Comparative Evaluation Of BioHPP And Titanium As A Framework Veneered Composite Material For Implant-supported FDPs

Objective: BioHPP is a bio-high performance polymer material,which is a modified version of polyetheretherketone(PEEK).The purpose of this in vitro study was to compare bond strength with a veneering composite resin between modified PEEK(BioHHP)and titanium alloy,and to compare the marginal fit and fracture resistance of implant-supported fixed dental prostheses(FDPs)fabricated with computer-aided design and computer-aided manufacturing(CAD/CAM)frameworks veneered with composite resin.Methods: The study included three parts: In experiment 1,the same cylindrical chassis(d=25mm,h=4mm)(n=20/group)was made from the discs by CAD/CAM.A composite resin(d=14mm,h=2mm)was bonded to 2 framework materials(n=20/group):Titanium(Ti)and BioHPP(Bi).Shear bond strength(SBS)was determined after 24-hour wet storage and thermocycling and mastication simulation treatment.In experiment 2,twenty 3-unit CAD/CAM BioHPP and titanium frameworks were fabricated(n=10/group).The marginal fit between frameworks and abutments was evaluated by scanning electron microscopy using the single-screw test.The distal,middle and mesial buccal interfaces were measured.The third experiment was to test the fracture resistance of FDPs veneered with the composite resin and compare the failure modes of the two groups of specimens after thermal cycling and mastication simulation.The data were analyzed by SPSS 19.0 software.The independent sample t test was used to evaluate differences(?=0.05).Results: 1.In the first experiment,the shear bond strength(31.1±3.5)MPa of BioHPP(Bi)group was significantly higher than that of Ti(20.5±1.8)MPa(P<0.05).2.In experiment 2,the mean marginal gap width was(19±4)?m in group Bi and(16±6)?m in group Ti.Statistical tests showed no significant differences(P>0.05).3.In experiment3,after loading,veneering chipping was observed at a load of(1960±233)N in group Ti.Although the BioHPP frameworks fractured at(1518±134)N,no chipping occurred.Conclusion: The bond strength of BioHPP with the composite resin was greater than titanium alloy.CAD/CAM BioHPP frameworks exhibited good marginal fit andfracture resistance.BioHPP seems to be a suitable alternative to metal as a framework to be veneered with composite resin,which could meet the clinical need.