Osteoprotective effect by interleukin-4 (IL-4) on lipoprotein-induced periodontitis.

Lipoproteins are immunostimulatory bacterial components suggested to participate in inflammation-induced bone loss in periodontal disease through stimulation of osteoclast differentiation. Toll-like receptor 2 activation by Pam2CSK4 (PAM2), known to mimic bacterial lipoproteins, was previously shown to enhance periodontal bone resorption in mice. The anti-inflammatory cytokine interleukin-4 (IL-4) is a known inhibitor of RANKL-induced bone resorption in vitro. Here, we have investigated whether IL-4 could decrease PAM2-induced periodontal bone loss and osteoclastogenesis in vivo. In a model of periodontitis induced by gingival injections of PAM2 in mice, concomitant injections of IL-4 reduced bone loss. Histologically, IL-4 reduced the recruitment of inflammatory cells and the formation of TRAP+ osteoclasts stimulated by PAM2. Mouse bone marrow macrophages (BMMs) and neonatal calvarial osteoblasts were used to assess the effect of IL-4 on PAM2-induced osteoclastogenesis in vitro. In RANKL-primed BMMs stimulated by PAM2 Nfatc1, Ctsk, and Acp5 gene expression was up-regulated and resulted in robust formation of TRAP+ multinucleated osteoclasts, effects which were impaired by IL-4. These effects were mediated by impairment in PAM2-induced c-fos expression. In primary calvarial osteoblast cultures, IL-4 decreased PAM2-induced Tnfsf11 (encoding RANKL) mRNA and enhanced Tnfrsf11b (encoding OPG) expression. Our data demonstrate that the osteoprotective effect by IL-4 on lipoprotein-induced periodontal disease occurs through the inhibition of osteoclastogenesis by three mechanisms, one by acting directly on osteoclast progenitors, another by acting indirectly through decreasing the expression of osteoclast-regulating cytokines in osteoblasts and a third by decreasing inflammation.

Impact of soft tissue graft on the preservation of compromised sockets / Impacto do enxerto de tecido mole na preservação de alvéolos comprometidos

ABSTRACT The aim of this pilot study was to evaluate the impact of the association of free gingival graft (FGG) or collagen-matrix xenograft (CMX) to deproteinized bovine bone graft (DBBG) on the preservation of post-extraction sockets with facial-wall defects. Sixteen patients who presented a maxillary tooth with a facial bone defect and indication of extraction were selected. After the surgical procedure, all the post-extraction sockets were filled with DBBG and covered with a collagen membrane. The cervical part of the socket was then sealed with either FGG or CMX. Clinical and tomographic analyses were performed at baseline and 4 months after the grafting procedure. The FGG sockets showed higher values for the width of the bone ridge than the CMX sockets at 4 months. There was no difference regarding biopsy composition. In conclusion, regardless of the type of soft tissue graft used, socket preservation with DBBG at sites presenting facial bone defects enabled implant placement without further guided bone regeneration, whether the sockets were sealed with FGG or CMX.

RESUMO

Influence of residual bone height and sinus width on the outcome of maxillary sinus bone augmentation using anorganic bovine bone.

OBJECTIVE: To evaluate the influence of the posterior residual bone height and sinus width on the outcome of maxillary sinus bone augmentation using anorganic bovine bone. MATERIAL AND METHODS: Bilateral sinus bone augmentation was performed using anorganic bovine bone in 20 patients with residual bone height <2 mm in at least one site on each side. Trephine samples were removed at the implant insertion site 8 months after the grafting procedure, and histological and histomorphometric analyses were performed to examine the relative amount (%) of new bone, anorganic bovine bone, and soft tissue in the grafted area. Based on cone beam computed tomography evaluation, the sites of implant insertion were classified according to sinus width into narrow, average, and wide, and according to residual bone height into ≤2 and >2 mm. RESULTS: A total of 146 implants were installed and 103 biopsies were evaluated. New bone formation in sites classified as narrow (69 sites), average (19 sites), and wide (15 sites) was 28.5% ± 9.24, 28.9% ± 8.61, and 30.3% ± 7.80, respectively. The mean posterior maxillary residual bone height was 4.0 ± 2.43 mm, and 26 and 77 sites were classified as ≤2 and >2 mm, respectively. New bone formation was 26.2% ± 9.10 and 29.8% ± 8.67 for residual bone height ≤2 and >2 mm, respectively. The differences were non-significant. CONCLUSIONS: Within the limitations of the present study, posterior residual bone height and sinus width were not factors with influence on new bone formation in sinuses grafted exclusively with anorganic bovine bone after 8 months of healing.

Effect of low-level laser therapy on the healing of sites grafted with coagulum, deproteinized bovine bone, and biphasic ceramic made of hydroxyapatite and ß-tricalcium phosphate. In vivo study in rats.

OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the healing of biomaterial graft areas (i.e., coagulum, deproteinized bovine bone, and biphasic ceramics comprising hydroxyapatite and ß-tricalcium phosphate). MATERIAL AND METHODS: Ninety rats were divided into two groups according to laser irradiation use (λ 808 nm, 100 mW, φ ∼600 µm, seven sessions with 28 J of irradiation dose in total): a laser group and a control group. Each of these groups was divided into three subgroups of 15 animals each according to the type of biomaterial used: Coagulum (COA), deproteinized bovine bone (DBB), and hydroxyapatite/ß-tricalcium phosphate (HA/ßTCP). Biomaterials were inserted into Teflon domes, and these domes were grafted to the lateral aspect of the mandibular branch of the rats. The animals were sacrificed after 30, 60, and 90 days. Scarring patterns were evaluated by microtomography and histometry. The expression levels of BMP2, osteocalcin (OCN), and alkaline phosphatase (ALP) were evaluated by immunohistochemistry. The mRNA expression levels of ALP, BMP2, Jagged1, Osterix, Runx2, and TGFß1 were determined by RT-qPCR. RESULTS: The animals treated with LLLT exhibited increased mineralized tissues and bone, particularly after 90 days. These increases were associated with increased BMP2, OCN, and ALP protein expression and ALP, BMP2, and Jagged1 mRNA expression. CONCLUSION: LLLT improved the osteoconductive potential of DBB and HA/ßTCP grafts and bone formation in ungrafted areas. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Biopolymer-based membranes associated with osteogenic growth peptide for guided bone regeneration.

Barrier membranes for guided bone regeneration (GBR) mainly promote mechanical maintenance of bone defect space and induce osteopromotion. Additionally, biopolymer-based membranes may provide greater bioactivity and biocompatibility due to their similarity to extracellular matrix (ECM). In this study, biopolymers-based membranes from bacterial cellulose (BC) and collagen (COL) associated with osteogenic growth peptide (OGP(10-14)) were evaluated to determine in vitro osteoinductive potential in early osteogenesis; moreover, histological study was performed to evaluate the BC-COL OGP(10-14) membranes on bone healing after GBR in noncritical defects in rat femur. The results showed that the BC-COL and BC-COL OGP(10-14) membranes promoted cell proliferation and alkaline phosphatase activity in osteoblastic cell cultures. However, ECM mineralization was similar between cultures grown on BC OGP(10-14) and BC-COL OGP(10-14) membranes. In vivo results showed that all the membranes tested, including the peptide-free BC membrane, promoted better bone regeneration than control group. Furthermore, the BC-COL OGP(10-14) membranes induced higher radiographic density in the repaired bone than the other groups at 1, 4 and 16 weeks. Histomorphometric analyses revealed that the BC-COL OGP(10-14) induced higher percentage of bone tissue in the repaired area at 2 and 4 weeks than others membranes. In general, these biopolymer-based membranes might be potential candidates for bone regeneration applications.

Bacterial cellulose-hydroxyapatite composites with osteogenic growth peptide (OGP) or pentapeptide OGP on bone regeneration in critical-size calvarial defect model.

This study aimed to evaluate the potential of bacterial cellulose-hydroxyapatite (BC-HA) composites associated with osteogenic growth peptide (OGP) or pentapeptide OGP(10-14) in bone regeneration in critical-size calvarial defects in mice. In this study, the BC-HA, BC-HA-OGP, and BC-HA-OGP(10-14) membranes were analyzed at 3, 7, 15, 30, 60, and 90 days. In each period, the specimens were evaluated by micro-computed tomography (µCT), descriptive histology, gene expression of bone biomarkers by qPCR and VEGFR-2 (vascular endothelial growth factor) quantification by ELISA. Three days post-operative, Runx2, Tnfrsf11b and Bglap bone biomarkers were upregulated mainly by BC-HA OGP and BC-HA OGP(10-14) membranes, suggesting an acceleration of the osteoblast differentiation/activity with the use of these biomaterials. At 60 and 90 days, a high percentage of bone formation was observed by µCT for BC-HA and BC-HA OGP(10-14) membranes. High expression of some bone biomarkers, such as Alpl, Spp1, and Tnfrsf11b, was also observed for the same membranes on days 60 and 90. In conclusion, the BC-HA membrane promoted a better bone formation in critical-size mice calvarial defects. Nevertheless, incorporation of the peptides at the concentration of 10(-9) mol L(-1) did not improve bone regeneration potential in the long-term.

Treatment of atrophic mandibular fracture related to implant placement in an oral bisphosphonate user: a case report / Tratamento de fratura em mandíbula atrófica com implantes em paciente usuário de bisfosfonato: umrelato de caso

Objectives: Atrophic mandibular fractures associated with placement of dental implants is an uncommon condition and to best of our knowledge this event in an oral bisphosphonate user was never described before. Case report: A 74-years-old woman presented a submandibular hematoma and mobility between two fragments on the right side of the body of the mandible after four implants placement. The patient reported the use of oralbisphosphonates for three years for treatment of osteoporosis. A titanium plate was placed at the base of the mandible to fix the fracture and the patient underwent a hyperbaric oxygen therapy for three months. Nine months after the surgery, the patient had no further complications and rehabilitation treatment was completed. Conclusions: The fracture fixation was effective in the treatment of atrophic mandibular fractures in an oral bisphosphonate user, with no occurrence of complications like osteonecrosis.In addition, the oral rehabilitation with prosthesisunder the remaining implants showed a satisfactory outcome.

Objetivo: Fraturas de mandíbula atrófica associadas à inserção de implantes é uma condição de ocorrência incomum e o objetivo desse relato de caso é descrever o tratamento de fratura de mandíbula atrófica associada à instalação de implantes em uma paciente usuária de bisfosfonato oral. Relato de caso: Paciente do sexo feminino com 74 anos apresentava presença de um hematoma submandibular e mobilidade entre dois fragmentos no corpo da mandíbula no lado direito após a instalação de 4 implantes. A paciente reportou uso de bisfosfonato por via oral a 3 anos para tratamento de osteoporose. A fratura foi reduzida e fixadacom uma placa de titânio na base da mandíbula e a paciente foi submetida a sessões de câmara hiperbárica por 3 meses. Após 9 meses do procedimento cirúrgico a paciente não apresentou complicações adicionais e o tratamento reabilitador foi finalizado. Conclusão: A fixação foi efetiva no tratamento da fratura em mandíbula atrófica em um paciente usuário de bisfosfonato oral e complicações com osteonecrose não foram detectadas. Adicionalmente, a reabilitação oral com próteses sobre implantes remanescente apresentaram um resultado satisfatório.

Effects of the long-term administration of alendronate on the mechanical properties of the basal bone and on osseointegration.

OBJECTIVE: To evaluate the effect of the long-term administration of alendronate on the mechanical properties of the basal bone and on osseointegration. MATERIAL AND METHODS: One hundred and sixty female rats were randomly allocated into two equally sized groups: the control (CTL) group, which received the subcutaneous administration of saline solution, and the alendronate (ALD) group, which received the subcutaneous administration of alendronate (1 mg/kg/week). After 120 days of these therapies, one implant was placed in each rat tibia. Ten animals in each group were euthanized at 5, 10, 15, 20, 25, 30, 45, or 60 days after surgery. The tibias with implants evaluated regarding the removal torque, bone-implant contact (BIC), the bone area fraction occupancy (BAFO), and Ca/P ratio. The femurs were evaluated regarding bone mineral density (BMD) and using mechanical tests to evaluate the maximal force of fracture, stiffness, and tenacity. RESULTS: The ALD group presented statistically significant higher BMD (all periods except 15 days), maximal force of fracture (at 20, 30, and 45 days), tenacity (at 10, 20, 30, and 45 days), stiffness (45 days), removal torque (at 20, 25 and 30 days), BIC (at 20 and 60 days), and BAFO (at 20, 30, and 45 days) than the CTL group. No differences were found between the groups regarding the Ca/P ratio. CONCLUSION: Previous long-term therapy with alendronate caused an increase in the BMD, maximal force of fracture of the bone without changing the inorganic composition and elastic deformability of this tissue. Furthermore, the ALD therapy enhanced osseointegration.

Efeito do stress no grau de inflamação gengival em adolescentes grávidas: estudo piloto / Effect of stress on the degree ofgingival inflammation in pregnant adolescents: pilot study

Objetivo: Avaliar a severidade de inflamação gengival perante duas condições, estresse e gravidez, em um grupo de adolescentes atendidas no serviço público de saúde na cidade de Maceió-AL. Material e métodos: 80 adolescentes grávidas com faixa etária ente 14 e 19 anos, atendidas em centros de referência ao atendimento pré-natal na cidade de Maceió-AL, participaram desse estudo piloto. O estresse social foi avaliado subjetivamente pelo teste de avaliação de estresse e a inflamação gengival foi avaliada pelo índice de inflamação gengival através de um exame clínico utilizando-se 6 dentes índices. A análise estatística foi executada relacionando o estresse social com dados demográficos e de hábitos de higiene oral e com relação a inflamação gengival pelo teste de Mann-Whitney e pelo teste de Fischer para variáveis dicotômicas. Resultados: Na avaliação da relação do estresse com a inflamação gengival e com o índice de placa com controle das variáveis independentes foi utilizada a regressão logística multivariada. Todos os testes foram aplicados com nível de confiança de 95%. O teste de Mann-Whitney demonstrou que as grávidas estressadas apresentavam maior frequência de escovação que as grávidas sem stress (p=0.008). Os outros dados demográficos e de hábitos de higiene oral se distribuíram igualmente entre os grupos. A análise por regressão logística multivariada demonstrou que nenhuma das variáveis independentes influenciou no índice gengival e no índice de placa em mulheres grávidas com ou sem stress. Conclusão: O estresse não causou aumento da severidade da inflamação gengival em adolescentes grávidas.

Objective: Evaluate the severity of gingival inflammation against two conditions, stress and pregnancy, in a group of adolescents treated at a public health service in Maceió-AL. Material and methods: 80 pregnant adolescents aged between 14 to 19 years being treated at referral centers for prenatal care in the city of Maceió-AL, participated in this pilot study. The social stress was subjectively evaluated by assessment of stress test (Lipp test) and gingival inflammation was assessed by the index of gingival inflammation (Loe & Silness) through a clinical examination using six index teeth. Statistical analysis was performed relating the social stress with demographic data and habits regarding oral hygiene and gingival inflammation using the Mann-Whitney and Fischer's test for dichotomous variables. Results: When considering the influence of the stress in gingival inflammation and plaque index with controlled of theindependent variables the multivariate logistic regression was used. All tests were applied with a confidence level of 95%. The Mann-Whitney test demonstrated that pregnant women under stress showed higher frequency of brushing than pregnant women without stress (p = 0.008). The other demographic and oral hygiene habits were equally distributed between the groups. A multivariate logistic regression analysis showed that none of the independent variables influenced the gingival index and plaque index in pregnant women with or without stress. Conclusion:The stress did not increase the severity of gingival inflammation in pregnant adolescents.

Efeito da aplicação de adesivos de 2 passos e autocondicionantes fotoativados por luz halógena ou LED na microinfiltração marginal: estudo in vitro. / Effect of 2-step/self-each bond system and halogen light or LED on the microleakage: in vitro study.

O objetivo desse estudo foi analisar a efetividade de sistemas adesivos convencionais e autocondicionantes, e de diferentes métodos de fotoativação para redução da microinfiltração marginal. Foram utilizados 48 dentes incisivos bovinos nesse estudo. Os dentes foram divididos em quatro grupos de 12 amostras de acordo com o tipo de adesivo ou método de fotoativação utilizado: Grupo 1- Sistema adesivo de passos fotoativadas por luz halógena com intensidade de 700 mW/cm2 Grupo 2 - Sistema adesivo de dois passos fotoativados pelo LED com intensidade de 470 mW/cm2; Grupo 3 - sistema adesivo autocondicionante fotoativados por luz halógena; Grupo 4 - Sistema adesivo autocondicionante fotoativados por LED. Uma resina composta nanoparticulada foi utilizada para restaurar todas as cavidades. Em seguida, os grupos foram submetidos ao tratamento de ciclagem térmica e foram colocados por 24 horas em solução de azul de metileno. A microinfiltração foi avaliada de acordo com o grau de penetração do corante na interface dente-restauração. Para análise estatística, foi utilizado o teste não paramétrico de Kruskal Wallis complementado pelo teste de Mann-Whitney, no nível de 5% de significância. O grupo 1 apresentou estatisticamente menores índices de microinfiltração marginal que o grupo 2 na parece oclusal (p<0.05) e os grupos 1 e 4 apresentaram menores graus de microinfiltração marginal que o grupo 2 na parede cervical(p<0.05). A aplicação do sistema adesivo de dois passos associado a polimerização com luz halógena promoveram os menores graus de microinfiltração marginal.

The aim of this research was to analyze the effectiveness of conventional and self-etching bonding systems and different curing methods for reduction of marginal microleakage. 48 bovine incisor teeth were used in this study. The teeth were divided into four groups of 12 samples according to the type of adhesive system or curing method used: Group 1- Two-step bonding system photoactivated by halogen light with intensity of 700 mW/cm2; Group 2- Two-step bonding system photoactivated by LED with 470 mW/ cm2 of intensity; Group 3 - Self etch bonding system photoactivated by halogen light; Group 4- Self etch bonding system photoactivated by LED. A nanofilled composite resin was used to restore all the cavities. Then the groups were subjected to thermal cycling treatment and were placed for 24 hours in a methylene blue solution. The microleakage was assessed according to the degree ofpenetration of the colorant in tooth-restoration interface. For statistical analysis, the non-parametric Kruskal Wallis test complemented by Mann-Whitney were used with 5 % level of significance. The Group 1 showed lower marginal microleakage than Group 2 on occlusal wall (p<0.05). Adittionally, appears and the groups 1 and 4 had smaller degrees of marginal microleakage that the cervical wall 2 Group (p<0.05). The application of two-step bonding system associated with the polymerization by halogen light promoted the lowest degrees of marginal microleakage.