title: Marginal adaptation of three Class II composite restorative techniques in vitro.
abstract: The purpose of this study was to evaluate the marginal integrity of three different Class II restorative techniques in vitro. Mesioocclusal (MO) preparations (no bevels) 4 mm x 3 mm x 2 mm were made on 15 freshly extracted human premolars mounted in cold cure acrylic. The preparations were randomly divided into three groups of five: Group I: Direct technique Group II: Indirect single-visit technique Group III: Indirect laboratory technique Group II cavity preparations were duplicated using alginate impression material (Jeltrate Plus, DENTSPLY Caulk) and a polyvinylsiloxane die material (Mach II, Parkell). Group III preparations were duplicated using polyether impression material (Impregum, ESPE) and type IV die stone (G.C. America Inc., Fujirock). All restorations were fabricated with Tetric Ceram (Vivadent-Ivoclar) microhybrid composite according to manufacturers' recommendations. The inlays were cemented using a dual-cure bonding system (All Bond II, Bisco) and a resin-based cement (Variolink, Vivadent-Ivoclar) and polished according to manufacturers' recommendations. The specimens were examined under an environmental scanning electron microscope (Electroscan). None of the samples was sectioned before examination. The width of the largest gap at the gingival margin, between the restorations and preparations, was recorded in microns. The average gap width for each group was the following: Group I: 63.4 +/- 9.06 microns Group II: 73.54 +/- 13.9 microns Group III: 89.58 +/- 18.5 microns Statistical analysis (one-way ANOVA) revealed that a significant difference exists among the three groups (p = 0.03). Students t-tests revealed a statistical significant difference between Groups I and III (p < 0.02), but did not prove significant between Groups I and II (p > 0.10) and Groups II and III (p > 0.05).
authors.affiliation: Tufts University School of Dental Medicine, USA.
authors.forename: A
authors.initials: A
authors.lastname: Papthanasiou
authors.forename: D
authors.initials: D
authors.lastname: Bardwell
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods; D006801:Humans; D007284:Inlays / Q000379:methods; D011897:Random Allocation
chemical_list: D003188:Composite Resins; C121818:Tetric ceram