Effect Of Different Surface Pretreatments On The Shear Bond Strength Of PEEK To PMMA

Objective:This study was to compare the shear bond strength between PEEK and PMMA and to find out the influence of different surface treatments by using physical（sandblast,laser）and chemical（different primers）methods.Methods:（1）Physical methods:68 specimens randomly divided into 4 groups,17specimens in each group（16 specimens and 1 used for surface morphology）respectively:Co（Control group）,SA_0.05（0.05 MPa sandblast group）,SA_0.35（0.35 MPa sandblast group）,LA（laser group）;Each group randomly pick one specimen to observing surface morphology using SEM;The surface roughness is compared using the surface roughness measurement.Specimen was tested at the central area at three locations and averaged the results;The specimens were bonded with PMMA,half of each group stored in distilled water and other specimens put into the hot and cold circulation box,hot and cold cycle 5000 times.And then testing sample shear strength by universal test machine.（2）Chemical methods:64 specimens randomly divided into 4groups,16 specimens in each group,respectively:CO（control group）,ZP（Z-Prime plus group）,UN（Universal group）,VL（Visio.link group）;The specimens were bonded with PMMA,half of each group stored in distilled water and other specimens put into the hot and cold circulation box,hot and cold cycle 5000 times.And then testing sample shear strength by universal test machine.（3）Single factor analysis of variance,double factor analysis of variance were carried out by SPSS19.0 software.Results:（1）Physical methods:Surface morphology of specimens using SEM shows that the control group showed a basically regular and flat appearance.The surface of the laser group was slightly rougher than that of the control group,with some bulges.The sandblast group show irregular and some grooves appearance,the grooves were deeper when pressure was 0.35 MPa;Surface roughness:Co group<LA group<SA_0.05 group<SA_0.35 group.The surface roughness of PEEK after treatment was significantly different between groups（P<0.05）;Shear bond strength:Co group<LA group<SA_0.05group<SA_0.35 group.After cycle,the shear strength compared with 24 h of each group decreased significantly after cycling except SA_0.35 group（P>0.05）.（2）Chemical methods:24 h shear bond strength:CO（control group）<UN（Universal group）<ZP（Z-Prime plus group）<VL（Visio.link group）.Compared with the CO（control group）,the shear bond strength of the groups using primers were significantly increased;The shear bond strength after cycle:ZP（Z-Prime plus group）<CO（control group）<UN（Universal group）<VL（Visio.link group）.There was no significant difference in shear bond strength between CO and ZP（P>0.05）;The shear strength compared 24h to after cycle,each group was decrease.There was no statistical difference between CO and UN,and there was a statistically significant difference between ZP and VL（P<0.05）.Conclusion:（1）Nd:YAG laser can change the surface topography of PEEK.（2）Sandblast can improve the shear bond strength of PEEK.Raising the pressure properly is beneficial to the stability.（3）Visio.link shows the highest shear bond strength;Single bond Universal shows good stability.It is also an optional agent.