title: Effect of masticatory cycles on apical leakage of obturated teeth.
abstract: This study investigated the effect of apical leakage due to masticatory cycles on root canal treatment. Twenty upper maxillary molars were first obturated using the warm vertical compaction technique. Four maxillary casts were then built, with each holding four of the sample molars. The molars were embedded in resin with the roots separated from the resin by means of a light silicon. The four remaining teeth served as controls and were not submitted to occlusal forces. A mechanical device to simulate masticatory cycles subjected the teeth to 0.5 x 10(6) cycles (group A), 10(6) cycles (group B), 2 x 10(6) cycles (group C), and 3 x 10(6) cycles (group D); the control was group E. The roots were placed in 2% methylene blue dye solution for 72 h and then sectioned longitudinally so that dye penetration could be measured. The mean values of dye penetration were: 3.70 +/- 0.69 mm, group A; 5.00 +/- 1.14 mm, group B; 6.00 +/- 1.01 mm, group C; 7.23 +/- 0.66 mm, group D; and 2.74 +/- 0.75 mm, group E. The value of dye penetration increased in correlation with the number of masticatory cycles. This in vitro study suggests the significant effect of masticatory loads on apical leakage.
authors.affiliation: Dental School of Montpellier, University of Montpellier, France.
authors.forename: S
authors.initials: S
authors.lastname: Esber
authors.forename: J Y
authors.initials: JY
authors.lastname: Blum
authors.forename: J C
authors.initials: JC
authors.lastname: Chazel
authors.forename: E
authors.initials: E
authors.lastname: Parahy
mesh_terms: D001732:Bite Force; D003763:Dental Leakage / Q000209:etiology; D003799:Dental Stress Analysis; D006801:Humans; D008409:Mastication; D008437:Maxilla; D008963:Molar; D011787:Quality of Health Care; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000592:standards; D019227:Tooth Apex
chemical_list: D012387:Root Canal Filling Materials