Comparative Evaluation of Cell Viability Immediately After Osteotomy for Implants With Drills and Piezosurgery: Immunohistochemistry Analysis.

OBJECTIVE: To evaluate the effect of reusing drills and piezosurgery tips during implant osteotomy on immediate bone cell viability through immunohistochemical analysis. MATERIALS AND METHODS: Six male rabbits were divided into 2 groups and then divided into 5 subgroups-correspond to drills and tips used 10, 20, 30, 40, and 50 times, respectively. All animals received 10 osteotomies in each tibia, by use of the classic drilling procedure in one group (G1) and the piezosurgery device in the other group (G2). For immunohistochemical technique were utilized the osteoprotegerin, RANKL, osteocalcin, and caspase 3. Control procedures were performed by omitting the primary antibodies (negative control). RESULTS: Bone formation and resorption responses presented in more intense way during the piezosurgery. The expression of osteocalcin had become quite intense in piezosurgery groups, but with reduced immunostaining from the 30th osteotomy. The caspase 3 showed the viability of the osteoblast from the 20th osteotomy with piezosurgery and remained constant until the 50th. CONCLUSION: Piezosurgery provides greater osteoblastic cell viability than the system of conventional drilling. CLINICAL RELEVANCE: This study will provide data so that the authors can recycle the drills and tips for implant placement, thus enabling a better cell viability for osseointegration.

Healing process of autogenous bone graft in spontaneously hypertensive rats treated with losartan: an immunohistochemical and histomorphometric study.

PURPOSE: Hypertension is a major risk factor for cardiovascular diseases, which has been related to such changes as gradual bone loss and a decrease in bone mass index. The cellular and molecular mechanisms that involve hypertension and osteoporosis are not fully understood. Many patients have high blood pressure, controlled or uncontrolled, and may use at least 1 antihypertensive drug, and an understanding of the interference of hypertension with bone healing is very important when considering oral rehabilitation with implants and bone grafts. This study investigated the interference of hypertension in bone metabolism during the repair process of autogenous bone grafting and analyzed the influence of losartan, an antihypertensive drug and angiotensin II receptor antagonist, through histometric and immunohistochemical analyses by examining the protein expressions of osteocalcin, osteoprotegerin, receptor activator of nuclear factor-κB, receptor activator of nuclear factor-κB ligand, tartrate-resistant acid phosphatase, vascular endothelial growth factor, and platelet endothelial cell adhesion molecule. MATERIALS AND METHODS: The groups studied include 24 normotensive Wistar rats and 24 spontaneously hypertensive rats divided into groups treated and not treated with losartan. Rats were subjected to block bone graft surgery in the mandible and were sacrificed at 7, 14, and 28 days. RESULTS: Histometric analysis was performed to evaluate the amount of bone tissue formed at the interface of the recipient bed and bone graft. The total area of formed bone tissue was outlined and calculated. Immunohistochemical analysis was semi-quantitative and the significance of the differences between groups regarding the percentage of newly formed bone tissue interface and protein expression were determined by ANOVA analysis of variance and Kruskall-Wallis followed by Tukey test or Holm Sidak to detect differences between groups. The results were considered statistically significant when P<.05. CONCLUSION: The untreated hypertensive rats showed a delay in the repair of autogenous bone block grafts compared with untreated Wistar rats. Furthermore, the use of losartan for lowering blood pressure in these animals was shown to improve the healing process, despite not showing important statistical differences.

Block bone graft fixation (onlay): a modification of the surgical technique.

Several reconstructive methods of the alveolar ridge have been reported to make possible future rehabilitations with implants. Many of these methods come from studies done in animals, mainly rats. With this clinical practice based on scientific evidence, any experimental procedure that can be undertaken in real life is fundamental. Thus, any research that emulates as closely as possible those techniques used in humans are important. This study describes the modification of the technique for block bone graft fixation (onlay) in rats using the "lag screw"-type technique, normally used in clinical procedures for grafts in humans. The conclusion was that the execution of the described procedures minimizes interference of blood flow in the area because of the maintenance of the muscle insertion in the buckle aspect of the most anterior region of the mandible, providing better stability to the graft and better contact interface of the graft and receptor bed.

Piezosurgery applied to implant dentistry: clinical and biological aspects.

Piezosurgery is a new and modern technique of bone surgery in implantology. Selective cutting is possible for different ultrasonic frequencies acting only in hard tissues (mineralized), saving vital anatomical structures. With the piezoelectric osteotomy technique, receptor site preparation for implants, autogenous bone graft acquistition (particles and blocks), osteotomy for alveolar bone crest expansion, maxillary sinus lifting, and dental implant removal can be performed accurately and safely, providing excellent clinical and biological results, especially for osteocyte viability. The aim of this review was, through literature review, to present clinical applications of piezosurgery in implant dentistry and outline their advantages and disadvantages over conventional surgical systems. Moreover, this study addressed the biological aspects related to piezosurgery that differentiate it from those of bone tissue approaches. Overall, piezosurgery enables critical operations in simple and fully executable procedures; and effectively, areas that are difficult to access have less risk of soft tissue and neurovascular tissue damage via piezosurgery.

Osseointegrated implant fracture: causes and treatment.

Despite its high success rate, therapy with osseointegrated dental implants is not free of complications. Among the problems that may occur is fracture of implants, which, albeit a rare phenomenon, may lead to unpleasant clinical outcomes for the patient, as well as for the clinician. Thus, it is paramount to know the factors related to the biological processes involved in maintenance of osseointegration and biomechanics applied to dental implants to prevent such complications, as well as treatment options available to deal with the problem. Therefore, the objectives of this work were to investigate the literature to identify causative factors that may lead to fracture of dental implants and to discuss available procedures.

Utilization of surgical trepan for the obtainment of calvarial autogenous bone graft in maxillary reconstructions.

Maxillomandibular reconstructions are traditionally performed by means of autogenous bone grafts collected from intraoral donor areas and extraoral donor areas such as clavicle, iliac bone, rib, and tibia. The calvarial bone has been studied as an alternative donor area, with a low incidence of complications and minimal postoperative morbidity. Complications such as dural lacerations associated with cerebrospinal fluid leakage and extradural and subdural bleeding were minimized due to the use of surgical trepan, allowing the diploic layer delimitation before the osteotomy, preserving the internal calvarial cortical. The purpose of this article is to suggest a new technique for the obtainment of calvarial bone grafts with surgical trepan.

Comparative study of the mechanical resistance of 2 separate plates and 2 overlaid plates used in the fixation of the mandibular condyle: an in vitro study.

PURPOSE: The objective of this study was to carry out a comparative evaluation of the mechanical resistance of 2 rigid internal fixation techniques for fractures of the mandibular condyle using miniplates. MATERIALS AND METHODS: Forty polyurethane resin replicas of human hemimandibles were used. The hemimandibles were sectioned to simulate a high subcondylar fracture and then stabilized with 2 fixing techniques using 2.0-mm system plates and screws. The fixation techniques were 2 separate 4-hole plates with 8 screws, and 2 overlaid 4-hole plates with 4 screws. Each system was submitted to load tests, with the application of the load in mediolateral and anteroposterior directions in an Instron 4411 universal assay machine (Instron, Norwood, MA). RESULTS: Load values and peak displacement were measured. Means and standard deviations were evaluated by analysis of variance (P < .05) and Tukey tests, in which it was verified that the antero-posterior peak load value was affected by the arrangement of the plates on the models, although no differences were observed between the groups for the mediolateral peak load. The arrangement of the plates did not have any influence on peak displacement. Similarly, the final value of the mediolateral load was not affected by the arrangement of the plates on the model. CONCLUSION: The experimental model with 2 separate plates was statistically superior to the model with 2 overlaid plates only in relation to anteroposterior peak load. Despite showing superiority in mediolateral peak load and peak displacement, there was no statistical difference between the groups for these parameters.

Different surgical approaches for multiple fractured atrophic mandibles.

Atrophic edentulous mandible fractures in geriatric patients have low incidence but present several biological and biomechanical peculiarities that produce a nonunion rate of around 20%. Surgical extraoral approaches for internal fixation of these fractures can be transcervical or by one or two submandibular incisions. Two patients sustaining multiple fractures in atrophic edentulous mandible are presented: the first patient was 72-years-old, treated by two submandibular incisions, and the second was 81-years-old, treated by transcervical approach. We discuss the advantages and drawbacks of each approach and their indications according to the Luhr et al (1996) atrophy index.

Treatment of oral myiasis caused by Cochliomyia hominivorax: two cases treated with ivermectin.

The term myiasis is applied to the injurious action that larvae of certain diptera cause to the organism of vertebrate animals in the living or dead tissue in which they grow. Because of its great destructive potential, appropriate and preventative treatment are necessary. Among the sites of infestation, the human mouth is a common site, mainly in tropical countries. We present two cases of oral myiasis caused by Cochliomyia hominivorax spp. Ivermectin is an extremely effective semi-synthetic macrolides, in the treatment of this condition.

Radiographic and clinical evaluations of the zygomatico-maxillary complex fractures treated by 2. 0 miniplates system / Evaluaciones radiográficas y clínicas de fracturas del complejo cigomáticomaxilar tratadas por el sistema de mini placas 2. 0

The zygomaticomaxillary complex (ZMC) is the second highly incidental of facial fractures. According to the anatomical complexity, there are many reports in the literature about this trauma, mainly related to treatment for these fractures. With the purpose of evaluating clinically and radiographically the stability of unilateral zygomatic fractures treated by surgical reduction and fixed in two points by stable internal fixation, this research was proposed. Twenty patients with zygomatic fractures were evaluated and compared with twenty nonfractured patients. The results showed that there were no statistically significant differences among the obtained data, perimeter and area, of the treated and contra-lateral sides of the experimental group. When compared to the control group the differences were not statistically significant. We also performed a comparison of the distance between the nasal bone and zygomatic prominence in all groups the results were also satisfactory

Las fracturas del complejo cigomaticomaxilar son las segundas más frecuente del territorio facial. De acuerdo con la complejidad anatómica, existen muchos informes en la literatura sobre este trauma, principalmente relacionadas con el tratamiento de estas fracturas. El propósito de esta investigación fue evaluar clínica y radiográficamente la estabilidad de las fracturas cigomáticas unilaterales tratadas por reducción quirúrgica y fijadas en dos puntos por fijación interna estable. Veinte pacientes con fracturas cigomáticas fueron evaluados y comparados con veinte pacientes sin fracturas. En el grupo experimental, los resultados mostraron que no hubo diferencias estadísticamente significativas entre los datos obtenidos del perímetro y el área de los lados tratados y contralaterales. Al comparar estos datos con el grupo de control las diferencias no fueron estadísticamente significativas. También se realizó una comparación de la distancia entre el hueso nasal y la prominencia cigomática en todos los grupos, estos resultados también fueron satisfactorios

Tracionamento ortodôntico-cirúrgico para caninos superiores impactados: revisão crítica e sugestão de protocolo / Surgical-orthodontic traction for impacted maxillary canines: a critical review and suggested protocolc

Maxillary canine impaction is a common occurrence, especially in the palate, despite sufficient space in the arch for tooth alignment. A proper approach requires knowledge of different specialties of dentistry, such as orthodontics, surgery, radiology, and periodontology, which are generally not centered on a single professional. The causes for canine impaction may be either generalized or localized, and the diagnosis should be made through specific clinical and radiographic examination. The prognosis of surgical–orthodontic treatment depends on the position of the canine in relation to the neighboring teeth and height of the alveolar process, in addition to careful surgical technique, considering that there are risks involved, such as ankylosis, loss of tooth vitality, root resorption of the involved tooth and adjacent teeth, and damage to supporting tissues. Given the important role played by impacted maxillary canines, their traction is the treatment of choice in orthodontically treated patients. The present study reviews the literature on important factors to be considered when approaching impacted canines, such as therapeutic possibilities, their advantages and disadvantages.

A impactação de caninos superiores é uma ocorrência freqüente, especialmente na região palatina, ainda que na presença de espaço suficiente para seu alinhamento na arcada. A abordagem exige conhecimentos de diferentes especialidades da odontologia, tais como a ortodontia, cirurgia, radiologia e periodontia e que, em geral, não se centram em um único profissional. Pode ser causada por fatores de ordem geral ou local, sendo que seu diagnóstico deve ser realizado por meio de exames clínico e radiográfico específicos. O prognóstico do tratamento ortodôntico–cirúrgico ira depender da posição do canino em relação aos dentes vizinhos e da sua altura no processo alveolar, além de técnica cirúrgica cuidadosa, haja vista que envolve riscos, como: anquilose, desvitalização, reabsorção radicular do dente envolvido e dos dentes adjacentes e dano aos tecidos de suporte. Em virtude das importantes funções desempenhadas pelos caninos inclusos superiores, o seu aproveitamento através do tracionamento é o tratamento de eleição nos pacientes assistidos ortodonticamente. O presente trabalho traz uma revisão bibliográfica acerca de importantes fatores a serem considerados na abordagem dos caninos impactados, tais como as possibilidades terapêuticas, suas vantagens e desvantagens.

Fasceíte necrotizante em região maxilofaxial: relato de caso / Necrotizing fasciitis in maxilofacial region: case report

A fasceíte necrotizante de cabeça e pescoço é um processo infeccioso incomum, de origem polimicrobiana, que se caracteriza por extensa necrose e formação gasosa no tecido subcutâneo e fáscia superficial, levando a quadros de toxicidade sistêmica podendo ser fatal. Apesar de pouco frequente, essa condição, na sua grande maioria, evolui como complicação de infecções ou tratamentos dentários, o que aumenta a responsabilidade do cirurgião-dentista frente ao diagnóstico precoce e ao tratamento adequado.

Necrotizing Fasciitis of head and neck is an uncommon infectious process of polymicrobial origin characterized by extensive necrosis and gas formation in the subcutaneous tissue and superficial fascia, leading to systemic toxicity, multisystem organ failure and eventual death. Although little frequent, this pathology it evolves with a complication of infection or dental treatment, what it increases the responsibility of the dentist front the early diagnosis and the adequate treatment with antibiotics, surgery debridament of all necrotic tissue, culture and support therapy.

Acessos cirúrgicos a articulação temporomandibular: revisão de literatura / Surgical approaches to the temporomandibular joint: review

A escolha do acesso cirúrgico para as afecções que atingema região pré-auricular tem sido motivo de bastante discussãona literatura. Acessos pré-auriculares vêm sendo usados coma observância de alta taxa de sucesso e, durante a históriada cirurgia, diversas modificações nesta abordagem foramrealizadas com o objetivo de redução das sequelas irreversíveis,sobretudo em fraturas condilares como paralisias e cicatrizesfaciais. As opiniões vão desde a indicação do tratamento cirúrgicoa todas as fraturas, até a convicção de que nenhuma fraturadesse segmento ósseo deva ser abordada cirurgicamente.Portanto, o presente estudo reveste-se de relevância, uma vezque propõe alertar os cirurgiões quanto aos cuidados diantedas estruturas anatômicas envolvidas nestes acessos cirúrgicosalém de descrever, buscando uma comparação entre eles, asvantagens dos mesmos por meio de uma revisão de literatura queabrangerá desde os extensos acessos de Bellinger (1940) e Al-Kayat (1979) que promovem uma ampla visualização do campooperatório até acessos modificados e cada vez menores comoo Endaural (2001) que não só possibilita um campo satisfatóriocomo manutenção da estética do paciente, sem qualquer sinalde cicatriz.

Análise do processo de reparo de enxerto ósseo autógeno em mandíbula de ratos espontaneamente hipertensos (SHR) não tratados e tratados com losartan: estudo imunoistoquímico e histomorfométrico / Bone healing analysis of the autogenous onlay bone graft in mandible of spontaneous hypertensive rats (SHR) non treated and treated by losartan: histological and immunohistochemical study

A hipertensão arterial é o maior fator de risco para doenças cardiovasculares, caracterizada por uma disfunção endotelial, alteração no controle do crescimento das células vasculares e morte celular. Alterações como gradual perda óssea e diminuição no índice de massa óssea corpórea têm sido fortemente relacionadas com hipertensão, sendo que os mecanismos celulares e moleculares que envolvem a hipertensão e osteoporose não são compreendidos completamente como um todo. Objetivos: O presente projeto teve por objetivo estudar a interferência da hipertensão essencial no metabolismo ósseo durante o processo de reparo de enxerto ósseo autógeno, bem como analisar a influência do losartan, um medicamento anti-hipertensivo antagonista dos receptores de angiotensina, analisando a expressão das proteínas OC, OPG, RANK, RANKL, TRAP, VEGF e PECAM através da técnica de imunoistoquímica. Além disso, este projeto pretendeu realizar a análise histomorfométrica do tecido ósseo formado durante o processo de reparo. Material e métodos: Os grupos estudados compreenderam 24 ratos normotensos Wistar e 24 ratos espontaneamente hipertensos, divididos em grupos não tratados e tratados com Losartan, submetidos a procedimentos cirúrgicos para realização de enxertos ósseos em bloco na mandíbula, nos períodos de 7, 14 e 28 dias. Conclusão: Conclui-se que os animais SHR apresentam atraso no processo de reparo de enxertos ósseos autógeno em bloco quando comparados aos animais Wistar, e que o uso do losartan para redução da pressão arterial nestes animais demonstrou melhorar o processo cicatricial, apesar de não haverem diferenças estatísticas significantes.

Hypertension is the major risk factor to coronary diseases characterized by endothelial disfunction, alterations on the growing of vascular cell and death cell. Alterations like continuous bone loss and lower body mass index have been strongly connected with hypertension, althought the mollecular and cellular mechanisms wich involve the hypertension and osteoporosis are not completely understood. Objectives: This study has the objective to observe the high blood pressure interference in the osseous metabolism during the bone healing of autogenous bone graft and carry out analysis about the administration of losartan, a receptor angiotensin antagonist by OC, OPG, RANK, RANKL, TRAP, VEGF and PECAM expressions by immunohistochemical technique and hystological analysis of the bone tissue. Material and methods: The groups studied were 24 normotensive rats Wistar and 24 spontaneous hypertensive rats dealed out non treated and treated groups by losartan. Surgical procedures were carried out and an onlay bone grat were fixed on the mandible and the animmals were sacrified on the 7, 14 and 28 days. Conclusion: we conclued that the SHR has a late bone healing process when comparing with Wistar group and the losartan administration to reduce the blood pressure has the potential to become better the bone graft healing, althought significant estatistical differences not exist.

Acidentes e complicações em cirurgia ortognática / Accidents and complications in orthognathic surgery

Apesar de não existirem dados estatísticos quantitativos referentes às cirurgias ortognáticas realizadas no Brasil, é de consenso comum que a demanda por tal procedimento tem aumentado, principalmente devido ao maior número de centros formadores de cirurgiões bucomaxilofaciais e maior aceitação pelos ortodontistas. A cirurgia ortognática, como qualquer procedimento cirúrgico, apresenta riscos de acidentes e complicações. O diagnóstico e compreensão destes transtornos consistem no primeiro passo para adoção de um tratamento adequado. Assim, o presente trabalho pretende apresentar aos cirurgiões bucomaxilofaciais e ortodontistas os acidentes e complicações passíveis de ocorrerem nas diferentes fases da realização deste procedimento.

Uso dos inibidores seletivos da COX-2 na odontologia / Use of the COX-2 sécific inhibitor in dentistry

O objetivo do presente estudo foi determinar a reprodutibilidade geométrica de um método de exames radiográficos padronizados (PerioSmart ). Foram selecionados 12 indivíduos com periodontite agressiva, participantes de um ensaio clínico que comparava terapias periodontais. Os exames foram repetidos devido à ocorrência de problemas de processamento químico, resultando em uma amostra de 17 pares. Foram utilizados ilmes radiográicos Insight – Kodak, com 0,6 segundos de exposição e processamento automático, sendo feita digitalização com 400 dpi – 8 bits e análise no programa Adobe PhotoShop 7.0. Distâncias horizontais foram medidas dos pontos mais distais e mesiais das superfícies proximais da coroa do dente e verticais da junção amelo-cementária até o ponto mais coronal de uma das cúspides, ambas por um examinador calibrado. Foram analisados 44 pares de dentes, comparando as distâncias por meio do teste t pareado (alfa = 5%). Não foram observadas diferenças signiicativas nas distorções totais horizontal e vertical (0,11 mm, IC 95% -0,48 – 0,69; e 0,50 mm, IC 95% -0,03 – 1,03 mm, respectivamente). Quando analisados molares e pré-molares separadamente, não houve distorções signiicativas. Não houve diferenças signiicativas também entre as distorções horizontal e vertical. No arco superior, foi observada uma distorção horizontal signiicativa (0,25 mm, IC 95% 0,01 – 0,50), porém a distorção vertical não foi signiicativa (0,30 mm, IC 95% -0,20 – 0,80). No arco inferior, não foram detectadas distorções signiicativas. Concluiu-se, portanto, que o método avaliado é reproduzível e gera uma distorção geométrica limitada, o que sugere possibilidade de uso em pesquisas clínicas.

The non steroids anti inlammatory and analgesic medicines are among the most used medicines by population. The use of these medicines in a chronic and acute way promotes some undesirable effects such as gastro intestinal disturbs, skin lesions, adverse kidney effects and other side effects. So the pharmaceutical industries started developing analgesic and anti inlammatory agents presenting selectivity for the COX-2 inhibition, the so called coxibs, in order to achieve the clinical effectiveness with reduced risks of gastro intestinal effects and other side effects. But these drugs have presented some other adverse effects such as cardiac alterations which may limit their use demonstrating that the coxib use on the regular basis in dentistry is not justiied with the exception of patients with medical history of conirmed gastrointestinal disturbs.