Vim hais tias cov rwb thaiv tsev filling ua rau saum npoo ntawm lub rhaub dej tsis raug them, ces yuav ua li cas cov rwb thaiv tsev ntawm cov hluav taws xob cua sov tsis yog hygroscopic?
Ua ntej, xaiv lub siab purity hloov magnesium oxide hmoov (cov ntaub ntawv rwb thaiv tsev);
Qhov thib ob, uas yog, qhov hluav taws xob cua sov qhov chaw nres nkoj yog siv kom raug kaw (raws li kev xaiv cov khoom siv hluav taws xob cua sov lub raj sealing, peb yuav qhia kom meej tom qab)
