title: In vitro evaluation of adhesive characteristics of 4-META/MMA-TBB resin with organic filler.
abstract: OBJECTIVE
  A commercial restorative material, BondfillSB (BF), is a modification of 4-META/MMA-TBB resin cement. BF uses a self-etching primer and added pre-polymerized organic fillers. We compared BF with another self-etching system, EasyBond (EB), in shear bond strength, bonded interface characteristics to human dentin and contraction gap when used in bulk-filling.
  
  
  METHODS
  Shear bond strength of BF and EB + Z100 (Z), bonded by different experience-level operators, was evaluated. Bonded interfaces were characterized by SEM, AFM, and AFM based nano-indentation. Contraction gaps (CG) at 0h and 24h after polymerization were evaluated for BF or EB bulk filled class I cavities. To meet the clinical recommendation, BF's powder was replaced by experimental radioopaque powder (BFO) for the CG study. EB was used with Z (EBZ) or with a resin marketed for bulk-fill base (SureFil-SDR-flow (EBSF)).
  
  
  RESULTS
  Shear bond strengths (Mean ± Standard Deviation (S.D.)) of BF (37.4 ± 2.6 MPa; n=36) were higher and less variable than EBZ (18.2 ± 7.6 MPa; n=36) (p<0.0001, One-way ANOVA). Weibull characteristic strength (η) differed significantly between materials (p<0.0001) but not between operators (p=0.90). EBZ often had non-uniform interfaces and a wider band of reduced elastic modulus (E) of greater than 20 μm across the interface. BF had uniform interfaces and a smaller width of affected dentin under the interface (∼1 μm). There was a difference in dentin-E between EBZ and BF up to 9 μm from the interface (mixed-effects model; P=0.03). A stratified linear regression model used for CG. EBSF and BFO showed significantly smaller CG than EBZ at time 0. None of three combinations showed any significant change between 0h-CG and 24h-CG.
  
  
  CONCLUSIONS
  BF possessed bonding characteristics required to serve as a restorative.
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA. Electronic address: kuniko.saeki@ucsf.edu.
authors.forename: Kuniko
authors.initials: K
authors.lastname: Saeki
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Chin
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA.
authors.forename: Grace T
authors.initials: GT
authors.lastname: Nonomura
authors.affiliation: Department of Epidemiology & Biostatistics, University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158-2549, USA.
authors.forename: Joan F
authors.initials: JF
authors.lastname: Hilton
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA.
authors.forename: Yung-Ching
authors.initials: YC
authors.lastname: Chien
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA.
authors.forename: Sally J
authors.initials: SJ
authors.lastname: Marshall
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, 707 Parnassus Avenue, San Francisco, CA, 94143-0758, USA.
authors.forename: Grayson W
authors.initials: GW
authors.lastname: Marshall
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D003188:Composite Resins; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D066298:In Vitro Techniques; D008689:Methacrylates / Q000737:chemistry*; D008768:Methylmethacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008963:Molar; D019279:Resin Cements / Q000737:chemistry*; D055116:Self-Curing of Dental Resins; D033081:Shear Strength
chemical_list: D001896:Boron Compounds; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C448319:ESPE bonding system; D008689:Methacrylates; D008768:Methylmethacrylates; D019279:Resin Cements; C553871:Surefil SDR Flow; C584661:easy bond; C476987:methylmethacrylate-tributylborane resin; C034139:4-methacryloxyethyltrimellitic acid anhydride; C049495:Super-bond
keywords: AFM; Contraction gap; Dentin; Nanomechanical properties; Self etching; Shear bond strength