The Effect of Er:YAG Laser Biomodification of the Implant Site Surface on Osseointegration: A Randomized Controlled Clinical Study

Background: Er:YAG laser (λ = 2940 nm) biomodification of the implant osteotomy site removes the smear layer after rotary preparation and may enhance bone-implant contact. This randomized controlled clinical study evaluated implant stability dynamics following Er:YAG laser biomodification using resonance frequency analysis (RFA). Methods: Ninety patients were randomized 1:1 into a case group (n = 45; rotary osteotomy + Er:YAG biomodification; 400 mJ, 17 Hz) and a control group (n = 45; rotary osteotomy alone). Implant stability quotient (ISQ) was measured by RFA in vestibulo-oral (VO) and mesiodistal (MD) directions at placement, days 10, 20, 30, and month 3. Results: The case group showed significantly higher ISQ values at all time points in both directions (t-test, p < 0.05). Repeated measures ANOVA revealed a significant time × group interaction in the MD direction (F = 14.461, p < 0.001, partial η² = 0.341). Primary VO ISQ: 75.04 ± 4.27 (cases) vs. 72.29 ± 3.38 (controls); primary MD ISQ: 76.49 ± 4.29 vs. 72.89 ± 2.29. The proportion achieving ISQ ≥ 70 was consistently higher in the case group. Conclusions: Er:YAG laser biomodification combined with rotary osteotomy yields higher, more stable ISQ values throughout early healing in mandibular D2/D3 bone, potentially supporting shorter healing intervals and early loading in selected clinical situations.