Evaluation of potential factors influencing variations in vertical soft tissue thickness at implant sites following the extraction of teeth with severe periodontitis: a prospective exploratory study.

PURPOSE: The vertical dimension of soft tissue is crucial for planning implant placement, tissue augmentation procedures, and maintaining the long-term health of peri-implant tissue. However, evidence regarding the variation in soft tissue thickness at implant sites and the factors influencing it is limited. This study investigated the potential determinants of soft tissue thickness variation at implant sites following tooth extraction due to severe periodontitis. METHODS: In total, 176 hopeless teeth in 94 patients with stage III/IV periodontitis were extracted due to severe periodontal destruction. Pre-extraction parameters were documented based on clinical and radiographic examinations, including tooth position; presence or absence of neighboring teeth; and the height difference between the proximal alveolar crest of the neighboring teeth and the extracted tooth. Socket morphology was examined clinically. During implant placement, vertical soft tissue thickness was categorized as thin (<2 mm), normal (≥2 mm to <5 mm), and thick (≥5 mm). Logistic regression analyses with generalized estimating equations identified potential factors influencing soft tissue thickness. Interactions among variables were evaluated. RESULTS: The mean vertical soft tissue thickness at the implant site was 3.8±1.3 mm. None of the implant sites showed thin soft tissue. Thick soft tissue was predominantly observed in the maxillary anterior region and was significantly associated with discrepancies in socket bone wall height. When pre-extraction periodontal therapy was administered, a notable increase in soft tissue wall height was significantly correlated with the presence of thick soft tissue at the implant site. The absence of neighboring teeth and a healing period of ≥2 months post-extraction did not show significant correlations with soft tissue thickness at the implant sites. CONCLUSIONS: The morphology of the extraction socket, potentially influenced by long-term periodontal inflammation, along with the position of the tooth site, may significantly contribute to variations of soft tissue thickness at the implant site.