Vertical marginal gap evaluation of PEEK and Zirconia crowns using extra-oral scanner and CAD/CAM systems (An Invitro study).

Abstract

Results:The average (mean) for the marginal gap of proximal, buccal and lingual surfaces of both PEEK, and zirconia materials were: 409.097 μm, 112.869 μm, 198.563 μm, for PEEK and, 105.085 μm, 27.659 μm, 45.135 μm for zirconia respectively. Statistical analysis using t -test for two independent samples revealed that PEEK material showed a significantly higher marginal gap than z. irconia material. Conclusion:PEEK crowns had a higher marginal gap than clinically acceptable limit, while zirconia crowns exhibited much lower measurements.

Effect of coping materials zirconia or polyetheretherketone with different techniques of fabrication on vertical marginal gap and fracture resistance of posterior crowns with composite veneering

“…Roy et al [ 41 ] reported the same conclusions in an in vivo experiment. Moreover, Aula RA et al [ 42 ] concluded that PEEK crowns had a marginal gap of 409.09 μm, 112.86 μm, and 198.56 μm for proximal, buccal and lingual surfaces, respectively, which is higher than the clinically acceptable limit, while zirconia crowns exhibited much lower measurements, 105.08 μm proximal, 27.65 μm buccal, and 45.13 μm lingual. The difference might be attributed to the variation in methodology, as they used 3-unit FDP, and the marginal gap was assessed using a stereomicroscope at 160X.…”

“…Moreover, these findings might be due to PEEK's semicrystalline structure, which includes fillers entrapped in a resin matrix yielding a greater marginal gap during manufacturing than zirconia, which has a polycrystalline structure [ 42 ].…”