Systemic ozone therapy as an adjunctive treatment in guided bone regeneration: a histomorphometrical and immunohistochemical study in rats.

OBJECTIVES: To assess the effectiveness of ozone therapy in guided bone regeneration (GBR) for critical size calvarial defects in rats. MATERIALS AND METHODS: 96 male Wistar rats were divided into four groups (n = 6 each). An 8 mm critical defect was created in the calvaria of each rat. The groups were: BIO (porcine collagen membrane, BioGide®), BIO + OZ (membrane with systemic ozone therapy every 2 days), COA + OZ (blood clot with ozone therapy), and COA (blood clot only). Evaluations at 7, 15, 30, and 60 days included histological, histomorphometric, inflammatory profile, Micro-CT, and immunohistochemical analyses. Statistical analysis involved two-factor ANOVA with Tukey's post-hoc test for general data, and one-factor ANOVA with Holm-Sidak post-hoc test for Micro-CT data. RESULTS: The BIO + OZ group demonstrated superior bone regeneration with well-organized, mature bone tissue and significant bone formation at 30 and 60 days. The COA + OZ group showed early angiogenesis and reduced inflammation, resulting in complete defect closure by 30 days. The BIO group had good regeneration, but less mature tissue compared to BIO + OZ. The COA group exhibited limited bone formation and higher porosity. CONCLUSION: Ozone therapy positively influences bone regeneration by enhancing cell proliferation and the healing response. CLINICAL RELEVANCE: Improving regenerative processes with auxiliary therapies like ozone therapy can be significant for advancing dental reconstructions.

Inflammatory Profile of Different Absorbable Membranes Used for Bone Regeneration: An In Vivo Study.

BACKGROUND: Guided bone regeneration (GBR) has become a necessary practice in implantology. Absorbable membranes have shown advantages over non-absorbable membranes, such as blood support of bone tissue. This study aimed to evaluate five collagen membranes in rat calvaria critical-size defects through a histomorphometric analysis of the inflammatory profile during the initial phase of bone repair. MATERIALS AND METHODS: A total of 72 Albinus Wistar rats were used for the study, divided into six groups, with 12 animals per group, and two experimental periods, 7 and 15 days. The groups were as follows: the CG (clot), BG (Bio-Gide®), JS (Jason®), CS (Collprotect®), GD (GemDerm®), and GDF (GemDerm Flex®). RESULTS: Data showed that the BG group demonstrated an inflammatory profile with an ideal number of inflammatory cells and blood vessels, indicating a statistically significant difference between the JS and CS groups and the BG group in terms of the number of inflammatory cells and a statistically significant difference between the JS and CS groups and the GD group in terms of angiogenesis (p < 0.05). CONCLUSIONS: We conclude that different origins and ways of obtaining them, as well as the thickness of the membrane, can interfere with the biological response of the material.

Application of Tissue Engineering in Manufacturing Absorbable Membranes to Improve the Osteopromoting Potential of Collagen.

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm3) in the BG, followed by the CB (11.850 mm3), and CP (9.560 mm3) group. The collagen membranes associated with HA demonstrated an osteopromotive potential.