C M Sedgley1, S L Lennan, O K Appelbe. 1. Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA. csedgley@umich.edu
Abstract
AIM: The hypotheses tested in this study were that: (i) Enterococcus faecalis can survive long-term entombment in root filled teeth without additional nutrients, (ii) initial cell density influences the survival of E. faecalis in instrumented root canals and (iii) gelatinase-production capacity influences the survival of E. faecalis in root canals. METHODOLOGY: The root canals of 150 extracted single canal teeth were instrumented to apical size 60 and divided into six groups of 25. Within each group 10 canals were inoculated with either gelatinase-producing E. faecalis OG1-S and the other 10 with its gelatinase-defective mutant E. faecalis OG1-X. Five canals per group were kept as uninoculated controls. The root canals in groups 1 and 2 were inoculated with 10(6) bacteria, incubated for 48 h at 37 degrees C then filled with gutta-percha and zinc-oxide eugenol sealer. Root canals were inoculated with 10(6), 10(5), 10(4) and 10(3) bacteria in groups 3-6, respectively, and left unfilled. All teeth were sealed coronally with glass-ionomer cement. After 6- (groups 1, 3-6) and 12-month (group 2) incubation at 37 degrees C in 100% humidity, root fragments were analysed for presence of E. faecalis, using culture, polymerase chain reaction and histological methods. RESULTS: Viable E. faecalis was recovered from all root filled teeth and from 95-100% of unfilled inoculated teeth. Initial cell density and gelatinase production did not influence the recovery of viable E. faecalis (P > 0.05; chi-square test). Enterococcus faecalis 16S rRNA gene products were present in all inoculated teeth and absent in all noninoculated controls. Dentinal tubule infection was evident under light microscopy in sections from inoculated teeth after 48-h, 6- and 12-month incubation. CONCLUSIONS: Enterococcus faecalis inoculated into root canals maintained viability for 12-months ex vivo. The clinical implications are that viable E. faecalis entombed at the time of root filling could provide a long-term nidus for subsequent infection.
AIM: The hypotheses tested in this study were that: (i) Enterococcus faecalis can survive long-term entombment in root filled teeth without additional nutrients, (ii) initial cell density influences the survival of E. faecalis in instrumented root canals and (iii) gelatinase-production capacity influences the survival of E. faecalis in root canals. METHODOLOGY: The root canals of 150 extracted single canal teeth were instrumented to apical size 60 and divided into six groups of 25. Within each group 10 canals were inoculated with either gelatinase-producing E. faecalis OG1-S and the other 10 with its gelatinase-defective mutant E. faecalis OG1-X. Five canals per group were kept as uninoculated controls. The root canals in groups 1 and 2 were inoculated with 10(6) bacteria, incubated for 48 h at 37 degrees C then filled with gutta-percha and zinc-oxide eugenol sealer. Root canals were inoculated with 10(6), 10(5), 10(4) and 10(3) bacteria in groups 3-6, respectively, and left unfilled. All teeth were sealed coronally with glass-ionomer cement. After 6- (groups 1, 3-6) and 12-month (group 2) incubation at 37 degrees C in 100% humidity, root fragments were analysed for presence of E. faecalis, using culture, polymerase chain reaction and histological methods. RESULTS: Viable E. faecalis was recovered from all root filled teeth and from 95-100% of unfilled inoculated teeth. Initial cell density and gelatinase production did not influence the recovery of viable E. faecalis (P > 0.05; chi-square test). Enterococcus faecalis 16S rRNA gene products were present in all inoculated teeth and absent in all noninoculated controls. Dentinal tubule infection was evident under light microscopy in sections from inoculated teeth after 48-h, 6- and 12-month incubation. CONCLUSIONS:Enterococcus faecalis inoculated into root canals maintained viability for 12-months ex vivo. The clinical implications are that viable E. faecalis entombed at the time of root filling could provide a long-term nidus for subsequent infection.
Authors: Andrea Ardizzoni; Luigi Generali; Elena Righi; Maria C Baschieri; Francesco Cavani; Lidia Manca; Eleonora Lugli; Luigi Migliarese; Elisabetta Blasi; Rachele G Neglia Journal: Odontology Date: 2013-07-09 Impact factor: 2.634
Authors: Anna Ossmann; Stefan Kranz; Guellmar Andre; Andrea Völpel; Volker Albrecht; Alfred Fahr; Bernd W Sigusch Journal: Clin Oral Investig Date: 2014-06-21 Impact factor: 3.573
Authors: Luis E Chávez de Paz; José A Lemos; Claes Wickström; Christine M Sedgley Journal: Appl Environ Microbiol Date: 2011-12-16 Impact factor: 4.792
Authors: Qinghong Ran; Brian D Badgley; Nicholas Dillon; Gary M Dunny; Michael J Sadowsky Journal: Appl Environ Microbiol Date: 2013-03-01 Impact factor: 4.792
Authors: Peter J Moses; Daniel A Power; Amy M Jesionowski; Howard F Jenkinson; Eugene A Pantera; M Margaret Vickerman Journal: J Endod Date: 2012-07-07 Impact factor: 4.171
Authors: Blanca Blancas; María de Lourdes Lanzagorta; Luis Felipe Jiménez-Garcia; Reyna Lara; José Luis Molinari; Ana María Fernández Journal: Clin Exp Dent Res Date: 2021-05-05