Comparison Of Tensile Strength Of Three Kinds Of Bonding Systems On Cast Porcelain Veneers

Objective The bonding ability of bonding system is usually measured by bond strength,and the size of bond strength is usually reacted by the two indicators of tensile strength and shear strength^[1].As to the shear strength of the three kinds of materials,Qi Feng^[2]results have showed that the shear strength of Variolink adhesive system is relatively large.The experiment is concentrated on another measure of bond strength such as tensile strength of the three kinds of adhesive system,providing a theoretical basis for the clinical choice of relatively comprehensive face binder.Methods First of all,we choose maxillary middle and lateral incisors extracted from periodontitis.?Stored at 4?saline solution.?,using a standard needle to prepare the depth of about 0.3-0.6mm to form 2*2 square millimetre of the plane on the middle of the lip enamel.Then,using 400#,600#,800#,and 1000#sand paper grind the prepared tooth bonding surface to form the standard plane.Then we use the PanaviaF adhesive system,Variolink adhesive system and Choice adhesive system to bond the 24 cast porcelain veneer specimens divided into three groups whose diameter?d?is 2mm,and height is 4mm to the teeth respectively.Then,we put the bonded specimens in the water of 37?for 24h.After the above operations,we put the specimens into the cold and heat circulating instrument to circulate 3000 times.At last,we test the tensile strength of each group.Results The tensile strength of Variolink bonding system?group A?is the largest,PanaviaF bonding system?group B?is the second,and Choice bonding system?group C?is the smallest.We contrast group A,group B and group C mutually and sanalyze tatistically,and the t0.05 of each group is 2.228,and the P value was less than 0.001,that is,P<0.05,so the difference was statistically significant.Conclusion Through this experimental study,the tensile strength of the three kinds of adhesives,Variolink,PanaviaF and Choice,is decreasing in turn.In clinical patch repairing,it is suggested to use a relatively simple self etching binder PanaviaF.