摘要
目的研究快速石膏基包埋料在调拌混合后放置不同时间再进行不同的热处理对材料膨胀性能的影响。方法采用CristoquickⅡ石膏基快速包埋料,测量材料从调拌结束至调拌完成后2h内的凝固膨胀率,以及材料在调拌后分别放置30、60和120min后采用快速和常规加热法处理的热膨胀率,然后计算包埋料的总膨胀率。采用SPSS11.0统计软件分析包埋料在调拌后放置不同时间和不同热处理法膨胀率的差异。结果调拌后放置时间不同,包埋料的膨胀率差异有统计学意义(P<0.01);随放置时间的增加,凝固膨胀率增加,经快速和常规热处理后的总膨胀率也呈增加趋势。在相同的放置时间内,经快速热处理和常规热处理的总膨胀率差异无统计学意义(P>0.05)。结论不同热处理时机对快速石膏基包埋料膨胀性能有影响,快速加热处理所产生的材料总膨胀率(1.60%)低于某些牙科合金的铸造收缩量,调拌后延长放置时间再进行快速热处理可改善匹配性。
Objective To study the effects of different heating timings after mixing the materials and different heating methods on the expansion characters of a quick-heating gypsum-bonded investment. Methods The setting expansion rate of GC Cristoquick Ⅱ gypsum-bonded investment was measured with a setting expansion tester 30, 60, 120 min after mixing the material respectively. The thermal expansion rates of the material at different setting time （30, 60, 120 min after mixing） and under different heating treatment methods （quick and conventional heating techniques） were also determined using a thermal dilatometer for dental investments, the total linear expansion rate were calculated. The effects of heating time and heating methods on the expansion of the investments were statistically analyzed with SPSS 11.0 software, using ANOVA multiple comparison （α=0.05）. Results Statistical differences were found among the setting and thermal expansion rates of the investment at different heating timings after mixing the material （P〈0.01）. Setting expansion, thermal expansion and total expansion rates increased with the setting time before heat treatment, while thermal expansion rates under different （quick and conventional） heating methods were not statistically significant （P〉0.05）. Conclusion The expansion characters of the quick-heating gypsum-bonded investment are influenced by different heating timings after mixing the material. The heat treatment technique of this quick-heating investment recommended needs to be modified to ensure casting precision.
出处
《华西口腔医学杂志》
CAS
CSCD
北大核心
2008年第2期179-182,共4页
West China Journal of Stomatology
关键词
石膏基包埋料
凝固膨胀
热膨胀
快速加热
gypsum-bonded casting investment
setting expansion
thermal expansion
quick heating
