title: Correlative analysis of cement-dentin interfaces using an interfacial fracture toughness and micro-tensile bond strength approach.
abstract: To determine the interfacial fracture toughness (iFT) and micro-tensile strength (μTBS) of composite cements bonded to dentin.
  
  
  
  Fifty feldspar ceramic blocks (Vita Mark II, Vita Zahnfabrik) were luted onto dentin using two self-adhesive (G-CEM LinkAce, GC; SpeedCEM, Ivoclar Vivadent), two self-etch (Multilink Primer & Multilink Automix, Ivoclar Vivadent; Scotchbond Universal & RelyX Ultimate, 3 M ESPE), and one etch-and-rinse (Excite F DSC & Variolink II, Ivoclar Vivadent) composite cement (n=10). After 48h in 100% relative humidity at 37°C, one half of each tooth was sectioned in sticks with a chevron notch at the cement-dentin interface and tested in a 4-point bending test setup (iFT). The remaining half of the tooth was sectioned in micro-specimens and stressed in tension until failure (μTBS). The mode of failure was determined with a stereomicroscope at 50× magnification. Data were submitted to Weibull analysis and Pearson's correlation (α=0.05).
  
  
  
  At 10% probability of failure, no significant differences could be found using iFT, while the etch-and-rinse composite cement Variolink II presented a significantly higher μTBS at this level. At 63.2% probability of failure, the self-adhesive composite cement G-CEM LinkAce revealed a significantly lower μTBS and iFT, and the self-etch cement Multilink Automix also revealed a significantly lower μTBS than all other cements. The correlation found between iFT and μTBS was moderate and not significant (r2=0.618, p=0.11).
  
  
  
  Overall, the etch-and-rinse and 'universal' self-etch composite cements performed best. The micro-tensile bond strength and interfacial fracture toughness tests did not correlate well.
authors: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Leuven, Belgium; Pontifícia Universidade Católica do Paraná (PUCPR), School of Life Sciences, Graduate Program in Dentistry & Federal University of Paraná, Dental School, Restorative Dentistry Department, Curitiba, PR, Brazil.
authors: Evelise M
authors: EM
authors: Souza
authors: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Leuven, Belgium.
authors: Jan
authors: J
authors: De Munck
authors: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Leuven, Belgium.
authors: Pong
authors: P
authors: Pongprueksa
authors: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Leuven, Belgium.
authors: Annelies
authors: A
authors: Van Ende
authors: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Leuven, Belgium. Electronic address: bart.vanmeerbeek@kuleuven.be.
authors: Bart
authors: B
authors: Van Meerbeek
mesh_terms: D003188:Composite Resins; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin; D008422:Materials Testing; D019279:Resin Cements; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D019279:Resin Cements
keywords: Adhesive luting; Bonding; Composite cement; Dentin; Fracture toughness; Micro-tensile bond strength