Immediate autogenous extracted tooth as a grafting material for fresh socket preservation: a systematic review / Diente autógeno de extracción inmediata como material de injerto para la conservación de alvéolos frescos: una revisión sistemática

Objectives: To evaluate the use of extracted autogenous teeth for socket preservation after tooth extraction. Material and Methods: Cochrane, Scopus, and PubMed databases search was conducted to identify human clinical studies reporting the clinical, radiographic and/or histological outcomes of socket preservation techniques with autogenous extracted tooth Only studies published in English language in the last 10 years were included in the study. Results: In total, 82 articles were identified. Five articles were included in the review. They included 58 teeth that were prepared as a graft for socket preservation. The grafts derived from autogenous teeth were presented in three forms: particles, blocks and powder. The mean bone loss ranged from 0.28 mm to 0.41mm in height and 0.15 mm in width. Conclusion: Immediate autogenous extracted tooth as a grafting material for fresh socket preservation is promising for future daily clinical practice. More clinical comparative studies are needed.

Objetivo: Evaluar el uso de dientes extraídos autógenos para la preservación del alveolo tras la extracción dental.Material y Métodos: Se realizó una búsqueda en las bases de datos Cochrane, Scopus y PubMed para identificar estudios clínicos en humanos que informaban los resultados clínicos, radiográficos y / o histológicos de las técnicas de preservación de alveolos con dientes extraídos autógenos. Solo se incluyeron estudios publicados en inglés en los últimos 10 años. Resultados: En total se identificaron 82 artículos. Se incluyeron cinco artículos en la revisión. Incluyeron 58 dientes que se prepararon como injerto para la preservación del alveolo. Los injertos derivados de dientes autógenos se presentaron en tres formas: partículas, bloques y polvo. La pérdida ósea media osciló entre 0,28 mm y 0,41 mm de altura y 0,15 mm de ancho. Conclusión: El diente autógeno extraído de forma inmediata utilizado como material de injerto para la conservación del alveolo fresco es prometedor para la práctica clínica diaria futura. Se necesitan más estudios clínicos comparativos.

Efficacy of two barrier membranes and deproteinized bovine bone mineral on bone regeneration in extraction sockets: A microcomputed tomographic study in dogs / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model.@*METHODS@#The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group.@*RESULTS@#The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05).@*CONCLUSION@#mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.

Transplante dentário autógeno: revisão de literatura e relato de caso clínico / Autogenous dental transplantation: literature review and clinical case report

Objetivo: o transplante dentário é uma técnica cirúrgica que consiste na movimentação cirúrgica de um dente, podendo ser vital ou tratado endodonticamente, o qual é submetido a uma avulsão do seu local de origem e implantado em outro alvéolo. Relato de caso: paciente do sexo masculino, 18 anos, normossistêmico, buscou atendimento no Serviço de Cirurgia e Traumatologia Bucomaxilofacial da Pontífica Universidade Católica do Rio Grande do Sul (PUCRS) apresentando cárie no dente 26. O plano de tratamento consistiu em realizar um autotransplante do dente 28 para o alvéolo do dente 26. Após 8 meses do transplante, o dente apresentava em boas condições periodontais avaliadas clinicamente e em exame radiográfico. Considerações finais: o transplante dentário autógeno pode ser uma opção viável para a substituição de molares ausentes ou com cáries extensas, como mostrado no presente caso clínico. (AU)

Objective: Dental transplantation is a surgical technique that consists of the surgical movement of an either vital or endodontically treated tooth, which is subjected to an avulsion from its place of origin and implanted in another socket. Case report: An 18-year-old male patient, normosystemic, attended the Oral and Maxillofacial Traumatology Surgery Service of PUCRS presenting a decayed tooth 26. The treatment plan consisted of the autotransplantation of tooth 28 to the alveolus of tooth 26. Eight months after the transplantation, the tooth presented satisfactory periodontal conditions by clinical and radiographic assessments. Final considerations: The autogenous dental transplantation may be a viable option for replacing absent molars or with extensive caries, as shown in the present clinical case. (AU)

Mandibular trabecular structures in alveolar ridge preservation using different grafting materials after tooth extraction / Estructura trabecular mandibular en preservación de reborde alveolar utilizando diferentes materiales de injerto después de la exodoncia

The aim was to describe the star volume analysis in ridge preservation using different grafting materials. Bilateral extraction of the first mandibular molars of sixteen male rabbits was performed, divided at random into four groups (n= 4 in each group) according to graft, using: blood clot (G1), xenograft (G2), pure phase beta-tricalcium phosphate (G3) and biphasic calcium phosphate (60 % HA / 40 % beta-TCP) (G4). Rabbits were euthanized at 4, 6, or 8 wk post-extraction; the trabecular bone structures was evaluated by star volume analysis. The Levene test was used to analyze variance, as was the independent sample t-test. A P-value of < 0.001 was used to establish a statistically significant. The star volume analysis of the mandibular trabecula shows that the marrow space star volume (V*m.space) was higher than the trabecular star volume (V*tr). At 6-week post-extraction, new trabecular bone was evident. At 8-week post-extraction V*tr increase in all groups and the V*m.space diminish, suggesting coarsening of the internal architecture. In G2, some trabecular bone was observed in the central region. In G3, most of the socket regions were occupied by newly formed and loose trabecular bone and in the G4, the sockets were almost entirely filled with trabecular bone. Star volume analysis is adequate to analysis of bone patterns formation using bone substitutes.

El objetivo de esta investigación fue describir el volumen estrella en preservación alveolar utilizando diferentes injertos óseos. La exodoncia bilateral del primer molar mandibular de 16 conejos machos fue realizada, dividiéndolos en 4 grupos (n= 4 en cada grupo) de acuerdo al injerto utilizado, siendo: coágulo sanguíneo (G1), xenoinjerto (G2), beta-tricalcio fosfato puro (G3) y fosfato de calcio bifásico (60 % HA / 40 % beta-TCP) (G4). Los conejos fueron sometidos a eutanasia a las 4, 6 u 8 semanas post exodoncia; el trabeculado óseo fue evaluado por medio del volumen estrella. La prueba de Levene fue utilizado para el análisis de varianza y luego la prueba t-test para muestras independientes. El valor de P menor a 0.001 fue establecido como significancia estadística. El análisis del volumen estrella del trabeculado mostró que el espacio medular de volumen estrella (V*m.space) fue mayor que trabeculado (V*tr). A 6 semanas post exodoncia, nuevo trabeculado óseo fue evidente. A las 8 semanas post exodoncia V*tr aumenta en todos los grupos y el V*m.space disminuye, sugiriendo un engrosamiento de la arquitectura interna. En el grupo G2, algún trabeculado óseo fue observado en la región central. En el G3, la mayoría del alveolo fue ocupado por nuevo hueso y perdió trabeculado óseo y en G4, el alveolo fue ocupado casi enteramente por hueso trabecular. El análisis de volumen estrella es adecuado para analizar el modelo de formación ósea utilizando sustitutos óseos.

Implante imediato com provisionalização imediata através de cicatrizador multifuncional de PEEK / Immediate implant placement and provisionalization using a multifunctional PEEK healing abutment

Este artigo teve por objetivo apresentar um caso clínico cuja prótese provisória utilizou um componente protético multifuncional de PEEK. Este é um polímero biocompatível personalizável e de boa aderência às resinas. O caso descrito é um implante imediato com carga imediata na região do 21. Foi realizado um approach palatino do implante, preenchimento do gap vestibular com um enxerto aloplástico (Nanosynt), um provisório imediato utilizando um componente provisório multifuncional de PEEK e um dente de estoque. O caso foi acompanhado até a fase de confecção da prótese defi nitiva, na qual foi verifi cada a arquitetura dos tecidos peri-implantares quanto à saúde e manutenção. Na Implantodontia contemporânea, o PEEK é a opção biológico-funcional com melhor custo-benefício nos casos de implantes colocados e carregados imediatamente.

The aim of this article was to present a clinical case where the provisional restoration was fabricated over a multifunctional PEEK healing abutment. This biocompatible polymer can be customized and has excellent bond strength to resin composites. A dental implant was loaded at the region of tooth 21. After a palatal approach for implant placement, the buccal gap was fi lled with an alloplastic graft (Nanosynt). Then, the immediate restoration was fabricated with the multifunctional PEEK and an acrylic tooth form. At the delivery of the defi nitive restoration, the peri-implant soft tissue health and architecture were preserved. In the contemporary implant dentistry, PEEK abutments provide the best biological and functional option with a signifi cant cost-benefi t ratio for cases of immediate implant loading

Changes in morphology of alveolar buccal walls following atraumatic internal root fragmentation / Cambios en la morfología de las paredes alveolares bucales después de fragmentación radicular interna atraumática

The buccal alveolar wall represents the most important structure to provide shape and volume of the alveolous following tooth extraction. The aim of the study was the evaluation of buccal alveolar bone structures following minimally invasive surgery. In 15 patients (3 male, 12 female), aged 20­67 years, 3 central incisors, 5 lateral incisors, and 7 bicuspids were removed using flapless enucleation. The enucleation comprised endoscopically assisted mesiodistal root sectioning with inward fragmentation of the oral and apical parts followed by internal reduction of the buccal root lamella. Buccal bone height before extraction was 10.61 mm, following extraction 10.50 mm. Crestal width of the buccal bone plate was 1.11 mm before and 1.40 mm after tooth removal. Apical buccal bone width before was 0.66 mm and after extraction 0.40 mm. Gingival height was 13.58 mm before and 13.56 mm following extraction. Following transalveolar enucleation, the buccal alveolar bone wall remains unchanged concerning height and crestal width.

La pared alveolar bucal representa la estructura más importante para proveer la forma y el volumen de los alveólos dentales posterior a la extracción dental. El objetivo del estudio fue evaluar las estructuras de hueso alveolar bucal después de la cirugía mínimamente invasiva. En 15 pacientes (3 hombres, 12 mujeres), con edades entre 20 a 67 años, 3 incisivos centrales, 5 incisivos laterales y 7 premolares fueron removidos utilizando enucleación sin colgajo. La enucleación comprende el seccionamiento mesio-distal de la raíz dental endoscópicamente asisitido a través de fragmentación interna de la porción lingual y apical radicular y posteriomente una reducción interna de la lamela de raíz bucal. La altura ósea bucal antes de la extracción fue 10,61 mm y después de la extracción fue 10,50 mm. La anchura de la cresta ósea bucal fue 1,11 mm y 1,40 mm después de la extracción del diente. El grosor del hueso apical antes de la extracción fue 0,66 mm y 0,40 mm después de la extracción. La altura gingival fue 13,58 mm antes de la extracción y 13,56 mm después de la extracción. Después de la enucleación transalveolar, la pared del hueso alveolar bucal se mantiene sin cambios en relación con la altura y del grosor del reborde alveolar.

Alveolar ridge conservation by early bone formation after tooth extraction in rabbits: a histomorphological study / Conservación de la cresta alveolar por formación ósea temprana después de la extracción dentaria en conejos: un estudio histomorfológico

Alveolar ridge volume loss is an irreversible process. To prevent this physiological event, which typically result in significant local anatomical changes in both the horizontal and the vertical dimension, some strategies are indicated to minimize the loss of ridge volume that typically follows tooth extraction. The purpose of this study was to evaluate if three different bone grafts could promote new bone formation in the alveolar socket following tooth extraction for the alveolar ridge conservation. First mandibular molars of male adults rabbits were extracted and the extraction sockets were randomly treated with three different bone grafts, one xenograft and two alloplastic grafts, and a group that received no treatment (blood clot). The extraction sockets of selected rabbits from each group were evaluated at 4, 6, or 8-week post-extraction. The results indicated that the extraction sockets treated with alloplastic graft (biphasic calcium phosphate) exhibited lamellar bone formation (6.5%) as early as four weeks after the extraction was performed. Moreover, the degree of new bone formation was significantly higher (P<0.05) in the extraction sockets treated with biphasic calcium phosphate at 8-week post-extraction than that in the other study groups. In this study, we demonstrated that the proposed animal model is useful to evaluate the bone formation after tooth extraction and the alveolar ridge conservation is feasible. The new bone formation and alveolar ridge preservation with bone graft after extraction of molar teeth, could result in the maintenance of sufficient bone volume to place an implant in an ideal restorative position without the need for ancillary implant site development procedures.

La pérdida de volumen cresta alveolar, es un proceso irreversible. Para evitar este evento fisiológico, que típicamente resulta en cambios anatómicos locales significativos, tanto en la dimensión horizontal y vertical, existen algunos procedimienos para reducir al mínimo la pérdida de volumen óseo que sigue típicamente a la extracción del diente. El propósito de este estudio fue evaluar si tres injertos óseos diferentes podrían promover la formación de hueso en el alveolo tras la extracción del diente para la conservación de la cresta alveolar. Los primeros molares mandibulares de conejos machos adultos fueron extraídos y los alvéolos post extracción fueron rellenados aleatoriamente con tres injertos óseos diferentes, uno de xenoinjerto y dos injertos aloplásticos, más un grupo que no recibió tratamiento (coágulo de sangre). Los alvéolos post extracción en los conejos seleccionados de cada grupo fueron evaluados a las 4, 6, o 8 semanas post-extracción. Los resultados indicaron que los alvéolos tratados con injerto aloplástico mostraron formación de hueso lamelar (6,5%) ya a las 4 semanas post extracción. Por otra parte, el grado de formación de hueso nuevo fue significativamente mayor (P<0,05) en los alvéolos tratados con fosfato de calcio bifásico en 8 semanas post-extracción que en los otros grupos de estudio. Demostramos que el modelo animal propuesto es útil para evaluar la formación de hueso después de la extracción del diente, y la conservación de la cresta alveolar es factible. La nueva formación de hueso y la preservación del reborde alveolar con injerto óseo después de la extracción de los dientes molares, podrían mantener un volumen de hueso suficiente para colocar un implante en una posición ideal para la posterior restauración, sin la necesidad de procedimientos de quirúrgicos anexos.

Seleção do diâmetro do implante em alvéolos pós-exodontia: uma nova abordagem / Diameter selection of implants placed in extraction sockets: a new approach

A instalação de implantes em alvéolos de extração pode ser considerado um procedimento desafiador, devido ao risco de remodelação óssea e às consequentes alterações gengivais. Objetivo: o presente estudo tem como objetivo propor um protocolo de seleção do diâmetro de implantes osseointegráveis em alvéolos pós-extração na região anterossuperior, baseado na medida vestibulopalatina do alvéolo, permitindo a formação de um espaço entre o implante e a porção externa da parede óssea vestibular, de 3mm, que deverá ser preenchido com biomaterial ou com ósseo autógeno, aumentando a previsibilidade de resultados em longo prazo...

Implant placement in extraction sockets is a challenging procedure, since it offers risks of bone remodeling and, as a consequent, gingival alterations. Objective: This study aims at proposing a protocol for selecting the diameter of osseointegrated implants placed in extraction sockets in the anterosuperior region. This protocol is based on the buccal palatal dimension of the socket and allows a 3-mm gap to form between the implant and the outer surface of the buccal bone wall.Such gap must be filled with biomaterial or autograft so as to increase the predictability of long-term results...

Utilización de sulfato de calcio hemihidratado como material de relleno y barrera en un alveolo post-exodoncia: Una observación clínica, tomográfica e histológica comparativa a 4 meses antes de la colocación de implantes / Use of calcium sulfate hemihydrate as a filler and barrier in a post-extraction alveolus. A clinical, tomographic and histological comparative observation to 4 months before implant placement

Evaluar y comparar de forma clínica, tomográfica e histológica el proceso de reparación ósea y la conservación del reborde alveolar en dos alveolos post-extracción de paredes intactas, con y sin la utilización de un material sustituto óseo regenerativo a base de sulfato de calcio hemihidratado como relleno y barrera, antes de la colocación de implantes a cuatro meses.

To evaluate and compare clinically, tomographic and histological the bone repair process and the preservation of the alveolar walls of two sockets intact, with and without the use of a bone substitute material based regenerative calcium sulfate hemihydrate as a filler and barrier before implant placement to four months.

Filling of extraction sockets of feline maxillary canine teeth with autogenous bone or bioactive glass

PURPOSE: To evaluate bone healing in the extraction socket of the feline maxillary canine tooth after grafting. METHODS: Eighteen adult cats were submitted to unilateral extraction of maxillary canine tooth and divided into three groups. In group 1 (n=6), control, the extraction socket was left empty. In group 2 (n=6), the extraction socket was filled with autogenous cancellous bone from the iliac crest and in group 3 (n=6), with bioactive glass particulate material. Cats were euthanized at four weeks postoperative. RESULTS: The radiographic examinations performed four weeks after surgery showed that in all groups the healing process converged to a radiopacity similar to that observed in the surrounding bones. Histological examination showed formation of woven bone within the extraction socket. The percentage of newly formed bone within the extraction socket, measured by the histometry, showed no statistically significant difference among the values of the three groups (Kruskal-Wallis'test p>0.05) (group 1: 63.96 ± 5.85, group 2: 66.84 ± 11.67, group 3: 59.28 ± 15.50). CONCLUSION: The bone regeneration observed in the extraction sockets filled with autogenous cancellous bone or bioactive glass was similar to that observed in the control sites, given an observation period of four weeks after extraction of the maxillary canine tooth.

Autotransplantation of a Mandibular Third Molar: A Case Report with 5 Years of Follow-up

This paper describes the autologous transplantation of a mandibular right third molar to replace the residual roots of the second molar in the same quadrant, preserving function and aesthetics. A 5-year clinical and radiographic follow-up was undertaken. After transplantation, the donor tooth received endodontic treatment and placement of calcium hydroxide, which was periodically replaced every 3 months until the filling of the root canals, totalizing a period of 1-year, when apical closure was confirmed. The tooth was in perfect functional and aesthetic conditions 5 years after beginning of treatment. Autotransplantation is a feasible option for replacing missing teeth when a donor tooth is available. The autotransplantation of a right mandibular third molar with compromised function and aesthetics to replace the residual roots resulting from coronal destruction due to extensive carious lesion of the second molar in the same quadrant was a viable treatment alternative.

O objetivo deste trabalho foi descrever o transplante autógeno de um terceiro molar inferior direito para substituir as raízes residuais do segundo molar no mesmo quadrante, preservando a função e a estética. Foi realizado acompanhamento clínico e radiográfico por 5 anos. Após o transplante, o dente doador recebeu tratamento endodôntico e colocação de hidróxido de cálcio, o qual foi substituído periodicamente a cada 3 meses, até a obturação dos canais radiculares, totalizando período de 1 ano quando então, o fechamento apical foi confirmado. O dente encontra-se em perfeitas condições funcionais e estéticas após 5 anos do início do tratamento. O autotransplante é uma opção viável para a substituição de dentes perdidos quando um dente doador está disponível. O autotransplante de um terceiro molar inferior direito com comprometimento estético e funcional afim de substituir raízes residuais (resultado de um processo cariogênio extenso) de um segundo molar do mesmo quadrante foi um tratamento alternativo viável.

Eficácia na remoção da necrose óssea térmica: realizada por implantes osseointegráveis com câmaras coletoras / Removal effectiveness of thermal osteonecrosis: performed by osseointegrated implants with collecting chambers

Durante a confecção do alvéolo, promove-se o aumento da temperatura da broca devido à fricção, aquecendo o tecido ósseo adjacente e seus componentes celulares, podendo provocar a Necrose Óssea Térmica. A necrose óssea térmica deteriora a porção orgânica do tecido ósseo (tanto matriz óssea como as células), bem como as células diferenciadas e indiferenciadas presentes na circulação sanguínea e medula óssea local. Alguns trabalhos demonstraram que o aquecimento ósseo acima de 47oC por 1 minuto provoca tal fenômeno. Atualmente existem variações na técnica de perfuração com objetivo de diminuir o grau de aquecimento e aumentar as taxas de sucesso dos tratamentos reabilitadores. Sabemos que nem todos os profissionais são cautelosos em utilizar materiais de qualidade e que mesmo os materiais com qualidade, após repetido uso, perdem a eficácia. Seria ideal que o implante osseointegrável gerenciasse a remoção destas áreas de necrose óssea térmica, independentemente da execução correta da técnica de perfuração e da qualidade das brocas. Com isso, garantiríamos que o tecido ósseo poderia se reparar ao redor dos implantes da melhor maneira possível. Neste trabalho avaliamos a eficácia de 3 modelos de implante com câmaras coletoras funcionais diferentes, em tecido ósseo de minipig. O implante com câmara coletora interna demonstrou-se 37,22% mais eficaz que o implante com câmaras externas e 3 arestas cortantes, quando os alvéolos eram confeccionados sem irrigação e com brocas desgastadas. O implante com câmaras coletoras externas e 4 arestas também demonstrou-se eficaz, porém manteve 83,75% das células viáveis enquanto que no grupo com câmaras internas este resultado foi de 91,39%.

The manufacture of the alveolus can increase the temperature of the drill due to friction heating the adjacent bone tissue and its cellular components, this phenomenon is known by thermal osteonecrosis. The thermal osteonecrosis deteriorates the organic portion of bone (bone matrix and cells), as well as undifferentiated and differentiated cells circulating in the blood and bone marrow. Some studies have demonstrated that bone heating above 47oC for 1 minute causes this phenomenon. Currently there are variations in drilling technique aiming to reduce the heating degree and increase the success rates of rehabilitation treatments. We know that not all professionals are cautious of using quality materials and even the materials with quality after repeated use, lose their effectiveness. Would be ideal that implants manages and removes these areas with thermal osteonecrosis, regardless of the technique of implementing the drilling and the quality of drills. With this, we ensure that bone tissue could possibly repair around implants in the best way. In this study we evaluated the efficacy of 3 implant models with different functional collecting chambers in minipigs bone tissue. The implant with internal collection chamber proved to be 37.22% more effective than the implant with external chambers and three sharp edges, when the alveolus were manufactured without irrigation and uncut drills. The implant with external collecting chambers and four sharp edges also showed an effective but 83.75% of the cells remained viable while in the group with internal chambers this result was 91.39%.

Células-tronco mesenquimais: Isolamento e caracterização de populações derivadas de alvéolo dental humano e identificação e caracterização de populações de polpas dentais de camundongos / Mesenchymal stem cells: Isolation and characterization of populations derived from human dental alveolus and identification and characterization of populations from mouse dental pulp

Há um grande interesse no estudo de células-tronco em função de sua capacidade de auto-renovação e plasticidade. Estas características capacitam as células-tronco a produzirem células de diferentes linhagens que participam ativamente do processo de homeostase, da resposta à injúria e da regeneração e reparação tecidual. A polpa dental é o tecido mais estudado na Odontologia em relação a células-tronco, mas diversos estudos já mostraram a presença dessas células também na região periodontal. É importante salientar, que dependendo de sua origem, as células-tronco apresentam comportamentos diversos, especialmente no que tange ao transplante in vivo. Além disso, os microambientes onde as células-tronco residem (nichos), têm um papel fundamental no comportamento das mesmas, pois controlam aspectos essenciais como o estado de indiferenciação e a auto-renovação. Esse projeto de pesquisa teve como objetivos duas análises distintas. Na primeira, verificar se existem células-tronco mesenquimais derivadas da curetagem do alvéolo dental humano após extrações dentais. Na segunda, analisar o nicho de células-tronco nas polpas dentais de camundongos. Em comum, as duas análises se basearam no uso de marcadores previamente utilizados na literatura para o estudo de células-tronco. Como não existem marcadores únicos e específicos para a identificação dessas células, diferentes combinações desses marcadores entre si e de técnicas laboratoriais foram empregadas. No primeiro estudo, após o isolamento das células, deu-se especial atenção à sua caracterização, que foi realizada através de ensaios que avaliaram propriedades e comportamentos que sabidamente ocorrem em células-tronco. Já na segunda parte desse estudo, utilizamos a polpa dental de camundongos para a análise in vivo de nichos. Em camundongos, a localização do nicho responsável pelo crescimento continuo dos incisivos é conhecida. De uma maneira geral, nossos resultados demonstram que: 1) É possível isolar células-tronco/progenitoras a partir de tecidos curetados de alvéolo dental após extrações dentárias. Esse fato é inédito e abre novas perspectivas em termos de oportunidade de coleta e futura aplicação clínica. 2) É possível observar a diversidade populacional nas células que formam o nicho de células-tronco em polpa dental de camundongos, e através de uma organização hierárquica, propusemos um modelo para este nicho. Esse modelo servirá de base para estudos subsequentes que visem avaliar o comportamento das células que formam o nicho, quando isoladas das demais, e abrirá possibilidade para análises em outros tecidos dentais e não dentais.

There is great interest in the study of stem cells due to their ability to produce mature cells of different lineages that participate actively in the process of homeostasis, injury response, regeneration and tissue repair. The dental pulp is the most studied tissue in dentistry, but several studies have shown the presence of these cells in the periodontal tissue region. It is important to note that depending on their origin, these cells exhibit different behaviours, especially in regard to in vivo transplantation. Furthermore, the microenvironment in which these cells are found (niches) have an essential role in their behaviour as they control important aspects such as differentiation and self-renewal. This research project aimed for two distinct analyses. The first was to verify if there are mesenchymal stem cells derived from human dental socket curettage after dental extractions. The second, to analyse the stem cell niche in mouse dental pulp. In common, the two analyses were based on the use of markers previously used in the literature for the study of stem cells. As there are no specific and unique markers to identify these cells, an extensive combination of these markers among themselves, and laboratory techniques were performed. In the first study, after the isolation of the cells, special attention was given to their characterization by combining assays to evaluate stem.

cells properties and behaviours. In the second part of this study, we used the mouse dental pulp model for in vivo analysis of stem cell niches. In mice, the location of the niche responsible for the incisors continuous growth is known. In general our results showed that: 1) It is possible to isolate progenitor/stem cells from tissue curettage of the alveolus after tooth extractions. This fact is unprecedented and opens new perspectives for the obtention of stem cells for future clinical applications. 2) It is possible to observe the cells population diversity of the mouse dental pulp niche and through a hierarchical organization, we proposed a model for this niche. This model will provide basis for further studies aimed at evaluating the behavior of cells that form the niche, when isolated from the others, and opens the possibility for the analysis of the niche structure in other dental and non-dental tissues.

Eficácia na remoção da necrose óssea térmica: realizada por implantes osseointegráveis com câmaras coletoras / Removal effectiveness of thermal osteonecrosis: performed by osseointegrated implants with collecting chambers

Durante a confecção do alvéolo, promove-se o aumento da temperatura da broca devido à fricção, aquecendo o tecido ósseo adjacente e seus componentes celulares, podendo provocar a Necrose Óssea Térmica. A necrose óssea térmica deteriora a porção orgânica do tecido ósseo (tanto matriz óssea como as células), bem como as células diferenciadas e indiferenciadas presentes na circulação sanguínea e medula óssea local. Alguns trabalhos demonstraram que o aquecimento ósseo acima de 47oC por 1 minuto provoca tal fenômeno. Atualmente existem variações na técnica de perfuração com objetivo de diminuir o grau de aquecimento e aumentar as taxas de sucesso dos tratamentos reabilitadores. Sabemos que nem todos os profissionais são cautelosos em utilizar materiais de qualidade e que mesmo os materiais com qualidade, após repetido uso, perdem a eficácia. Seria ideal que o implante osseointegrável gerenciasse a remoção destas áreas de necrose óssea térmica, independentemente da execução correta da técnica de perfuração e da qualidade das brocas. Com isso, garantiríamos que o tecido ósseo poderia se reparar ao redor dos implantes da melhor maneira possível. Neste trabalho avaliamos a eficácia de 3 modelos de implante com câmaras coletoras funcionais diferentes, em tecido ósseo de minipig. O implante com câmara coletora interna demonstrou-se 37,22% mais eficaz que o implante com câmaras externas e 3 arestas cortantes, quando os alvéolos eram confeccionados sem irrigação e com brocas desgastadas. O implante com câmaras coletoras externas e 4 arestas também demonstrou-se eficaz, porém manteve 83,75% das células viáveis enquanto que no grupo com câmaras internas este resultado foi de 91,39%.

The manufacture of the alveolus can increase the temperature of the drill due to friction heating the adjacent bone tissue and its cellular components, this phenomenon is known by thermal osteonecrosis. The thermal osteonecrosis deteriorates the organic portion of bone (bone matrix and cells), as well as undifferentiated and differentiated cells circulating in the blood and bone marrow. Some studies have demonstrated that bone heating above 47oC for 1 minute causes this phenomenon. Currently there are variations in drilling technique aiming to reduce the heating degree and increase the success rates of rehabilitation treatments. We know that not all professionals are cautious of using quality materials and even the materials with quality after repeated use, lose their effectiveness. Would be ideal that implants manages and removes these areas with thermal osteonecrosis, regardless of the technique of implementing the drilling and the quality of drills. With this, we ensure that bone tissue could possibly repair around implants in the best way. In this study we evaluated the efficacy of 3 implant models with different functional collecting chambers in minipigs bone tissue. The implant with internal collection chamber proved to be 37.22% more effective than the implant with external chambers and three sharp edges, when the alveolus were manufactured without irrigation and uncut drills. The implant with external collecting chambers and four sharp edges also showed an effective but 83.75% of the cells remained viable while in the group with internal chambers this result was 91.39%.

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies - USP (HRAC-USP) - part 3: Oral and Maxillofacial Surgery

This paper presents the treatment protocol of maxillofacial surgery in the rehabilitation process of cleft lip and palate patients adopted at HRAC-USP. Maxillofacial surgeons are responsible for the accomplishment of two main procedures, alveolar bone graft surgery and orthognathic surgery. The primary objective of alveolar bone graft is to provide bone tissue for the cleft site and then allow orthodontic movements for the establishment of an an adequate occlusion. When performed before the eruption of the maxillary permanent canine, it presents high rates of success. Orthognathic surgery aims at correcting maxillomandibular discrepancies, especially anteroposterior maxillary deficiencies, commonly observed in cleft lip and palate patients, for the achievement of a functional occlusion combined with a balanced face.

Tratamento de defeitos alveolares verticais pela técnica de distração osteogênica / Treatment of vertical alveolar defects by means of osteogenic distraction technique

Introdução: a reconstrução alveolar de defeitos ósseos verticais ainda constitui um desafio dentro da Implantodontia. Dentre as diversas técnicas empregadas para a correção de tais defeitos, está a distração osteogênica, a qual tem sido descrita como uma técnica empregada para ganho de tecido ósseo e tecidos moles, sobretudo em cirurgias para reconstrução de rebordos alveolares mandibulares e maxilares, com a finalidade de permitir a instalação de implantes osseointegrados bem posicionados e com maior previsibilidade de sucesso quando submetidos a cargas funcionais. Objetivo: o propósito desse estudo foi avaliar a efetividade do procedimento em dois pacientes tratados pela técnica de distração osteogênica alveolar Relato de caso: os casos clínicos foram avaliados quanto ao ganho ósseo através de exame clínico e radiográfico, pré e pós-distração. Resultados: em ambos os casos, constatou-se, ao final do tratamento, ganho ósseo suficiente para posterior reabilitação com implantes. Conclusão: o sucesso relatado na literatura e nos casos apresentados comprova a eficiência da técnica e sua viabilidade clínica.

Introduction: Alveolar reconstruction of vertical bone defects remains a daunting challenge in implant dentistry. Among the various techniques used to correct such defects is distraction osteogenesis (DO), which has been described as a technique used to gain bone and soft tissues, especially in surgeries for reconstruction of mandibular and maxillary alveolar ridges to allow the placement of dental implants in a favorable position and with greater success predictability when subjected to functional loads. Objective: The purpose of this studywas to evaluate the effectiveness of DO in two patients treated with the technique of alveolar distraction osteogenesis. Case report: The clinical cases were evaluated for bone gain through clinical and radiographic examination, pre- and post-distraction. Results: At the end of treatment, both cases had gained sufficient bone as to enable subsequent rehabilitation with implants. Conclusions: The success rate reported in the literature and in the cases presented here prove the efficiency of the technique and its clinical feasibility.

The behavior of demineralized bone matrix (DBM) in post-extraction sockets / El comportamiento de matriz ósea desmineralizada (DBM) en alvéolos post-extracción

Autogenous bone grafts are considered to be the gold standard in bone regeneration because of their osteogenic activity; however, due to limited availability of intraoral donor sites and the need to resolve the demands of patients requires an alternative to these. Two male patients were submitted to implant surgery in two stages with 6 months intervals between each of them: the first was exodontia and placement of DBM graft into the socket; the second stage was the drill with a 2 mm internal diameter trephine in center of the alveolar ridge previously grafted with DBM and subsequent implant placement. The samples were analyzed under histological techniques. A very mature bone was observed at 6 months after DBM graft placement in the sockets, showing it to be a good alternative as bone graft.

Los injertos de hueso autólogo son considerados el "gold standard" en regeneración ósea debido a sus propiedades osteogénicas; sin embargo, debido a la limitada cantidad de sitios intraorales y la necesidad de resolver las necesidades de los pacientes, es que se requiere una alternativa para el mismo. Dos pacientes masculinos fueron sometidos a una cirugía de implantes en dos etapas con 6 meses de intervalo entre cada una de ellas: la primera consistió en la exodoncia y el posicionamiento del injerto de DBM en el alvéolo; la segunda etapa consistió en el fresado con una trefina de dos milímetros de diámetro interno en el centro del reborde alveolar previamente injertado con DBM y luego se posicionó el implante. Las muestras fueron analizadas bajo técnicas histológicas. Un hueso muy maduro fue observado a los 6 meses de haber injertado el DBM en los alvéolos, demostrando que podría ser una buena alternativa como injerto óseo.

Early dental implant failure in patient associated with oral bisphosphonates.

Oral bisphosphonates are routinely prescribed to post menopausal women. These have shown to increase the risk of osteonecrosis. However, this action may be augmented by local factors. A case report is presented showing an early implant failure in a patient taking oral bisphosphonates. Two implants were placed in left maxillary incisor area. Central incisor was associated with a previous endodontic failure and extraction. Lateral incisor was avulsed 3 years back. After 4 weeks of an implant placement, necrotic bone was evident along with the failing implant in central incisor area. This case report emphasizes on the incidence and an increased risk of implant failure in patients taking oral bisphosphonates.