Stress analysis of magnetic attachment in mandibular complete overdenture supported by nature roots and implants / 吉林大学学报(医学版)

Objective To analyze the stress state of magnetic attachment in mandibular complete overdenture supported by nature roots and implant, and to provide neference for designing of clinical prosthodentics. Methods Three-dimensional finite models (model,Ⅱ,Ⅲ)of three groups of mandibular overdentures depending on the different location of the implant and natural tooth root, placing three pairs of magnetic attachment, were constructed by application of CT scanning,computer photo processing system,and Solidworks finite element model building software.The natural teeth and implant neck bone stress of the models in three groups under different stress were calculated and compared.Results The stress of the bone around the implant in the area of molar teeth in model with both sides of the implants under oblique load (Model Ⅱ)was significantly increased compared with the model with one side of the implant (Model Ⅲ). The supporting bone stress of oblique load was increased compared with the vertical load;among them under the oblique load at one side’ s molar teeth, the stress of the bone around the implant in the area of molar teeth in modelⅠ,modelⅡ and model Ⅲ was increased about 30%, 43%,and 55%.Conclusion When there only one nature teeth remain,two implants should be at least added, one in the area of opposite cuspid, and the other in the area of molar teeth of the same side. The magnetic attachment is better than other kinds of attachment in preventing the damage of abutment when it suffers inclined load.

A clinical analysis on treatment of patients who suffered from acute exacerbations of chronic obstructive pulmonary disease with typeⅡrespiratory failure / 中国基层医药

Objective To study the effect of noninvasive pressure venrilation(NIPPV) on the treatment of acute exacerbarions of chronic obstructive pulmonary disease(COPD) with typeⅡrespiratory failure. Methods 46 cases of COPD were selected to treat with NIPPV in our hospital from 2001 January to 2005 May. The data in arterial blood gas(pH,PaO2,PaCO2),the course of disease in the hospital,the rate of endotracheal intubation, the mortality of the patients in NIPPV were analyzed and compared with those of the patients without NIPPV treatment before. Results The datas in arterial blood gas had been imprived significantly in NIPPV after 24h.The couse of disease in hospital was significantly shkrter,and the rate of endotracheal intubation and mortality of the patients was significantly lower in NIPPV than those in no NIPPV. There was remarkably difference between two groups. In NIPPV, the rate of endotracheal intubation were significantly lower in light and moderate trspiratkry failure than those in severe respiratory failure(P