Comparison of Flexural Strength of Three-Dimensional Printed Three-Unit Provisional Fixed Dental Prostheses according to Build Directions

PURPOSE: The aim of this study was to compare the flexural strength of provisional fixed dental prostheses which was three-dimensional (3D) printed by several build directions. MATERIALS AND METHODS: A metal jig with two abutment teeth and pontic space in the middle was fabricated. This jig was scanned with a desktop scanner and provisional restoration was designed on dental computer-aided design program. On the preprocessing software, the build angles of the restorations were arranged at 0°, 30°, 45°, 60°, and 90° and support was added and resultant structure was sliced to a thickness of 100 µm. Processed restorations were printed with digital light processing type 3D printer using poly methyl meta acrylate-based resin. After washing and post-curing, compressive loading was applied at a speed of 1 mm/min on a metal jig fixed to a universal testing machine. The maximum pressure at which fracture occurred was measured. For the statistical analysis, build direction was set as the independent variable and fracture strength as the dependent variable. One-way analysis of variance and Tukey's post hoc analysis was conducted to compare fracture strength among groups (α=0.05). RESULT: The mean flexural strength of provisional restoration 3D printed with the build direction of 0° was 1,053±168 N; it was 1,183±188 N at 30°, 1,178±81 N at 45°, 1,166±133 N at 60°, and 949±170 N at 90°. The group with a build direction of 90° showed significantly lower flexural strength than other groups (P<0.05). The flexural strength was significantly higher when the build direction was 30° than when it was 90° (P<0.01). CONCLUSION: Among the build directions 0°, 30°, 45°, 60°, and 90° set for 3D printing of fixed dental prosthesis, an orientation of 30° is recommended as an effective build direction for 3D printing.

Flexural strength of various kinds of the resin bridges fabricated with 3D printing

PURPOSE: Manufacturing with AM (Additive manufacturing) technique has many advantages; but, due to insufficient study in the area, it is not being widely used in the general clinic. In this study, differences of flexural strength among various materials of 3 unit fixed dental prosthesis were analyzed. MATERIALS AND METHODS: A metal jig for specimens that had a 3-unit-fixed dental prosthesis figure were fabricated. The jigs were made appropriately to the specifications of the specimens. Three different kinds of materials of specimens which were NC (mathacrylic esther based), DP-1 (Bisphenol A epoxy acrylate type oligomer based), and DT-1 (urethane acrylate based) were printed with DLP machine. Five specimens for each kind of material were printed with an angle of 30° from the horizontal surface. The specimens were placed on the jig and the flexural strength was measured and recorded using Universal testing machine. The recorded data was analyzed in SPSS using One-way ANOVA and Tukey HSD to determine the significance of the differences of flexural strength among the groups. RESULTS: The flexural strengths of each group were the followings: NC, 1119 ± 305 N; DP-1, 619 ± 150 N; DT-1, 413 ± 65 N. Using One-way ANOVA and Tukey Honestly Significant Difference test, significant difference was found between NC and the other groups (P 0.05). CONCLUSION: Higher flexural strength was shown in 3-unit-fixed dental prosthesis that were 3D printed using a DLP machine with NC material.

Cervical Endometriosis in a Post-menopausal Woman: A Case Report / 대한폐경학회지

Cervical endometriosis is defined as the presence of endometrial glands and stroma at the cervix. This is rare and sometimes asymptomatic. Most of these are diagnosed by incidental findings within histopathology. As the presence of cytological features do not guarantee the presence of cervical endometriosis, it is difficult to diagnose this disorder prior to surgery. We recently encountered a case of cervical endometriosis in a post-menopausal woman who was not receiving hormone therapy. As a reminder to clinicians about this neglected issue, we report a case of cervical endometriosis with a literature review.

Diagnostic Accuracy of Cervicovaginal Cytology in the Detection of Squamous Epithelial Lesions of the Uterine Cervix; Cytologic/Histologic Correlation of 481 Cases / 대한세포병리학회지

BACKGROUND: Cervicovaginal cytology is a screening test of uterine cervical cancer. The sensitivity of cervicovaginal cytology is less than 50%, but studies of cytologic/histologic correlation are limited. We analyzed the diagnostic accuracy of cervicovaginal cytology in the detection of the squamous epithelial lesions of the uterine cervix and investigate the cause of diagnostic discordance. MATERIALS AND METHODS: We collected a total of 481 sets of cervicovaginal cytology and biopsies over 5 years. The cytologic diagnoses were categorized based on The Bethesda System and the histologic diagnoses were classified as negative, flat condyloma, cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, or squamous cell carcinoma. Cytohistologic discrepancies were reviewed. RESULTS: The concordance rate between the cytological and the histological diagnosis was 79.0%. The sensitivity and specificity of cervicovaginal cytology were 80.6% and 92.6%, respectively. Its positive predictive value and negative predictive value were 93.7% and 77.7%, respectively. The false negative rate was 19.4%. Among 54 false negative cytology cases, they were confirmed by histology as 50 flat condylomas, 2 CIN I, 1 CIN III, and 1 squamous cell carcinoma. The causes of false negative cytology were sampling errors in 75.6% and interpretation errors in 24.4%. The false positive rate was 7.4%. Among 15 false positive cytology cases, they were confirmed by histology as 12 atypical squamous cells of undetermined significance (ASCUS) and 3 low grade squamous intraepithelial lesions (LSIL). The cause of error was interpretation error in all cases. The overall diagnostic accuracy of cervicovaginal cytology was 85.7%. CONCLUSIONS: Cervicovaginal cytology shows high overall diagnostic accuracy and is a useful primary screen of uterine cervical cancer.

Xanthogranulomatous Pyelonephritis with Spontaneous Nephrocutaneous Fistula / 대한비뇨기과학회지

Fistula formation between the upper urinary tract and cutaneous tissue is an uncommon complication in urogenital disease. Xanthogranulomatous pyelonephritis(XGP) is a severe, chronic infection of the renal parenchyma that is often associated with calculi and obstruction. We present a rare case of XGP with a nephrocutaneous fistula.

A Case of Double Primary Neurilemmoma on Both Chest Wall, One of Them is Bulging to Skin from Intercostal Nerve / 결핵및호흡기질환

Neurilemmomas are benign nerve sheath tumors derived from Schwann cells that rarely occur in the chest wall. Neurilemmomas of the chest wall are usually solitary lesions that bulge toward the pleural cavity. Neurilemmomas are confirmed histologically based on the presence of Verocay bodies, Antoni A and Antoni B tissue patterns and S-100 protein. Bilateral neurilemmomas in the chest wall are extremely rare, as are those that grow in the subcutaneous tissue but not the pleural area. We report here a case of bilateral chest wall neurilemmomas in which the tumors bulged out to the skin and were palpable.

A Case of Eccrine Porocarcinoma on Back

PURPOSE: Eccrine porocarcinoma is a very rare, potentially fatal tumor which arises from the intraepidermal portion of the eccrine sweat ductal apparatus. It does not have a characteristic clinical feature but does have a high incidence of metastasis. It may be developed de novo or in a preexisting benign eccrine poroma. It usually affects older people and is located most commonly on lower extremities. We report a rare case of eccrine porocarcinoma which developed on the back without metastasis. METHODS: The patient was a 94-year-old woman who showed a painful, ulcerated, dark brown colored polypoid 3.5x3.0cm sized mass on the back for 3 years. We totally excised the lesion including normal tissue. RESULTS: After wide excision of the lesion, pathologist reported an eccrine porocarcinoma. Histopathologic findings reveal that the classic type of eccrine gland carcinoma, eccrine porocarcinoma. Immunocytochemical studies showed a positive reactivity to anti-EMA antibody and anti-CEA antibody. CONCLUSION: Authors experienced a rare case of primary eccrine porocarcinoma on the back. Because of the propensity to develop local recurrence, wide excision of the primary tumor with histologic confirmation of negative margins represents the only curative treatment regimen for eccrine porocarcinoma.

A Case of Gastric Inverted Hyperplastic Polyp Associated with Gastritis Cystica Profunda and Early Gastric Carcinoma

A gastric inverted hyperplastic polyp is characterized by downward growth of the hyperplastic mucosal components into the submucosa. Lesions are composed of hyperplastic foveolar-type glands, and sometimes coexist with gastritis cystica profunda (GCP). Adenocarcinoma frequen- tly can coexist, but the relationship is not clear. A 71-year-old male was admitted to hospital because of dyspepsia for one month. He underwent a wedge resection of the stomach, after endoscopic biopsies. The gross finding showed a slightly elevated papillary lesion with central depression. Microscopically, the elevated lesion was composed of hyperplastic fundic glands and foveolar cells, and the central depressed lesion showed a nodular inverted proliferation of normal appearing gastric epithelium and glands in the submucosa. An additional proximal gastrectomy specimen exhibited marked GCP and a minute adenocarcinoma at the proximal margin with p53 protein overexpression.

A Sertoli-Leydig Cell Tumor in a Patient with Complete Androgen Insensitivity Syndrome: A Case Report

Complete androgen insensitivity syndrome (CAIS) is a rare disorder sometimes referred to as male pseudohermaphroditism. This syndrome is characterized by a 46,XY karyotype with internal bilateral testes, female external genitalia, absence or scantiness of pubic and axillary hair and normal breast development. A variety of gonadal tumors can develop in individuals with CAIS. A 57-year-old patient was admitted to urology with intermittent gross hematuria for one month. CT revealed a left ureteric mass, measuring 2.5 x 2 cm. Ureteroscopic biopsy was performed and the result was a diagnosis of high grade urothelial carcinoma. The patient underwent laparotomy which revealed slightly enlarged gonads in the pelvic cavity. However, a uterus and fallopian tubes were not identified. Left nephroureterectomy and bilateral gonadectomy were performed. The right gonad measured 3.9 x 2.5 x 2 cm and the cut surface showed a well circumscribed, firm, brownish gray colored 2 x 1.8 cm sized nodule. Microscopically, this nodule consisted of uniform and solid tubules containing immature Sertoli cells and Leydig cells which were both positive for alpha-inhibin. The left gonad measured 3.5 x 2 x 1.9 cm and showed atrophic testicular tissue.

Endoscopic Ligation Therapy for Gastric Angiodysplasia / 대한소화기내시경학회지

Gastric angiodysplasia may be responsible for up to 2% to 6% of upper gastrointestinal bleeding. Moreover, gastric angiodysplasia may be particularly difficult to treat and is usually associated with a high rebleeding rate. Bleeding due to gastric angiodypsplasia is usually treated by various endoscopic approaches, including argon and Nd:YAG laser photocoagulation, monopolar or biopolar electrocoagulation, heater probe, or injection. Associated complications of these methods, however, such as perforation, acute bleeding during the procedure, or delayed massive hemorrhage have been reported. Recently a few reports have been suggested that endoscopic ligation therapy is a safe, effective treatment for gastric angiodysplasia. A 70-year-old man, who had undergone subtotal gastrectomy for perforation of a duodenal ulcer for 20 years, was admitted due to melena and dizziness persisting for 1 week. A gastroscopy revealed a single angiodysplasia with active bleeding just above the anastomotic site of the remnant stomach. Endoscopic ligation therapy was performed successfully and the bleeding stopped immediately after endoscopic ligation. Since then, no recurrence of bleeding has been reported to date.

A Case of Meckel's Enterolith / 대한소화기내시경학회지

The term enterolith refers to concretions formed within the gastrointestinal tract. Enteroliths are thought to result from stasis and are usually found proximal to an area of stricture or within diverticulum. Meckel's diverticulum occurs in 1% to 3% of the population at autopsy and is the most common congenital anomaly of the gastrointestinal tract. Common complications of Meckel's diverticulum include hemorrhage, infection, inflammation, and intussusception. However, enterolith formation in a Meckel's diverticulum, which referred to as Meckel's enterolith, is rare. A 58-year-old female who experienced constipation and low abdominal pain for 20 years, was admitted due to severe low abdominal pain for 3 days. A 3 2 cm sized, lozenge-shaped radiopaque stone with peripheral dense calcification and radiolucent center, located between two areas of stricture in the distal ileum, was observed in abdominal radiograph, abdominal sonogram, small bowel study, and CT scan. Pathologic findings after surgery reveal an enterolith in Meckel's diverticulum without ectopic gastric mucosa. The case of Meckel's enterolith is herein reported.

A Case of Hydrogen Peroxide Induced Colitis / 대한소화기내시경학회지

Hydrogen peroxide has been used for various medical purposes and also recommended in the disinfection process for endoscopes. However, hydrogen peroxide as a cause of chemical colitis or disinfectant colitis has been infrequently reported. The endoscopic findings of hydrogen peroxide induced colitis revealed pseudomembranous-like enteritis such as white plaques, erythema, foamy liquid, patchy, granularity, and ulcerations, resulting from effervescence caused by the release of oxygen from the breakdown of hydrogen peroxide. A 36 year-old single male, who had 30 ml of 3% hydrogen peroxide inserted into his anus the day before due to sexual reasons, was hospitalized as a result of suffering from hematochezia, tenesmus, and lower abdominal pain. Colonoscopy revealed discrete or confluent white plaques adherent to the colonic mucosa, severe erythema on the surrounding mucosa, patchy granularity, and scattered ulcerations up to 28 cm from the anal verge. Pathologic finding revealed inflammatory cells infiltration, variable sized vacuoles, vascular congestion, hemorrhage, fibrin deposition and ulcerations with regenerating epithelium in the lamina propria, consistent with acute mucosal injury caused by hydrogen peroxide. A case of hydrogen peroxide induced colitis is herein reported.

A Case of Spindle Cell Carcinoma of the Esophagus / 대한소화기내시경학회지

Spindle cell carcinoma of the esophagus containing both carcinomatous and sarcomatous elements is rare, accounting for approximately 1- 2% of all esophageal neoplasms. Terms used to describe this lesion include carcinosarcoma, pseudosarcoma, polypoid carcinoma, pseudosarcomatous squamous cell carcinoma and spindle cell variant of squamous cell carcinoma. Spindle cell carcinomas were originally classified as carcinosarcomas or pseu- dosarcomas, depending on the morphology and bilologic behavior of the particular lesian. However, pseudosarcoma and carcinosarcoma appear to be the same pathologic entity with varying degrees of anaplastic spindle cell metaplasia of the carcinomatous portion of the tumor. Thus, these lesions have been clsssified together as spindle cell carcinomas. A 59 year-old man who experienced weight loss for 4 months was hospitalized as a result of suffering from dysphagia for 2 months. A diffuse bulky protruding mass with superficial ulceration and easy friability on 25 to 35 cm from the incisors, which invaded the right intermediate bronchus and involved the right paratracheal and subcarnial lymph nodes, were obsetved in esophagogram, endoscopy and chest CT. Pathologic finding, including immunoreactivity to cytokeratin and vimentin, was consistent with spindle cell carcinoma. We report a case of spindle cell carcinoma of the esophagus.

A Case of Gastric Anisakiasis Causing Mallory - Weiss Syndrome / 대한소화기내시경학회지

Anisakiasis is an infection in humans caused by larval nematodes of the family Anisakidae and is encountered in people who eat inadequately prepared raw, salt-water fish or "sashimi". This clinical syndrome is characterized by severe cramping abdominal pain, nausea, and vomiting. Because Koreans like to eat raw fish, anisakiasis of the stomach has been reported occasionally, but the incidences of upper gastrointestinal bleeding caused by anisakiasis has been very rare. The present case is a 30 year-old male Admitted with an episode of hematemesis. A gastrofibroscopy revealed a mucosal laceration and the larva of Anisakis on the esophagogastric junction. We report one case of Mallory-Weiss Syndrome due to gastric Anisakis larva, confirmed by an endoscopy.