Alveolar Ridge Preservation Using a Collagenated Xenograft: A Randomized Clinical Trial

Abstract

Objectives: This study sought to evaluate the efficacy of cancellous bovine bone mineral granules and 10% porcine collagen (deproteinized bovine bone mineral with collagen [DBBM-C]; (OCS-B Collagen® [Straumann XenoFlex], NIBEC, Korea) in a mouldable block form, with or without socket seal, using autogenous free gingival graft (FGG).

Methods: Fifty-four patients were included and randomly assigned to one of three groups: (1) spontaneous healing (control group), (2) alveolar ridge preservation (ARP) using DBBM-C (DBBM-C group), and (3) ARP employing DBBM-C sealed with FGG (DBBM-C/FGG group). Bone biopsy and implant fixture placement were performed 180 days after ARP. Cone-beam computed tomography, histological analysis, implant stability, and three-dimensional volumetric analysis were conducted.

Results: Of the 54 patients, 4 dropped out owing to loss of follow-up and osseointegration failure. The changes in alveolar bone during follow-up were not significantly different. Between 84- and 180-day postextraction, the volume of the DBBM-C and DBBM-C/FGG groups was maintained at 3 mm below the alveolar ridge crest (0.72 ± 0.80 mm, 6.05 ± 6.69%), whereas the volume in the control group decreased (-0.37 ± 1.31 mm, -2.10% ± 8.37%) (P = .026). The DBBM-C/FGG group exhibited less horizontal ridge resorption at 1 mm below the alveolar crest (-9.19 ± 5.09 mm, -73.67% ± 32.53%) between preextraction and 84 days postextraction (P = .049). In all groups, the implant stability quotient remained above 70.

Conclusions: Within the limitations of this study, both ARP using DBBM-C with and without socket sealing effectively preserved the width dimension of the alveolar ridge, with no significant difference in alveolar bone resorption. However, socket sealing appeared to enhance the stability of the bone graft and bone quality.

Clinical relevance: The use of DBBM-C for ARP seems to aid in volume maintenance as compared with spontaneous healing. Gingival sealing with an FGG can help maintain the width of the alveolar ridge. This clinical trial was not registered prior to participant recruitment and randomization. This study was registered at WHO ICTRP (https://trialsearch.who.int/Trial2.aspx?TrialID=KCT0008266).

Keywords: Alveolar bone grafting; Cone-beam computed tomography; Randomized controlled trial; Tooth socket; Wound healing; Xenograft.

Fig. 1

Study timeline and clinical photographs. A total of eight visits were made in 360 days, and the study was conducted in three groups; Control group: Natural healing, DBBM-C: DBBM-C was placed in the extraction socket and open healing was performed, and DBBM-C/FGG group: After placing DBBM-C in the socket, gingival sealing was performed using FGG from the palate. At visit 2, tooth extraction or ridge preservation was performed, a dental implant was placed at visit 5, and an implant prosthesis was installed at visit 7. Representative clinical photos of each group were presented.

Fig. 2

Flow chart of the study design. (A) Study flow chart: A total of 56 patients were enrolled in this study, and two patients were excluded, therefore, 54 patients were randomly assigned to three groups (n = 18). Four patients dropped out due to some reasons such as loss of follow-up or osseointegration failure, and finally, data were analysed from 17, 17, and 16 patients in each group. (B) Patient information: Information on age, sex, position, reason for tooth extraction, and implant diameter/length are shown.

Fig. 3

Cone-beam computed tomography (CBCT) radiographic analysis. (A) CBCT1: Baseline CBCT (0 days), CBCT2: immediately after implant placement (180 days). (B) Coronal section of the ridge with measurement reference lines. Vertical measurements: buccal bone height (BH) and lingual bone height (LH). Horizontal measurements: ridge width (RW) at 1 mm (RW-1), 3 mm (RW-3), and 5 mm (RW-5) from the bone crest. (C) Horizontal ridge changes at 1, 3, and 5 mm below the crest (RW-1, RW-3, and RW-5). (D) Changes in the vertical heights of the ridge at the buccal crest (BH) and lingual crest (LH) areas.

Fig. 4

Representative histological images of implant placement site with haematoxylin-eosin staining. The new bones were well made in all three groups. Residual cancellous bovine bone mineral granules (OCS-B) are shown in DBBM-C and DBBM-C/FGG groups. Left column: original magnification ×4, right column: original magnification ×10, bar = 250 µm, CT, connective tissue; VB, vital bone.