An oxygen-releasing agent promotes healing of skin wounds in rats.

OBJECTIVE: To evaluate the local effect of a slow oxygen-release gel on the healing of standardised skin wounds caused in rats. METHOD: Skin wounds were created on the backs of male rats (Rattus norvegicus, Wistar) that were randomly allocated into two groups. In the treated (T) and control (C) groups, oxygen gel and distilled water, respectively, were applied to the wounds on alternate days for 28 days. Postoperatively, euthanasia was performed at 5, 10, 14, 21 and 28 days, followed by clinical, histological (Masson's trichrome) and immunohistochemical analysis. Data were subjected to analysis of variance (ANOVA) and Bonferroni's test. RESULTS: The cohort comprised 50 rats. On clinical and histological analysis, groups C and T showed similar characteristics 5 days post-operation. Subsequently, group T showed better healing at 14, 21 and 28 days and presented more intense inflammatory infiltrate up to 10 days. At days 14, 21 and 28, group T exhibited a reduction in oedema and increased angiogenesis, granulation tissue formation, and deposition of collagen fibres than group C. Immunohistochemical analysis showed the presence of tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) in both the groups, but the levels were significantly higher in group T (p<0.05). CONCLUSION: The local application of slow oxygen-release gel accelerated the healing of standardised skin wounds created surgically in rats, with increased angiogenesis and better collagen fibre formation.

Vertical Bonegraft Wrap-A Technique to Increase Soft Tissue Volume in Paranasal Region.

This study presents a technique to gain soft tissue volume in the paranasal region, using a xenogenous bonegraft wrap with a porcine pericardium collagen membrane in a patient with severe paranasal deficiency and midfacial hypoplasia. The technique consisted of using particulate bonegraft that is wrapped on collagen membrane and placed vertically and parallel to the lateral wall of the nasal cavity, over maxillary osteotomies. In a tomographic analysis of linear and volumetric measurements with 14 days and 6 months after the procedure, it was observed good stability of the vertical bonegraft wrap, as well as volume gain in the paranasal region and low absorption rate of the grafted material. This technique presented a satisfactory clinical result, promoting an improvement in facial harmony with gain volume in the paranasal region, guaranteeing greater predictability in the treatment of a patient with significant maxillary advancement surgery.

Microbial evaluation of implant surface - a clinical study comparing submerged, non-submerged and immediately loaded implants

Aim: The aim of the present study was to evaluate the microbial contamination in internal and external walls of cone morse implant walls. Methods: Eleven patients with edentulous mandibular posterior area were selected to received dental implants, divided into groups: submerged (S), non-submerged (NS), and immediately loaded (IL). Microbiological evaluations (microorganisms' number, aerobic and anaerobic colony forming units (CFU) number and microorganisms' qualification) were divided into internal and external collection of the implant walls, at different stages: T0 (surgical procedure), T2 (suture removal), T4 (reopening S group), T6 (suture removal S group), and T8 (abutment placement in S and NS). All data were submitted to statistical analyses, with confidence level of 0.05. Results: There was difference in number of microorganisms observed over time within the same group (p < 0.05). A difference was observed in CFU when evaluated within the same group over time (p < 0.05), except for the IL group. In internal collection, a predominance of non-formation of microorganisms was observed at T0 in all groups, while formation of Gram-positive Diplococci and Gram-positive Bacilli was observed at T8 (p>0.05). In external collection, an increase in number of microorganisms was observed at T0. Conclusion: There was no difference in microbial contamination among the evaluated groups. The microorganism's colonization changed over time

Effects of local single dose administration of parathormone on the early stages of osseointegration: A pre-clinical study.

The present study aimed to evaluate the effect of parathormone (PTH) administered directly to the implant's surface prior to insertion, using a large translational animal model. Sixty titanium implants were divided into four groups: (i) Collagen, control group, where implants were coated with Type-I Bovine-collagen, and three experimental groups, where implants received varying doses of PTH: (ii) 12.5, (iii) 25, and (iv) 50 µg, prior to placement. Fifteen female sheep (~2 years old, weighing ~65 kg) received four implants in an interpolated fashion in C3, C4 or C5 vertebral bodies. After 3-, 6- and 12-weeks, samples were harvested, histologically processed, qualitatively and quantitatively assessed for bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). BIC yielded lower values at 6-weeks for 50 µg relative to the control group, with no significant differences, when compared to the 12.5- and 25-µg. No significant differences were detected at 6-weeks between collagen, 12.5- and 25-µg groups. At 3- and 12-weeks, no differences were detected for BIC among PTH groups. With respect to BAFO, no significant differences were observed between the control and experimental groups independent of PTH concentration and time in vivo. Qualitative observations at 3-weeks indicated the presence of a more mature bone near the implant's surface with the application of PTH, however, no significant differences in new bone formation or healing patterns were observed at 6- and 12-weeks. Single local application of different concentrations of PTH on titanium implant's surface did not influence the osseointegration at any time-point evaluation in low-density bone.

Single nucleotide polymorphisms in dopamine receptor D2 are associated with bruxism and its circadian phenotypes in children.

Objective: To evaluate the association of bruxism phenotypes with single nucleotide polymorphisms in FKBP5, DRD2, ANKK1, and COMT.Methods: Clinical oral examination was performed to diagnose bruxism phenotypes in 150 children. DNA was collected from saliva. Logistic univariate regression, Chi-square, and Fisher's exact tests were performed (p < 0.05).Results: Bruxism was associated with DRD2 (p = 0.02). Tooth grinding while awake was associated with ANKK1 (p < 0.001), and tooth grinding while asleep was associated with DRD2 in the additive (p = 0.030) and dominant (p = 0.008) model. Tooth clenching while awake was associated with ANKK1 in the additive (p = 0.005) and dominant (p = 0.008) models, whereas tooth clenching while asleep was associated with ANKK1 (p < 0.001) and with COMT in the additive (p = 0.001) and dominant (p = 0.003) models.Discussion: Polymorphisms in DRD2, ANKK1, and COMT are associated with bruxism phenotypes.

Effect of Age and Sodium Alendronate on Femoral Fracture Repair: Biochemical and Biomechanical Study in Rats.

BACKGROUND: Bisphosphonates are drugs widely used to reduce bone resorption, increase bone mineral density and control age-related bone loss. Although there are studies reporting differences in bone structure between young and old adults, it is still difficult to predict changes related to bone aging. The aim of this study was to evaluate the effect of age and sodium alendronate on bone repair of femoral fractures in rats. METHODS: Wistar rats (n = 40) were allocated into groups: O (control old-rats), Y (control young-rats), OA (alendronate old-rats) and YA (alendronate young-rats). All animals underwent linear fracture surgery followed by fixation. Groups OA and YA received 1 mg/kg alendronate three times a week until euthanasia. Biochemical analysis of calcium and alkaline phosphatase was done. After euthanasia, femurs were evaluated in relation to cross-section and flexural strength, with three-point bending test. Data were submitted to statistical analysis with significance level of 0.05. RESULTS: There was no difference in calcium and alkaline phosphatase levels (p > 0.05). Young animals presented lower cross-section than older animals (p < 0.05). Only fractured side, young animals presented major flexural strength than older animals (p < 0.05). There was no difference between the animals that used or not alendronate in relation to cross-section and flexural strength (p > 0.05). When compared fractured and non-fractured femurs, major cross-section on fractured side was observed (p < 0.05). Flexural strength presented higher values in femurs on non-fractured side (p < 0.05). There was correlation of weight and cross-section (R = +0.91) and weight with flexural strength of fractured and non-fractured side, respectively (R = -0.97 and -0.71). CONCLUSION: In short, there was no difference of calcium and alkaline phosphatase during the bone repair process. Age has influence in cross-section and flexural strength. Alendronate showed no association with these factors.

Growth hormone effects on healing efficacy, bone resorption and renal morphology of rats: histological and histometric study in rat calvaria.

Previous reports demonstrated the utility of systemic application of growth hormone (GH) in the treatment of bone defects. Very few studies correlated bone repair efficacy with hepatic and renal side effects promoted by locally-delivered GH. The objectives of this study were to assess the bone repair properties along with hepatic and renal adverse effects promoted by local application of GH in a rat model. Thirty-two rats were randomly divided (4 groups; n = 8/group), as follows: (i) AB (autogenous bone + local application of saline solution [SS]), (ii) AB+ (autogenous bone + SS local application + SS irrigation), (iii) AB/GH+ (autogenous bone + SS local application + GH irrigation) and (iv) AB/GHL+ (autogenous bone + GH local application + GH irrigation). Critical-sized defects (diameter = 5.0 mm) were surgically created by a single operator in the calvaria of rats. Defects were filled with ground autogenous bone. Defects pertaining to AB+ and AB/GH+ received a mixture of autogenous bone and a SS-saturated (0.02 mL) collagen sponge covered with bovine cortical membrane. Defects in group AB/GHL+, were filled with the same biomaterials saturated with GH (0.02 mL). SS (0.1 mL) or GH (0.1 mL, equivalent to 0.4 IU) were applied locally on alternate days (8 weeks) in animals in groups AB, AB+ and AB/GH+ or AB/GHL+, respectively. Bone repair properties was determined in hematoxylin/eosin-stained slices using traditional histologic and histomorphometric techniques along with optical microscopy and digital image analysis. Statistical differences among groups was determined using Kruskal-Wallis and Tukey post hoc tests (α = 0.05). Histology results indicated that AB and AB+ displayed greater presence of autogenous bone as compared to AB/GH+ and AB/GHL+. Histomorphometric results indicated significantly higher osteoid matrix formation in AB and AB+ when compared to AB/GHL+ (p = 0.009). Kidneys and livers were found to have their glomeruli preserved in AB and AB+. Strong glomeruli necrosis and large areas of protein deposition were found in AB/GH+. Abnormal small-sized glomeruli were found in AB/GHL+. The utilization of autogenous bone graft associated with local application and irrigation with GH was shown to not improve the bone repair in calvarial critical-sized defects in a rat model.

The Role of Marine Organic Extract in Bone Regeneration: A Pilot Study.

Novel biomaterials capable of accelerating the healing process of skeletal tissues are urgently needed in dentistry. The present in vivo study assessed the osteoconductive and osteoinductive properties of experimental biphasic bioceramics (HA-TCP) modified or not by a nacre extract (marine organic extract, MOE) in a sheep model. Fabrication of MOE involved mixing ground nacre (0.05 g, particle sizes < 0.1 mm) with glacial ethanoic acid (5 mL, pH 7) for 72 hours using external magnetic stirring (25°C). Nonreactive carriers (sterile polythene tubes; 3/animal, radius: 2.5 mm, length: 10.0 mm) pertaining to the control (empty) or experimental groups (HA-TCP or MOE-modified HA-TCP) were implanted intramuscularly into the abdominal segment of the torso in sheep (n = 8, age: 2 years, weight: 45 kg). Euthanization of animals was performed at 3 and 6 months after surgery. Tissues harvested were subjected to macroscopic and radiographic assessments. Specimens were then stained for histological analysis. Both control and experimental animals were capable of inducing the neoformation of fibrous connective tissue at both time points where superior amounts of tissue formation and mineralization were detected for experimental groups (unaltered (at 3 and 6 mos) and MOE-modified HA-TCP (at 3 mos)). Histological results, however, revealed that mature bone formation was only observed for specimens fabricated with MOE-modified HA-TCP in a time-dependent manner. The present study has successfully demonstrated the in vivo utility of experimental biphasic bioceramics modified by MOE in an ectopic grafting sheep model. Promising osteoconductive and osteoinductive properties must be further developed and confirmed by subsequent research.

Osteoconductivity of Biphasic Calcium Phosphate Ceramic Improves New Bone Formation: A Histologic, Histomorphometric, Gene Expression, and Microcomputed Tomography Study.

PURPOSE: The purpose of this study was to evaluate bone repair with two bone substitutes, deproteinized bovine bone and biphasic calcium phosphate ceramics, associated with autogenous bone. MATERIALS AND METHODS: The experimental groups were as follows: autogenous bone only (AB), autogenous bone/deproteinized bovine bone (1:1), and autogenous bone/biphasic calcium phosphate ceramic (1:1). After 30, 60, and 90 days, animals were euthanized and samples were collected for microcomputed tomography (micro-CT), histologic, histomorphometric, and expression analyses of VEGFA, RUNX2, ALP, COL1A1, OCN, PHEX, RANKL, and OPG genes by real-time polymerase chain reaction (PCR) array. RESULTS: Histomorphometric analysis showed no difference in the amount of immature bone between AB and AB/biphasic calcium phosphate ceramic at 30 and 60 days. There was less mature bone formation in the AB/deproteinized bovine bone at 60 days compared with AB/biphasic calcium phosphate ceramic and AB, and a lower amount of immature bone in the AB/deproteinized bovine bone at 30 and 60 days compared with the AB (P ≤ .05). Micro-CT analysis showed higher immature bone volume (BVI) in the AB/biphasic calcium phosphate ceramic at 60 days and lower BVI at 90 days (P ≤ .05). Molecular analysis showed a lower expression of all genes in the AB/deproteinized bovine bone and AB/biphasic calcium phosphate ceramic compared with AB at all time points. A greater expression of RANKL was found in the AB/deproteinized bovine bone compared with AB/biphasic calcium phosphate ceramic at 30 days (P ≤ .05), and a lower expression of the OC, RUNX2, and ALP genes in AB/deproteinized bovine bone and AB/biphasic calcium phosphate ceramic was found compared with AB at all time points (P ≤ .05). CONCLUSION: The use of biphasic calcium phosphate ceramic resulted in greater immature bone formation than deproteinized bovine bone at an early assessment. The studied bone regeneration genes were downregulated in comparison to the control.

Radiofrequency therapy in esthetic dermatology: A review of clinical evidences.

BACKGROUND: Chronological skin aging causes the modification of genetic material through enzymes and proteins changes. The process reduces cellular proliferation, along with loss of tissue elasticity, reduced ability to regulate aqueous exchanges, and inefficient tissue replication. Appearance is negatively affected by cumulative changes in coloration, texture, and elasticity over time. The increase in the population's average life expectancy boosts the search for cosmetic therapies that can delay aging, mostly for the noninvasive modalities. Among the various options, radiofrequency therapy is a technique that can help reduce the effects of skin aging. AIM: Therefore, this study aims to review clinical evidence provided by scientific literature on the benefits of using radiofrequency therapy in reducing skin aging effects. METHODS: A review of the literature concerning skin aging, characteristics of radiofrequency therapy, and radiofrequency therapy in the treatment of skin laxity and mechanism of action was conducted using PubMed. RESULTS: The included studies have suggested that the mechanism of radiofrequency action is heating the dermis while preserving the epidermis. This heating causes immediate collagen denaturation, which is followed by the formation of new collagen, naturally providing skin tightening and greater elasticity. CONCLUSION: Even when used as single therapeutic modality, radiofrequency seems to meet the expectations in reducing the effects of skin aging.

Genetic polymorphism in ESR2 and risk of tooth agenesis

Introduction: Tooth agenesis (TA) is the congenital absence of teeth. Several studies have proposed a strong genetic background for this condition. Aim: The present cross-sectional study aimed to evaluate whether genetic polymorphisms in the genes that code for estrogen receptors ( ESR1 and ESR2 ) are associated with the presence of isolated TA in a Brazilian sample. Methods: Panoramic radiographs of 142 orthodontic patients were assessed to determine TA of permanent teeth (excluding third molars). DNA of patients was extracted from buccal cells from saliva to evaluate genetic polymorphisms in ESR1 ( rs2234693 and rs9340799 ) and ESR2 ( rs1256049 and rs4986938 ) by genotyping using the real-time PCR technique. For statistical analyses, associations between the distributions of the alleles and genotypes, and the ocurrence of TA were assessed for each genetic polymorphism, with an established alpha of 5%. Results: Thirteen patients had at least 1 congenital missing tooth. The number of congenitally missing teeth ranged from 1 to 11. The genetic polymorphisms rs2234693 and rs9340799 in ESR1 and rs1256049 in ESR2 were not associated with TA ( p > 0.05) . For the genetic polymorphism rs4986938 in ESR2, the genotype and allele distributions were significantly different between the patients with and without TA ( p < 0.05). The CC genotype and the C allele were overrepresented in the TA patients. Conclusion: The genetic polymorphism rs4986938 in ESR2 was associated with the ocurrence o f TA.

Introdução: A agenesia dentária (AD) é a ausência congênita de um ou mais dentes. Vários estudos vêm sugerindo o forte componente genético para essa condição. Objetivo: O presente estudo teve como objetivo avaliar se os polimorfismos genéticos nos genes que codificam os receptores de estrógeno ( ESR1 e ESR2 ) estão associados à ocorrrência de AD isolada em uma amostra brasileira. Métodos: Radiografias panorâmicas de 142 pacientes ortodônticos foram avaliadas para determinar AD de dentes permanentes (excluindo terceiros molares). O DNA dos pacientes foi extraído das células da mucosa bucal contidas na saliva para avaliar polimorfismos genéticos em ESR1 ( rs2234693 e rs9340799 ) e ESR2 ( rs1256049 e rs4986938 ) por genotipagem usando a técnica de PCR em tempo real. Para análises estatísticas, associações entre as distribuições dos alelos e genótipos e a ocorrrência de AD foram avaliadas para cada polimorfismo genético, com um alfa estabelecido de 5%. Resultados: Treze pacientes tiveram pelo menos 1 dente congenitamente ausente. O número de dentes congenitamente ausentes variou de 1 a 11. Os polimorfismos genéticos rs2234693 e rs9340799 no ESR1 e rs1256049 no ESR2 não foram associados à AD ( p > 0,05). Para o polimorfismo genético rs4986938 no ESR2 , as distribuições dos genótipos e dos alelos foram estatisticamente diferentes entre os pacientes com e sem AD ( p < 0,05). O genótipo CC e o alelo C estavam super-representados nos pacientes com AD. Conclusão: Houve associação entre o polimorfismo genético rs4986938 no ESR2 e a ocorrrência de AD.

Bone repair in craniofacial defects treated with different doses of alendronate: a histological, histomorphometric, and immunohistochemical study.

OBJECTIVE: The objective of the study is to evaluate bone repair in rats treated with different alendronate doses. MATHERIALS AND METHODS: Sixty female rats ovariectomized were randomly divided in three groups: group C (control group), group A1 (ALN/1 mg/kg), and A2 (ALN/ 3 mg/kg). Each animal received subcutaneous applications of sodium alendronate at a dose correspondent to group A1 or A2 three times a week, while the control group received 0.9% saline solution. After 4 weeks of application, a critical defect was created in the calvaria of animals of all groups. The defect was filled by particulate autogenous bone. The applications were maintained until euthanasia, which occurred 15 and 60 days after the surgical procedure. The pieces were sent for histological, histomorphometric and immunohistochemical analysis. The data were submitted to statistical analysis with significance level of 0.05. RESULTS: The descriptive histological analysis demonstrated an increase in bone neoformation in both groups treated with alendronate when compared to the control group. The histomorphometric analysis showed an increase in the amount of neoformed bone in A1 and A2 groups when compared to group C, both at 15 days (p = 0.0002) and at 60 days (p = 0.001). In the immunohistochemical analysis, it was possible to observe a difference in immunolabeling just for Mmp2 at the time of 60 days in A1 (p = 0.001) and A2 (p = 0.023) when compared to the control group. CONCLUSION: Systemic delivery of alendronate, regardless of the dose, increased the amount of bone neoformation. CLINICAL RELEVANCE: Prescription of sodium alendronate at 1 mg/kg for improvement of bone neoformation in bone graft procedures.

Effect of Local Application of Alendronate and Parathyroid Hormone on Craniofacial Bone Repair - a Preliminary Study.

This study aimed to evaluate the effect of two methods of local application of alendronate and parathyroid hormone (PTH) on bone repair and the systemic implications. A critically sized defect (5 mm) was created in the cranial region of twenty-five male Wistar rats, and the bone removed was particulated, and grafted back to the defect with different treatments. The animals were randomly divided into five groups: A1- bone graft immersion in alendronate solution (3 mg/kg) for 5 minutes; P1- bone graft immersion in PTH solution (20 µg); A2- weekly local applications of alendronate 1 mg/kg; P2- weekly local applications of PTH (20 µg); C- no drugs were used. The animals were euthanized 60 days after surgery. Cranial bone blocks were removed for histological, histomorphometric, and immunohistochemical analyses. MMP-2 and MMP-9 were used for immunolabeling. The kidneys, liver, and brain were also removed from all the rats for histological analysis. The data were submitted for statistical analysis with a level of significance of 0.05 (One-way ANOVA). The group C and group P2 presented a higher quantity of viable bone particles than the remaining groups. Groups A1, A2, and P1 presented with fewer viable bone particles than the control group, with a predominance of non-mineralized connective tissue. The histomorphometric analysis revealed no differences in relative bone area or MMP-2 or MMP-9 immunolabeling between the groups (p>0.05). Group A2 showed presence of fat in the liver consistent with hepatic steatosis. Changes in brain tissue were observed in groups A1 and P1.

In vivo regeneration functionalities of experimental organo-biomaterials containing water-soluble nacre extract.

BACKGROUND: Novel multifunctional biomaterials were recently designed to allow for an optimized tissue regeneration process. PURPOSE: To comprehensively assess (photographic, radiographic and histological) the in vivo functionality of demineralized bovine bone matrix (DBM) associated with an experimental marine organic extract (MOE) from nacre in a sheep ectopic grafting model. MATERIALS AND METHODS: Synthesis of MOE was based on mixing powdered nacre (0.05 g, particles average size <0.1 mm) with acetic acid (5 mL, pH 7) under constant stirring for 72 hours (25 °C). Polyethylene tubes (3/animal, n = 4, diameter: 5.0 mm × length: 10.0 mm) from the control (empty) or experimental groups (DBM or DBM + MOE) were then intramuscularly implanted into the lumbar regions of sheep (n = 8, 2-years old, ≈45 kg). Animals were euthanized at 3 and 6 months to allow for the collection of tissue samples. Tissue samples were fixed in formalin 10% (buffered, 7 days) in preparation for photographic, radiographic and histological assessments. Acquired images were then analyzed using digital image analysis software to quantify the amount of neoformed tissues, whereas radiographic and histological analyses were performed to determine radiopacity and classification of tissues deposited inside of the tubes. RESULTS: Photographic and radiographic analyses have shown that both pure (unaltered) and MOE-modified DBM were capable of depositing neoformed tissues (at 3 and 6 months), where higher levels of deposition and radiopacity were observed on groups treated with experimental materials. Histological results, however, demonstrated that tissues formed from both unaltered and MOE-modified DBM were only fibrous connective in origin. CONCLUSIONS: As an ectopic grafting in sheep, the experimental organo-biomaterial association applied did not reveal any osteoinductive property but led to a fibrous tissue repair only.

Effect of local application of alendronate and parathyroid hormone on craniofacial bone repair - a preliminary study

Abstract This study aimed to evaluate the effect of two methods of local application of alendronate and parathyroid hormone (PTH) on bone repair and the systemic implications. A critically sized defect (5 mm) was created in the cranial region of twenty-five male Wistar rats, and the bone removed was particulated, and grafted back to the defect with different treatments. The animals were randomly divided into five groups: A1- bone graft immersion in alendronate solution (3 mg/kg) for 5 minutes; P1- bone graft immersion in PTH solution (20 µg); A2- weekly local applications of alendronate 1 mg/kg; P2- weekly local applications of PTH (20 µg); C- no drugs were used. The animals were euthanized 60 days after surgery. Cranial bone blocks were removed for histological, histomorphometric, and immunohistochemical analyses. MMP-2 and MMP-9 were used for immunolabeling. The kidneys, liver, and brain were also removed from all the rats for histological analysis. The data were submitted for statistical analysis with a level of significance of 0.05 (One-way ANOVA). The group C and group P2 presented a higher quantity of viable bone particles than the remaining groups. Groups A1, A2, and P1 presented with fewer viable bone particles than the control group, with a predominance of non-mineralized connective tissue. The histomorphometric analysis revealed no differences in relative bone area or MMP-2 or MMP-9 immunolabeling between the groups (p>0.05). Group A2 showed presence of fat in the liver consistent with hepatic steatosis. Changes in brain tissue were observed in groups A1 and P1.

Resumo Este estudo visou avaliar o efeito de dois métodos de aplicação local de alendronato e de paratormônio (PTH) no reparo ósseo e avaliar as implicações sistêmicas. Um defeito de tamanho crítico (5 mm) foi criado na calota craniana de vinte e cinco ratos Wistar machos, e o osso removido foi particulado e enxertado de volta no defeito com diferentes tratamentos. Os animais foram divididos aleatoriamente em cinco grupos: A1: imersão do enxerto ósseo em solução de alendronato (3 mg/kg) durante 5 min; P1- imersão do osso em solução de PTH (20 μg); A2- aplicações locais semanais de alendronato 1 mg/kg; P2- aplicações locais semanais de PTH 20 μg; C: não foram utilizados medicamentos. Os animais foram eutanasiados 60 dias após a cirurgia. Foram removidos os blocos ósseos envolvendo a região do defeito para realização das análises histológica, histomorfométrica e imuno-histoquímica. MMP2 e MMP9 foram as imunomarcações utilizadas. Os rins, fígado e cérebro também foram removidos de todos os ratos para análise histológica. Os dados foram submetidos à análise estatística com um nível de significância de 0,05 (One-way ANOVA). A análise histológica revelou que o grupo C e o grupo P2 apresentaram maior quantidade de partículas ósseas viáveis do que as apresentadas pelos demais grupos. Os grupos A1, A2 e P1 apresentaram menos partículas ósseas viáveis em comparação com o grupo controle com predominância de tecido conjuntivo não mineralizado. A análise histomorfométrica não revelou diferenças entres os grupos na área óssea relativa ou em MMP2 e MMP9 (p>0,05). O grupo A2 mostrou presença de gordura no fígado consistente com esteatose hepática. Alterações no tecido cerebral foram observadas nos grupos A1 e P1.

Oral and masticatory rehabilitation using osseointegrated dental implants after resective treatment of multicystic ameloblastoma in the lower jaw with a fibula graft.

Ameloblastoma is an aggressive odontogenic tumor which typically occurs between third and fourth decade of life that often needs resective approach. Immediate reconstruction may show better results. The treatment of multicystic ameloblastoma in the mandible being a rare case that occurred in the late second decade of life, which was surgically removed along with the affected teeth with safety margins, and the region was immediately reconstructed using a vascularized graft, removed from the fibula. Its integration, in combination with osseointegrated dental implants and fixed implant-supported prostheses, restored chewing function and esthetics. After 6 years from fibular graft and 24 months of dental implants, an excellent outcome was observed, with oral health and normal functions properly restored, and the immediate reconstruction of the mandible in resective cases, associated with oral rehabilitation with dental implants, may be considered a suitable treatment option.

Prolonged use of alendronate alters the biology of cranial repair in estrogen-deficient rats' associated simultaneous immunohistochemical expression of TGF-ß1+, α-ER+, and BMPR1B.

OBJECTIVES: TGF-ß1 is a cytokine that may induce both osteoneogenesis through Runx-2 or fibrosis via the transcription of α-smooth muscle actin (α-SMA). Because it has been previously known that alendronate increases the level of TGF-ß1 and that under the usual condition of bone metabolism the estrogen may prevent the fibrotic effect of TGF-ß1, the aim of this study was to evaluate if alendronate alters the cellular differentiation process post calvarial surgery in estrogen-deficient specimens. MATERIALS AND METHODS: A transosseous defect that was 5 mm in diameter was created on the calvarium of each of 32 female rats with previous ovarian-salpingo-oophorectomy. All defects were treated with autografts, and 16 rats received the administration of 1 mg/kg of alendronate three times a week until euthanasia on the 15th and 60th day post surgery. Histomorphometric and immunohistochemical analyses of the expression of TGF-ß1, estrogen receptor alpha nuclear (α-ER), α-SMA, BMPR1B, and Runx-2 were performed, and ELISA was used to measure the level of estrogen. RESULTS: All animals demonstrated low levels of estrogen post ovarian-salpingo-oophorectomy. The histological results demonstrated larger bone matrix deposition in specimens treated with alendronate on the 15th day post surgery. The result was associated with a higher co-expression of TGF-ß1, BMPR1B, and Runx-2 when compared with the control group. In addition, on the 60th day post surgery, the increase of bone matrix deposition from 15th to 60th day was discrete in specimens treated with alendronate compared with the control group. This result coincided with the intense simultaneous expression of TGF-ß1, α-ER, and α-SMA, whereas the expression of BMPR1B and Runx-2 decreased. CONCLUSION: The prolonged administration of alendronate altered the cranial repair in ovarian-salpingo-oophorectomized specimens due to the simultaneous occurrence of low estrogen and the presence of TGF-ß1+/α-ER+ inducing the presence of α-SMA+, whereas BMPR1B and Runx-2 were suppressed. CLINICAL RELEVANCE: The prolonged administration of alendronate alters osteoneogenesis and induces an unusual microenvironment in the bone that seems to imitate the physiological tissue damage that culminates in the loss of the functional layer of endometrium.

Effects of low-level laser therapy and platelet concentrate on bone repair: Histological, histomorphometric, immunohistochemical, and radiographic study.

PURPOSE: Low-level laser therapy (LLLT) can increase bone metabolism, cell proliferation, and maturation, and reduce inflammation, while platelet concentrate (PC) assists bone healing process by releasing proteins and growth factors. Here, we evaluated the efficacy of combined LLLT and PC therapy in the healing of critical-size bone defects. MATERIALS AND METHODS: Calvarial critical-size defects 5 mm in diameter were made in 48 Wistar rats. Bones were removed, milled, and used as autogenous bone grafts. Animals were randomized into four groups: LP (LLLT + PC), PC, L (LLLT), and C (control, autogenous graft only). Animals were sacrificed at day 30 and 60 post-surgery. Specimens were submitted to radiographic (digital and conventional), histological, histomorphometric, and immunohistochemical analyses. RESULTS: Digital radiography was shown to be a better image analysis method compared with conventional radiography. Histological analysis demonstrated a significant difference in bone formation between animals in group L (p = 0.049) at day 60 than in other groups. Higher rates of inflammatory infiltrates and fibrosis were observed in the LP and PC groups at days 30 and 60, whereas the groups not receiving PC showed a higher rate of bone maturity. The inflammatory processes were reduced in the animals in the L group, together with new bone formation and maturation. Groups L and C had higher scores of positive osteocalcin immunostaining in bone and extracellular matrix. CONCLUSIONS: LLLT reduces inflammation and contributes to increased bone formation. PC treatment was shown to maintain connective tissue and to induce fibrosis during bone repair. Combined LLLT and PC treatment did not improve bone repair.