Three-dimensional finite element stress analysis of surface-mounted inlays in repairing pulp-penetrating non-carious cervical lesion of maxillary first premolar / 华西口腔医学杂志

OBJECTIVES@#This study aimed to explore the stress distribution of surface-mounted inlays with two ceramic materials and different strategies for fiber post-restoration on pulp-penetrating non-carious cervical lesion in a maxillary first premolar to provide minimally invasive and reasonable restorative methods.@*METHODS@#The cone beam computed tomography data of the standard right upper first premolar were selected. Healthy control (HC) and defective control (DC) finite element models were established. Then, eight experimental models were established according to two different ceramic materials (IPS e.max CAD [LD] and Lava Ultimate [LU]) and different locations of fiber post (without fiber post [NP], fiber post in buccal root canal [B], fiber post in palatal root canal [P], fiber post in both root canals [BP]), namely, LDNP, LDB, LDP, LDBP, LUNP, LUB, LUP, and LUBP. Axial load F1 and lateral load F2 were applied. Maximum principal stress and displacement of the buccal tip were investigated using finite element analysis software. Then, the percentage change of the following indicators in each experimental group was analyzed: stress of defective tip with group DC, stress of enamel and dentine, and displacement of buccal tips with group HC. It was considered similar when the percentage change was less than 5%.@*RESULTS@#LD and LU groups could effectively reduce the stress of the defective tip, but the decreasing amplitude in the former was greater than that of the latter. For the stress of surface-mounted inlays and resin adhesive layer, LD groups were higher than LU groups, and no significant difference in stress peak was found among different experimental groups in the same material. In addition, fiber posts in double root canals could significantly reduce buccal tip displacement.@*CONCLUSIONS@#For pulp-penetrating non-carious cervical lesions, the restorative strategy of surface-mounted inlays could be applied. Compared with Lava Ultimate, IPS e.max CAD could better protect the defective tip tooth. Furthermore, fiber posts in double root canals could decrease overall deformation and increase the retention of surface-mounted inlays.

Application of epiglottis with sternohyoid muscle in the surgery for laryngeal cancer / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore and evaluate the application of epiglottis with sternohyoid muscle in the surgery for laryngeal cancer.</p><p><b>METHODS</b>Two fifty patients with laryngeal cancer were treated by partial laryngectomy and the laryngeal defects were reconstructed by epiglottic flap and sternohyoid muscle fascia flap. The staging of tumors: T2N0M0 23 cases, T3N1M0 14 cases, T3N2M0 13 cases. All of them received post radical radiotherapy with average 60 Gy. The patients were followed up for 3 to 5 years. Thirty patients underwent neck dissection.</p><p><b>RESULTS</b>The three and five years survival rates were 90% and 80% respectively. The total cases eat breath pronounced well. The decannulation rate was 96%.</p><p><b>CONCLUSION</b>After partial laryngectomy in laryngeal cancer epiglottic flap and sternohyoid muscle fascia flap were performed reconstruction of laryngeal function.</p>