Abstract

Introduction: The efficacy of alveolar ridge preservation (ARP) in preserving the bone after tooth extractions and before rehabilitation with an implant-supported restoration is examined. A new, non-invasive measurement method to determine the extent of bone preservation is presented. This measurement method is based on a 3D comparison of the condition immediately after extraction with the data of a cone-beam computed tomography (CBCT) eight weeks after extraction.
Method: The study is a single-center, randomized, controlled parallel-group clinical investigation. 88 patients who required extraction of a maxillary tooth participated in the study. In 44 patients (intervention group), the socket is filled with a combination of a collagen plug and a collagen membrane introduced in the empty socket immediately after tooth removal (ARP). The 44 patients (control group) experience unassisted socket healing the hyporeflective space. Primary endpoints are (1) bone loss after tooth extraction; (2) the preservation of the alveolar ridge (soft tissue and bone); (3) the need for augmentation during the subsequent implant treatment; and (4) the question whether ARP is more costeffective than the therapy with unassisted socket healing. Patients will be followed for 5 years.
Discussion: The extent of bone resorption after tooth extraction significantly influences the subsequent implant placement. Preserving the bone as well as possible is of great importance for the stability, prosthetically correct position and long-term functional success of the implantological treatment. A new, non-invasive method, without additional, study-related X-ray exposure, presented here for the first time, the change in volume of the bone bed can be analyzed. The preliminary results of this feasibility test report a median value of buccal and palatal bone loss of 6.2 mm (control)/4.4 mm (test) and 2.5 mm (control)/2.8 mm (test), respectively. These values are comparable to studies that also determined bone resorption by CBCT.