Division of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK.
Leeds Dental Institute, Leeds Teaching Hospitals Trust, Leeds, UK.
J Dent Res. 2021 Dec;100(13):1461-1467. doi: 10.1177/00220345211032885. Epub 2021 Aug 2.
Limiting infection transmission is central to the safety of all in dentistry, particularly during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Aerosol-generating procedures (AGPs) are crucial to the practice of dentistry; it is imperative to understand the inherent risks of viral dispersion associated with AGPs and the efficacy of available mitigation strategies. In a dental surgery setting, crown preparation and root canal access procedures were performed with an air turbine or high-speed contra-angle handpiece (HSCAH), with mitigation via rubber dam or high-volume aspiration and a no-mitigation control. A phantom head was used with a 1.5-mL min flow of artificial saliva infected with Φ6-bacteriophage (a surrogate virus for SARS-CoV-2) at ~10 plaque-forming units mL, reflecting the upper limits of reported salivary SARS-CoV-2 levels. Bioaerosol dispersal was measured using agar settle plates lawned with the Φ6-bacteriophage host, . Viral air concentrations were assessed using MicroBio MB2 air sampling and particle quantities using Kanomax 3889 GEOα counters. Compared to an air turbine, the HSCAH reduced settled bioaerosols by 99.72%, 100.00%, and 100.00% for no mitigation, aspiration, and rubber dam, respectively. Bacteriophage concentrations in the air were reduced by 99.98%, 100.00%, and 100.00% with the same mitigations. Use of the HSCAH with high-volume aspiration resulted in no detectable bacteriophage, both on nonsplatter settle plates and in air samples taken 6 to 10 min postprocedure. To our knowledge, this study is the first to report the aerosolization in a dental clinic of active virus as a marker for risk determination. While this model represents a worst-case scenario for possible SARS-CoV-2 dispersal, these data showed that the use of HSCAHs can vastly reduce the risk of viral aerosolization and therefore remove the need for clinic fallow time. Furthermore, our findings indicate that the use of particle analysis alone cannot provide sufficient insight to understand bioaerosol infection risk.
限制感染传播是牙科安全的核心，尤其是在当前严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）大流行期间。产生气溶胶的程序（AGPs）对牙科实践至关重要；了解与 AGPs 相关的病毒扩散的固有风险以及可用缓解策略的效果至关重要。在牙科手术环境中，使用空气涡轮机或高速手机（HSCAH）进行牙冠预备和根管进入程序，通过橡皮障或大体积抽吸和无缓解对照来减轻。使用带有 1.5 毫升/分钟人工唾液的人工头颅，该唾液中感染了 Φ6-噬菌体（SARS-CoV-2 的替代病毒），约为 10 个噬菌斑形成单位/毫升，反映了报告的唾液 SARS-CoV-2 水平的上限。使用带有 Φ6-噬菌体宿主的琼脂沉降平板测量生物气溶胶分散， 。使用 MicroBio MB2 空气采样评估病毒空气浓度，并使用 Kanomax 3889 GEOα计数器评估颗粒数量。与空气涡轮机相比，对于无缓解、抽吸和橡皮障，HSCAH 将沉降生物气溶胶分别减少了 99.72%、100.00%和 100.00%。在相同的缓解措施下，空气中的噬菌体浓度分别降低了 99.98%、100.00%和 100.00%。使用 HSCAH 进行大体积抽吸，在非飞溅沉降平板和程序后 6 至 10 分钟采集的空气样本中均未检测到噬菌体。据我们所知，这项研究首次报告了在牙科诊所中使用活性病毒作为风险确定标志物的气溶胶化。虽然该模型代表了 SARS-CoV-2 可能扩散的最坏情况，但这些数据表明，使用 HSCAHs 可以大大降低病毒气溶胶化的风险，因此无需进行诊所闲置时间。此外，我们的研究结果表明，仅使用颗粒分析无法提供足够的洞察力来了解生物气溶胶感染风险。
