Influence of pH of different adhesive systems on the polymerization of a chemically cured composite resin.
The purpose of this study was to investigate the effect of pH of different adhesive systems on the polymerization of a chemically cured composite resin (Adaptic--AD), by means of tensile bond strength testing. The adhesive systems tested were: ARM, Prime & Bond 2.1 (PB), Scotchbond Multi Purpose (SMP) and Single Bond (SB). Bond strength at the resin/adhesive system/resin interface was assessed. Five groups (n=5) were formed, according to following configuration: G1: AD/ARM/AD; G2: AD/PB/AD; G3: AD/SMP/AD; G4: AD/SB/AD; G5: AD/AD (no adhesive). A two-mold stainless steel matrix with a cone-shaped opening (1-mm-thick; 4 mm in diameter) was used to obtain resin discs. AD resin was inserted into the first mold, left-self curing and an adhesive layer was applied onto resin surface and light-cured. The second mold was assembled over the first and was filled with the resin. After 10 min, this setting was loaded in tension in a universal testing machine running at a crosshead speed of 0.5 mm/min. Data were submitted to one-way ANOVA and Tukey's test (p<0.05). Bond strength means (kgf) were: G1: 15.23 +/- 4.1; G2: 0.00 +/- 0.0; G3: 16.96 +/- 2.4; G4: 10.08 +/- 2.7; G5: 15.44 +/- 0.9. There were statistically significant differences (p<0.05) between G2-G1; G2-G3; G2-G4; G4-G1; G4-G3. The systems with the lowest pHs (PB and SB) yielded the lowest bond strength. The findings of this in vitro study demostrates that the pH of adhesive systems influences the polymerization and bond strength of chemically cured resin materials. The low pH simplified adhesive systems showed distinct degrees of incompatibility with the chemically cured resin, when compared to the conventional adhesive systems.
Department of Operative Dentistry, Endodontics and Dental Materials, Faculty of Dentistry of Bauru, University of São Paulo, Brazil. ebfranco@fob.usp.br
Eduardo Batista
EB
Franco
Lawrence Gonzaga
LG
Lopes
Paulo Henrique Perlatti
PH
D'Alpino
José Carlos
JC
Pereira
D000096:Acetone / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013718:Tensile Strength
C090889:ARM resin; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D011108:Polymers; D011109:Polymethacrylic Acids; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C444444:prime and bond 2.1; C115612:single bond; D000096:Acetone; D017438:Bisphenol A-Glycidyl Methacrylate; C031112:Adaptic Bonding Agent