Hintergrund: Obwohl der zahnmedizinische Behandlungsbedarf und damit der Bedarf an speziellen Therapieoptionen für Menschen mit Demenz zunimmt, gibt es nur wenige Forschungsarbeiten, die die Optimierung der zahnmedizinischen Versorgung dieser vulnerablen Klientel direkt adressieren. Dieser Artikel informiert über die Möglichkeiten und Chancen von partizipativen Forschungsprojekten im zahnmedizinischen Kontext und stellt ein partizipatives Studienprotokoll zur Analyse der Machbarkeit verschiedener Abformmethoden bei Personen mit fortgeschrittener Demenz vor. Methoden: Zunächst wurden Aufklärungs- und Einwilligungsdokumente in Leichter Sprache gemeinsam mit der Zielgruppe gestaltet. Im Studienteil werden der Vergleich der Durchführbarkeit von klassischen intraoralen Abformungen und intraoralen Scans bei Personen mit Demenz und die Messung des subjektiven Empfindungsniveaus (Proband/-in/Behandler/-in) während beider Interventionen angestrebt. Einschlusskriterien: Demenzdiagnose/Mini-Mental State Examination (MMSE) ≤ 24 Punkte, mindestens drei Restzähne im Oberkiefer, Einwilligung zur Teilnahme an der Studie. Nach Studieneinschluss erfolgt die Durchführung eines intraoralen Scans und einer konventionellen Abformung des Oberkiefers bei jeder/jedem Probanden/-in. Zur Quantifizierung des Komforts wird den Testpersonen unmittelbar nach jeder Abformtechnik eine visuelle Analogskala (VAS) vorgelegt. Zusätzlich erfolgt eine Qualitätsbewertung der Scans und Abformung im Experten/-innenkonsens. Registrierung der Studie: Deutsches Register für Klinische Studien: DRKS00027119 Ergebnisse: Dieser Artikel enthält eine Beschreibung neuer methodischer Ansätze zur partizipativen Forschung im zahnmedizinischen Kontext. Schlussfolgerung: Die Integration von Personen mit Behinderungen in zahnmedizinische Forschungsprojekte ist möglich und notwendig. Keywords: Abformungen, Demenz, Intraoralscans, Menschen mit Behinderungen, partizipative Forschung

Dieser Artikel beschreibt die mit dem demografischen Wandel einhergehenden Zukunftsaufgaben und klini-
schen Herausforderungen bei der restaurativen/prothetischen Rehabilitation von Senior/-innen mit reduzierter Therapiefähigkeit. In diesem Zusammenhang werden Möglichkeiten des digitalen Workflows auf der Basis von Intraoralscans zur Herstellung von Zahnersatz bei Patient/-innen mit reduzierter Therapiefähigkeit vorgestellt. Manuskripteingang: 09.03.2023, Manuskriptannahme: 14.04.2023 Keywords: Reduzierte Therapiefähigkeit, Senior/-innen mit Pflegegrad, Intraoralscan (IOS), restaurative Therapie

Titanium oral implants are still considered "state of the art" in implant dentistry, with well-documented survival rates. However, their grayish color and high prevalence of peri-implant infections have resulted in controversial discussion as to whether tooth-like-colored, metal-free zirconia ceramic implants provide sufficient potential to be considered equal regarding treatment outcomes. The present position paper has been composed upon invitation by the European Association of Osseointegration in order to provide an update on the current level of evidence regarding zirconia implants in clinical trials. To date, most available and scientifically documented zirconia implant systems are one-piece implants that require an experienced surgeon and prosthodontist due to the restricted flexibility in cases of compromised angulation or vertical positioning. Taking this limitation into account, there is evidence of a comparable outcome for one-piece zirconia implants compared to titanium implants for the fixed replacement of one to three missing teeth. In contrast, currently available clinical data evaluating two-piece zirconia implants with an adhesively bonded implant-abutment interface suggest an inferior outcome. Data evaluating the clinical applicability of screw-retained solutions, even if revealing sufficient fracture resistance in laboratory investigations, are still missing. High survival rates were reported for all-ceramic reconstructions supported by zirconia implants, but with increased technical complications; ie, fractures of the ceramic veneer in the case of bilayered restorations. Sufficient clinical evidence for recommending monolithic approaches is limited to single crowns.

Purpose: Creating wax-ups of missing teeth for backward planning in implant surgery is a complex and time-consuming process. To facilitate implant-planning procedures, the automatic generation of a virtual wax-up would be useful. In the present study, the reconstruction of missing teeth in partially edentulous patients was performed automatically using newly developed software. The accuracy was investigated in order to test its clinical applicability. Materials and methods: This study presents a new method for creating an automatic virtual wax-up, which could serve as a basic tool in modern implant-planning procedures. First, a statistical shape model (SSM) based on 76 maxillary and mandibular arch scans from dentally healthy individuals was generated. Then, artificially generated tooth gaps were reconstructed. The accuracy of the workflow was evaluated on a separate testing sample of 10 individuals with artificially created tooth gaps given as a median deviation, in millimeters. Scans of three clinical cases with partial edentulism were equally reconstructed using the SSM and compared with the final prosthodontic work. Results: The reconstruction of the artificial tooth gaps could be performed with the following median reconstruction accuracy: gap 21 with 0.15 mm; gap 27 with 0.20 mm; gap 34 with 0.22 mm: gap 36 with 0.22 mm; gaps 12 to 22 with 0.22 mm; gaps 34 to 36 with 0.22 mm. A scenario for an almost edentulous mandible with all teeth missing except teeth 33 and 43 could be reconstructed with a median reconstruction accuracy of 0.37 mm. The median tooth gap deviation of the SSM-based reconstruction in clinical cases differed from the final inserted prosthodontic teeth by 0.49 to 0.86 mm in median. Conclusion: A first feasibility of creating virtual wax-ups using an SSM could be shown. Artificially generated tooth gaps could be reconstructed close to the original with the proposed workflow. In the clinical cases, the SSM proposes an anatomical reconstruction, which does not yet consider prosthodontic aspects. To obtain clinical use, contact with antagonist teeth must be considered and more training data must be implemented. However, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined. (Int J Comput Dent 2022;25(4):349–0; doi: 10.3290/j.ijcd.b2599407) Keywords: statistical shape model, virtual wax-up, partial edentulism, accuracy, implant planning

Das Ziel dieser Übersichtsarbeit ist es, den Leser über die neuesten wissenschaftlichen Daten zu Zirkonoxidimplantaten zu informieren. In den letzten Jahren wurden zahlreiche Untersuchungen zur Stabilität, Osseointegration sowie zur (kurz- bis mittelfristigen) klinischen Bewährung veröffentlicht. Bewähren sich diese keramischen Implantate? Was sind Einflussgrößen, die auf die verschiedenen Aspekte oraler Implantate (Stabilität, Einheilung, Klinik) einwirken? Neuere systematische Übersichtsarbeiten zu präklinischen Untersuchungen zu Zirkonoxidimplantaten zeigten eine ausreichende Stabilität von einteiligen Implantaten mit einem Durchmesser von ≥ 4 mm für die klinische Anwendung. Zur Stabilität von zweiteiligen Implantaten sind nur wenige Untersuchungen zu finden. Bezüglich der Hart- und Weichgewebeintegration besteht kein Unterschied in der Hart- und Weichgewebeeinheilung zwischen Titan- und Zirkonoxidimplantaten mit vergleichbarer Oberflächentopografie. Die klinischen Kurzzeitdaten für einteilige Keramikimplantate sind vielversprechend und werden durch einige wenige Mittelzeitdaten bestätigt. Aufgrund der wenigen klinischen Daten zu zweiteiligen Implantaten kann über deren Erfolgsprognose noch nichts gesagt werden. Manuskripteingang: 16.10.2020, Annahme: 13.12.2020 Keywords: Zirkoniumdioxid, dentale Implantate, Osseointegration, Stabilität, Überlebensraten, Knochenverlust, in vitro, in vivo, Übersichtsarbeiten

The restoration of severely damaged teeth challenges dental practitioners because defects are often located at the subcrestal level. In these cases, surgical crown lengthening or orthodontic extrusion procedures are deemed necessary to maintain the biologic width and respect a sufficient ferrule design after preparation. Considering the negative effects of invasive surgical therapy—such as the reduction of alveolar bone support of the neighboring teeth—forced extrusion might be a valid therapeutic alternative. This clinical case report illustrates forced orthodontic extrusion with a minimally invasive appliance that is applicable in daily clinical routine.

Background: Accurate implant placement in the bone is key to successful implant treatment. Once inserted, it can be difficult to correct the orientation of the implant axis, especially of a one-piece implant. Prosthetic-driven digital implant planning in combination with fully guided implant surgery can offer additional safety in such cases. Case presentation: The patient presented with a wide, edentulous interdental space extending from sites 13 to 16, which was to be restored with three one-piece zirconia implants supporting a zirconia fixed partial denture comprizing a cantilever to the mesial aspect. Digital planning based on DICOM (Digital Imaging and Communications in Medicine) and intraoral surface data was performed to ensure optimal positioning. Guided implant placement was executed using a contra-angle handpiece with special attachments and a compatible, sleeveless drill guide. Impressions of the implants for the final restoration were acquired using an intraoral scanner. Reflection-related errors were compensated for by using the given digital abutment geometry. The DICOM and STL datasets were superimposed and used as the basis for fabricating a monolithic zirconia restoration through a subtractive milling process. The final restoration was adhesively cemented. Conclusions: By using a prosthetic-driven implant planning strategy, it was possible to place the one-piece ceramic implants without an available implant manufacturer's guide-based solution. This was accomplished using a contra-angle surgical handpiece with special attachments and a compatible drill guide. This approach is particularly recommended for the placement of one-piece implants, which otherwise require irreversible abutment grinding for the adjustment of the implant axis orientation after placement. To increase the precision of the digital impressions of the implants, the ideal abutment geometry was imported and superimposed onto the scan data. The results demonstrate that the proposed method can dispense with the need for gingival retraction when acquiring impressions for implants of this type in the future. Keywords: ceramic implants, guided implant surgery, backward planning, intraoral scan, CAD/CAM, digital workflow, 

Recent attempts in the development of novel zirconia ceramics aim at improving its optical characteristics by increasing the yttria content to up to 5 mol% so that these ceramics can be used for the fabrication of stable and esthetic monolithic restorations. However, clinical evidence on the outcomes of such restorations is sparse. In this case report, monolithic inlays, partial crowns, tooth- and implant-supported single crowns, and fixed dental prostheses were fabricated out of a zirconia ceramic doped with 5 mol% yttria. The restorations in the present case history report showed a satisfying esthetic outcome and are in situ as inserted 18 months after insertion.