title: Promotion of endodontic lesions in rats by a novel extraradicular biofilm model using obturation materials.
abstract: Although extraradicular biofilm formation is related to refractory periapical periodontitis, the mechanism of extraradicular biofilm development, as well as its effect on periapical lesions, is unknown. Therefore, we aimed to develop an in vivo extraradicular biofilm model in rats and to identify and quantify extraradicular biofilm-forming bacteria while investigating the effect of extraradicular biofilms on periapical lesions. Periapical lesions were induced by exposing the pulpal tissue of the mandibular first molars of male Wistar rats to their oral environment. Four weeks later, gutta-percha points were excessively inserted into the mesial root canals of the right first molars (experimental sites) but not the left first molars (control sites). After 6 and 8 weeks of pulp exposure, the presence of extraradicular biofilms was confirmed histomorphologically, and biofilm-forming bacteria were identified by using classical culture methods. The biofilms were observed in the extraradicular area of the experimental sites. Similar species were detected both inside and outside the root canals. The bacterial count, quantified by real-time PCR assays, in the extraradicular area gradually increased in the experimental sites until 20 weeks after pulp exposure. After 8 weeks of pulp exposure, the periapical lesion volume that was measured by micro-computed tomography was significantly larger in the experimental sites than in the control sites (P < 0.05 by Welch's t test). These results suggest that we developed an extraradicular biofilm model in rats and that extraradicular biofilms affect developing periapical lesions.
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Katsutaka
authors.initials: K
authors.lastname: Kuremoto
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan noiri@dent.osaka-u.ac.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Noiri
authors.affiliation: Division of Materials and Manufacturing Science, Osaka University Graduate School of Engineering, Suita, Osaka, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Ishimoto
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Naomichi
authors.initials: N
authors.lastname: Yoneda
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Yamamoto
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Hazuki
authors.initials: H
authors.lastname: Maezono
authors.affiliation: Division of Materials and Manufacturing Science, Osaka University Graduate School of Engineering, Suita, Osaka, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Nakano
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Ebisu
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000382:microbiology* / Q000473:pathology; D058491:Bacterial Load; D018407:Bacterial Physiological Phenomena; D018441:Biofilms / Q000254:growth & development*; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004195:Disease Models, Animal; D010483:Periapical Diseases / Q000382:microbiology* / Q000473:pathology; D017208:Rats, Wistar; D014057:Tomography, X-Ray Computed; D014092:Tooth Root / Q000382:microbiology*
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Feb;101(2):239-49
references.pmid: 16448928
references.citation: Crit Rev Oral Biol Med. 2004 Nov 01;15(6):348-81
references.pmid: 15574679
references.citation: Lancet. 2001 Jul 14;358(9276):135-8
references.pmid: 11463434
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998 Jan;85(1):86-93
references.pmid: 9474621
references.citation: J Antimicrob Chemother. 2014 Feb;69(2):416-27
references.pmid: 24078467
references.citation: Oral Microbiol Immunol. 1994 Jun;9(3):129-35
references.pmid: 7936717
references.citation: Infect Immun. 2010 Nov;78(11):4560-9
references.pmid: 20805334
references.citation: J Immunol. 2011 Jan 15;186(2):869-77
references.pmid: 21149611
references.citation: J Endod. 2013 May;39(5):648-52
references.pmid: 23611384
references.citation: Cell Host Microbe. 2011 Nov 17;10(5):497-506
references.pmid: 22036469
references.citation: J Periodontal Res. 2010 Apr;45(2):255-61
references.pmid: 19778324
references.citation: J Endod. 2010 Aug;36(8):1277-88
references.pmid: 20647081
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Nov;108(5):796-805
references.pmid: 19734073
references.citation: J Control Release. 2013 Dec 28;172(3):1035-44
references.pmid: 24140747
references.citation: Microbiol Immunol. 2009 May;53(5):287-94
references.pmid: 19457170
references.citation: J Appl Microbiol. 2012 Feb;112(2):404-11
references.pmid: 22093286
references.citation: Oral Surg Oral Med Oral Pathol. 1975 Feb;39(2):304-17
references.pmid: 1054456
references.citation: Microsc Res Tech. 2013 Sep;76(9):979-83
references.pmid: 23857917
references.citation: J Endod. 1994 Jan;20(1):13-7
references.pmid: 8182380
references.citation: Int Endod J. 2003 Jan;36(1):1-11
references.pmid: 12656508
references.citation: J Endod. 2002 Oct;28(10):679-83
references.pmid: 12398163
references.citation: Jpn J Exp Med. 1978 Apr;48(2):167-76
references.pmid: 713124
references.citation: J Endod. 2002 Apr;28(4):304-10
references.pmid: 12043869
references.citation: Am J Clin Pathol. 1966 Oct;46(4):472-4
references.pmid: 4162586
references.citation: J Endod. 2013 Aug;39(8):984-9
references.pmid: 23880264
references.citation: Proc Natl Acad Sci U S A. 2007 May 22;104(21):9047-51
references.pmid: 17502606
references.citation: J Endod. 2003 Apr;29(4):252-6
references.pmid: 12701773
references.citation: Oral Surg Oral Med Oral Pathol. 1965 Sep;20:340-9
references.pmid: 14342926
references.citation: Appl Environ Microbiol. 2005 Dec;71(12):8738-43
references.pmid: 16332869
references.citation: Antimicrob Agents Chemother. 2011 Dec;55(12):5887-92
references.pmid: 21911560
references.citation: J Dent Res. 1980 Jan;59(1):87-96
references.pmid: 6927990
references.citation: Oral Microbiol Immunol. 2004 Apr;19(2):71-6
references.pmid: 14871344
references.citation: J Endod. 1996 Aug;22(8):418-21
references.pmid: 8941751
references.citation: J Endod. 2002 Dec;28(12):815-8
references.pmid: 12489650
references.citation: Int Endod J. 1998 Nov;31(6):394-409
references.pmid: 15551607
references.citation: J Endod. 1994 Jan;20(1):27-31
references.pmid: 8182383
references.citation: J Endod. 1983 Feb;9(2):71-5
references.pmid: 6590767
references.citation: J Dent Res. 2003 Apr;82(4):322-5
references.pmid: 12651940
references.citation: J Endod. 1987 Nov;13(11):535-40
references.pmid: 3482098
references.citation: J Endod. 1992 May;18(5):216-27
references.pmid: 1402575
references.citation: Eur J Oral Sci. 2004 Dec;112(6):523-9
references.pmid: 15560836
references.citation: J Dent Res. 1989 May;68(5):830-4
references.pmid: 2523917
references.citation: J Dent Res. 2004 Sep;83(9):683-7
references.pmid: 15329372