Читать книгу Oral Biofilms - Группа авторов - Страница 35

While most DUWLs with functioning water-cleaning systems show few or no bacteria, others still harbor bacteria to an unacceptable level. A 4-year follow-up study [28] showed that the installation of water-cleaning systems (added systems or inbuilt systems) leads to a significant improvement in output water quality. For 1,200 DUWLs at 140 clinics followed between 2013 and 2016, a 95% acceptance of the water quality was attained. The Alpro/Bilpron system was used in the majority of DUWLs (81.6%), but also Oxygenal (2.0%), Unit-Clean (5.2%), Sterilox (0.6%), as well as inbuilt systems (4.8%) were included in 2016. This study did not show any significant differences between the systems. In the remaining 5% of DUWLs that did not reach an acceptable level, the failures could be divided into problems related to the unit or to the clinic. Even if the unit is equipped with a water-cleaning system there is no guarantee of successful results. The most common reason for failure is neglect to run the water-cleaning system regularly. If the bacterial level in the output water is not acceptable, additional cleaning steps have to be taken. It is of outmost importance that the personnel are sufficiently informed and instructed and that necessary precautions are taken for servicing each unit.

Clinic-related problems can also prevail. Examples could be if the building in which the clinic is situated, such as a hospital, has a complex water system, or if the water supply to the clinic is accidentally contaminated with bacteria as a result of renovations and repair. It is recommended that the water in DUWLs is specifically checked after such accidents. Another clinic-related problem is when the clinic has insufficient routines or has chosen an insufficient method for water cleaning.