title: The effect of additional enamel etching and a flowable composite to the interfacial integrity of Class II adhesive composite restorations.
abstract: This in vitro study evaluated the interfacial integrity of Class II resin composite restorations. The influence of a flowable composite and additional enamel etching was also evaluated. Deep, saucer-shaped Class II cavities were prepared in the mesial and distal proximal surfaces of 25 extracted human molars and assigned to five treatment groups. The gingival margins were extended to approximately 1 mm above the CEJ in 40 cavities and below the CEJ in 10 cavities. The prepared cavities were then restored with a self-etching primer system (Clearfil Liner Bond II) and a hybrid resin composite (Clearfil AP-X), with and without a flowable composite (Protect Liner F) and additional enamel etching with 37% phosphoric acid gel (K-etchant). After finishing, polishing and thermocycling (4 and 60 degrees C, x300), the samples were longitudinally sectioned through the restorations and resin-tooth interfaces were observed directly under a laser scanning microscope. Statistical analysis indicated that the use of a flowable composite produced significantly more (p = 0.04) gap-free resin-dentin interfaces than teeth restored without the flowable composite. However, both flowable composite and enamel etching could not prevent gap formation at enamel-resin interfaces and crack formation on enamel walls.
authors.affiliation: Selçuk University, Dental Faculty, Department of Operative Dentistry, 42079, Campus, Konya, Türkiye.
authors.forename: S
authors.initials: S
authors.lastname: Belli
authors.forename: S
authors.initials: S
authors.lastname: Inokoshi
authors.forename: F
authors.initials: F
authors.lastname: Ozer
authors.forename: P N
authors.initials: PN
authors.lastname: Pereira
authors.forename: M
authors.initials: M
authors.lastname: Ogata
authors.forename: J
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins / Q000737:chemistry*; D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation / Q000145:classification; D003743:Dental Enamel / Q000648:ultrastructure*; D018772:Dental Marginal Adaptation; D003775:Dental Polishing; D003793:Dental Restoration, Permanent / Q000145:classification*; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008963:Molar; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013816:Thermodynamics; D019237:Tooth Cervix / Q000648:ultrastructure; D014783:Viscosity
chemical_list: C112828:Clearfil AP-X; C112274:Clearfil Liner Bond 2; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D010756:Phosphoric Acids; C409388:Protect Liner F; D019279:Resin Cements; C111840:flowable hybrid composite