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.

Clinical report of cheek mass after injection and filling of hyaluronic acid in the cheek / 口腔疾病防治

Objective@#To investigate the clinical characteristics, differential diagnosis and treatment of cheek mass caused by hyaluronic acid injection. @*Methods@#From March 2014 to December 2018, data from 5 patients with cheek masses caused by cosmetic fillings admitted to the First Hospital of Shanxi Medical University were collected, and their clinical, imaging, surgical and pathological features were summarized. @*Results@#All 5 patients were young females with a history of facial hyaluronic acid filling injection. Their clinical features were buccal and facial nodular masses, all of which were treated with surgery. The pathological report was fibrous adipose tissue with fat necrosis, and chronic inflammatory cell infiltration was observed in the interstitium. After the operation, the face shape was basically symmetrical, and there were no symptoms such as infection, limited mouth opening or facial paralysis.@* Conclusion @#The injection of facial hyaluronic acid may cause complications of nodular masses in the cheek, and intraoral resection is an effective treatment with good prognosis.