Poor bone quality and quantity are often related to implant failure. Synthetic bone grafts may be used to enhance the formation of new bone in bone defects. The purpose of this animal study was to determine the efficacy of bioactive glass particles of narrow size range (300 to 335 ìm, Biogran) in the treatment of bone defects prior to implant placement. On both sides of the mandible of six beagle dogs, areas of partial edentulousness were created by the removal of the intra-alveolar septa to obtain large defects, instantly filled on one side with bioactive glass particles. The other side was left empty as a control. After a healing period of 4 months, three oral implants each were placed in the glass-treated area and in the control zone. In three dogs, the implants were left subgingival for 3 months after which histologic sections were made. In the remaining three dogs, the implants were functionally loaded with a fixed partial prosthesis for 7 weeks before sacrifice. Qualitative and quantitative analysis of both groups revealed statistically significantly more bone tissue and higher remodeling activity at the interface and at a distance of implants placed in glass-treated areas, compared to implants placed in untreated regions. Implant placement in bioactive glass-filled defects was not jeopardized, on the contrary. Keywords: beagle dog, bioactive glass, bone remodeling, fixed partial prosthesis, fluorescence microscopy, histomorphometry, occlusal loading, oral implants