Calvaria Critical Size Defects Regeneration Using Collagen Membranes to Assess the Osteopromotive Principle: An Animal Study.

Guided bone regeneration (GBR) is a common practice in implantology, and it is necessary to use membranes in this process. The present study aimed to evaluate the osteopromotive principle of two porcine collagen membranes in critical-size defects at rats calvaria. Ninety-six Albinus Wistar rats were divided into BG (positive control), JS, CS, and CG (negative control) groups and were sacrificed at 7, 15, 30, and 60 days postoperatively. The samples were assessed by histological, histometric, immunohistochemical, and microtomographic analyses. More intense inflammatory profile was seen in the JS and CS groups (p < 0.05). At 60 days, the JS group showed a satisfactory osteopromotive behavior compared to BG (p = 0.193), while CS did not demonstrate the capacity to promote bone formation. At the immunohistochemical analysis, the CS showed mild labeling for osteocalcin (OC) and osteopontin (OP), the JS demonstrated mild to moderate for OC and OP and the BG demonstrated moderate to intense for OC and OP. The tridimensional analysis found the lowest average for the total volume of newly formed bone in the CS (84,901 mm2), compared to the BG (319,834 mm2) (p < 0.05). We conclude that the different thicknesses and treatment techniques of each membrane may interfere with its biological behavior.

Do the New Protocols of Platelet-Rich Fibrin Centrifugation Allow Better Control of Postoperative Complications and Healing After Surgery of Impacted Lower Third Molar? A Systematic Review and Meta-Analysis.

PURPOSE: Platelet concentrate generation protocols have undergone several modifications in recent years; in light of these new developments, this study review aims to evaluate the effects of platelet-rich fibrin (PRF) and the new centrifugation protocols, advanced platelet-rich fibrin (A-PRF), and leukocyte platelet-rich fibrin (L-PRF), after extraction of impacted mandibular third molar. Specifically, we assessed pain control, edema, trismus, and soft tissue healing, and also measured the degree of periodontal regeneration adjacent to the second molar. METHODS: PubMed, MEDLINE, EMBASE, Web of Science, Virtual health library (BVS), and Cochrane Library were searched up to Julye 2021; randomized controlled studies were included. This report followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and PICO (population, intervention, comparison, outcome) questions. This review has been registered at the International Prospective Register of Ongoing Systematic Reviews (PROSPERO) under the number CRD42019136701. The risk of bias screening and data extraction was performed according to the guidelines recommended by Cochrane. The quantitative analysis was performed using RevMan version 5.4. RESULTS: Of 17 studies included in the systematic review, 11 were eligible for the meta-analysis. The use of L-PRF was not associated with better soft tissue healing at day 7. (standard mean difference = -0.70; 95% confidence interval, -3.50 to 2.10; Z = 0.49; P = .62; heterogeneity = 0.00001; I2 = 97%). With L-PRF, qualitative analysis revealed better pocket depth and insertion level, and also better pain control at 1 and 3 days. With A-PRF, a lower consumption of analgesics was observed than with L-PRF. With both A-PRF and L-PRF, better control of edema (but not trismus) was observed. CONCLUSIONS: The use of L-PRF and A-PRF allows better control of pain and edema compared with the use of standard PRF protocols, but neither has an effect on trismus. The PRF and L-PRF protocols improve soft tissue healing, although not to a statistically significant degree; however, they could improve probing depth at the third month after third molar surgery.

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.

Potencial de regeneração óssea guiada das membranas de colágeno porcino (Jason e Collprotect Straumann®): estudo histológico, histomorfométrico e Micro TC em defeitos ósseos de calvária de ratos / Potential for guided bone regeneration of porcine collagen membranes (Jason and Collprotect Straumann): histological, histomorphometric, and Micro CT study in bone defects of rat calvaria

A regeneração óssea guiada (ROG) tornou-se uma prática comum na Implantodontia e para sua realização, é necessário o uso de membranas que auxiliem neste processo. As membranas absorvíveis têm mostrado vantagens em relação às membranas não absorvíveis e entre as características mais relevantes das membranas absorvíveis estão: o aporte vascular, suporte mecânico do tecido ósseo e a não necessidade de um segundo estágio cirúrgico. Esse estudo teve como objetivo avaliar e comparar, por meio das análises histológica, histomorfométrica e Micro TC o potencial osteopromotor de duas membranas de colágeno porcino comercialmente disponíveis em defeitos críticos de calvária de ratos. Para o estudo foram utilizados 96 ratos Albinus Wistar, divididos em quatro grupos, sendo 24 animais para cada grupo: Grupos BG (BioGide®); JS (Jason®); CS (Collprotect®) e CG (Coágulo) analisados em quatro tempos experimentais, 7, 15, 30 e 60 dias. Os resultados mostraram um perfil inflamatório mais agressivo dos grupos JS e CS em relação ao grupo BG (p<005). O grupo JS, aos 60 dias apresentou um potencial osteopromotor satisfatório ao compara-lo com o grupo BG (p=0,193) e o grupo CS demonstrou o pior desempenho osteopromotor. Na análise tridimensional, os resultados anteriores foram confirmados com o pior desempenho em relação a menor média de tecido ósseo neoformado para o grupo CS de 84,901 mm², JS com 246,802 mm² e BG 319,834 mm² (p<0,05). Podemos concluir que apesar das membranas serem compostas pelo mesmo material, as diferentes áreas de obtenção, espessuras e técnicas de tratamento da membrana, podem interferir no seu comportamento biológico em relação á quantidade de osso neoformado e que o grupo CS apresentou os piores resultados quando comparado aos grupos JS e BG(AU)

Guided bone regeneration (ROG) has become a common practice in Implantology and for its realization, it is necessary to use membranes that assist in this process. Absorbable membranes have shown advantages over non-absorbable membranes and among the most relevant characteristics of absorbable membranes are vascular supply and mechanical support of bone tissue. This study aimed to evaluate and compare, through histological, histomorphometric, and Micro CT analyzes, the osteopromotive factor of two commercially available porcine collagen membranes in critical calvaria defects in rats. 96 Albinus Wistar rats were used for the study, divided into four groups, 24 animals for each group: BG Groups (BioGide®); JS (Jason®); CS (Collprotect®) and CG (Clot) analyzed in four experimental times, 7, 15, 30 and 60 days. The results showed a more aggressive inflammatory profile of the JS and CS groups in relation to the BG group (p <0.05). The JS group, at 60 days, presented a satisfactory osteopromotive factor when comparing it with the BG group (p = 0.193) and the CS group demonstrated the worst osteopromotive performance. In the three-dimensional analysis, the previous results were confirmed with the worst performance in relation to the lowest average total volume of newly formed bone for the CS group of 84,901 mm², JS with 246,802 mm² and BG 319,834 mm² (p<0,05). We can conclude that although the membranes are composed of the same material, the different areas of obtaining, thicknesses, and techniques of treatment of the membrane, can interfere in its biological behavior in relation to the amount of newly formed bone and that the CS group presented the worst results among the JS and BG group(AU)

Is the Bacterial Cellulose Membrane Feasible for Osteopromotive Property?

Guided bone regeneration was studied to establish protocols and develop new biomaterials that revealed satisfactory results. The present study aimed to comparatively evaluate the efficiency of the bacterial cellulose membrane (Nanoskin®) and collagen membrane Bio-Gide® in the bone repair of 8-mm critical size defects in rat calvaria. Seventy-two adult male rats were divided into three experimental groups (n = 24): the CG-membrane-free control group (only blood clot, negative control), BG-porcine collagen membrane group (Bio-Guide®, positive control), and BC-bacterial cellulose membrane group (experimental group). The comparison periods were 7, 15, 30, and 60 days postoperatively. Histological, histometric, and immunohistochemical analyses were performed. The quantitative data were subjected to 2-way ANOVA and Tukey's post-test, and p < 0.05 was considered significant. At 30 and 60 days postoperatively, the BG group showed more healing of the surgical wound than the other groups, with a high amount of newly formed bone (p < 0.001), while the BC group showed mature connective tissue filling the defect. The inflammatory cell count at postoperative days 7 and 15 was higher in the BC group than in the BG group (Tukey's test, p = 0.006). At postoperative days 30 and 60, the area of new bone formed was greater in the BG group than in the other groups (p < 0.001). Immunohistochemical analysis showed moderate and intense immunolabeling of osteocalcin and osteopontin at postoperative day 60 in the BG and BC groups. Thus, despite the promising application of the BC membrane in soft-tissue repair, it did not induce bone repair in rat calvaria.

Osteopromotion Capacity of Bovine Cortical Membranes in Critical Defects of Rat Calvaria: Histological and Immunohistochemical Analysis.

Membranes that aid the guided bone regeneration (GBR) process have been the subject of studies of compatible biomaterials that contribute to this repair process. The present study compared different membranes used in critical-size defects of rat calvaria by assessing GBR as well as histological, histomorphometric, and immunohistochemical reactions. Forty-eight male albino Wistar rats were randomly allocated into four groups (n = 12 each), namely, C: membrane-free control group (only blood clot, negative control group); BG: porcine collagen membrane group (Bio-Gide®, positive control group); GD: bovine cortical membrane group (first experimental group); and GDF: thicker bovine cortical membrane group (second experimental group). Rats were euthanized at 30 and 60 days postoperatively. Quantitative data from the histometric analysis were submitted to two-way ANOVA and Tukey's posttest when p < 0.05. Histomorphometric results of the thicker bovine cortical membrane at 30 and 60 days were promising, showing improved new bone formation values (p < 0.05), and the CD group presented similar results in both analysis periods, being surpassed only by the GDF group (p < 0.05). The immunohistochemical results were associated with the histomorphometric data. A less-thick membrane also assisted in GBR. All membranes promoted GBR, especially the positive control and experimental groups.