Considerations about the relation between occlusal trauma and periodontal: peri-implant disease / Considerações sobre a relação entre trauma oclusal e doença periodontal: peri-implantar

O trauma oclusal é uma injúria ao aparato de inserção como resultado de força oclusal excessiva, e sua interação com a doença periodontal/peri-implantar permanece um tema muito discutido na literatura. O objetivo neste artigo foi realizar uma revisão de literatura acerca da relação entre trauma oclusal e doença periodontal/peri-implantar, por meio de uma análise de estudos experimentais em humanos e animais, bem como de revisões sistemáticas que discutiram o papel do fator oclusal como etiológico ou agravante da doença periodontal/peri-implantar. Concluiu-se que apesar de não ser considerado fator etiológico para o desenvolvimento de periodontite e peri-implantite, o trauma oclusal pode agravar a perda óssea ao redor de dentes ou implantes. Além disso, a diversidade das metodologias nos estudos sobre o assunto pode contribuir para os resultados conflitantes disponíveis, destacando-se a importância da padronização e maior detalhamento dos critérios de pesquisa.

The occlusal trauma is an injury to the insertion apparatus as a result of excessive occlusal force, and its interaction with periodontal/peri-implant disease remains controversial topic in the literature. The aim of this study was to review the literature about the relationship between occlusal trauma and periodontal/peri-implant disease, through an analysis of experimental studies in humans and animals, as well as systematic reviews that discussed the role of occlusal factor as etiological or aggravating periodontal/periplant disease. It was concluded that, although not considered a cause for the development of periodontitis and periimplantitis, occlusal trauma may exacerbate bone loss around the teeth or implants. Moreover, the diversity of methodologies in studies on the subject might contribute to the conflicting results available, highlighting the importance of standardization and more detailed research criteria.

The effect of piezosurgery with cvd tip in osteotomy in rat parietal bone: histologic and histomorphometric analysis / O efeito da piezocirurgia com ponta cvd em osteotomia no osso parietal de ratos: estudo histológico e histomorfométrico

O objetivo deste trabalho foi avaliar histológica e histomorfometricamente o efeito da piezocirurgia com ponta CVD em osteotomia realizada no osso parietal de ratos, comparativamente com a resposta do tecido ósseo frente ao protocolo padrão de osteotomia com brocas de tungstênio em baixa rotação. Material e Métodos: Defeitos foram feitos nos ossos parietais de 20 ratos Wistar machos, usando a ponta CVD e broca. Após 3, 7, 14 e 28 dias cinco animais foram sacrificados em cada período e o osso contendo os defeitos submetidos às análises histológica e histomorfométrica. Os resultados obtidos da histomorfometria foram submetidos à análise estatística RM ANOVA com nível de significância de α = 0,05. Os resultados obtidos foram submetidos ainda ao teste de comparação múltipla de Tukey. Resultados: A piezocirurgia promoveu corte preciso e mais lento com menos perda óssea, menor sangramento durante a cirurgia, favorecendo condições para uma reparação mais rápida em comparação com o método tradicional de osteotomia. Os resultados mostraram que nos períodos analisados diferença estatisticamente significativa entre os dois tipos de tratamento (p <0,05). Poucas células inflamatórias, formação óssea rápida, ferida cirúrgica limpa no grupo experimental em todos os períodos. Conclusão: A utilização da piezocirurgia com ponta CVD provou-se válida para a osteotomia, com cortes mais precisos, menos danos aos tecidos, resposta inflamatória menos pronunciada e formação óssea mais rápida nos primeiros períodos quando comparada com a broca de tungstênio em baixa velocidade...

The aim of this study was to compare the response of bone tissue in osteotomy under piezosurgery using a CVD tip in rat parietal bone in contrast with the standard protocol using lowspeed tungsten burs. Material and Methods: A bone defect model was created in parietal bone of 20 male Wistar rats using CVD tip and drill. Five animals were sacrificed after 3, 7, 14 and 28 days and bone containing the defects was submitted to the histologic and histomorphometric analysis. The results of histomorphometry were statistically analyzed using RM ANOVA with a significance level of α = 0.05. The results were still subjected to Tukey’s multiple comparison test. Results: The results showed statistically significant difference (p < 0.05) between the two types of treatment in the analyzed periods. Piezosurgery promoted slower and more precise cut with less bone loss and less bleeding during surgery, promoting conditions for a faster repair compared to the traditional method of osteotomy, fewer inflammatory cells, faster bone formation and cleaner surgical wound in the experimental group in all periods. Conclusion: The use of CVD tip in piezosurgery was proven to be valid for osteotomy, with more precise cuts, less tissue damage, less fewer pronounced inflammatory response and faster bone formation in the early healing periods when compared with low-speed tungsten burs...

Orthodontic extrusion and implant site development: two case reports / Extrusão ortodôntica pré-implante: relato de dois casos clínicos

The aim of this study was to report two cases of orthodontic extrusion performed prior to dental implant placement. The first one reports the case of a 57 year-old-female who presented internal root resorption in the left central incisor, and orthodontic extrusion of this element was indicated. The treatment lasted 24 weeks. At the end of this period, the dental implant was placed. The second clinical event refers to a patient of 66 years of age who had vertical fracture in the left central incisor. In this case, the orthodontic extrusion was conducted in 12 weeks. At the end of this period, the dental implant was placed and also the temporary crown, but without occlusal contact. Both cases reported consisted of the involvement of the left central incisor in the aesthetic area and low bone density. The cases reported demonstrated that orthodontic extrusion is a viable alternative to the aesthetic and functional reconstruction with prosthesis over dental implants...

A extrusão ortodôntica é um procedimento clínico utilizado no decorrer dos anos com a finalidade, dentre outras, de preservação e ganho de tecido ósseo para permitir a restauração estética e funcional. Assim, este trabalho teve por objetivo relatar dois casos de extrusão ortodôntica realizada previamente à colocação do implante dentário. O primeiro deles relata o caso de uma paciente de 57 anos de idade que apresentou reabsorção interna no incisivo central esquerdo sendo indicada a sua extrusão ortodôntica. O tratamento durou 24 semanas. Ao final deste período foi colocado o implante no local. O segundo caso clínico refere-se a um paciente de 66 anos de idade que apresentou fratura vertical no incisivo central esquerdo. Optou-se por realizar extrusão ortodôntica, por um período de 12 semanas. Finalizado este período, foi realizada a colocação de implante e provisório sem contato oclusal. Observou-se nestes relatos que ambos os casos apresentados consistiram no comprometimento do incisivo central esquerdo, em área estética e de pouca densidade óssea. Esses dois casos demonstraram a extrusão ortodôntica como uma alternativa viável para a reconstrução estética e funcional com prótese sobre implante...

Histomorphometric, radiographic and biomechanical analyses of platelet rich plasma associated with autogenous bone graft / Efeito do plasma rico em plaquetas associado ao enxerto autógeno na tíbia de coelhos: estudo histomorfométrico,radiográfico e biomecânico

Objective: The aim of this study was to evaluate the effectiveness of platelet rich plasma with and without autogenous bone graft in the bone repair of surgical defects in rabbit tibias. Material and Methods: In this research, 25 adult male rabbits were used. Two defects have been performed in each tibia, divided into four groups: control (C = defect naturally left to heal by clot formation), autogenous (A = bone defect + autogenous graft), PRP (PRP = bone defect + PRP) and autogenous + PRP (PRPA = bone defect + autogenous graft + PRP). All the defects were covered with a dPTFE membrane. Five other animals were sacrificed at 15, 30, and 60-day postoperatively. The pieces containing the defects were processed for histological and histomorphometric analysis. Other five animals were sacrificed after 30 and 60 days and submitted to biomechanical analysis, and all the specimens were sent to the radiographic evaluation of optical density. Results: The biomechanical, radiographic, and histomorphometric results showed larger resistance, optical density, and improving bone formation in the groups A and PRPA when compared with the groups C and PRP. Conclusion: This study showed there was not an improvement in the radiographic, mechanical, and bone formation parameters when PRP was used individually or associated to the autogenous bone graft...

Objetivo: O propósito deste trabalho foi avaliar o efeito do plasma rico em plaquetas associados ou não ao enxerto ósseo autógeno no processo de reparação óssea em defeitos cirúrgicos confeccionados na tíbia de coelhos. Material e Métodos: Nesta pesquisa foram utilizados 25 coelhos adultos, nos quais foram realizados 2 defeitos em cada tíbia, divididos nos seguintes grupos de acordo com o tratamento: controle (C - defeito preenchido somente por coágulo sangüíneo), autógeno (A - defeito + enxerto), PRP (PRP = defeito + PRP) e autógeno + PRP (PRPA - defeito + enxerto + PRP). Todos os defeitos foram recobertos com uma barreira de PTFE e decorridos 15, 30 e 60 dias, 5 animais foram sacrificados por período, sendo as peças contendo os defeitos processadas para análises histológica e histomorfométrica. Outros 5 animais foram sacrificados aos 30 e 60 dias e submetidos à análise das propriedades biomecânicas e todos os espécimes foram submetidos ao exame radiográfico para análise da densidade óptica. Resutados: Os resultados biomecânicos, radiográficos e histomorfométricos mostraram maior resistência, densidade óptica e maior formação óssea nos grupos A e PRPA quando comparados com os grupos C e PRP. Conclusão: Os resultados obtidos possibilitaram concluir que não houve uma melhora nos parâmetros radiográficos, mecânicos e na neoformação óssea quando o PRP foi usado isoladamente ou associado ao enxerto ósseo autógeno...

Fresh-frozen human bone allograft in vertical ridge augmentation: clinical and tomographic evaluation of bone formation and resorption.

The aim of the current study is to evaluate fresh-frozen human bone allografts (FHBAs) used in vertical ridge augmentation clinically and by computed tomography, and to analyze the resulting bone formation and graft resorption. Sixteen FHBAs were grafted in the maxillae and mandibles of 9 patients. The FHBAs, which were provided by the Musculoskeletal Tissue Bank of Marilia Hospital (Unioss), were frozen at -80°C. After 7 months, dental implants were placed and bone parameters were evaluated. Vertical bone formation was measured by computerized tomography before (T0) and at 7 months (T1) after the surgical procedure. Bone graft resorption was measured clinically from a landmark screw head using a periodontal probe. The results were analyzed by Student's t-test. Significant differences existed in the bone formation values at T0 and T1, with an average change of 4.03 ± 1.69 mm. Bone graft resorption values were 1.0 ± 0.82 mm (20%). Implants were placed with varying insertion torque values (35-45 Ncm), and achieved primary stability. This study demonstrates that FHBAs promote satisfactory vertical bone formation with a low resorption rates, good density, and primary implant stability.

Biocompatibility of a chlorhexidine local delivery systemin a subcutaneous mouse model

Objective: This study aimed evaluating histologically and histomorphometrically the response of the conjunctivetissue face to the implant of chlorhexidine chips in the subcutaneous tissues of rats. Study Design: In this research35 male rats Wistar were used to analyze the biocompatibility and the degradation process of chlorhexidine chip.In each animal, it was made 2 incisions for subcutaneous implantation of chlorhexidine chip (test group) and apolytetrafluorethylene membrane (control group). The morphological changes in subcutaneous implantations wereassessed after 1, 3, 5, 7, 10, 14, 21 days. The data were submitted to Friedman nonparametric test to analyze thecomparisons among observation periods and to allow the comparison among groups. Results: Differences werefound in the analysis of the inflammatory response when comparing the tested materials (p values ≤ 0.05). In testgroup was observed hemorrhage, edema and intense inflammatory infiltrate predominantly neutrophilic aroundmaterial. From 3-day and subsequent periods was verified granulation tissue externally at this infiltrate. From10-day on was observed crescent area of degradation of chlorhexidine chip, associated with neutrophilic and macrophagicinfiltrate, that maintained until 21-day. In the control group, moderate inflammatory infiltrate was observedinitially, predominantly polymorphonuclear, edema and granulation tissue 3-day period. The inflammatoryinfiltrate was gradually replaced for granulation tissue, culminating in a fibrous capsule. Giant multinucleate cellssituated at contact interface with the coating was examined since 3-day and persisted until 21-day. Conclusion:The chlorhexidine chip induces an intense acute inflammatory response at subcutaneous tissue of rats. Therefore,at conditions of this study was not biocompatible (AU)

Biocompatibility of a chlorhexidine local delivery system in a subcutaneous mouse model.

OBJECTIVE: This study aimed evaluating histologically and histomorphometrically the response of the conjunctive tissue face to the implant of chlorhexidine chips in the subcutaneous tissues of rats. STUDY DESIGN: In this research 35 male rats Wistar were used to analyze the biocompatibility and the degradation process of chlorhexidine chip. In each animal, it was made 2 incisions for subcutaneous implantation of chlorhexidine chip (test group) and a polytetrafluorethylene membrane (control group). The morphological changes in subcutaneous implantations were assessed after 1, 3, 5, 7, 10, 14, 21 days. The data were submitted to Friedman nonparametric test to analyze the comparisons among observation periods and to allow the comparison among groups. RESULTS: Differences were found in the analysis of the inflammatory response when comparing the tested materials (p values ≤ 0.05). In test group was observed hemorrhage, edema and intense inflammatory infiltrate predominantly neutrophilic around material. From 3-day and subsequent periods was verified granulation tissue externally at this infiltrate. From 10-day on was observed crescent area of degradation of chlorhexidine chip, associated with neutrophilic and macrophagic infiltrate, that maintained until 21-day. In the control group, moderate inflammatory infiltrate was observed initially, predominantly polymorphonuclear, edema and granulation tissue 3-day period. The inflammatory infiltrate was gradually replaced for granulation tissue, culminating in a fibrous capsule. Giant multinucleate cells situated at contact interface with the coating was examined since 3-day and persisted until 21-day. CONCLUSION: The chlorhexidine chip induces an intense acute inflammatory response at subcutaneous tissue of rats. Therefore, at conditions of this study was not biocompatible.

Polyurethane and PTFE membranes for guided bone regeneration: Histopathological and ultrastructural evaluation

AbstractObjective: The purpose of this study was to research a membrane material for use in guided bone regeneration.Study design: In this study, 25 male Wistar rats were used to analyze the biocompatibility and degradation processof biomembranes. The morphological changes in subcutaneous implantations were assessed after 7, 14, 21, 28 and70 days. The materials were made of polyurethane polymer (AUG) obtained from vegetal oil (Ricinus communis)and polytetrafluoroethylene membrane (PTFE). The surface characteristics of the physical barriers in scanningelectronic microscopic (SEM) were also evaluated. Results: In both groups, the initial histological analysis showedmoderate inflammatory infiltrate, which was predominantly polymorphonuclear. There was also a presence ofedema, which was gradually replaced by granulation tissue, culminating in a fibrous capsule. In the AUG group,some multinucleated giant cells were present in the contact interface, with the space previously occupied by thematerial. However, membrane degradation was not observed during the period studied. According to the presentSEM findings, porosity was not detected in the AUG or PTFE membranes. Conclusion: The researched material isbiocompatible and the degradation process is extremely slow or may not even occur at all (AU)

Polyurethane and PTFE membranes for guided bone regeneration: histopathological and ultrastructural evaluation.

OBJECTIVE: The purpose of this study was to research a membrane material for use in guided bone regeneration. STUDY DESIGN: In this study, 25 male Wistar rats were used to analyze the biocompatibility and degradation process of biomembranes. The morphological changes in subcutaneous implantations were assessed after 7, 14, 21, 28 and 70 days. The materials were made of polyurethane polymer (AUG) obtained from vegetal oil (Ricinus communis) and polytetrafluoroethylene membrane (PTFE). The surface characteristics of the physical barriers in scanning electronic microscopic (SEM) were also evaluated. RESULTS: In both groups, the initial histological analysis showed moderate inflammatory infiltrate, which was predominantly polymorphonuclear. There was also a presence of edema, which was gradually replaced by granulation tissue, culminating in a fibrous capsule. In the AUG group, some multinucleated giant cells were present in the contact interface, with the space previously occupied by the material. However, membrane degradation was not observed during the period studied. According to the present SEM findings, porosity was not detected in the AUG or PTFE membranes. CONCLUSION: The researched material is biocompatible and the degradation process is extremely slow or may not even occur at all.

Implante imediato sem retalho utilizando faceta de dentes extraídos em prótese provisória e carga imediata não funcional para otimização estética / Immediate flapless implant surgery using facets from extracted teeth in provisional prosthesis and immediate non-functional loading for aesthetic optimization

A reabilitação com implantes endósseos é hoje uma técnica segura e previsível. Entretanto, o tempo de tratamento ainda é um fator limitante para a satisfação dos pacientes. A instalação de implantes imediatamente após extração dental tem sido utilizada e apresenta muitas vantagens, principalmente com relação à estética e menor perda óssea marginal. O objetivo deste trabalho foi apresentar dois casos clínicos de instalação de implantes em alvéolos, sem retalho, utilizando a faceta vestibular dos dentes extraídos na confecção de provisórios e ativação imediata não funcional para a otimização da estética. Os resultados demonstraram a manutenção dos tecidos peri-implantares, presença de papila interproximal, ausência de inflamação, perda óssea insignificante e boa estética após 12 meses de avaliação. Os autores concluíram que a cirurgia sem retalho de implantes colocados em alvéolos usando facetas de dentes extraídos é uma abordagem aceitável em próteses sobreimplantes quando se consideram as condições que influenciam a estética. Unitermos - Unitermos - Implantes dentários; Carga imediata; Osseointegração.

The rehabilitation using endosseous implants is considered a safe and predictable technique; however, duration of treatment still is a concern for patients. The immediate implant in fresh dental sockets has been used in several studies and presents several advantages, such as soft tissue aesthetics, and smaller marginal bone loss. The aim of this study was to present two cases of flapless implants immediately placed in sockets using the buccal facets of extracted teeth as provisional restorations and non immediate functional loading for esthetic optimization. The results showed preservation of perimplant soft and hard tissues, presence of interproximal papilla, lack of inflammation, negligible bone loss and good aesthetics after 12 months. The authors concluded that flapless implant surgery with immediate placement in sockets using facets from extracted teeth is an acceptable approach in implant-supported prosthesis when conditions influencing aesthetics are considered.

Vertical bone augmentation using a polytetrafluoroethylene nonporous barrier for osseointegrated implants partially inserted in tibiae of rabbits.

PURPOSE: The aim of this study was to evaluate the possibility of obtaining guided bone regeneration using a polytetrafluoroethylene (PTFE) nonporous barrier for 2 endosseous implants, partially inserted in tibiae of rabbits. MATERIALS AND METHODS: Histologic characteristics of the interface between titanium implants (one group with titanium plasma-coated implants and the other group with acid-treated surfaces) and of the regenerated bone were also studied. Twenty screw-vent implants were placed in tibiae of 5 male New Zealand rabbits, 2 at the right side and 2 at the left side, protruding 3 mm from the bone level, to create a horizontal bone defect. At the experimental group the implants were protected with a PTFE nonporous barrier, whereas no barriers were used in contralateral implants. Animals were sacrificed 3 months after surgery and biopsy specimens were evaluated histologically and histomorphometrically under light microscopy. Student's t test was used for statistical analysis. RESULTS: The histologic measurements showed a mean gain in bone height of 2.15 and 2.42 mm for the barrier group and 1.95 and 0.43 mm for the control group, for the titanium plasma-spray and acid-treated implant surfaces, respectively. CONCLUSION: The results of the investigation revealed that the placement of implants protruding 3 mm from crestal bone defects may result in vertical bone augmentation using a nonporous PTFE barrier.

Fresh-frozen human bone graft for repair of defect after adenomatoid odontogenic tumour removal.

The aim of this paper was report the clinical, radiographic, and histological case of adenomatoid odontogenic tumour (AOT) in adolescent woman as well as present the reconstructive treatment of AOT using fresh-frozen human bone graft with guided bone regeneration. AOT is a benign, noninvasive lesion with slow but progressive growth. Biopsy and microscopic examination confirmed the presence of an AOT. Treatment was conservative and the prognosis was excellent. The patient has been followed-up for without recurrence. The use of fresh-frozen human bone graft can be a safe choice for reconstruction of the bone defects to treat AOT.

Trauma oclusal x tecidos periodontais: ação da osteopontina e do receptor ativador do fator nuclear kappa B / Occlusal trauma x periodontal tissue: action of the osteopontin and receptor activator of nuclear factor Kappa B ligand

O trauma oclusal é causado pela força oclusal excessiva e muitas vezes está associado com a perda do osso alveolar. Na presença de trauma oclusal, periodontites provocadas por biofilme estão sujeitas a ter uma evolução mais rápida que periodontites onde o trauma oclusal não está associado. Nesta revisão foi detalhada a atuação de duas proteínas (osteopontina e RANKL) que podem estar envolvidas neste processo. Sabe-se que a osteopontina é uma proteína produzida sob carga mecânica e induz a migração dos osteoclastos para o local da reabsorção. O receptor ativador do fator nuclear Kappa B (RANKL) é um importante fator na diferenciação, ativação e sobrevivência dos osteoclastos, e participa da indução in vitro da osteopontina intracelular. Entretanto, o envolvimento do RANKL na reabsorção óssea inflamatória, com ou sem trauma oclusal, e o papel da osteopontina nas células ainda não está claro. No presente estudo, uma revisão de literatura foi realizada com o objetivo de elucidar a imunohistoquímica do trauma oclusal associado aos tecidos periodontais, enfatizando a atuação da osteopontina e do RANKL, assim como a relação entre o trauma oclusal e os tecidos periodontais. Com base no que existe atualmente na literatura, o mecanismo preciso de degradação periodontal sob excessiva carga oclusal ainda não está bem estabelecido em virtude da complexa ação das referidas proteínas.

The occlusal trauma is caused by excessive occlusal loading and many times are associated with the anatomy ofthe osseous structures. In the presence of occlusal loading, periodontitis caused for bacterial film could be an evolution faster than periodontitis disease where the occlusal trauma is not associated. In this review, it will be emphasized the action of two proteins (osteopontin and RANKL) that can be involved in this process. The osteopontin is known to be reduced upon mechanical loading and is considered to induce migration of osteoclasts to the resorption bone. The receptor activator of nuclear factor Kappa B (RANKL) is an important factor in the differentiation, activation and survival of the osteoclasts, and participates of the induction in vitro of the intracellular osteopontin. However, the evolvement of the RANKL in the inflammatory osseous resorption, with or without oclusal loading, and the function of the osteopontin in the cells is unclear. In the present study, a literature review was carried through with the objective to elucidate the immunohistochemistry of the occlusal trauma associate to the periodontal tissues, emphasizing the action of osteopontin and RANKL, as well as the relation between the occlusal loading and periodontal tissues. On the basis of what it exists currently in literature, the necessary mechanism of the fabric periodontal under excessive occlusal loading was unclear because of the complex action of these proteins.

Calcium sulfate and PTFE nonporous barrier for regeneration of experimental bone defects.

The aim of the study was to evaluate the possibility to obtain guided bone regeneration with two types of physical barriers (calcium sulfate and PTFE nonporous barrier) in surgical defects created in rat parietal bones. In the right parietal bone the calcium sulfate barrier filled out the whole defect and in the left parietal bone the barrier of PTFE was positioned in the floor and externally to the surgical defect. After 7, 14, 30 and 45 days four animals were sacrificed in each period and the bone containing the defects were submitted to the microscopic analysis. The results of the study revealed that the PTFE barrier was more effective for bone regeneration in shallow transcortical defects compared to the calcium sulfate. However, additional experiments are necessary to determine if calcium sulfate would be successful in other bone defects types or the use of the material under another consistence could complement the results obtained in this work.

Calcium sulfate and PTFE nonporous barrier for regeneration of experimental bone defects

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The aim of the study was to evaluate the possibility to obtain guided bone regeneration with two types of physical barriers (calcium sulfate and PTFE nonporous barrier) in surgical defects created in rat parietal bones. In the right parietal bone the calcium sulfate barrier filled out the whole defect and in the left parietal bone the barrier of PTFE was positioned in the floor and externally to the surgical defect. After 7, 14, 30 and 45 days four animals were sacrificedin each period and the bone containing the defects were submitted to the microscopic analysis. The results ofthe study revealed that the PTFE barrier was more effective for bone regeneration in shallow transcortical defects compared to the calcium sulfate. However, additional experiments are necessary to determine if calcium sulfate would be successful in other bone defects types or the use of the material under another consistence could complement the results obtained in this work

Enxerto ósseo em levantamento de seio maxilar com osso humano fresco congelado / Bone graft in maxillary sinus with fresh frozen allogeneic bone: a case report

A perda dental em maxila posterior promove a reabsorção do tecido ósseo, o que, juntamente com a pneumatização do seio maxilar gera dificuldades para a reabilitação com implantes osseointegrados. O procedimento de enxerto ósseo em seio maxilar tem sido descrito desde a década de 70 com bons resultados; no entanto, faz-se a necessidade de uma segunda área cirúrgica para obtenção de osso autógeno, o que provoca maior desconforto, aumento do tempo cirúrgico e maior grau de morbidade dos pacientes. Este trabalho tem como finalidade apresentar um caso clínico de utilização de osso humano fresco congelado proveniente de banco de tecidos em enxerto ósseo em seio maxilar. Após seis meses, o enxerto se apresentou integrado, denso e foram instalados três implantes no local. A avaliação histológica demonstrou sinais de osso maduro, remodelado e vital, o que demonstrou que pode ser uma alternativa ao osso autógeno.

Osso humano fresco congelado em reconstruções ósseas: estudo retrospectivo e relato de casos / Frozen human bone in the bone reconstruction: retrospective study and cases report

A utilização de enxertos ósseos previamente à instalação de implantes é, muitas vezes, necessária para uma reabilitação estética e funcional com prótese sobreimplante. A busca por materiais que substituam o osso autógeno tem sido motivo de muitas pesquisas. O propósito do presente trabalho é descrever os resultados retrospectivos iniciais de enxertos de osso humano frescocongelado realizados em 76 casos de pacientes do curso de Implantodontia da Faculdade de Odontologia de São José dos Campos – Unesp e de clínica particular. Dois casos clínicos foram utilizados para ilustrar que utilização deosso humano fresco congelado é uma alternativa viável para reconstrução dos rebordos atróficos e enxertos nos seios maxilares.

Carga imediata não funcional em implantes unitários em maxila posterior: relato de caso / Non functional immediate loading in single implants in posterior jaw: a case report

A utilização de implantes na reabilitação de pacientes desdentados tem apresentado bons resultados. O tempo de tratamento consiste em um fator de desconforto para os pacientes. Vários estudos têm demonstrado que a diminuiçãodo tempo de tratamento com ativação imediata dos implantes pode apresentar resultados satisfatórios, desde que alguns fatores sejam levados em consideração no planejamento. O presente estudo tem como objetivorelatar um caso clínico de implante unitário ativado imediatamente em região posterior de maxila. Concluímos que a carga imediata em implantes unitários pode ser considerada previsível desde que fatores sejam avaliadosdurante o planejamento.

Bone defect regeneration with bioactive glass implantation in rats

O objetivo deste estudo foi avaliar a resposta histológica após a implantação de dois tipos de cerâmicas bioativas em defeitos criados na tíbia de ratos. Dezesseis ratos da raça Wistar, pesando 300g, foram divididos em dois grupos: PerioGlass (PG) (n=8) e Biogran (BG) (n=8). Defeitos ósseos unicorticais de 3 mm de diâmetro foram realizados na tíbia dos animais e preenchidos com os dois tipos de partículas cerâmicas. Os animais foram sacrificados aos 7, 14, 30 e 60 dias no pós-operatório. O material preparado para processamento e exame histológico em microscopia óptica foi corado com hematoxilina-eosina e tricrômio de Mallory. Aos 7 dias ambos os grupos apresentaram septos ósseos neoformados, mais intensos no grupo PG. Isto também foi observado aos 14 dias. Nos períodos posteriores (30 e 60 dias), ambos os grupos apresentaram tecido ósseo mais maduro ao redor das partículas cerâmicas. As trabéculas ósseas formadas em todos os períodos experimentais foram justapostas com as partículas. Podemos concluir que ambos os materiais promoveram o preenchimento ósseo em toda a extensão do defeito independente de suas granulações comprovando suas propriedades osteocondutivas.

Bone defect regeneration with bioactive glass implantation in rats.

The main goal of this study was to histologically evaluate the healing of surgically created defects on the tibiae of adult male rats after implantation of two types of bioactive glass. Sixteen adult Wistar rats (body weight of 300g) were divided into two groups: PerioGlas (PG) (n=8) and BioGran (BG) (n=8). Unicortical bone defects with 3-mm diameter were performed in both tibiae of the animals and filled with two types of glass particles. The rats were then sacrificed at 7, 14, 30 and 60 days, and the tissues were prepared for histological processing, sectioning, and staining with hematoxylin and eosin, as well as Mallory trichrome, and analyzed under light microscope. Within 7-14 days, both groups presented connective tissue septa with new bone formation, more intense in the PG group. In the subsequent periods (30 and 60 days), both groups presented more mature bone tissue around the glass particles. Bone trabeculae formed in all experimental periods were juxtaposed to the glass particles. It can be concluded that both materials promoted comparable bone formation over the entire extension of the defect, independently of the size of the granules, thus confirming their biological osteoconductive property.