[Comparison of the shear bond strength by using nano silica sol to zirconia basement and veneer porcelain].

PURPOSE: To investigate the feasibility of using sol gel technique to produce thin layer nano silicon dioxide on zirconia ceramic surface and the effect of improving shear bond strength between zirconia and veneer porcelain. METHODS: The presintered zirconia specimen was cut into a rectangle block piece (15 mmx10 mmx2.5 mm), a total of 40 pieces were obtained and divided into 4 groups, each group had 10 pieces. Four different treatments were used in each group respectively. Pieces in group A (control group) were only sintered at 1450 degrees C to crystallization; pieces in group B underwent 30% nano silica sol infiltration first and then were sintered at 1450 degrees C to crystallization; piece in group C underwent crystallization first at 1450 degrees C, then 30% nano silica sol infiltration and were sintered at 1450 degrees C again; pieces in group D was coated by nano silica sol and then sintered at 1450 degrees C to crystallization; ten rectangle block pieces (12 mmx8 mmx2 mm) in group E were made. Cylinder veneers 5 mm in diameter and 4 mm in height were produced in each group and the shear bond strength was tested. Data were statistically analyzed by SPSS 19.0 software package. RESULTS: The shear bond strength of the 5 group specimens were: (28.12+/-2.95) MPa in group A, (31.09+/-3.94) MPa in group B, (25.60+/-2.45) MPa in group C, (31.75+/-4.90) MPa in group D, (28.67+/-3.95) MPa in group E, respectively. Significant differences existed between the 5 groups, and group C had significant difference compared with group B and D. CONCLUSIONS：1 in circle Use of nano silicon sol gel on presintered zirconia surface to make thin layer of nano silicon dioxide can improve the shear bond strength between zirconia and veneer; 2 in circleUsing nano silicon sol gel on crystallization zirconia surface to make thin layer of nano silicon dioxide will decrease the shear bond strength between zirconia and veneer; 3 in circle Zirconia veneer bilayer ceramic has the same shear bond strength with porcelain fused to Ni Cr alloy; 4 in circleUse of sol gel technique to produce thin layer nano silicon dioxide on zirconia ceramic surface is feasible and can improve shear bond strength between zirconia and veneer porcelain.