Effect of acid etching and desensitization on the bonding strength of dentin and zirconia

Abstract:

Objective：To evaluate the effects of acid etching and two kinds desensitizing agents on zirconia and dentin in order to pro－vide references for clinical treatment. Methods：Fifty molars（the third molar） without caries were collected and the crowns of the mo－lars were removed to expose the dentin. All samples were divided into control group A and experimental groups B，B1，C，C1（n=10）. All 50 molars were immersed into 1∶3 fetal bovine serum solution and were taken out 1 d after. No treatment was made in group A；molars in groups B and B1 were coated by Gluma desensitizer；molars of groups C，and C1 were treated by water. Before bonding，mo－lars in groups B1 and C1 were treated by phosphoric acid for 15 seconds while no treatment was made in other groups. The dentin of specimens were bonded with zirconia with the same size at the bottom and the shear strength was determined. The results were ana－lyzed by software of SPSS 17.0. Results：The bonding strength：A group（9.626±0.318） MPa，B group（12.577±0.374） MPa，B1 group（15.650±0.344） MPa，C group（9.530±0.391） MPa，C1 group（12.740±0.310） MPa. There were statistical differences between groups（P<0.05） except comparison between group A and group C（P >0.05） and between group B and group C1（P >0.05）. Conclusion：Gluma desensitizer can enhance the bonding strength of Rely XTM Unicem on dentin. Proper phosphoric acid etching of dentin treat－ed by water laser or Gluma desensitization can enhance the bonding strength of Rely XTM Unicem on dentin.