title: Apical microleakage of radiolabeled lysozyme over time in three techniques of root canal obturation.
abstract: The three methods of obturation assessed in this study were lateral condensation (80 teeth), Thermafil (40 teeth), and McSpadden (40 teeth). All teeth were prepared to the master apical file 30 and widened coronally by Gates Glidden burs before being randomly assigned to experimental groups to be filled by each technique; they were then sealed with nail polish, except for the apical 1 mm. Quantitative evaluation of apical microleakage for each technique was obtained after periods of 1 day, 7 days, 14 days, and 28 days of immersion in a lysozyme solution labeled with radioactive iodine by preparing horizontal sections of the teeth and measuring the level of radioactivity in each section using a gamma counter. Initial (1-day) leakage was least in the Thermafil group and was significantly different from the other techniques. Leakage was greatest in the laterally condensed samples. By the end of the study (28th day) values for lateral condensation were lowest, but were significantly different only for the McSpadden group. For all techniques leakage was most significant in the first 3 mm from the apex and was very low below this level so that all methods can be considered as giving a hermetic seal below 3 mm.
authors.affiliation: Université Louis Pasteur, Inserm U-424, Faulté de Chirurgie Dentaire, 1 Place de l'Hôpital, 67000 Strasbourg, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Haïkel
authors.forename: M
authors.initials: M
authors.lastname: Freymann
authors.forename: V
authors.initials: V
authors.lastname: Fanti
authors.forename: A
authors.initials: A
authors.lastname: Claisse
authors.forename: F
authors.initials: F
authors.lastname: Poumier
authors.forename: M
authors.initials: M
authors.lastname: Watson
mesh_terms: D000704:Analysis of Variance; D003763:Dental Leakage / Q000175:diagnosis*; D004853:Epoxy Resins / Q000008:administration & dosage / Q000627:therapeutic use; D015902:Gamma Cameras; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D007101:Immersion; D007457:Iodine Radioisotopes; D009113:Muramidase; D019275:Radiopharmaceuticals; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000009:adverse effects / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D018709:Statistics, Nonparametric; D013997:Time Factors; D019227:Tooth Apex / Q000473:pathology
chemical_list: D004853:Epoxy Resins; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D012387:Root Canal Filling Materials; C534916:epoxy resin-based root canal sealer; D006171:Gutta-Percha; D009113:Muramidase