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Dental Tribune Middle East & Africa Edition No. 5, 2015

36 Dental Tribune Middle East & Africa Edition | September-October 2015implant tribune < Page 35 Fig. 1: Esthetic evaluation prior to commencing the treatment: an edentulous upper jaw had been provided with a conventional complete denture. Fig. 6: Try-in of the wax setup and evaluation of the esthetic parameters Figs 2 and 3: Following the healing and osseointegration process of four implants, an impression of the oral situation was taken. The impression posts were splinted together prior to impression taking. Fig. 4: Implant model for the reconstruction of the overdenture Fig. 5: The models mounted on the articulator clearly demonstrate the challenges involved in this clinical case. Fig. 7: Customized titanium abutments Fig. 8: Reconstruction of the primary structure after scanning the model, abutments and setup Figs 9 and 10: Grinding and smoothing of the primary structure made from zirconia in a milling unit using CAD/CAM technology Fig. 11: Intraoral bonding of the galvanoformed secondary structure with the tertiary structure Fig. 15: Implant-retained overdenture inserted in the patient’s mouth Figs 12 and 13: Detailed view of the completed denture: customized prefabricated teeth and soft tissue parts Fig. 14: The macro-texture and shade ef- fect of the denture were individualized in a straightforward manner to achieve a result that is true to nature. Abutment). Next, the zirconia telescopes were adjusted using a lab turbine and parallelograph. The walls of the telescopes were given a 2° incline and smoothed out using appropriate diamond grinding tools and sufficient wa- ter cooling (Figs 9 and 10). Secondary structure The primary crowns could now be prepared for the manufac- ture of the secondary crowns by means of the galvanoforming technique. For this purpose, the zirconia surfaces were covered in a thin coating of conductive silver using the airbrush method and the galvanoforming process was commenced. Upon completion of the gal- vanoforming process, the gal- vanized gold crowns were de- tached from the telescopes and the conductive silver coating was removed with a nitric acid containing solution. In the pro- cess, a highly accurate second- ary structure was obtained. Tertiary structure All the components were reposi- tioned onto the working model. Before the tertiary structure was fabricated, the galvanofor- med crowns were covered in a thin layer of wax to create the space necessary for the cement that would later be used. The tertiary structure was invested, cast in CoCr alloy using induc- tion casting technology and then finished. The tertiary structure was intraorally cemented onto the galvanoformed telescopes (Multilink Hybrid Abutment, Monobond®) in order to obtain a tension-free restoration (Fig. 11). Esthetic design The structure thus obtained was covered in opaque light-curing lab composite (SR Nexco®) in pink and white prior to finish- ing the prosthesis. The silicone key was again used as a guide: the Phonares II teeth were re- positioned from the wax setup to the framework. The occlusal parameters were again checked and then we proceeded to com- plete the restoration. To reconstruct the pink gingival portion, we used the IvoBase® injection system. First, the den- ture was invested in two espe- cially designed flask halves us- ing type III and IV plaster. After removing the wax and isolat- ing the plaster surfaces, we pre pared an IvoBase capsule and placed it together with the flask into the polymerization cham- ber. The IvoBase injection and polymerization process is fully automated and takes about 60 minutes. Users can choose be- tween two program options: Running the standard program takes about 40 minutes. If the RMR program is additionally activated, the pressing time in- creases, as a result of which the monomer concentration is reduced to less than one per cent. This aspect is beneficial to patients because the risk for allergies and irritations of the mucous membrane is virtually eliminated. Upon completion of the injec- tion program, the flask halves were opened, the denture di- vested from the stone core and processed with milling and pol- ishing instruments. In an effort to create a tooth replacement that closely meets the expecta- tions of the patient, we decided to customize the visible areas of the denture by applying ad- ditional material (SR Nexco). To this end, the vestibular sur- faces of the anterior teeth and the corresponding pink parts were sandblasted. SR® Connect was applied and the teeth and prosthetic gingiva were char- acterized with SR Nexco and the shape adjusted according to the requirements of the patient. Final polishing was carried out with biaxial brushes and pads. This procedure yielded a result that was true to nature and ad- justed to the specific require- ments of the patient (Figs 12 to 15). Conclusion Many patients respond with reluctance to the idea of being given removable dentures. If dentures are optimized by add- ing the stability of implants and the effectiveness of telescopes, dental professionals will be able to dispel the initial reservations of their patients and offer them a tooth replacement that provides the expected level of comfort. Completely edentulous patients have the same high esthetic expectations as patients requir- ing fixed restorations. However, some of these requirements are more difficult to satisfy in the edentulous patient, because we are forced to replace not only missing teeth but often also soft tissues. To achieve this, we need to find a way of creat- ing harmony between the pink and white aspects of the den- ture. Today‘s patients tend to be well informed. They place ever higher expectations on the esthetic and functional aspects of tooth replacements. Against such a background, we need to be well trained and know which materials and technologies can ease our job and increase our efficiency. This will enable us to solve any clinical case, regard- less of its difficulty. Cristian Petri, CDT Laborator Dentar Artchrys Govora 8 400664 Cluj-Napoca Romania office@artchrys.ro www.artchrys.ro Contact Information

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