This book comprises of my research work which was carried out in Kothiwal dental college, research centre & hospital, moradabad, india. In this research work a new surgical technique was followed for surgical closure of oroantral fistula using collagen membrane and demineralized bovine bone graft and bone formation was evaluated. Oroantral fistula is a pathologic communication between oral cavity and maxillary antrum and persistence of which can cause serious problems to patients thus immediate closure is desirable. Although various surgical procedures had been advocated for closure of oroantral fistula, this technique has advantage over traditional method as their is Bone formation in the fistula site thus in future endosseous implants can be placed for rehabilitation of the patients.The bone formed by using these grafts is of good quality and have significant strength for implant placement.Furthermore studies using greater sample sizes are required to establish this new technique, the technique is very promising in future prospects .This research work was carried out obeying all the ethical prinicples.