Comparative Evaluation of Peri-implant Strain Generated by Implant-supported Crowns Fabricated with Different Restorative Materials: An In Vitro Study

Purpose: To evaluate and compare peri-implant strain generated by polyetheretherketone (PEEK), zirconia, and porcelain-fused-to-metal (PFM) screw- and cement-retained implant-supported crowns using strain gauges. Materials and methods: A 4 × 12 mm implant (Dentium) was placed in a polymethyl methacrylate (PMMA) block. A prefabricated standard abutment was screwed onto the implant and scanned using a lab scanner. Thirty crowns for the three study groups (<i>n</i> = 10 each), namely PEEK, zirconia, and PFM, were fabricated and screwed onto the implant. Four strain gauges were bonded on the test block around the implant neck at buccal, lingual, mesial, and distal locations. An axial load of 250 N was applied in the center of the crown using a universal testing machine (UTM). Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) test (<i>p</i> < 0.05). Results: One-way ANOVA revealed a significant difference (<i>p</i> < 0.001) among the groups. PEEK (1795.7 µε) showed significantly lower values of microstrain compared to zirconia (3110 µε) and PFM crowns (3435.9 µε). In all groups, strain was found to be higher on the buccal aspect, followed by the distal, lingual, and least in the mesial region. Conclusion: Peri-implant strain is influenced by the type of restorative material. PEEK significantly reduced the peri-implant strain relative to zirconia and PFM implant-supported crowns. PEEK may be a more biomechanically favorable material for implant-supported restorations, offering better stress distribution and reducing the risk of excessive peri-implant bone strain. How to cite this article: Kaur K, Sehgal K, Sahore P, <i>et al.</i> Comparative Evaluation of Peri-implant Strain Generated by Implant-supported Crowns Fabricated with Different Restorative Materials: An <i>In Vitro</i> Study. Int J Prosthodont Restor Dent 2025;15(1):20–26.