Evaluation of machining tolerance and vertical microgaps of biohpp peek and cadcam milled zirconia abutments over titanium implants

Evaluation of machining tolerance and vertical microgaps of biohpp peek and cadcam milled zirconia abutments over titanium implants

Purpose: To compare the machining tolerance and vertical microgap at two different implant-abutment interfaces. Materials and Methods: Twenty-four titanium implants (Bioline, Israel) with an internal hex were divided into two groups, A (Bio-HPP PEEK abutment, Norris, Israel) and B (CADCAM milled zirconia abutments, Dentgallop, USA), and embedded in clear auto polymerizing resin and tightened to a torque of 35Ncm. The machining tolerance was then evaluated using a coordinate measuring machine (GMT Grano7-10-6, India) and vertical microgap at the implant abutment interface using a scanning electron microscope (JEOL 6000 PLUS, Japan) at six regions (front right, front centre, front back, back right, back centre, and back left). Data obtained were tabulated and statistically analyzed using an independent t-test. Results: Mean machining tolerances at the implant-abutment interface of the group A and B samples were 126.75 μm and 536.33 μm, respectively, on the x-axis. An independent t-test showed a significant difference in the machining tolerance and vertical microgaps between the two groups in four regions. The microgaps values of four zones of the Group A samples were significantly less than the Group B samples. The front centre zones of the Group A samples had the least vertical microgap compared to the six zones of the Group B samples. The front right zones of the Group A samples had the highest vertical microgaps that were still less than the vertical microgaps of the Group A samples in all six zones (P<0.05). Conclusions: Bio-HPP PEEK abutment-titanium implant interfaces showed a significantly lower machining tolerance and vertical microgaps than the titanium implant-CADCAM Milled zirconia abutment interfaces.