tailieunhanh - The effect of hydrogen peroxide/colloidal silver on reducing the colonization and growth of heterotrophic bacteria in dental unit waterlines

The objective of the present study was to investigate reduction in the colonization and growth of heterotrophic bacteria in dental unit waterlines by using hydrogen peroxide/colloidal silver as disinfectant. | Turkish Journal of Biology Turk J Biol (2013) 37: 336-341 © TÜBİTAK doi: Research Article The effect of hydrogen peroxide/colloidal silver on reducing the colonization and growth of heterotrophic bacteria in dental unit waterlines* 1, 2 3 1 Meral ÖZALP **, Ömer Engin BULUT , Atilla Stephan ATAÇ , Melike EKİZOĞLU , 1 4 4 Didem KART , Hakan Hamdi ÇELİK , İlkan TATAR 1 Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Hacettepe University, 06100, Sıhhiye, Ankara, Turkey 2 Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Başkent University, 06490, Bahçelievler, Ankara, Turkey 3 Department of Pediatric Dentistry, Faculty of Dentistry, Hacettepe University, 06100, Sıhhiye, Ankara, Turkey 4 Department of Anatomy, Faculty of Medicine, Hacettepe University, 06100, Sıhhiye, Ankara, Turkey Received: Accepted: Published Online: Printed: Abstract: The objective of the present study was to investigate reduction in the colonization and growth of heterotrophic bacteria in dental unit waterlines by using hydrogen peroxide/colloidal silver as disinfectant. Twenty-seven dental units were included; 6 units that were more than 20 years old and 7 units that had been in use for 2 years comprised the old and new treatment groups, respectively. Fourteen units served as controls. The treatment groups were disinfected continuously and every 4 weeks shock doses were applied over a 20-week period. Water samples were taken before treatment, 1 and 2 weeks after treatment, and thereafter every 4 weeks; then they were inoculated onto R2A agar plates. While 1–16-week results for the old treatment group showed total heterotrophic bacterial counts of higher than 1 × 105 cfu/mL, at 20 weeks they were below × 102 cfu/mL. Only 2 units were able to reach levels of ≤200 cfu/ mL, which is the dental unit water quality standard. For the new treatment group .