STATEMENT OF PROBLEM: Many kinds of post and core systems are in the market, but there are no clear selection criteria for them. PURPOSE: The purpose of this study was to compare the flexural strength and modulus of elasticity of core materials, and measure the bending strength of post systems made of a variety of materials. MATERIAL AND METHODS: The flexural strength and elastic modulus of thirteen kinds core buildup materials were measured on beams of specimens of 2.0 x 2.0 x 24 +/- 0.1mm. Ten specimens per group were fabricated and loaded on an Instron testing machine at a crosshead speed of 0.25mm/min. A test span of 20 mm was used. The failure loads were recorded and flexural strength calculated with the measured dimensions. The elastic modulus was calculated from the slopes of the linear portions of the stress-strain graphs. Also nine kinds commercially available prefabricated posts made of various materials with similar nominal diameters, approximately 1.25mm, were loaded in a three-point bend test until plastic deformation or failure occurred. Ten posts per group were tested and the obtained data were anaylzed with analysis of variance and compared with the Tukey multiple comparison tests. RESULTS: Clearfil Photo Core and Luxacore had flexural strengths approaching amalgam, but its modulus of elasticity was only about 15% of that of amalgam. The strengths of the glass ionomer and resin modified glass ionomer were very low. The heat pressed glass ceramic core had a high elastic modulus but a relatively low flexural strength approximating that of the lower strength composite resin core materials. The stainless steel, zirconia and carbon fiber post exhibited high bending strengths. The glass fiber posts displayed strengths that were approximately half of the higher strength posts. CONCLUSION: When moderate amounts of coronal tooth structure are to be replaced by a post and core on an anterior tooth, a prefabricated post and high strength, high elastic modulus core may be suitable.
Carbon ; Ceramics ; Elastic Modulus ; Glass ; Hot Temperature ; Patient Selection ; Plastics ; Stainless Steel ; Tooth

Approximately 15% of all fractures in children involve the physis. Although the majority heal without impairment of the growth mechanism, epiphyseal growth plate fracture-seperation can lead to shortening and angulation. The physiologic events in epiphyseal growth fracture seperation that lead to growth disorders relate to 1) destruction of the epiphyseal circulation and 2) communication between the epiphyseal circulation with its osteoprogenitor cells, thus forming a bony bridge. Although the classic procedure of osreotomy, epitphysiodesis, leg shortening and leg lengthening have not lost their importance in the treatment of the sequeales of partial closure of an epiphyseal plate, the possibility of regaining growth in the affected region should be considered before other measures are taken. Simple excision of the bone bridge is ineffective, since the large cancellous surface thus produced will allow for rapid reformation of the bridge. Thus, a material has to be interposed into the defect created by removal of such a bridge in order to prevent its reformation. Langenskiold first demonstrated that a bone bridge could be effectively resected and its reformation prevented by utilizing fat as an interposition material. Other investigators have used a variety of different interposition materials to prevent bone bridge recurrence following operative removal including cartilage, Silastic, Methymethacrylate, bone wax, muscle flap, Gelfoam as well as fat. Thus it is the purpose of this study to analysis and comparing shortening and angulation by resection of a bone bridge and its replacement with different interposition materials. For this study, a total of 32 rabbits with an initial weight of about 600 to 800 gm was used. Control group comprised 4 rabbits and after appmpriate preparation, the medial condyle of the pmximal tibia was exposed surgically. One plug of bone was removed at the level of the epiphyseal plate using a small curet to a depth of 5 mm. and in the other groups, we made a defect with the same curet and filled it with an interposition material directly. The following experimental groups were created. Group 1 (N-4) Control group: no interposition material Group 2 (N-4) Gelfoam interposition material Group 3 (N-4) Bone was interposition material Group 4 (N-4) Muscle flap interposition material Group 5 (N-4) Fat interposition material Group 6 (N-4) Bone cement interposition material Group 7 (N-4) Silastic interposition material Postoperatively the anirnals were sacrificed 15wks following operation. As sacrifice, tibia including fibular is removed, examined grossly and radiographed. Tibia length and angular deformity were determined by measurement of radiographs. Specimens stained with H-E stain were observed during 15 wks after operation. Through these examination, following results were obtained. l. In control group, coronal histological sections of each curetted proxirnal tibial growth plate revealed osseous bridging as early as 3 wks, and this bridging was found consistently in all control groups for the duration of the study. 2. The groups using gel foam, muscle flap and bone wax as interposition material were found effective for the prevention of the formation of epiphyseometaphyseal bone bridge to some extent. 3. The groups using Silastic or bone cement diminished both the angular deformity and growth retradation to a highly significant degree. Although the use of fat did reduce somewhat the amount of shortening and angular deformity when used as an interposition material, it was not effective as Silastic or bone cement. 4. Coronal histological section of the traumatized, margin of the growth plate, with an interposition material revealed thin fibrous layer and lose columnar orientation, foam rounded clone-like structures and randomness to growth. The injured portion of the cartilage may originate from the regeneration of the adjacent part of the growth plate. From these morphological and radiological results, it is suggested that Silastic or bone cement is better interposition material in the elimination of trahsphyseal closure after physeal damage.
Cartilage ; Child ; Congenital Abnormalities ; Gelatin Sponge, Absorbable ; Growth Disorders ; Growth Plate ; Humans ; Leg ; Rabbits ; Recurrence ; Regeneration ; Research Personnel ; Tibia

The incidental observation of periosteal new bone formation on long bones is common in pediatric radiology without any symptoms in extremities : for example, the humeri on chest examination and the femora on abdominal roentgenograms. The purposes of the author is to report the results of a roentgenologic study of the long bones in 100 normal infants and 100 chilren between 1 and 2 years old who had no symptoms refereble to the skeleton to determine the incidence, roentgen characteristics, pathogenesis and significance of this type of periosteal new bone. The results obtained were as follows : 1. Periosteal new bone occured in 28% in normal infants group but did not occured in children group between 1 and 2 years. 2. The site in order of decreasing frequency were femur, tibia, and humerus. 3. Periosteal new bone is always on the diaphysis and usually extended onto the metaphysis to a variable extent, but it has not been observed to reach the end of metaphysis. 4. It seems most logical that the periosteal new bone found in these infants is simply a roentgen manifestation of normal periosteal bone growth in the period of greatest activity. 5. It is not an indication for treatment unless a definite relationship with a specific disease is proven.
Bone Development ; Child ; Diaphyses ; Extremities ; Femur ; Humans ; Humerus ; Incidence ; Infant ; Logic ; Osteogenesis ; Skeleton ; Thorax ; Tibia

We Report a hibernoma which ocurred in a 30-year-old male, who had 2cm sized, well-marginated, subcutaneous mass on the right side of the scapula. Histopathologic finding showed the tumor was composed of uniform granular or multivacuolated, eosinophilic, round to ovoid cells with small and peripherally plnced nuclei. Total exrision of the tumor was performed. No recurrence was observed for 5 months after surgical excision.
Adult ; Eosinophils ; Humans ; Lipoma* ; Male ; Recurrence ; Scapula

No abstract available.
Muscular Atrophy*

The antihypertensive effects of once-daily 15mg dose of tripamide(Normonal(R)) were observed in 30 cases of essential hypertension, and the results were as follows; 1) Mean drop in systolic and diastolic pressure were 30 mmHg and 16 mmHg, respectively. 2) In 76.7% of cases, good or fair control of blood pressure was resulted. 3) There was no significant difference in heart rate before and after treatment. 4) There was no significant difference in serum K, BUN, and FBS before and after treatment. 5) There was no any other side effect which required discontinuing the treatment.
Blood Pressure ; Heart Rate ; Hypertension

No abstract available.
Immunosuppression*

1. Two hundred and fifty cases of fractures of the tibia treated at the orthopedic department of the Catholic Medical College during period of January, 1966 to September, 1971 were subjected to analysis. 2. The evaluation was done according to the classification of Ellis. Among 250 cases of the tibial fractures 120 being mild grade, 63 moderate grade and 67 severe grade. 3. Of 6 groups, 1st group was treated with toe to groin cast, 2nd group was treated with functional below the knee cast, 3rd group was treated with pin & plaster, 4th group was treated with 1–2 screw fixation & wiring, 5th group was treated with plate fixation and 6th group was treated with intramedullary nailing. 4. The healing time is almost proportional to the severity of the fracture grade and also the better prognosis largely depends on the mild grade. 5. We experienced 9 cases of non-union (3.6%), 19 cases of delayed union (7.6%) in most of moderate and severe grade.
Classification ; Fracture Fixation, Intramedullary ; Groin ; Knee ; Orthopedics ; Prognosis ; Tibia ; Tibial Fractures ; Toes

Blunt trauma severe enough to cause fracture of the long bones of the lower extremity may seriously damage adjacent arteries either by direct or indirect force. Diagnosis of disruption or thrombosis by this combination of injuries, is frequently delayed until the opportunity to salvage the extremity is lost. This error will result in an excessively high amputation rate. From September 1971 to August 1972, six Cases with or without fracture were treated at the Orthopedic Department of the Catholic Medical College. Of these six, three resulted in amputation by losing the chance to make the early diagnosis of injury.
Amputation ; Arteries ; Diagnosis ; Early Diagnosis ; Extremities ; Lower Extremity ; Orthopedics ; Thrombosis ; Vascular System Injuries

We report a pigmented follicular cyst (PFC) in a 40-year-old male manifestated clinically as pigmented nevus. Histopathologic findings revealed an infundibular cyst in the mid dermis containing a small amount of keratinous material. The cystic wall consisted of four or five layers of squamous epithelium with a granular layer with abundant keratohyaline granules and the cyst wall contained one hair follicle. It must be differentiated from other pigmented lesions of over-lying skin such as eruptive vellus hair cyst, apocrine hydrocystoma and melanocytic nevus coexistance of an epidermoid cyst. Surgical excision and histopathological examination are necessary for an accurate diagnosis in pigmented lesions.
Adult ; Dermis ; Diagnosis ; Epidermal Cyst ; Epithelium ; Follicular Cyst* ; Hair ; Hair Follicle ; Humans ; Male ; Nevus, Pigmented ; Skin