Zirconia yas
May 13, 2019| Zirconia yog ib qho nyuaj heev uas siv los ua ib qho khoom siv hauv paus hauv qee lub qhov ua kom tiav. Zirconia yog ib qho tshiab hauv kev kho hniav thiab cov ntaub ntawv tshawb fawb tau muab coj los kuaj. Lub zirconia siv hauv kev kho hniav yog zirconium oxide uas tau muaj kev ruaj ntseg nrog qhov sib ntxiv ntawm yttrium oxide. Lub npe tag nrho ntawm zirconia siv hauv kev kho hniav yog yttria-stabilized zirconia lossis YSZ.
Lub zirconia substructure (core) feem ntau yog tsim los ntawm cov sawv cev ntawm tus neeg mob lub qhov ncauj, uas yog ntes nrog 3d kev kuaj ntawm tus neeg mob, lub tswv yim, lossis qauv. Cov tub ntxhais kawm yog los ntawm cov pob zeb ntawm zirconia hauv ib lub xeev muag ua ntej. Thaum cov milled, zirconia yog sintered nyob rau hauv lub cub hluav taws uas nws shrinks los ntawm 20% thiab nce mus txog nws lub zog tag nrho ntawm 850MPa los 1000MPa.
Lub zirconia core qauv yuav muab fawm nrog cov ntaub so ntswg zoo li feldspathic porcelain los tsim cov xim kawg thiab cov duab ntawm tus hniav. Vim tias daim ntawv cog lus muaj zog ntawm cov fais fab (folding porcelain fused) rau zirconia tsis muaj zog, "monolithic" zirconia crowns yog feem ntau ua los ntawm cov zirconia ceramic uas tsis muaj cov ntaub so ntswg zoo li cov plooj (veneers) rau saum toj. Zirconia yog qhov nyuaj tshaj plaws nyob rau hauv kev lag luam thiab cov khoom siv siv hauv kev kho hniav. Monolithic zirconia crowns yuav ua opaque nyob rau hauv tsos nrog ib tug high nqi thiab lawv tsis muaj translucency thiab fluorescence. Rau qhov xav tau ntawm cov tsos, ntau tus kws kho hniav yuav tsis siv cov khoom yas rau sab hauv (sab hauv).
Rau ntau qhov, xaiv cov ntaub ntawv hauv kev kho hniav txiav txim lub dag lub zog thiab zoo li ib lub yas. Qee lub ntsiab lus ntawm cov zirconia tsim cov khoom siv khomob tshaj plaws hauv kev kho hniav (lub zog ntawm qee lub zirconia crown khoom ze li 1000MPa.), Tab sis cov plaub hau no feem ntau tsis pom tias yog txaus txaus rau cov hniav nyob sab hauv lub qhov ncauj; txawm tias tsis muaj zog, qee cov ntaub ntawv tshiab zirconia yog cov zoo li cov tsos, tab sis lawv tseem tsis feem ntau zoo li porcelain fused crowns.
Thaum plooj (veneers) fused mus zirconia tseem ceeb, cov crowns yog ntau tshaj ntuj tshaj monolithic zirconia crowns tab sis lawv tsis muaj zog. Ntawm qhov sib piv, thaum porcelain fused mus iav infiltrated alumina, crowns yog ntuj heev-saib thiab muaj zog heev, tab sis yog tsis muaj zog li monolithic zirconia crowns. Lwm cov khoom siv lithium-disilicate, ua rau cov pob zeb uas muaj feem xyuam xim muaj zog heev uas feem ntau tshwm sim rau hauv lub qhov ncauj, thiab kov yeej qhov no, lub teeb ntxoov ntxoo kom muaj xim zoo nkauj, tsis tshua pom kev dawb. Lwm cov khoom siv khoom yas kom pom tias yog thermal conductivity thiab radiolucency. Kev ruaj ntseg / looseness ntawm haum rau ntawm cov hniav thiab cov cement sib npaug ntawm cov paj tau paj yog qee zaum muaj feem xyuam nrog cov khoom xaiv, tab sis cov khoom siv hauv cov khoom no tseem muaj feem xyuam nrog cov txheej txheem thiab tsim cov txheej txheem.