Regeneração óssea guiada para aumento horizontal de rebordo utilizando fibrina rica em plaquetas associada a enxertos ósseos: revisão de literatura / Guided bone regenerationfor horizontal bone augmentation using platelet- rich fibrin associated with bone grafts: literature review

Objetivo: revisar a literatura sobre os diferentes tipos de derivados de plaquetas autólogas e o desempenho clínico do uso do sticky bone para aumento ósseo horizontal de rebordo. Materiais e métodos: Para realização dessa revisão foram realizadas buscas nas bases de dados PubMed, Google Scholar e Web of Science, utilizando os seguintes descritores: "platelet-rich fibrin" AND "sticky bone" OR "alveolar bone grafting" AND "sticky bone" OR "guided bone regeneration" AND "sticky bone" AND "alveolar ridge augmentation" OR "Alveolar ridge augmentation" AND "sticky bone". Foram incluídos artigos publicados em inglês, que abordavam conceitos relacionados aos agregados plaquetários e a regeneração óssea guiada para aumento ósseo horizontal de rebordo utilizando fibrina rica em plaquetas associada à enxertos ósseos (sticky bone). Resultados: Após avaliação dos estudos encontrados foram selecionados 11 artigos sobre o uso do sticky bone para aumento horizontal de rebordo. Para compor este trabalho foram selecionados também 14 estudos de revisão e artigos associados ao tema. Por ser de fácil aplicação e obtenção, muitos autores têm estudado as aplicações cirúrgicas do sticky bone e os resultados demonstram que o aumento horizontal do rebordo utilizando essa técnica pode ser realizado de forma previsível. Conclusão: apesar de haver estudos promissores sobre o uso do sticky bone, falta evidência na literatura sobre seu sucesso clínico. Assim, para compreender o potencial regenerativo desta técnica são necessários um maior número de estudos randomizados, com diferentes materiais de enxerto e protocolos padronizados de obtenção do sticky bone.(AU)

Objective: to review the literature on the different types of autologous platelet derivatives and the clinical performance of using sticky bone for horizontal bone ridge augmentation. Materials and methods: In order to conduct this review, it was conducted searches in the PubMed, Google Scholar, and Web of Science databases using the following descriptors: "platelet-rich fibrin" AND "sticky bone" OR "alveolar bone grafting" AND "sticky bone" OR "guided bone regeneration" AND "sticky bone" AND "alveolar ridge augmentation" OR "Alveolar ridge augmentation" AND "sticky bone". It included articles published in English that addressed concepts related to platelet aggregates and guided bone regeneration for horizontal bone augmentation using platelet-rich fibrin associated with bone grafts (sticky bone). Results: After evaluating the studies found, were selected 11 articles on the use of sticky bone for horizontal ridge augmentation. To compose this work, 14 review studies and articles associated with the topic were also selected. Due to its ease of application and availability, many authors have explored the surgical applications of sticky bone, and the results indicate that horizontal ridge augmentation using this technique can be predictably performed. Conclusion: while there are promising studies on the use of sticky bone, the literature lacks evidence regarding its clinical success. Therefore, to fully understand the regenerative potential of this technique, further randomized studies are needed, involving different graft materials and standardized protocols for obtaining sticky bone.(AU)

In vitro evaluation of membranes for regenerative procedures against oral bacteria

Abstract The current literature on guided bone regeneration (GBR) and guided tissue regeneration (GTR) membrane contamination reports that the physicochemical characteristics of these biomaterials might influence affinity to bacteria, which appears to be a major drawback for the clinical outcome of the regenerative procedures. Thus, this study aimed to evaluate, in vitro, a multispecies biofilm adherence and passage of bacteria through different types of commercially available membranes for GTR/GBR. Four types of membranes were tested (n=12): LC) Lumina Coat®; JS) Jason®; BG) Biogide®; and LP) Lumina PTFE®. Aluminum foil (AL) simulated an impermeable barrier and was used as the control. The membranes were adapted to specific apparatus and challenged with a mixed bacterial culture composed of A. actinomycetemcomitans b, S. mutans, S. mitis, and A. israelii. After 2 h or 7 days, bacterial adhesion and passage of bacteria were evaluated through CFU counting, which was analyzed by two-way ANOVA e post hoc Tukey, at a 5% significance level. Representative areas of two membranes of each group were analyzed through scanning electron microscopy (SEM) to assess the morphology and organization of the biofilm over the membrane fibers. LC and LP presented similar values of adhered bacterial cells (p > 0.05), significantly inferior when compared to the other groups, in both time points (p < 0.05). All the tested groups were permeable to bacterial cells, with no significant difference between the trial period of 2 h and 7 days (p > 0.05). SEM analyses demonstrated that adhered bacteria number increased throughout the time points (2 h < 7 days). Commercially available biological membranes demonstrated intense bacterial adherence and passage of bacteria, which increased throughout the trial period.

Resumo O objetivo deste estudo foi avaliar, in vitro, a aderência do biofilme multiespécie e a passagem de bactérias através dos diferentes tipos de membranas disponíveis comercialmente para RTG/ROG. Quatro tipos de membranas foram testados (n=12): LC) Lumina Coat®; JS) Jason®; BG) Biogide®; e LP) Lumina PTFE®. Papel alumínio (AL) simulou uma barreira impermeável e foi usado como controle negativo. As membranas foram adaptadas à um aparato específico e desafiadas com uma cultura bacteriana mista composta de A. actinomycetemcomitans b, S. mutans, S. mitis, e A. israelii. Após 2 h ou 7 dias, a aderência e passagem bacteriana foi avaliada através da contagem de UFCs. Duas membranas de cada grupo foram analisadas através da microscopia eletrônica de varredura (MEV). LC e LP apresentaram valores semelhantes de células bacterianas aderidas (p < 0.05), significativamente inferiores quando comparados aos outros grupos, em ambos os períodos experimentais (p < 0.05). Desde a análise inicial, todos os grupos testados foram permeáveis às células bacterianas, sem diferença significativa entre o período experimental de 2 h e 7 dias (p > 0.05). As análises em MEV demonstraram que o número de bactérias aderidas aumentou com o tempo (2 h < 7 days). Membranas biológicas comercialmente disponíveis demonstraram intensa aderência bacteriana e passagem de bactérias, que aumentou durante os períodos experimentais.

Enucleação de cisto residual e regeneração óssea guiada com enxerto sintético a base de fosfato de cálcio bifásico e hidroxiopatita: relato de caso clínico / Enucleation of residual cyst and guided bone regeneration with synthetic graft based on biphasic calcium phosphate and hydroxyopathite: clinical case report / Enuclación de quistes residuales y regeneración ósea guiada con injerto de sintético a base de fosfato de calcio bifásico e hidroxiopato: reporte de caso clínico

Os cistos residuais são definidos como cistos inflamatórios, revestidos por epitélio e em seu interior apresentam um conteúdo semifluido ou fluido, que em sua dominância ocorrem na maxila. Em geral não apresentam sintomas e se não tratado corretamente pode ocasionar uma reabsorção óssea e enfraquecimento da maxila ou mandíbula. O principal objetivo deste trabalho é relatar o caso de uma paciente do sexo feminino, que compareceu a Clinica Odontológica relatando um cisto na região dos incisivos centrais superiores. No exame clinico, notou-se um aumento de volume na porção vestibular do processo alveolar, sendo sua consistência macia e sintomatologia dolorosa a palpação. Portanto, optou-se por sua enucleação cirúrgica da lesão, seguida de uma minuciosa descontaminação mecanica e quimica, seguida de regeneração óssea guiada utilizando um enxerto ósseo sintético a base de fosfato de cálcio e hidroxiapatia sendo seu diagnóstico confirmado através de exame histopatológico. Contudo neste relato pode-se observar que a enucleação do cisto residual seguida por uma boa descontaminação mecanica e quimica, associado a regeneração óssea guiada se mostrou eficaz no tratamento deste caso, não ocorrendo recidivas no periodo de acompanhamento. PALAVRAS-CHAVE: Cistos Residuais; Cistos Odontogênicos; Biópsia; Regeneração Óssea Guiada; Enxerto Ósseo.

Residual cysts are defined as inflammatory cysts, covered by epithelium and in their interior they have a semi-fluid or fluid content, which in their dominance occur in the maxilla. In general, they do not have symptoms and if not treated correctly, it can cause bone resorption and weakening of the maxilla or mandible. The main objective of this work is to report the case of a female patient, who attended the Dental Clinic reporting a cyst in the region of the upper central incisors. On clinical examination, an increase in volume was noted in the vestibular portion of the alveolar process, with a soft consistency and painful symptoms on palpation. Therefore, we opted for its surgical enucleation of the lesion, followed by a thorough mechanical and chemical decontamination, followed by guided bone regeneration using a synthetic bone graft based on calcium phosphate and hydroxyapathy, the diagnosis being confirmed through histopathological examination. However, in this report, it can be seen that the enucleation of the residual cyst followed by good mechanical and chemical decontamination, associated with guided bone regeneration, proved to be effective in the treatment of this case, with no recurrences occurring during the follow-up period.

Los quistes residuales se definen como quistes inflamatorios, recubiertos por epitelio y en su interior tienen un contenido semilíquido o líquido, que en su predominio se presentan en el maxilar. Por lo general, no presentan síntomas y si no se tratan correctamente, pueden causar reabsorción ósea y debilitamiento del maxilar o la mandíbula. El objetivo principal de este trabajo es reportar el caso de una paciente de sexo femenino, que acudió a la Clínica Odontológica por presentar un quiste en la región de los incisivos centrales superiores. Al examen clínico se aprecia aumento de volumen en la porción vestibular del proceso alveolar, de consistencia blanda y sintomatología dolorosa a la palpación. Por ello, se optó por su enucleación quirúrgica de la lesión, seguida de una exhaustiva descontaminación mecánica y química, seguida de regeneración ósea guiada mediante injerto óseo sintético a base de fosfato cálcico e hidroxiapatía, confirmándose el diagnóstico mediante examen histopatológico. Sin embargo, en este reporte se puede ver que la enucleación del quiste residual seguida de una buena descontaminación mecánica y química, asociada a la regeneración ósea guiada, demostró ser eficaz en el tratamiento de este caso, sin que se presentaran recurrencias durante el seguimiento período de subida.

Microcirugía endodóntica: regeneración ósea guiada en defecto óseo tunelizado: caso clínico / Endodontic microsurgery: guided bone regeneration in a through-and-through bone defect: a clinical case

Se presentó a la Cátedra de Endodoncia de la Facultad de Odontología de la Universidad de Buenos Aires un paciente masculino de 62 años de edad que al examen clínico presentaba una fístula vestibular en la zona de la pieza 1.2 y dolor a la percusión. Al examen radiográ-fico se identificó una lesión apical extensa abarcando las piezas dentarias 1.2 y 1.1 endodónticamente trata-das con alteración severa de la anatomía del espacio endodóntico, así como la presencia de postes metáli-cos que no respetaban el eje del canal radicular. Ante el análisis tomográfico se observó una perforación de la pieza 1.2 y una lesión periapical extensa afectando ambas corticales (vestibular y palatina). Se decidió un abordaje microquirúrgico con técnicas de regenera-ción ósea guiada (ROG) y se realizaron los controles clínico-tomográficos a los 6, 12 y 24 meses. Por otro lado, se evaluó con micromografía de rayos X la ana-tomía de los ápices radiculares resecados. La lesión extirpada fue analizada histológicamente (AU)

A 62-year-old male patient attended the Endodontics department of the Buenos Aires University. He was examined clinically and a vestibular fistula in 1.2 area and pain under percussion were found. Radiographic examination identified an extended periapical lesion compromising teeth 1.2 and 1.1 with endodontic treatment severely altering the root canal anatomy, as well as metallic cast posts that did not preserve root canal axis. Regarding the tomographic analysis, a vestibular root perforation was observed (1.2), and both, vestibular and palatal corticals, were affected. We decided to perform a surgical approach with guided bone regeneration techniques (GBR). Clinical-CBCT controls were done at 6, 12 and 24 months. Furthermore, the anatomy of the resected root apex-es was evaluated with X ray microtomography. The removed lesion was histologically analyzed (AU)

Progress of research on bone grafts for implant dentistry / 口腔医学

@#With the development of dental implant techniques, dental rehabilitation of partially or totally edentulous patients with oral implants has become a common practice. Adequate bone volume in the implant area is a key factor for the success of implant restoration. However, insufficient bone volume in the implant area is very common in clinical practice, which jeopardizes the structural, functional, and esthetic outcomes of implant treatment. Bone augmentation with bone grafts is one of the methods commonly used in clinical practice to meet the requirements of implantation. Properties of bone grafts, such as biocompatibility,osteoconduction, osteoinduction and osteogenesis, are important to the success of bone augmentation. This paper reviews current research on dental bone grafts about their clinically relevant capabilities, classification and their potential development in the future, in order to provide theoretical reference for clinical application of bone grafts and successful implant restoration.

Análise comparativa entre técnicas cirúrgicas de enxertia óssea em reabilitação de maxila atrófica: transplante celular odontológico (TCO) e técnica convencional de enxertia óssea ­ relato de caso clínico / Comparative analysis between surgical techniques of bone grafting in rehabilitation of atrophic maxilla: dental cell transplantation (OCT) and conventional bone grafting technique - a case report

A reabilitação de maxila atrófica se apresenta ainda nos dias de hoje como um desafio anatômico/fisiológico para os profissionais da área odontológica que visam buscar a instalação de implantes para futuras reabilitações protéticas, tendo em vista o grau de dificuldade de reconstituição do rebordo alveolar perdido. Com o intuito de reabilitar essas maxilas frente às adversidades, diferentes técnicas são propostas tais como enxertos ósseos autógenos, homógenos, substitutos ósseos alógenos, xenógenos e aloplásticos e suas respectivas técnicas. O objetivo deste trabalho foi apresentar um relato de caso clínico, no qual duas técnicas de reconstituição de rebordo alveolar de hemi-arco foram realizadas na mesma maxila utilizando biomaterial em bloco, visando comparar os resultados histológicos e clínicos. Após 5 meses da realização da enxertia, foi coletado material dos enxertos alveolares bilateralmente utilizando-se brocas trefinas para estudo histológico. Através da metodologia empregada, pode-se observar maior formação de estrutura óssea no lado em que foi praticada a metodologia transplantes celular odontológico (TCO), que preconiza a associação de sangue medular mandibular ao biomaterial, em relação a técnica contralateral em que utilizou a metodologia convencional, que preconiza a associação ao biomaterial do sangue periférico. Pode-se observar através da metodologia empregada que a utilização de biomateriais potencializados com sangue medular mandibular apresentou maior crescimento de estrutura óssea, incrementando em torno de 35% a mais na neoformação.de osso vital.

The rehabilitation of atrophic maxilla is still presented today as an anatomical/physiological challenge for professionals in the dental field who aim to seek the installation of implants for future prosthetic rehabilitations, in view of the degree of difficulty in reconstituting the lost alveolar ridge. In order to rehabilitate these jaws in the face of adversity, different techniques are proposed such as autogenous, homogenous bone grafts, allogeneic, xenogenous and alloplastic bone substitutes and their respective techniques. The aim of this study was to present a clinical case report, in which two hemi-arch alveolar ridge reconstruction techniques were performed in the same maxilla using biomaterial en bloc, in order to compare the histological and clinical results. After 5 months of grafting, material was collected from the alveolar grafts bilaterally using trephine burs for histological study. Through the used methodology, it was possible to see greater bone formation of structure on the side in which the dental cell transplantation (TCO) methodology was practiced, which advocates the association of mandibular medullary blood to the biomaterial, in relation to the contralateral technique in which the methodology was used conventional method, which advocates the association with peripheral blood biomaterial. It can be observed through the used methodology that the use of biomaterials potentiated with mandibular medullary blood showed greater growth of bone structure, increasing around 35% more in the neoformation of vital bone.

Application of plasmatrix in horizontal bone augmentation for implant placement / 口腔疾病防治

@#Tooth loss is accompanied by alveolar bone absorption or defect, resulting in insufficient bone and soft tissue. In addition to restoring the masticatory function of missing teeth, implant treatment should also needs to restore the contour and shape of the dental arch. Guided bone regeneration is a common means of bone increase. Xenogeneic granular bone substitute materials are widely used in the field of clinical bone augmentation due to their advantages of long degradation time and low immunogenicity, but other problems, such as inconvenient operation and low osteogenic activity, remain. Plasmatrix can effectively improve the effect of oral tissue regeneration and reduce the occurrence of postoperative complications, and its application in oral tissue regeneration is gradually increasing. This article first introduces the main application forms of plasmatrix in horizontal bone augmentation (mainly solid plasmatrix membrane and plasmatrix bone block), and reclassifies horizontal bone defects according to commonly used decision-making schemes in clinical bone augmentation, in other words, whether the implant can be placed in the ideal position and whether there is bone dehiscence after implantation. Type Ⅰ defects refers to the situation where the bone at the implant site can allow the insertion of an implant with ideal size, and there is no bone dehiscence around the implant, but the alveolar bone contour is not ideal; type Ⅱ defects refers to the situation that when an ideal size implant is placed at the implant site determined by the future prosthesis position, there will be bones on three sides of the implant, but there is bone dehiscence in the buccal bone wall (the length of bone dehiscence is less than 50% of the implant length); type Ⅲ defects refers to the situation where the bone volume at the implant site is not enough to for the placement of the ideal size implant at the ideal position, and bone grafting is required to restore the bone volume before the implant placement. The application of plasmatrix in different types of bone defects is then described. In type Ⅰ bone defects, the solid plasmatrix membrane is used instead of the collagen membrane; in type Ⅱ bone defects, the bone defect around the implant is filled by plasmatrix bone block and then covered with collagen membrane and solid plasmatrix membrane; and in type Ⅲ bone defects, plasmatrix bone block is used to replace autogenous bone block to fill the defect area, and titanium screws are used for fixation. The defect is then covered with a collagen membrane and a solid plasmatrix membrane. This article aims to provide oral clinicians with a comprehensive understanding of plasmatrix and simplify the guidelines for bone regeneration operations.

Aplication of digitally modified fence technique in vertical bone reconstruction / 口腔疾病防治

Objective@#To propose a digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate and explore its effect on vertical bone regeneration.@*Methods@#A total of 8 patients with severe vertical bone defects in the edentulous area who wanted to be treated with implants were included in this study. A digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate (fence technique) was used for bone augmentation. The patient's jaw, dentition, and soft tissue data were obtained for prosthetically guided implantation and bone regeneration. After virtual bone augmentation, a model of the jaw was obtained through 3D printing technology, and the titanium plate was bent accordingly. The virtual design was transformed through the template (including the base template and the attachment of a periosteal screw and bone block), so the actual osteogenesis space consistent with the design could be realized in the operation. Guided bone regeneration was performed according to the improved procedure and technical process. After 6 ~ 8 months of bone augmentation, cone beam CT was taken to evaluate the effect of bone augmentation. The implant was implanted according to the initial implant design, and bone tissue was obtained for HE and Masson staining. @* Results@#After 6 ~ 8 months of bone augmentation, the vertical linear bone increment reached (5.44 ± 1.73) mm. The implant was implanted according to the initial implant design, and the bone tissue was obtained for histological examination to show the formation of new bone.@*Conclusion@#Digital improved fence technique can simplify the preoperative and surgical procedures, and obtain good vertical bone augmentation results. In short, it is a kind of vertical bone augmentation technique worth popularizing and applying.

Application of plasmatrix in vertical bone augmentation for implant placement / 口腔疾病防治

@#Vertical bone augmentation surgery still faces considerable challenges in clinical practice due to various problems, such as difficulty in restoring the ideal alveolar bone height and biological complications, and because it is highly technically sensitive. Plasmatrix is derived from patients’ own blood, and it can effectively promote the vascularization of the regenerated area, recruit stem cells, and reduce inflammation when used in vertical bone augmentation. Based on studies published worldwide, this article first divides vertical bone augmentation into 3 categories according to the height of the expected alveolar ridge, namely, type Ⅰ, the required vertical bone gain is less than 4 mm; type Ⅱ, the required vertical bone gain is between 4-8 mm; and type Ⅲ, the required vertical bone gain is greater than 8 mm. In the type Ⅰ vertical bone augmentation, the plasmatrix bone block is directly placed in the defect area and covered with the plasmatrix membrane before tension-free suturing; in the type Ⅱ vertical bone augmentation, the plasmatrix bone block should be placed in the defect area and fixed with titanium nails and then covered with an absorbable collagen membrane and plasmatrix membrane with a tension-free suture; in the type Ⅲ vertical bone augmentation, additional active ingredients (such as bone morphogenetic protein, autologous bone, etc.) should be added to the plasmatrix bone block and strong fixation (such as titanium nails) should be used. Absorbable collagen and plasmatrix membranes should be used to cover the surface of the bone block, and the flap should be sutured. According to different types of vertical bone augmentation categories, the above methods optimize the vertical bone augmentation effect. This article aims to provide a reference and guidelines for oral clinicians to fully understand plasmatrix and simplify the classification and operation of vertical bone augmentation.

Clinical outcomes of immediate implantation and provisionalization combined with guided bone regeneration for a single anterior maxillary tooth with a thin facial bone phenotype / 口腔疾病防治

Objective@#To study the postoperative soft and hard tissue changes and aesthetic effect of immediate implantation and provisionalization (IIPP) combined with guided bone regeneration (GBR) for a single anterior maxillary tooth with a thin facial bone phenotype.@*Methods @# A total of 34 patients with thin facial bone (<1 mm) were categorized into two groups: a flapped GBR group and a flapless group. Tooth extraction and IIPP were conducted at the sites in both groups. Implant survival rates, dimensional changes in soft and hard tissues during the six- and twelve-month follow-ups, the pink esthetic score (PES) and patient satisfaction scores at the twelve-month follow-up were measured.@*Results @#The implant survival rates were 100% in both groups, and no complications occurred during the 12 months after surgery. The facial bone thickness remained over 2 mm on all measured sides, and the height of the facial bone crest remained at 1.39 mm at the 12-month follow-up in the flapped GBR group, while the facial bone thickness remained less than 2 mm on all measured sides, and the height of the facial bone crest remained at 1.03 mm at the 12-month follow-up in the flapless group. The absorption of facial bone at all measured sides in the flapped GBR group was greater than that in the flapless group (P<0.05). There was no significant difference between the two groups in the dimensional changes of labial soft tissues during the six- and twelve-month follow-ups (P>0.05). The mean PES scores were 10.29 ± 2.34 for the flap GBR group and 10.12±1.78 for the flapless group (P = 0.807). The mean patient satisfaction scores were 8.65 ± 1.27 in the flapped GBR group and 8.76 ± 1.25 in the flapless group, and the patients in both of the groups were satisfied with the esthetic outcomes (P = 0.787). @*Conclusion @#IIPP combined with GBR might be a prospective treatment strategy for a single anterior maxillary tooth with a thin facial bone phenotype, but the esthetic risks should never be ignored.

A prospective cohort study of immediate implantation and delayed implantation for a labial bony dehiscence defect in the maxillary aesthetic area / 口腔疾病防治

Objective @# To investigate the effect of immediate and delayed implant placement on dimensional changes in hard and soft tissues as well as esthetic outcomes. @*Methods @# A total of 40 maxillary single anterior teeth with a dehiscence defect on the labial bone (≤4 mm) were categorized into two groups according to the timing of implant placement: immediate implant placement (n = 20) or delayed implant placement (n = 20). Guided bone regeneration (GBR) was conducted at the sites using a flap approach, and the implants were given immediate provisionalization. Implant survival rates, dimensional changes in hard and soft tissues during the six- and twelve-month follow-ups, and pink esthetic scores (PESs) were measured. @*Results @# The implant survival rates in both groups were 100%, and no complications occurred during the follow-up time. There was no significant difference between the two groups at the measurement sites in the dimensional change of hard and soft tissues during the six- and twelve-month follow-ups. The largest resorption was observed at the implant neck, with a loss of (1.29 ± 0.71) mm in the immediate implant placement group and (1.43 ± 0.19) mm in the delayed implant placement group. The mean PES scores were (10.95 ± 1.51) for the immediate implant placement group and (11.05 ± 1.23) for the delayed implant placement group. @*Conclusion@# Immediate implantation or delayed implantation combined with GBR and immediate provisionalization might both be a prospective treatment strategy for a maxillary single anterior tooth with a dehiscence defect on the labial bone.

Clinical and histological evaluations of the effects of concentrated growth factor combined with deproteinated bovine bone mineral in site preservation / 口腔疾病防治

Objective@#To evaluate the osteogenic effect of concentrated growth factor (CGF) combined with deproteinated bovine bone mineral (DBBM) in site preservation using clinical and histomorphometric observations.@*Methods @#A total of 26 patients who needed extraction of affected teeth and received staged implantation after site preservation were selected. The patients were randomly divided into the DBBM group (Bio-Oss was implanted simultaneously after extraction) and CGF+DBBM group (CGF+Bio-Oss was implanted simultaneously after extraction), with 13 patients in each group, and both groups were covered with Bio-Gide collagen membrane. Cone beam computed tomography (CBCT) was performed preoperatively and 6 months later to measure the changes in alveolar bone height and width, and the bone specimens were drilled 6 months after site preservation during implant surgery for histological analyses.@*Results@# CBCT showed that the height and width of alveolar bone were absorbed 6 months after site preservation in the CGF+DBBM and DBBM groups, and the reduction in alveolar ridge width in the CGF+DBBM group was statistically less than the DBBM group (P <0.05). The histomorphometry results showed that the percentage of new bone in the CGF+DBBM and DBBM groups were 35.30% ± 3.56% and 26.38% ± 5.04%, respectively, and the amount of new bone in the CGF+DBBM group was statistically higher than the DBBM group (P<0.05). @*Conclusion @#CGF combined with DBBM is superior to DBBM in maintaining the alveolar bone volume and shape in site preservation, which creates favorable conditions for implant restoration.

Biocompatibility and effect on bone formation of a native acellular porcine pericardium: Results of in vitro and in vivo / 北京大学学报(医学版)

OBJECTIVE@#To examine the morphology and biocompatibility of a native acellular porcine pericardium (APP) in vitro and to evaluate its barrier function and effects on osteogenesis when used in guided bone regeneration (GBR) in vivo.@*METHODS@#First, the morphology of APP (BonanGenⓇ) was detected using a scanning electron microscope (SEM). Next, for biocompatibility test, proliferation of human bone marrow mesenchymal stem cells (hBMSCs) were determined using cell counting kit-8 (CCK-8) after being seeded 1, 3 and 7 days. Meanwhile, the cells stained with phalloidine and 4, 6-diamidino-2-phenylindole (DAPI) were observed using a confocal laser scanning microscopy (CLSM) to view the morphology of cell adhesion and pattern of cell proliferation on day 5. A 3-Beagle dog model with 18 teeth extraction sockets was used for the further research in vivo. These sites were randomly treated by 3 patterns below: filled with Bio-OssⓇand coverd by APP membrane (APP group), filled with Bio-OssⓇand covered by Bio-GideⓇmembrane (BG group) and natural healing (blank group). Micro-CT and hematoxylin-eosin (HE) were performed after 4 and 12 weeks.@*RESULTS@#A bilayer and three-dimensional porous ultrastructure was identified for APP through SEM. In vitro, APP facilitated proliferation and adhesion of hBMSCs, especially after 7 days (P < 0.05). In vivo, for the analysis of the whole socket healing, no distinct difference of new bone ratio was found between all the three groups after 4 weeks (P>0.05), however significantly more new bone regeneration was detected in APP group and BG group in comparison to blank group after 12 weeks (P < 0.05). The radio of bone formation below the membrane was significantly higher in APP group and BG group than blank group after 4 and 12 weeks (P < 0.05), however, the difference between APP group and BG group was merely significant in 12 weeks (P < 0.05). Besides, less resorption of buccal crest after 4 weeks and 12 weeks was observed in APP group of a significant difference compared in blank group (P < 0.05). The resorption in BG group was slightly lower than blank group (P>0.05).@*CONCLUSION@#APP showed considerable biocompatibility and three-dimentional structure. Performing well as a barrier membrane in the dog alveolar ridge preservation model, APP significantly promoted bone regeneration below it and reduced buccal crest resorption. On the basis of this study, APP is a potential osteoconductive and osteoinductive biomaterial.

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.

Guided bone regeneration-assisted orthodontic treatment for closing the space of missing central incisors / 华西口腔医学杂志

Long-term missing teeth can lead to alveolar bone loss in the edentulous area. Guided bone regeneration (GBR) is a bone augmentation method. It is widely used in clinical practice and broadens the indications of orthodontic treatment to a certain extent. This article reports a case of an adult patient with edentulous space in the maxillary central incisor, which was successfully closed through orthodontic treatment combined with GBR. This study will provide a re-ference for future clinical work.

Avaliação do uso de membrana de polipropileno na preservação do volume alveolar após exodontias: estudo clínico randomizado prospectivo / Evaluation of the use of polypropylene membrane to preserve alveolar volume after extraction: a prospective randomized clinical study

O objetivo deste estudo foi mensurar as alterações lineares no alvéolo, por meio de imagens de tomografia computadorizada cone beam, imediatamente após exodontia e após 120 dias usando ou não a membrana de polipropileno. A população deste estudo consistiu de 19 pacientes da Faculdade de Odontologia de Araçatuba ­ UNESP, com dentes com indicação de extração anteriores ou posteriores. Foi confeccionado um guia tomográfico de acrílico, que apresentava três pontos de gutta percha, localizados no centro da região do alvéolo, a fim de localização dos cortes tomográficos. Os 30 alvéolos foram divididos em dois grupos: grupo controle (C), em que foi feita a extração dentária e sutura e grupo membrana (B), em que foi feita a extração dentária, instalação da membrana e sutura. As tomografias foram analisadas em três tempos: pré-operatório, pósimediato (T1) e após 120 dias (T2), por meio da visualização dos cortes coronais na região dos alvéolos. A reabsorção após exodontia foi avaliada no sentido vertical e horizontal. A média da reabsorção vertical após 120 dias de pós operatório foi de 0,652 mm no grupo C e de 0,5145 mm no grupo M. A média da reabsorção horizontal foi de 0,76 mm no grupo C e de 0,45 mm no grupo M, foi aplicado o teste estatístico T de Student, o qual mostrou haver diferença estatisticamente significante p=0,021. O uso da membrana de polipropileno sobre os alvéolos, imediatamente após a exodontia contribui positivamente para a manutenção da reabsorção do rebordo alveolar(AU)

The aim of this study was to measure the linear changes in the alveolus, using cone beam computed tomography images, immediately after extraction and after 120 days using or not the polypropylene membrane. The population of this study consisted of 19 patients from the Faculty of Dentistry of Araçatuba - UNESP, with teeth with indication of anterior or posterior extraction. An acrylic tomographic guide was made, which had three points of gutta percha, located in the center of the alveolus region, in order to locate the tomographic sections. The 30 alveoli were divided into two groups: control group (C), in which tooth and suture extraction was performed and membrane group (B), in which tooth extraction, membrane installation and suture were performed. The CT scans were analyzed in three stages: preoperative, post-immediate (T1) and after 120 days (T2), through the visualization of the coronal sections in the region of the alveoli. Resorption after extraction was evaluated in the vertical and horizontal directions. The average of vertical resorption after 120 days after surgery was 0.652 mm in group C and 0.5145 mm in group M. The average of horizontal resorption was 0.76 mm in group C and 0.45 mm in group M, Student's T test was applied, which showed a statistically significant difference p = 0.021. The use of the polypropylene membrane over the alveoli, immediately after extraction, contributes positively to the maintenance of the resorption of the alveolar ridge(AU)

New progress in the clinical application of GBR membrane materials / 口腔疾病防治

@#Guided bone regeneration (GBR) barrier membranes are of great significance for the reconstruction of the health and function of different periodontal tissues. Biocompatibility, spatial maintenance, closure, controllability and biological activation are the main criteria that should be met by these membranes. Artificial barrier membrane biomaterials can be divided into synthetic polymer materials, natural polymer materials and metals. According to their degradation characteristics, these membranes can be divided into two categories, absorbable and nonabsorbable membranes. GBR used for horizontal bone increments can be used to treat various types of bone defects, including the treatment of bone fenestration and bone cracking. The use of a non-absorbable e-PTFE membrane or absorbable collagen membrane can achieve the expected effect. However, for incremental or vertical bone growth at the alveolar crest, the use of this membrane is very challenging and requires good strength to maintain the osteogenic space. This space can be enhanced with e-PTFE or d-PTFE membranes with stable morphology, or absorbable membranes can be covered with titanium plates or meshes to achieve vertical bone increments. Currently, bioactive membranes, digital 3D-printed titanium membranes and piezoelectric active biological membranes are research hotspots. In future research, the biological activation of these membranes will be further improved, which will promote the development of artificial membranes in the next stage.

Biodegradation properties of multi-laminated small intestinal submucosa / 北京大学学报(医学版)

OBJECTIVE@#To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics.@*METHODS@#The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility.@*RESULTS@#In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time.@*CONCLUSION@#In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.

Guided bone regeneration using preformed titanium mesh combined with bioabsorbable membranes in aesthetic area / 中国组织工程研究

BACKGROUND: Absorbable and non-absorbable barrier membranes have their own merits and demerits in the guided bone regeneration. OBJECTIVE: To investigate the clinical effect of new preformed titanium mesh combined with different bone augmentation materials in anterior teeth with inadequate bone volume for dental implants. METHODS: Thirty-one patients with single maxillary anterior tooth loss were divided into three groups: Bio-Gide collagen membrane + Bio-oss bone group (C; n=12), titanium mesh + Bio-Gide collagen membrane + Bio-Oss bone group (TC; n=10), titanium mesh + concentrated growth factor + Bio-Gide collagen membrane + Bio-Oss bonegroup (TCC; n=9). Through clinical review, cone-beam CT and histological examination, osteogenic effects of the three treatment methods were compared and statistically analyzed at 0 day and 6 months after operation. The implementation of the study protocol complied with the relevant ethical requirements of Qingdao Stomatological Hospital, and each patient was fully informed of the trial process. RESULTS AND CONCLUSION: In the postoperative review, only two patients in the TC group had wound deformations, and the wound healed about 3 weeks postoperation. Six months after the operation, cone-beam CT results revealed significant differences in bone height between the TCC and TC groups and the C group (P < 0.05), as well as in bone width at the mark points of 2, 4 and 6 mm (P < 0.05). There was no significant difference in bone width between three groups at the mark point of 8 mm (P < 0.05). Hematoxylin-eosin staining of bone tissue around the implant showed that trabecular structure was visible in all three groups, but the structures was more mature and denser in the TCC group and sparser in the C group. These findings indicate that titanium mesh has good space maintenance function, better maintains the stability of bone graft material, and enhances the osteogenesis effect to a certain extent. Concentrated growth factors may promote soft tissue healing.

Guided bone regeneration combined with kidney-tonifying therapy for repairing femoral bone defect in rats / 中国组织工程研究

BACKGROUND: Guided bone regeneration technology, as a most widely used method for repairing bone defects, has been extensively used in the field of stomatology. However, there are few reports on the guided bone regeneration technology in long bone defects. OBJECTIVE: To explore the effects of guided bone regeneration combined with kidney-tonifying therapy on the repair of femoral bone defects in rats, and investigate its osteogenic efficacy and underlying mechanism. METHODS: Thirty-six Sprague-Dawley rats were randomly divided into six groups: blank group, guided bone regeneration group, high-, moderate-, and low-dose kidney-tonifying groups, and ossotide tablets group. The femur bone defect model of rats was established, and was treated by guided bone regeneration except for blank group. Bio-Gide collagen membrane combined with autologous bone was implanted by guided bone regeneration. The kidney-tonifying groups were given 0.216, 0.108 and 0.054 g/(kg•d) Qianggu capsule via gavage for 8 weeks. The ossotide tablets group was given 0.58 mg/(kg•d) ossotide tablets via gavage for 8 weeks. At 12 weeks after surgery, the osteogenesis was evaluated by X-ray examination, hematoxylin-eosin staining and Masson staining of bone tissue. The mRNA expression levels of alkaline phosphatase, Runx-2, vascular endothelial growth factor and bone morphogenetic protein-2 in bone tissues were detected by quantitative real-time RT-PCR. RESULTS AND CONCLUSION: Results of X-ray examination and hematoxylin-eosin staining and Masson staining of bone tissue showed that the scores of Lane Sandhu and Huddleston in each group were significantly higher than those in the blank group (P < 0.001). The scores in the high-and moderate-dose kidney-tonifying groups were significantly higher than those in the guided bone regeneration group (P < 0.01). RT-PCR results showed that the mRNA expression levels of alkaline phosphatase, Runx-2, vascular endothelial growth factor and bone morphogenetic protein-2 in bone tissue in the high-and moderate-dose kidney-tonifying groups were significantly higher than those in the blank group (P < 0.01), and were superior to the guided bone regeneration group (P < 0.05). In summary, guided bone regeneration combined with kidney-tonifying can significantly promote the repair of femoral bone defects, reduce bone absorption and improve osteogenic efficacy in rats. The mechanism of promoting bone regeneration and angiogenesis may be by up-regulating the expression of related osteogenic factors and angiogenic factors in the environment where the membrane barrier creates a dominant growth of bone tissue.