Immunolocalization of markers for bone formation during guided bone regeneration in osteopenic rats

Objective The aim of this paper was to evaluate the repair of onlay autogenous bone grafts covered or not covered by an expanded polytetrafluoroethylene (e-PTFE) membrane using immunohistochemistry in rats with induced estrogen deficiency. Material and Methods Eighty female rats were randomly divided into two groups: ovariectomized (OVX) and with a simulation of the surgical procedure (SHAM). Each of these groups was again divided into groups with either placement of an autogenous bone graft alone (BG) or an autogenous bone graft associated with an e-PTFE membrane (BGM). Animals were euthanized on days 0, 7, 21, 45, and 60. The specimens were subjected to immunohistochemistry for bone sialoprotein (BSP), osteonectin (ONC), and osteocalcin (OCC). Results All groups (OVX+BG, OVX+BMG, SHAM+BG, and SHAM+BMG) showed greater bone formation, observed between 7 and 21 days, when BSP and ONC staining were more intense. At the 45-day, the bone graft showed direct bonding to the recipient bed in all specimens. The ONC and OCC showed more expressed in granulation tissue, in the membrane groups, independently of estrogen deficiency. Conclusions The expression of bone forming markers was not negatively influenced by estrogen deficiency. However, the markers could be influenced by the presence of the e-PTFE membrane

Effect of two corticotomy protocols on periodontal tissue and orthodontic movement

Objective: To compare two corticotomy surgical protocols in rats to verify whether they alter conventional orthodontic movement. Methodology: Sixty Wistar rats were divided into three groups – orthodontic movement (CG), orthodontic movement and corticotomy (G1) and orthodontic movement with corticotomy and decortication (G2) – and euthanized after 7 and 14 days. Tooth movement (mm), bone volume fraction and bone volume ratio to total volume (BV/TV), and bone mineral density (BMD) were evaluated by micro-CT. The total amount of bone was measured in square millimeters and expressed as the percentage of bone area in the histomorphometry. The number of positive TRAP cells and RANK/RANKL/OPG interaction were also investigated. Results: Day 14 showed a statistically significant difference in orthodontic tooth movement in CG compared with G1 (7.52 mm; p=0.009) and G2 (7.36 mm; p=0.016). A micro-CT analysis revealed a difference between CG, G1 and G2 regarding BV/TV, with G1 and G2 presenting a lower BV/TV ratio at 14 days (0.77 and 0.73 respectively); we found no statistically significant differences regarding BMD. There was a difference in the total amount of bone in the CG group between 7 and 14 days. At 14 days, CG presented a significantly higher bone percentage than G1 and G2. Regarding TRAP, G2 had more positive cells at 7 and 14 days compared with CG and G1. Conclusion: Corticotomy accelerates orthodontic movement. Decortication does not improve corticotomy efficiency

The influence of LLLT applied on applied on calvarial defect in rats under effect of cigarette smoke

Objective: Considering the global public health problem of smoking, which can negatively influence bone tissue repair, the aim of this study is to analyze the influence of photobiomodulation therapy (PBM) on calvaria defects created surgically in specimens under the effect of cigarette smoke and analyzed with use of histomorphometric and immunohistochemistry techniques. Methodology: Calvaria defects 4.1 mm in diameter were surgically created in the calvaria of 90-day-old rats (n=60) that were randomly divided into 4 experimental groups containing 15 animals each: control group (C), smoking group (S), laser group (L), and smoke associated with laser group (S+L). The animals were subjected to surgery for calvaria defects and underwent PBM, being evaluated at 21, 45, and 60 days post-surgery. The specimens were then processed for histomorphometric and immunohistochemistry analyses. The area of bone neoformation (ABN), percentage of bone neoformation (PBNF), and the remaining distance between the edges of the defects (D) were analyzed histometrically. Quantitative analysis of the TRAP immunolabeled cells was also performed. The data were subjected to analysis of variance (ANOVA) in conjunction with Tukey’s test to verify the statistical differences between groups (p<0.05). Results: The smoking group showed less ABN compared to the other experimental groups in all periods, and it also showed more D at 21 days compared to the remaining groups and at 45 days compared to the laser group. The smoking group showed a lower PNBF compared to the laser group in all experimental periods and compared to smoking combined with LLLT group at 21 days. Conclusions: PBM acted on bone biomodulation, thus stimulating new bone formation and compensating for the negative factor of smoking, which can be used as a supportive therapy during bone repair processes

Effect of systemic antibiotic and probiotic therapies as adjuvant treatments of subgingival instrumentation for periodontitis: a randomized controlled clinical study

Objective: This study assessed the efficacy of two adjunct therapies (antibiotic and probiotic) for periodontal treatment based on clinical and immunological parameters in patients with Stage II and III Grade B periodontitis. Methodology: 45 patients were randomly allocated into three groups: control group (CG); antibiotic group (GAtb), in which 500 mg amoxicillin + 400 mg metronidazole were used; and probiotic group (GProb), for which Lactobacillus reuteri was used. Patients received medications after undergoing periodontal debridement. Clinical and immunological parameters were assessed at baseline, 30 days, and 90 days. Results: All therapies reduced bleeding on probing (BoP) in the evaluated periods, and the GAtb had a greater reduction at 90 days (p=0.03). The GProb group showed better results for plaque index (PI) and gingival recession (GR) compared to the GAtb at 90 days (p=0.0014; p=0.006). The area of inflammation (PISA Index) significantly decreased in all therapies in the evaluated periods. Therapies had no significant differences regarding moderate pockets. The GAtb had a greater reduction in probing depth (PD) for deep pockets (p=0.03) at 90 days and in the number of deep pocket sites at 30 days (p=0.04). The occurrence of adverse effects was commonly reported in the GAtb as a percentage per patient. The GAtb had a significant reduction in the concentration of interleukins IL-1β and IL-8 and an increase in IL-10 and TNF-α. The CG had a reduction in IL-6 and IL-1 β, whereas in the GProb there was no difference. Conclusion: After three months, none of the adjuvant therapies provided any additional benefit for subgingival instrumentation

Effect of Photobiomodulation Therapy Associated With Biphasic Phosphate Calcium on Bone Repair: A Histomorphometric Study in Rats

Background: This study aimed to investigate the effects of photobiomodulation therapy associate with biphasic calcium phosphate on calvaria critical defects in rats. Methods: Forty-eight (90days old) adult male rats (Rattus norvegicus, Albinus variation, Wistar) received critical defects with 5 mm in diameter were made on their skull and were randomly assigned into the groups: C-blood clot, B-biphasic calcium phosphate, L-photobiomodulation therapy and B+L-biphasic calcium phosphate+photobiomodulation therapy. A low-level GaAlAs was applied in a single dose tran-surgically, in a wavelength 660 nm, total dense energy density of 45 J/cm2. At 30 and 60 days, animals from each group were euthanized. Histological and histomorphometric analyzes were performed.  Results: In 30 days, almost all specimens (C, L, B and B+L) showed bone neoformation areas in regions near the borders of the surgical defect. In 60 days, in many specimens (C, L, B, B+L), it was possible to see a narrow neoformed bone structure along almost the whole extension of the surgical defect, though being thinner than the original calvary bone.  Data were recorded as mean ± standard deviation, after normality was tested, suitable statistical test was applied (α= 5%). At 60 days, there was a statistically significant difference when comparing the proportion of neoformation area between group L (0.52%±0.13) and B+L (0.20%±0.08). Group L showed a difference compared with all the groups when comparing the remaining distance between de edges of neoformed bone (C×L, p=0.0431; B×L, p=0.0386; L×B+L, p=0.0352), demonstrating a great defect closure.  Conclusions: Our findings suggest that photobiomodulation therapy applied at 45 J/cm² resulted in the highest percentage of bone neoformation area after 60 days, although biphasic calcium phosphate exerts some osteogenic activity during bone repair, photobiomodulation therapy is not able to modulate this process

Reparação de enxertos ósseos autógenos recobertos ou não por membrana de ptfe-e em ratas ovariectomizadas. Estudo histológico e histomorfométrico

Abstract : The objective of this study was to evaluate quantitatively and to describe qualitatively the process of bone repair in the interface of receptor bed and graft autogenous bone block with or without a e-PTFE membrane, in osteopenia induced rats. To this end, we used forty-eight Wistar rats weighing about 300g, in which, with the aid of 4.1 mm trephine a graft was removed from the parietal bone and fixed to the surface of the left mandibular ramus. The animals were randomly divided into four experimental groups: Group 1 (n=12): SHAM operated and autogenous bone graft only; Group 2 (n=12): SHAM and autogenous bone graft covered by e-PTFE membrane; Group 3 (n=12): ovariectomized rats (OVX) and autogenous bone graft only; Group 4 (n=12): OVX and autogenous bone graft covered by e-PTFE membrane. The animals in each group were sacrificed at three time periods: 21, 45 and 60 days, each time with 4 animals per group. The specimens were decalcified and included, the sections were stained with HE and subjected to histological and histomorphometric analysis in light microscopy. The results of the ANOVA showed that the variables on the condition (OVZ and SHAM), and the time (21, 45 and 60 days) were statistically significant, and can be established with the Tukey test (5%) that the period 21-day differs significantly from the periods of 45 and 60 days, which did not differ among themselves. The descriptive histological analysis showed integration of the graft in all animals. It was concluded that the initial integration of the graft bed was negatively affected in the presence of induced osteopenia, and that the use or not of a e-PTFE membrane did not interfere in the process of integrationO objetivo deste estudo foi avaliar quantitativamente e descrever qualitativamente o processo de reparação óssea da interface leito receptor e enxerto ósseo autógeno em bloco associado ou não a membrana de PTFE-e, em ratas fêmeas, portadores de osteopenia induzida. Para tanto, foram utilizadas quarenta e oito ratas Wistar pesando aproximadamente 300g, nas quais, com o auxílio de uma trefina de 4,1mm de diâmetro retirou-se um fragmento ósseo do osso parietal o qual foi fixado à parede lateral do ramo mandibular esquerdo. Os animais foram divididos aleatoriamente em quatro grupos experimentais: Grupo 1 (n=12): ovariectomia simulada (SHAM) e realização de enxerto ósseo autógeno; Grupo 2 (n=12): SHAM e realização de enxerto ósseo autógeno em bloco com recobrimento por membrana de PTFE-e; Grupo 3 (n=12): ovariectomia (OVZ) e realização de enxerto ósseo autógeno em bloco; Grupo 4 (n=12): OVZ e realização de enxerto ósseo autógeno em bloco com recobrimento por membrana de PTFE-e. Os animais de cada grupo foram sacrificados em três períodos: 21, 45 e 60 dias, sendo cada período com 4 animais por grupo. As peças foram descalcificadas e incluídas; os cortes corados com HE e submetidos à análise histológica e histomorfométrica em microscopia de luz. Os resultados obtidos com os testes ANOVA mostraram que as variáveis referente a condição (OVZ e SHAM) e ao período (21,45 e 60 dias) foram estatisticamente significantes, e pode-se estabelecer com o teste de Tukey (5%) que o período de 21 dias difere estatisticamente dos períodos de 45 e 60 dias, que entre si não diferem. A análise histológica descritiva mostrou integração do enxerto em todos os animais. Concluímos que o processo inicial de integração do enxerto ao leito foi negativamente afetado na presença de osteopenia induzida e que o uso ou não da membrana de PTFE-e, não interferiu neste processo de integraçã