Morphoradiological Evaluation of Maxillary Alveolar Bone in Dental Implant Patients. Summary of the Doctoral Thesis

Abstract

The maxillary sinus floor augmentation using biomaterials of different types for enhancement and enforcement of dental implant stability has been widely used all over the world for a long while. However, literature still does not reveal long term researches where investigation on residual alveolar maxillary bone and maxillary sinus before and after augmentation procedure was done. Fifty nine patients were selected for the study. Bilateral or unilateral maxillary sinus floor augmentation procedures using different types of biomaterials were performed in these patients. Surgery was done in the Clinic of Maxillofacial Surgery, Riga Stradins University Institute of Stomatology. In total, seventy eight maxillary sinus augmentation procedures were performed; before and after surgery all operation sites and sinuses were investigated radiologically applying cone beam computed tomography. Preoperatively there were detected linear and radiological grey levels of residual alveolar bone and a volume of maxillary sinus was identified. Repeated cone beam computed tomography scanning was done at least one year after surgery. In the second scan the following measurements were taken: linear measurements of augmented area, radiological grey level in several sites, and volume of the sinus. Radiologically detectable changes of sinus mucosa, opening and concha bullosa were detected both in pre and postoperative scans. There also was collected and analysed a demographic data, then a connection between demographic data and radiological results was analysed. The results revealed that bone substitute materials increase mineralization level of residual alveolar maxillary bone, but the radiological grey level of augmented area decrease over the time. These results were acquired radiologically, and in addition they are supported histologically by the literature data. Correct radiological grey level of augmented area and supporting bone around the dental implants can be detected using cone beam computed tomography method if metal artefact influence is considered. Radiological investigation of maxillary sinus before and after augmentation procedure has informative character. Such information prevents post–operative complications and helps to avoid unexpected situations during the surgical procedure. The study consists of 144 pages; it includes 204 references. Copies of two documents are added.