Rapid developments in digital dentistry, such as digital workflows and CAD/CAM systems, have led to questions about digital occlusion, including the capabilities of occlusal analysis. There is a need for clear definitions and terminology. What do we mean when we talk about “occlusion” in the context of digitization, especially in the case of digital models? What are the capabilities of digital occlusal analysis? The following article presents our initial thoughts on this important topic, which may be useful in the development of future guideline. Parole chiave: digital occlusion, digital occlusion analysis, virtual articulator, digital articulator, digital patient, digital functionally generated path technique (FGP technique)

Angesichts rasanter Entwicklungen im digitalen zahnmedizinischen Bereich (wie digitaler Workflow und CAD/CAM-Prozessabläufe) stellen sich Fragen zur digitalen Okklusion einschließlich der Möglichkeiten der okklusalen Analyse. Hierbei drängen sich Gedanken zu Definitionen und Begriffsbestimmungen auf: Was meinen wir, wenn wir im Kontext der Digitalisierung speziell bei digitalen Modellen von Okklusion sprechen und welche Potenziale ergeben sich bei einer digitalen Okklusionsanalyse? Erste Überlegungen zu diesem wichtigen Thema sollen nachfolgend vorgestellt werden, die in eine spätere Leitlinie einfließen könnten. (Der Entwurf eines Positionspapiers wurde im Rahmen der DGFDT-Jahrestagung im November 2023 in Bad Homburg vorgestellt und diskutiert. Zusätzlich wurde die vorgestellte Textfassung an weitere Expertinnen und Experten zur Kommentierung übersandt. Die Ergebnisse der Diskussion und der Kommentierung wurden in das vorliegende Positionspapier eingearbeitet.) Parole chiave: digitale Okklusion, digitale Okklusionsanalyse, virtueller Artikulator, digitaler Patient, Digitale Functionally-Generated-Path-Technik (FGP-Technik)

Aim: To test four different measurement methods to evaluate deviations between planned and actual implant positions within a digital workflow applying 3D-printed surgical guides. Materials and methods: A fully digital workflow was applied to simulate the single implant insertion to replace a maxillary missing central incisor and first molar in 10 gypsum casts (n = 10). Surgical guides (n = 10 per site) were printed by digital light processing for implant bed preparation and implant insertion. Four methods were used to analyze 3D deviations between the planned (target) and achieved implant positions: Methods 1 and 2 used an automated computer program (ACP) to assess deviations between the initial planning file and a file that represented the actual implant position either by the implant bed [ACP_BED] or by the inserted implant [ACP_IMP]. For Method 3, a standard tessellation language dataset representing the actual implant position was used and equipped with reference planes. This dataset was registered with the target planning, allowing manual measurements [MAN_MEAS]. Method 4 used a reverse engineering approach based on 3D high-resolution scans [REVERSE]. Results: Mean 3D deviations, including for anterior and posterior implant sites, ranged between 0.26 ± 0.11 mm [REVERSE] and 0.40 ± 0.09 mm [ACP_BED] at the implant shoulder, between 0.52 ± 0.24 mm [REVERSE] and 0.91 ± 0.24 mm [ACP_BED] at the implant apex, and between 1.68 and 2.35 degrees in angular deviation. Implant sites did not differ significantly, while some of the evaluation methods differed for shoulder and apex. Conclusion: [REVERSE] revealed the smallest deviations between planned and actual implant position. 3D implant deviations were comparable with findings in the literature or even lower. Parole chiave: digital light processing (DLP), 3D printing, static computer-aided implant surgery (s-CAIS), implant surgical guides, accuracy, trueness, evaluation methods

An increasing number of accuracy studies on 3D digitizing systems, especially intraoral scanning devices, are being published in scientific and educational journals. The methods, measurement values, and statistical parameters of these studies vary. Certain inconsistencies exist, which lead to difficulty in terms of interpretation and sometimes even questionable conclusions being drawn. These issues make it almost impossible to compare the results of such studies. One aspect inherent in this is the mutable use of basic terms describing the quality of measurement outcomes. A clear definition of such terms and clear instructions as to their respective calculation processes is essential for communication among scientists as well as for reporting measurement results to the dental community. Therefore, the aim of the present guideline is to provide a clear definition of the accuracy, trueness, and precision as the basic terms in the context of digital dentistry. The survey for this guideline included the application of ISO Norms and their expansion to special aspects concerning 3D data acquisition and, in particular, surface meshes. Additionally, the literature was screened to collect approaches, which can be seen as useful for dealing with these terms when performing different kinds of studies. Parole chiave: intraoral scanning, accuracy, precision, trueness, ISO standard, 3D evaluation

Das Ziel dieser Studie bestand in der Evaluation der klinischen Qualität und Langzeitstabilität von chairside-hergestellten Lithiumdisilikatkeramikkronen nach 10 Jahren. Parole chiave: Digitalisierung, Langlebigkeit, Vollkeramik, monolithische Kronen

Die vorliegende Untersuchung beschreibt einen modellfreien chairside-Workflow, der die Herstellung von monolithischen Restaurationen auf individualisierten Abutments mit subgingivaler Präparationsgrenze ohne periimplantäres Weichgewebemanagement ermöglicht. Dem Anwender wird eine einfach anwendbare Checkliste für die Individualisierung von Standard-Abutments an die Hand gegeben, sodass die Form des Abutments mit einer speziell entwickelten Software nach der optischen Abformung kompatibel ist. Die Methode beinhaltet sowohl eine extraorale Abformung der Präparationsgrenze des Abutments als auch eine intraorale Abformung, die die Position des Abutments in Relation zu den benachbarten Zähnen wiedergibt. Die Software, die für die halbautomatische Registrierung der intraoralen und extraoralen optischen Aufnahme notwendig ist, verarbeitet stl. Datensätze und kann auf Anfrage von den Autoren zur Verfügung gestellt werden. Parole chiave: individualisierte Abutments, chairside, modellfrei, Registrierung, intraoral, Scanner, Software, Präparationsgrenze

In einer früheren Publikation wurde ein ausschließlich digitales Konzept zur Ebenenrekonstruktion bei verloren gegangener Kauebene im Verschleißgebiss vorgestellt. Hierfür war aber ein Facescan unabdingbar. Da dieser aber weniger verfügbar ist als ein Gesichtsbogen, stellt die aktuelle Konzeptbeschreibung eine Kombination analoger und digitaler Techniken vor. Dabei wird dem Problem der Neudefinition der Kauebene bei Bisslageänderung Rechnung getragen und die digitale Konstruktion der Kauflächen bei der chairside Behandlung im "luftleeren" Raum vermieden. Letzteres ist insbesondere eine Gefahr, wenn die Indikation zur Bisshebung sowohl in Ober- als auch in Unterkiefer besteht. Parole chiave: vertikale Relation, Bisshebung, chairside, CAD/CAM, Ebenen, Gesichtsbogen, alternierend, Keramik, Komposit

Aim: The aim of this in vivo study was to measure antagonist wear caused by polished monolithic posterior zirconia crowns over a 24-month period using the intraoral digital impression (IDI) technique. Materials and methods: Thirteen zirconia crowns were placed in nine patients. The crowns and adjacent teeth were captured using an intraoral scanner (Lava C.O.S.). The corresponding antagonist teeth and the respective neighboring teeth were also scanned. Scanning was performed immediately after the restoration (baseline) as well as 12 and 24 months after crown placement. Geomagic Qualify software was used to superimpose the follow-up data sets onto the corresponding baseline data set, identify wear sites, and measure maximum vertical height loss in each individual wear site. Overall antagonist wear was then determined as the mean of wear rates measured in all of the individual antagonist units. In addition, wear rates in enamel and ceramic antagonists were analyzed as part of the scope of this study. Results: The maximum mean wear with standard deviation (SD) in the overall sample with a total of nine patients, 13 antagonist units, and 98 evaluable wear sites was 86 ± 23 µm at 12 months, and 103 ± 39 µm at 24 months. The maximum mean wear in the enamel antagonist subgroup was 87 ± 41 µm at 12 months, and 115 ± 71 µm at 24 months; and in the ceramic antagonist subgroup 107 ± 22 µm at 12 months, and 120 ± 27 µm at 24 months. Conclusions: The wear rates determined in this study are comparable to those of existing studies. The IDI technique of wear analysis can be carried out in a practical manner and produces useful results. Parole chiave: wear, zirconia, monolithic, antagonist, clinical, digital, intraoral scan