| Autor: |
Carvalho APL; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Nardello LCL; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Fernandes FS; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Bruno FP; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Paz LR; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Iglecias EF; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Honório HM; Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru 17012-901, Brazil., Mayer MPA; Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil., Gavini G; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil., Pinheiro ET; Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo 05508-000, Brazil.; Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, CH-8032 Zurich, Switzerland. |
| Abstrakt: |
New tools for activating endodontic irrigants have evolved, yet their impact on root canal disinfection, in comparison to the passive placing of an inter-visit medication, have not yet been fully elucidated. The use of DNA- and rRNA-based methods may cast some new light on this issue, as they allow a comparison to be made between microbial presence and activity. Therefore, the aim of this single-arm intervention trial is to evaluate the antibacterial effect of endodontic procedures using both molecular methods. Root canal samples were obtained from 20 patients with asymptomatic apical periodontitis after each treatment step: access cavity, chemo-mechanical preparation, adjunctive procedures (XP-endo Finisher file and passive ultrasonic irrigation), calcium hydroxide medication, and 2nd-visit root canal preparation. DNA and cDNA from the samples were subjected to quantitative polymerase chain reaction with universal primers for the bacterial 16S rRNA gene. Chemo-mechanical preparation promoted a drastic reduction in bacterial levels and activity, whereas the adjunctive procedures did not make a significant contribution to further disinfection. At the 2nd visit, bacteria were active after the use of calcium hydroxide medication; however, they were significantly reduced after a 2nd-visit preparation. Consequently, the lowest bacterial levels were found at the end of the treatment. This clinical trial, which used an rRNA and rDNA combined approach, confirmed previous studies showing that root canal preparation represents the main strategy for root canal disinfection. |
