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Dental Tribune Middle East & Africa Edition | 6/2016 16 implant tribune Full-Arch Implant-Retained-Restoration. Fixed or Removable? By Prof. Gregor-Georg Zafiropoulos, UAE&Dr.ShahMaanas,UAE Dental implants as abutments for full-arch restorations are a widely accepted treatment modality. How- ever, when scheduling the use of a fixed or removable implant-sup- ported full-arch restoration, many factors should be considered. Due to the possible need for additional surgical steps to enhance the esthet- ics surrounding fixed restorations, removable implant-supported den- tures, often are a preferable alterna- tive. The current report presents a com- prehensive treatment approach, wherein the patient undergoes dif- ferent treatment modalities for res- toration of the upper and lower full arches at different timelines along with discussing the advantages and disadvantagesofeachapproach. Although implants have become a widelyacceptedtreatmentmodality, dentists and patients frequently are conflicted when deciding between a fixed or removable full-arch res- toration. Many patients requiring a full-arch rehabilitation, wish an esthetically sophisticated and fixed- implant-retained denture (FIRD). In suchcases,theestheticoutcomesare oftenseverelyrestrictedbyboneloss as a cause of advanced periodontitis and/ortoothextractions. Modern restorative materials and techniques make removable im- plant-retained-dentures (RIRD) to an esthetically and functionally accept- ablealternativetoFIRDs.1-4 A 55-year-old woman was referred for a complex periodontal-implant treatment(Fig.1,Fig.2).Duetosevere painteeth#18–16and14wereimme- diately extracted and the socket #14 was augmented using a non-resorb- ablemembrane(Cytoplast,Regentex GBR-200; Osteogenics Biomedical, Lubbock,TX).5,6 The patient was informed about the advanced bone destruction due to periodontitis and the following treatmentplanwererecommended: 1) extraction of the teeth # 13, 12, 22, 24, 14, 26, 36, and 32–42 due to ad- vanced chronic periodontitis as well as caries, and surgical treatment of the rest dentition by access flap surgery; 2) strategic placement of implants to increase the number of abutments; 3) full-arch restoration of the maxilla with a RIRD using tel- escopic crowns as attachments; 4) implant or teeth retained bridges for restorationofthemandible. The patient did not accept this pro- posal and sought treatment from anotherdentist. One year later, the patient presented again for consultation. Eleven im- plants have been placed (#12-15, 24, 25, 36-34, 45 and 46) and the max- illaandmandiblehavebeenrestored with FPDs at the patient’s request (Fig. 3 – Fig. 5). However, the patient was dissatisfied with the esthetic re- sults due to the unnatural length of the artificial teeth. Furthermore, the design of the existing FPDs impeded oralhygiene. Due to a home accident, the frac- tured teeth #11-23, 33, 43, and 44 were extracted and an implant was immediately placed in region #44. Open tray impressions were taken using a polyether impression mate- rial (Impregum Penta Soft, 3M ESPE) and mounted on a semi-adjustable articulator (SAM 2P, SAM Prazision- stechnik GmbH, Gauting, Germany). For an immediate restoration, pro- visional abutments were used and temporary covered dentures were fabricatedandretainedontheprovi- sionalabutments(Fig.6–Fig.8). Two months later, full mouth reha- bilitation of the maxilla (supported by six implants) and mandible (sup- ported by six implants) was com- pleted by fabrication of RIRDs using telescopic crowns as attachments, as previously described.7-9 Custom- ized abutments served as primary telescopes and electroformed pure gold copings (0.25 mm thickness, AGC Galvanogold, Au>99.9%, Wie- land Dental Systems Inc., Pforzheim, Germany) served as secondary tel- escopes (Fig. 9, Fig. 10). The metal frameworks was milled from tita- nium (Zenotec Ti, Wieland Dental Systems Inc., Pforzheim, Germany; Fig. 11) and veneered using a photo- curedindirectceramicpolymer(Cer- amage, Shofu, Ratingen, Germany; Fig.12–Fig.15). Discussion This report presents a case in which the patient was treated first with fixed restorations supported by im- plants and natural teeth and sub- sequently treated with an implant- retainedremovabledenture. Thepatientinitiallyinsistedonfixed restorations.Unfortunately,theden- tist fulfilled this wish, despite the existing clinical conditions of loss of hard and soft tissue. No augmenta- tive procedures were performed pri- ortoimplantplacement,resultingin a compromised treatment outcome. While the fixed restoration resulted in a functionally satisfactory treat- ment outcome, the patient was dis- pleased with the esthetic results. The main concern was the unnaturally long tooth shape necessary to com- pensate for the insufficient alveolar ridge height. The esthetic demands in such cases can be difficult to be fulfilled. Although several predict- able periodontal surgical procedures can be used to augment hard and softtissuetomeetestheticdemands, thepatientcouldrejecttheseoptions or the dentist might not be entirely familiar with the outcomes of these selected procedures. Both scenarios can produce unsatisfactory results that become apparent only when treatmentiscomplete. Replacementofthefixedrestoration with a removable one led to a more acceptableresult.Thetreatmentmo- dality of using telescopic crowns as attachments for natural teeth and dental implants for dentures has been proven successful for many years.8,9,10 This concept not only im- proves the retention form of the dentures due to frictional forces, but also improves the chewing ability for the patients. Other advantages of using telescopic crowns include feasibility for the patients to remove thedentureforperiodichygieneand maintenance; which is detrimental, particularly from a periodontal per- spective. Various other alternatives to restore edentulous arches include fixed as well as removable prostheses.10 With regards to availing the fixed option, clinicians routinely encoun- ter resorption of the alveolar ridges leading to atrophy along with loss of vertical dimension of the tissues, which in turn, pertains to placement of dental implants in unfavorable positions.Thiscanseverelyaffectthe prostheses by need for longer un- esthetic teeth as was the case in the presented report. Also, unfavorable positioningoftheimplantsmaylead to difficult access to the screw holes complicating the fabrication of pros- theses as well affecting the retriev- ability of the prostheses at the time ofmaintenancevisits. Other evident alternatives for RIRDs include use of bar-and clip retentive dentures. There are various reports suggesting soft tissue overgrowth in relation to the bar placed in these situations, hindering the long term oral hygiene regimen associated withthesedentures. Thecomplicationoffracturesrelated to frameworks’ veneering or one of theabutmentsinfixedaswellasbar- and-clipRIRDsisalsoreported.It,not only affects usability of the denture but also, adds an additional exorbi- tantexpenseandtimeconsumption for replacement, serves as a definite disadvantage while electing this al- ternative. In contrast to above mentioned shortcomings, ease of retrievability of telescopic crown supported RIRDs proves highly beneficial over other alternatives while overcoming the commonly encountered implant or natural teeth complications. Sev- eral complications related to dental implants range from implant-abut- ment screw loosening, peri-implant mucositis or peri-implantitis, or fracture of one of the used implants. Also, there is a potential risk of los- ing the used natural teeth abutment due to periodontal and/or endodon- tic/carious reasons that can affect the overdenture support. However, these circumstances can be evaded and continued usage of the telescop- ic crowns supported RIRD is possible with minor adjustments to the ex- isting prostheses without compro- mising long term success of these dentures. The case presented here raises the issue of whether dentists and/or surgeonsshouldjustfollowpatients’ wishesandexhaustallhigh-techsur- gical and augmentative possibilities or respecting periodontal principles should combine implant-prosthetic experience with evidence-based but less luxuriant surgical techniques. In manycircumstances,thelatterroute is a better and safer treatment alter- native. References 1. Dittmann B, Rammelsberg P. Sur- vival of abutment teeth used for telescopic abutment retainers in re- movable partial dentures. Int J Pros- thodont2008;21:319-321 2. Grossmann AC, Hassel AJ, Schilling O,LehmannF,KoobA,Rammelsberg P. Treatment with double crown- retained removable partial dentures Fig.1.Initialexamination.Orthopantomograph. Fig.5.2ndconsultation.Clinicalview(right). Fig.9.Customizedgoldimplant abutments. Fig.10.Fittingof theelectroformedcopings. Fig.11.Milled titaniumframework. Fig. 12. Final RIRD using telescopic crowns as attach- ment (front view). Fig.6.Orthopantomograph. Afterplacement ofimplant #44. Fig. 7. Provisional implant abutments and extraction sockets. Fig. 8. Temporary restorations retained on the provi- sionalimplant abutments. Fig.2.Initialexamination.Clinicalview. Fig. 3. 2nd consultation. Orthopantomograph. After implant placement andprosthetic treatment. Fig.4.2ndconsultation.Clinicalview(front). ÿPage 17