Finite element analysis of the effects of periodontal tissue temperature by continuous wave technique / 华西口腔医学杂志

OBJECTIVES@#The safety of root canal filling with 200 °C hot gutta-percha was investigated to study the effect of continuous wave technique combined with high-temperature injectable gutta-percha condensation technique on the surface temperature of periodontal tissue.@*METHODS@#CT technique and Mimics, Geomagic, and Solidworks software were utilized to build the entity models of alveolar bone, dentin and root canal, periodontal ligament, and blood flow, respectively, which were then assembled in Solidworks into a finite element model of tooth with blood flow. By utilizing ABAQUS collaborative simulation platform, fluid-structure coupling was analyzed on the whole process of root canal filling. Consequently, the surface temperature of the periodontal tissue was obtained.@*RESULTS@#In the absence of blood flow, the temperature of the periodontal ligament surface reached 50.048 ℃ during root canal filling with 200 ℃ gutta-percha. Considering blood flow, the temperature of periodontal ligament surface was 39.570 ℃.@*CONCLUSIONS@#The temperature of the periodontal ligament surface increased when the continuous wave root canal was filled with 200 ℃ gutta-percha, and the periodontal tissue was not damaged.

The value of endoscopic ultrasonography on diagnosis and treatment of esophageal hamartoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To examine the values of endoscopic ultrasonography (EUS) on diagnosis and treatment of esophageal hamartoma.</p><p><b>METHODS</b>We compared and analyzed various kinds of imaging examinations such as barium esophagram, contrast-enhanced computed tomography (CT) and conventional gastroscopy in retrospectively reviewing the clinical data of an esophageal hamartoma patient seen in our clinic in the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China. Having received various imaging examinations, this patient was finally diagnosed with esophageal hamartoma and underwent gastroscopic resection of hamartoma with the diagnostic information obtained from EUS. The patient had been regularly followed up for 13 months after treatment.</p><p><b>RESULTS</b>Barium esophagram, CT and conventional gastroscopy detected the lesion, but were unable to distinguish it from common esophagopolypus and other submucosal lesions, and unable to determine etiopathogenisis. EUS detected the hamartoma and identified its internal structure, echo, exact size, depth of invasion, origin and the relationship between adjacent tissues and organs, differentiating the lesion from other submucosal tumors and clearly defining the diagnosis. EUS-guided fine needle aspiration (FNA) also helped to identify the etiological diagnosis.</p><p><b>CONCLUSION</b>EUS was superior to other imaging means in diagnosis and treatment of hamartoma.</p>