Single intraoperative infrared laser optimized bone repair in rat femoral osteotomies with experimentally induced osteoporosis.

This study aimed to evaluate the effect of infrared laser (IRL) on bone repair in ovariectomized rats subjected to femoral osteotomies. Of 32 rats, half underwent bilateral ovariectomy (OVX) and the other half underwent sham ovariectomy (SHAM). A period of 3 months was defined to observe the presence of osteoporosis. The rats were subjected to osteotomies in the femurs and then fixed with a miniplate and 1.5-mm system screws. Thereafter, half of the rats from both SHAM and OVX groups were not irradiated, and the other half were irradiated by IRL using the following parameters: wavelength, 808 nm; power, 100 mW; 60 s for each point; 6 J/point; and a total of 5 points of bone gap. All animals were euthanized 60 days after surgery. The femur gap was scanned using micro-computed tomography (micro-CT). The samples were then examined under a confocal laser microscope to determine the amounts of calcein and alizarin red. The slides were stained with alizarin red and Stevenel's blue for histometric analysis. In the micro-CT analysis, the OVX groups had the lowest bone volume (P < 0.05). When the laser was applied to the OVX groups, bone turnover increased (P < 0.05). New bone formation (NBF) was comparable between SHAM and OVX/IR (P > 0.05) groups; however, it was less in the OVX groups (P < 0.05). In conclusion, the results encourage the use of IRL intraoperatively as it optimizes bone repair, mainly in animals with low bone mineral density.

A triple-blind randomized clinical trial of different associations between dexamethasone and non-steroids anti-inflammatories for preemptive action in third molar extractions.

The aim of this study is to evaluate the preemptive analgesic effects of dexamethasone (DEX) alone or combined with non-steroidal anti-inflammatory drugs (NSAIDs) in third molar surgeries. The subjects were divided into five groups (n = 20 teeth/group); subjects received only 8 mg of dexamethasone 1 h before the surgical procedure (DEX group), or in combination with etodolac (DEX + ETO), ketorolac (DEX + KET), ibuprofen (DEX + IBU), loxoprofen (DEX + LOX). Paracetamol 750 mg was provided as the number of rescue analgesics (NRA). Salivary PGE2 expression was measured preoperatively and at 48 h. Edema and Maximum mouth opening (MMO) were measured postoperatively at 48 h and 7 days. A visual analog scale (VAS) was performed postoperatively at 6, 12, 24, 48, 72 h, and 7 days. Salivary expression of PGE2 showed a decrease only for the DEX group. Edema and MMO and NRA consumption showed no significant differences among the groups (P > 0.05). The VAS showed a significantly lower pain perception at 6 h after the surgery for the DEX + ETO and DEX + KET groups (P < 0.05). The combination of DEX and NSAIDS should be considered for preemptive acute postsurgical pain management in third molar surgery. In some drug associations such as dexamethasone 8 mg + NSAIDS (ETO and KET) in the pre-operative time, only a few rescue analgesics are necessary.

Titanium Allergy Caused by Dental Implants: A Systematic Literature Review and Case Report.

(1) Background: Hypersensitivity reactions to metals may arise in predisposed patients chronically exposed to metallic materials, including dental implants made of titanium alloys. The purpose of this article was to systematically review titanium allergy manifestations in patients treated with dental implants and report a clinical case; (2) Methods: A systematic electronic search was performed for articles published in the English language until July 2021. The following eligibility criteria were adopted: (1) Population: individuals undergoing titanium and/or titanium alloy implant-supported rehabilitations; (2) Exposure: peri-implant soft tissue reactions attributable to implant insertion; (3) Outcome: evidence of titanium allergy, diagnostic methods, and forms of resolution; (3) Results: The included studies, in summary, presented evidence that titanium should not be considered an inert material, being able to trigger allergic reactions, and may be responsible for implant failure. A 55-year-old male patient received 3 implants in the posterior region of the left mandible and presented an epulis-like lesion developed from the peri-implant mucosa. The immunohistochemical analysis of the biopsy specimen confirmed the initial diagnosis of allergic reaction to titanium; (4) Conclusions: Although the evidence is weak, and titanium allergy has a low incidence, hypersensitivity reactions should not be underestimated. A rapid and conclusive diagnosis is mandatory to prevent further complications.

Is an anodizing coating associated to the photobiomodulation able to optimize bone healing in ovariectomized animal model?

This in vivo study investigated whether the bioactivity of anodizing coating, produced by plasma electrolytic oxidation (PEO), on mini-plate in femur fracture could be improved with the association of photobiomodulation (PBM) therapy. From the 20 ovariectomized Wistar female rats, 8 were used for model characterization, and the remaining 12 were divided into four groups according to the use of PBM therapy by diode laser (808 nm; power: 100 mW; energy: 6.0 J; energy density: 212 J/cm2; power density: 3.5 W/cm2) and the type of mini-plate surface (commercially pure titanium mini-plate -cpTi- and PEO-treated mini-plate) as follow: cpTi; PEO; cpTi/PBM; and PEO/PBM. After 60 days of surgery, fracture healing underwent microstructural, bone turnover, histometric, and histologic adjacent muscle analysis. Animals of groups with PEO and PBM showed greater fracture healing than cpTi control group under histometric and microstructural analysis (P < 0.05); however, bone turnover was just improved in PBM's groups (P < 0.05). there was no difference between cpTi and PEO without PBM (P > 0.05). Adjacent muscle analysis showed no metallic particles or muscle alterations in all groups. PEO and PBM are effective strategies for bone repair in fractures, however their association does not provide additional advantages.

Miniplates coated by plasma electrolytic oxidation improve bone healing of simulated femoral fractures on low bone mineral density rats.

The treatment of polytrauma patients represents a great challenge in the maxillofacial and orthopedic surgery fields. Therefore, this study tested the hypothesis that the use of a bioactive coating (by plasma electrolytic oxidation, PEO) on titanium microplates could improve the fracture healing of low bone mineral density (BMD) rats. Thirty female rats underwent bilateral ovariectomy surgery (OVX), and 35 rats underwent fake surgery (SHAM). Three months later, animals were subjected to femoral fracture simulation and were fixed with either non-coated (CONV) or coated (PEO) titanium miniplates. Eight weeks postoperatively, microplate/bone complexes were analyzed through computed microtomography, histometric, confocal microscopy, molecular, and biomechanical analysis. Bioactive elements (Ca and P) were incorporated on the PEO microplate and the surface was modified in a volcano-like structure. In the microCT analysis the OVX/PEO group had greater values for Tb.Th (bone trabecular thickness), Tb.Sp (separation of bone trabeculae) and Tb.N (number of trabeculae) parameters compared to the OVX/CONV group. According to histometric analysis, the OVX/PEO group showed significantly higher new bone formation than the OVX/CONV group (P < 0.05). For the fluorochrome area, the OVX groups (PEO and CONV) showed greater values for calcein precipitation (old bone) than alizarin red (new bone). Molecular results showed greater values for proteins related to the final phase of bone formation (P < 0.05) in the OVX/PEO group. The OVX/PEO group showed higher bone/miniplate system resilience compared to the others (P < 0.05). It was concluded that PEO coating optimizes bone healing on simulated femoral fractures in low bone mineral density rats. This sheds new light in the treatment of osteoporotic patients with bone fractures.

Author Correction: Plasma Electrolytic Oxidation as a Feasible Surface Treatment for Biomedical Applications: an in vivo study.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Plasma Electrolytic Oxidation as a Feasible Surface Treatment for Biomedical Applications: an in vivo study.

OBJECTIVES: In this in vivo animal study, we evaluated the effect of plasma electrolytic oxidation (PEO) coating on the topographic and biological parameters of implants installed in rats with induced osteoporosis and low-quality bones. MATERIALS AND METHODS: In total 44 Wistar rats (Rattus novergicus), 6 months old, were submitted to ovariectomy (OXV group) and dummy surgery (SHAM group). After 90 days, the ELISA test was performed and the ovariectomy effectiveness was confirmed. In each tibial metaphysis, an implant with PEO coating containing Ca2+ and P5+ molecules were installed, and the other tibia received an implant with SLA acid etching and blasting (AC) (control surface). After 42 days, 16 rats from each group were euthanized, their tibias were removed for histological and immunohistochemical analysis (OPG, RANKL, OC and TRAP), as well as reverse torque biomechanics. Data were submitted to One-way ANOVA or Kruskal-Wallis tests, followed by a Tukey post-test; P < 0.05. Histological analyses showed higher bone neoformation values among the members of the PEO group, SHAM and OVX groups. Immunohistochemical analysis demonstrated equilibrium in all groups when comparing surfaces for TRAP, OC and RANKL (P > 0.05), whereas OPG showed higher PEO labeling in the OVX group (P < 0.05). Biomechanical analysis showed higher reverse torque values (N.cm) for PEO, irrespective of whether they were OVX or SHAM groups (P < 0.05). CONCLUSION: The results indicated that the PEO texturing method favored bone formation and showed higher bone maturation levels during later periods in osteoporotic rats.

Avaliação dos princípios de fotobiomodulação e bioatividade na otimização do reparo ósseo na fixação de fraturas em ratas ovariectomizadas / Biomodulation and bioactivity principles evaluation in the optimization of bone repair in fixation of fractures in ovariectomized rats

Este trabalho teve como objetivo avaliar o efeito da biomodulação e bioatividade no reparo ósseo de ratas ovariectomizadas submetidas à simulação de fraturas femurais. Sessenta e quatro ratas Wistar (Rattus novergicus), fêmeas, com 6 meses de idade, em que metade dos animais foram submetidos à ovariectomia bilateral (OVX) e a outra metade à cirurgia fictícia de ovariectomia (SHAM), e um período de 3 meses foi acompanhado para a verificar se a osteoporose estava presente. As ratas foram submetidas à simulação de fratura em ambos os fêmures e a fratura foi fixada com miniplaca e parafusos do sistema 1,5 mm. A metade das amostrastiveram miniplacas com texturização de superfície tratadas por oxidação com plasma eletrolítico (PEO), que ficou em contato com o "gap" reparacional e, a outra metade com miniplacas convencionais, com superfície (CONV). Estes grupos experimentais não foram submetidos à biomodulação (CO). Para o mesmo desenho experimental dos grupos, no ato operatório, após a fixação das fraturas, os demais grupos experimentais foram submetidos à fotobiomodulação por meio da irradiação do laser de baixa intensidade (LASER), durante 5 minutos. Aos 14 e 42 dias de pós-operatório, foi administrada calceína e alizarina, respectivamente, pela via intramuscular, na dose de 20 mg/kg de peso. A eutanásia de todos os animais foi realizada aos 60 dias de pós-operatório. Os grupos experimentais (SHAM/LASER/CONV; SHAM/CO/CONV; SHAM/LASER/PEO; SHAM/CO/PEO; OVX/LASER/CONV; OVX/CO/CONV; OVX/LASER/PEO; OVX/CO/PEO), após a eutanásia, tiveram as regiões de interesse, inicialmente escaneadas em microtomografia computadorizada para avaliação dos parâmetros volumétricos do osso (BV/TV) e qualidade óssea PO(tot) (Tb.Th, Tb.Sp e Tb.N), em seguida as peças continuaram em processamento para inclusão em resina fotopolimerizável. As lâminas foram escaneadas em microscopia confocal a laser para análise da área em pixels2 de precipitação mineral óssea (APMO). Após este processo, as lâminas foram coradas em vermelho de alizarina e azul de Stevenel para histometria de área de osso neoformado (NBF) no "gap" reparacional e análise do padrão reparacional. Os resultados foram inferiores e estatisticamente significantes (p< 0,05) na análise de MicroCT na comparação do grupo OVX/CO/CONV com os demais grupos nos parâmetros (BV.TV, Tb.N e Tb.Th); APMO apresentou menor área para o fluorocromo vermelho de alizarina nos grupos OVX/CO/CONV e OVX/CO/PEO (p<0,05). No grupo OVX, o laser mostrou maior turnover ósseo (p< 0,05) para NBF e pior padrão histológico. Conclusão: A fotobiomodulação e bioatividade otimizaram o reparo ósseo de fraturas em fêmures de ratas ovariectomizadas(AU)

The aim of this study was to evaluate the effect of biomodulation and bioactivity on the bone repair of ovariectomized rats submitted to simulation of femoral fractures. 64 female adults Wistar rats (Rattus novergicus), which half of the animals was submitted to bilateral ovariectomy (OVX) and the other half to the dummy ovariectomy surgery (SHAM), and after 3-month the osteoporosis was induced. The rats were submitted to fracture simulation in both of the femurs and the fracture was fixed with miniplate and screws of the system 1.5 mm. Half of the samples had surface-textured miniplatestreated by with plasma electrolytic oxidation (PEO), which was in contact with the repair gap, and the other half with conventional miniplates with surface (CONV). These experimental groups were not submitted to biomodulation (CO). For the same experimental design of the groups, after fracture fixation, the other experimental groups were submitted to photobiomodulation through low level laser (laser), for 5 minutes. At 14 and 42 postoperative days, calcein and alizarin, respectively, were administered intramuscularly at a dose of 20 mg / kg body weight. The animals were euthanized at 60 postoperative days. The experimental groups (SHAM/LASER/CONV, SHAM/CO/CONV, SHAM/LASER/PEO, SHAM/CO/PEO, OVX/LASER/CONV, OVX/CO/CONV, OVX/LASER/PEO), after euthanasia, had the regions of interest, initially scanned in computerized microtomography to evaluate the bone volume parameters [BV / TV] and bone quality PO (tot) and (Tb.Th, Tb.Sp and Tb.N), then the samples were processed for inclusion in photopolymerizable resin.. The slides were scanned in confocal laser microscopy for analysis of the area in pixels2 of bone mineral precipitation (APMO). After this process, the slides were stained in alizarin red and Stevenel blue for neoformed bone area (NBF) in the reparative gap and analysis of the histology pattern. The results showed lower and statistically significant results (p <0.05) for MicroCT parameters (BV.TV, Tb.N and Tb.Th) in the comparison between OVX / CO / CONV and the other groups; APMO showed lower area for the alizarin red fluorochrome in the OVX / CO / CONV and OVX / CO / PEO groups (p <0.05). In the OVX, the laser showed greater bone turnover (P<0,05); The OVX / CO / CONV showed lower NBF (p <0.05) and worse histological pattern. Conclusion: The photobiomodulation and bioactivity optimized the bone repair of femur fractures in ovariectomized rats(AU)

Implantes dentários curtos na implantodontia moderna: revisão sistematizada / Short implants dental in modern implantology: systematized review / Implantes dentales curtos en la implantodontia moderna: revisión sistematizada

Introdução: Os implantes curtos têm ganhado espaço na implantodontia moderna devido se tratar de uma técnica que apresenta baixa morbidade, sem necessidade de cirurgias de enxertos prévias e menor custo para o paciente, quando comparada a outras técnicas. Objetivo: Dessa forma, foi realizada uma revisão da literatura atual sobre as vantagens e indicações desta técnica comparando-a as técnicas convencionais. Materiais e métodos: A pesquisa bibliográfica foi realizada usando MEDLINE via PubMed, utilizando termos e outros termos livres dos Cabeçalhos de Assunto Médicos (MeSH) para pesquisar. Abrangendo artigos publicados em inglês, dos ultimos 18 anos. Resultados: Foram selecionados 56 referências, das quais 26 foram consideradas inadequadas. Resultando no total de 30 artigos considerados adequados aos critérios de seleção. Os artigos selecionados apresentaram em alguns pontos divergência que ainda necessitam de respostas baseadas em evidencias. Conclusão: Conclui-se com esta revisão que os implantes curtos são uma boa alternativa quando não se tem altura óssea suficiente para instalação de implantes convencionais, e que apresenta vantagens e indicações restritas no universo da implantodontia com resultados similares quando comparados aos implantes de tamanhos convencionais. Porém, apresentam resultados a curto prazo o que sugere a realização de estudos com longo tempo de acompanhamento que busquem responder sobre a qualidade da técnica nos diversos desafios encontrados na implantodontia(AU)

Introduction: The short implants have an open space in modern implantology due to a technique that presents low morbidity, without previous grafting surgeries and lower cost for the patient, when compared to other techniques. Objective: Thus, a review of current literature on the advantages and indications of technique was carried out comparing conventional techniques. Materials and methods: Bibliographic research was conducted using MEDLINE via PubMed, using terms and other free Medical Subject Headings (MeSH) terms to search for. Covering articles published in English, from the last 18 years. Results: We selected 56 references, of which 26 were considered inadequate. Resulting in a total of 30 articles considered adequate to the selection criteria. The selected articles presented in some points divergence that still need evidence based answers. Conclusion: It was concluded with this review that short implants are a good alternative when there is not enough height for the installation of conventional implants, and that they have advantages and restricted indications no universe of the implantology with similar results when compared to the implants of conventional sizes. However, results of a short term and that suggests a course of studies with a time of accompaniment that seek answers on a quality of the technique in the diverse challenges found in the implantology(AU)

Introducción: Los implantes cortos han ganado espacio en la implantodoncia moderna debido a que se trata de una técnica que presenta baja morbilidad, sin necesidad de cirugías de injertos previos y menor costo para el paciente, en comparación con otras técnicas. Objetivo: De esta forma, se realizó una revisión de la literatura actual sobre las ventajas e indicaciones de esta técnica comparándola con las técnicas convencionales. Materiales y métodos: La investigación bibliográfica fue realizada usando MEDLINE vía PubMed, utilizando términos y otros términos libres de los Cabeceros de Asunto Médicos (MeSH) para investigar. Abriendo artículos publicados en inglés, de los últimos 18 años. Resultados: Se seleccionaron 56 referencias, de las cuales 26 fueron consideradas inadecuadas. Resultando en el total de 30 artículos considerados adecuados a los criterios de selección. Los artículos seleccionados presentaron en algunos puntos divergencia que aún necesitan respuestas basadas en evidencias. Conclusión: Se concluye con esta revisión que los implantes cortos son una buena alternativa cuando no se tiene suficiente altura ósea para instalación de implantes convencionales y que presenta ventajas e indicaciones restringidas en el universo de la implantodoncia con resultados similares en comparación con los implantes de tamaños convencionales. Sin embargo, presentan resultados a corto plazo lo que sugiere la realización de estudios con largo tiempo de acompañamiento que busquen responder sobre la calidad de la técnica en los diversos desafíos encontrados en la implantodoncia(AU)

Daily melatonin administration improves osseointegration in pinealectomized rats.

INTRODUCTION: The hypothesis of this study was that the peri-implant bone healing of the group of pinealectomized rats would differ from the control group. The samples were subjected to immunohistochemical, microtomographic (total porosity and connectivity density), and fluorochrome (mineralized surface) analyses. OBJECTIVES: The goal of this study was to investigate the cellular changes and bone remodeling dynamics along the bone/implant interface in pinealectomized rats. MATERIAL AND METHODS: The total of 18 adult male rats (Rattus norvegicus albinus, Wistar) was divided into three groups (n=6): control (CO), pinealectomized without melatonin (PNX) and pinealectomized with melatonin (PNXm). All animals were submitted to the first surgery (pinealectomy), except the CO group. Thirty days after the pinealectomy without melatonin, the second surgery was conducted, in which all animals received an implant in each tibia (36 titanium implants with surface treatment were installed - Implalife® São Paulo, SP, Brazil). By gavage, the rats of the PNX group received the vehicle solution, and the procedure. RESULTS: Immunohistochemical analysis for runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC) showed that the bone repair process in the PNXm group was similar to that of the CO group, whereas the PNX group showed a delay. The microtomographic parameters of total porosity [Po(tot)] and bone surface (BS) showed no statistically significant differences, whereas for the connective density (Conn.Dn) a statistical difference was found between the CO and PNXm groups. Fluorochrome analysis of the active mineralized surface showed statistically significant difference between the CO and PNX and between the CO and PNXm groups. CONCLUSION: The absence of the pineal gland impaired the bone repair process during osseointegration, however the daily melatonin replacement was able to restore this response.

A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis.

Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

Short-Blunt Injury in Child Resulting From Pet Bite.

The frequency of accidents due to dog bite in children is high, and in the most cases, the child already knows the aggressor dog. Patient, 3 years, female, melanoderm, victim of pet dog attack on the right side of the face region. After the physical examination, conscious sedation was performed with the supplementation of oxygen by pediatrics and the suture by oral and maxillofacial surgeon, under local anesthesia with adrenergic vasoconstrictor, with internal points in the muscles using vicryl 4-0 and in the skin with 5-0 nylon; the lesser number of stitches were performed in the lower region of the wound, allowing spontaneous drainage spaces. The immediate wounds closure of dog bites on the face is safe, even in cases after several hours of the injury.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria.

OBJECTIVE: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. MATERIAL AND METHODS: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in µCT were obtained to calculate bone mineral density (BMD). RESULTS: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The µCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). CONCLUSION: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Raloxifene but not alendronate can compensate the impaired osseointegration in osteoporotic rats.

OBJECTIVES: Alendronate and raloxifene, a bisphosphonate and a selective estrogen modulator, respectively, are established osteoporosis therapies. Current evidence suggests that simultaneous application of osteoporosis therapies modulates osseointegration. However, alendronate shows inconsistent findings and raloxifene has not been studied comprehensively. This study aimed to evaluate the bone dynamics and molecular and microstructural features at the peri-implant bone interface in osteoporotic rats. MATERIALS AND METHODS: Thirty female rats underwent ovariectomy and were fed a diet low in calcium and phosphate and treated with alendronate or raloxifene for 30 days or underwent fictional ovariectomy surgery (SHAM) prior to implant insertion in the tibia; osteoporosis therapies continued thereafter. After 42 days, peri-implant bone was evaluated by histometric and micro-CT analysis. Fluorochrome incorporation and gene expression was determined to evaluate bone turnover. RESULTS: We report here that alendronate had no impact on bone-to-implant contacts and the mineral apposition rate. The RANKL/OPG ratio and local bone volume, however, were increased compared to the untreated osteoporotic rats. Even though signaling to bone resorption activity through RANKL production was observed in the alendronate group, the blockade of bone resorption activity that occurs in decorrence to alendronate activity took place and resulted in an increase in bone volume. Raloxifene significantly increased osseointegration in osteoporotic rats, as indicated by bone-to-implant contacts, mineral apposition, and local bone volume. Raloxifene, however, had no considerable impact on the RANKL/OPG ratio compared to untreated osteoporotic rats. As expected, the SH group showed higher bone-to-implant contacts and mineral apposition rates than the untreated osteoporotic rats. CONCLUSIONS: These findings suggest that raloxifene but not alendronate can compensate for the impaired osseointegration in osteoporotic rats. CLINICAL RELEVANCE: Regarding the superiority of raloxifene observed in the improvement of bone dynamics response, this statement suggests that raloxifene could be a good option for osteoporosis patients in oral rehabilitation procedures.

Daily melatonin administration improves osseointegration in pinealectomized rats

Abstract The hypothesis of this study was that the peri-implant bone healing of the group of pinealectomized rats would differ from the control group. The samples were subjected to immunohistochemical, microtomographic (total porosity and connectivity density), and fluorochrome (mineralized surface) analyses. Objectives The goal of this study was to investigate the cellular changes and bone remodeling dynamics along the bone/implant interface in pinealectomized rats. Material and Methods The total of 18 adult male rats (Rattus norvegicus albinus, Wistar) was divided into three groups (n=6): control (CO), pinealectomized without melatonin (PNX) and pinealectomized with melatonin (PNXm). All animals were submitted to the first surgery (pinealectomy), except the CO group. Thirty days after the pinealectomy without melatonin, the second surgery was conducted, in which all animals received an implant in each tibia (36 titanium implants with surface treatment were installed - Implalife® São Paulo, SP, Brazil). By gavage, the rats of the PNX group received the vehicle solution, and the procedure. Results Immunohistochemical analysis for runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC) showed that the bone repair process in the PNXm group was similar to that of the CO group, whereas the PNX group showed a delay. The microtomographic parameters of total porosity [Po(tot)] and bone surface (BS) showed no statistically significant differences, whereas for the connective density (Conn.Dn) a statistical difference was found between the CO and PNXm groups. Fluorochrome analysis of the active mineralized surface showed statistically significant difference between the CO and PNX and between the CO and PNXm groups. Conclusion The absence of the pineal gland impaired the bone repair process during osseointegration, however the daily melatonin replacement was able to restore this response.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.