title: The effect of insertion rates on fill length and adaptation of a thermoplasticized gutta-percha technique.
abstract: The purpose of this in vivo study was to determine the effect of the insertion rate of a thermoplasticized gutta-percha obturation technique (Thermafil Plus) on the quality of the root canal obturation. A calibrated practitioner obturated the tooth in each of three groups with insertion rates of 18, 6, and 3 mm/s, respectively. The quality of the obturation was assessed by measuring the length of fill and the replication of induced canal irregularities, consisting of dimples and grooves. All measurements were made on a single tooth, with a working length of 18 mm from the canal orifice, embedded in a split mold, with 20 measurements for each insertion rate. Measurements were made under a low-power microscope, with the images recorded on videotape. The length of fill decreased with decreasing the insertion rate, from a mean overextension of +0.88 mm (SD 1.12 mm) for the 18 mm/s rate to a mean underfill of -0.13 mm (SD 1.03 mm) for the 3 mm/s rate. A trend of decreasing fill with decreasing insertion rate was observed, with the difference between the insertion rates of 18 mm/s and 3 mm/s being statistically significant at p < 0.05 using a single comparison test. Replication of dimples decreased with decreasing the insertion rate from a mean reproduction of 99% for the 18 mm/s rate to a mean reproduction of 90% for the 3 mm/s rate. The replication of grooves also decreased with decreasing the insertion rate from a mean reproduction of 100% for the 18 mm/s rate to a mean reproduction of 88% for the 12 mm/s rate. Statistical analysis of the data for both the dimples and the grooves using a paired comparison post hoc Scheffe test found these differences are significant at p < 0.05.
authors.affiliation: Department of Biologic and Diagnostic Sciences, College of Dentistry, University of Tennessee Health Science Center, Memphis 38163, USA.
authors.forename: Marc E
authors.initials: ME
authors.lastname: Levitan
authors.forename: Van T
authors.initials: VT
authors.lastname: Himel
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Luckey
mesh_terms: D006171:Gutta-Percha; D006801:Humans; D007180:Incisor; D012389:Root Canal Obturation / Q000379:methods*; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D006171:Gutta-Percha