title: The influence of FRCs reinforcement on marginal adaptation of CAD/CAM composite resin endocrowns after simulated fatigue loading.
abstract: To evaluate the marginal adaptation of endodontically treated molars restored with CAD/CAM composite resin endocrowns either with or without reinforcement by fibre reinforced composites (FRCs), used in different configurations. 32 human endodontically treated molars were cut 2 mm over the CEJ. Two interproximal boxes were created with the margins located 1 mm below the CEJ (distal box) and 1 mm over the CEJ (mesial box). All specimens were divided in four groups (n = 8). The pulp chamber was filled with: group 1 (control), hybrid resin composite (G-aenial Posterior, GC); group 2, as group 1 but covered by 3 meshes of E-glass fibres (EverStick NET, Stick Tech); group 3, FRC resin (EverX Posterior, GC); group 4, as group 3 but covered by 3 meshes of E-glass fibres. The crowns of all teeth were restored with CAD/CAM composite resin endocrowns (LAVA Ultimate, 3M). All specimens were thermo-mechanically loaded in a computer-controlled chewing machine (600,000 cycles, 1.6 Hz, 49 N and simultaneously 1500 thermo-cycles, 60 s, 5-55 °C). Marginal analysis before and after the loading was carried out on epoxy replicas by SEM at 200× magnification. For all the groups, the percentage values of perfect marginal adaptation after loading were always significantly lower than before loading (p < 0.05). The marginal adaptation before and after loading was not significantly different between the experimental groups (p > 0.05). Within the limitations of this in vitro study, the use of FRCs to reinforce the pulp chamber of devitalized molars restored with CAD/CAM composite resin restorations did not significantly influenced their marginal quality.
authors: Division of Cariology and Endodontology, School of Dentistry, University of Geneva, 19 Rue, Barthélémy Menn, 1205, Geneva, Switzerland. giovanni.rocca@unige.ch.
authors: Giovanni Tommaso
authors: GT
authors: Rocca
authors: Division of Cariology and Endodontology, School of Dentistry, University of Geneva, 19 Rue, Barthélémy Menn, 1205, Geneva, Switzerland.
authors: Carlo Massimo
authors: CM
authors: Saratti
authors: CRC and Division of Clinical-Epidemiology, Department of Health and Community Medicine, University of Geneva and University Hospitals of Geneva, Geneva, Switzerland.
authors: Antoine
authors: A
authors: Poncet
authors: Department of Dental Materials Science, ACTA, Amsterdam, The Netherlands.
authors: Albert J
authors: AJ
authors: Feilzer
authors: Division of Cariology and Endodontology, School of Dentistry, University of Geneva, 19 Rue, Barthélémy Menn, 1205, Geneva, Switzerland.
authors: Ivo
authors: I
authors: Krejci
mesh_terms: D003188:Composite Resins; D003442:Crowns; D018772:Dental Marginal Adaptation; D003764:Dental Materials; D006801:Humans; D008963:Molar
chemical_list: D003188:Composite Resins; D003764:Dental Materials
keywords: CAD/CAM; Composite; Endocrown; Endodontically treated teeth; FRCs; Marginal adaptation