THE APPLICATIO OF EXPERIMENTAL RESIN COMPOSITES ATTRACTIVE TO MAGNET FOR DENTAL MAGNETIC ATTACHMENT

这种新型实验复合材料具有良好的保质期，并且在修复过程中易于处理。当每100g不锈钢填料加入1.5g γ - MPTS（70%乙醇溶液）处理时，该复合材料的最大抗弯强度为7.7kgf/mm^2， Knoop硬度值为64。然而，为了临床应用，该复合材料的力学性能需要改进。在37ºC的1%乳酸溶液中浸泡7天后，复合材料中金属的洗脱总量为0.7mg/cm^2。该值符合日本牙科铸造镍铬合金的批准规格（1mg/cm^2）。利用下颌模型进行的引力测量显示，与磁铁/托架系统相比，磁铁/复合系统的引力降低了25%。

This new experimental composite has a good shelf life and can be easily handled during restoration.The maxmal flexural strength and the Knoop hardness value of this compositewere 7.7kgf/mm^2 and 64 respectively, when the filler was treated with 1.5g gamma MPTS in 70% ethanol solution per 100g of stainless steel filler. However mechanical properties of the composite require improvement for clinical application.After immersion in 1% lactic acid solution at 37ﾟC for 7 days, the total amount of metal eluted from the composite was 0.7mg/cm^2. This value is under the Japanese apporval specifications for dental casting Ni-Cr alloys (1mg/cm^2).The attraction force measurement using mandibular model showed a 25% decrease in attraction force of the magnet/composite system compared to that the magnet/keeper system.