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Type: Artigo de periódico
Title: In vivo aging of gutta-percha dental cone
Author: Silva, JBA
de Paula, RCM
Feitosa, JPA
Gurgel, ED
Maniglia-Ferreira, C
de Souza, FJ
Abstract: Gutta-percha cone is the most widely used material for root canal filling. The in vivo aging of this cone focus on the degradation of its main organic component, trans-1,4-polyisoprene, was studied. Aged cones (25 samples) from 2 to 30 years of root canal filling were extracted from different patients in the occasion of retreatment by mechanical way. The information about the aging time was given by the patients. Gel-permeation chromatography (GPC) and infrared spectroscopy (FTIR) were the analytical techniques used. Polyisoprene degrades with time of aging, but in a slow process. Decrease in polymer molar mass from 5.7 X 10(5) to 1.7 X 10(5) g/mol was observed in polyisoprene from cone after 30 years of root canal filling and inside a noninfected tooth. In tooth with caries and periodontal infection, the decrease in molar mass is higher (4.6 X 10(4) g/mol in cone with 10 years of aging). The production of carbonyl and hydroxyl groups in the aged material indicates that the process is oxidative, even in closed teeth. in these cases, the oxygen could be provided from tissue fluid. The degradation mechanism is complex and depends on many factors, besides time of root canal filling. The dental problem caused by the aging could be the production and migration of cytotoxic substances to periodontal ligament and the reduction on the canal sealing property due to the polymer weight loss. Both of them could contribute to the root canal treatment failure. (c) 2006 Wiley Periodicals, Inc.
Subject: rubber
dental polymers
Country: EUA
Editor: John Wiley & Sons Inc
Citation: Journal Of Applied Polymer Science. John Wiley & Sons Inc, v. 100, n. 5, n. 4082, n. 4088, 2006.
Rights: fechado
Identifier DOI: 10.1002/app.23272
Date Issue: 2006
Appears in Collections:Unicamp - Artigos e Outros Documentos

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