title: Microleakage in overflared root canals restored with different fiber reinforced dowels.
abstract: This study evaluated microleakage in overflared root canals restored with four different types of adhesively-luted fiber-reinforced dowels: DT Light Post (LP), Glassix (GL), Ribbond (RB) and StickTech Post (ST). Forty non-carious, single-rooted mandibular human premolars with straight root canals were prepared using a step-back technique and obturated with gutta-percha using lateral condensation. The restored roots were randomly divided into four groups (n=10). The root canals were overprepared, creating an overflared dowel space, and each dowel was adhesively luted using a total-etched adhesive (Single Bond) and dual-polymerizing luting agent (RelyX ARC). All specimens were thermal cycled 1000 times between 5 degrees C and 55 degrees C and stored in 2% methylene-blue solution for one week. The teeth were cut horizontally into three consecutive sections: apical (A), middle (M) and coronal (C). Each section was digitally photographed from the occlusal direction under a stereomicroscope. The images were transferred to a PC and stored in TIFF format. For each image, dye penetration was estimated as the ratio of methylene-blue-infiltrated surface divided by total dentin surfaces. The data were compared and statistically analyzed using the Kruskal-Wallis test (p<.05). The Mann-Whitney U test was used to compute multiple pairwise comparisons to determine differences between the experimental groups (p=.083). Dentin-luting agent fiber-reinforced dowel (FRD) interfaces were evaluated under a scanning electron microscope. Scanning electron microscopy (SEM) showed detachment of the luting resin from the dentin surface in varying degrees in all specimens evaluated. All groups showed considerable leakage at the sections evaluated. Significant differences were demonstrated between LP-RB for the apical and middle sections and between GL-RB, LP-RB and ST-RB for the coronal sections (p<.0083). Among the FRDs evaluated, the individually shaped polyethylene-reinforced dowel (Ribbond) showed the least overall leakage.
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Dentistry, Department of Prosthodontics, Baskent University, Ankara, Turkey. selim@baskent.edu.tr
authors.forename: Selim
authors.initials: S
authors.lastname: Erkut
authors.forename: Kamran
authors.initials: K
authors.lastname: Gulsahi
authors.forename: Alper
authors.initials: A
authors.lastname: Caglar
authors.forename: Pervin
authors.initials: P
authors.lastname: Imirzalioglu
authors.forename: Vistasp M
authors.initials: VM
authors.lastname: Karbhari
authors.forename: Ilknur
authors.initials: I
authors.lastname: Ozmen
mesh_terms: D001641:Bicuspid; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins / Q000737:chemistry; D003763:Dental Leakage / Q000209:etiology*; D017220:Dentin-Bonding Agents; D005898:Glass; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols; D011095:Polyethylenes; D011109:Polymethacrylic Acids; D011176:Post and Core Technique; D011791:Quartz; D019279:Resin Cements; D018915:Root Canal Preparation / Q000009:adverse effects*; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D011095:Polyethylenes; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; C009753:fiberglass; C115612:single bond; D011791:Quartz; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate