Tehnia aspets f mpete dente nsttin
This atie deas with tehnia aspets f mpete dentes as we as the imptane f gd mmniatin between the iniian and the tehniian. The bjetives f tehniians f eah mpnent ae disssed.
In this pat, we wi disss:
* Tehnia bjetives in the pepaatin f a ast f tay nsttin.
* Tehnia bjetives f im pepaatin.
* Aspets f tth paement.
* The imptane f gd dentist-tehniian mmniatin
n sevea asins thght this seies, mentin has been made f the need t estabish, and maintain, a gd wking eatinship between the iniian and the tehniian. In de that this eatinship may be psthdntiay pdtive, espet has t be eaned fm bth these membes f the dente team. This eqies that nsisteny f qaity shd be the aim f a stages f mpete dente nsttin and by iniian and tehniian aike.
With the abve in mind, this setin seeks t highight, n a hngiay seqentia basis, the tehnia invvement with eah inia visit. T avid epetitin f eah stage, it wi be assmed standad patie f a wk t be disinfeted in the sgey and in the abaty befe mmenement f eah stage.
Pimay impessin visit
The pimay aim f this visit is t ed, in stk tays, the dente-beaing aeas f eah ah. Ading t the Gides t Standads in Pstheti Dentisty,1 thee ae basi eqiements eqied f pimay impessins, and these ae isted in Tabe 1. In additin t these, it is emmended that the iniian, if nt asting the impessins, wi indiate the extent f the dente-beaing aea. An indiatin, n the pesiptin fm f the spaing f and design f the speia tay(s) is as eqied, as the tehniian annt te fm a stne ast the eative dispaeabiity f tisses and, in nseqene, whee eief is eqied.
Tehniian's bjetives
Fige 1 istates a gd qaity pimay (paste) ast that has faithfy epded a f the eqiements isted in Tabe 1. The identifiatin f the tine f the peiphea extensin f the speia tay, sibed n the ast by the iniian, enabes the tehniian t nstt a speia tay t the itemised insttins f the iniian. An exampe f a gd qaity ight-ed speia tay is shwn in Fige 6, Pat 4 - this tay had a 2 mm spaing veying the ast.
Definitive impessin visit
The aim f this visit is t ed the dente-beaing tisses, at the apppiate degee f tisse dispaement, in additin t eding the fntina width and depth f the si. In this way, sppt, etentin and sme f the aspets f stabiity ae addessed.
Tehniian's bjetives
The definitive impessins ae ast in stne 75% stne-paste mix (in the inteests f stength) and these fntin as maste asts. As was efeed t in Pat 4, the iniian shd sibe, n the definitive impessin, the psitin f the pst-dam and as the panned pesevatin f the peiphea (see Fig. 9, Pat 4).
By bxing t the and aea eevant t the peseved peiphea , the tehniian shd pesent a qaity ast that ny eqies that the iniian insibe the extent f the pst dam.
Eqay, it may be that sme aeas f the ast may eqie t have tin fi added t pde eief aeas, sme aeas, eg ndets, may be bked t sing paste (Fig. 2).
The espnsibiity f the seetin f the mateia t fm the base f the ppe and we ims ests with the iniian. Tabe 2, Pat 5 ists the mateias whih may be sed as bases and mst tehniians shd have the skis t make we-adapted bases (whih wi impat stabiity at the next inia stage) in a f the abve mateias.
When the maste ast has been mpeted t the needs f the patient, the tehniian has t pde ed ims ppe imaestheti nt base (AB) and enta-beaing appaats t the iniian's insttins.
Anedtay speaking, this aspet f the iniian-tehniian intefae is the weak ink f the pesiptin pess as the tehniian ften has n way f knwing whee t pae the abia fae f the ppe im, n des he she knw the height f the abia fae f the im.
It is entiey pbabe that a mbinatin f divese teahing phisphies nening the paement f maxiay teeth n epaement dentes (and ths the fm f the ppe im) amng bth inia and tehngia teahing instittins has ntibted t nfsin n hw tehniians shd make the ppe imAB. py dente tehniqes, the Ama gage the se f devies sh as the aamete and the papiamete (Pat 5) have assisted in heping the tehniian t stmise an ppe imAB that shd nt eqie t mh additinemva f wax.
Whie the same thghts appy f the we nventina ed im, the simpifiatin f the 'Manheste im' the nsttin f the enta-beaing appaats edes the ptentia f nfsin ve dimensina paametes .
It is the bjetive f the tehniian t fabiate a f the mpnent piees f the thid inia visit and t ense that they ae we-adapted, stabe and finished t a high qaity. Faie t have any piee f appaats fit the ast is the fat f the tehniian; the nvese is as te, namey that if the base fits the ast, bt nt the eevant ah, the fat ften ies with the iniian.
Thid inia visit
The aims f this visit ae theefd:
* T detemine the fm f the ppe dente and t pvide ea gideines f the paement f the teeth. This may may nt invve a faebw tansfe, depending n the pefeene f the iniian.
* T eate the mandiba ah t the maxiay ah in a epdibe thee-dimensina pesiptin.
* T seet teeth f apppiate md and shade.
Tehniian's bjetives
n eeipt f the mpeted pesiptin fm the iniian, the tehniian has t eate the ppe ast t the atiat, the nate f whih shd ideay be seeted by the iniian. F simpiity, a Dena faebw has been sed thght this setin. The tehniian tansfes the ppe imAB t the atiat via a tansfe jig (Fig. 3). In this way, the eatinship f the maxiay pane t the patient's ndya axis is tansfeed t the atiat, fming an eqivaent eatinship t the atiat's ndya axis. Pi t mnting the ppe ast nt the atiat, the tehniian shd ense that index gves ae paed n the base f the ast (Fig. 4). This faiitates the pess temed spit-asting whih enabes asts t be emnted aatey nt the atiat pst-pessing. In this way, any pessing-inded sa es may be eiminated. T eiminate es, the gypsm pdt shd be mixed with wate ntaining a fd ing and an anti-expansin agent. The fme enabes gd ntast between the maste ast and the mnting medim whie the atte sbstantiay edes any sma, ptentia es whih might aise in the mnting f asts.
An atenative ptin t the se f indexing gves is the se f magnets t ate the asts t the atiat.
The send task f the tehniian is t mnt the we ast n the atiat in the efeene estabished by the iniian. Again f easns f estabished tehngia pede, the we base shd have index gving paed.
When the ppe and we asts ae atiated, the tehniian ses the teeth f seeted shade and md and aanges the ppe teeth as fws.
* T the fm f the abia sfae f the ppe imAB.
* The pstei teeth ae psitined sh that thei paata sps veay the we idge (Fig. 5).
* Ante-pstei and paat-ba mpensating ves mmene at the ppe fist ma teeth.
we teeth ae set p with the neks f the antei teeth ve the we idge and the enta fssae f the pstei teeth veying the we idge. Patias f tth psitining and setting p may be fnd in standad textbks f denta tehngy f psthdntis.
In additin t skied paement f the dente teeth in wax, the tehniian has the espnsibiity f mbining fm and fntin, ensing that baaned sin exists in etded ntat psitin (P) in evey ase, and baaned atiatin when s eqested by the iniian.
In additin t embedding teeth in wax t este denta appeaane and fntin, the tehniian shd then md the wax epesenting the gingiva ahitete apppiatey. eay if the iniian gives n infmatin t the tehniian, then the tehniian an ny gess the desied haateisatin f the gingivae - phtgaphs ae exeedingy sef.
As was mentined in Pat 8, we emmend that tw tia visits ae ganised, The fist visit, with the six ppe and six we antei teeth set-p enabes veifiatin f sa vetia dimensin (VD), P and the aeptabiity f bth bases fm thse aspets eating t mft, stabiity and the appeaane f the antei teeth. With these imptant aspets estabished, we wd age that it is easie, f bth iniian and tehniian, t nentate n detais eating t the fm f the teeth and as the gingivae. In essene, the tehniian shd ense that the gingiva ahitete satisfies f iteia.
* It shd be nvex ante-psteiy and spe-infeiy, t indiate a heathy appeaane, at the same time ensing a hygieni, sef-eaning fm.
* It shd have an hamnis aangement f heights f the gingivae; ideay the esent f the gingivae is highest in the midde f the ppe enta iniss, dps f the atea iniss and ises again f the ppe anines. The height f the gingiva esents f the ppe fist pema teeth shd be appximatey identia t thse f the ppe anines.
* The intedenta papiae shd demnstate a nata patten, ideay being ngest between the ppe enta inis teeth. The abve thee aspets ae shwn eay in Fige 6.
* The tehniian shd se denta fss t emve exess wax intedentay. At the tia dente stage, this meey efets n ak f attentin t detai by the tehniian; if n-ntied, it an est in dentes with p aestheti qaity (Fig. 7).
Tia dente visits
Thee ae f main aims f this visit:
* T veify that the appeaane f the dentes is satisfaty.
* T veify that the sa eqiements have been ahieved.
* T nfim that speeh has nt been advesey affeted by the fm f the epaement dentes.
* T deide n any eqiements f the dente base eg veined ayi, tansent ayi n the paate, staining, paement f estatins, et.
When these heks have been pefmed, and iniian and patient ae satisfied with the fm and fntin f the tia dentes, the tehniian may peed t pess the dentes.
Tehniian's bjetives
Pi t pepaatin f pessing, the tth aangement is eheked t ense n damage ed in tansit fm the iniian, and that n tth is se. Simiay, the waxwk in eatin t the teeth is heked t ense that eah tth is seey seaed in pae (this is anthe benefit f the se f nvex intedenta papiae).
The waxwk eating t the pished sfaes is as heked t ense it is we adapted t maintain the peiphea .
The sin and teeth ae dbe heked t ense n ateatin has ed t the sin - this shd be dne immediatey befe investing as sma hanges might if sizeabe ateatins wee made t the waxwk.
n the assmptin that the dente base is pymethymethayate (PMMA) and that the iniian has instted the tehniian n the speifis f the pyme, the tehniian wi invest the (dis-atiated) asts in the we haves f denta fasks.
The the haves f the fasks ae then sed t 'hd' the teeth t be sed in the dente, and the bk f stne investing these teeth is intended t minimise tth mvement ding paking and pessing f the dentes.
In essene, the pess f nveting wax tia dentes int mpeted dentes mpises tw stages and these invve emva f wax and epaing the wax with pyme dghptty whih is pessed nde pesse. The wax eiminatin pede ses ht wate t sften and emve the wax. Theeafte the tehniian has the ptin f sing ne f tw tehniqes t pess the PMMA.
The fist pess invves paement f the PMMA dgh manay int the fasks, effeting a tia se and then amping the fasks nde pesse and nted tempeate wate bath f the apppiate ing ye.
The send pede invves injetin mding f pe-pakaged dghptty, nde pesse int the fasks and the dentes ae then pessed nventinay. The pe-pakaged dgh has the advantage that the tehniian need nt hande the npessed mnme, a fat with heath and safety impiatins. The injeting eqipment is qite expensive, bt thee ae aims (as yet nsbstantiated) that the eve f esida mnme in the pessed dentes is ess than with nventina methds f pessing.
Fwing defasking, and peiminay efinement f any fashes n the dentes, the dentes and thei bases ae e-atiated and the sin stinised t see that:
* The inisa pin is sti n the tabe;
* Baaned sin is sti pesent in P;
* Baaned atiatin, if eqested is sti pesent n the atiat.
The dentes ae then emved fm the asts and the dentes timmed, pmied and pished t a high standad (Fig. 8).
Nte: The high pish shd nt be appied t the dente teeth as this wi eate an nnata appeaane.
At this stage, the tehniian shd have mpeted his invvement in the teatment ntat - ness pbems ditate thewise. These pbems wi be disssed in Pat 10.
Hepf Hints 1. Estabish a gd wking eatinship with y tehniian.
2. aify y design phisphies f asts, speia tays, et.
3. Take time t detai the pesiptin f eah dente - it enses that the detai eqied may be nfimed.
4. Enage the deivey f tia dentes n atiats - this enages attentin t detai f aestheti and fntina aspets.1Gides t Standads in Pstheti Dentisty. In A gden ed Gideines in Pstheti and Impant Dentisty ndn: Qintessene Pbishing td, pp 5-16.
Tabe 1 Minima eqiements f aeas t be eded in pimay impessins f mpete dentes
Fig. 1 Typia exampe f a gd qaity pimay ast eay demnstating the pimay and senday sppt aeas f the mandiba dente-beaing aea. By definitin, it is ve-extended in de that the extent f the speia tay may be taed apppiatey (indiated)
Fig. 2 1mm tin fi eief has been paed ve a ts paatins and the inisive papia t ede pbems f sppt pst-insetin
Fig. 3 Dena™ tansfe jig eates the bite-fk assemby t the atiat
Fig. 4 Gves n the ast faiitate emva and emnt via the spit-ast system. A simia mehanism is ahieved via the se f magnets t etain and ate asts
Fig. 5 The se f a tansent mnting tabe enabes the tehniian t assess the eatinship f the maxiay paata sps t the mandiba esida idge. The antei dak ine espnds t the tine f the ppe im. The aeas espnding t the mid-inisa pint and the anine pints have been maked
Fig. 6 Gd gingiva fm has been eated hee
Fig. 7 P gingiva fm and aeess wax nt has ested in a ess than aestheti est
Fig. 8 We pessed and pished mpete dentes