Cov hniav yog ib feem tseem ceeb ntawm tib neeg lub cev, nrog rau qhov qhia txog kev noj qab haus huv. Lawv txoj kev poob ua rau muaj teeb meem loj hauv plab hnyuv, thiab qhov zoo nkauj ntawm tus neeg deteriorates. Tab sis feem ntau cov hniav raug rau ntau yam kab mob, feem ntau ntawm tag nrho cov caries. Nyob rau hauv cov ntaub ntawv no, kev puas tsuaj cuam tshuam tsis tau tsuas yog cov enamel, tab sis kuj cov pob txha tshuaj, uas ua rau mob ntawm ib tug nruj xwm.
Tooth structure
Hniav yog tib neeg lub cev uas nyob rau hauv lub alveoli ntawm lub puab tsaig thiab anatomically muaj ib tug crown, cag thiab caj dab, uas, tapering, txuas lub crown mus rau hauv paus.
Morphologically, nws muaj cov tawv nqaij thiab mos. Cia peb xav txog ntau yam ntxiv. Enamel, uas yog qhov nyuaj tshaj plaws hauv tib neeg lub cev, npog lub coronal, uas yog, qhov pom ntawm cov hniav, thiab hauv qab nws yog cov pob txha ntawm cov hniav. Txwv tsis pub, nws yog hu ua dentin, uas nyob rau hauv nws cov qauv yog heev mos thiab ntxeem tau. Nws cov hauv paus hniav nyob rau hauv cov pos hniav yog them nrog cementum, thiab nyob rau hauv cov hniav yog hollow, thiab cov void no yog sau nrog pulp, ib tug mos mos ntaub so ntswg uas muaj cov hlab ntsha thiab cov hlab ntsha. Lawv nkag mus rau hauv cov qauv ntxeem tau ntawm lub dentin thiab mus txog qhov pib ntawm cov enamel. Qhov no yog qhov ua rauhypersensitivity thaum lub sij hawm tam sim ntawd hloov nyob rau hauv qhov kub thiab txias nyob rau hauv lub qhov ncauj kab noj hniav, raws li zoo raws li nyob rau hauv cov kev cuam tshuam ntawm lwm yam tsis zoo tshwm sim.
Dentine
Cov pob txha ntawm cov hniav ua rau nws lub ntsiab, nyob rau hauv lub coronal cheeb tsam nws yog them nrog enamel, thiab nyob rau hauv cov pos hniav cov hauv paus hniav muaj ib lub plhaub ntawm cov cement. Dentin yog cov khoom txhawb nqa, uas yog qhov tseem ceeb heev, vim nws ua haujlwm ntawm kev tiv thaiv cov tawv nqaij los ntawm cov stimuli sab nraud.
Cov pob txha ntawm cov hniav yog qhov thib ob muaj zog tshaj plaws hauv lub cev tom qab enamel, txawm tias nws cov qauv xoob. Ib feem tsib ntawm cov ntaub so ntswg no muaj collagen, ob feem peb ntawm inorganic tshuaj, thiab 10% yog dej. Yog hais tias peb soj ntsuam cov dentin nyob rau hauv ib lub microscope, peb yuav pom tau hais tias qhov no yog ib tug intercellular tshuaj unevenly them nrog txiv qaub deposits. Nws yog permeated los ntawm ib tug lossis loj tus naj npawb ntawm dentinal tubules, uas muaj cov hlab ntsha xaus ntawm lub pulp.
Cov pob txha ntawm cov hniav muab faib ua peb hom: Qhov tsim ntawm dentin yog tus kheej thiab nyob ntawm ntau yam, piv txwv li, cov hniav hnav lossis lwm yam tsis xws luag uas hloov dentin tshwm sim nrog ntau qhov sib txawv ntawm kev siv. Nov yog cov ntaub so ntswg hnyav tshaj plaws thiab muaj zog tshaj plaws hauv tib neeg lub cev, yuav luag tag nrho cov zaub mov thiab tiv thaiv cov dentin thiab pulp. Nws txheej thinnest yog nyob ntawm caj dab ntawm cov hniav, thiab cov tuab tshaj plaws - ntawm cov zom tubercles. Enamel lub zog tsis tas li, hloov ntawm qhov pib ntawm kev loj hlob ntawm cov hniav mus rau qhov kawg. Yog li, tom qab tawg, nws tsis muaj zog ntau dua li tom qab ob peb xyoos, txij li nws cov mineralization tseem tsis zoo. Tab sis ntau xyoo, lub zog ntawm cov ntaub tseem txo qis. Nws nyob ntawm ntau yam. Tsis tas li ntawd, lub zog ntawm cov enamel sib txawv hauv ntau qhov chaw ntawm cov hniav. Qhov kev teeb tsa no kuj yog tus kheej. Tab sis ib qho tshwj xeeb yog tib yam rau txhua tus: cov txheej saum toj kawg nkaus ntawm cov ntaub yog ib txwm muaj zog tshaj plaws, nws cov qauv tsis sib xws, thiab qhov porosity yog negligible. Qhov ze ntawm cov enamel txheej yog rau lub dentin, qhov ntau xoob nws cov qauv ua, thiab raws li, lub zog txo. Feem ntau, cov pob txha ntawm cov hniav feem ntau ua rau muaj mob xws li caries. Yog hais tias qhov kev puas tsuaj cuam tshuam tsuas yog dentin thiab enamel ntawm cov hniav, tus kab mob yog cais raws li nruab nrab, nrog rau kev puas tsuaj ntawm cov hauv paus hniav, nws daim ntawv sib sib zog nqus. Nws tag nrho pib nrog kev puas tsuaj rau cov ntaub so ntswg, cov tsos ntawm carious kab noj hniav uas muaj cov khoom noj khib nyiab,uas pab txhawb rau qhov pib ntawm cov txheej txheem ntawm kev lwj thiab kev puas tsuaj ntxiv ntawm cov hniav. Qhov chaw mob ua rau muaj qhov tsis xis nyob, teb nrog qhov mob hnyav hauv cov lus teb rau ntau yam stimuli, tab sis sai li sai tau thaum lawv sib cuag nrog qhov chaw mob, qhov mob ploj mus. Qhov no yog vim li cas thiaj mus ntsib kws kho hniav sai li sai tau thiab kho qhov teeb meem. Txwv tsis pub, caries yuav ncav cuag lub hauv paus ntawm cov hniav nyob rau hauv ib tug luv luv lub sij hawm, tom qab uas muaj feem ntau yuav poob nws. Yuav kom koj cov hniav noj qab nyob zoo kom ntev li ntev tau, koj yuav tsum ua tib zoo saib xyuas qhov ncauj, noj cov zaub mov noj qab haus huv uas muaj cov vitamins thiab minerals, thiab tsis tu ncua kev kuaj hniav kom pom cov ntaub so ntswg puas thaum ntxov, tiv thaiv lawv kev puas tsuaj.
Enamel
Dentinal disease
