title: Use of dental adhesives as modeler liquid of resin composites.
abstract: OBJECTIVE
  Resin adhesives (RA) have been applied between resin composite (RC) increments, but there is no consensus on the impact of this technique on the properties of the final restoration. This study evaluated the effect of the presence of RA between RC layers on physical properties, translucency and long-term color stability of the restorative material.
  
  
  METHODS
  Scotchbond™ Multi-Purpose (bond, 3M ESPE) and Adper™ Single Bond 2 (3M ESPE) were used as RA, and Filtek™ Z350 (3M ESPE) as RC. Specimens containing RA were prepared by applying 3 layers of the adhesive between 4 increments of RC; adhesive-free specimens were also used (control). Tests of water sorption and solubility, mechanical performance (microtensile cohesive strength, flexural strength, and flexural modulus, after immediate and long-term water storage), and translucency and color stability (after immediate and 1, 7, 90, and 180 days of water or wine storage) were performed. Scanning electron microscopy (SEM) images were also taken from the fractured specimens (flexural strength test). Data were analyzed using ANOVA and Tukey test (p<0.05).
  
  
  RESULTS
  Scotchbond (SBMP) showed lower water sorption and solubility than the control (p<0.001), and an overall similar (p≥0.198, immediate tests) or higher (p≤0.019, long-term tests) mechanical performance. SBMP exhibited a rougher cross-sectional surface compared to the other groups. Translucency remained unaltered after 180 days of storage (p≥0.313), except for single bond that had increased translucency with wine storage (p<0.045). After 180 days, all groups changed color (p≤0.002), although more intensively when immersed in wine.
  
  
  CONCLUSIONS
  The presence of RA within RC increments increased the physical stability of the material, being this effect more evident by using the hydrophobic unfilled adhesive resin (SBMP). This study is the first to show positive results from the use of resin adhesives as modeler liquid of resin composite, which is common in clinical practice.
authors: Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS 96015-560, Brazil. Electronic address: eliseumunchow@hotmail.com.
authors: Eliseu Aldrighi
authors: EA
authors: Münchow
authors: Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS 96015-560, Brazil.
authors: José Augusto
authors: JA
authors: Sedrez-Porto
authors: Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS 96015-560, Brazil.
authors: Evandro
authors: E
authors: Piva
authors: Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS 96015-560, Brazil.
authors: Tatiana
authors: T
authors: Pereira-Cenci
authors: Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, RS 96015-560, Brazil.
authors: Maximiliano Sergio
authors: MS
authors: Cenci
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry; D017220:Dentin-Bonding Agents / Q000737:chemistry; D055119:Elastic Modulus; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C533204:filtek Z350; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C041330:Scotchbond
keywords: Color stability; Flexural modulus; Flexural strength; Translucency; Water sorption and solubility