Iningi labathengi bamazinyo lihlola i-PMMA ngentengo kanye nokutholakala kwayo. Kodwa ngokolwazi lwethu lokusebenza nama-lab kanye nabasabalalisi kulo lonke imboni, izinqumo eziholela ekubuyiselweni emuva kwemithi, ukwenziwa kabusha, kanye nabasebenzisi bokugcina abangajabule cishe njalo zibuyela emuva esicini esisodwa esinganakwa: ukuthi izinto ziqondwa kahle kangakanani ngaphambi kokuba zi-odwe.
I-PMMA — i-polymethyl methacrylate — ingenye yezinto ezisetshenziswa kakhulu ekwenziweni kwamazinyo kwanamuhla. Iyaguquguquka, iyahambisana ne-bio, inamandla ngobuhle, futhi ihambisana ngokujulile nemisebenzi yanamuhla ye-CAD/CAM. Kodwa njenganoma iyiphi impahla, inesivikelo sokusebenza. Ukwazi ukuthi leyo mvilophu iphelela kuphi yikho okuhlukanisa isinqumo sokuthenga esihlakaniphile nesebizayo.
Lesi sihloko sihlanganisa amaqiniso ayi-5 abalulekile ngezinto zamazinyo ze-PMMA: ukuthi iyini nokuthi yenziwa kanjani, ukuthi kungani isebenza kahle kangaka ezimweni eziningi zezokwelapha, lapho kukhona khona imikhawulo yayo yangempela, ukuthi isetshenziswa kanjani kuzo zonke izigqoko, amazinyo okufakelwa, kanye nezinqubo zokufakelwa, kanye nokuthi yini elandelayo kubuchwepheshe be-PMMA. Kungakhathaliseki ukuthi uthengisa ilebhu eyodwa noma uthola ngezinga elikhulu, lezi yizinto okufanele uzazi.
I-Polymethyl methacrylate iyi-polymer ye-thermoplastic — empeleni i-resin ye-acrylic yokwenziwa — eyakhiwe ngokuxhumanisa ama-monomers e-methyl methacrylate kumaketanga amade, azinzile ngenqubo ebizwa ngokuthi i-polymerization. Umphumela uba yinto ecacile, elula, futhi emelana nokuqhekeka ngokuphawulekayo uma kuqhathaniswa nengilazi noma i-porcelain yendabuko.
Kwezokwelapha amazinyo, i-PMMA ibilokhu isetshenziswa amashumi eminyaka. Ayizange ithole indawo yayo ngokumaketha kodwa ngokusebenza kahle kwezokwelapha: ithembekile, iyabikezelwa, futhi kulula ukuyisebenzisa ezindaweni ezahlukene zelebhu.
Okwenza i-PMMA ibe usizo kakhulu ekusetshenzisweni kwamazinyo yinhlanganisela yezakhiwo ezine eziyinhloko:
• Ukukhanya: Izakhiwo zayo zokudlulisa ukukhanya zilingisa kakhulu i-enamel yemvelo, yingakho ukulungiswa kwe-PMMA kuhlangana ngokwemvelo emlonyeni.
• Ukumelana nokuqhekeka: Ngokungafani ne-ceramics yengilazi, i-PMMA imunca umthelela kunokuba iqhekeke, okunciphisa ingozi yokwehluleka okungazelelwe.
• Ukuhambisana kwezinto eziphilayo: Ibekezelela kahle izicubu zomlomo, inomlando omude wokusetshenziswa okuphephile.
• Ukonga izindleko: Iletha imiphumela emihle yobuhle ngentengo encane kakhulu kune-zirconia noma ezinye izindlela ze-ceramic egcwele.
I-PMMA ejwayelekile iqukethe ama-monomers e-MMA, amaketanga e-polymer okuqina kwesakhiwo, kanye nama-plasticizer okuzikhethela ukuze kube nokuguquguquka. Okubalulekile kubathengi nasema-lab ukuthi lokhu kuhlanganiswa akulungisiwe — kungalungiswa. Amafomula ahlukene afanela izinhlelo zokusebenza ezahlukene, futhi abakhiqizi abadumile banikeza amabhlogo e-PMMA ahlukahlukene ngobuningi, izinketho zomthunzi, kanye namaphrofayili emishini.
Ukuqonda lokhu kuhlukahluka kusiza amalabhorethri kanye namaqembu okuthenga ukuthi acacise izinto ngokunembe kakhudlwana, futhi kunciphisa ukuzama-nephutha okuvela ekuphatheni yonke i-PMMA njengokungashintshaniswa.
I-PMMA ihlala isikhathi eside ngokwesigaba sayo. Ezimweni ezivamile zokuvaleka - ukuhlafuna, ukugaya, nokuluma nsuku zonke - ukulungiswa kwe-PMMA kuhlala kahle. Imiqhele yesikhashana ihlala amasonto kuya ezinyangeni ngaphansi kokusebenza okugcwele. Amazinyo okufakelwa enziwe nge-PMMA amelana neminyaka yokusetshenziswa ngaphambi kokubonisa ukuguguleka okukhulu.
Lokho kusho ukuthi, "okuqinile" kuncike kumongo. I-PMMA isebenza kahle kakhulu ekusetshenzisweni lapho kungalindelekile ukuthi ithwale umthwalo ogcwele, wesikhathi eside wokulungiswa kwangemuva okuhlala njalo ku-bruxer esindayo. Kulezo zimo, ezinye izindlela ezifana ne-zirconia zinengqondo kakhulu. Kwezinye izimo eziningi zokusetshenziswa, amandla e-PMMA anele kakhulu - futhi izindleko eziphansi ngeyunithi ngayinye ziba yinzuzo enkulu ngezinga.
I-Aesthetics yilapho i-PMMA ihlala ikhiqiza ngokweqile uma kuqhathaniswa nentengo yayo. Ukukhanya kwayo kuhambisana kakhulu ne-enamel yemvelo, futhi itholakala ezinhlobonhlobo zemibala engafaniswa ngqo namazinyo azungezile. Iyacwebezela ibe nombala ocwebezelayo ohlala isikhathi eside.
Ngamazinyo esikhashana angaphambili namazinyo okufakelwa, iziguli zivame ukungakwazi ukuhlukanisa i-PMMA ezintweni ezibiza kakhulu. Lelo iqiniso elibalulekile ngokwezokwelapha nangokwezentengiselwano kuma-lab akhonza izimakethe eziqaphela izindleko.
I-PMMA iyathethelela ukusebenza nayo. Isebenza ngendlela ebikezelwayo emisebenzini ye-CAD/CAM, ilungisa kalula eceleni kwesihlalo, futhi ilungisa ngokushesha. Kumalebhu anevolumu ephezulu, lokhu kuhunyushwa ngqo ekusetshenzisweni. Izikhathi zokucubungula ezisheshayo, ukwenziwa kabusha okumbalwa, kanye nokufakwa okulula kusho izindleko zokukhiqiza eziphansi - inzuzo ehlanganiswa nama-oda amakhulu.
Ukudumazeka okuvame kakhulu nge-PMMA kuvela ekusetshenzisweni kwayo endaweni engafanele. Ukuhuzuka kwendawo kungumkhawulo wayo oyinhloko ngokuhamba kwesikhathi - ezindaweni ezigugile kakhulu, indawo ingaba buthuntu noma ikhiqize imihuzuko emincane ethinta ubuhle. Lokhu kungalawuleka ngokupholisha njalo kodwa kufanelekile ukucatshangelwa ezimisweni zokuxhumana neziguli kanye nokugcinwa kwazo.
I-PMMA nayo inamandla aphansi okugoba kune-zirconia noma i-lithium disilicate. Kuziguli ezinamandla okuluma aqinile noma imikhuba ye-parafunctional, lokhu kubalulekile. Ukusebenzisa i-PMMA ekubuyiseleni ingemuva unomphela kulezi ziguli cishe kungabangela ukwehluleka kwangaphambi kwesikhathi kanye nezindleko ezihambisanayo zokufaka esikhundleni.
Imikhawulo emithathu okufanele uyikhumbule:
• Ukuguguleka kwendawo ngokuhamba kwesikhathi: Kubaluleke kakhulu kumabhuloho amade kanye namakesi anomthwalo omningi.
• Akufanelekile ukulungiswa okuhlala njalo okunamandla amakhulu: Kulungele kangcono izinhlelo zokusebenza ezihlala njalo zesikhashana noma ezidinga kakhulu.
• Ukuthambekela ekuqhekekeni ngaphansi kokucindezeleka okuqhubekayo: Akuvamile, kodwa kuyingozi ekulungisweni okungasebenzi kahle noma okuncane kakhulu.
I-ceramics — ikakhulukazi i-zirconia ne-lithium disilicate — isebenza kahle kakhulu kune-PMMA ngamandla kanye nokumelana nokuguguleka kwesikhathi eside. Yiyona ndlela ekhethwayo yokufuna ukulungiswa okuhlala njalo. I-PMMA, ngakolunye uhlangothi, iwina ngezindleko, isivinini sokwenziwa, ukulula kokulungiswa, kanye nokuguquguquka kobuhle ngentengo.
Isifundo esiwusizo: lezi zinto azincintisani ezimweni eziningi zezokwelapha. Zisebenza imisebenzi ehlukene. Amalebhu agcina kokubili futhi aqondayo ukuthi kufanele asetshenziswe nini ngalinye akhiqiza imiphumela engcono njalo kunalawo azinikele ezintweni ezilodwa kuzo zonke izimo.
Imiqhele yesikhashana yilapho i-PMMA ibusa khona. Yenziwa ngokushesha kusetshenziswa i-CAD/CAM milling, ingena kahle, ibukeka kahle, futhi ivikela izinyo elilungisiwe ngenkathi kulungiswa unomphela. Kuma-lab asebenzisa izinhlelo zokugaya zesimanje, amazinga okushisa e-PMMA angakhiqizwa ngemizuzu ngemiphumela ehambisanayo nebikezelwayo.
Ikhwalithi yesikhashana sokugcina incike kakhulu ezintweni ezimbili: ikhwalithi yebhulokhi ye-PMMA kanye nokunemba kwemishini yokugaya. Izinto ezingaphansi kwekhwalithi noma umshini wokugaya ongalingani kahle ukhiqiza imingcele engavali, izindawo eziqinile, kanye nezikhathi zesikhashana ezidinga ukulungiswa njalo. Ukwenza kokubili kube okulungile kususa izikhalazo eziningi ezivamile mayelana nezikhathi zesikhashana ze-PMMA.
I-PMMA ibilokhu iyindwangu ejwayelekile yezisekelo zamazinyo okufakelwa iminyaka engaphezu kwengu-70 — futhi ngesizathu esihle. Ilula, okubalulekile ukuze isiguli siduduzeke phakathi nosuku lonke lokugqoka. Inombala olula ukuze ifane nezicubu zesisu. Iqinile ngokwanele ukuthi ingasinda ekuweni okuncane nasekusetshenzisweni kwansuku zonke. Futhi ingalungiswa futhi ilungiswe eceleni kwesihlalo ngaphandle kwemishini ekhethekile.
Amazinyo okufakelwa e-PMMA anamuhla anikeza iphrofayili yomthunzi kanye nokukhanya okufana kakhulu namazinyo emvelo. Uma ehlanganiswe nesisekelo esilungiselelwe kahle, amazinyo okufakelwa e-PMMA ahlala eyisisombululo esiwusizo kakhulu nesingabizi kakhulu kubantu abaningi abagulayo abangakwazi ukuhlinzwa.
Ekwelashweni kwamazinyo okufakelwayo, ukulungiswa kwesikhashana kudlala indima ebalulekile ngesikhathi sokuhlanganiswa kwe-osseo. Kudingeka kuvikele indawo yokuhlinzwa, kugcinwe ubuhle, kuqondise ukuphulukiswa kwezicubu ezithambile, futhi kusebenze ngaphansi kwemithwalo yangempela ye-occlusal - konke lokhu kube lula ukukulungisa njengoba ukuphulukiswa kuqhubeka.
I-PMMA ifaneleka kahle kule ndima. Ingakhiwa ngokushesha ngaphambi noma ngokushesha ngemva kokuhlinzwa, ilungiswe kalula njengoba imigqa yezicubu ishintsha, futhi ishintshwe ngaphandle kobunzima uma i-implant isihlanganiswe ngokuphelele. Izindleko zayo eziphansi zenza kube wusizo ukufaka esikhundleni sesikhashana izikhathi eziningi ngesikhathi sokuphulukiswa isikhathi eside ngaphandle kwezindleko ezinkulu.
Iphuzu elilodwa okufanele liqashelwe ekuthengweni: ukunemba kokugaya okudingekayo kwesikhashana sokufakelwa kuphakeme kunesikhathi esijwayelekile. Ukulingana esibonakalayo sokufakelwa kuthinta ngqo impilo yezicubu kanye nemiphumela yokuhlanganiswa. Lena indawo lapho ikhwalithi yezinto ze-PMMA kanye nemishini yokugaya kuyizinto ezibalulekile.
I-PMMA yeminyaka emihlanu edlule akuyona i-PMMA etholakalayo namuhla. Abakhiqizi baqhubeka nokuthuthukisa ukwakheka: izingxube ezinamandla aphezulu, amabhlogo amaningi ane-gradient yomthunzi eyakhelwe ngaphakathi, izinhlobo zokulwa namagciwane ezinciphisa ukunamathela kwamagciwane, kanye nezinto ezithuthukisiwe ze-nanotechnology ezithuthukisa kokubili ubuhle kanye nokumelana nokuguguleka.
Lezi ntuthuko zifiphaza kancane kancane umugqa phakathi "kwesikhashana" kanye "nokuphakade" endimeni yezokwelapha ye-PMMA. Ezinye izindlela ezintsha ze-PMMA ezinamandla aphezulu sezivele zisetshenziselwa ukuvuselelwa okuhlala isikhathi esifushane kuya kwesiphakathi ezimweni ezifanele - umkhuba cishe ozoqhubeka njengoba isayensi yezinto ezibonakalayo iqhubeka.
Kuhle ukukhuluma ngokuqondile ngento evame ukunganakwa ezingxoxweni zezinto ezibonakalayo: ikhwalithi yokubuyiselwa kwe-PMMA inqunywa kancane yizinto ezibonakalayo. Inqubo yokugaya ibaluleke ngokulinganayo.
Ibhulokhi elihle kakhulu le-PMMA eligaywe emishinini engalingani kahle noma esidala lizokhiqiza imiphumela engemihle — izindawo ezimagebhugebhu, ukulingana okungekuhle, izinto ezilahliwe. Ngokuphambene nalokho, ibhulokhi le-PMMA eliphakathi nendawo eligaywe ohlelweni olunakekelwe kahle, olulinganiswe kahle lingakhiqiza ukulungiswa okungaphezu kokusebenza kwezokwelapha kwezinto ezibizayo ezicutshungulwa emishinini engemihle.
Kumalebhu nakubathengi abahlola izindleko zabo zokukhiqiza, imishini yokugaya iyisiguquguquki esinamandla aphezulu kakhulu. Imishini yokugaya efanele inciphisa imfucuza yezinto ezibonakalayo, yandisa umkhiqizo, futhi ithuthukisa ukuhambisana kuzo zonke izimo — i-PMMA noma enye indlela.
Amalebhu amazinyo ahamba phambili asebenza kabanzi njengezindawo ezihlanganisiwe: ukuhlanganisa imisebenzi yokuklama yedijithali nokugaya okunembe kakhulu, kusetshenziswa i-PMMA nezinye izinto ngokushelela ngokusekelwe ezidingweni zecala. Ukuhlanganiswa kwe-CAD/CAM, ukugaya okuzenzakalelayo, kanye nokuklama okusizwa yi-AI kunciphisa izikhathi zokukhiqiza kanye namaphutha omuntu ngasikhathi sinye.
Kwabasabalalisi kanye namaqembu okuthenga, lolu shintsho lunemiphumela engokoqobo. Amalebhu atshala imali emisebenzini yedijithali adinga izinto zokwakha kanye nemishini ehambisana nalezo zinhlelo. Izinqumo zokuthola izinto ezenziwe namuhla zidinga ukubheka ukuthi imboni iyaphi, hhayi nje isidingo samanje.
Izinto zamazinyo ze-PMMA zisesikhundleni esibalulekile nesihlala njalo ochungechungeni lokuhlinzekwa kwamazinyo — hhayi ngenxa yokungakhathali, kodwa ngoba ziyaqhubeka nokuletha inani langempela lezokwelapha nezomnotho. Ziyakwazi ukushintshashintsha, ziyaqondakala kahle, futhi ziyathuthuka minyaka yonke.
Amaqiniso amahlanu abaluleke kakhulu kubathengi nabasabalalisi: Izakhiwo ze-PMMA zingenziwa ngokwezifiso futhi azikwazi ukushintshaniswa kuyo yonke imikhiqizo; izinzuzo zayo ekubukekeni, ekuphatheni, kanye nezindleko zingokoqobo futhi ziyalinganiswa; ukulinganiselwa kwayo kuyabikezelwa futhi kuyalawuleka ngokukhethwa okufanele kwecala; izindima zayo ezintathu zezokwelapha ngayinye inezidingo zokusebenza ezihlukile; futhi ikusasa le-PMMA lixhumene kakhulu nobuchwepheshe bokugaya bedijithali.
Ukuqonda ngokujulile lokhu okuqukethwe yikona okwenza ukuthenga kube okuhlakaniphile, kube nokubuyiselwa okuncane, kanye nobudlelwano obuqinile nama-lab kanye nemitholampilo oyinikezayo.
Ukuze ivule ngokugcwele amandla e-PMMA, uhlelo lokugaya lubaluleke kakhulu njengezinto ezibonakalayo. I-Dentex iklama imishini yokugaya enembile ye-CAD/CAM eyakhelwe ngqo amalebhu wamazinyo adinga ukuhambisana, isivinini, kanye nokunemba kukho konke ukuvuselelwa. Funda kabanzi mayelana nezixazululo zokugaya ze-Dentex →