon Kong, Myung-Joo Kim, published in April issue [Vol 58, No 1] of The Journal of KoreanAcademy of Prosthodontics (2020), has an erratum.The author names were mistakenly given as Ho-Bum Kwon, Young-Jun Yim. It should be corrected as Ho‐Beom Kwon, Young‐Jun Lim. The Journal ofKorean Academy of Prosthodontics apologizes to the readers for this error.

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.