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ePaper created 2016-05-19, 12:42:25 | version 1.38.0
case report | 292 2016 implants brusheswereexplainedwithurgencybyadentalhy- gienist or a prophylaxis assistant. Discussion The patient came to our office with the desire for fixeddentures,whichcanbeachievedinmanydiffer- entwaysbyusingmoderntherapyconcepts.Remov- able dentures, which would ensure no disadvantage inrelationtodurability,aestheticsandhygiene,were rejected by the patient. We often experience well- informed patients, who specifically ask for full ceramic, zirconium or one-stage supplies. Therefore, it is very important to discuss all possible treatment options with the patient, because their knowledge often comes from unknown sources, and it can be unclear if they might have too high expectations on the final result. Foradentalprosthesiswhichisonlysupportedby implants, the jaw bone is the most significant in this context anatomically/physiologically. During the planning we orient ourselves first by the number of tooth roots to be replaced as the minimum number required,toavoidmoreboneresorptionandtosafely support the prosthetics. In the upper jaw, nine im- plantscouldbeplacedbilaterallyintheposteriorre- gion due to strong resorption to replace the total of usually24toothroots(17–27inacompletedentition inthemaxilla).Inthelowerjaw,twelveimplantswere insertedquantitytoreplacethe18toothrootsinfull dentition of 37–37 because of the better bone. Due to the patient who was from far abroad, we decided todoanall-in-onesurgicalprocedure,wherewere- move all remaining teeth, reconstruct the vertical and horizontal bone defects and insert implants. A two stage surgical procedure with implantation in a second appointment has no significant benefit in this case in our opinion. The interesting discussion about the advantages and disadvantages of both variantswouldgobeyondthescopeofthisprosthet- ically-oriented case demonstration. The biological behaviour of teeth and implants as a carrier of dentures differs fundamentally.12 Im- plants are ankylosed, teeth are connected with the bone by the periodontal ligament. The protective mechanoreceptive function,4 the better percep- tions of bite force10, 13 and the precise pain percep- tion10, 13 are lost with extraction of teeth and the as- sociated loss of the periodontal ligament. The tactility of the osseointegrated implant is set off by other sensors. Kineberg and Murray described this compensation in their study of 1999 as "Bone per- ception",6 which cannot achieve the tactility of the periodontium. This bone perception, as an alterna- tive feedback results from an interaction of recep- tors of the temporomandibular joints, skin, perios- teum and, in addition, of the mucosa by the use of mucosa carrying dentures. The tactility of im- plant-supported dentures is up to nine times less comparedtonaturalteeth.3, 4, 9, 10 Tominimisetherisk of overloading bite force by large implant-sup- porteddentures,teethshouldbemaintainedwhen- ever possible to obtain the periodontal feedback,12 which was not possible in the presented case. To reduce the risk of crestal bone resorption, screw loosening and fractures on the scaffold or veneer- ing3, 8 of the definitive zirconium/ceramic restaura- tionbyabnormalmasticatoryforcesinstaticanddy- namicocclusion,theplasticmock-upshouldbeworn to condition an alternative neural feedback. For im- plant impressions, we always use the pick-up tech- nique. This has the highest accuracy compared to the repositioning technique.1, 7, 14 As impression material, we prefer A-silicones rather than polyether because it tends to be more accurate due to its high hardness. In combination with the customisable foil Miratray® implant tray, the impression for purely implant-sup- porteddenturesiseasy,whichisconfirmedbystress- free incorporation in a rehearsal of the mock-ups. Performing large surgical/prosthetic restorations of the orofacial system requires close interdisciplinary cooperation between surgeon, prosthodontist, mas- ter dental technician as well as good compliance and resilience of the patient._ Editorial note: A list of references is available from thepublisher. contact OA Dr Björn Dziedo BERLIN KLINIK Department of Prosthodontics Leipziger Platz 3 10117 Berlin, Germany prothetik@berlin-klinik.de Fig. 8 Fig. 8: Final result after cementation. 2922016