Billington R W, Williams J A, Pearson G J
Biomaterials Department, Institute of Dental Surgery, London.
Br Dent J. 1990 Sep 22;169(6):164-7. doi: 10.1038/sj.bdj.4807311.
This study investigates the powder/liquid ratios of a glass-ionomer restorative (ChemFil II, Dentsply) mixed in clinical practice. Twenty-two dental surgery assistants (11 from general practice; 11 from a dental hospital) mixed this cement as they would for clinical use. Samples were taken of three mixes from each assistant and the powder/liquid ratios were derived from weight loss on dehydration. A wide range of ratios were obtained, but in no case was the manufacturer's recommended ratio of 6.8:1 achieved. The consistency measured in accordance with BS 6039 showed the cement at 6.8:1 to be less fluid than the requirements of the standard and other glass-ionomer restoratives. When tested at the mean ratio used in practice, 5.0:1, the consistency complied with BS 6039, but the compressive and diametral strengths did not, being about half the values found at 6.8:1. It was concluded that this restorative was often mixed in practice at much lower powder/liquid ratios than that recommended by the manufacturer and that this would impair the cement's mechanical properties.
本研究调查了临床实践中混合的玻璃离子修复材料（ChemFil II，登士柏公司）的粉液比。22名牙科手术助手（11名来自综合诊所；11名来自牙科医院）按照临床使用的方式混合这种粘结剂。从每位助手混合的材料中取三份样品，并通过脱水失重得出粉液比。得到了广泛的比例范围，但在任何情况下都未达到制造商推荐的6.8:1的比例。按照英国标准BS 6039测量的稠度表明，6.8:1的粘结剂比标准和其他玻璃离子修复材料所需的流动性小。当以实际使用的平均比例5.0:1进行测试时，稠度符合BS 6039，但抗压强度和直径拉伸强度不符合，约为6.8:1时发现值的一半。得出的结论是，在实践中，这种修复材料的粉液比常常远低于制造商推荐的比例，这会损害粘结剂的机械性能。
