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Dental Tribune Middle East & Africa No. 4, 2016

Dental Tribune Middle East & Africa Edition | 4/2016 11 ÿPage12 Figures15a–15c:Thelabproducedwaxsetupsfortry-in.Theupperincludedtemporarycylinderssothesetupcouldbeattachedtotheimplantsduringevaluation.The lowersetupincludedrecesswellssoit couldbeseatedover theLocatorattachmentsandonto thesoft tissue. Figures16a–16c:Theupperand lower wax setups were tried in to evaluate fit, esthetics, occlu- sion and function per standard denture technique. Figures 10a, 10b: The patient returned 14 weeks after implant surgery, and healing of the peri-implant tissuehadprogressednicely. Figures 11a–11c:Transfer copings were attached to the maxillary multi-unit abutments, and an open-tray impres- sion was made to serve as the basis for the working cast the lab would use to begin designing the restoration. Note that aclosed-trayimpressionwas takenfor thelowerimplant overdenture. Figure 14: A VPS wash impression was made of the mandibulararch,capturingthepositionsoftheLoca- tor attachments as well as the gingival contours and vestibules. mCME ◊Page10 Figures 12a, 12b: For the recording of jaw relations, the lower wax rim was designed to seat over the Locator attachments,whileascrew-downwaxrimwascreatedfor theupper. Figures 13a, 13b:The upper wax rim was screwed into place through the temporary cylinders, while the lower wax rim was seated over Locator impression caps. The jaw relationship was recorded and a bite registration taken. the immediate placement of eight dental implants. CBCT scans were taken to help determine the optimal placement of the implants within the available bone and away from thepatient’svitaloralanatomy.Eval- uation of the CBCT scan determined that there was sufficient height, width and quality of bone to place theimplantsintheappropriateloca- tions and angulations via freehand surgery. Four 3.7 mm Inclusive® Ta- pered Implants (Glidewell Direct; Ir- vine, Calif.) would be placed in each arch to support the fixed maxillary restoration and the removable man- dibularprosthesis. At the surgical appointment, the patient’s remaining teeth were re- moved, and a flap was raised to vis- ualize the socket sites and areas of implantation. Bone leveling was per- formed on the patient’s maxillary arch to elevate the patient’s smile transitionlineabovetheupperlip. The maxillary osteotomies were positioned to facilitate an All-on-4 configuration, with the posterior implants tilted to maximize the an- terior-posterior (A-P) spread, avoid the sinuses, and accommodate the patient’s bone limitations (Fig. 3). Os- teotomieswerecreatedfortheplace- ment of four mandibular implants, as opposed to the minimum of two required for a Locator overdenture. This would enhance retention of the overdenturewhileaffordingthepos- sibility of upgrading to a fixed resto- rationatalatertime. Following creation of the osteoto- mies, the implants were placed (Figs. 4a–4c). Inclusive® Multi-Unit Abut- ments (Glidewell Direct) were at- tached to the maxillary implants, correcting for the divergent angula- tionoftheimplants.Thiswouldboth positiontherestorativeplatformina mannerthatwouldsituatethescrew access holes of the eventual prosthe- sis toward the lingual aspect and al- low for a molar-to-molar restoration (Fig.5). Note that when patients present for treatment with terminal dentition, they are commonly anxious about losing their teeth and the effect this will have on their speech and chew- ing capabilities. For this reason, it is important to make every effort to ensure that the patient leaves with functional appliances in place. Thus, traditional dentures were fabricated from preliminary impressions in ad- vance of the surgical appointment formodificationanddeliveryfollow- ing placement of the implants (Fig. 6). Having achieved sufficient primary stability, the Inclusive Tapered Im- plantsplacedinthepatient’smaxilla could be immediately loaded. Thus, the upper denture was trimmed and modified chairside to connect to the multi-unit abutments through tem- porary cylinders (Figs. 7a, 7b). This would satisfy the patient’s desire to leave the surgical appointment with a fixed, fully functional maxillary prosthesisinplace.Notethatthetwo distal-most molars were removed to minimize the cantilevers and the forces transmitted to the implants during osseointegration. Healing abutments were placed in the man- dibular implants to begin develop- ing the transmucosal passages. The lower immediate denture was then modifiedandrelinedtoseatoverthe implantsduringhealing. This approach provided the patient with same-day temporary restora- tions, and he walked out of the of- fice with properly functioning teeth for the first time in many years. The effect this had on the patient’s com- fort, function and appearance was immediate and profound (Figs. 8a, 8b). The final radiograph taken after seating the temporary appliances confirmed excellent positioning of theimplants(Fig.9). The patient returned after three and a half months of healing so the sta- bility of the implants and health of the soft tissue could be evaluated. Removal of the temporary applianc- es revealed excellent tissue health around the healing abutments of the mandible and multi-unit abut- ments of the maxilla (Figs. 10a, 10b). Vinyl polysiloxane (VPS) impres- sions were taken to begin the restor- ative process (Figs. 11a–11c). Because multi-unit abutments and healing abutments were placed on the day of surgery, the restorative process beganabovethetissuelevel,without any need for secondary surgery or anesthetization. The restorative protocol for both prostheses included wax rims and setups, which the lab produced on the working casts fabricated from the impressions (Figs. 12a, 12b). The maxillary wax rim incorporated temporary cylinders through which screws could connect to the dental implants. The lower wax rim was designed to seat over Locator attach- ments. At the next appointment, the wax rims were seated, the jaw relation- shipwasrecordedusingconvention- al denture technique, and a bite reg- istration was taken (Figs. 13a, 13b). A VPS “wash” impression of the man- dibular arch was also taken with the wax rims and Locator impression caps in place (Fig. 14). This would aid the lab in designing an overdenture that fully rests on the tissue instead oftheimplants. The case was returned to the lab, and waxsetupswereproduced(Figs.15a– 15c). During the try-in appointment, the wax setups were evaluated to confirm the vertical dimension of occlusion, interocclusal relationship, phonetics, esthetics, midline, teeth arrangement, tooth color and shape, incisaledges,andfunction(Figs.16a– 16c). After final approval of the wax set- ups, the restorative protocols for the two prostheses diverged, as the lab moved directly to the final implant overdenture from the approved wax setup, while the process for the BruxZirFull-ArchImplantProsthesis included an implant verification jig, custom final impression, and pro- visional implant prosthesis. These extra measures were taken to make absolutely certain that the defini- tive prosthetic design was accurate before milling the final restoration frommonolithiczirconia. The implant verification jig was at- tached to the implants so a precise finalimpressioncouldbetaken(Figs. 17a–17c). The custom tray provided by the lab was filled with VPS mate- rialandseatedovertheimplantveri- fication jig. As the VPS material set, therelativepositionsoftheimplants representedbytheverificationjigre- mained fixed, ensuring an extreme- lyaccuratefinalimpression. The approved wax setups and final maxillary impression were returned to the lab so the final mandibular implant overdenture and maxil- lary provisional implant prosthesis could be produced. The final lower appliancewasfabricatedonthemas- ter cast and included recess wells in whichmetalhousingswithoverden- ture caps would be cured chairside (Figs. 18a, 18b). These denture caps provide retention and stabilize the prosthesis by seating over the Loca- tor attachments and keeping the ap- plianceinplaceduringfunction. A new master cast of the maxilla was produced based on the custom open-tray final impression. The new master cast and final-approved wax setup were scanned. A virtual model was generated upon which the fixed monolithic prosthesis was designed using CAD software (Figs. 19a, 19b). Because this digital model was based on the final impression containing the verification jig, screw access holes were created in precise alignment with the positions of the maxillaryimplants. The CAD design was used to mill a provisional implant prosthesis from poly(methyl methacrylate) (PMMA) (Figs. 20a, 20b). This appliance was tried in and worn for a trial period, thusensuringanaccurateprosthetic design. The provisional implant prosthesis is an essential element of the restorative process, as significant adjustments cannot be made to the final restoration once it has been milledfromBruxZirSolidZirconia. At the following appointment, the Inclusive Locator Implant Over- denture was seated and checked for proper fit, function and sup- port from the soft tissue. Then the provisional implant prosthesis was screwedintoplace,anditsteethposi- tioning, function and esthetics were verified (Figs. 21a, 21b). With both ap- pliances in place, the interocclusal Dental Tribune Middle East & Africa Edition | 4/201611

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