赤色発光ダイオードとメチレンブルーを用いた抗菌光線力学療法の口臭軽減効果：微生物学的対照臨床試験

Effect of antimicrobial photodynamic therapy with red led and methylene blue on the reduction of halitosis: controlled microbiological clinical trial.

抄録

赤色発光ダイオード（LED）を用いた抗菌光線力学的療法（aPDT）が、照射直後、照射7日後、14日後、30日後の口臭および舌苔の微生物学的レベルの減少に及ぼす効果を検討する。口臭症と診断された若年成人45名を3群に割り付けた：G1：0.005％メチレンブルーと赤色LEDを用いたaPDT（660nm、4点照射、1点あたり90秒、出力400mW、36J/点、放射照度95J/cm、連続波）、G2：舌削り、G3：舌削りとaPDTの3群に割り付けた。ガスクロマトグラフィーは、治療前と治療直後、および各経過観察時に実施した。同じ時期に舌背から微生物学的サンプルを採取し、リアルタイムPCRqを用いてサンプル中の細菌を定量した。グループ内分析にはWilcoxon検定を、グループ間分析にはKruskal-Wallis検定を用いた。グループ内分析では、すべてのグループで治療前と治療直後に差が認められた（p<0.05）。7日後以降も効果が維持されたのは舌削り群のみであった（p<0.05）。グループ間分析では、グループ間で統計的に有意な差は認められなかった（p>0.05）。赤色LEDと0.005％メチレンブルーを用いたaPDTは、口臭を直ちに減少させたが、その効果は7、14、30日後には維持されなかった。調査した細菌の数や普遍的な16S rRNAの定量に減少はみられなかった。ClinicalTrials.gov Identifier：NCT03656419。

To determine the effect of antimicrobial photodynamic therapy (aPDT) using a red light-emitting diode (LED) on the reduction of halitosis and microbiological levels in the tongue coating immediately after irradiation, 7, 14, and 30 days after treatment. Forty-five young adults diagnosed with halitosis were allocated to three groups: G1, aPDT with 0.005% methylene blue and red LED (660 nm, four irradiation points, 90 s per point, power of 400 mW, 36 J per point, radiant exposure of 95 J/cm, continuous wave); G2, tongue scraping; and G3, tongue scraping and aPDT. Gas chromatography was performed before and immediately after treatment, as well as at the different follow-up times. Microbiological samples were collected at the same times from the dorsum of the tongue, and bacteria were quantified in the samples using real-time PCRq. The Wilcoxon test was used for the intragroup analyses, and the Kruskal-Wallis test was used for the intergroup analyses. In the intragroup analyses, differences were found before and immediately after treatment in all groups (p < 0.05). The effect was maintained after 7 days only in the tongue scraping group (p < 0.05). In the intergroup analysis, no statistically significant differences were found among the groups (p > 0.05). For the microbiological analyses, no statistically significant differences were found in the groups/bacteria that were analyzed (p > 0.05). aPDT using a red LED and 0.005% methylene blue caused an immediate reduction in halitosis, but the effect was not maintained after 7, 14, or 30 days. No reduction occurred in the number of bacteria investigated or the quantification of universal 16S rRNA. ClinicalTrials.gov Identifier: NCT03656419.