In Vitro Er:YAG Retrieval of Zirconia Crowns from Polyetheretherketone and Titanium Abutments

Aim: To compare Er:YAG laser-assisted retrieval of zirconia crowns cemented on titanium and polyetheretherketone (PEEK) abutments by evaluating retrieval time, temperature changes at crown, abutment, and fixture levels, and post-retrieval surface integrity. Materials and methods:This in vitro comparative study included 22 CAD/CAM zirconia crowns divided into two equal groups (n = 11 each).Group A crowns were cemented onto titanium abutments and Group B crowns onto milled PEEK abutments using self-adhesive resin cement.After standardized storage, crowns were irradiated with an Er:YAG laser at 2940 nm under continuous water cooling.Crown, abutment, and fixture temperatures were recorded using a calibrated thermocouple thermometer, and retrieval time was recorded in seconds.Retrieved specimens were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).Data were recorded and statistically analyzed using independent-samples t-tests, with p < 0.05 considered significant.Results: Titanium showed significantly higher mean crown temperature than PEEK (32.44 ± 1.00 vs 30.08 ± 0.93 °C; p < 0.001), higher abutment temperature (31.35 ± 0.57 vs 29.14 ± 0.99 °C; p < 0.001), and higher fixture temperature (30.36 ± 0.93 vs 27.16 ± 1.13 °C; p < 0.001).Retrieval time was comparable between groups (124.82 ± 4.09 vs 123.73 ± 3.13 seconds; p = 0.489).No relevant structural or elemental alteration was observed after irradiation.Conclusion: Er:YAG laser irradiation enabled predictable retrieval of zirconia crowns from both abutment materials.Polyetheretherketone performed comparatively better by producing significantly lower crown, abutment, and fixture temperatures, while retrieval time remained statistically similar to titanium.Clinical significance: Laser-assisted retrieval may reduce destructive sectioning of cement-retained zirconia implant crowns.The lower heat transfer observed with PEEK suggests a clinically translational thermal safety advantage when conservative crown retrieval and potential reuse are desired.