The use of ozonated olive oil mixed with bone substitute to help in regeneration of intrabony peridontal defect. Within the limitations of the present study we can conclude that: The use of ozonized oil mixed bone graft showed little non-significant improvement in intrabony defect fill compared to the control graft defect fill. The use of ozonized olive oil in intra-bony defects increase GCF level and availability of bone morphogenic protein 2 significantly compared to the control non ozonized group. The use of ozonated olive oil once during mixing it with bone has no significant difference than subsequent use each week.