Evaluation of fracture strength and translucency of 3D printing resin crown for carious primary anterior tooth / 대한구강보건학회지

Objectives@#The purpose of this study was to compare the fracture strength and traslucency of 3D printing resin crowns according to different thicknesses. @*Methods@#Resin crowns were designed with CAD software and a 3D scanner, using scanned data of the #61 tooth model. Resin Crowns with different thicknesses were printed using a 3D printer, and subsequently divided into four groups according to thickness (0.3, 0.5, 0.7, and 1.0 mm). Fracture strength was compared among groups with a resin strip crown of 1.0 mm thickness. Compressive force was applied using a universal testing machine at 30° along the lingual surface at 1 mm/min cross head speed. For translucency evaluation, thin square specimens were printed of thicknesses 0.3, 0.5, 0.7, and 1.0 mm, and translucency was measured using a spectrophotometer. @*Results@#As a result of fracture strength measurement, fracture strength increased as thickness increased, and a significant difference was observed solely between thicknesses of 0.3 and 0.5 mm, and the thicknesses of 0.3 and 0.5 mm (P<0.05). Translucency decreased as thickness increased, and similarly, a significant difference was observed only between thicknesses of 0.3 and 0.5 mm and the thicknesses of 0.7 and 1.0 mm (P<0.05). @*Conclusions@#A 3D printing resin crown can be used as a clinical option for restoring a primary anterior tooth affected by caries.

Similar Degree of Degeneration in the Articular and Bursal Layers of Delaminated Rotator Cuff Tear

BACKGROUND: The purpose of the study was to compare the degree of degeneration of the articular and bursal layers of delaminated supraspinatus tendons based on histological examination. METHODS: Fifty-four patients with a full-thickness rotator cuff tear were included in the study. Tendon specimens were harvested during arthroscopic rotator cuff repair from the lateral torn edges of the articular and bursal layers of the delaminated tear. Harvested samples were stained with H&E dye and evaluated based on a semi-quantitative grading scale. RESULTS: There were no significant differences in the seven histological characteristics of tendon degeneration: fiber structure, fiber arrangement, round nuclei, regional variations in cellularity, vascularity, collagen stainability, and hyalinization between the articular and bursal layers of the delaminated rotator cuff tear (all p>0.05). Total degeneration scores of articular and bursal sides were 13.1 ± 3.85 points and 13.2 ± 3.42 points, respectively, and were not significantly different (p=0.958). CONCLUSIONS: The study demonstrates that tendon degeneration was similar in the articular and bursal sides of the delaminated fullthickness rotator cuff tear, suggesting that degeneration would be a main etiology for the rotator cuff tear not only in the articular side but also in the bursal side. Considering potential disadvantages of subacromial decompression, this study tentatively suggests routine use of subacromial decompression as well as the need for halting or recovery from rotator cuff degeneration for better rotator cuff repair.

Similar Degree of Degeneration in the Articular and Bursal Layers of Delaminated Rotator Cuff Tear

BACKGROUND: The purpose of the study was to compare the degree of degeneration of the articular and bursal layers of delaminated supraspinatus tendons based on histological examination. METHODS: Fifty-four patients with a full-thickness rotator cuff tear were included in the study. Tendon specimens were harvested during arthroscopic rotator cuff repair from the lateral torn edges of the articular and bursal layers of the delaminated tear. Harvested samples were stained with H&E dye and evaluated based on a semi-quantitative grading scale. RESULTS: There were no significant differences in the seven histological characteristics of tendon degeneration: fiber structure, fiber arrangement, round nuclei, regional variations in cellularity, vascularity, collagen stainability, and hyalinization between the articular and bursal layers of the delaminated rotator cuff tear (all p>0.05). Total degeneration scores of articular and bursal sides were 13.1 ± 3.85 points and 13.2 ± 3.42 points, respectively, and were not significantly different (p=0.958). CONCLUSIONS: The study demonstrates that tendon degeneration was similar in the articular and bursal sides of the delaminated fullthickness rotator cuff tear, suggesting that degeneration would be a main etiology for the rotator cuff tear not only in the articular side but also in the bursal side. Considering potential disadvantages of subacromial decompression, this study tentatively suggests routine use of subacromial decompression as well as the need for halting or recovery from rotator cuff degeneration for better rotator cuff repair.

Prevalence and Clinical Features of Ketotic Hypoglycemia in Childhood / 대한소아내분비학회지

PURPOSE:Idiopathic ketotic hypoglycemia (IKH) is an important cause of hypoglycemia in children. The purpose of this study was to determine the prevalence of ketotic hypoglycemia and to describe the clinical manifestation. METHODS:We conducted a retrospective chart review of children presenting hypoglycemia to the emergency department (ED) of Ewha Womans University Hospital between January 1995 and June 2004. Information recorded for subject included age, gender, weight, time of presentation, presenting symptoms, and laboratory data. RESULTS:Eighty two children were identified for hypoglycemia during the study period. IKH was the ultimate diagnosis for 66 patients (80.5%). Other diagnoses included hyperinsulinism (2.4%), drug adverse event (1.2%), sepsis (1.2%), and other disorder. The mean age for presentation of IKH was 37.9+/-18.6 months. Thirty eight boys and twenty eight girls were identified. The median time of presentation was 9:48 a.m. Of the 66 subjects, body weight of 46.9% patients was below 25th percentile for age. The average blood glucose was 41.4+/-14.2 mg/dL. Symptoms at presentation included lethargy (24.2%), mental change (16.7%) and vomiting (16.7%). 49 patients (74.2%) were described as having a concomitant illness. CONCLUSION: IKH was responsible for 80.4% of cases of hypoglycemia in pediatric ED and it had usually concomitant intercurrent illness which resulting in poor oral intake. Awareness of IKH, and its presenting characteristics, will be helpful in the ED when taking care of hypoglycemic children.