Background: This study aimed to evaluate the effects of kombucha on the surface of composite resins and to examine thedegradation-inhibiting effect of adding calcium to kombucha. Methods: Six experimental groups were established, with three types of liquid kombucha: one with 3% added calcium,carbonated water as a positive control, and mineral water as a negative control. The pH and titratable acidity values of the experimental groups were measured. The samples were filled with condensed composite resin and placed in the experimental drinks for 5, 15, 30, and 60 minutes. The Vickers microhardness of the surface was measured before and after immersion, and the changes were compared. Results: The pH values of the experimental group were I’m alive (2.87±0.02), Hollys (2.95±0.01), Ediya (2.99±0.01), I’m alive +3% Ca (4.09±0.01), carbonated water (4.66±0.01), and mineral water (7.67±0.02). I’m alive (–12.35) showed the largest reduction in surface hardness, followed by Hollys (–9.78), carbonated water (–7.97), I’m alive +3% Ca (–7.82), Ediya (–7.60), and mineral water (–1.56). In the Vickers microhardness measurements, all experimental groups, except for the mineral water group, showed significant differences (p＜0.05). The scanning electron microscope results showed that the experimental group and positive control had rough surfaces and micropores. Conclusion The surface hardness was significantly reduced in all experimental groups except for water. In particular, in the caseof kombucha with low pH, the reduction rate increased, weakening the physical properties of the material. In addition, the reduction rate of surface hardness was lower in kombucha with added calcium, and it is believed that drinking kombucha containing calcium can minimize the erosion of dental materials.

Background: This study aimed to evaluate the effects of kombucha on the surface of composite resins and to examine thedegradation-inhibiting effect of adding calcium to kombucha. Methods: Six experimental groups were established, with three types of liquid kombucha: one with 3% added calcium,carbonated water as a positive control, and mineral water as a negative control. The pH and titratable acidity values of the experimental groups were measured. The samples were filled with condensed composite resin and placed in the experimental drinks for 5, 15, 30, and 60 minutes. The Vickers microhardness of the surface was measured before and after immersion, and the changes were compared. Results: The pH values of the experimental group were I’m alive (2.87±0.02), Hollys (2.95±0.01), Ediya (2.99±0.01), I’m alive +3% Ca (4.09±0.01), carbonated water (4.66±0.01), and mineral water (7.67±0.02). I’m alive (–12.35) showed the largest reduction in surface hardness, followed by Hollys (–9.78), carbonated water (–7.97), I’m alive +3% Ca (–7.82), Ediya (–7.60), and mineral water (–1.56). In the Vickers microhardness measurements, all experimental groups, except for the mineral water group, showed significant differences (p＜0.05). The scanning electron microscope results showed that the experimental group and positive control had rough surfaces and micropores. Conclusion The surface hardness was significantly reduced in all experimental groups except for water. In particular, in the caseof kombucha with low pH, the reduction rate increased, weakening the physical properties of the material. In addition, the reduction rate of surface hardness was lower in kombucha with added calcium, and it is believed that drinking kombucha containing calcium can minimize the erosion of dental materials.

Background: This study aimed to evaluate the effects of kombucha on the surface of composite resins and to examine thedegradation-inhibiting effect of adding calcium to kombucha. Methods: Six experimental groups were established, with three types of liquid kombucha: one with 3% added calcium,carbonated water as a positive control, and mineral water as a negative control. The pH and titratable acidity values of the experimental groups were measured. The samples were filled with condensed composite resin and placed in the experimental drinks for 5, 15, 30, and 60 minutes. The Vickers microhardness of the surface was measured before and after immersion, and the changes were compared. Results: The pH values of the experimental group were I’m alive (2.87±0.02), Hollys (2.95±0.01), Ediya (2.99±0.01), I’m alive +3% Ca (4.09±0.01), carbonated water (4.66±0.01), and mineral water (7.67±0.02). I’m alive (–12.35) showed the largest reduction in surface hardness, followed by Hollys (–9.78), carbonated water (–7.97), I’m alive +3% Ca (–7.82), Ediya (–7.60), and mineral water (–1.56). In the Vickers microhardness measurements, all experimental groups, except for the mineral water group, showed significant differences (p＜0.05). The scanning electron microscope results showed that the experimental group and positive control had rough surfaces and micropores. Conclusion The surface hardness was significantly reduced in all experimental groups except for water. In particular, in the caseof kombucha with low pH, the reduction rate increased, weakening the physical properties of the material. In addition, the reduction rate of surface hardness was lower in kombucha with added calcium, and it is believed that drinking kombucha containing calcium can minimize the erosion of dental materials.

Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Purpose: As the survival rate from pediatric cancers has increased significantly with advances in treatment modalities, long-term endocrine complications have also risen. This study investigated the frequencies and risks of endocrine sequelae in childhood cancer survivors who received hematopoietic stem cell transplantation (HSCT). Methods: This study included 200 pediatric patients who underwent HSCT. Clinical and endocrinological findings were collected retrospectively. The median follow-up duration after HSCT was 14 years. Results: Endocrine complications occurred in 135 patients (67.5%). Children who underwent HSCT at pubertal age (n=100) were at higher risk of endocrine complications than those who received it at prepubertal age (79% vs. 56%, P=0.001). The most common complication was hypogonadism (40%), followed by dyslipidemia (22%). Short stature and diabetes mellitus were more prevalent in the prepubertal group, whereas hypogonadism and osteoporosis were more common in the pubertal group. Being female, pubertal age at HSCT, and glucocorticoid use were predictors of an increased risk for any complication. Radiation exposure increased the risk of short stature and hypothyroidism. Hypogonadism was significantly associated with being female, pubertal age at HSCT, and high-dose radiation. Pubertal age at HSCT also increased the risks of osteoporosis and dyslipidemia. Conclusion This study demonstrates that long-term endocrine complications are common after HSCT in children and adolescents. Age at HSCT is a critical factor for endocrine complications after HSCT. These findings suggest that surveillance strategies for endocrine complications in childhood cancer survivors should be specified according to age at HSCT.

Purpose: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. Materials and Methods: From January 2001 to December 2015, data of pediatric patients (0–18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. Results: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). Conclusion The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Purpose: Data on subsequent arm lymphedema (SAL) after salvage treatment for locoregional recurrence (LRR) of breast cancer are limited. We conducted a study to evaluate the risk of SAL in patients with LRR. Methods: We reviewed the data of patients with breast cancer who had LRR and were initially diagnosed between January 2003 and December 2017. Among the 214 patients who received curative salvage treatment, most had local (n = 125, 57.9%), followed by regional (n = 73, 34.1%), and locoregional (n = 16, 7.9%) recurrences. A competing risk analysis considering the factors of death and a second LRR were performed to exclude potential malignant lymphedema. We used the Fine-Gray subdistribution hazards model to estimate the hazard ratio (HR) for comparing the risk of SAL. Results: With a median follow-up duration of 41.4 months (interquartile range, 25.6–65.1), 51 patients (23.8%) experienced SAL with a median interval of 9.9 months after treatment.The two-year cumulative incidence of SAL was 12.7%. Among the 18 patients with initial lymphedema, nine (50.0%) developed SAL. Multivariate analysis revealed that a history of lymphedema (HR, 4.61; p < 0.001) and taxane-based salvage chemotherapy (HR, 2.38; p = 0.009) were significantly associated with SAL development. Conclusion Salvage treatment for LRR-induced SAL was performed in 24% of the patients.A history of initial lymphedema and salvage taxane-based chemotherapy increases the risk of developing SAL. Therefore, close surveillance for the incidence of SAL is required in patients opting for salvage treatment for LRR.