본 연구의 목적은 규조류 복합체의 active micro-locomotion을 이용한 의치 세척력 효력을 식품의약품안전처 의치∙치아교정기 세정제 효력평가법 가이드라인에 의거하여 평가하고, 기존 의치세정제들과 비교하여 세정 효과를 알아보는 것이다.
상용되는 의치 세정제를 제조하는 회사들은 의치를 세정액에 담근 후 기계적 칫솔질을 동반하여 세척할 것을 권고하는데, 거동이 불편한 고령의 환자들이 스스로 이를 시행하기는 어려우며 요양병원과 같은 집단거주시설에서 개별적인 의치의 기계적 세정을 기대하기는 힘든 경우가 많다. 따라서, 이를 개선하기 위해 self-motile이라는 독특한 특성을 가진 이산화망간(MnO2)을 코팅한 규조류 복합체를 의치 세정에 적용하여 기계적, 화학적 세정의 효과를 동시에 얻어보고자 하였다.
인공타액은 American National Standard/American Dental Association Specification No. 41 Recommended Standard – Practices for Biological Evaluation of Dental Materials에서 제시한 조건에 따라 조제한 후, 세포 배양용 96-well plate에 100 µL씩 분주하여 50 ± 2 ℃의 건조기에서 12시간 동안 건조하였다. 흡광도의 범위가 0.4 이상의 값이 되면 양성대조군(10~15% NaOCl), 음성대조군(증류수), 실험군들(규조류 복합체 A(Aulacoseira, MnO2-polydopamine (PDA)-A), 규조류 복합체 M (Melosira nummuloides, MnO2-chitosan(CS)-M), Polident (Polident 5minutes quick plus, GlaxoSmithKline, Dungarvan, Ireland), Dentfix-forte (Helago-Phama GmbH&Co., Parchim, Germany), 아리수(서울시 수돗물), 정수기물을 준비하였다. 규조류 복합체 A, M군들은 다시 규조류 함량과 과산화수소 농도에 따라 A1, M1(규조류 2mg/ml, 3% H2O2), A2, M2 (규조류 2mg/ml, 6% H2O2), A3, M3 (규조류 4mg/ml, 6% H2O2) 군으로 세분화하였다. 인공타액이 건조된 96-well plate에 실험액을 100 µL씩 분주하고 25 ± 2 ℃에서 10분간 반응시켰다. 검사액을 버리고 PBS (Phosphate buffered saline)로 세척 후 microplate reader로 흡광도(OD 600)를 측정하였다. 세척률은 아래 방법에 따라 계산하였고, 식품의약품안전처의 세정제 효력평가법 가이드라인에 따라 70% 이상이면 ‘세척력 효력’이 있다고 판정하였다.
그 결과, 평균 세척률은 양성대조군(10~15% NaOCl)에서 93.8±1.0%, 음성대조군(증류수)에서 79.1±1.5%로 나타났고, 규조류 복합체 군들에서는 A1 79.8±4.5%, A2 64.7±5.5%, A3 81.9±7.9%, M1 88.5±3.6%, M2 75.8±4.0%, M3 84.5±4.5%로 나타났다. 나머지 실험군들에서는 Polident 88.2±1.2%, Dentfix-forte 83.3±3.0%, 정수기물 81.0±3.4%, 아리수 77.9±2.1%로 나타났다. A2를 제외한 모든 군들에서 70% 이상의 세척률을 나타내어 세척력 효력이 있는 것으로 판명되었으며, 양성대조군을 제외한 군들 중 M1이 88.5 ± 3.5%로 세척 효과가 가장 우수하였다(F=190.141).
세정 효과의 군간 비교를 위해 SPSS 29.0(SPSS, Chicago, IL, USA) 통계 프로그램을 이용하였으며, one-way ANOVA 와 Bonferroni correction으로 사후검정을 시행하여 통계적 유의성을 검정하였다(p<0.05).
규조류 복합체의 active micro-locomotion을 이용한 세정 효과가 시판중인 의치 세정제에 상응하는 결과를 보이므로 세척력 효력이 있는 것으로 평가되며, 보다 높은 세정 효과를 위한 최적의 적용 조건은 추가적인 연구가 필요할 것으로 사료된다.

The purpose of this study was to assess the denture cleaning effects of diatom complexes, which employ active micro-locomotion in the cleaning process. The study aimed to quantify and evaluate the clinical efficacy of diatom complexes as conventional denture cleaning agents using the Korea Food & Drug Administration’s Denture & Orthodontic Appliances Cleaning Agents Assessment Guidelines, ultimately attempting to produce a comparative analysis between the cleaning effects of diatom complexes versus conventional denture cleaning agents.
Manufacturers of conventional denture cleaning agents recommend a two- step cleaning process of first immersing the denture in the chemical cleaning solution followed by rigorous manual brushing. However, such instructions that require repeated physical labor are inaccessible to denture users such as elderly patients who experience partial or complete loss of mobility, or residents of group care facilities like nursing homes, where detailed brushing by hand for each individual denture may not be an option. In seeking to reform existing denture cleaning methods by making denture cleaning accessible to everyone, this study aimed to merge the chemical and manual steps of existing denture cleaning methods into a one-step process by incorporating diatom complexes, as the complexes’ manganese dioxide (MnO2) coating enables them to be uniquely ‘self-motile’.
To conduct the study, artificial saliva was prepared according to the conditions suggested by the American National Standard/American Dental Association Specification No. 41 Recommended Standard – Practices for Biological Evaluation of Dental Materials and distributed into 96-well cell cultivation plates with 100 µL of prepared saliva in each plate. The specimens were then dried in a drying machine at 50 ± 2 ℃ for 12 hours. When the Optical Density(OD) range value came to 0.4 or higher, the following materials were prepared: a positive control group (10~15% NaOCl), a negative control group (distilled water), experimental groups of diatom complex A (Aulacoseira, MnO2-polydopamine(PDA)-A), diatom complex M (Melosira nummuloides, MnO2-chitosan(CS)-M), denture cleaning agent Polident (Polident 5minutes quick plus, GlaxoSmithKline, Dungarvan, Ireland), denture cleaning agent Dentfix-forte (Helago-Phama GmbH&Co., Parchim, Germany), Arisu (tap water in Seoul), and purified water. The experimental groups “diatom complex A” and “diatom complex M” were further split into a total of six subgroups based on diatom content and hydrogen peroxide concentration: test groups A1 and M1 (diatom 2mg/ml, H2O2 3%), test groups A2 and M2 (diatom 2mg/ml, H2O2 6%), and test groups A3 and M3 (diatom 4mg/ml, H2O2 6%).
A 100 µL sample of each group was distributed into the 96-well plates containing dried artificial saliva, and the reactions were induced at 25 ± 2 ℃ for 10 minutes. After the reaction, the test solutions were disposed of and the plates were cleaned with PBS (Phosphate Buffered Saline), then measured for Optical Density (OD 600) with the microplate reader. The cleaning rates were calculated using the formula below. This study awarded the test group with having “potent cleaning power” when the group scored a cleaning rate of 70% or higher on the Korea Food & Drug Administration’s guidelines.
A comparative comprehension of cleaning rates between groups was conducted using the statistics program SPSS 29.0(SPSS, Chicago, IL, USA), followed by a thorough review of the study’s statistical significance using one-way ANOVA and Bonferroni Correction (p<0.05).
The results of the experiment showed that the average cleaning rate of the positive control group (10~15%, NaOC1) was 93.8±1.0%, while the negative control group (distilled water) had a cleaning rate of 79.1±1.5%. Among the diatom complex test groups, the cleaning rates measured at 79.8±4.5% for A1, 64.7±5.5% for A2, 81.9±7.9% for A3, 88.5±3.6% for M1, 75.8±4.0% for A2, and 84.5±4.5% for M3. The remaining test groups each displayed cleaning rates of 88.1±1.2% for denture cleaning agent “Polident”, 83.3±2.9% for denture cleaning agent “Dentfix-forte”, 77.9±2.1% for tap water “Arisu”, and 81.0±3.3% for purified water. All groups except diatom complex test group A2 (Aulacoseira, MnO2-polydopamine (PDA)-A, diatom content 2mg/ml, H2O2 concentration 6%), displayed cleaning rates of 70% or higher; therefore, all groups except test group A2 qualify for having "potent cleaning power” as previously defined within this study. Diatom complex test group M1 (Melosira nummuloides, MnO2-chitosan (CS)-M, diatom content 2mg/ml, H2O2 concentration 3%) had the most powerful cleaning rate of 88.5 ± 3.5% following that of the positive control group (F=190.141).
As the results of this study show, diatom complexes that employ active micro-locomotion cleaning exhibit cleaning rates similar to if not higher than conventional denture cleaning agents, thus enabling the conclusion that diatom complexes possess potent cleaning power that can be harnessed to improve the denture cleaning process. Further studies need to be conducted to pin down the specific optimal conditions that diatom complexes require for peak performance as a cleaning agent and maximum cleaning effect.