Microtomographic, histomorphometric, and molecular features show a normal alveolar bone healing process in iNOS-deficient mice along a compensatory upregulation of eNOS and nNOS isoforms

Abstract Inducible nitric oxide synthase (iNOS) is one of the enzymes responsible for the synthesis of nitric oxide (NO), which is an important signaling molecule with effects on blood vessels, leukocytes, and bone cells. However, the role of iNOS in alveolar bone healing remains unclear. This study investigated the role of iNOS in alveolar bone healing after tooth extraction in mice. Methodology C57Bl/6 wild type (WT) and iNOS genetically deficient (iNOS-KO) mice were subjected to upper incision tooth extraction, and alveolar bone healing was evaluated by micro-computed tomography (μCT) and histological/histomorphometric, birefringence, and molecular methods. Results The expression of iNOS had very low control conditions, whereas a significant increase is observed in healing sites of WT mice, where iNOS mRNA levels peak at 7d time point, followed by a relative decrease at 14d and 21d. Regarding bone healing, both WT and iNOS-KO groups showed the usual phases characterized by the presence of clots, granulation tissue development along the inflammatory cell infiltration, angiogenesis, proliferation of fibroblasts and extracellular matrix synthesis, bone neoformation, and remodeling. The overall micro-computed tomography and histomorphometric and birefringence analyses showed similar bone healing readouts when WT and iNOS-KO strains are compared. Likewise, Real-Time PCR array analysis shows an overall similar gene expression pattern (including bone formation, bone resorption, and inflammatory and immunological markers) in healing sites of WT and iNOS-KO mice. Moreover, molecular analysis shows that nNOS and eNOS were significantly upregulated in the iNOS-KO group, suggesting that other NOS isoforms could compensate the absence of iNOS. Conclusion The absence of iNOS does not result in a significant modulation of bone healing readouts in iNOS-KO mice. The upregulation of nNOS and eNOS may compensate iNOS absence, explaining the similar bone healing outcome in WT and iNOS-KO strains.

Prevalência de radiolucência justa-apical e sua relação com terceiros molares inferiores em radiografias panorâmicas / Prevalence of juxta-apical radiolucency and association/relations with the lower third molar in panoramic radiography

Objetivo: Avaliar a prevalência da radiolucência justa-apical (RJA) e sua relação com os terceiros molares inferiores, em 1054 radiografias panorâmicas. Métodos: A amostra foi constituída por radiografias panorâmicas digitais de indivíduos maiores de 18 anos, com pelo menos um terceiro molar inferior. As imagens foram analisadas para a presença de RJA em relação à corticalização, localização, relação com o canal mandibular, angulação e profundidade de impactação do terceiro molar. Os dados foram analisados através de estatística descritiva e pelo teste Qui-quadrado, sendo que valores de p < 0,05 foram considerados como significativos. Resultados:Foi encontrada uma prevalência de 2,75% de RJA, sendo predominante no sexo feminino (p = 0,01). A RJA foi visualizada em maior número corticalizada (58,63%), lateroapical (48,27%), em dentes parcialmente intraósseo (68,97%) e mesioangulados (55,17%). Em relação ao canal mandibular, houve maior prevalência na posição sobreposta ao canal mandibular (65,52%). Conclusão: A prevalência de RJA foi de 2,75% do total de 1054 radiografias panorâmicas avaliadas. Em relação ao canal mandibular, apresentou maior prevalência sobreposto. Além disso, a maior parte das RJA se apresentaram corticalizadas, em posição lateroapical, associada a dentes em posição mesioangular. Descritores: Radiografia panorâmica. Dente serotino. Nervo mandibular.Prevalência de radiolucência justa-apical e sua relação com terceiros molares inferiores em radiografias panorâmicas

Aim: To evaluate the prevalence of juxta-apical radiolucency (JAR) and its relationship with the lower third molars and adjacent structures, in 1,054 panoramic radiographs. Methods: The sample consisted of digital panoramic radiographs of individuals over 18 years of age, with at least one lower third molar. The images were analyzed for the presence of JAR in relation to corticalization, location, impaction depth, relationship with the mandibular canal, angulation, and impaction of the third molar. Data were analyzed using descriptive statistics and the chi-square test, and values of p < 0.05 were considered significant.Results: A prevalence of 2.75% of JAR was found, with a statistical difference between JAR and gender (p = 0.01), which proved to be predominant in females. The JAR was seen in greater numbers as corticalized (58.63%), lateroapical (48.27%), and mesioangulated (55.17%), as well as in erupted teeth (31.03%). In relation to the mandibular canal, it presented a higher prevalence when superimposed upon the mandibular canal (65.52%). Conclusions:The prevalence of RJA was 2.75% of the 1,054 evaluated panoramic radiographs. In relation to the mandibular canal, it presented a higher prevalence of superimposition. In addition, most of the RJA were corticalized, in a lateroapical position, associated with teeth in a mesioangular position. Uniterms: Panoramic radiography. Third molar. Mandibular nerve.

Dental management in the Intensive Care Unit in the treatment of toxic epidermal necrolysis associated with phenytoin: case report / Manejo odontológico na Unidade de Terapia Intensiva no tratamento da necrólise epidérmica tóxica associada a fenitoína: relato de caso

ABSTRACT Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are adverse reactions, usually medicine-related, in which extensive and painful mucocutaneous lesions are formed. Oral lesions are characterized by the presence of erosions and ulcers. The treatment usually requires intensive care in a hospital setting, where the Dentist is essential in the multidisciplinary team, as he will act in the treatment of oral lesions. In this article, a 26-year-old female patient was reported, who presented TEN-compatible mucocutaneous lesions associated with the drug Phenytoin and required admission to a Teaching Hospital. The treatment consisted of the immediate suspension of the Phenytoin use and systemic therapy with corticosteroids and immunosuppressants. Oral lesions were monitored by the hospital dentistry team. The procedures adopted were: oral hygiene with 0.12% non-alcoholic Chlorhexidine Digluconate solution, hydration of the oral tissue with an essential fatty acid, application of frozen chamomile tea, and prescription of topical Triamcinolone Acetonide. Also, low-level laser therapy sessions (red and infrared) were performed. Oral lesions evolved with significant improvement. In this case, the importance of the Dentist in the multi-professional team is demonstrated. Although there is no protocol, the procedures used in the present case can be an alternative to therapies used in SSJ and TEN oral lesions.

RESUMO A Síndrome de Stevens Johnson (SSJ) e a Necrólise Epidérmica Tóxica (NET) são reações adversas, geralmente medicamentosas. Na pele, formam-se máculas que se tornam pápulas, vesículas e bolhas, além de eritema extenso e desprendimento da epiderme. As lesões bucais caracterizam-se pela presença de erosões e úlceras dolorosas. O tratamento geralmente é realizado em âmbito hospitalar, com necessidade de cuidados intensivos, onde o Cirurgião-dentista é fundamental na equipe multiprofissional, pois atuará na terapêutica das lesões bucais. Neste artigo foi relatado o caso de uma paciente do sexo feminino, de 26 anos, a qual apresentou lesões mucocutâneas compatíveis com NET associadas ao medicamento Fenitoína e necessitou de internamento em um Hospital Universitário. O tratamento realizado foi a suspensão imediata do fármaco desencadeador, além de terapia sistêmica com corticóide e imunossupressor. As lesões bucais foram acompanhadas pela equipe de odontologia hospitalar. As condutas adotadas foram: higiene bucal com solução de Digluconato de Clorexidina 0,12% não alcoólica, hidratação da mucosa bucal com Ácido Graxo Essencial, aplicação de raspas de chá de gelo de camomila e prescrição de Triancinolona Acetonida tópica. Além disso, foram realizadas sessões de laserterapia de baixa intensidade (vermelho e infravermelho). As lesões bucais evoluíram com melhora significativa. A paciente permaneceu internada durante 22 dias, sendo 12 em Unidade de Terapia Intensiva. Este caso demonstra a importância do Cirurgião-dentista na equipe multiprofissional. Apesar de não haver um protocolo para as lesões bucais, as condutas utilizadas no presente caso podem ser uma alternativa de terapêuticas utilizadas em lesões de SSJ e NET.

Absence of medication-related jaw osteonecrosis after treatment with strontium ranelate in ovariectomized rats

Abstract This study aimed to evaluate the potential of strontium ranelate (SR) in medication-related jaw osteonecrosis (MRONJ) after tooth extraction in ovariectomized rats. Thirty ovariectomized rats were divided into three groups (n = 10): bisphophonate (BP) group (zoledronic acid; 0.4 mg/kg/week), SR group (625 mg/kg/day), and control group (saline solution). The lower first molars were extracted after 60 days of drug therapy. Drug administration was continued for another 30 days after tooth extraction. The mandibles were subjected to clinical, histological, radiographic, and microtomographic evaluations. Only the BP group showed clinical changes, characterized by the presence of 70% (n = 7) and 20% (n = 2) of ulcers and extraoral fistulas. Radiographic evaluation demonstrated bone sequestration only in the BP group (n = 7, 70%). Microtomographic analysis revealed increased bone porosity after ovariectomy, particularly in the the control group (p < 0.05). The BP group showed a higher bone surface density, bone volume, and trabecular number than SR and control groups, but with less trabecular separation (p < 0.05). All the animals in the BP group demonstrated histological osteonecrosis. There was no evidence of osteonecrosis in the control and SR groups, which was characterized by the absence of empty osteocyte gaps and associated with the gradual healing of the extraction area. Also, an increased number of blood vessels and a reduced number of osteoclasts were observed in the SR group (p < 0.05). Therefore, SR treatment increased angiogenesis and osteoclastogenesis in the healing socket and was not associated with MRONJ development after tooth extraction in ovariectomized rats.

Prevalência das posições e grau de dificuldade cirúrgica de terceiros molares inferiores: um estudo radiográfico retrospectivo / Prevalence of positions and degree of surgical difficulty in lower third molars: a retrospective radiographic study

Objetivo: Os objetivos deste estudo foram avaliar a prevalência do posicionamento dos terceiros molares inferiores seguindo a classificação de Winter e Pell & Gregory, e determinar os níveis de dificuldade para a exodontia através do índice de Pederson. Materiais e Métodos: Estudo radiográfico, transversal e retrospectivo avaliou 100 radiografias panorâmicas provenientes dos prontuários odontológicos atendidos nos ambulatórios de Cirurgia bucal, de pacientes entre 15 e 61 anos de idade, no período de 2015 a 2017. As radiografias panorâmicas foram avaliadas por meio do software ImageJquanto aos posicionamentos dos terceiros molares inferiores pela classificação de Winter e Pell & Gregory, enquanto o nível de dificuldade foi avaliado pelo índice de Pederson. Os resultados obtidos foram submetidos à análise estatística descritiva. Resultados: A maior prevalência de terceiros molares inclusos foi observada em mulheres, com idade média de 26 anos. Quanto a posição dos dentes inclusos, a posições vertical (44,0%), nível A (74,7%) e classe III (69,9%) foram as mais prevalentes. Na escala de Pederson, a dificuldade cirúrgica "muito difícil" foi a mais encontrada. Discussão: nossos resultados sugerem estabelecer um melhor planejamento cirúrgico e prognóstico aos pacientes, minimizando a possibilidade de complicações durante e após as extrações de terceiros molares inferiores. Conclusão: Ambas classificações auxiliam o cirurgião-dentista a estabelecer um melhor planejamento e prognóstico aos pacientes. A aplicabilidade das radiografias panorâmicas, associados a avaliação clínica, justificam menores possibilidades de complicações pós-cirúrgicas em terceiro molar inferior.

Aim: The objectives of this study were to evaluate the prevalence of the mandibular third molars position in according to the Winter and Pell & Gregory classification, and to determine the levels of difficulty for exodontia through the Pederson index. Materials and Methods: Radiographic, cross-sectional and retrospective study evaluated 100 panoramic radiographs of patients between 15 and 61 years old, from dental records seen at the Oral Surgery department in the period from 2015 to 2017. The panoramic radiographs were evaluated using ImageJ software regarding the positioning of the lower third molars by the Winter and Pell & Gregory classification, while the level of difficulty was evaluated by the Pederson index. The results obtained were submitted to descriptive statistical analysis.Results: The highest prevalence of included third molars was observed in women, with an age average of 26 years. Regarding the position of the included teeth, the vertical position (44.0%), level A (74.7%), and class III (69.9%) were the most prevalent. In the Pederson scale, the "very difficult" surgical difficulty was the most found. Discussion: results suggest establishing better surgical planning and prognosis for patients, minimizing the possibility of complications during and after extractions of mandibular third molars.Conclusion: Both classifications help the dental surgeon to establish better planning and prognosis for patients. The applicability of panoramic radiographs, associated with clinical evaluation, justifies a fewer possibility of complications in the lower third molar post-extraction

Histological comparison between biphasic calcium phosphate and deproteinized bovine bone on critical-size bone defects

Abstract The limited options for bone repair have led to an extensive research of the field and the development of alloplastic and xenogeneic grafts. The purpose of this study was to evaluate bone repair with two bone substitutes: deproteinized bovine bone (DBB) and biphasic calcium phosphate ceramic (BCP) in critical-size defect. A total of 8-mm defects were made in the parietal bones of rabbits (n=12). The animals were divided into three experimental groups: sham (defect filled with a blood clot), DBB (defect filled with DBB), and BCP (defect filled with BCP). After the experimental periods of 15 and 45 days, the animals were euthanized and submitted to histomorphometric analysis. The total defect area, mineralized tissue area, biomaterial area, and soft tissue area were evaluated. A greater amount of immature bone tissue and biomaterial particles were observed in the BCP group compared to DBB and sham at 45 days (p<0.05). There was no difference in the qualitative pattern of bone deposition between DBB and BCP. However, the sham group did not show osteoid islands along with the defect, presenting a greater amount of collagen fibers as well in relation to the DBB and BCP groups. There was a greater number of inflammatory cells in the DBB at 45 days compared to BCP and sham groups. In conclusion, BCP and DBB are options for optimizing the use of bone grafts for maxillofacial rehabilitation. Bone defects treated with BCP showed greater deposition of bone tissue at 45 days.

Resumo As opções limitadas para reparo ósseo levaram ao desenvolvimento de abrangente pesquisa na área de enxertos aloplásticos e xenogênicos. O objetivo deste estudo foi avaliar o reparo ósseo com dois substitutos ósseos: osso bovino desproteinizado (DBB) e cerâmica fosfática de cálcio bifásica (BCP) em defeito de tamanho crítico. Material e métodos: defeitos críticos de 8 mm foram feitos nos ossos parietais de coelhos (n=12). Os animais foram divididos em três grupos experimentais: sham (defeito preenchido com coágulo sanguíneo), DBB (defeito preenchido com DBB) e BCP (defeito preenchido com BCP). Após os períodos experimentais de 15 e 45 dias, os animais foram sacrificados e submetidos à análise histomorfométrica. Foram avaliadas a área total de defeitos, área de tecidos mineralizados, área de biomateriais e área de tecidos moles. Resultados: maior quantidade de tecido ósseo imaturo e de partículas de biomaterial foram observados no grupo BCP em comparação aos grupos DBB e sham aos 45 dias (p<0,05). Não houve diferença no padrão qualitativo de deposição óssea entre DBB e BCP. Ainda, o grupo sham não apresentou ilhas osteóides ao longo do defeito, apresentando maior quantidade de fibras colágenas em relação aos grupos DBB e BCP. Houve maior quantidade de células inflamatórias no DBB aos 45 dias em comparação aos grupos BCP e sham. Conclusões: BCP e DBB são opções para otimizar o uso de enxertos ósseos na reabilitação de pacientes. Defeitos ósseos tratados com BCP mostraram maior deposição de tecido ósseo aos 45 dias.

Experimental acute sepsis reduced number of osteocalcin immunolabeled cells in periodontal ligament

Abstract The aim of this study was to evaluate the effect of acute sepsis in the periodontal ligament, alveolar and furcation bone in absence of periodontitis induction through histological and immunohistochemical analyses. A septic rat model was established by cecal ligation and puncture (CLP). Twelve rats were randomly divided into CLP (n=6) and Sham (n=6) groups. The animals were euthanized at 24 h and hemimandibles were submitted to histomorfometric (bone matrix, collagenous fibers, fibroblasts, osteocytes, inflammatory cells, and blood vessels) and immunohistochemical (BMP-2/4, RANKL and osteocalcin) evaluation in alveolar bone, furcation bone and periodontal ligament. Our results demonstrated that histomorphometric parameters were similar in alveolar bone, furcation bone and periodontal ligament of Sham and CLP rats. Regarding to immunohistochemical analyses, the number of BMP-2/4 and RANKL immunolabeled cells was also similar in both groups. Furthermore, it was detected a reduction in the osteocalcin immunolabeled cells in periodontal ligaments of CLP compared to Sham rats (p=0.0014). In conclusion, the acute sepsis induction resulted in reduced number of osteocalcin labelled cells in periodontal ligament region. Moreover, no significant histological differences were observed in the periodontium of rats under acute sepsis. Considering the role of osteocalcin in bone remodeling, the study contributes to revealing the importance of careful periodontal evaluation in the presence of sepsis.

Resumo O objetivo deste estudo foi avaliar o efeito da sepse aguda no ligamento periodontal, osso alveolar e osso da furca por meio de análise histológica e imunohistoquímica. O modelo de sepse em ratos foi estabelecido pelo procedimento de ligação e perfuração do ceco (CLP). Doze ratos foram divididos de forma randomizada em ratos sépticos (n=6) e controle - grupo Sham (n=6). Os animais foram eutanasiados após 24 horas e suas hemimandíbulas foram submetidas aos procedimentos histotécnicos para análise histomorfométricos (matriz óssea, fibras colágenas, fibroblastos, osteócitos, células inflamatórias e vasos sanguíneos) e imunohistoquímicos (BMP-2/4, RANKL e osteocalcina) no osso alveolar, osso de furca e ligamento periodontal. Nossos resultados demonstraram que os parâmetros histomorfométricos foram similares no osso alveolar, osso de furca e ligamento periodontal dos animais do grupo sepse e do grupo Sham. Em relação à análise por imunohistoquímica, o número de células imunomarcadas para BMP-2/4 e RANKL também foi similar em ambos os grupos. Entretanto, houve redução (p=0.0014) no número de células imunomarcadas para osteocalcina no ligamento periodontal de ratos sépticos em relação ao grupo Sham. Como conclusão, o estabelecimento de sepse aguda resultou em um número reduzido de células imunomarcadas para osteocalcina na região do ligamento periodontal (p=0,0014). Além disso, não foram observadas diferenças histológicas significativas no periodonto de ratos na presença de sepse aguda. Considerando o papel da osteocalcina na remodelação óssea, este estudo contribui para revelar a importância da avaliação periodontal cuidadosa na presença de sepse.

Evaluation of the bone anatomy of the anterior region of the mandible using cone beam computed tomography / Avaliação da anatomia da região anterior da mandíbula por meio de tomografia de feixe cônico

Background: Hemorrhages, mouth floor edema and tongue elevation are complications related to surgical procedures in the anterior region of the mandible. Objective: The objectives of this study were to evaluate the presence and location of the lingual foramen in the anterior region of the mandible and to evaluate mandibular morphology using cone beam computerized tomography (CBCT). Material and method: The mandible's morphology and the location, diameter and height of the lingual foramina were analyzed using the midline and the mental foramen as references, in 278 CBCT. Result: 88% of the sample had a midline lingual foramen, totaling 408 foramina, with a mean diameter of 0.93 mm. Foramina in the lingual region between the midline and mental foramina were detected in 75% of the sample, with a mean diameter of 0.807 mm. There was no positive correlation between the presence of lingual foramina in the lateral or in the midline regions (r = -0.149; p = 0.013). In the midline region, the type I mandibular shape was predominant (96%), and type III was predominant in the lateral regions. Conclusion: Considering the prevalence of these structures and their clinical relevance in potential surgical complications, it is important to carefully analyze the anterior region of the mandible during surgical planning.

Introdução: Hemorragias, edema no assoalho bucal e elevação da língua são complicações relacionadas a procedimentos cirúrgicos na região anterior da mandíbula. Objetivo: Os objetivos deste estudo foram avaliar a presença e localização do forame lingual na região anterior da mandíbula e avaliar a morfologia mandibular utilizando tomografia computadorizada com feixe de cone (CBCT). Material e método: A morfologia da mandíbula e a localização, diâmetro e altura do forame lingual foram analisados utilizando a medula e o forame mental como referências em 278 CBCT. Resultado: 88% da amostra tinha um forame lingual da linha média, totalizando 408 forames, com um diâmetro médio de 0,93 mm. Na região lingual entre a linha média e forames mentais foram detectados em 75% da amostra, com um diâmetro médio de 0,807 mm. Não houve correlação positiva entre a presença de forames lingual nas regiões lateral ou na região média (r = -0,149; p = 0,013). Na região da linha média, a forma mandibular do tipo I era predominante (96%) e o tipo III predominava nas regiões laterais. Conclusão: Considerando a prevalência dessas estruturas e sua relevância clínica em possíveis complicações cirúrgicas, é importante analisar cuidadosamente a região anterior da mandíbula durante o planejamento cirúrgico.

Histological analysis of the use of biphasic ceramics based on hydroxyapatite and B-tricalcium phosphate in maxillary sinus floor elevation surgery: pilot study / Análise histológica do uso da cerâmica bifásica a base de hidroxiapatita e B-tricálcio fosfato em cirurgia de elevação de assoalho de seio maxilar: estudo piloto

Objective: To evaluate the bone repair associated with the use of biphasic ceramics based on hydroxyapatite and β-tricalcium phosphate (HA/TCP) in the procedures of maxillary sinus membrane elevation in human beings. Material and method: Ten patients with a residual bone ridge in the posterior maxillary region between 3 mm and 5 mm in height were selected and indicated for procedures of bone grafting associated with maxillary sinus lift procedure. The maxillary sinuses were filled with HA/TCP, and after 8 months, the implants were implanted and a bone biopsy was collected with the aid of a trephine drill, which was then submitted to histological analysis for the evaluation of the composition of the grafted area. Result: The histological description analysis of the biopsies revealed the presence of vital and immature bone tissue, juxtaposed to the biomaterial. Histomorphometric analysis showed that the biopsy composition was in average 28.8%, 27.4%, and 43.6% of bone tissue, biomaterial, and soft tissue, respectively. Conclusion: The areas grafted with HA/TCP presented the adequate amount of bone formation that allowed the implantation of the implants. The success of the grafting procedure with this biomaterial was associated with its osteoconduction potential that allowed the formation of bone tissue in close contact with HA/TCP.

Objetivo: Avaliar o reparo ósseo associado ao uso da cerâmica bifásica a base de hidroxiapatita e β-tricálcio fosfato (HA/TCP) nos procedimentos de elevação da membrana do seio maxilar em humanos. Material e método: Foram selecionados 10 pacientes com rebordo ósseo residual entre 3 mm e 5 mm de altura na região posterior da maxila e que tinham indicação para procedimentos de enxertia óssea associado ao levantamento de seio maxilar. Os seios maxilares foram preenchidos com HA/TCP, e após 8 meses, foi executado a instalação dos implantes e nesse momento foi realizada a coleta de um fragmento ósseo com auxílio de uma broca trefina, o qual foi submetido à análise histológica da área enxertada. Resultado: A análise histológica das biópsias revelou a presença de tecido ósseo vital e imaturo, justaposto ao biomaterial. A análise histomorfométrica revelou percentuais de 28,8%, 27,4% e 43,6% para tecido ósseo, biomaterial e tecido mole, respectivamente. Conclusão: As áreas enxertadas com a HA/TCP apresentaram quantidade adequada de formação óssea que permitiu a instalação dos implantes. O sucesso do procedimento de enxertia com esse biomaterial esteve associado ao seu potencial de osteocondução que permitiu a formação de tecido ósseo em íntimo contato com a HA/TCP.

Use of miniplates as a method for orthodontic anchorage: a case report

ABSTRACT Introduction: Temporary anchorage devices (TADs) have been developed to be used as direct adjuncts in orthodontic treatment and have facilitated treatment of more complex orthodontic cases, including patients with dental impaction. Objectives: This clinical case reports the applicability of TADs in the orthodontic treatment of a patient with impacted mandibular second molars. Surgical and orthodontic procedures related to the use of miniplates were also discussed in this study. Conclusions: The use of temporary anchorage devices, such as miniplates, can be suggested as an alternative to treat patients with impacted mandibular second molars.

RESUMO Introdução: os dispositivos de ancoragem temporária vêm sendo desenvolvidos para uso como coadjuvantes no tratamento ortodôntico. Esses dispositivos facilitam o tratamento ortodôntico de casos mais complexos, incluindo pacientes com dentes impactados. Objetivos: o presente relato de caso reporta a aplicabilidade dos dispositivos de ancoragem temporária no tratamento ortodôntico de um paciente com segundos molares inferiores impactados. Os procedimentos cirúrgicos e ortodônticos relacionados ao uso das miniplacas também são discutidos nesse estudo. Conclusões: o uso de dispositivos de ancoragem temporária, tais como as miniplacas, pode ser sugerido como uma alternativa no tratamento de pacientes com segundos molares inferiores impactados.

Tomographic evaluation of atrophic maxilla rehabilitated with autogenous and xenogeneic block grafts

Aim: The aim of this study was to evaluate the dimensional stability of autogenous and xenogenous bone blocks after grafting procedures using cone beam computed tomography Material and Methods: Autogenous (n=6) and xenogeneic (n=7) bone graft blocks were evaluated after 8 (T1) and 16 (T2) months. A dimensional analysis was carried using linear measurements of the height and thickness of the blocks in the tomographic exam. Results: For the autogenous bone blocks, there was a reduction in height of 1.42mm (10.06%) and a reduction in mean thickness of 1.24mm (29.60%). For the xenogeneic bone blocks, the mean height reduction was 1.38mm (10.02%) and the mean thickness reduction was 0.97mm (18.81%) with remodeling (26.62%). However, there were no significant differences between the xenogeneic and autogenous bone blocks (p=0.366). Conclusions: The results showed no differences in the dimensional stability of autogenous or xenogenous bone graft blocks. However, clinical and experimental studies with longer follow up periods are needed to elucidate the mechanisms involved in the remodeling process of bone grafts.

Influence of Implant Surfaces on Osseointegration: A Histomorphometric and Implant Stability Study in Rabbits

Abstract: The aim of this study was to evaluate the stability and osseointegration of implant with different wettability using resonance frequency analysis (RFA) and histomorphometric analysis (bone implant contact, BIC; and bone area fraction occupied, BAFO) after 2 and 4 weeks in rabbit tibiae. Thirty-two Morse taper implants (length 7 mm, diameter 3.5 mm) were divided according to surface characteristics (n=8): Neo, sandblasted and dual acid-etched; and Aq, sandblasted followed by dual acid-etched and maintained in an isotonic solution of 0.9% sodium chloride. Sixteen New Zealand rabbits were used. Two implants of each group were installed in the right and left tibiae according to the experimental periods. The RFA (Ostell(r)) was obtained immediately and after the sacrifice (2 and 4 weeks). The bone/implant blocks were processed for histomorphometric analysis. Data were analyzed using two-way ANOVA followed by Tukey's test and Pearson's correlation for ISQ, BIC and BAFO parameters (p=0.05). No significant effect of implant, period of evaluation or interaction between implant and period of evaluation was found for BIC and BAFO values (p>0.05). Only period of evaluation had significant effect for RFA values at 4 weeks (p=0.001), and at 2 weeks (p<0.001). RFA values were significantly higher at the final period of evaluation compared with those obtained at early periods. There was a significant correlation between BIC values and BAFO values (p=0.009). Both implant surfaces, Aq and Neo, were able to produce similar implant bone integration when normal cortical bone instrumentation was performed.

Resumo: O objetivo deste estudo foi avaliar a estabilidade e osseointegração de implantes com superfícies com diferentes molhabilidades empregando análise de frequência de ressonância (RFA) e histomorfometria (contato implante ósseo, BIC, e fração de área óssea ocupada, BAFO), nos períodos de 2 e 4 semanas em tíbias de coelhos. Trinta e dois implantes cone Morse (comprimento 7mm, diâmetro 3,5 mm), foram divididos de acordo com tratamento de superfície (n = 8): Neo, superfície jateada e condicionada com ácido; e Aq, superfície jateada e condicionada com ácido e mantida em solução isotônica de cloreto de sódio a 0,9%. Dezesseis coelhos tipo Nova Zelândia foram utilizados neste estudo. Dois implantes de cada grupo foram instalados nas tíbias direita e esquerda de acordo com os períodos experimentais. Os valores de RFA (Ostell(r)) foram obtidos imediatamente e após o sacrifício (2 e 4 semanas). Os blocos ósseos/implante foram processados para análise histomorfométrica. Os dados foram analisados usando ANOVA fatorial seguido pelo teste de Tukey e também por meio de correlação de Pearson para os fatores RFA, BIC e BAFO (P=0,05). Nenhum efeito significativo dos fatores tipo de implante, período de avaliação e da interação entre o tipo de implante e período de avaliação foram observados para os valores de BIC e BAFO. Apenas o período de avaliação resultou em efeito significativo para valores RFA após 2 semanas (p=0,001), e 4 semanas (p<0,001). Os valores de RFA valores foram significativamente mais elevados no final do período de avaliação em comparação com os obtidos em inicialmente. Houve correlação significativa entre os valores BIC e BAFO (p=0,009). Ambas as superfícies de implantes, Aq e Neo, são capazes de produzir adequada integração osso/implante em condição normal de instrumentação do osso cortical.

La modulación de la expresión de IL-10 por el polimorfismo IL-10-592C/A (rs1800872) es independiente de la presencia y carga bacteriana de los periodontopatógenos clásicos / Modulation of IL-10 mRNA levels in periodontal lesions by IL-10-592C/A polymorphism (rs1800872) is independent of the frequency and load of classic periodontopathic bacteria

Objetivo: Reportamos la asociación entre el polimorfismo de nucleótido simple de IL-10-592C/A (rs1800872) y la detección/abundancia relativa de los periodontopatógenos Porfiromonas gingivalis, Tenerella forsythia, Treponema denticola y Aggregatibacter actinomycetemcomitans. Además investigamos la influencia de los determinantes genéticos y microbiológicos en los niveles de expresión de IL-10 en lesiones periodontales. Metodología Fueron reclutados 117 pacientes con periodontitis crónica y 58 controles. Luego del examen clínico fueron obtenidas muestras microbiológicas y la presencia/carga bacteriana de especies de periodontopatógenos fue cuantificada por RT-PCR. El genotipo para IL-10-592C/A fue determinado mediante restriction fragment length polymorphism. Resultados La distribución alélica del SNP rs1800872 en la población investigada cumplió con el equilibrio de Hardy-Weinberg (p = 0,64). Como ya ha sido reportado, los sujetos polimórficos demostraron menor expresión de IL-10 y riesgo aumentado de sufrir periodontitis crónica. El polimorfismo IL-10-592C/A no demostró relación con la detección o carga bacteriana de ninguna de las bacterias investigadas, además los niveles de expresión de IL-10 no fueron influenciados por el perfil microbiológico, sino que se correlacionaron directamente con el genotipo para el polimorfismo IL-10-592C/A.

Objective: A study was conducted to investigate the possible influence of the single nucleotide polymorphism (SNP) IL-10-592 C/A on the occurrence and load of the periodontal pathogens: P. gingivalis, T. forsythia, T. denticolaand A. Actinomycetemcomitans; as well to investigate the influence of microbial and genetic factors on the modulation of local IL-10 mRNA levels. Methodology The study included 117 cases and 58 controls. After clinical examination microbiological samples were obtained and the detection/quantification of the target bacterial species was performed by RT-PCR. SNP rs1800872 was assayed by restriction fragment length polymorphism (RFLP). Results Allele distribution of rs1800872 was in Hardy-Weinberg equilibrium (P = 64). As previously reported, polymorphic subjects demonstrated decreased IL-10 expression and increased risk of suffering chronic periodontitis. IL-10-592C/A rs1800872 SNP was not associated with the detection or the bacterial load of the investigated pathogens. Moreover, the presence/load of bacteria at periodontal sites did not influence IL-10 expression, which was determined by the genetic background of the study subjects. IL-10-592C/A SNP was not associated with detection/bacterial load of pathogenic bacteria. IL-10 expression levels were determined by the genetic background and were independent of the bacterial microenvironment.

Tratamento químico, mecânico e cirúrgico-regenerativo da peri-implantite: relato de caso clínico com nove meses de acompanhamento em um sítio mandibular posterior extenso / Chemical, mechanical, and surgical-regenerative treatment of peri-implantitis: a case report with nine months of follow-up in a large posterior mandibular site

A peri-implantite é caracterizada como uma lesão inflamatória localizada nos tecidos peri-implantares, sendo considerada uma das causas de perda tardia de implantes. O tratamento cirúrgico da peri-implantite abrange uma grande variedade de técnicas, diversos biomateriais para preenchimento dos defeitos ósseos e numerosos métodos dedescontaminação de superfícies. O debridamento aberto para descontaminação da superfície foi a abordagem mais utilizada e se mostrou mais efetivo para a resolução da peri-implantite, quando comparado ao debridamento fechado. Contudo, os resultados encontrados na literatura são controversos. Assim, outros estudos devem ser conduzidos, visando elucidar quais são as estratégias mais efetivas para o tratamento desta patologia. O objetivo deste estudo foi realizar uma revisão de literatura sobre o tratamento da peri-implantite, bem como apresentar um relato de caso clínico, no qual foi utilizada a regeneração óssea guiada para reconstrução das condições anatômicas perdidas.

Peri-implant diseases are characterized by local inflammatory lesions affecting the hard and soft tissues around an osteointegrated implant. It can be considered one of the major causes of late implant loss. Proposed treatments include surgical management, biomaterials, and numerous decontamination methods. The open debridement for decontamination of the surface was the technique most used and it was more effective for the resolution of peri-implantitis when compared to close debridement. However, some results are controversial. Further studies must be performed in order to describe effective and viable strategies to treat peri-implantitis. Therefore, the aim of this study was to review the pertinent literature and and to present a case report where GBR procedures were used to reconstruct the lack of anatomi­cal conditions.

Bone apposition and surface treatment in dental implants: histomorphometric pilot evaluation in rabbits

Introduction: The surface of dental implants is an important factor for osseointegration process and different methods of surface treatment have been described. Objective: To investigate the bone apposition in implant surface treated with sandblasting and acid-etching. Material and methods: Ten rabbits were selected and received one implant treated with method I in the left tibia and one implant treated with method II in the right tibia. Then, twenty implants were divided in two groups, according to methods of sandblasting and acid-etching (method I and method II). After 7, 14, 30, 45 and 60 days, tibias were retrieved and submitted to histotechnical procedures. The percentages of bone-implant contact (BIC) and bone area between threads (BABT) were determined throughout histomorphometric analysis and bone apposition was detected in implants of both groups. Results: In BABT measurements, an increase was observed after 45 and 60 days in the method II, compared to method I and no differences were found after 7, 14 and 30 days. In BIC measurements, an increase was detected with method II at 45 days when compared to method I. No differences between groups in BIC values were observed after 7, 14, 30 and 60 days. Conclusion: Our data demonstrated that implants treated with the method II presented increase in the contact between bone and implant after 45 days compared to method I. Moreover, with concern to bone area between threads, it was observed an increased in the method II after 45 and 60 days. However, both groups can be successfully used as a therapeutic strategy to rehabilitation of edentulous patients. Then, further experiments are needed to evaluate, in depth, the putative differential role of each surface treatment.

Bone healing in titanium and zirconia implants surface: a pilot study on the rabbit tibia

Introduction: Zirconia has been considered an alternative material to titanium for implant manufacturing, however the mechanisms regarding to bone healing in presence of zirconia implants remains poorly known. Objective: The objective of the investigation was to evaluate the bone healing surrounding titanium and zirconia implants in rabbits after 7, 14, 30, 45 and 60 days of implant placement through histological evaluation. Material and methods: Fifteen rabbits were used in this study and randomly subdivided into 5 groups, according to experimental periods. Titanium and zirconia implants were inserted into the right and left tibia, respectively. After healing periods of 7, 14, 30, 45 and 60 days, animals were euthanatized, the implants were removed and the samples were submitted to histological procedures. Results: Our histological results demonstrated similar bone healing surrounding titanium and zirconia implants after 7, 14 and 30 days after implant placement. After 45 days, a trend towards to earlier bone maturation was detected, remaining after 60 days. Inflammatory infiltrate, bone resorption and foreign body reaction were not observed in any periods and groups evaluated. Conclusion: Our findings demonstrated that zirconia and titanium presented a similar pattern of bone healing.

Elevação do seio maxilar com enxerto autógeno e instalação imediata de implante: quatro anos de acompanhamento / Maxillary sinus floor augmentation using autogenous bone graft and immediate implant installation: a case report with 4 years of follow-up

Introdução: a reabilitação das áreas posteriores da maxila, severamente reabsorvidas, com implantes osseointegráveis, são consideradas como um desafio ao cirurgião devido à reabsorção óssea e ao aumento na pneumatização do seio maxilar. Neste contexto, a elevação do seio maxilar utilizando substitutos ósseos se mostra como um procedimento efetivo para a reabilitação destas regiões. Objetivo e Métodos: O objetivo deste caso clínico foi relatar a elevação do seio maxilar com enxerto autógeno seguido pela instalação imediata de implante com acompanhamento de 4 anos. Além disso, as técnicas cirúrgicas bem como as indicações pertinentes foram abordadas em relação à utilização dos substitutos ósseos e instalação imediata dos implantes. Discussão e Conclusões: com base na literatura e nos resultados clínicos descritos neste relato de caso, esta técnica pode ser considerada como uma alternativa viável para a reabilitação de regiões posteriores da maxila severamente reabsorvidas com implantes osseointegráveis.

Introduction: implant-supported restorations in the atrophic posterior maxillary region has been considered as a challenge because of the alveolar bone resorption and increased pneumatization of the maxillary sinus. In this context, it is well established that maxillary sinus floor augmentation is an effective procedure for rehabilitation of these regions. Objective and Methods: the objective of this study was to describe a case report related to maxillary sinus floor augmentation procedure using autogenous bone graft followed by immediate implant installation with 4 years follow-up. Moreover, surgical techniques and the putative indications are discussed considering the applicability of bone substitutes and immediate implant installation. Results and Conclusion: based on the literature and clinical findings of this case report, this technique can be considered as a viable alternative for the implant-supported rehabilitation of the atrophic posterior maxillary regions.

Non-inflammatory destructive periodontal disease: a clinical, microbiological, immunological and genetic investigation

Periodontitis comprises a group of multifactorial diseases in which periodontopathogens accumulate in dental plaque and trigger host chronic inflammatory and immune responses against periodontal structures, which are determinant to the disease outcome. Although unusual cases of non-inflammatory destructive periodontal disease (NIDPD) are described, their pathogenesis remains unknown. A unique NIDPD case was investigated by clinical, microbiological, immunological and genetic tools. The patient, a non-smoking dental surgeon with excessive oral hygiene practice, presented a generalized bone resorption and tooth mobility, but not gingival inflammation or occlusion problems. No hematological, immunological or endocrine alterations were found. No periodontopathogens (A. actinomycetemcomitans, P. gingivalis, F. nucleatum and T. denticola) or viruses (HCMV, EBV-1 and HSV-1) were detected, along with levels of IL-1β and TNF-a in GCF compatible with healthy tissues. Conversely ALP, ACP and RANKL GCF levels were similar to diseased periodontal sites. Genetic investigation demonstrated that the patient carried some SNPs, as well HLA-DR4 (*0404) and HLA-B27 alleles, considered risk factors for bone loss. Then, a less vigorous and diminished frequency of toothbrushing was recommended to the patient, resulting in the arrest of alveolar bone loss, associated with the return of ALP, ACP and RANKL in GCF to normality levels. In conclusion, the unusual case presented here is compatible with the previous description of NIDPD, and the results that a possible combination of excessive force and frequency of mechanical stimulation with a potentially bone loss prone genotype could result in the alveolar bone loss seen in NIDPD.