Research progress on anterior alveolar bone changes after orthodontic treatment involving extractions / 口腔疾病防治

@#It has been traditionally believed that a 1:1 cortical bone remodeling/tooth movement ratio has been preserved during orthodontic treatment for tooth movement, with the alveolar bone on the tension side growing and the alveolar bone on the pressure side resorbing to maintain the balance of the alveolar bone. However, recent studies have shown that alveolar bone loss has been found in patients who have undergone orthodontic treatment, suggesting that the alveolar bone does not change as the teeth change over time. Whether the morphology of the alveolar bone will change when the anterior teeth are moved has been the clinical focus. The changes of anterior alveolar bone in patients who have undergone tooth extraction after orthodontic treatment were summerized by literature review in this paper. The results of the review showed that the alveolar bone at the lingual/palatal root-cervical site of the anterior root is more prone to bone loss after extensive movement of the anterior teeth. With the development of imaging technology, CBCT is now more commonly used for analysis instead of two-dimensional images for measurement, as its results are more accurate. However, there are few multifactorial studies in which CBCT has been used to assess the morphological changes in the alveolar bone. The focus of future research is to compare the long-term changes in the anterior alveolar bone of patients of different ages based on three-dimensional imaging, and to study the correlation between different skeletal features, tooth movement patterns and alveolar bone remodeling.

Sinus floor elevation using a new bovine bone grafting material: case report and bone grafting materials update / Actualización en materiales de relleno óseo: reporte de un caso clínico de elevamiento del piso del seno maxilar usando un nuevo material de relleno óseo bovino

Bone grafting is important to preserve the alveolar bone ridge height and volume for dental implant placement. Even though implant-supported overdentures present highly successful outcomes, it seems that a great number of edentulous individuals have not pursued implant-based rehabilitation. The cost of the treatment is one of the reasons of discrepancy between highly successful therapy and its acceptance. Therefore, the development of biomaterials for bone grafting with comparable characteristics and biological effects than those renowned internationally, is necessary. In addition, domestic manufacture would reduce the high costs in public health arising from the application of these biomaterials in the dental feld. The purpose of this clinical case report is to provide preliminary clinical evidence of the efficacy of a new bovine bone graft in the bone healing process when used for sinus floor elevation. (AU)

El uso de injertos óseos es importante para preservar la altura y el volumen de la cresta alveolar para la colocación de implantes dentales. Si bien las sobredentaduras implanto-soportadas presentan resultados altamente exitosos, la mayoría de las personas desdentadas no han sido rehabilitadas mediante implantes dentales. Uno de los principales motivos por los cuales los pacientes no aceptan este tipo de tratamiento, altamente exitoso, es el elevado costo del mismo. Por ello, es necesario el desarrollo de biomateriales de injerto óseo con características y efectos biológicos comparables a los reconocidos internacionalmente. Asimismo, la fabricación nacional reduciría los altos costos en Salud Pública derivados de la aplicación de estos biomateriales en el campo dental. El objetivo de esta comunicación es presentar un caso clínico a fin de proporcionar evidencia preliminar acerca de la eficacia de un nuevo injerto de hueso bovino en el proceso de cicatrización ósea en el levantamiento del piso del seno maxilar. (AU)

Comparison of morphological quantitative characteristics of the newly formed alveolar bone after the application of demineralized bone matrix and cortical bone allografts / Comparación de las características morfológicas cuantitativas del hueso alveolar recién formado después de la aplicación de matriz ósea desmineralizada y aloinjertos de hueso cortical

The allografts were used to obtain sufficient alveolar bone tissue for proper dental implant placement. The objective of the present study was to evaluate the morphological and quantitative characteristics (cellular and collagen densities) of the newly formed alveolar bone with the application of cortical bone (CB) and demineralized bone matrix (DBM) allografts. Six samples of alveolar bone tissue from 5 patients (50 ± 6.3 years) were obtained after 6 months of application of the allografts and immediately before the placement of the dental implants. The samples were fixed (buffered formaldehyde, pH7.2), decalcified (EDTA 10 %) and histologically processed (HE and Picro-Sirius) for histologic analysis. Morphological analysis revealed presence of osteocytes and trabeculae in neoformed bone tissue near the allografts and absence of inflammatory and allergic cells; the remnants of CB were located mainly in the periphery of the bone tissue and the remnants of DBM were more incorporated into the tissue. Osteogenitor cells were observed around the remaining material. The cell density was not modified in newly formed bone tissue with the application of both allografts as compared to mature bone tissue. The density of the type I and III collagens present in the osteoids interspersed with the remainder of the materials showed a tendency to increase in the samples treated with DBM. It was concluded that by the histological characteristics observed both grafts were biocompatible, however the bone treated with DBM presented better incorporation and a tendency of increase of the collagen content in the remnant region of the allografts.

Los aloinjertos son utilizados para obtener tejido óseo alveolar apropiado para la colocación correcta del implante dental. El objetivo de este trabajo fue evaluar las características morfológicas y cuantitativas (densidades celulares y de colágeno) del hueso alveolar recién formado con la aplicación de aloinjertos de hueso cortical (CB) y matriz desmineralizada de hueso (DBM). Seis muestras de tejido óseo alveolar fueron obtenidas de 5 pacientes (50 ± 6,3 años) después de 6 meses de aplicación de los aloinjertos e inmediatamente antes de la colocación de los implantes dentales. Las muestras fueron fijadas (formaldehído tamponado, pH 7,2), descalcificadas (EDTA al 10%) y procesadas histológicamente (HE y Picro-Sirius) para el análisis histológico. El análisis morfológico reveló la presencia de osteocitos y trabéculas en el tejido óseo neoformado cerca de los aloinjertos y la ausencia de células inflamatorias y alérgicas; los remanentes de CB se ubicaron principalmente en la periferia del tejido óseo y los remanentes de DBM se incorporaron más en el tejido. Se observaron células osteogenitoras alrededor del material restante. La densidad celular no se modificó en el tejido óseo recién formado con la aplicación de ambos aloinjertos en comparación con el tejido óseo maduro. La densidad de los colágenos de tipo I y III presentes en los osteoides intercalados con el resto de los materiales mostró una tendencia a aumentar en las muestras tratadas con DBM. Se concluyó que, debido a las características histológicas observadas, ambos injertos fueron biocompatibles, sin embargo, el hueso tratado con DBM presentó una mejor incorporación y una tendencia al aumento del contenido de colágeno en la región remanente de los aloinjertos.

Protective effect of LiCl-activated Wnt/β-catenin signaling pathway on glucocorticoid-induced osteoporosis / 第二军医大学学报

Objective To investigate the protective effect of lithium chloride (LiCl)-activated Wnt/beta-catenin signaling pathway on glucocorticoid-induced bone loss. Methods C57BL6/J mice were randomly divided into 3 groups. osteoporosis (OP) group and LiCl group were injected intraperitoneally once daily with dexamethasone (50 mg kg). while control group was injected with normal saline. LiCl group was given LiCl (200 mg kg) through water administration. After 5 weeks of treatment, mice were sacrificed within 24 h. Anti-active hela-catenin antibody was used in immuno his to chemical staining to detect the activity of Wnt/beta-cat enin signaling pathway, tone morphology was observed by UK siaining. Meanwhile. bone histomorphometrical parameters were analyzed by microCT. Bone formation and bone resorption of different groups were detected by calcein labeling and TRAP siaining. respectively. Results The protein level of active beta-calenin was higher in LiCl group compared with OP group, tone histomorphometrical parameters including the trabecular bone volume as a percentage of total volume (BV/TV). bone mineral density (HMD), trabecular number (Tb. N) and trabecular space (Tb. Sp) were all significantly improved in LiCl group- even though obvious difference existed lieiween LiCl group and control group (P<0. 05). Calcein labeling showed that new hone formation was markedly improved in LiCl group, but was still lower than that in control group, tone resorption was not significantly changed among three groups as indicated by TRAP siaining. Conclusion LiCl administration effectively activates Wnt/β-catenin signaling pathway in vivo* which improve new bone formation and rescue glucocorticoid-induced bone loss.

Effects of Block Bone Substitutes Loaded with Escherichia Coli-Produced Recombinant Human Bone Morphogenetic Protein-2 on Space Maintenance and Bone Formation in Rat Calvarial Onlay Model

We aimed to evaluate the effects of onlay-type grafted human freeze-dried corticocancellous bone block (FDBB) and deproteinized bovine bone with collagen (DBBC) loaded with Escherichia coli-produced recombinant human bone morphogenetic protein-2 (ErhBMP-2) on space maintenance and new bone formation in rat calvaria. Collagen sponge (CS), FDBB, or DBBC disks (8×4 mm) with ErhBMP-2 (2.5 µg) were implanted onto the calvaria of male Sprague-Dawley rats, whereas CS with buffer was implanted onto the calvaria as controls (n=20/carrier). Rats were killed at 2 or 8 weeks post-surgery for histologic and histomorphometric analyses; total augmented area, new bone area, and bone density were evaluated. At both time-points, all ErhBMP-2 groups showed significantly higher new bone area and bone density than the control group (p<0.05). ErhBMP-2/FDBB and ErhBMP-2/DBBC groups showed significantly higher total augmented area than ErhBMP-2/CS group (8 weeks), and ErhBMP-2/FDBB group showed significantly higher new bone area and bone density than ErhBMP-2/DBBC group (p<0.05). ErhBMP-2/CS group showed the highest bone density (p<0.05). Combining ErhBMP-2 with FDBB or DBBC could significantly improve onlay graft outcomes, by new bone formation and bone density increase. Moreover, onlay-grafted FDBB and DBBC with ErhBMP-2 could be an alternative to autogenous block onlay bone graft.

Effect of adipose derived stem cells on ovariectomised Wistar rats.

Background: Various clinical trials are going to determine the efficacy of human Adipose Derived Stem Cells (hADSCs) in the treatment of degenerative diseases including osteoporosis. Stem cell therapy for osteoporosis is aimed at inducing new bone formation by the proliferation and differentiation of bone progenitor cells. The therapeutic potential of hADSCs has to be investigated in animal models of osteoporosis before suggesting it as a therapeutic option. Methods: hADSCs were cultured in the Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 4 mM L-glutamine and 110 mg/l sodium pyruvate, 10% Fetal Bovine Serum (FBS), 1% penicillin–streptomycin and non-essential amino acids. For osteogenic differentiation of hADSCs, cells were cultured as above then were exposed to osteogenic induction medium for seven days. Intravenous infusion of osteogenesis induced hADSCs was given to 20 ovariectomised Wistar rats three months after ovariectomy (test group) and 20 ovariectomised rats were kept as controls. Rats were sacrificed 35 days after infusion and tibial cross sections at the level of tibio-fibular joint were stained with H&E & Masson’s trichrome. The digital slide images were viewed using Aperio Image Scope software. Results: The results showed that there was new bone formation in the test group, indicated by osteoid formation and osteoblasts. There was significant increase in the cortical thickness in the test group when compared with the control group. There was no significant increase in trabecular volume when compared to the control group. Conclusions: hADSCs after osteogenic induction may have the potential to enhance new bone formation and may be useful in the treatment of osteoporosis.

Digital radiographic evaluation of the midpalatal suture in patients submitted to rapid maxillary expansion.

Aims: To analyze the density of the midpalatal suture by means of digital radiographs three months after retention to evaluate if this period of retention is really sufficient for bone repair. Materials and Methods: This prospective study consisted of 31 patients (11 girls and 20 boys) in the mixed or permanent dentition stage, treated using a tooth-tissue borne expanders (Haas). Occlusal digital radiographs were taken at three stages: prior to rapid maxillary expansion (Stage I); immediately after desired maxillary expansion (Stage II); and after three months of retention (Stage III). Radiographs were taken on a dental X-ray machine, set at 70 kVp and 7 mA with an exposure time of 0.04 s. A phosphor storage plate system, imaging plate size n. 2 (35 × 45 × 1.6 mm), was used. Three regions (A, B and C) measured 0.02 mm² were selected for optical density analysis. The difference between the measurements was evaluated with the paired t-test. Results: The optical density was reduced at Stages II and III compared with Stage I. Between-stage comparison showed statistically significant changes for all variables (P < 0.05), with the highest mean optical density at Stage I and the lowest at Stage II, in all groups. Actually, there was an increase in optical density between Stages II and III, but they are reduced compared with Stage I. Conclusion: The results strongly suggest that bone formation did not occur as expected, and that a longer retention period for bone repair may be necessary.

The Effect of PRF and PRP for New Bone Formation of beta-TCP in Skull of White Rabbit

Remodelación ósea en espondiloartritis / Bone remodeling in spondyloarthritis

Las espondiloartropatías (EAS) corresponden a un grupo de patologías inflamatorias crónicas caracterizadas por proliferación ósea que progresivamente conduce a anquilosis y discapacidad funcional. Las alteraciones radiológicas observadas en dichos pacientes revelan cambios erosivos y sobrecrecimiento de estructuras óseas conocidas como sindesmofitos. Teniendo en cuenta la entesis como órgano primario de la enfermedad, varios procesos tienen lugar en este sitio anatómico: inflamación, destrucción ósea y finalmente nueva formación ósea. El proceso inflamatorio tiene como resultado un exceso de formación ósea, y el impacto neto depende de la localización, tipo celular, citoquinas y factores presentes en el micro ambiente local. Varias moléculas que actúan ya sea como moduladores inmunológicos o reguladores de la homeostasis del hueso, han sido implicadas en la mediación del imbalance entre reabsorción y formación que finalmente resulta en degeneración a nivel de la zona de entesis y/o articular. Modelos animales sugieren que la anquilosis articular que puede llegar a producirse puede ser independiente del Factor de Necrosis Tumoral Alfa; por lo tanto, el proceso de neoformación tisular puede ser considerado un blanco terapéutico adicional. La vía de señalización Wnt, considerada el principal regulador de osteoblastogénesis (Familia de glicoproteína Wnt), teniendo en cuenta su papel en cuanto a regulación del imbalance entre formación y resorción ósea, ha constituido un nuevo campo de investigación de gran interés durante los últimos años.

Spondyloarthritis are a group of chronic inflammatory diseases characterized by progressive new bone formation leading to ankylosis and functional disability. The radiographic changes in these patients may show erosive changes and overgrowth of bony structures called syndesmophytes. Given the enthesis as the primary organ of the disease, several processes take place: inflammation, bone destruction and finally new bone formation. The inflammatory process results in excess of bone formation and the impact depends on the location, cell type, cytokines and factors in the local microenvironment. Several molecules that act either as immune modulators or regulators of bone homeostasis have been implicated in mediating the imbalance between resorption and formation that ultimately results in joint degeneration. Animal models suggest that joint ankylosis may be independent of TNF alfa; therefore the process of new tissue formation can be an additional therapeutic target. The Wnt signaling pathway, considered the primary regulator of osteoblastogenesis and its role in terms of regulating the imbalance between bone formation and resorption, is a new research field of great interest in recent years.

Análise da densidade óptica da sutura palatina mediana seis meses após a expansão rápida da maxila assistida cirurgicamente / Evaluation of the midpalatal suture optical density six months after surgically assisted rapid maxillary expansion

OBJETIVO: avaliar a neoformação óssea da sutura palatina mediana por meio da análise de densidade óptica após a expansão rápida da maxila assistida cirurgicamente (ERMAC). MÉTODOS: a amostra estudada consistiu de 16 pacientes, sendo 6 do gênero masculino e 10 do gênero feminino. Todos os pacientes apresentavam atresia maxilar com mordida cruzada posterior e foram submetidos à ERMAC. Foram realizadas radiografias oclusais parciais da região dos incisivos superiores em quatro fases: antes da ERMAC (fase I), após o fim da ativação do parafuso expansor (fase II), três meses após a ativação do parafuso expansor (fase III), e seis meses após a ERMAC (fase IV). Uma escala de alumínio com oito degraus, variando de 1 a 8mm, foi adaptada no extremo das radiografias. A análise da densidade óptica foi feita após a digitalização das radiografias, utilizando-se o software Image Tool® (UTHSCSA, San Antonio, Texas, EUA). Em cada uma dessas fases, duas áreas foram selecionadas e analisadas. A região "A" (anterior) mediu 8 x 1mm² e localizou-se a 1,2cm da tangente situada nos incisivos centrais superiores na região da sutura palatina mediana. A região "B" (posterior) mediu 5 x 9mm² e localizou-se a 4,3cm da tangente situada nos incisivos centrais superiores na região da sutura palatina mediana. RESULTADOS: na região "A", comparando-se a fase I com a fase II, e a fase I com a fase III, foram encontradas diferenças estatisticamente significativas - p < 0,0001 e p < 0,0001, respectivamente -; comparando-se a fase I com a IV, e a fase II com a III, foram encontradas diferenças estatisticamente significativas - p = 0,0169 e p = 0,0004, respectivamente -; comparando-se as fases II e IV, e a fase III com a IV, diferenças estatisticamente significativas também foram encontradas - p < 0,0001 e p = 0,0023, respectivamente. Na região "B", comparando-se as fases I e II, e a fase I com a III, diferenças estatisticamente significativas foram encontradas - p < 0,0001 ...

AIM: This study evaluated the new bone formation in the midpalatal suture after surgically assisted rapid maxillary expansion by optical density analysis. METHODS: The sample was comprised by 16 patients (six males and ten females). All patients presented maxillary atresia with posterior crossbite and were submitted to SARME. Maxillary occlusal radiographs were taken at four stages (before SARME, immediately after SARME, three months after SARME and six months after SARME). An aluminium scale (step wedge) with eight steps varying from 1mm to 8mm was adapted at the end of the films. Optical density analysis was performed after digitization of radiographs using the Image ToolTM software (UTHSCSA, San Antonio, Texas, USA). Region A measured 8 x 1mm² and was located 1.2cm from the tangent to the maxillary central incisors at the region of the midpalatal suture. Region B measured 5 x 9mm² and was located 4.3cm from the tangent to the maxillary incisors at the region to the midpalatal suture. RESULTS: Statistical analysis of region A revealed statistically significant differences between phases I and II (p < 0.0001), and phases I and III (p < 0.0001); statistically significant differences between phases I and IV (p = 0.0169), and phases II and III (p = 0.0004); statistically significant differences between phases II and IV (p < 0.0001), and phases III and IV (p = 0.0023). In region B, there was statistically significant differences between phases I and II (p < 0,0001), and phases II and III (p < 0.0001); no statistically significant differences between phases I and IV (p = 0.1152); in phases II and III (p = 0.0002), phases II and IV (p < 0.0001) and phases III and IV (p = 0.0010) statistically significant differences were observed. CONCLUSIONS: Optical density analysis improves post-treatment control of SARME procedures by surgeons and orthodontists. After six months, new bone formation at the midpalatal suture is not complete in region "A" ...

A biologic study on toothash - plaster of paris mixture with absorbable collagen membrane in the treatment of peri-implant defects

Comparison on New Bone Formation Between Ovariectomized Rats and Normal Rats After Graft of Alloplastic bone material / 대한치과보철학회지

PURPOSE OF STUDY: To compare on bone formation between ovariectomized rats and normal rats after graft of alloplastic bone material. MATERIAL AND METHODS: Twenty female rats were used in this study. They were divided into two groups by each ten rats. One group was ovariectomized and grafted alloplastic bone material. Other group was non-ovariectomized and grafted alloplastic bone material. After a healing time of 4 weeks, the animals were sacrificed and decalcified preparations were routinely processed for histologic evaluations. RESULTS: Ovariectomy group was significantly lesser bone formation compared with non-ovariectomy group. CONCLUSIONS: Ovariectomy acts as a negative factor in new bone formation.

Mechanism of magnesium alloy degradation and bone formation in vivo / 中国矫形外科杂志

[Objective]To study the mechanism of magnesium alloy degradation and bone formation at the bone-implant interface after implanting a magnesium alloy into rat femur.[Method]SD rats femur were filled with magnesium alloy stick.Nine weeks later,animals were killed and femur were retrieved.Systematic investigations on the surface morphology,composition,structure of bone-implant were performed by means of metallurgical microscope,scanning electron microscopy(SEM),and energy dispersive spectrum(EDS).Decalcified sections were prepared,and histologic examination was carried out.[Result]The bone response happened both on the surface of surrounding bone and the surface of magnesium alloy degradation layer while magnesium alloy degradating in rat femur.It was formed three layers at the interface of bone-implant: the metal layer,the degradation layer,and the new bone layer.Discontinuity connective tissue could be seen on the new bone layer but no inflammatory cells were found.[Conclusion]The new bone response at the interface of bone-implant is consistent with normal bone tissue.Magnesium alloys have good characters of degradation ability,osteogenesis ability,and histocompatibility.And the rate of degradation is corresponding to the rate of new bone formation.

The effect of magnetism(Neodymium magnet) on bone formation around titanium implants inserted into the tibia of rabbit / 대한치과보철학회지

STATEMENT OF PROBLEM: There are many articles that showed that the magnetism affected the bone formation around titanium implant. It means that a proper magnetism made the osseointegration improved around the implant. So after additional research on the other effect of magnetism on bone formation in implant therapy, we can conclude its possibility of clinical application on implant treatment. PURPOSE: The purposes of this study were to find out the intensity of magnetic field where magnetism in the titanium implant specimen inserted into the bone could affect the bone formation, and to discover the possibility of clinical application in the areas of dental implants and bone grafts. MATERIAL AND METHOD: Ten adult male rabbits(mean BW 2Kg) were used in this study. Titanium implant specimens were surgically implanted on the mesial side of the tibia of rabbits. Neodymium magnets(Magnedisc 500, Aichi Steel Corp. Japan) were placed into the implants of experimental group except control group, just after placement of the titanium implants. At 2, 4 and 8 weeks after the surgery, the animals were sacrificed, specimens were obtained and stained with Hematoxylin-Eosin for light microscopic evaluation and histomorphometric analysis. CONCLUSION: The results were as follows: 1. In radiographic findings, increased radiopacity downward from crestal bone was observed along the titanium implant specimen at experimental period passed by 2,4, and 8 weeks in both control and experimental group. 2. In histoiogic findings, increased new bone formation was shown in both control and experimental group through the experiment performed for 2,4, and 8 weeks. More new bone formation and bone remodeling were shown in experimental group. 3. In histomorphometric analysis, the bone contact ratios were 11.9% for control group and 38.5% for experimental group(p<0.05).

The change of bone formation according to magnetic intensity of magnet placed into titanium implant specimens / 대한치과보철학회지

PURPOSE: The purposes of this investigation were to discover the possibility of clinical application in the areas of dental implants and bone grafts by investigating the bone formation histologically around specimen which was depending on the intensity of magnetic field of neodymium magnet inside of the specimens. MATERIAL AND METHOD: 1. Measurement of magnetic intensity - placed the magnet inside of the specimen, and measured the intensity of magnetic field around the 1st thread and 3rd thread of specimen 20 times by using a Gaussmeter(Kanetec Co., Japan). 2. Surgical Procedure - Male rabbit was anesthetised by constant amount of Ketamine (0.25ml/kg) and Rompun (0.25ml/kg). After incising the flat part of tibia, and planted the specimens of titanium implant, control group was stitched without magnet, while experimental groups were placed a magnedisc 500(Aichi Steel Co., Japan) or magnedisc 800(Aichi Steel Co., Japan) into it, fixed by pattern resin and stitched. 3. Management after the surgery. - In order to prevent it from the infection of bacteria and for antiinflammation, Gentamycin and Ketopro were injected during 1 week from operation day, and dressed with potadine. 4. Preparation of histomorphometric analysis - At 2, 4 and 8 weeks after the surgery, the animals were sacrificed by excessed Ketamine, and then, specimens were obtained including the operated part and some parts of tibia, and fixed it to 10% of PBS buffer solution. After embedding specimens in Technovit 1200 and B.P solution, made a H-E stain. Samples width was 75micrometer. In histological findings through the optical microscope and using Kappa image base program(Olympus Co. Japan), the bone contact ratio and bone area ratio of each parts of specimens were measured and analyzed. 5. Statistical analysis Statistical analysis was accomplished with Mann Whitney U-test. RESULTS AND CONCLUSION: 1. In histomorphometricl findings, increased new bone formation was shown in both control and experimental groups through the experiment performed for 2, 4, and 8 weeks. After 4 weeks, more osteoblasts and osteoclasts with significant bone remodeling were shown in experimental groups. 2. In histomorphometric analysis, the bone contact ratios were 38.5% for experimental group 1, 29.5% for experimental group 2 and 11.9% for control group. Experimental groups were higher than control group(p<0.05)(Fig. 6, Table IV). The bone area ratios were 60.9% for experimental group 2, 46.4% for experimental group 1 and 36.0 % for control group. There was no significantly ststistical difference between experimental groups and control group(p<0.05)(Fig. 8, Table VII) 3. In comparision of the bone contact ratios at each measurement sites according to magnetic ntensity, experimental group 2(5.6mT) was higher than control group at the 1st thread (p<0.05) and experimental group 1(1.8mT) was higher than control group at the 3rd thread(p<0.05)(Fig. 7, Table V, VI). 4. In comparision of the bone area ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group and experimental group 1(4.0mT) at the 1st thread(p<0.1) and experimental group 2(4.4mT) was higher than experimental group 1(1.8mT) at the 3rd thread(p<0.1)(Fig. 9, Table IX, X). Experiment group 2 was largest, followed by experiment group1 and control group at the 3rd thread of implant. There was a significant difference at the 1st thread of control group and experiment group 2. and at 1st thread and 3rd thread of experiment group 1 and 2, and not at control group experiment group 1.(p<0.1)

The Biological Effects of Calcium Phosphate Coated Implant for Osseointegration in Beagle Dogs / 대한치주과학회지

The influence of calcium phosphate (Ca-P) coating on the bone response of titanium implants was investigated two types of titanium implants, i.e. as -machined ,as -machined with Ca-P coating, were prepared. The Ca-P coating produced by OCT Inc technique. These implants were inserted into the left and right femur of beagle dog. After implantation periods of 3 days, 1weeks, weeks, 4weeks, 8weeks, 12weeks, 24weeks, the bone-implant interface was evaluated histologically, histomorphometrically, and removal torque. Histological evaluation revealed no new bone formation around different implant materials after 2weeks of implantation. After 4 weeks, Ca-P coated implants showed a higher amount of bone contact than either of the non coated implants. After 12weeks, bone healing was almost completed. And implant were removed by reverse torque rotation with torque-measuring device. Mean torque values for 4weeks control were 2.375Kgf.cm and experimental were 2.725Kgf.cm. And mean torque values for 8weeks control were 1.25Kgf.cm and experimental were 1.0Kgf.cm On the basis of these findings, we concluded that deposition of a Ca-P coating on an implant has a beneficial effect on the bone response to this implant during the healing phase. Besides implant surface conditions the bone response is also determined by local implant site condition.

The histological and immunohistochemical findings of the newly formed human bone after distraction osteogenesis

Postoperative Newbone Formation of Horizontal Semicircular Canal Fistulae in Chronic Otitis Media with Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVE: It is not uncommon to encounter labyrinthine fistulae during cholesteatoma surgeries. The aim of this study is to evaluate the postoperative changes of labyrinthine fistulae after removal of matrix and closure by bone pate with fibrin glue. MATERIALS AND METHODS: We evaluated 25 patients who had operatively closed labyrinthine fistulae of horizontal semicircular canal in the chronic otitis media with cholesteatoma using CT. Seven human temporal bones with labyrinthine fistulae were studied. The fistulae were closed with bone pate using fibrin glue and fascia. RESULTS: Postoperative CTs show that, in all cases, the layer closing the fistulae was indistinguishable from the surrounding bony otic capsule. CONCLUSIONS: Canal down mastoidectomy with closure of fistulae using bone pate with fascia were effective for new bone formation at the fistulae site.

The Effect of Bioresorbable Membrane on the Bone Regeneration of Streptozotocin Induced Diabetic Rats / 대한치주과학회지

The purpose of this study is to evaluate the effects of bioresorbable membranes in guided bone regeneration of streptozotocin induced diabetic rats. 50 Sprague-Dawley rats were randomly categorized into 4 groups: Group 1 & 2 had 10 normal rats each and group 3 & 4 included 15 streptozotocin induced diabetic rats each. Defect measuring 7mm in diameter was formed on every rat calvarium. No membrane was used in groups 1 & 3 and membranes were used in groups 2 & 4. The rates were sacrificed at 2 and 4 weeks after defect formation. Routine histological specimens were prepared. Masson-trichrome and HE stain were done before light microscopy. Guided regenerative potential was evaluated by measuring the amount of new bone formation in the calvarial defect by histomorphometry. Following results were obtained. 1.New bone formation in the diabetic groups was significantly less that than in the normal groups regardless of membrane use(p <0.05). 2.In the comparison of new bone formation in the normal groups, membrane group showed significantly more bone formation(p <0.1). 3.When the amount of new bone formation was compared in the diabetic groups, more bone was formed in the membrane groups but the difference was not statistically significant. 4.In the normal groups the amount of new bone formation was significantly greater at 4 weeks compared to that at 2 weeks(p <0.05) but amount of bone regeneration at 4 weeks was not significantly greater than that at 2 weeks in both diabetic groups.

Periodontal repair in dogs: effect of the modified calcium sulfate paste on the 1-wall intrabony defects / 대한치주과학회지

The purpose of this study was to evaluate the effect of modified calcium sulfate paste on periodontal regeneration. 1-wall intrabony defect(mesio-distal width: 4mm, depth: 4mm) was surgically created on the distal side of P2 and mesial side of P4 in four dogs. The control group(GFS) was treated with conventional flap operation alone, and the experimental group(CS) observations were as follows. 1. The length of the junctional epithelium was 0.41+/-0.0lmm in the control groups, 0.47+/-0.0lmm in the experimental group. 2. The connective tissue attachment was 0.28+/-0.02mm(6.15+/-0.28%) in the control group, 0.18+/-0.0lmm(3.41+/-0.14%) in the experimental group. The control group showed more connective tissue attachment. 3. The new cementum formation was 3.80+/-0.06mm(84.80+/-0.33%) in the control group, 4.49+/-0.06mm(87.57+/-0.15%) in the experimental group. Both groups showed a lot of new cementum formation. 4. The new bone formation was 1.43+/-0.03mm(32.37%) in the control group, 2.04+/-0.09%nm(40.94%) in the experiment group. 5. The inflamatory cells were observed partially around resorbed calcium sulfate in the connective tissue of the experimental group. 6. Partially resorbed calcium sulfate were found within the connective tissue, around alveolar bone, and in the newly formed alveolar bone, On the basis of these results, newly formed calcium sulfate paste enhanced new bone formation and new cementum formation. The resorption rate of calcium sulfate seems to he controlled by the add-in compounds. Thus research about biocompatibility and adequate resorptionrate is required to develop a improved material.