Evaluation of the Waterline Biofilm Improvement in Dental Units

評估牙科治療台水路生物膜改善流程

生物膜生成在牙科治療台水線(DUWL) 內是一個常見問題。我們試圖建置一個經濟、有效且可持續的消毒流程來減少總細菌數(TBC) 和感染。使用平板塗抹法進行細菌培養數據分析及使用BRUKER MALDI-TOF 鑑定細菌種類，並提出四種改善流程以分析生物膜形成的原因。DUWL 微生物包括假血鞘氨醇單胞菌、皮蒂不動桿菌、水泡短單胞菌、近平滑念珠菌和芽孢桿菌等。結果表示，使用1.41% H2O2和1000ppm次氯酸水進行衝擊消毒(改善流程III) 和加強水線前端餘氯監測（改善流程IV）可以有效改善DUWL中的TBC (p<0.05)。此外，高速手機和低速手機的TBC存在顯著差異(p<0.05)，主要的原因是因為高速降速空氣回吸會將微生物引入高速手機。另外，病患人數與TBC 之間沒有相關性。所以，建立有效的消毒流程以及加強水線前端餘氯監測對於有效去除有害病原體尤為重要。

Biofilm formation in the dental unit waterline (DUWL) is a common problem. We tried to achieve an economical, effective, and sustainable process to reduce the total bacteria count (TBC) and infection. The bacterial culture data were analyzed by the spread plate method and identification of bacterial species using BRUKER MALDI-TOF. To analyze the causes of biofilm formation, four improvement procedures were proposed. The DUWL microorganisms include Sphingomonas pseudosanguinis, Acinetobacter pittii, Brevundimonas vesicularis, Candida parapsilosis, and Bacillus. The results showed that using 1.41% H2O2 and 1000ppm of hypochlorous acid for shock disinfection (process III) and strengthening the monitoring of residual chlorine at the front end of the waterline (process IV) could effectively improve the TBC in DUWL (p<0.05). In addition, the TBC was significantly different between the high and low speed of the handpieces (p<0.05), and the deceleration and suction were the main reason for the introduction of microorganisms into the high-speed handpieces. No correlation between the number of visits and the TBC was found. It is particularly important to establish a disinfection process and strengthen the monitoring of residual chlorine at the front end of the waterline to effectively remove harmful pathogens.