Machinable Non-Segmented Implant-Supported Restorations: Impact of Material Types on The Torque Maintenance

Objectives:
The aim of this study was toevaluate the torque maintenance of zirconia,glass-ceramic and PEEK non-segmented implant-supported restorations after artificial aging.
Materials and Methods:
Thirty implant fixtures and their titanium bases were divided into three groups (n=10) according to the type of abutment material into:Group Z: non-segmented zirconia abutments.Group G: non-segmented glass-ceramic abutments.Group P: non-segmented PEEK abutments.
All implants were installed in the epoxy casts and the titanium bases were anchored. The non-segmented abutments were fabricated from zirconia, glass-ceramic and PEEK materials. The milled abutments were luted to the titanium base with dual cure resin cement. The abutments were attached to their corresponding implants to the recommended torque. All specimens were subjected to artificial aging (7000 cycles). The digital torque meter was used to determine the torque loss. Data was analyzed by using ANOVA and Tukey post hoc.
Results:
        There was no significant difference in torque maintenance between (zirconia, IPS e.max CAD and PEEK) but in each group, there was significant difference.
Conclusions:
Under the conditions of this study:
1.Thermal aging affected the torque maintenance of all tested non-segmented abutments.
2.The abutment material (zirconia, IPS e.max CAD and PEEK) didn't affect the torque maintenance of non-segmented abutments.