大锥度牙胶尖热收缩性能的评价

Evaluation of shrinkage by heat of 0.6-taperd gutter-perchas

目的观察4种不同品牌的0.06锥度的牙胶尖的热收缩性能。方法将4种牙胶尖末端固定在同一带刻度的平板上,尖端处于同一水平线,此水平线作为读数的零点,从30℃开始记录其长度变化;根据加热介质分为:A组,水浴加热;B组,甘油浴加热,采用Spss 13.0 for windows(English version)统计软件对结果进行相关分析。结果在50℃时4种不同品牌的牙胶尖都可以发生体积变化。牙胶尖的长度变化和温度具有明显的相关性。各牙胶尖之间的差别无统计学意义。不同的加热介质所出现不同的尺寸变化有统计学意义。结论4种不同品牌的牙胶尖分别在蒸馏水和甘油中加热,在50℃以上出现发生不同的热收缩,其在不同介质中发生变化不尽相同,提示在临床中不同根管封闭剂时可能发生不同的热收缩。

Objective To observe four different brands of O. 06 gutter-percha＇s dimension changes when they are heated in different circumferential media. Method We attached the four different brands of 0.06 gutter-perchas to the same plane with the same length. Their tips were placed on the same line and we noted the length changes from 30℃. The same procedures were carried out in water and glycerol five times. The data were analyzed by SPSS 13.0 for windows for their correlations. Result At the temperature of 50 ℃, the four brands of GP all had dimensional changes, and the length shrinkage by heat was almost less than 0.5 mm until the 80 ℃. Conclusions As the four different brands of GP were heated in water and glycerol, there were different dimensional changes when the temperature was over 50 ℃. And the length changes were different as the circumferential media were different, which might indicate when GP was put into different sealers in clinical practice, they might have different dimensional changes when heated. The result from this test was the four different brands of GP all had dimensional stability in normal temperature.