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.

Atraumatic Extraction and immediate implant placement into infected site with the "ice cream cone" technique and L-PRF: A Case Report

ABSTRACT: We describe a case report of a 53 years old patient with osteopenia treatment, which presented a longitudinal root fracture in relation to 9 tooth Single Fixed Prothesis (SFP), an active fistula and a bucal plate loss. It was prescribed the tooth extraction and the immediate Biohorizons® Tapered Internal® implant installation. The regeneration of the bucal plate was performed using the technique of "ice cream cone" using Mineross®, Mem Lok® and L-PRF.

Histomorfometría de la regeneración ósea obtenida con sistema liposoma-membrana de quitosano en un modelo experimental

RESUMEN Introducción: desarrollamos un andamiaje a base de quitosano en dos formas físicas, membrana y liposoma como biomateriales para Regeneración ósea guiada no estudiado histológicamente en modelo experimental. Objetivo: determinar histológicamente la eficiencia del quitosano para la regeneración ósea guida en defectos óseos creados en tibias de ratas del linaje Wistar. Materiales y Métodos: esta investigación fue realizada en 25 ratas Wistar machos, adultas con peso entre 350 g - 500 g, a los cuales se les creó un defecto longitudinal en ambas tibias (control y experimental). Los animales fueron divididos al azar en 3 grupos: 9 ratas que fueron evaluadas a las 3 semanas, 8 que fueron valoradas a las 6 semanas y 8 a las 9 semanas. Resultados: los hallazgos histológicos confirmaron que existía mayor actividad osteoinductiva y mayor nivel de madurez ósea en las tibias experimentales a diferencia del grupo control. Conclusiones: el liposoma de quitosano fue eficiente para la regeneración ósea guiada promoviendo mayor regeneración ósea en menor tiempo que en el grupo control.

ABSTRACT Introduction: We developed a chitosan scaffold in two physical forms, membrane and liposome as biomaterials for guided bone regeneration, which has not been studied histologically in an experimental model. Objective: To determine histologically the efficiency of chitosan in the guided bone regeneration in bone defects created in tibias of Wistar rats. This study was performed in 25 male adult Wistar rats with weight between 350 g - 500 g. A longitudinal defect was created in both tibias (control and experimental). The animals were randomly divided into 3 groups: 9 rats were evaluated at 3 weeks, 8 at 6 weeks and 8 at 9 weeks. Results: The histological findings confirmed that there was more osteoinductive activity and a higher level of bone maturity in the experimental tibias than in the control group. Conclusions: The chitosan liposome was efficient in the guided bone regeneration promoting more bone regeneration in less time in the experimental group than in the control group.

Guided bone regeneration using two types of non-resorbable barrier membranes

INTRODUCTION: Guided bone regeneration (GBR) is a common procedure for the treatment of bone defects and bone augmentation. The non-resorbable barriers are well-documented barriers for GBR because of their stability and malleability. However, few GBR studies have focused on the different types of non-resorbable barriers. Therefore, this study examined the clinical results of different non-resorbable barriers for GBR; expanded polytetrafluoroethylene (e-PTFE) (TR-Gore Tex, Flagstaff, AZ, USA), and high-density polytetrafluoroethylene (d-PTFE) (Cytoplast membrane, Oraltronics, Bremen, Germany). MATERIALS AND METHODS: The analysis was performed on patients treated with GBR and implant placement from January 2007 to October 2007 in the department of the Seoul National University Bundang Hospital. The patients were divided into two groups based on the type of non-resorbable barrier used, and the amount of bone regeneration, marginal bone resorption after prosthetics, implant survival rate and surgical complication in both groups were evaluated. RESULTS: The implants in both groups showed high survival rates, and the implant-supported prostheses functioned stably during the follow-up period. During the second surgery of the implant, all horizontal defects were filled with new bone, and there was no significant difference in the amount of vertical bone defect. CONCLUSION: In bone defect areas, GBR with non-resorbable barriers can produce favorable results with adequate postoperative management. There was no significant difference in bone regeneration between e-PTFE and d-PTFE.

The effect of maintenance period of non-resorbable membrane on bone regeneration in rabbit calvarial defects / 대한치주과학회지

When clinicians faced with an insufficient volume of supporting bone on ideally esthetic and biomechanical position for dental implantation, guided bone regeneration(GBR) was indicated. Although GBR has wide application at clinic, proper time of membrane removal remains qustionable in using non-resorbable membrane, such as non-expanded polytetrafluoroethylene(PTFE). The aim of this study was to compare the effect of maintenance period of PTFE membrane on bone regeneration in rabbit calvarial defects. Eight adult New Zealand white female rabbits were used in this study. Four defects were surgically made in their calvaria. Using a trephine bur, 4 'through and through' defects were created and classified into 3 groups, which were consisted of control group(no graft), experimental group 1(autogenous bone)and experimental group 2(deproteinized bovine bone; OCS-B(R)). The defects were covered with PTFE membrane(Cytoplast(R)). Membranes were removed after 1, 2, 4 and 8 weeks post-GBR procedure in 2 rabbits repectively. All rabbits were sacrificed after 8 week post-GBR procedure. Specimens were harvested and observed histologically. The results were as follow; 1) The use of graft material and membrane was necessary in GBR procedure. 2) When PTFE membranes were removed early, the most favorable bone regeneration was revealed in experimental group I, followed by experimental group II and control group. 3) On GBR, it is recommended that membrane should maintain for 4 weeks with autogenous graft. As well, the use of xenograft need longer maintenance period than autogenous bone. Further evaluations will be needed, such as histomorphologic research, more species and different kinds of graft materials. And on the basis of these studies, clinical researches would be required.

Development of a bioactive cellulose membrane from sea squirt skin for bone regeneration - a preliminary research

OBJECTIVES: To develop a bioactive membrane for guided bone regeneration (GBR), the biocompatibility and bone regenerating capacity of the cellulose membrane obtained from the Ascidians squirt skin were evaluated. MATARIALS AND METHODS: After processing the pure cellulose membrane from the squirt skin, the morphological study, amino acid analysis and the immunoreactivity of the cellulose membrane were tested. Total eighteen male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into two control (n=8) and another two experimental groups (n=10). In the first experimental group (n=5), the cellulose membrane was applicated to the 8.0 mm sized calvarial bone defect and the same sized defect was left without cellulose membrane in the first control group (n=4). In the another experimental group (n=5), the cellulose membrane was applicated to the same sized calvarial bone defect after femoral bone graft and the same sized defect with bone graft was left without cellulose membrane in the another control group (n=4). Each group was sacrificed after 6 weeks, the histological study with HandE and Masson trichrome stain was done, and immunohistochemical stainings of angiogenin and VEGF were also carried out. RESULTS: The squirt skin cellulose showed the bio-inductive effect on the bone and mesenchymal tissues in the periosteum of rat calvarial bone. This phenomenon was found only in the inner surface of the cellulose membrane after 6 weeks contrast to the outer surface. Bone defect covered with the bioactive cellulose membrane showed significantly greater bone formation compared with control groups. Mesenchymal cells beneath the inner surface of the bioactive cellulose membrane were positive to the angiogenin and VEGF antibodies. CONCLUSION: We suppose that there still remains extremely little amount of peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx. This composition could prevent the adverse immunological hypersensitivity and also induce bioactive properties of cellulose membrane. These properties induced the effective angiogenesis with rapid osteogenesis beneath the inner surface of cellulose membrane, and so the possibilities of clinical application in dental field as a GBR material will be able to be suggested.