Dimensional Changes of the Soft Tissue after Alveolar Ridge Preservation with a Collagen Material. A Clinical Randomized Trial

BACKGROUND: Reduction of the soft tissue is an unavoidable consequence of tooth extraction without appropriate measures of Alveolar Ridge Preservation (ARP). OBJECTIVES: The objective of this study is the volumetric investigation of the dimensional change of the soft tissue post tooth extraction to compare an Alveolar Ridge Preservation (ARP) measure with the insertion of a combination material with a collagen cone to fill the alveolus, combined with a collagen membrane, with untreated extraction alveoli. METHODS: In the context of a randomized clinical trial, 31 patients were treated with the combination material directly post tooth extraction in the maxilla (ARP). In 29 further patients, the extraction alveoli were left without further measures (control group). The changes of the soft tissue contour were measured 6 (+/- 1) weeks post extraction. The measurements were performed by superimposing digital models. The groups were compared using the Wilcoxon rank-sum-test. RESULTS: The premolar subgroup revealed a significant difference of the soft tissue dimension post insertion of a collagen material into the alveolus in comparison to untreated alveoli. In these cases, the mean loss of soft tissue volume after use of the collagen material was significantly lower. CONCLUSION: The proposed hypothesis that there is a difference of the soft tissue preservation between alveoli with and without the use of a collagen material can be accepted with restrictions to the premolar region. A statistically significant lower volume reduction of the soft tissue by implantation of the collagen material could be detected with premolars.