implants - international magazine of oral implantology

clinical technique _ troubleshooting I treated dentally, or only with extreme difficulty, owing to unfavourable placement in the jaw- boneuntilthedentalmastermodelhasbeencre- ated by the dental technician after casting or af- ter the check-bite at the very latest. “Plaster is incorruptible!”. This conclusion, at- tributed to Freiburg dental surgeon Prof Eschler, was deliberately kept trivial; however, it is simply and utterly true. The dental master model shows the realities concerning placement of the im- plant, its axis, also with regard to abutment teeth, and the transition to the gingiva. _Exemplary patient cases Our report will demonstrate, based on a few exemplary patient cases, the solution possibili- ties, but also the limits of implant-prosthetic troubleshooting—especially in terms of achiev- ing a sustainable result for patient, dentist and dental technician. _Unidentified jaw misalignment (Figs. 1–8) The problem Two years ago, a male patient (in his mid-70s) had received two implants in the maxilla, fol- lowed by treatment with telescopes and a partial prosthesis. The patient stated that “the work did not agree with him right from the start”. Aside from functional problems, he disliked the fact that the maxillary front teeth were not visibleevenwhenheopenedhismouthhalf-way. Just by looking at the maxillary prosthesis it was easy to notice the metal portions of the pros- thesis, which were placed extremely palatinally, showingthrough.Anexaminationoftheoralcav- ity revealed a considerable discrepancy between the implant placement and the axis of the plastic front teeth! Our solution A wax-up marked the beginning of the actual treatment. It was modified until the patient was satisfied with the placement of his teeth and his subsequent appearance. Based on the results of this treatment planning, we were able to deter- mine which position and alignment would be re- quired for two additional implants (distally of the existing ones). This in turn resulted in the creation of a drilling template, which was used during the insertion of thetwoadditionalartificialabutmentteeth.After osseointegrationofthesetwoimplantsinregions #14 and 24, the new partial prosthesis (now sup- ported by four implants (two existing and two new ones) was produced and integrated step by step. Asidefromcasesliketheonementionedabove, which are usually the result of design errors and/or design flaws, there is additional, yet dif- ferent implant-prosthetic troubleshooting—cov- ering primarily implant fractures or failure of in- dividual implants within an extensive supra- structure. This considerably smaller part of im- plant-prosthetic problem areas, as compared with the group of design errors mentioned above, Figs.5&6_Afterinterdisciplinary planningbetweendentaltechnician anddentist,twoadditionaldistally locatedimplantswereinserted;the fourartificialabutmentteetheach receivedatelescopiccrown.Weused individualinsertionkeystofacilitate incorporationofthetelescopes. Fig.7_InitialX-rayimage(panoramic tomography)withtwoimplants (treatedwithtelescopes)inthe maxilla. Fig.8_Conditionaftertheincreaseof abutmentteethinthemaxilla,each inserteddistallyoftheprevious implants. Lossofimplantdueto peri-implantitis Fig.9_Themesialabutmenttoothofa bridgeentirelysupportedbyimplants intheleftmaxillawaslost.Afterheal- ingofthesofttissue,afurtherimplant wasinsertedinapositionascloseas possibletotheformerimplantposi- tion.Theillustrationshowsthedental mastermodelwiththecustomised abutment. Fig.10_Theformerbridgestructure wasusedasacustomised“spoon”for thenewlyaddedimplantsothata customisedabutmentcouldbe createdfortheadditionalimplanttobe mounteddistally(notethelossof verticaldistance)foruseinthe existingrestoration. I 27implants2_2011 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14