The effect of different soft-tissue management techniques for alveolar ridge preservation: a randomized controlled clinical trial

PURPOSE: For alveolar ridge preservation, various treatment protocols have been described. While most studies focus on the effect of the bone graft material, the aim of this study was to analyze the influence of different soft-tissue management techniques on the soft and hard tissue. METHODS: A total of 20 maxillary extraction sockets were grafted with an anorganic xenogenic bone graft and then randomly treated with either a combined epithelialized-subepithelial connective tissue graft (CECG) or a porcine collagen matrix (CM) placed in labial and palatal tunnels. Measurements of soft-tissue thickness were performed at tooth extraction (T0), implant insertion (T1) and second stage surgery (T2). RESULTS: In the CECG group, gingival thickness was 1.18 ± 0.56 mm (T0), 1.29 ± 0.26 mm (T1) and 1.2 ± 0.32 mm (T3). In the CM group, the measurements were 1.24 ± 0.50 mm (T0), 1.6 ± 0.6 mm (T1) and 1.7 ± 1.06 mm. Thus, there was an overall increase in gingival thickness from T0 to T2 of 0.02 ± 0.66 mm (CECG) compared to 0.46 ± 0.89 mm (CM). The thickness of keratinized soft-tissue was 3.91 ± 1.11 mm (CECG) and 4.76 ± 1.48 mm (CM) before extraction and 3.93 ± 1.17 mm (CECG) and 4.22 mm ± 1.26 mm (CM) at implant follow-up. Mean peri-implant probing depths were 3.15 ± 1.39 mm (CECG) and 3.41 ± 0.99 mm (CM). CONCLUSIONS: After ridge preservation, comparable soft-tissue parameters were observed in both groups, whether treated with a collagen matrix or a combined autologous connective tissue graft. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40729-021-00390-3.