The machining accuracy of zirconia prostheses fabricated by the subtractive (SM) and additive manufacturing (AM) was evaluated using the Merlon fracture test model in ISO 18675 (2022). The SM specimens were fabricated by a DWX-51D (Roland, Sydney, NSW, Australia) using two zirconia blocks (Katana Zirconia HT; KH, Katana Zirconia STML; KS). The AM specimens were prepared by a DLP type 3D printer INNI-Ⅱ (AON, Gunpo, Korea) using zirconia liquid slurry (INNI-CERA; PZ). The specimen STL image was acquired using a model scanner (E3, 3 Shape A/S, Copenhagen, Denmark). The machining accuracy of the specimens was analyzed by the RMS method superimposing the reference STL image and the specimen STL image in image analysis software (Geomagic Control X, 3D Systems, Rock Hill, SC, USA). From the results of the machining accuracy analysis, the KH and KS groups showed statistically significantly better machining accuracy (lower RMS) than the PZ group (P<0.05). The KH and KS groups showed higher machining accuracy as the thickness decreased, and the 0.2 mm and 0.3 mm experimental groups showed statistically significantly better machining accuracy than the 0.4 mm experimental group (P<0.05). On the other hand, the PZ group showed better machining accuracy as the thickness increased, with the 0.4 mm group showing statistically significantly better machining accuracy than the 0.2 mm and 0.3 mm groups (P<0.05). Within the limitation of this study, the thickness of the final zirconia prosthesis fabricated by additive manufacturing should be at least 0.4 mm for clinical use in dentistry.

Background/Aims: Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication. Methods: Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years). Results: All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57). Conclusions The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Background/Aims: Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication. Methods: Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years). Results: All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57). Conclusions The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Background/Aims: Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication. Methods: Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years). Results: All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57). Conclusions The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Background/Aims: Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H.pylori eradication. Methods: Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50–59 years), group 3 (60–69years), and group 4 (≥70 years). Results: All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12).After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57). Conclusions The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Background: Assessing and improving the quality of trauma care is crucial in modern trauma systems and centers. In Korea, evaluations of regional trauma centers are conducted annually to assess and improve trauma management quality. This includes using the Trauma and Injury Severity Score (TRISS) method to calculate the W-score and mortality Observed-to-Expected ratio (O:E ratio), which are used to evaluate the quality of care. We analyzed the potential for overestimation of the probability of survival using TRISS method for patients with neurotrauma, as well as the potential for errors when evaluating and comparing regional trauma centers. Methods: We included patients who visited the regional trauma center between 2019 and 2021 and compared their probability of survival of the TRISS method, W-score, mortality O:E ratio, and misclassification rates. The patient groups were further subdivided into smaller subgroups based on age, Glasgow Coma Scale (GCS), and Injury Severity Score, and comparisons were made between the neurotrauma and non-neurotrauma groups within each subgroup. Results: A total of 4,045 patients were enrolled in the study, with 1,639 of them having neurotrauma. The neurotrauma patient group had a W-score of −0.68 and a mortality O:E ratio of 1.044. The misclassification rate was found to be 13.3%, and patients with a GCS of 8 or less had a higher misclassification rate of 37.4%. Conclusion The limitations of using the TRISS method for predicting outcomes in patients with severe neurotrauma are exposed in this study. The TRISS methodology demonstrated a high misclassification rate of approximately 40% in subgroups of patients with GCS less than 9, indicating that it may be less reliable in predicting outcomes for severely injured patients with low GCS. Clinicians and researchers should be cautious when using the TRISS method and consider alternative methods to evaluate patient outcomes and compare the quality of care provided by different trauma centers.

BACKGROUND: In guided bone regeneration (GBR), there are various problems that occur in the bone defect after the wound healing period. This study aimed to investigate the enhancement of the osteogenic ability of the dual scaffold complex and identify the appropriate concentration of growth factors (GF) for new bone formation based on the novel GBR concept that is applying rapid bone forming GFs to the membrane outside of the bone defect. METHODS: Four bone defects with a diameter of 8 mm were formed in the calvaria of New Zealand white rabbits each to perform GBR. Collagen membrane and biphasic calcium phosphate (BCP) were applied to the bone defects with the four different concetration of BMP-2 or FGF-2. After 2, 4, and 8 weeks of healing, histological, histomorphometric, and immunohistochemical analyses were conducted. RESULTS: In the histological analysis, continuous forms of new bones were observed in the upper part of bone defect in the experimental groups, whereas no continuous forms were observed in the control group. In the histomorphometry, The group to which BMP-2 0.5 mg/ml and FGF-2 1.0 mg/ml was applied showed statistically significantly higher new bone formation. Also, the new bone formation according to the healing period was statistically significantly higher at 8 weeks than at 2, 4 weeks. CONCLUSION The novel GBR method in which BMP-2, newly proposed in this study, is applied to the membrane is effective for bone regeneration. In addition, the dual scaffold complex is quantitatively and qualitatively advantageous for bone regeneration and bone maintenance over time.

Objective: The Rotterdam scoring system (RSS) is useful for prognosis prediction in patients with severe traumatic brain injury (sTBI). It comprises basal cistern, midline shifting (MLS), epidural hematoma (EDH), and subarachnoid hemorrhage (SAH)/intraventricular hemorrhage (IVH) status. Brain computed tomography (CT) is important to assessing patients with sTBI; however, results often change over time. We aimed to determine whether RSS outcome prediction differs by initial brain CT scan time after the trauma in patients with sTBI. Methods: We used data from the second Korea Neurotrauma Data Bank, and analyzed 455 patients; RSS, Glasgow Outcome Scale Extended (GOSE) on 6-months, and the CT scan time were obtained. Unfavorable outcomes were defined as a GOSE score of 1–4. Participants were divided into 2 groups according to when brain CT scan was performed (> or ≤ 2 hours after trauma). The relationship between the prognosis of patients with sTBI and RSS score was examined by calculating the odds ratios. Univariate and multivariate analyses were performed. Results: In both univariate and multivariate analysis, the total RSS and basal cistern status were statistically correlated with prognosis in both groups. EDH and SAH/IVH showed statistically significant difference according to CT scan time. MLS was associated with prognosis in both groups in univariate analysis although not in multivariate analysis. Conclusion The total RSS score predicted prognosis 6 months after trauma in patients with sTBI, regardless of CT scan time. However, the prognostic predictive power of each item constituting the RSS varied according to CT scan time.