Accuracy of intraoral real-time navigation versus static, CAD/CAM manufactured pilot drilling template in dental implant surgery – an in vitro study

Nach Zahnverlust gelingt heutzutage die Wiederherstellung des Kauapparates mit Implantaten zunehmend unterstützt durch dreidimensionale Planung und statische oder dynamische Hilfsmittel für den Transfer in die OP. Hierfür verwendete Bohrschablonen oder echtzeitnavigierende Systeme liefern verlässliche, präzise Ergebnisse, um durch die Implantation weder anatomische Strukturen des Patienten zu verletzen, noch das spätere Zahnersatzkonzept zu beeinträchtigen. Unsere Studie vergleicht die Genauigkeiten zwischen Pilotbohrschablonen, die den ersten Teil der Implantatbohrung unterstützen, und echtzeitnavigierter dynamischer Navigation mit dem DENACAM®-System der Firma mininavident. Die DENACAM® ist in ihrer Bauweise handlicher, als herkömmliche Systeme. Zwei Behandler mit unterschiedlicher klinischer Erfahrung haben an zwölf teilbezahnten Unterkiefermodellen aus Kunststoff insgesamt 60 Implantate gesetzt. Die prä- und postoperative Analyse erfolgte dabei durch digitale Volumentomographie. Zur Auswertung wurde das Treatment Evaluation Tool, eine in das Implantatplanungsprogramm coDiagnostiX® integrierte Software, genutzt. Im direkten Vergleich erhielten wir bei Nutzung der Bohrschablone signifikant genauere Ergebnisse im Versatz der Implantatbasis und -spitze in den einzelnen räumlichen Ebenen (p = 0,0079; 0,003; 0,0341; 0,0006; 0,0044). Hinsichtlich der Angulation war das Navigationssystem präziser (p = 0,0016). Die Differenz im Winkel zur Planung lag bei 3°. Die mediane horizontale Abweichung lag echtzeitnavigiert bei 0,52 mm an der Basis und 0,75 mm an der Spitze. Das Navigationssystem implantierte hinsichtlich der Angulation genauer, je näher die Bohrung am Erkennungsmarker des Systems lag (p = 0,0043). Die Bohrschablone zeigte diese Tendenz nicht und war den Winkel betrachtet präziser (p = 0,0022). Analog zur Literatur profitierten beide Behandler vor allem bei der Angulation des Implantats von der Echtzeitnavigation (p = 0,0337; 0,0355). Über die Versuchsdauer sahen wir lediglich eine subjektive Verbesserung der Implantationsleistung. Für zukünftige In-vivo-Untersuchungen könnte die Auswertung anstatt über ein postoperatives dreidimensionales Röntgenbild strahlenschonender mit digitalen intraoralen Scans durchgeführt werden. Für eine evidenzbasierte Empfehlung zur Anwendung des DENACAM®-Systems in vivo, sollten zusätzlich weitere klinische Studien folgen.Objectives: Nowadays, rehabilitation of the masticatory apparatus with implants is increasingly successful using 3D planning and static or dynamic aids. Aim of this study is to compare accuracy between pilot drilling templates and intraoral real-time dynamic navigation with DENACAM® system from mininavident. Methods: A total of 60 implants were placed on 12 partially edentulous lower jaw models by two practitioners with different clinical experience. One half were placed with pilot drilling templates, other half with dynamic navigation. In addition, implant placement in switching gaps and free-end situations was investigated. Accuracy was assessed by re-evaluation of postoperative cone-beam computed tomography. Results: In direct comparison, we obtained significantly more accurate results in offset of implant base and tip in particular spatial dimensions when using drilling templates (p = 0.0079; = 0.003; =0.0341; =0.0006; =0.0044). With regard to angulation, real-time navigation was more precise (p = 0.0016). Its inaccuracy was 3°. Median horizontal deviation was 0.52 mm at base and 0.75 mm at tip using DENACAM®. Regarding angulation, it was found that the closer the drill hole was to the system's marker, the better navigation performed. The template did not show this trend (p = 0.0043; = 0.0022). Analogous to the literature, both practitioners mainly benefited from real-time navigation regarding angulation of the implant (p = 0.0337; 0.0355). Over the trial period, we only saw a subjective improvement in implant placement performance. Conclusion: Considering limitations of an in-vitro study, dynamic navigation may be a tool for reliable and accurate implantation. At implant positions planned far from marker, inaccuracies should be expected and taken into consideration. However, further clinical studies need to follow in order to provide an evidence-based recommendation for use in-vivo. Clinical significance: The compact design of DENACAM® enables real-time navigation in practice.2021-08-3

Usinagem de próteses para cranioplastia a partir de imagens tomográficas

Orientador: Dalberto Dias da CostaDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Mecânica. Defesa: Curitiba, 2004Inclui bibliografiaResumo: A fabricação de próteses para substituição de tecidos duros (ossos) tem sido um tema recorrente em diversos trabalhos científicos na área de bioengenharia. Recentemente, com o avanço das técnicas de digitalização e processamento de imagens, vários pesquisadores vêm defendendo o implante de próteses pré-fabricadas como uma alternativa para redução do tempo de cirurgia, da morbidade, da dor pós-operatória, do risco de infecções e rejeições, além de apresentar melhores resultados estéticos. Dentre as alternativas para a fabricação de próteses sob medida, destaca-se o uso das tecnologias CAD (Computer-Aided Design), CAM (Computer-Aided Manufacturing) e CNC (Comando Numérico Computadorizado). Entretanto, existem ainda alguns obstáculos, no que se refere à integração da informação (imagens) obtida por tomografia aos sistemas CAD/CAM/CNC comerciais. O objetivo deste trabalho é apresentar e discutir duas diferentes abordagens para essa integração e mostrar os resultados da fabricação, por usinagem, de uma prótese para fins médicos. Várias imagens tomográficas de um crânio humano seco foram utilizadas como fonte primária de informação. Utilizando-se tanto softwares dedicados ao processamento de informações médicas como os de uso geral, para conversão e vetorização de imagens, foi reconstruída uma região de interesse do crânio digitalizado. Essa região modelada foi avaliada e depois convertida em um formato apropriado aos sistemas CAM’s, os quais permitiram a simulação e geração de um programa CN para a usinagem de uma possível prótese dessa região. Esta prótese foi fresada em acrílico e depois inspecionada visual e dimensionalmente. A principal conclusão deste trabalho é que a usinagem direta propicia excelentes resultados estéticos enquanto alternativa para a fabricação de implantes para cranioplastia. Palavras-chave: usinagem; superfícies complexas; imagens tomográficas; próteses sob medida; cranioplastia.ABSTRACT The use of prosthesis, for replacement of hard tissues (bones), has been a recurrent subject in a huge variety of scientific works in the field of bioengineering. Lately, with the advancement in digitalizing and image processing, researchers have pointed out the application of pre-fabricated implants as an alternative way for reduction of the time, morbidity, postsurgery pain, the risk of infections and rejections, besides presenting better aesthetic results. Among the alternatives for tailored prosthesis, the technologies CAD (Computer-Aided Design), CAM (Computer-Aided Manufacturing) and CNC (Computerized Numeric Control) are mandatory. However, there are still some difficulties concerning the integration of the information acquired from CT images to the commercial CAD/CAM/CNC systems. The purpose of this research is to present and discuss two differents methodologies for this integration and show the machining results of a milled PMMA prosthesis. Several CT images of a dry human skull were taken as primary source of information. Specialized medical softwares and general purpose systems, for image processing, were evaluated as a two methods for vetorizing and 3D reconstruction of a separated region from the CT images. The modeled region was evaluated and converted to readable CAM formats for machining simulation and NC code generation for a similar prosthesis. An acrilic blank was milled according to planed prosthesis and visualy inspected and measured. The main conclusion of this work is concerned to the good aesthetic results obtained by direct machining for cranioplasty. Keywords: Milling; sculptured surfaces; CT images; individual implants; cranioplasty

Guided surgery and immediate loading: A digital approach

Wismeyer, D. [Promotor