Efficacy of collagenated bone substitutes for bone regeneration in two-wall-damaged extraction sockets without barrier membranes.

OBJECTIVES: To evaluate ridge dimensional changes following alveolar ridge augmentation in two-wall-damaged extraction sockets without a barrier membrane, using two types of collagenated bone substitutes i. cross-linked (CL-CB) and ii. non-cross-linked (NCL-CB). MATERIALS AND METHODS: Two-wall defects were created in mandibles of seven beagle dogs and treated in three groups: (i) no grafting (control), (ii) sockets filled with NCL-CB, and (iii) sockets filled with CL-CB. No barrier membrane was used. One animal was sacrificed after 1 week of healing for tissue assessments (n = 1), and the other six were sacrificed after 8 weeks of healing for microcomputed tomography (micro-CT) and histological analyses (n = 6). RESULTS: Compared to unextracted sites, radiographic analysis revealed that the alveolar ridge dimension decreased to 83.29 +/- 24.96% in group NCL-CB, 73.46 +/- 16.59% in group CL-CB and 55.41 +/- 12.95% in non-grafted sites (intergroup p = 0.062). Histological analysis showed that compared to baseline values the ridge area decreased to 68.75 +/- 14.20% in the non-grafted group, 79.88 +/- 20.05% in the NCL-CB group and 76.10 +/- 21.09% in the CL-CB group with no significant differences between the groups (p > 0.05). Qualitative histological analyses revealed significantly less mineralized tissue in both test groups, amounting to 25.28 +/- 10.40% in group NCL-CB, 29.86 +/- 12.04% in group CL-CB, and 67.15 +/- 14.35% in non-grafted sites (intergroup p < 0.05). CONCLUSION: The efficacy of alveolar ridge augmentation using either cross-linked or non-cross-linked collagenated bone substitutes alone might be limited in severely damaged sockets such as those with two-wall defects. CLINICAL RELEVANCE: In situations where sockets are extensively damaged, like those with two-wall defects, relying solely on soft-type bone block substitutes without a barrier membrane may not provide sufficient bone regeneration. This study highlights the importance of considering additional regenerative strategies, such as the use of barrier membranes, to enhance clinical outcomes.