Tap chi THONG TIN YDlfOC Sd 1 ndm 2010
HE THONG SO KHONG KIM LOAI LITHIUM DISILICATE IPS EMPRESS 2 - SU LUA CHON CHO PHUC HJNH RANG CO DjNH
Chu Thi Quynh Hifdng*
Hien nay, vdi sif phat trien vu'dt bac cua khoa hoc cong nghe, vat lieu sd ngay cang difdc nghien cdu de gia tang do ben, tham my tu' nhien, trong do he thdng toan sd la vat lieu de thay the chup thep can sd va du'dc chi dinh cho nhieu muc dfch khac nhau.
I . OAT VAN OE
IPS Empress 2 la vat lieu toan sii' cd cdng thirc hda hgc hoan toan mdi thudc sii' thiiy tinh cd ty le thanh edng eao vdi chi djnh lam sang md rgng. Cdng nghe che tao chup la lam mat sap va nen ndng sir vao khudn rat ddn gian va quen thudc. Nghien ciTu lam sang da chi ra nhieu Uu die'm ciia he thdng sir IPS Empress 2.
I I . THANH PHAN
Sir IPS Empress 2 sir dgng ky thuat phii Idp bao gom hai loai sir thiiy tinh khac nhau: sir khung va sir phii d tren (sir veneer).
1. Su'khung
IPS Empress 2 ed sir khung la eiiu true sir thiiy tinh lithium disilieate ed cdng thu'c Si02 - LiaO, chiem tren 60%, eau true nay bao gdm cac tinh the lithium disilieate dai khoang 0,5pm- 5gm, hinh the dong nhat, xep xen ke day dac ddng deu, ket dfnh trong igdi thiiy tinh. Them vao dd la cac tinh the lithium orthophosphate nhd dai tir 0,l-0,3pm. Cau true phirc hdp nay ngan can sg ran nut day chuyen, nang cao do chdng gay v9 va do udn ciia vat lieu tdi khoang 340±20MPa.
2. Sit phu (hay sit thuy tinh nung) Sir khung du'dc phii mgt Idp sir nung. Sir phii la cac dang bdt vdi mau nga, men, canh can,... bao gdm tinh the fluor apatit. Sir phii dggc nung ndng phii len sir khung d nhiet do 800°C. Khi nung cac tinh the apatit phan tan ket tiia trong igdi thiiy tinh, cae tinh the tang cgdng do tgong hdp sinh ly ciia sir thiiy tinh v^ tao dggc cae dae tfnh quang hgc nhg do trong md, do sang, khuyech tan anh sang ciia sir phii, vi vay khi phgc hdi cd dae tfnh quang hgc tgong t g nhg rang t g nhien.
I I I . U'U O I E M
1. Titdng hap sinh hoc
Od ben sir khung cao cho phep gia edng sir va danh bdng de, tao sat kbit d bd chup rang, giam tao mang bam do be mat sir mjn va bdng hdn so vdi kim loai, hoac sir kim loai.
2. Dp ben va do chong gay
Theo Studer va Sehater (1998), chup rang suT toan phan lam tir IPS Empress 2 cd ty le thanh edng la 97%. Ty le thanh cdng ciia Inlay, onlay lam tir vat lieu nay trong cac nghien cuU lam sang cung rat eao. Trong khi dd, theo Sorensen, Cruz va Mito, IPS Empress 2 ben gap 3 lan IPS Empress. Su'c chdng gay v8 cung tang len 3 lan do ed ham igong tinh the cao.
Do diroc nung ndng tai ndi san xuiit dgdi cac dieu kien kie'm soat chat che, sir nen cd chat Iu'dng cao va rat ft vet nirt. Giam tdi da cac vet nirt trong eiiu true su' rat quan trgng ddi vdi tud'i thg lam sang ciia eau rang, vi cae vet nirt se lam phat sinh hien tu'dng ran nut day chuyen, dan den that bai lam sang.
3. Do mdn tu'dng hdp
Cau true mjn va ham lu'Ong tinh the cao ciia sir thiiy tinh lam giam kha nang rang ddi bj mdn. Nung sir phii fluor apatit vao sir khung tao ra cac tinh the apatit tgOng t g nhg ciiu true rang t g nhien. Mgt nghien ciTu thf nghiem md phdng do mdn trong mieng ciia Sorensen, Sultan, Condon (OHSU) danh gia mdn ba chieu, thir do mdn gay ra bdi cac loai sir khac nhau thay rang IPS Empress 2 gay mdn ft nhiit. Thanh phan ciia su' phii fluor apatit md phdng chfnh xac cau triic rang t g nhien hOn sir kim loai thdng thgdng (sir feldspathic). Sau 6 thang, mdt nira cac rang dgdc xet nghiem cd do mdn riit nhd, khdng the do dggc. Chi khoang 40% matcan cua siJbi mdn. The tfch mdn trung binh (mm^) ciia rang t g nhien la
* ThS., Benh vien Rang Ham Mat TW Ha Npi
Tap chi THONG TIN YDlfOC Sd 1 ndm 2010
0,0701±0.121, ciia sir la 0,268±0,370. Theo Sorensen, Cruz va Mito (1999), day la ket qua nghien ciru lam sang dau tien cho thay sir eg xat rat nhe len rang t g nhien.
4. Bao ton mo rang
Trgdc day, nha sy thgdng eho rang cac gu die'm ciia chup sir toan phan ehi cd du'dc khi mai nhieu rang hdn. Sorensen va cdng sg (1998) trong mgt nghien eiru lam sang ve chup leucit nen, gan dan (IPS Empress) thay rang ehi can mai 1,3mm xung quanh la dii.
Mdt lgi the ciia loai sir ben la ed do trong md nay va giam md rang can mai khi lam chup sir toan phan. Trong khi chup thep can sir can mai 1,4mm den 1,7mm xung quanh thi chup sir gan dan IPS Empress 2 chi can mai 1mm, vi the he thdng nay bao tdn md rang nhieu hOn.
5. Cac u'ng dung khac
Cdng nghe sif gan dan cd the sir dung de che tao cau rang, sir dung inlay, onlay lam tru eau, bao tdn rat nhieu md rang. Tham my eao se dat dggc do resin chay ciing mau vdi sir khung trong md va rang tru cau hda hop vdi nhau.
6. Ldi the ciia su' nen
IPS Empress 2 sir dung ky thuat mau sap, sir nen quen thugc va thdng thgdng ddi vdi cac ky thuat vien. Qua trinh che tao eac he thdng sir khac bao gdm nhieu bgde phiTe tap, chi can tao dang khung chup bang sap tren dai, sau dd la nen.
Thdng thgdng trong dieu tri lam sang, khi mai rang can them cac ranh lug hoac hop d cae mat ben, eon vdi IPS Empress 2 cd the tai tao lai cac ranh hoac hop nay, vi vay ed the irng dung rgng rai hdn.
7. Chi dinh
- Phuc hinh cau ba ddn vj cho viing rang trgdc va viing rang ham nhd (tru xa la rang ham nhd thir hai).
- Chup cho viing rang trgdc va rang sau.
IV. KY THUAT GAN CHUP
Ky thuat gan dan eho phep nha sy bao ton md rang nhieu hOn va ehi mai xung quanh khoang 1mm, de dat du'dc hieu qua tham my tggng tg, chup thep can sif phai mai nhieu rang hdn gap 1,5 lan. Tuy nhien, trong trgdng hop rang khdng giCf ddOc dii khd de sir dung ky thuat dan (dgdi lOi), liic dd sir dung Glass lonomer Cement ed do sieu nd thap (ProTec
CEM) de gan chup sif toan phan va cau lam bang IPS Empress 2.
Tru'dc phuc hinh
Mai cui rang
• • ^
H1c ' - ^
Lol sd
Chup sd
Benh nhan sau lap
Hinh 1: Quy trinh BN phuc hinh lai hai rang cda Rll, R21 bang IPS Empress 2
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Tap chi THONG TIN YDlfOC Sd 1 ndm 2010
V. KET LUAN
He thdng sif thiiy tinh IPS Empress 2 danh dau mdt bgde tien vggt bae trong viec phuc hdi hinh dang, chife nang va tham my ciia ham rang 6[i<ic phuc hinh. Cdng thifc vat lieu duy nhift dga vat lieu nha khoa phat trie'n len mgt bgde trong viee md phdng chifc nang va ciiu true eiia rang that. Thanh cdng lam sang eiia vat lieu nay khi chua'n bj va che tao theo dung qui trinh cho phep nha sT t g tin phue hoi rang da mat. IPS Empress 2 cho phep tao phuc hdi vdi tgdng hOp sinh hgc tdt hOn vl do day can mai xung quanh rang ft di, kha nang gay viem ldi va nha chu do phuc hdi rang giam han va rang t g nhien d ham ddi ft mdn hOn so vdi khi diing sif kim loai thdng thgdng hoac cac loai sir khac.
T A I LIEU THAM KHAO
1. Schweiger M., Holand W., Franic M. et al: IPS Empress 2 new pressable high-strength glass- ceramic for esthetic all-ceramic restoration. Quin Dental Tech. In press, 1999.
2. Severance G.: Introducing a lithium disilieate restorative: An all-ceramic altemative. Signature, 1998, 5(3),pp.l-3.
3. Shillingburg H.T., Jacobi R.: Anterior porcelain- fused-to-metal crowns. In: Bracket SE, ed.
Fundamentals of Tooth Preparations for Cast l^letal and Porcelain Restorations. Chicago, IL:
Quintessence Publishing Co, 1987, pp.259-278.
4. Sorensen J.A., Choi C , Fanuscu M.I., Mito W.T.:
IPS Empress crown system: Three-year clinical trial results. J Calif Dent Assoc, 1998, 26(2), pp.130-136.
5. Sorensen J.A., Sultan E., Condon J.R.: Three- body in vitro wear of enamel against dental ceramics.
J Dent Res. Submitted.
6. Studer S., Scharer P.: Seven-year clinical results of IPS Empress inlays and onlays. J Dent Res 1998, pp.77.e
SO CAN BO NGANH Y THUOC SO Y TE NAM 2008 (ciia trung du vd mien niii phia Bdc)
Don vi tfnh: ngudi
Ten Ha Giang Cao Bang Bac Kan Tuyen Quang Lao Cai Yen Bai Thai Nguyen Lang SOn Bac Giang Phil Thg Oien Bien Lai Chau Sdn La Hoa Binh
T o n g
Bac si 405 423 329 416 375 503 705 596 951 749 244 116 511 458 6.781
Ysi 899 675 320 499 606 742 492 717 1154 1101 746 653 907 875 10.386
Vta 142 526 426 342 686 553 946 624 1053
676 485 452 797 466 8.184
NO'ho sinh 359 335 93 103 344 358 152 299 279 170 203 183 344 152 3.374 (Nguon: Nien giam thdng ke 2008)
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