歯科治療後のエアロゾル中のSARS-CoV-2の存在調査

Investigation of the Presence of SARS-CoV-2 in Aerosol After Dental Treatment.

抄録

目的:

本研究の目的は，超音波スケーリングおよび歯面清掃に伴うエアロゾル中のSARS-CoV-2の存在およびCOVID-19汚染距離について調査することである。

AIMS: The objective of the present study was to investigate the presence of SARS-CoV-2 in aerosol and COVID-19 contamination distance asssociated with ultrasonic scaling and tooth preparation.

方法:

COVID-19の患者24名を本研究の対象とした。超音波処置具による歯肉縁上歯垢除去を10分間，丸型ダイヤモンドバーによる上顎右側犬歯の切削を想定した高速エアタービンを5分間実施した．患者を2群に無作為に割り付けた．A群では，治療時に中容量吸引を行った．B群では，中容量吸引にエアゾールカニューレを用いた高容量吸引を追加した．治療前に、ウイルス輸送用培地を入れたガラスシャーレ5枚を手術室に設置した。治療後，シャーレは直ちに微生物学研究室に運ばれ，リアルタイムポリメラーゼ連鎖反応（RT-PCR）分析が行われた．

METHODS: Twenty-four patients with COVID-19 were included in this study. Removal of supragingival plaque with ultrasonic instruments for 10 minutes and high-speed air-turbine using for the simulation of cutting the maxillary right canine tooth with a round diamond bur for 5 minutes were performed. Patients were randomly assigned to 2 groups: In group A, medium-volume suction was used during treatment. In group B, high-volume suction with an aerosol cannula was added to medium-volume suction. Prior to treatment, 5 glass petri dishes containing viral transport medium were placed in the operating room. After treatment, petri dishes were immediately delivered to a microbiology laboratory for real-time polymerase chain reaction (RT-PCR) analysis.

結果:

RT-PCR検査の結果，B群では全検体で陰性であったが，A群では5検体でCOVID-19の陽性反応が検出された．

RESULTS: RT-PCR test results were negative for all specimens in group B. However, 5 positive test results for COVID-19 were detected in group A specimens.

結論:

エアロゾルによるCOVID-19ウイルス汚染を防ぐには，エアロゾルカニューラによる吸引が非常に重要である．また，吸引量（風量）は150 mm Hgまたは325 L/minの高容量吸引で十分なウイルス汚染除去が可能であった．したがって，COVID-19患者の歯科治療では，大量の吸引を行う必要がある．

CONCLUSIONS: Suction with an aerosol cannula is very important to prevent COVID-19 viral contamination via aerosol. In addition, a high-volume suction capacity (air volume) of 150 mm Hg or 325 L/min is sufficient for elimination of viral contamination. Thus, high-volume suction should be used during dental treatments in COVID-19 patients.