PurposeResorption of the alveolar bone is an unavoidable consequence of tooth extraction when appropriate alveolar ridge preservation (ARP) measures are not taken. The objective of this trial was to test the hypothesis that dimensional changes in the alveolar bone after tooth extraction would be reduced by inserting an equine collagen membrane and a collagen cone to fill and seal the alveolus (as ARP), in comparison to extraction with untreated alveoli.MethodsIn this randomized clinical trial, 31 patients were directly treated with the collagen material after extraction of a tooth from the maxilla (the ARP group). Twenty-nine patients served as the control group. After extraction, no further treatment (i.e., no socket preservation measures) was performed in the control group. Changes in the alveolar process immediately after extraction and after an 8 (±1)-week healing period were evaluated 3-dimensionally. Blinded analyses were performed after superimposing the data from the digitalized impressions and surfaces generated by cone-beam computed tomography.ResultsBoth the ARP and control groups showed a reduction of bone in the alveolar area after tooth extraction. However, significantly less bone resorption was detected in the clinically relevant buccal region in the ARP group. The median bone reduction was 1.18 mm in the ARP group and 5.06 mm in the control group (P=0.03).ConclusionsThe proposed hypothesis that inserting a combination material comprising a collagen cone and membrane would lead to a difference in alveolar bone preservation can be accepted for the clinically relevant buccal distance. In this area, implantation of the collagen material led to significantly less alveolar bone resorption. German Clinical Trials Register at www.drks.de, DRKS00004769.

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.

No abstract

No abstract