title: Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study.
abstract: The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.
authors.affiliation: Department of Dentistry, U Dental Hospital, Seoul, Korea.
authors.forename: Jun Sang
authors.initials: JS
authors.lastname: Yoo
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: Seok-Woo
authors.initials: SW
authors.lastname: Chang
authors.affiliation: Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Korea.
authors.forename: So Ram
authors.initials: SR
authors.lastname: Oh
authors.affiliation: Division of Restorative Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.
authors.forename: Hiran
authors.initials: H
authors.lastname: Perinpanayagam
authors.affiliation: Department of Conservative Dentistry, Jukjeon Dental Hospital, College of Dentistry, Dankook University, Jukjeon, Korea.
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Lim
authors.affiliation: Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Korea.
authors.forename: Yeon-Jee
authors.initials: YJ
authors.lastname: Yoo
authors.affiliation: Department of Dentistry, U Dental Hospital, Seoul, Korea.
authors.forename: Yeo-Rok
authors.initials: YR
authors.lastname: Oh
authors.affiliation: Department of Dentistry, U Dental Hospital, Seoul, Korea.
authors.forename: Sang-Bin
authors.initials: SB
authors.lastname: Woo
authors.affiliation: Department of Oral Microbiology & Immunology, Dental Research Institute and BK21 Program, Seoul National University School of Dentistry, Seoul, Korea.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Han
authors.affiliation: Division of Endodontology, Department of Oral Health and Diagnostic Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, USA.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Korea.
authors.forename: Kee-Yeon
authors.initials: KY
authors.lastname: Kum
mesh_terms: D017607:Aluminum Compounds / Q000627:therapeutic use*; D002113:Calcification, Physiologic / Q000502:physiology; D017610:Calcium Compounds / Q000627:therapeutic use*; D003460:Crystallization; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003804:Dentin / Q000382:microbiology*; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000648:ultrastructure*; D006801:Humans; D008768:Methylmethacrylates / Q000627:therapeutic use; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000627:therapeutic use*; D012387:Root Canal Filling Materials / Q000627:therapeutic use*; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation; D017640:Silicates / Q000627:therapeutic use*; D013997:Time Factors; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D008768:Methylmethacrylates; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; D015035:Zinc Oxide-Eugenol Cement; C086631:mineral trioxide aggregate; C031667:IRM cement