title: Influence of different root canal-filling materials on the mechanical properties of root canal dentin.
abstract: The aims of this study were to compare Resilon (Resilon Research LLC, Madison, CT) in conjunction with either a bonding (Epiphany; Pentron Clinical Technologies, Wallingford, CT) or a nonbonding endodontic sealer (Pulp Canal Sealer; Kerr Corporation, Orange, CA) to EndoRez (Ultradent Products Inc, South Jordan, UT) and gutta-percha with regards to the physical properties and flexural stress in standardized dentin cylinders and the flexural stress of Resilon and gutta-percha. The external surface of 50 maxillary central incisors was reduced by means of mechanical milling to obtain dentin cylinders with an external diameter of 3 mm and minimum length of 12 mm. Root canals were prepared to obtain a standardized cylindrical preparation of 1.3 mm in diameter at the center of the root. The cylinders were randomly divided into five groups (n = 10): group 1: obturation with gutta-percha and Pulp Canal Sealer; group 2: obturation with Resilon, Epiphany primer, and Epiphany; group 3: obturation with Resilon and Pulp Canal Sealer; group 4: obturation with EndoRez methacrylate-based endodontic sealer; and group 5: dentin cylinders were not obturated. Ten gutta-percha (group 6) and Resilon (group 7) pellets for the Obtura gun were also tested. A three-point bending test was used to measure the maximum load values of specimens from groups 1 to 5 and the flexural strength and flexural modulus values for specimens from groups 6 and 7. Statistical analysis was performed to determine significance differences (p < 0.05). An analysis of variance test showed no significant difference among groups 1 to 5 (p = 0.697; F = 0.60). An independent sample t test showed statistically significant differences between groups 6 and 7 in flexural strength (p = 0.000) and flexural modulus (p = 0.000). Within the limits of this study, it may be concluded that the currently available endodontic-filling materials and their recommended adhesive procedures are not able to influence the mechanical properties of root canal dentin and that the flexural properties of Resilon and gutta-percha are too low to reinforce roots.
authors.affiliation: Department of Endodontics, Catholic University of Sacred Heart, Rome, Italy.
authors.forename: Nicola M
authors.initials: NM
authors.lastname: Grande
authors.forename: Gianluca
authors.initials: G
authors.lastname: Plotino
authors.forename: Luca
authors.initials: L
authors.lastname: Lavorgna
authors.forename: Pietro
authors.initials: P
authors.lastname: Ioppolo
authors.forename: Rossella
authors.initials: R
authors.lastname: Bedini
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: Pameijer
authors.forename: Francesco
authors.initials: F
authors.lastname: Somma
mesh_terms: D000704:Analysis of Variance; D003786:Dental Pulp Cavity / Q000737:chemistry / Q000187:drug effects*; D003799:Dental Stress Analysis / Q000379:methods*; D003804:Dentin / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D018583:Pliability / Q000187:drug effects; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000494:pharmacology*