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ePaper created 2016-05-19, 12:42:25 | version 1.38.0
case report | 272 2016 implants (Aesthetic) Fitting Forlargecircularfixedrestorations,afullysculpted mock-up was made of model plastic in the desired tooth colour and possible tooth shape (Figs. 3a–c). This prosthetic feature served as a trial run, as a qualitytransitionandarehabilitationsupply(“PÜR”- mock-up Berlin clinic model, Figs. 3a–c) and was originally developed by us specifically for extensive supplies, cases of this kind, and cases with total atrophic alveolar ridges so we could check the fit, the bite and aesthetic wishes of the patient for the future dentures. In this step, zirconium is not yet milled. If the mock- up does not fit, a second check-up impression can be madesimplyviatheindividualimplantabutmentsfor theproductionofanewmodelforthemastertechni- cian.Theabutmentswerescrewedinwith20 N/cmin accordance to the agreement with the master dental technician and the manufacturer. The seat of the abutments would be evaluated after transferring by using a transfer key on the panoramic X-ray (Fig. 1d). Themock-upwasusedfortheaestheticcheckbefore the ceramic is made. Tooth colour, teeth shape and placing give the patients a real idea about the result. Change requests can easily be modified in the plastic denture. Furthermore, and most importantly for the patients’requirements,the“PÜR”-mock-upservesto hold off the moveable soft tissue, avoiding any need of a repeated exposure of the implants from the newly-growntissueinthedistallowerjawunderlocal anaesthesia. Thenextstepwastheevaluationoftheparallelism oftheocclusalplanewiththecamper'splaneandthe bipupillary line using the Candulor bite fork (Ameri- can Dental Systems®, Figs. 4a & b). The mock-up was supplied with a registry plate made in the labo- ratory (Figs. 3a–c). After successful try-in and aes- theticfitting,thefunctionaljawmovementregistra- tion via supporting pin registry was done (Fig. 3b) with subsequent bite encryption by registration sili- cone (Fig. 3c). In the present case, the patient had found his habitual occlusal position. If he had not done so, we would have performed an additional temporomandibular joint movement registration using software-supported evaluation (zebris JMA system). In the laboratory, the zirconium framework was milled and the veneering ceramics were applied ac- cordingtothewishofthepatient.Thus,thenextstep wasthetry-inofthebisqueceramic,whichwasmade two days later (Figs. 5a & b). Usually, we advise a fewdaystestingtimeforthepatienttogiveusafeed- back about aesthetics and function of the “PÜR”- mock-up. Due to the quite large phenotypic changes ofpatients,thetestingperiodisbothpsychologically and functionally informative. The mock-up also serves as temporary denture and the patient can “practise” his new bite situation. From our point of view,thisstepsignificantlyreducestheriskofceram- ics chipping by habitual improper load or measures sensation induced malocclusion of definitive resto- rations. By the exclusively implant-supported tooth replacement, the neural feedback of the periodon- tium is missing. The absence of tactility specifically increases the risk of fracture of ceramic and can lead totraumataofthehardandsofttissuetogetherwith pain sensations. Since the patient comes from abroadandwantedtobesuppliedassoonaspossible, thetestingperiodwasskipped,whichwasacceptable due to the good compliance and uncomplicated occlusal conditions of the patient. Practicing the newbiteandeducationaboutthenecessityofcareful biting in the first days after placing the dentures werethereforeimportantandcrucialforthesuccess of the treatment. Bisque ceramic try-in The information supplied by the mock-up was then incorporated into the planning of the zirconium/ ceramicworkandimplementedbythedentaltechni- cian.Thedata,whichhadalreadybeenenteredtothe computer by model scan, were now transmitted to the CNC 5-axis milling machine (Zenotec select hy- brid,WielandDental),andmilledfromasolidzirconia blank,minusthespacefortheveneeringceramicthat would be topped up manually by the master dental technician. Fig. 5a: Bisque ceramic in articulator. Fig. 5b: Bisque ceramic in vivo. Fig. 5bFig. 5a 2722016