IADR Abstract Archives
Adhesion Strength Testing in Dentistry – an Improved Approach
Objectives: Background: Generally, the bonding of one material to another is important for function, and especially with so-called ‘adhesive dentistry’. A reliable test with good discriminatory power that mimics the clinical failure mode has not emerged.
Objective: Develop and validate a test protocol based on 4-point bending that may be used to examine the bonding of various dental materials to a range of substrates. The bonding of an RBC to dentine is taken as an example.
Methods: Slices of dentine (2.0 × 5.0 × 2.0 mm3), from extracted molars were prepared using a diamond saw under running water. Pairs of RBC bars (24.0 × 5.0 × 2.0 mm3) (Z250) were bonded symmetrically either side of a dentine slice using all combinations of the following treatments: E: acid-etched (Scotchbond Universal Etchant), P: primer (Adper Scotchbond Multipurpose Adhesive); A: adhesive (Adper Scotchbond Multipurpose Primer) (all 3M) as well as NT: no treatment. At 24 h (100% RH, 37 °C), test pieces were subject to 4-point bending at 23 °C, cross-head speed 0.5 mm/min, until fracture. 3-way Analysis of Variance on log(bend strength) was applied. Scanning electron microscopy (SEM) was used to examine fracture surfaces and identify failure origins.
Results: Fracture strengths in MPa: NT: 1.38 ± 0.56; P: 9.82 ± 0.89; A: 5.12 ± 0.73; E: 9.39 ± 1.78; E+P: 21.03 ± 2.63; E+A: 12.80 ± 1.53; P+A: 17.16 ± 3.03; E+P+A: 20.84 ± 3.93. The main effects of the treatments (p < 10-12) were not additive, there being significant two-way (p < 10-5) and three-way (p = 0.037) interactions. There was no significant difference between E+P+A and E+P (p = 0.86).
Conclusions: With good reproducibility, high discriminatory power, economy with regard to substrates, and a straightforward robust process, the method is adaptable to many systems.
Objective: Develop and validate a test protocol based on 4-point bending that may be used to examine the bonding of various dental materials to a range of substrates. The bonding of an RBC to dentine is taken as an example.
Methods: Slices of dentine (2.0 × 5.0 × 2.0 mm3), from extracted molars were prepared using a diamond saw under running water. Pairs of RBC bars (24.0 × 5.0 × 2.0 mm3) (Z250) were bonded symmetrically either side of a dentine slice using all combinations of the following treatments: E: acid-etched (Scotchbond Universal Etchant), P: primer (Adper Scotchbond Multipurpose Adhesive); A: adhesive (Adper Scotchbond Multipurpose Primer) (all 3M) as well as NT: no treatment. At 24 h (100% RH, 37 °C), test pieces were subject to 4-point bending at 23 °C, cross-head speed 0.5 mm/min, until fracture. 3-way Analysis of Variance on log(bend strength) was applied. Scanning electron microscopy (SEM) was used to examine fracture surfaces and identify failure origins.
Results: Fracture strengths in MPa: NT: 1.38 ± 0.56; P: 9.82 ± 0.89; A: 5.12 ± 0.73; E: 9.39 ± 1.78; E+P: 21.03 ± 2.63; E+A: 12.80 ± 1.53; P+A: 17.16 ± 3.03; E+P+A: 20.84 ± 3.93. The main effects of the treatments (p < 10-12) were not additive, there being significant two-way (p < 10-5) and three-way (p = 0.037) interactions. There was no significant difference between E+P+A and E+P (p = 0.86).
Conclusions: With good reproducibility, high discriminatory power, economy with regard to substrates, and a straightforward robust process, the method is adaptable to many systems.