Enamel: Cov txheej txheej saum npoo ntawm tus hniav sib tsoo, pom kev pom tseeb, milky dawb calcified nqaij, muaj 96% inorganic teeb meem, 4% dej thiab cov organic.
Dentin: lub cev tseem ceeb ntawm tus hniav, lub teeb daj thiab ci, muaj 70% inorganic tshuaj thiab 30% organic tshuaj. Muaj cov hlab paj hauv qhov chaw kho hniav, uas yog qhov ua kom mob.
Cementum: Ib txheej ntawm calcified sib txuas cov ntaub so ntswg nyob rau saum npoo hniav. Nws yog lub teeb daj hauv cov xim thiab muaj 55% tshuaj lom. Nws muaj pes tsawg leeg thiab lub zog ua haujlwm zoo ib yam li cov pob txha tab sis tsis muaj lub raj Haval. Cementum muaj cov haujlwm tshiab.
Hniav pulp: Cov leeg xoob hauv cov nqaij mos hauv cov kab noj hniav, muaj cov hlab ntsha, hlab ntsha hauv lub cev, cov hlab ntsha, fibroblasts thiab odontoblasts, muaj peev xwm tsim cov hniav ntawv theem nrab. Cov hniav sib tsoo hniav yog ib qho hlab tsis muaj pa thiab tsis muaj peev xwm muab tso rau. Cov hlab ntshav nkag thiab tawm ntawm qhov nqaim apical foramen, uas tuaj yeem yooj yim ua rau kev cuam tshuam thiab mob ntsws.