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.

Effect of a space stabilizing device on the capacity for osteogenesis in the bone-grafted area / 口腔医学

Objective@#To study the effect of a space stabilizing device on the capacity for osteogenesis in the bone-grafted area. @*Methods@#Patients with anterior teeth defects as well as labial alveolar ridge defects were randomly divided into two groups: the experimental group was treated using a space stabilization device after guided bone regeneration whereas the control group received regular guided bone regeneration. The CBCT data was analyzed prior to, immediately and 6 months after procedure to compare the osteogenesis with or without the device.@*Results@#Seventeen bone-grafted sites were examined(7 in the experimental group and 10 in the control group). At 2 mm and 4 mm below the alveolar ridge, the horizontal bone resorption rate in the experimental group was significantly lower than the corresponding level in the control group(P=0.001). The horizontal bone resorption rate at 2 mm below the alveolar ridge of each group was significantly higher than that at 4 mm below the alveolar ridge in corresponding groups(P=0.003). @*Conclusion@#The space stabilizing device used in this study has a positive clinical impact on preserving space stability and minimizing bone resorption.

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.

Desarrollo de sitio periimplantario mediante regeneración ósea guiada e injerto conectivo en el sector anterior / Peri-implant Site Development using Guided Bone Regeneration and Connective Tissue Graft in the Anterior Region

Condiciones desfavorables del reborde alveolar debido a atrofia, enfermedad periodontal o traumatismos pueden generar deficiencias de volumen óseo, produciendo como consecuencia una relación corona/implante inadecuada y un aspecto estético desfavorable. La presente serie de casos propone el uso de la técnica asociada a un injerto de tejido conectivo como método de desarrollo de sitio periimplantario, con el fin de corregir deficiencias del reborde alveolar, para permitir la posterior instalación de un implante óseo integrado. Ocho pacientes con indicación de extracción de una pieza anterior, asociada a ausencia de la tabla vestibular y a una pérdida de tejidos duros y blandos, fueron sometidos a un procedimiento de regeneración ósea guiada mediante el uso de una mezcla de xenoinjerto y hueso autólogo en conjunto con una membrana reabsorbible e injerto conectivo autólogo. A los 6 meses postratamiento, fue colocado el implante, y provisionalizado inmediatamente. En todos los casos se logró una mejora y una equiparación de los contornos periimplantarios con las piezas vecinas. No existieron complicaciones posoperatorias, la regeneración de tejidos fue exitosa en todos los casos intervenidos, y todos los implantes se integraron correctamente. La regeneración ósea guiada en conjunto con un injerto de tejido conectivo fue un método efectivo para el desarrollo de sitio periimplantario previo a la colocación de implantes en el sector anterior del maxilar.

Unfavorable conditions of the alveolar ridge, due to atrophy, periodontal disease or trauma, can lead to osseous volume deficiencies, producing an inadequate crown / implant relationship and an unfavorable esthetic appearance. The present case series proposes the use of guided bone regeneration (GBR) associated with a connective tissue graft, as a method for peri-implant site development, to correct alveolar ridge deficiencies, and to allow the subsequent placement of an osseointegrated implant. Eight patients with the indication of an anterior tooth extraction, associated with a loss of the vestibular plate and a hard and soft tissue deficiency, were treated with a GBR procedure using a mixture of xenograft-autogenous bone in conjunction with a resorbable membrane and an autogenous connective tissue graft. At 6 months post-treatment, the implant was installed and immediately provisionalized. In all the cases, an improvement and matching of the tissue contours with the neighboring teeth was achieved. There were no postoperative complications. The tissue regeneration was successful in all the cases, and all the implants achieved a correct integration. GBR, in conjunction with a connective tissue graft, was an effective method to perform a peri-implant site development prior to the implant installation in the maxillary anterior region.

Regeneración ósea guiada para el aumento vertical del reborde alveolar / Guided osseous regeneration for the vertical augmentation of the alveolar ridge

Se considera como aumento óseo vertical, cualquier técnica que apunte a crear una mayor altura del reborde alveolar. A inicios de la década de los 90’s se empezó a utilizar la regeneración ósea guiada (ROG) en mandíbulas atróficas, con el fin de permitir la instalación de implantes óseointegrados. Con el fin de evaluar y exponer parte de la evidencia disponible en la actualidad, con respecto a la ROG para aumento óseo vertical, se realizó la siguiente revisión bibliográfica.

Any technique aimed to improve the alveolar ridge height is considered as a vertical bone augmentation procedure. In the early 90’s guided bone regeneration (GBR) procedures began to be used in atrophic mandibles to allow the installation of osseointegrated dental implants. The following bibliographic review was made with the purpose of evaluating and exposing part of the available evidence at present in this field.

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.

Effects of dehydroepiandrosterone on amino acids receptor subunit NR2B and GBR1 expressed in primary cultured rat cerebral cortical neurons / 中国药理学通报

Aim To investigate the effect of dehydroepiandrosterone(DHEA)on the levels of NR2B and GBR1 expressed in primary cultured rat cerebral cortical neurons.Methods Primary cultured rat cerebral cortical neurons were treated with DHEA of different concentrations (1,10,100 μmol·L~(-1))and the expression of amino acids receptor subunit NR2B and GBR1 were detected by immunocytochemistry.Results Compared with control group,the expression intensity of NR2B increased by 15.6%,19.9% and 49.4% after DHEA-L,DHEA-M and DHEA-H treatment(P<0.05 or P<0.01);the expression intensity of GBR1 increased by 14.5% and 58.5% after DHEA-M and DHEA-H treatment(P<0.05 or P<0.01).Conclusion DHEA can enhance the expression of neuron receptor subunit NR2B and GBR1.

The effect of human demineralized freeze-dried xenograft on vertical bone formation in beagle dogs / 대한치주과학회지

PURPOSE: The purpose of this study was to evaluate exophytically vertical bone formation in the mandibular premolar area of beagle dogs by the concept of guided bone regeneration with a titanium reinforced e-PTFE membrane combined with human demineralized freeze-dried bone. MATERIALS AND METHODS: Four one-year old beagle dogs were divided into control and experimental group. All mandibular premolars were extracted and surgical vertical defects of 5 mm in height were created in the extracted sockets. At 8 weeks after the extraction, TR e-PTFE membrane sized with 8 mm in length, 5 mm in width, and 4 mm in height was placed on the decorticated mandible, fixed with metal pins and covered with full-thickness flap and assigned as control group. In experimental group, decorticated mandibule was treated with TR e-PTFE membrane and human demineralized freeze-dried bone. The animals were sacrificed at 16 weeks after the regenerative surgery, and new bone formation was assessed by histomorphometric as well as statistical analysis. RESULTS: Average of new bone formation was 38% in the control group, whereas was 25% in the experimental group (p<0.05). Average of connective tissue formation was 42% in the experimental group, whereas was 30% in the control group (p<0.05). The lamellar bone formation with haversian canals was observed in the both groups. In the experimental group, the particles of human demineralized freeze-dried bone were observed after 16 weeks and complete resorption of graft was not observed. CONCLUSION: On the basis of these findings, we conclude that titanium reinforced e-PTFE membrane may be used alone for vertical guided bone regeneration, but demineralized freeze-dried bone has no additional effect on vertical guided bone regeneration.

Bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs : pilot study / 대한치주과학회지

PURPOSE: Guided bone regeneration(GBR) has emerged as a treatment in the management of osseous defects associated with dental implants. But several studies have reported different degrees of success of guided bone regeneration, depending upon the type of barrier selected, presence or absence of an underlying graft material, types of graft material, feasibility of technique, and clinician's preference. The aim of the present study was to evaluate bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs. MATERIAL AND METHODS: Standardized buccal dehiscence defects(3x5 mm) were surgically 2 Mongrel dog's mandibles, each 8 SLA surface, 8 anodizing surface implants. Each buccal dehiscence defect received flap surgery only(no treatment, control), Cytoflex(R) membrane only, Resolut XT(R) membrane only, Resolut XT(R)+Osteon(TM). Animals were sacrificed at 8 weeks postsurgery and block sections were harvested for histologic analysis. RESULTS: All experimental group resulted in higher bone formation than control. Resolut XT(R)+Osteon(TM) group resulted appeared highest defect resolution. There was no difference between SLA and anodizing surface, nonresorbable and resorbable membrane. CONCLUSION: GBR results in rapid and clinically relevant bone closure on dehiscence defects of the dental implants.

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.

Guided bone regeneration using Regenaform(R) and Ossix(R) membrane: three case reports

This case study investigated the clinical effect of guided bone regeneration (GBR) using Regenaform(R) and Ossix(R) membrane and the histology of the new bone that formed just under the membranes. Regenaform(R) transplantation and covering with Ossix(R) membrane were performed to repair bone defects around implants after implantation in three patients. After 3-4 months, the membranes were removed in a second operation, and a biopsy was taken under the membrane. The biopsies showed a bone density of 23-42percent, and subsequent prosthetic treatments were successful in all cases.

Effect of inorganic polyphosphate on guided bone regeneration / 대한치주과학회지

This study was performed to evaluate the effect of inorganic polyphosphate on bone formation in the calvaria of rabbit in the procedure of guided bone regeneration with bovine cancellous bone graft and titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group I used only TR-ePTFE membrane, control group II used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in saline, experimental group III and IV used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 1% or 2% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 12 rabbits with titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in saline or inorganic polyphosphate. The animals were sacrificed at 2 weeks, 4 weeks, and 8 weeks after the surgery. Decalcified and non-decalcified specimens were processed for histologic and immunohistochemistric analysis. 1. Titanium reinforced ePTFE(TR-ePTFE) membrane showed good spacemaking and cell occlusiveness capability, but it showed poor wound stabilization. 2. The deproteinized bovine bone mineral did not promote bone regeneration, but it acted as a space filler. 3. There was no complete resorption of the deproteinized bovine bone mineral within 8 weeks. 4. 1% inorganic polyphosphate did not promote bone formation, but 2% inorganic poly- phosphate promoted bone formation. Within the above results, 2% inorganic polyphosphate could be used effectively for bone regeneration.

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.

Effect of deproteinized bovine bone mineral on cell proliferation in the procedure of guided bone regeneration / 대한치주과학회지

One of the bone substitutes now in routine use, deproteinized bovine bone mineral(DBBM), is regarded as resorbable and osteoconductive, but some studies refute this. The present study was performed to evaluate the effects of DBBM on guided bone regeneration using titanium membrane on the calvaria of rabbit. At 2 weeks, 4 weeks, 8 weeks, and 12 weeks after surgery, the animal was scrificed. Non-decalcified specimens were produced for histologic analysis. The results of this study were as follows: 1. Titanium membrane was biocompatible and capable of space-maintaining, but there was ingrowth of soft tissue through the pore of titanium membrane. 2. There was no resorption or reduction of DBBM with time. 3. Some of the DBBM particles were combined with newly formed bone. But, apart from host bone, a great part of the particles were surrounded by connective tissue. 4. The bone formation was slight vertically and restricted to superficial area of host bone. Whithin the above results, DBBM dose not appear to contribute to bone formation. DBBM may disturb the migration and proliferation of mesenchymal cell derived from host bone and increase the growth of connective tissue. Therefore, careful caution is needed on selection of bone graft material and surgical protocol at guided bone regeneration for implant placement.

Effect of pore number of titanium mesh on Bone Formation in the procedure of GBR / 대한치주과학회지

This study was performed to evaluate bone formation in the calvaria of rabbit by the concept of guided bone regeneration with titanium mesh membrane. Two different titanium meshes with varying number (353, 565) of pore were utilized in the study. Two surgical sites(T353, T565) were evaluated about whether or not the number of pore may have effect on the bone formation. The animal was sacrificed at 10days, 3 weeks, 6weeks, and 8 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis. 1. Titanium mesh was biocompatible and capable of maintaining the spacemaking. 2. At 3 weeks, 6 weeks, and 8 weeks after GBR procedure, bone formation was more in the T353 site than in the T565 site. 3. Soft tissue layer above the regenerated bone was better developed in the T565 site. 4. There was no difference between two membranes in bone maturity with time. Within the above results, titanium mesh with lesser pore in number might be recommended for the early bone formation.

Effect of Teflon Membrane and Nylon Membrane on Guided Bone Regeneraton in Rabbit Tibia

The purpose of present study is comparing the effect of Teflon Membrane and Nylon Membrane on bone regeneration in rabbit tibia. The 6 defects of 8x8x5mm size were drilled with dental handpiece in rabbit tibia, which on left side as an order of Control group(no coverage), Group 1(Nylon 5 micrometer size), Group 3(Nylon 10 micrometer size), and on right side Control group, Group 2(5 micrometer Teflon), Group 4(10 micrometer Teflon). Animals were killed at 7, 10, 14, 42 days to make specimens and observed the difference of healing potentials with light microscopy. The results were as follows ; 1. New bone formation has taken place at 14 days in Guided Bone Regeneration (GBR) group comparing to the Control group of massive inflammatory status. 2. Larger pore membrane allows more favorable healing potentials. Bone formation started earlier in larger membrane pore groups than smaller groups, until 14 days. 3. Bone forming potentials of Teflon membrane group was higher than Nylon membrane groups, Control group has the lowest bone forming potentials. 4. New bone formation was almost ended in 42 days, and there was no difference of bone formation between Nylon and Teflon membrane group of different size. There was no difference of bone formation at final stage(42 days) between Nylon membrane and Teflon membrane of same pore size. So nylon membrane may be clinically usable in guided bone regeneration case with further studies.