J Periodontal Implant Sci. 2026 Jul 30. doi: 10.5051/jpis.2500240012. Online ahead of print.
ABSTRACT
PURPOSE: This pilot study investigated the effects of different extraction-socket bone-resorption patterns on alveolar ridge preservation (ARP) performed with an open-wound healing technique.
METHODS: Sites were divided into two groups according to cone-beam computed tomography (CBCT) findings obtained immediately after ARP surgery (T1): group 1 included sockets with vertical bone resorption >1/3 of the buccal/labial or lingual/palatal bone wall, and group 2 included sockets with vertical bone resorption ≤1/3 of the buccal/labial and lingual/palatal bone walls. Follow-up CBCT was performed approximately 5 months after surgery (T3). Hard-tissue changes were measured by superimposing CBCT images obtained at T0 (before tooth extraction), T1, and T3. Soft-tissue healing was evaluated at suture removal (T2), and biopsy specimens were collected before implant placement.
RESULTS: Sixteen participants with 19 sites completed this pilot study. All included patients underwent ARP with an intentionally exposed xenogeneic collagen matrix seal; however, one patient did not undergo implant-placement surgery at our hospital. Overall, CBCT measurements of ridge alterations showed excellent intra-rater reliability and minimal systematic bias. Bone resorption occurred in both groups (P<0.05), reflecting the natural bone-remodeling process. However, no intergroup differences were observed in horizontal or vertical dimensional changes. In addition, locally estimated scatterplot smoothing analysis identified bootstrap median inflection points below the 1/3 threshold, suggesting a possible nonlinear relationship between the vertical resorption proportion and three-dimensional changes. No statistically significant differences were observed in soft-tissue healing or implant-related outcomes. Histomorphometric evaluation of biopsy specimens showed new bone formation without signs of inflammation or fibrous encapsulation.
CONCLUSIONS: Within the limitations of this study, intentionally exposing the xenogeneic collagen matrix seal yielded comparable outcomes in non-contained and contained sockets. This finding may reflect the material’s ability to reduce the adverse effects of socket-wall resorption; however, larger multicenter studies are warranted.
TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR2300078331.
PMID:42596716 | DOI:10.5051/jpis.2500240012
