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Dr. Clarence Tam, HBSC, DDS, AAACD, FIADFE

Porcelāna venīru izmantošana, lai uzlabotu un atjaunotu priekšējo zobu formu, toni un vizuālo stāvokli, ir izplatīta tehnika estētiskajā zobārstniecībā. Biomimētiskais mērķis zobu restaurācijā ir ne tikai kosmētikas joma, bet arī funkcionālie apsvērumi. Ir svarīgi atzīmēt, ka aukslēju un vaiga sieniņu neskartais emaljas apvalks attiecībā pret priekšējiem zobiem ir atbildīgs par tā iedzimto lieces pretestību. Ja zobu struktūra ir bojāta endodontiskas piekļuves, kariesa un/vai traumas dēļ, ir jādara viss iespējamais, lai saglabātu atlikušo struktūru un jācenšas atjaunot vai pārsniegt neapstrādāta zoba sākotnējo veiktspējas līmeni.

PAMATINFORMĀCIJA

55 gadus veca ASA II sieviete uz zobu balināšanu. Bija paredzēts, ka zobu balināšana neietekmēs jau esošā porcelāna zoba 1.2 venīra toni. Tas būtu jāapstrādā pēc procedūras, it īpaši, ja toņa vērtības izmaiņas būtu būtiskas. Pacientes sākotnējais tonis bija VITA* 1M1:2M1; 50:50 attiecībā augšējā priekšējā reģionā un 1M1 apakšējā priekšējā reģionā. Pēc nakts kapju balināšanas protokola ar 10% karbamīda peroksīdu, kas tika nēsātas naktī 3-4 nedēļas, pacientei izdevās panākt VITA* 0M3 toni gan augšējā, gan apakšējā arkā. Rezultātā radās ievērojama vērtību neatbilstība starp zoba 1.2 venīru un blakus esošajiem zobiem, un tika novērota palielināta hroma uz kontralaterālā zoba 2.2, ko izraisīja ar seju saistīta III klases kompozīta restaurācija. Šis pēdējais zobs arī pēc izmēra nesakrita ar kontralaterālo zobu, un tāpēc tika pieņemts lēmums abus sānu priekšzobus apstrādāt ar saistītiem litija disilikāta lamināta venīriem. Blakus esošajam acu zobam (2.3) bija lokalizēts viegls līdz vidējs smailes galu nodilums, taču kamēr netika uzlikti pašlaik apspriestie venīri. Smaida dizaina mērķis šajā posmā ir izveidot divpusēju harmoniju, lai tuvākajā laikā veiktu papildu netiešo restaurāciju, kas atjaunotu 2.3 zoba sejas formu un smailes galu deficītu.

PROCEDŪRA

Sākotnējai iecerei, kas bija individuāla sānu priekšzobu apstrāde, digitālais smaida dizaina protokols nebija nepieciešams. Šim zobu tipam ir pieļaujamas nelielas variācijas, kas ir smaida personības un dzimuma marķieris. Pirms anestēzijas mērķa toni izvēlējās, izmantojot fotogrāfijas, kurās bija gan polarizēta, gan nepolarizēta atlase. Fotogrāfijas tika sagatavotas digitālai toņa kalibrēšanai, uzņemot atsauces skatus ar 18% neitrāla pelēkā baltā balansa karti (1. attēls).

1. attēls. Atsauces fotogrāfija, kas uzņemta ar 18% neitrālu pelēko karti.

Pamata nokrāsa bija VITA* 0M2 ar lietņa toni BL2. Paciente tika anestēzēta, izmantojot 1,5 karpulas 2% lignokaīna šķīduma ar 1:100 000 epinefrīnu, pirms tika piestiprināts gumijas aizsargs sadalītā aizsarga orientācijā. Zoba 1.2 venīrs tika sadalīts un noņemts no zoba 1.2, un tika pabeigta minimāli invazīva venīrs sagatavošana uz zoba 2.2 (2. attēls). Daļēja vecās kompozītmateriāla sveķu restaurācijas nomaiņa tika pabeigta 12. zoba mesioincisobukopalatālajā aspektā, saglabājot neskartu segmentu. Saķere ar veco kompozītmateriālu tika panākta, izmantojot gan mikrodaļiņu abrāziju, gan silāna savienojošo līdzekli (CLEARFIL™ CERAMIC PRIMER PLUS). Piemales tika uzlabotas, un ievilkšanas auklas iemērktas alumīnija hlorīda šķīdumā un iepildītas. Tika reģistrēti sagatavošanas celmu toņi. Galīgie nospiedumi tika ņemti, izmantojot gan vieglo, gan smago polivinilsiloksānu metāla paplātē. Pacientei tika veikta pagaidu apstrāde, un viņa tika nosūtīta ar instrukcijām pārbaudīt toni laboratorijā apdedzināšanas stadijā. Laboratorijas sagatavotie modeļi pārbauda gadījuma minimāli invazīvo raksturu.

2. attēls. Venīra sagatavošana zobam 1.2, 2.2

Pēc gadījuma saņemšanas paciente tika anestēzēta un izņemts provizoriskais līdzeklis. Preparāti tika attīrīti un sagatavoti savienošanai, nopulējot virsmas, izmantojot 27 mikronu alumīnija oksīda pulveri ar 30–40 psi. Venīri tika novērtēti, izmantojot caurspīdīgu glicerīna pastu (PANAVIA™ V5 Try-in Paste Clear, Kuraray Noritake Dental Inc.). Ievilkšanas auklas tika iepildītas un restaurāciju dziļspieduma virsma apstrādāta, izmantojot 5% fluorūdeņražskābi 20 sekundes pirms 10-MDP saturoša silāna savienojošā līdzekļa (CLEARFIL™ CERAMIC PRIMER PLUS, (3. attēls)) uzklāšanas. Zoba virsma 20 sekundes tika kodināta ar 33% ortofosforskābi un noskalota. Uz zoba tika uzklāts 10-MDP saturošs gruntējums (PANAVIA™ V5 Tooth Primer (4. attēls). un nožāvēts gaisā saskaņā ar ražotāja norādījumiem. Tika ievietots venīra cements (PANAVIA™ Veneer LC Paste Clear) (5. attēls) un uzlikts venīrs. Cementa pārpalikums nebija slīdošs, un tas labi noturēja venīru visu piemaļu pārbaužu laikā pirms 1 sekundes sacietēšanas (6. attēls).

3. attēls. CLEARFIL™ CERAMIC PRIMER PLUS uzklāts uz venīra dziļspieduma virsmām.

4. attēls. PANAVIA™ V5 Tooth Primer uzklāšana uz kodinātām zobu virsmām.

5. attēls. PANAVIA™ Veneer LC Paste Clear tonis, kas tiek uzklāts uz sagatavotām dziļspieduma venīra virsmām.

6. attēls. PANAVIA™ Veneer LC Paste uzreiz pēc uzlikšanas. Ņemiet vērā cementa viskozo, neslīdošo raksturu, kas ļauj viegli noņemt gan mitrā, gan gēla fāzē.

Cements tika pārveidots gēla stāvoklī, kas atviegloja cementa pārpalikumu noņemšanu ar minimālu tīrīšanu (7. attēls). Pirms galīgās cietināšanas piemales tika pārklātas, izmantojot caurspīdīgu glicerīna gēlu, lai likvidētu skābekļa inhibīcijas slāni (8. attēls).

7. attēls. Liekā cementa noņemšana pēc 1 sekundes cietināšanas.

8. attēls. Venīra galīgā cietināšana vienlaicīgi no palatālā un sejas aspekta.

Piemales tika pabeigtas un pulētas līdz spīdumam, un restaurāciju oklūzija tika apstiprināta kā atbilstoša. Pēcoperācijas skati parāda izcilu estētisko marginālo integrāciju (9. attēls).

9. attēls. Pēcoperācijas estētiskā venīra integrācija uz zoba 1.2 un 2.2.

Novērtējot polarizēto fotogrāfiju, restaurācijas estētiski un funkcionāli ir labi integrētas jaunajā smaidā (10. attēls), tagad tiek gaidīta estētiskā zoba 2.3 augmentācija, lai tas atbilstu kontralaterālajam acu zobam.

GALA REZULTĀTS

10. attēls. Gala rezultāts ar polarizētu fotogrāfiju, veicot atkārtotu novērtēšanu

Dentist:

CLARENCE TAM

References

1. Magne P, Douglas WH. Rationalization of esthetic restorative dentistry based on biomimetics. J Esthet Dent. 1999;11(1):5-15. doi: 10.1111/j.1708-8240.1999.tb00371.x. PMID: 10337285.
2. Magne P, Douglas WH. Porcelain veneers: dentin bonding optimization and biomimetic recovery of the crown. Int J Prosthodont. 1999 Mar-Apr;12(2):111-21. PMID: 10371912.
3. Pongprueksa P, Kuphasuk W, Senawongse P. The elastic moduli across various types of resin/dentin interfaces. Dent Mater. 2008 Aug;24(8):1102-6. doi: 10.1016/j.dental.2007.12.008. Epub 2008 Mar 4. PMID: 18304626.
4. Source: Kuraray Noritake Dental Inc. Samples (beam shape; 25 x 2 x 2 mm): The solvents of each material were removed by blowing mild air prior to the test.

Augstas kvalitātes protezēšanas nozīme

Augstas kvalitātes ārstēšana, iespējams, ir vissvarīgākais faktors ceļā uz pacienta apmierinātību. Katrā vizītē pacients vēlas justies kvalificēta speciālista aprūpēts. Savukārt krēslā pavadītais laiks un vizīšu skaits ir jāsamazina līdz nepieciešamajam minimumam. Tas nozīmē, ka protezēšanas kontekstā restaurācijai nekavējoties ir perfekti jāpieguļ un laika gaitā tai jābūt stabilai, lai izvairītos no pārtaisīšanas un papildus apmeklējumiem.

Bet kā iespējams katru reizi nodrošināt perfekti pieguļošas, kvalitatīvas restaurācijas? Starp potenciālajiem netiešo restaurāciju kvalitātes problēmu avotiem var minēt bieži pieļautās kļūdas zobārstniecības kabinetā vai laboratorijā, komunikācijas problēmas un bieži vien zemas kvalitātes zobu cirkonija oksīda izmantošanu.

Cirkonija restaurācijas – mūsdienīgs un estētisks zobārstniecības risinājums

Vairāk nekā pirms 20 gadiem cirkonija oksīds ienāca zobārstniecības tirgū kā kroņu un tiltu ražošanā izmantotā metāla aizstājējs. Abi materiāli – gan cirkonija oksīds, gan metāls – parasti tika apvienoti ar porcelāna slāni, veidojot porcelāna, metālā izkausēta porcelāna vai cirkonijā izkausēta porcelāna restaurācijas. Turpmākajos gados vairāki vadošie zobārstniecības cirkonija oksīda ražotāji (piemēram, Kuraray Noritake Dental Inc.) koncentrējās uz materiāla uzlabojumiem. Šie uzlabojumi pakāpeniski pārveidoja sākotnējo balti necaurspīdīgo karkasa materiālu keramikas materiālā ar zobiem līdzīgām optiskajām un izcilām mehāniskajām īpašībām. Daudzi zobārstniecības speciālisti visā pasaulē uzskata jaunākos cirkonija oksīda variantus, kas pieejami ar dažādiem caurspīdīguma un stiprības līmeņiem, par labāko iespējamo ārstēšanas iespēju dažādiem pacientiem un indikācijām. Viens no iemesliem ir tas, ka tiem ir nepieciešams tikai neliels porcelāna slānis, vai vispār nav vajadzīgs. Cits iemesls ir tas, ka ar mazu minimālo sieniņu biezumu tie ļauj veikt konservatīvu zobu sagatavošanu, vienlaikus nodrošinot labvēlīgu ilgtermiņa kalpošanu – ar noteikumu, ka tiek izmantots augstas kvalitātes materiāls.

Zobu cirkonija kvalitātes atšķirības

Cirkonija produktu kvalitāte var atšķirties atkarībā no dažādiem faktoriem, piemēram, izejvielu tīrības (ne tikai cirkonija, bet arī alumīnija oksīda un itrija, kā arī krāsvielu piedevu utt.), precīza ķīmiskā sastāva, daļiņu izmēra un sadalījuma. Katrs solis sagatavju ražošanas procesā – no pulvera sagatavošanas līdz sagatavju presēšanai un sinterizācijai sastiprināšanai – ietekmē gala kvalitāti, t.i., arī cirkonija mehāniskās un optiskās īpašības.

Bieži sastopamās problēmas, ko izraisa zemas kvalitātes cirkonija oksīds

Ikreiz, kad kaut kas nav kārtībā ar restaurācijas optiskajām īpašībām – ar tās caurspīdīgumu, kopējo krāsu vai pāreju no viena slāņa uz nākamo sagatavēs ar daudzslāņu krāsu struktūru – problēma kļūs acīmredzama pēc sinterizācijas laboratorijā. Rezultātā var būt nepieciešamība pārtaisīt, kā arī defekts var tikt atklāts laikošanas laikā, kas, visticamāk, negatīvi ietekmēs pacienta apmierinātību. Tas pats attiecas uz gadījumiem, kad, piemēram, materiāla struktūras neviendabīgums izraisa neprecīzu piegulēšanu. Vēl sliktāk ir zemākas pakāpes bioloģiskā saderība, virsmas kvalitāte, malu stabilitāte, lieces stiprība vai izturība pret lūzumiem. Šīs problēmas var identificēt tikai ar testēšanas aprīkojumu, kas ir ļoti dārgs un parasti nav pieejams zobārstniecības laboratorijās. Tas nozīmē, ka šāda veida nepilnības parasti paliek neatklātas līdz rodas reāla klīniska problēma, piemēram, smaganu recesija, palielināta aplikuma uzkrāšanās, lielāks nodilums vai agrīns defekts, kas var izraisīt sāpes un diskomfortu.

Overview of potential problems and clinical consequences for patients

Zobu cirkonija sertifikācija un standartizācija

Speciālisti ir izstrādājuši ISO standartu (ISO 6872:2015), kurā aprakstīti in vitro testi, kas jāveic katram Eiropā vai ASV izmantotā zobārstniecības cirkonija ražotājam, lai saņemtu FDA apstiprinājumu un CE marķējumu. Aprakstītie testi tiek izmantoti, lai izmērītu lieces stiprību un izturību pret lūzumiem, kas, iespējams, ir divas vissvarīgākās īpašības, kas nosaka no materiāla izgatavoto restaurāciju ilglaicīgu darbību. Katram Eiropā vai Amerikas Savienotajās Valstīs izmantotajam materiālam ir jānokārto šie testi.

Kā izvairīties no zemas kvalitātes zobu cirkonija restaurāciju ievietošanas pacienta mutē

Ikvienam, kas izmanto šo sertificēto zobu cirkoniju, jābūt pārliecinātam un jāspēj samazināt ar materiāliem saistītos riskus. Tomēr zobu cirkonija pieaugošā popularitāte ir piesaistījusi to uzņēmumu uzmanību, kuri cenšas iegūt savu kumosa daļu, neveicot nepieciešamos pasākumus, lai nodrošinātu augstu produkta kvalitāti un nokārtotu sertifikāciju. Nesertificētiem produktiem, kuriem nav CE marķējuma, ir viena kopīga iezīme: tie noteikti rada draudus Jūsu uzņēmumam un pacientiem.

Ņemot vērā augstāk aprakstīto kā ir iespējams nodrošināt cirkonija produktu kvalitāti zobārstniecībā? Labā ziņa ir tāda, ka ir pieejami daži vienkārši noteikumi. Ievērojot tos, jūs varat izvairīties no viltotu vai zemas kvalitātes zobu cirkonija restaurāciju ievietošanas pacienta mutē.

Izvairieties no viltotu vai zemas kvalittes zobu cirkonija restaurciju ievietoanas pacienta mutē.

Trīs zelta likumi, lai nodrošinātu saviem pacientiem augstas kvalitātes cirkonija restaurācijas:

• Pasūtiet tikai tādas restaurācijas, kas ražotas vietējā tirgū vai reģionā ar tādiem pašiem standartiem kā jums: piemēram, Ķīnas zobārstniecības laboratorijās ražotām restaurācijām ir jāatbilst zemākiem standartiem (tātad tām nav CE marķējuma), un tās var neatbilst jūsu cerībām.
• Konsultējieties ar savu (vietējo) laboratoriju par viņu cirkonija oksīda ražotāju, pārliecinieties, vai viņi iegādājas cirkoniju no vadošajiem ražotājiem (piem., Kuraray Noritake Dental Inc.), izmantojot pilnvarotus izplatītājus vai pārdevējus, kurus viņi pazīst.
• Izvairieties no piedāvājumiem, kas ir pārāk labi, lai būtu patiesi: zemas cenas var būt vilinošas, taču ārstēšanas galīgās izmaksas var būt pat augstākas nekā parasti, ja rodas komplikācijas.

Ilgtermiņa ietekme pacientiem, izmantojot sertificētas cirkonija restaurācijas

Pārliecība, ka jūsu zobārstniecības kabinetā izmantotais cirkonijs atbilst augstākajiem iespējamajiem kvalitātes standartiem, ir svarīgs ieguldījums pacientu ilgtermiņa apmierinātībā. Pat ja augstas kvalitātes cirkonija restaurācijas sākotnējās izmaksas ir nedaudz augstākas nekā zemākas kvalitātes darba izmaksas, kopējais ieguldījums var būt mazāks, ja restaurācija kalpo ilgāk un tiek novērsta pārtaisīšana. Jūsu apmierinātie pacienti, visticamāk, būs vairāk iesaistīti un ievēros mutes higiēnu, kā arī būs lojāli, tādējādi pozitīvi ietekmējot jūsu reputāciju un pacientu bāzi.

Izpētiet cirkonija iespējas un izvēlieties produktus no sertificētiem ražotājiem

Ja vēlaties spert soli tālāk, varat pat salīdzināt vairāku ražotāju sertificētos cirkonija variantus un atklāt atšķirības. Piemēram, Kuraray Noritake Dental Inc. ir viens no nedaudzajiem zobu cirkonija mražotājiem, kas veic visu ražošanas procesu, tostarp izejvielu ražošanu uz vietas. Tādā veidā uzņēmums spēj kontrolēt katru procedūras soli un nodrošināt izcilu produkta kvalitāti – neatkarīgi no tā, kurš materiāla variants tiek izvēlēts. Ar pieejamo sortimentu, kas sastāv no KATANA™ Zirconia UTML (īpaši caurspīdīgs daudzslāņu), KATANA™ Zirconia STML (izcili caurspīdīgs daudzslāņu) un ļoti caurspīdīga daudzslāņu HTML PLUS, kā arī YML (ar papildu stiprības un caurspīdīguma gradāciju), ir iespējams aptvert praktiski visas indikācijas.

PROF. LORENCO BREŠI (LORENZO BRESCHI) RAKSTS

Mazāk pudeļu, vairāk izvēles – tas, iespējams, ir īsākais veids, kā aprakstīt universālo sveķu cementu kategoriju. Šie divkāršās cietēšanas sveķu cementi, kas ir pašlīmējoši, nodrošina vienkomponenta darbplūsmu, daudzās klīniskās situācijās neizmantojot atsevišķus zobu vai restaurācijas praimerus. Šādā veidā iegūtā saķeres stiprība parasti ir pietiekami augsta, lai nodrošinātu stabilu saķeri starp zobu un restaurāciju plašā indikāciju diapazonā. Tomēr tā ir nedaudz zemāka nekā tā, kas tiek sasniegta ar parastajām sveķu cementa sistēmām, kas sastāv no vairākiem komponentiem (parasti zobu saite sveķu cements un restaurācijas saite).

Papildus pašlīmējošajam uzklāšanas veidam universālos sveķu cementus var kombinēt ar papildu sistēmas sastāvdaļām, lai attiecīgi palielinātu saķeres stiprību ar zoba struktūru vai restaurācijas materiālu. Tas paver jaunas iespējas produkta lietošanā: atkarībā no nepieciešamās vai vēlamās saķeres veiktspējas universālo sveķu cementu var uzklāt atsevišķi vai kombinācijā ar zobu saiti restaurācijas saiti vai abām sastāvdaļām. Turklāt hibrīda koncepcijas kļūst iespējamas, kā paskaidrots šajā rakstā, kurā galvenā uzmanība pievērsta PANAVIA™ SA Cement Universal (Kuraray Noritake Dental Inc.) kā piemēram.

Pašcementējošā fiksācija: daudzām indikācijām

PANAVIA™ SA Cement Universal ir divējādi cietējošs universāls sveķu cements, kas ir paredzēts plašam pielietojumu klāstam, ja to izmanto pašcementējošā veidā. Saķere, kas izveidota ar restaurācijas substrātiem (tostarp silikāta keramiku), ir spēcīga, neizmantojot atsevišķu saiti vai silānu1-4. Tas ir saistīts ar diviem dažādiem lipīgajiem monomēriem, ko satur preparāts – oriģinālais MDP monomērs un LCSi monomērs (garas oglekļa ķēdes silāna savienošanas līdzeklis, kas atbild par spēcīgu ķīmisko saiti ar silikāta keramiku). Tādējādi ir iespējams izmantot sveķu cementu bez papildu komponentiem, kas tiek uzklāti uz restaurācijas sāniem – pat gadījumos, kad trūkst saķeres un līdz ar to ir augstas prasības attiecībā uz saķeres stiprību.

Spēcīga saķere ar emalju un dentīnu tiek iegūta arī pašlīmējošā veidā. Tomēr dažās situācijās var būt lietderīgi vēl vairāk palielināt saķeres stiprību ar zoba struktūru, izmantojot zobu saiti.

Adhezīva līmēšana: sarežģītām situācijām

PANAVIA™ SA Cement Universal ieteicamā zobu saite ir CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.). Tā lietošana ir ieteicama ikreiz, kad lietotājs uzskata, ka ārstēšanai noderētu īpaši spēcīga un izturīga ķīmiskā saite, t.i., īpaši sarežģītās situācijās ar nepietiekamu mehānisko noturību. Šī pasākuma efektivitāte ir apstiprināta Japānā veiktā in vitro pētījumā, kurā 24 stundu mikro stiepes saites stiprība pret dentīnu tika ievērojami palielināta, uzklājot universālo cementu5. Izmantojot atsevišķu cementu pieaug pilnīgi sausa darba lauka nozīme. Iemesls ir tāds, ka sveķu cementa mitruma tolerance parasti ir augstāka nekā cementiem. Līdz ar to koferdama uzlikšana ir ļoti ieteicama.

Selektīva adhezīva cementēšana: īsiem noslīpētiem zobiem un subgingivālajām malām

Situācijās, kad ir grūti pareizi izolēt darba lauku ar koferdamu ir pieejama trešā uzklāšanas iespēja, ko piedāvā Itālijas pētnieku grupa: selektīva adhezīva fi ksācija. Šajā gadījumā CLEARFIL™ Universal Bond Quick tiek uzklāts tikai uz tām sagatavotā zoba daļām, kas nodrošina pareizu mitruma kontroli, vienlaikus paļaujoties uz PANAVIA™ SA Cement Universal pašcementējošo funkcionalitāti vietās, kur ir grūti iegūt vēlamo sauso darba lauku. Situācijas, kas ir paredzētas šai tehnikai, ir slīpēti zobi ar subgingivālu sagatavošanu un īpaši īsi slīpēti zobi (kas kavē koferdama novietošanu).

Selektīvās adhezīva fiksācijas tehnikas efektivitāte ir pārbaudīta in vitro pētījumā, kurā tika salīdzinātas trīs līmēšanas stratēģijas – pašcementējošā fiksācija pilnībā adhezīva fiksācija un selektīva adhezīva fiksācija – ar bīdes saišu stiprības pārbaudes palīdzību6. Pārbaužu rezultāti liecina, ka lietotāji var uzlabot PANAVIA™ SA Cement Universal saķeres stiprību ar dentīnu un emalju, uzklājot cementu tikai uz zoba virsmas daļas. Cementēšanas sistēmai, kas sastāv no PANAVIA™ SA Cement Universal un CLEARFIL™ Universal Bond Quick, pilnībā adhezīva un selektīvā adhezīva pieeja radīja līdzīgus rezultātus.

Situācij ās, kad ir grūti pareizi izolēt darba lauku ar koferdamu ir pieejama trešā uzklāšanas metode ko piedāvā Itālij as pētnieku grupa: selektīva adhezīva fiksācija

Rekomendētās darbības selektīvajai adhezīva līmēšanai

1. attēls. Zoba sagatavošana

2. attēls. Selektiva emaljas kodinašana ar fosforskabes kodinataju

3. attēls. Universala adheziva uzklašana un žavešana ar gaisu

4. attēls. Krona novietošana pec sveku cementa uzklašanas kroni

5. attēls. Cietinašana

6. attēls. Lieka daudzuma noemšana un galeja cietinašana
gaisma

7. attēls. Arstešanas rezultats pec viena gada

Selektīvās adhezīva cementēšanas priekšrocības

Papildus vēlamajam (ilgtermiņa) saķeres stiprības pieaugumam, kas tiek panākts, uzklājot atsevišķu cementu uz daļas vai visas sagatavotās zoba virsmas, tehnika piedāvā papildu priekšrocības. Salīdzinot ar daudzpakāpju cementēšanas sistēmām, protokols ir vienkāršots, jo nav nepieciešams atsevišķa restaurācijas saite. Cementa cietināšana gaismā nav nepieciešama, kamēr lietotājs paliek ieteiktajā sistēmā. Un atšķirībā no pilnībā adhezīvas pieejas, kurā ir nepieciešams uzstādīt koferdamu šī soļa nepieciešamība ir izslēgta, izmantojot selektīvo adhezīva pieeju. Tādā veidā tiek samazināts krēslā pavadītais laiks un palielināts pacienta komforts.

Secinājumi

Atkarībā no indikācijas, klīniskajiem mainīgajiem lielumiem un individuālajām vēlmēm, universālo sveķu cementa, piemēram, PANAVIA™ SA Cement Universal, lietotāji var izvēlēties tehniku, kas, visticamāk, nodrošinās vislabākos klīniskos rezultātus. Tieši šī elastība un kopumā plašais pielietojumu klāsts padara inovatīvo produktu kategoriju patiesi universālu. Tā kā izmantojamo komponentu skaits ir mazāks, universālie materiāli atvieglo klīnisko procedūru racionalizāciju un standartizāciju, savukārt ar mazāku uzglabājamo pudeļu skaitu tas palīdz darbiniekiem iegūt kontroli pār pasūtījumu un uzglabāšanas pārvaldību.

Dentist:

LORENZO BRESCHI

Prof. Lorenzo Breschi ir restauraciju un zobarstniecibas materialu profesors Bolonas Universitate. Vinš aktivi iesaistas emaljas un dentina ultrastrukturalo
aspektu petijumos. Vinš ir bijušais Zobarstniecibas materialu akademijas (ADM) prezidents, Eiropas Konservativas zobarstniecibas federacijas (EFCD) ieveletais prezidents, Zobarstniecibas materialu grupas IADR ieveletais prezidents, Italijas Konservativas zobarstniecibas akademijas (AIC) ieveletais prezidents, Starptautiskas adhezivas zobarstniecibas akademijas (IAAD) ieveletais prezidents.

Atsauces

1. Cowen M, Cunha S, Powers JM. Novel Cement Bond Strength to Multiple Substrates.
DENTAL ADVISOR Biomaterials Research Center, Biomaterials Research Report, Number
132 - June 16, 2020. 2. Patel N, Anadioti E, Conejo J, Ozer F, Mante F, Blatz M. Bond
Strength of Different Self-Adhesive Resin Cements to Zirconia” (2021). Dental Theses.
62. https://repository.upenn.edu/dental_theses/62 3. Yoshihara K, Nagaoka N, Maruo Y,
Nishigawa G, Yoshida Y, Van Meerbeek B. Silane-coupling effect of a silane-containing
self-adhesive composite cement. Dent Mater. 2020 Jul;36(7):914-926. 4. Irie M, Tokunaga
E, Maruo Y, Nishigawa G, Yoshihara K, Nagaoka N, Minagi S, Matsumoto T. Shear bond
strength of a resin cement to CAD/CAM Blocks for molars. P-2, 37th Annual Meeting of the
Japanese Society of Adhesive Dentistry 2018. 5. Ohara N. Bonding strength of resin cement
containing silane coupling agent to dentin or core resin. Results presented at the 150th
meeting of the Japanese Society of Conservative Dentistry. 6. Breschi L, Josic U, Maravic
T, et al. Selective adhesive luting: A novel technique for improving adhesion achieved by
universal resin cements. J Esthet Restor Dent. 2023;1-9. doi:10.1111/jerd.13037

Presented by Kuraray Noritake Dental Inc.

Highly translucent multi-layered zirconia developed by a proprietary material and manufacturing method from Japan

CURRENT STATUS AND FUTURE PROSPECTS OF ZIRCONIA RESTORATIONS

In this issue, we asked Markus B. Blatz, Professor at the University of Pennsylvania, USA, Aki Yoshida (Gnathos Dental Studio) and Naoki Hayashi (Ultimate Styles Dental Laboratory), both dental technicians active in the USA and international instructors for Kuraray Noritake Dental Inc., to give their views on zirconia restorations and their outlook for the future.

WITH THE INTRODUCTION OF ZIRCONIA, THE MAINSTREAM OF PROSTHETIC TREATMENT HAS SHIFTED FROM METAL CERAMICS¹ TO ZIRCONIA CERAMICS². WHAT CHANGES HAVE OCCURRED WITH THE INTRODUCTION OF ZIRCONIA?

Blatz: My mentor for my first Ph.D. in dental materials was in the group that developed lithium disilicate and glass-infiltrated alumina. Therefore, I have seen the evolution of dental ceramic materials, including zirconia, which is the subject of this presentation, up close and personal.

Early zirconia was white, opaque, and not as esthetic as today. However, there is no doubt that zirconia ceramics were much more esthetic than metal ceramics. At the same time, however, we often heard the opinion that bilayer zirconia ceramic restorations were problematic, and this provoked much discussion. We conducted a large study in collaboration with a Boston laboratory to compare more than 1,000 posterior porcelain-fused-to-metal crowns and 1,100 posterior porcelain-fused-to-zirconia crowns and found no difference in chipping or fracture rates after about seven years. This proves that bilayer zirconia ceramics are safe when used with the proper veneering materials and the proper sintering and cooling protocols. The fact that zirconia became established as it is today is a major change for dentistry in general.

Yoshida: I also switched from metal ceramics to zirconia ceramics, and now I don't use metal anymore. It used to take a lot of time and effort to invest and cast metal, observe it with a microscope, and fit it. Considering the recent rise in metal prices, it has also become more cost-effective. In addition, I am allergic to metal and have a skin rash every time I have a prosthetic processed, so the shift to zirconia ceramics as the mainstream prosthetic is a welcome change. Of course, the use of zirconia has also improved esthetics. The translucency of zirconia is the greatest advantage that metal does not have.

Hayashi: Yes, that's right. The big advantage of zirconia is that if the abutment is not strongly discolored, it no longer needs to be treated with an opaquer. It was not easy to control the reflection of light from the operative tooth when fabricating metal ceramics. In addition to the esthetic advantage, the prosthetic space can be thinner than that of metal ceramics.

1. Metal ceramics: Prosthetic made of metal frame with porcelain.
2. Zirconia ceramics: Prosthetic made of zirconia frame with porcelain.

THE YEAR 2023 MARKED THE 10^TH ANNIVERSARY OF THE FIRST MULTI-LAYERED ZIRCONIA – KATANA™ ZIRCONIA ML. SINCE THEN, HOW DO YOU THINK HIGHLY TRANSLUCENT MULTI-LAYERED ZIRCONIA HAS REVOLUTIONIZED PROSTHETIC DEVICE MANUFACTURING?

Yoshida: I feel the ability to extend the zirconia frame to the occlusal surface and the incisal edge is the greatest advantage of using highly translucent multilayered zirconia. This allows us to provide crowns of both esthetics and strength, even for patients with para function. I have also made a zirconia Maryland bridge using highly translucent multi-layered zirconia, and it is doing very well. There are some cases where it is not possible to use zirconia, but still, it is wonderful to have a wider range of options.

Blatz: Many people still have the impression that zirconia cannot be bonded to tooth structure, but resin cement can be used to bond zirconia to tooth structure after proper pretreatment. Clinical studies of resin-bonded zirconia bridges have shown very high success after 10 or 15 years. Currently, resin bonding is recommended for very thin, highly translucent zirconia, rather than cementation. However, it should be added that this requires the dentist and technician to understand the proper bonding technique for zirconia.

In addition, Kuraray Noritake Dental's multi-layered zirconia has revolutionized monolithic zirconia without the need for veneering porcelain. However, this has also resulted in the need for dental technicians to shift to a different approach: instead of building up the restoration as with veneering ceramics, esthetic features are created on the outer surface in each case.

Maxillary 6 anterior monolithic crowns (Markus B. Blatz)

Fig. 1a and b: Initial examination.

Fig. 1c: Simulation of final prosthetic restoration.

Fig. 1d: Completed prosthetic on model (monolithic crown using KATANA™ Zirconia STML).

Fig. 1e and f: Final restoration (Dr. Julian Conejo and Sean Han, CDT).

Two cases of Maryland bridge and laminate veneers and a mandibular canine single crown implant superstructure (Aki Yoshida)

Fig. 2a and b: Case 1: A case of a congenital defect of a lateral incisor was restored with a Maryland bridge. Since the proximal and distal width of the defect was greater than the central incisor, a non-prep veneer was fabricated on the central incisor to balance the proportions. KATANA™ Zirconia STML was used for the Maryland bridge. Note the harmony between the zirconia frame extended to the incisal edge and the transparency of the laminate veneers made of Super Porcelain EX-3™ on the central incisors. This case demonstrates the characteristics of zirconia, which combines strength and esthetics.

Fig. 3a to c: Case 2: A case of a screw-retained crown restoration of an implant placed in a mandibular canine tooth. Extension of the zirconia frame from the entire lingual side to the incisal margin prevents fracture of the porcelain by the screw access hole edges and canine guides. KATANA™ Zirconia STML provides natural transparency even when zirconia is exposed at the incisal edge.

Maxillary 4 Anterior teeth implant bridge (Naoki Hayashi)

Fig. 4a to f: Implant bridge of maxillary four anterior teeth using implants placed in the maxillary bilaterallateral incisors as abutments and maxillary bilateral central incisorsaspontics. The lingual side is fully backed with zirconia and the labial side is minimally layered with CERABIEN™ ZR.

Hayashi: Indeed, the highly translucent multilayered zirconia has expanded the possibilities of monolithic crowns. For patients with high occlusal forces, monolithic crowns are suitable in terms of strength, and with the use of highly translucent multilayered zirconia, it is possible to achieve a certain level of esthetics with monolithic crowns. In fact, some patients are happy with it. However, at least in the current situation, we believe that if patients and dentists want high-end esthetics, then porcelain buildup is necessary, and monolithic crowns are only an option.

Blatz: The variety of options available is the advantage of zirconia. The dentist and the technician can work together to provide the best possible outcome for the patient.

Yoshida: In terms of options, Kuraray Noritake Dental's zirconia can be sintered in a short time (approximately 90 minutes) in addition to the normal sintering time (7 hours) using a zirconia raw material and manufacturing method developed by Kuraray Noritake Dental, which is an advantage in that it can be used for immediate restorations, remanufacturing and other unexpected situations.

FINALLY, DO YOU HAVE A MESSAGE FOR THE NEW GENERATION OF DENTISTS AND DENTAL TECHNICIANS?

Blatz: I encourage my students and colleagues to always do their best. This leads to good results, makes you happy, and makes you feel satisfied with your life. Some people only try to get rich, but just accumulating wealth is never happiness. The second is to keep an open mind. Nowadays, we are inundated with information through social media.

Some of it is very stimulating and wonderful, but there is also a lot of it that is wrong. On the other hand, there are those who believe that everything one leader says must be done. I would like to tell them, "Make sure you get your information from reliable sources, and then choose reliable information for yourself. Dentistry is changing, so let's keep an open mind. The most important thing is that the patient is ultimately satisfied with the results.

Hayashi: I would like the future generation to learn more about tooth morphology, occlusion, and fit. Color is the essence of the quality of the final prosthetic device, but we need to learn tooth morphology, occlusion, and fit before we learn color. We are all about creating a prosthetic device that will function in the patient's mouth for the long term, and that is our goal. There will be new technologies and materials in the future, but their essence will never change. I hope that you will always remember what is important in your clinical practice. This is why basic knowledge of anatomy and function is necessary.

Yoshida: New technologies and materials will continue to emerge. But human teeth will not change. The most important thing is to provide the best possible care to the patient. I hope that you will accumulate such experiences, and that when you reach the end of your life, you will be able to say that you are glad you chose this profession.

Thank you very much for the meaningful discussion today.

Source: QDT Vol.49/2024 April
The magazine may not be printed from the web and may not be forwarded
No reproduction or reprinting allowed

Dentists:

KATANA™ Zirconia YML offers an unmatched blend of aesthetics and mechanical properties, but also provides for cost and time efficiencies.

Recognised for its strength and density at point of manufacture, the material delivers incredible hardness in its green state. This offers the fully validated opportunity to make adjustments in morphology directly after milling.

These qualities, along with its strength and translucency once sintered, deliver the possibility to produce a wide range of high aesthetic indications. KATANA™ Zirconia YML has set a new benchmark in prosthetic dentistry.

It provides dental technicians with a material that is truly universal with no compromises required.

KATANA Zirconia YML in a Nutshell

KATANA Zirconia YML represents a pinnacle of zirconia technology. With its multi-layered structure, it offers a seamless gradation of colour, strength and translucency that mimics natural teeth, making it an ideal choice for the entire indication spectrum.

The material's unique composition allows for high-speed sintering (up to 3-unit bridges), which significantly reduces production time without sacrificing optical or mechanical properties.

Colour Gradation and Physical Properties

The colour gradation of KATANA Zirconia YML is designed to replicate the natural colour transition of human teeth, from the dentin core to the translucent enamel surface.

This combined with the material's impressive flexural strength of up to 1,100 MPa and translucency of up to 49%, enables the production of restorations that are virtually indistinguishable from natural dentition.

Applications and Advantages of KATANA Zirconia YML

KATANA™ Zirconia YML's versatility extends to a wide range of indications, including crowns, veneers, inlays, onlays, and bridges of all sizes. With its strong body and highly translucent enamel layer, it offers exactly the properties required for an unlimited indication range.

Positioning of restorations in KATANA™ Zirconia YML discs is extraordinarily easy. The reason is that the gap between the lowest flexural strength found in the enamel area and the highest flexural strength found in the lowest body layer is comparatively small. Moreover, the Body Layer 1 that is found adjacent to the enamel layer already offers a flexural strength that is higher than the 800 MPa requested for bridges with four or more units. Consequently, the material is classified as a Class 5 zirconia and users are on the safe side whenever they place their long-span restorations in the middle of the blank.

Positioning of long-span restorations in the middle of the disc.

Revolutionizing Sintering with High-Speed Capabilities

One of the groundbreaking aspects of KATANA Zirconia YML is its compatibility with high-speed sintering protocols. This capability allows dental laboratories to expedite the production process, delivering high-quality restorations in a fraction of the time traditionally required. Sintered during normal working hours at daytime, small restorations can be finished within hours, while the sintering load at night is reduced automatically. Great option not only for rush cases!

The high-speed sintering process does not compromise the material's optical or mechanical properties, maintaining its aesthetics and strength.

Recommended Finishing Techniques for Optimal Results

KATANA Zirconia YML is a beautiful and aesthetic material in its own. Therefore, when it comes to finishing, CERABIEN™ ZR FC Paste Stain is a great option.

KATANA Zirconia YML: A Testament to Innovation in Dental Materials

KATANA Zirconia YML stands at the forefront of dental material technology, offering outstanding aesthetics, strength, and efficiency. Its introduction has marked a significant advancement in the capabilities of dental technicians, allowing for the creation of restorations that truly mimic the beauty of natural teeth in a fraction of time.

As the dental industry continues to evolve, KATANA Zirconia YML remains a testament to the relentless pursuit of excellence in restorative dentistry.

For more detailed information on KATANA Zirconia YML, including technical guide, FAQs and Clinical cases, visit Kuraray Noritake Dental's YML dedicated page.

Interested in articles, user experience or clinical cases using KATANA Zirconia YML? Check the blog section of our website! 

Mathias Fernandez Y Lombardi

EU Scientific Manager
Dental Ceramics & CAD/CAM Materials
Kuraray Europe GmbH

Welcome to the latest edition of BOND Magazine, your essential guide to cutting-edge advancements and techniques in the world of dentistry. Volume 11 is packed with insightful articles, expert interviews, and practical advice designed to enhance your dental practice or laboratory and keep you at the forefront of the profession.

In this issue, we dive into the simplicity and predictability of the flowable injection technique with Michał Jaczewski. Learn how this minimally invasive method can transform patient outcomes with minimal preparation, making it accessible for both beginners and experienced practitioners alike.

We also explore the transformative potential of universal resin cement in Prof. Lorenzo Breschi's article, which introduces a third application mode that could revolutionize how you approach luting for challenging restorations.

Meanwhile, Dr. Michael Braian shares his comprehensive guide to dental rehabilitation using digital workflows, ensuring you can leverage the latest technology for superior patient care.

This volume also includes a case reports by Dr. Jose Ignacio Zorzin - discussion on rationalizing clinical procedures with universal adhesives. These insights will help streamline your workflows, reduce chair time, and enhance patient satisfaction.

From detailed explorations of high-performance materials to interviews with leading dental laboratory professionals like Alexander Aronin and Andreas Chatzimpatzakis, BOND Magazine offers a wealth of knowledge for all dental professionals.

Click here to read. Enjoy reading, and let us inspire your journey towards excellence in dentistry.

Start Reading: BOND | VOLUME 11 | 07/2024

Previous versions:

BOND | VOLUME 10 | 10/2023

BOND | VOLUME 9 | 08/2022

BOND | VOLUME 8 | 12/2021

BOND | VOLUME 7 | 10/2020

By Dr. Adrien Lavenant

In many clinical situations, composite restorations offer advantages over all-ceramic restorations. The treatment is less costly, usually less invasive, and the restorations can be modified and repaired at any time. When it comes to restoring multiple teeth, however, a free-hand layering approach used to build up every tooth separately can be very time-consuming and labour-intensive. In these situations, the flowable injection technique –also referred as injection moulding – is a great alternative. It is minimally invasive, suitable as a temporary or permanent solution to issues around tooth wear and irregular shape, and time-efficient in the clinical setting.

Essential materials

While the planning phase including the creation of the wax-up can be accomplished in the traditional way or in the digital workflow and components may differ depending on the preferred way of working, two materials are essential for the implementation of the flowable injection technique: A transparent silicone and a flowable composite. The silicone is used to produce an index and transfer the planned shape of the restorations from the wax-up into the patient’s mouth. Transparency is needed to make sure that the flowable composite will be cured properly through it – an important precondition for high-quality results. The flowable composite is injected into the silicone index. While offering a great flow behaviour during injection, the selected material should also exhibit a high mechanical stability for durability. CLEARFIL MAJESTY™ ES Flow Low (Kuraray Noritake Dental Inc.) offers the desired properties. One possible way to combine the materials and implement the technique is illustrated using the following patient case.

Important step in a complex treatment

This patient came to the dental office after orthodontic treatment with a request to improve the aesthetics of her smile. In the maxillary and mandibular anterior region (incisors and canines), severe tooth wear was diagnosed, with the maxillary central incisors most severely affected (figs. 1 to 4). To restore her maxillary teeth as quickly as possible, the least invasive immediate treatment option was selected: A smile makeover with composite using the flowable injection technique. In the long term, it is planned to perform a full-mouth rehabilitation with all-ceramic restorations.

Fig. 1. Initial situation: Lateral view from the right.

Fig. 2. Initial situation: Lateral view from the left.

Fig. 3. Initial situation: Frontal view.

Fig. 4. Close-up of the severely worn central incisors.

Shade determination and index production

After an analysis of the tooth colour using two different methods (figs. 5 and 6), a digital impression was taken and a wax-up designed with dedicated CAD software. The wax-up model was then printed (fig. 7); it served as the basis for the production of the transparent silicone index (figs. 8 and 9). After complete curing of the material, injection channels were integrated at the incisal edges of each tooth to be restored.

Fig. 5. Determination of the tooth colour using a shade guide.

Fig. 6. Picture taken with a white_balance grey reference card for objective shade quantification.

Fig. 7. 3D-printed model of the upper jaw with the virtually designed wax-up.

Fig. 8. Silicone index produced over the wax-up model with injection channels at the incisal edges of each tooth.

Fig. 9. Close-up view of the index with injection channels.

Shade validation and preparations for injection

To validate the selected shade, small amounts of composite (buttons) in three different shades were applied to the untreated surface of the left central incisor and cured (fig. 10). In this way, it is possible to visualize the colour of the composites in the mouth. The selected shade was A1. The aprismatic enamel layer on the surfaces of the six maxillary anterior teeth was carefully removed with burs to create ideal bonding conditions (fig. 11). The teeth were then isolated with clear matrix strips for the implementation of the bonding protocol on the right canine and central incisor and left lateral incisor: To provide for proper interproximal separation and contacts, it is advisable to treat every other tooth and then repeat the procedure for the rest. The teeth were etched with phosphoric acid, rinsed and carefully dried before applying the selected adhesive (CLEARFIL™ SE PROTECT, Kuraray Noritake Dental Inc.) (fig. 12). For separation and protection of the adjacent teeth during composite injection, PTFE tape is a great choice (fig. 13).

Fig. 10. Composite buttons applied to the left central incisor for shade validation.

Fig. 11. Roughened tooth surfaces.

Fig. 12. Etched and bonded surfaces of the right canine, right central incisor and left lateral incisor after isolation with clear matrix strips.

Fig. 13. Protection of the adjacent teeth with PTFE tape.

Composite injection and treatment of the other teeth

After its application, the silicone index was placed in the mouth and CLEARFIL MAJESTY™ ES Flow Low in the shade A1 injected tooth by tooth through the injection channels (fig. 14). What followed was proper light curing of the composite through the index. The situation after index removal is shown in figure 15. At this stage, the excess still needed to be removed, before protecting and separating the already restored teeth with PTFE tape and repeating the procedure for the other lateral incisor, central incisor and canine.

Fig. 14. Index with injected composite.

Fig. 15. Result after index removal.

Treatment outcome

Once all the excess material was completely removed, the occlusion was checked and adjusted. Finishing and polishing was accomplished with TWIST™ DIA for Composite (Kuraray Noritake Dental Inc.). The immediate treatment outcome is shown in figures 16 to 18, while figures 19 and 20 were taken at a recall after six months.

Fig. 16. Treatment outcome: Frontal view.

Fig. 17. The new smile.

Fig. 18. Treatment outcome: Occlusal view.

Fig. 19. Appearance of the teeth…

Fig. 20. … at the six-month recall.

Conclusion

Thanks to advances in restorative materials and technological tools, it is nowadays possible to restore our patients' smiles quickly and reproducibly. The flowable injection technique is one of the most successful examples of modern aesthetic treatments using composite resin. CLEARFIL MAJESTY™ ES Flow has all the qualities needed to carry out these treatments under the right conditions.

About the Author

Dr. Adrien Lavenant obtained his degree in Dentistry from Aix-Marseille University in 2010. He pursued post-university training in periodontology, implantology, and restorative and aesthetic dentistry (Aix-Marseille University and Paris). Dr. Lavenant has been a former teaching staff member at Aix-Marseille University since 2011 and continues to teach in the postgraduate programme in restorative and aesthetic dentistry. He practices in his private clinic in Aix-en-Provence, specializing in restorative, prosthetic, and aesthetic implant dentistry. He has been a member of the international Bio-Emulation group since 2019 and shares his patient care philosophy in accordance with the principles of biomimetic dentistry.

By Manabu Suzuki, Director of Dental Division, Kuraray America, Inc.

Kiyoko Ban, a prominent figure in the dental technology field, has made a lasting impact as a researcher, developer, and founder of Noritake Dental business (Fig. 1). Renowned for her contributions to dental porcelains like Noritake's CZR and EX-3, and KATANA™ Zirconia, Ms. Ban stands as a pivotal force in the global advancement of dental technology, earning her the esteemed reputation of developer and marketer within the dental technology community.

After completing her university education in Nagoya, Ms. Ban initially assisted in her family's gas station business. However, driven by a desire for a career change, she enrolled in a newly established dental technician college in Nagoya at the age of 30. Her aspiration was to enter a field where gender distinctions held no sway, offering the potential for worldwide recognition based on technical mastery.

In 1977, a college-sponsored tour to American dental laboratories ignited Ms. Ban's dream to work in the United States. However, she delved into research across various fields such as chromatology (the science of color), ceramics and metals, finding a newfound passion for research over clinical work after graduation because she was offered a "Curriculum Chief" position from the college when she graduated (Fig. 2).

Fig. 2. Ms. Ban, a curriculum chief at the Dental Technicians College, devoted her evenings to material research.

Fig. 3. In the 1990s, Ms. Ban actively engaged in promoting EX-3 through sales efforts in Italy.

Her teaching career spanned from the age of 34 to around 40, during which she pioneered porcelain training sessions for technical improvement and arranged lectures over weekends by famous speakers such as Masahiro Kuwata.

At the age of 40, she resigned teaching career and pursued her research career. The opportunity to conduct full-scale experiments led her to the discovery of a company with advanced ceramic technology "Noritake Co., Limited", renowned for its tableware. In 1986, Cusp Dental Supply, a research institute, was established by Ms. Ban in Nagoya, focusing on the development of materials for PFM crowns. The commercialization of Super Porcelain AAA (EX-3) in 1987 marked a significant milestone, addressing issues prevalent in porcelain materials of that time, such as cracks, greening, and fluorescence.

She began traveling all over Japan and around the world to sell the products she had developed and went on to develop new products that were needed by dental technicians worldwide (Fig. 3). She continued to develop new products such as CZR, CZR Press, and KATANA™, the world's first multilayer zirconia.

Ms. Ban has been actively involved in mentoring students and graduates seeking opportunities to work overseas. During summer vacations, she took students and professionals interested in working abroad to countries like Australia, Germany, and the United States. The aim was to visit dental clinics, dental technician schools, and laboratories, fostering exposure and learning in an international context.

Simultaneously, Ms. Ban delved into researching non-precious dental technology. Inspired by her exposure to the term "non-precious" during her time in the United States, she anticipated its potential in Japan. Her research presented at lectures and events highlighted the shift in the landscape as the price of gold surged, rendering precious alloys containing significant amounts of gold impractical for PFM crowns.

As the demand for their developed products grew, the need for global acceptance became apparent. In 1990, Cusp Dental Research was established in Manhattan, New York, marking Ms. Ban's foray into establishing a company overseas. Despite the unfamiliarity with legal procedures and the challenges of setting up a foreign company, Ms. Ban, driven by determination, overcame these hurdles. The establishment of the company in the United States expanded their presence internationally Fig. 4).

Fig. 4. Capturing the essence of ISC 1996 - the International Symposium on Ceramics in Orlando, FL..

Noritake Dental Supply Co., Limited was established in 1998 by the Noritake Co., Limited, which aimed to further expand its dental business. Despite the absence of a capital relationship with Noritake at the time of establishing the research laboratory, Ms. Ban played a key role in joint research efforts with Noritake. Then she was invited to this company as the position of president, owning 60% of the stock, while Noritake held 40% (Fig. 5).

Besides Noritake Dental business, she continued expansion with the establishment of a dental laboratory in Boston in 1995. Despite the challenges posed by the September 11, 2001 World Trade Center incident, they acquired their building in Boston, integrating their New York laboratory into the Boston operations.

Ms. Ban's tenure as president of Noritake Dental Supply persisted until 2009, but organizational changes following the merger with Kuraray in 2011 led to her transition into an advisory role (Fig. 6). Despite the shift in responsibilities, her commitment to the dental technician profession remained steadfast.

Fig. 5. Noritake Dental Supply Inc Inauguration Party, 1998.

Kiyoko Ban's path encapsulates not just a career but a legacy in the field of dental technology. From her early struggles in a tooth carving class to establishing and expanding international laboratories, Ms. Ban's story is one of determination, innovation, and a deep-rooted commitment to advancing the dental technician profession.

Fig. 6. A scene from Ms. Ban’s retirement celebration as Noritake Dental Supply president, surrounded by esteemed dental technicians from around the world.

UNFORGETTABLE WEEK

In April, a team from Kuraray Noritake Dental’s European arm accompanied 18 Key Opinion Leaders (KOLs) from Germany, Italy, Spain, France, Turkey, Poland, England, Romania, Switzerland, the Czech Republic, and Denmark to Kuraray Noritake Dental’s roots in Japan. The week was an incredible blend of professional exchange, cultural immersion, and shared experiences.

The European group included an interdisciplinary team of dentists, dental technicians, professors, and researchers. They toured Kuraray Noritake Dental’s two production sites in Niigata (chair-side manufacturing) and Nagoya (lab-side products) and visited the Head Office in Tokyo.

Visit to the production facility for chair-side products in Niigata.

INTERDISCIPLINARY AND INTERNATIONAL EXCHANGE

As you can imagine, this was a fantastic opportunity for both Kuraray Noritake Dental’s European employees and KOLs to have lively exchanges with Japanese developers and production personnel. Our KOLs highly appreciated the opportunity to present their own work and ongoing results while sharing tips and techniques with the Japanese members.

The importance of this trip for both the KND employees and the European travel group was underlined by the participation of the Head of Kuraray Noritake Dental (Yamaguchi-san) and the inventor of Noritake dental porcelain (Kiyoko Ban). In her welcome speech, she emphasized what an extraordinary opportunity this interdisciplinary and international exchange represents and how pleased she was about the numerous visitors.

Kiyoko Ban during her welcome speech for the delegation from Europe.

Head of Kuraray Noritake Dental (Yamaguchi-san) together with Dr. David Gerdolle, Jakab Daniel, and Honoré Morel during lunch in the Tokyo office.

The tour proved that there really is no substitute for face-to-face, hands-on interaction when it comes to discussions between product developers and specialists as well as seeing behind the scenes for a direct insight into production and quality assurance.

As Dr David Gerdolle said: “Kindness, perfect organization, dedication to precision and professionalism are a rare and precious combination in the actual world. My deepest gratitude to the Kuraray Noritake company for this unforgettable week in Japan.”

EXPLORING JAPAN

However, the visit wasn’t all about work. There was a fabulous opportunity to see Mount Fuji in all its glory on the train ride from Nagoya to Tokyo and as well as a unique chance to explore Japanese culture. Not to forget the visit to Noritake Garden in Nagoya, where the history and traditional art of fine tableware through to modern high-tech materials are on display.

Exhibitions at the Noritake Museum in Nagoya.

As Daniel Dunka (MDT) said: “The whole trip was absolutely wonderful, and I’m grateful to Noritake for the invitation. It has been a wonderful experience mingling with colleagues from all over the world in such a beautiful environment. It has been an inspiration for me and I look forward to continuing to work with your wonderful materials and of course your amazing team.

Jakab Daniel (MDT) added: “The organizational culture [in Japan] is fascinating, it is amazing to be a part of the whole manufacturing process of Noritake ceramics, Zirconium KATANA and all Kuraray products. Very good discussions, opinions, suggestions” while MDT Mathias Berger from France summed up the whole visit with: “Thank you so much for your invitation, I realized a dream.” 

Available Now!

Have you ever produced a zirconia restoration without obtaining the outcome you expected? Most dental technicians probably have. The bad thing is that aesthetic flaws such as colour deviations or white spots and technical issues like cracks can occur and require remakes. The good thing is, however, that those problems are usually avoidable. Do you know how?

We would like to show you – in the new KATANA™ Zirconia Troubleshooting Handbook we just completed. On 30 pages, this handbook summarized the most important facts about modern zirconia-based restorative materials, their selection, the KATANA™ Zirconia line-up and, finally, possible aesthetic or technical problems, their origin and solutions to overcome them.

Let us assume that the beauty of your restorations is limited due to a lack of translucency. By looking up the problem “lack of translucency”, you will find a compact, well-structured overview of possible causes and adequate solutions. The recommendations include selecting dry instead of wet milling, abstaining from sandblasting the restoration surface and checking of the sintering parameters, quality of the sintering beads and position of the restoration in the furnace. For more details, problems and solutions, download the handbook!

DOWNLOAD NOW

Article by Prof. Lorenzo Breschi

Fewer bottles, more choices – this is possibly the shortest way to describe the category of universal resin cements. Being self-adhesive, these dual-cure resin-based cements allow for a single-component workflow without the need for separate tooth or restoration primers in many clinical situations. The bond strength obtained in this way is usually high enough to provide for a stable bond between the tooth and the restoration in a wide range of indications. However, it is slightly lower than that achieved with conventional resin cement systems consisting of several components (typically tooth primer, resin cement and restoration primer).

Apart from the self-adhesive application mode, universal resin cements may be combined with additional system components to increase the bond strength to tooth structure or the restorative material, respectively. This opens up new possibilities with regard to the product’s use: depending on the required or desired bonding performance, the universal resin cement may be applied alone or in combination with a tooth primer, a restoration primer or both components. In addition, hybrid concepts become feasible, as explained in this article that focuses on PANAVIA™ SA Cement Universal (Kuraray Noritake Dental Inc.) as an example.

Self-adhesive luting: for many indications

PANAVIA™ SA Cement Universal is a dual-cure universal resin cement that is indicated for a wide range of applications when used in the self-adhesive mode. The bond established to restorative substrates (including silicate ceramics) is high without the use of a separate primer or silane^1-4. This is due to two different adhesive monomers contained in the formulation – the Original MDP Monomer and the LCSi Monomer (a long carbon-chain silane coupling agent responsible for a strong chemical bond to silicate ceramics). Hence, it is possible to use the resin cement without any additional component applied on the side of the restoration – even in cases with a lack of retention and consequently high bond-strength requirements.

A strong bond to enamel and dentin is also obtained in the self-adhesive mode. In certain situations, however, it may be useful to further increase the bond strength to tooth structure with the aid of a tooth primer.

Adhesive luting: for challenging situations

The tooth primer recommended for PANAVIA™ SA Cement Universal is CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.). Its application is recommended whenever a user feels that the treatment would benefit from an extraordinarily strong and durable chemical bond, i.e. in particularly challenging situations with insufficient mechanical retention. The effectiveness of this measure has been confirmed in an in-vitro study conducted in Japan, in which the 24-hour micro-tensile bond strength to dentin was increased significantly by the application of the universal adhesive⁵. When a separate adhesive is used, however, the importance of a completely dry working field increases. The reason is that the moisture tolerance of resin cements is usually higher than that of adhesives. Consequently, the application of a rubber dam is highly recommended.

Selective adhesive luting: for short abutments and subgingival margins

For situations in which proper isolation of the working field with a rubber dam is difficult, a third application option is available and proposed by a group of Italian researchers: Selective Adhesive Luting. In this case, CLEARFIL™ Universal Bond Quick is applied solely to those parts of the prepared tooth that allow for proper moisture control, while relying on the self-adhesive functionality of PANAVIA™ SA Cement Universal in areas where it is challenging to obtain the desired dry working field. Situations which are predestined for this technique are abutment teeth with a subgingival preparation margin and particularly short abutment teeth (that hinder the placement of a rubber dam).

The effectiveness of the selective adhesive luting technique has been verified in an in-vitro study that compared the three adhesive strategies – self-adhesive luting, full adhesive luting and selective adhesive luting – with the aid of shear bond strength testing⁶. The results of the tests show that users are able to enhance the bond strength of PANAVIA™ SA Cement Universal to dentin and enamel by applying the adhesive to a part of the tooth surface only. For the cementation system consisting of PANAVIA™ SA Cement Universal and CLEARFIL™ Universal Bond Quick, the full adhesive and the selective adhesive approach led to similar outcomes.

For situations in which proper isolation of the working field with a rubber dam is difficult, a third application option is available and proposed by a group of Italian researchers: Selective Adhesive Luting.

RECOMMENDED STEPS FOR SELECTIVE ADHESIVE LUTING

Fig. 1. Tooth preparation.

Fig. 2. Selective etching of the enamel with phosphoric acid etchant.

Fig. 3. Application of the universal adhesive + air-drying.

Fig. 4. Crown placement after application of the resin cement into the crown.

Fig. 5. Tack-curing.

Fig. 6. Excess removal and final light curing.

Fig. 7. Treatment outcome at a recall after one year.

Benefits of selective adhesive luting

Apart from the desired (long-term) increase in bond strength achieved by applying a separate adhesive to a part of the or the whole prepared tooth surface, the technique offers additional benefits. Compared to multi-step cementation systems, the protocol is simplified as no separate restoration primer is needed. Light-curing of the adhesive is not required as long as the user stays within the recommended system. And in contrast to the full adhesive approach requiring rubber dam placement, the need for this step is eliminated in the selective adhesive approach. In this way, the chair-time is reduced and patient comfort increased.

Conclusion

Depending on the indication, clinical variables and individual preferences, users of universal resin cements like PANAVIA™ SA Cement Universal may select the technique that is likely to deliver the best clinical outcomes. It is this flexibility and the generally wide range of applications that makes the innovative product category truly universal. With fewer components to be used, universal materials facilitate the streamlining and standardization of clinical procedures, while with fewer bottles to be stored, they help staff gain control over order and storage management as well.

Dentist:

LORENZO BRESCHI

Prof. Lorenzo Breschi is Professor of Restorative Dentistry and Dental Materials at the University of Bologna. He is actively involved in research on the ultrastructural aspects of enamel and dentin. He is Past-President of the Academy of Dental Materials (ADM), President-Elect of the European Federation of Conservative Dentistry (EFCD), President-Elect of the Dental Materials Group IADR, President-Elect of the Italian Academy of Conservative Dentistry (AIC), President-Elect of the International Academy of Adhesive Dentistry (IAAD).

References

1. Cowen M, Cunha S, Powers JM. Novel Cement Bond Strength to Multiple Substrates. DENTAL ADVISOR Biomaterials Research Center, Biomaterials Research Report, Number 132 – June 16, 2020.
2. Patel N, Anadioti E, Conejo J, Ozer F, Mante F, Blatz M. Bond Strength of Different Self-Adhesive Resin Cements to Zirconia” (2021). Dental Theses. 62. https://repository.upenn.edu/dental_theses/62.
3. Yoshihara K, Nagaoka N, Maruo Y, Nishigawa G, Yoshida Y, Van Meerbeek B. Silane-coupling effect of a silane-containing self-adhesive composite cement. Dent Mater. 2020 Jul;36(7):914-926.
4. Irie M, Tokunaga E, Maruo Y, Nishigawa G, Yoshihara K, Nagaoka N, Minagi S, Matsumoto T. Shear bond strength of a resin cement to CAD/CAM Blocks for molars. P-2, 37th Annual Meeting of the Japanese Society of Adhesive Dentistry 2018.
5. Ohara N. Bonding strength of resin cement containing silane coupling agent to dentin or core resin. Results presented at the 150th meeting of the Japanese Society of Conservative Dentistry.
6. Breschi L, Josic U, Maravic T, et al. Selective adhesive luting: A novel technique for improving adhesion achieved by universal resin cements. J Esthet Restor Dent. 2023;1-9. doi:10.1111/jerd.13037.

May 15th, 2024 at 21:00 CET

From margin elevation to restoration

Did you ever wonder how to optimize teamwork, efficiency, and patient satisfaction in the context of a combined endodontic and restorative treatment? As a general or restorative dentist, you can easily contribute to streamlined procedures and better outcomes for your patients. The measures to be taken are in the center of this webinar by experienced and knowledgeable Dr. Wiktor Pietraszewski.

Endodontic treamtment and pre-refferal strategies

In the first part of his lecture, Dr. Pietraszewski reveals how to proceed before referring the patient to the endodontic specialist to improve the overall prognosis of the treatment on the one hand, and the patient experience on the other. Materials and techniques, such as deep margin elevation, caries removal, and tooth build-up, will be described and examined. But most importantly, many practical tips will be shared with the audience.

Post-endodontic restoration options for long term success

In the second part, the speaker will focus on post-endodontic treatment. He will describe the available materials and types of post-endodontic restorations. Dr. Pietraszewski will shed light on the most important factors guiding the most crucial treatment decisions and will elaborate on the factors influencing long-term success.

Go to the Facebook Event of the webinar and click „Livevideo”!

We look forward to seeing you!

About the speaker

Dr. Pietraszewski is a general and restorative dentist working in private practice in London. He utilizes biomimetic adhesive protocols in his restorative cases and uses gold standard materials to emulate the natural appearance, bio-mechanical function, and internal structure of teeth when restoring them.

He has a special interest in direct and indirect restorations in the posterior dentition, and his dentistry is fueled by his passion for dental photography.

From The Medical University in Lodz (Poland) to private clinics in Malta and London, his dental journey reflects dedication to excellence.