Trueness, physical properties, and surface characteristics of additive-manufactured zirconia crown.

OBJECTIVE: This study aimed to conduct a comparison of trueness and physical and surface properties among five distinct types of additive manufactured (AM) zirconia crowns and zirconia crowns produced using the subtractive manufacturing (SM). MATERIAL AND METHODS: Zirconia crowns were fabricated using five distinct techniques, each varying in the method of slurry transfer and photocuring source. Each experimental group utilized either one of the four digital light processing (DLP)-based techniques (DLP spreading, DLP spreading gradation, DLP vat and DLP circular spreading) or the stereolithography (SLA)-based technique (SLA spreading). The control (CON) group employed SM. To assess accuracy, trueness was measured between the scan and reference data. To analyze the physical properties, voids were examined using high-energy spiral micro-computed tomography scans, and the crystal structure analysis was performed using X-ray diffraction (XRD). Surface roughness was assessed through laser scanning microscopy. RESULTS: Differences in the trueness of internal surfaces of crowns were found among the groups (P < 0.05). Trueness varied across the measurement surfaces (occlusal, lateral, and marginal) in all the groups except for the DLP spreading gradation group (P < 0.05). Voids were observed in all AM groups. All groups showed similar XRD patterns. All AM groups showed significantly greater surface roughness compared to the CON group (P < 0.001). CONCLUSION: The AM zirconia crowns showed bubbles and a rougher surface compared to the SM crowns. All groups exhibited typical zirconia traits and trueness levels within clinically acceptable limits, suggesting that current zirconia AM techniques could be suitable for dental applications.

Burst spinal cord stimulation for central neuropathic pain: Two case reports.

INTRODUCTION: Central neuropathic pain can result from any type of injury to the central nervous system. Treatment of central neuropathic pain is very challenging. Recently, a novel stimulation paradigm, called burst stimulation, has been presented as an excellent alternative in a group of patients with intractable central neuropathic pain. We report 2 cases where burst spinal cord stimulation (SCS) was applied in patients with neuropathic pain due to spinal cord injury (SCI) or traumatic brain injury. PATIENT CONCERNS: A 52-year-old man who underwent posterolateral fusion surgery for a T12 bursting fracture after a fall 11 years prior developed disabling pain in the anterolateral part of his right thigh. His neuropathic pain following SCI was refractory to various treatment modalities. A 65-year-old man had complained of intractable, cold, throbbing, and shooting pain mainly in his left lower limb during rehabilitation since undergoing a craniotomy 9 years prior for multiple brain injuries caused by a motorcycle accident. DIAGNOSIS: Both of these 2 cases were diagnosed with central neuropathic pain syndrome caused by SCI or traumatic brain injury. INTERVENTIONS: Burst SCS were proposed to alleviate the significant refractory pains that were resistant to various medications and stimulation was delivered to the patient in an alternating pattern between traditional tonic and burst waveforms. CONCLUSION: The efficacy of burst SCS in central neuropathic pain is desirable considering the severity of pain in such patients, the refractory nature of their pain, and the paucity of alternative therapeutic options.

Self-expandable metal stent of esophagogastric junction versus pyloric area obstruction in advanced gastric cancer patients: Retrospective, comparative, single-center study.

Upper gastrointestinal stenting is a palliative treatment for relieving symptoms such as nausea, vomiting, and dietary intake in patients with obstruction due to inoperable advanced stomach cancer. Self-expandable metal stent (SEMS) implantation for malignant obstruction has recently become more effective, safer, and less expensive than operative modality. It also has better short-term outcomes, particularly a shorter hospital stay and a more rapid return to oral intake, than surgical treatment. However, there is no comparative analysis regarding the efficacy, side effects, and survival rate of stenting between the esophagogastric junction (EGJ) and pyloric obstructions.To compare the prognoses and complications after SEMS implantation between EGJ and pyloric obstructions in advanced gastric cancer.Among advanced gastric cancer patients with gastrointestinal obstruction diagnosed from January 2008 to December 2017 at the Gastroenterology Department of Chungnam National University Hospital, 42 and 76 patients presented with EGJ (EGJ obstruction group) and gastric pyloric obstructions (pyloric obstruction group), respectively. We retrospectively reviewed the survival period, changes in food intake, and complications of these patients before and after SEMS placement.The prevalences of aspiration pneumonia were 11.9% (5/42) and 2.6% (2/76) in the EGJ and pyloric obstruction groups, respectively, before SEMS placement (P value: .041). Other symptoms associated with gastric malignant obstruction were not statistically different between the groups. Success rate and adverse events did not significantly differ between the EGJ and pyloric obstruction groups. There was no difference in frequency of stent reinsertion procedures performed owing to reobstruction, but the reprocedure average period was statistically significantly longer in the EGJ obstruction group [EGJ obstruction: 158.3 days (±42.4); pyloric obstruction: 86.0 days (±29.1)] (P value: .022). As an index of improved dietary status, the Gastric Outlet Obstruction Scoring System score was not significantly different between the groups before and after SEMS placement.The EGJ and pyloric obstruction groups did not significantly differ in prognosis or complication rates. However, EGJ stent was more stable than pyloric stent when reobstruction was considered.