Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Turkey
Approval Date: 2014
Thesis Language: Turkish
Student: Elif Peker
Supervisor: İNCİ RANA KARACA
Abstract:Restoration of the edentulous posterior maxilla with dental implants is difficult due to some anatomical limitations. Maxillary sinus augmentation has been proposed as an appropriate treatment option for providing adequate bone height for dental implant placement in posterior maxilla. The aim of the present study was histologic, histomorphometric and immunohistochemical evaluation of the effectiveness of demineralized bone matrix and collagenated heterologous bone grafts used alone or in combination with platelet rich fibrin on bone healing in sinus floor augmentation. In this study 36 New Zealand rabbits were used. 72 bone defects were obtained by performing bilateral sinus floor augmentation and they divided into 4 groups according to the grafting materials employed: demineralized bone matrix (DBM), platelet rich fibrin (PRF) combined with DBM, collagenated heterologous bone graft (CHBG) and PRF combined with CHBG groups. The rabbits were sacrificed at 2,4 and 8 weeks after surgery. All samples were evaluated by histological, histomorphometrical and immunohistochemical examinations. According to these examinations, all materials were biocompatible. Inflammation was observed to be more intense in PRF used study groups at the 2nd week. Inflammation degree was higher in DBM groups than CHBG groups and it decreased beginning from the 2nd week. DBM particles were resorbed during the study period and the amount of DBM particles decreased from 2 to 8 weeks. The amount of CHBG particles decreased from 2 to 4 weeks and remained stable in the next 4 weeks. New bone formation was started by the 2nd week and increased from 2 to 8 weeks in all groups. Osteoblastic proliferation was observed to be higher in CHBG combined with PRF group than CHBG-only group at the 2nd week. More bone formation occurred in the DBM-only and DBM combined with PRF groups at the end of the study period. The effect of PRF on graft materials used for bone healing was not statistically significant but it was thought to be a positive influence on early bone healing when it is used together with CHBG.