Effect of cyclic compressive loading on the bond strength of an adhesive system to dentin after collagen removal.
OBJECTIVE
The objective of this study was to verify the effect of cyclic compressive loading on the shear bond strength of an adhesive system following collagen removal.


METHODS
Sixty bovine teeth were divided into 4 groups based on the adhesive procedure used: groups 1 and 2--etching with 35% phosphoric acid and application of the Single Bond adhesive system; groups 3 and 4--after etching, a 10% sodium hypochlorite solution was applied for 1 min before the application of the adhesive. In all the specimens, a Z100 resin cylinder was built up over the bond area. Groups 2 and 4 were submitted to 500,000 cycles with a load of 100 N.


RESULTS
The mean values for the shear bond test (MPa) were: group 1: 7.37 +/- 1.15; group 2: 5.72 +/- 1.66; group 3: 5.95 +/- 1.21; group 4: 3.66 +/- 1.12. There was no difference between groups 1 and 2 (p > 0.01). Between groups 1 and 3, 2 and 4, and 3 and 4 there was a significant difference (p < 0.01). The majority of the specimens demonstrated an adhesive failure.


CONCLUSIONS
The application of sodium hypochlorite on dentin decreased the values of shear bond strength, as did the load cycling in the group treated with sodium hypochlorite.
dos Santos
Paulo Henrique
PH
Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University-UNESP, Brazil.
Sinhoreti
Mário Alexandre Coelho
MA
Consani
Simonides
S
Sobrinho
Lourenço Correr
LC
Adabo
Gelson Luis
GL
Vaz
Luis Geraldo
LG
D000134:Acid Etching, Dental; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry; D033081:Shear Strength; D012822:Silicon Dioxide / Q000737:chemistry; D012973:Sodium Hypochlorite / Q000737:chemistry; D013314:Stress, Mechanical; D015040:Zirconium / Q000737:chemistry
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D016877:Oxidants; D010756:Phosphoric Acids; C083568:Z100 composite resin; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D003094:Collagen; D015040:Zirconium; D012973:Sodium Hypochlorite