Abstract Title of Thesis: In Vivo Evaluation of Contemporary Endodontic Antimicrobial Procedures

Title of Thesis: In Vivo Evaluation of Contemporary Endodontic Antimicrobial Procedures Peter Bellingham, Master of Science, 2011 Thesis Directed by: Dr. Ashraf F. Fouad, Professor and Chairman, Director of Postgraduate Endodontics, University of Maryland School of Dentistry Introduction: Clinical assessment of the efficacy of novel root canal disinfection protocols is an important focus in endodontic research. The purpose of this randomized, masked study was to: (1) Determine and compare the incidence of bacterial DNA and growth after final rinse with MTAD or 5.25% NaOCl by conventional syringe irrigation and ultrasonic irrigation, and (2) Determine and compare colony forming units and incidence of bacterial DNA and growth before and after ProUltra PiezoFlow ultrasonic irrigation. Methods: Canals in 20 teeth (single-rooted) were prepared using 5.25% NaOCl and 17% EDTA, then rinsed with MTAD or 5.25% in random sequence by conventional syringe and ultrasonically-activated irrigation, medicated for 7 days with Ca(OH)2, and filled. Root canal samples were obtained before (A) preparation, after final rinse conventional syringe needle irrigation (B), and after final rinse ultrasonically-activated irrigation (C). Samples were evaluated for incidence of bacterial DNA using PCR amplification of the bacterial 16S rRNA gene.Incidence of bacterial DNA. Additionally, incidence of bacterial growth and colony counts was determined after 10 days of anaerobic incubation. Results: Incidence of bacterial DNA and bacterial growth did not differ significantly between final rinse MTAD and 5.25% NaOCl groups, both after conventional syringe and ultrasonically-activated irrigation. Incidence of bacterial growth was significantly less after ultrasonically-activated irrigation, and a trend was observed towards reduction in colony count. Conclusion: The results of this randomized, masked study did not show a significant short-term antimicrobial advantage of final rinse MTAD over 5.25% NaOCl. Ultrasonically-activated irrigation demonstrated a significant reduction in the incidence of bacterial growth and a trend towards reduction in colony counts. Bacterial presence before obturation can adversely affect the outcome of treatment. The results of this study could provide direction for new irrigation techniques to improve outcomes for the endodontic treatment of teeth. In Vivo Evaluation of Contemporary Endodontic Antimicrobial Procedures