title: Clinical relevance of trans 1,4-polyisoprene aging degradation on the longevity of root canal treatment.
abstract: This in vivo study investigated the time of degradation of root filling material (trans 1,4-polyisoprene) retrieved from endodontically treated teeth and correlated the occurrence of degradation with the longevity of endodontics. Thirty-six root-filled teeth with different filling times (2 to 30 years) and with and without periapical lesions were selected. All teeth presented clinical indication for root canal retreatment. The association among filling time, presence of periapical lesion and root filling material degradation was investigated. Root filling samples were retrieved from the root canals using a Hedströ m file without solvent. The trans 1,4-polyisoprene was isolated by root filling solubilization in chloroform followed by filtration and centrifugation. GPC and FT-IR were the analytical techniques utilized. Degradation of trans 1,4-polyisoprene occurred with time, as a slow process. It is an oxidative process, and production of carboxyl and hydroxyl groups in the residual polymer were observed. Statistically significant decrease of molar mass was observed after 5 (p=0.0001) and 15 (p=0.01) years in teeth with and without periapical lesion, respectively. Bacteria participated in polymer degradation. Gutta-percha aging was proven an important factor for the long-term success of endodontic treatment. The findings of the present study showed that, after 15 years, polymer weight loss may decrease the capacity of the filling mass to seal the root canal space and prevent re-infection, thus compromising significantly the longevity of root canal therapy.
authors.affiliation: Department of Endodontics, School of Dentistry, University of Fortaleza, Fortaleza, CE, Brazil. maniglia@unifor.br
authors.forename: Cláudio
authors.initials: C
authors.lastname: Maniglia-Ferreira
authors.forename: Guilherme Bönecker
authors.initials: GB
authors.lastname: Valverde
authors.forename: João Batista Araújo
authors.initials: JB
authors.lastname: Silva
authors.forename: Regina Célia Monteiro
authors.initials: RC
authors.lastname: de Paula
authors.forename: Judith Pessoa Andrade
authors.initials: JP
authors.lastname: Feitosa
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: de Souza-Filho
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D002244:Carbon / Q000032:analysis; D002498:Centrifugation; D055598:Chemical Phenomena; D002725:Chloroform / Q000737:chemistry; D002850:Chromatography, Gel; D003786:Dental Pulp Cavity / Q000382:microbiology; D005374:Filtration; D006171:Gutta-Percha / Q000737:chemistry; D045782:Hemiterpenes / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D006878:Hydroxides / Q000032:analysis; D007840:Latex / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D010485:Periapical Periodontitis / Q000382:microbiology / Q000628:therapy; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000032:analysis / Q000737:chemistry*; D012389:Root Canal Obturation; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D045782:Hemiterpenes; D006878:Hydroxides; D007840:Latex; D012387:Root Canal Filling Materials; D012997:Solvents; D002244:Carbon; D002725:Chloroform; D006171:Gutta-Percha; C455100:1,4-polyisoprene; C031356:hydroxide ion; D010100:Oxygen