Effect of Er:YAG laser bone bed milling, with or without photobiomodulation, on the bone repair process of additive manufacturing implants in rats

The preparation of the bone bed for implant placement is a critical factor for successful osseointegration and is influenced by surgical techniques and instrumentation. In this context, a study was conducted to compare bone bed milling using an Er:YAG laser, with or without photobiomodulation, to conventional milling combined with Nd:YAG laser photobiomodulation. To assess the effects of Er:YAG laser milling, with or without photobiomodulation, on bone bed preparation and its potential to enhance osseointegration, 28 male rats underwent implant placement in their tibial metaphyses and were divided into four groups: conventional milling (CM), photobiomodulation + conventional milling (PBM + CM), Er:YAG laser milling (Er:YAG), and photobiomodulation + Er:YAG laser milling (PBM + Er:YAG). Euthanasia was performed 28 days after implant placement. Reverse torque testing and real-time PCR (RT-PCR) analysis were conducted to evaluate the expression of osteogenic markers, including ALP, IBSP, OCN, and RUNX2. Data were analyzed using the Shapiro-Wilk test, followed by one-way ANOVA and Tukey's post hoc test, where applicable, with a significance level of p ≤ 0.05. The Er:YAG group exhibited a significantly higher implant removal torque compared to the CM group. Additionally, the expression of genes associated with bone maturation (OCN), differentiation (RUNX2), and osteoblastic activity (ALP and IBSP) was significantly increased in both the Er:YAG and PBM + Er:YAG groups, indicating enhanced osteogenic potential. Thus, Er:YAG laser milling, with or without photobiomodulation using the Nd:YAG laser, may represent a promising alternative for bone bed preparation in implant procedures. However, further studies are required to better characterize bone healing and its long-term consolidation.