A new 3D-method to assess the inter implant dimensions in patients ? A pilot study

Complex implant treatments have steadily increased within implant prosthodontics. Based on the lower implant mobility, implant impressions need high accuracy in the model transfer to receive a high passive fit within the final prosthodontic restoration. To analyze the accurate 3-dimensional (3D) inter-implant-positions, a reference point is indispensable. However, there is no reference in the patients mouth, so the aim of the present study was to develop a new method based on a custom-made-measuring-aid (CMA) to assess the inter implant dimensions (InID) in patients. Initially an implant master model (IMM/patient equivalent) was digitized by computed tomography. A CMA was fixed on the impression posts and the inter implant dimensions (InID) were recorded with a coordinate measurement machine (CMM). For comparison to conventional and digital impression techniques, 10 impressions per technique were taken. InIDs for the IMM, the CMA and the two impression techniques were compared. To give a proof of principle, the new 3D-method was applied to three patients as pilot cases. Results for trueness and precision were analyzed by pairwise comparisons (p< .05). All data were subjected to univariate ANOVA. Mean deviation for InID ranged from 10.3±18?m(CMA) to 41.7±36?m(conventional). There were partially significant differences for InID between the CMA and the different impression techniques. There were no significant differences for InID within the CMA. The InID in the in-vivo evaluation ranged from 42.3?m to 376.7?m(digital) and from 58.3?m to 274.0?m(conventional). There were partially significant differences between the techniques. Within the limits of this study, with the developed method using a CMA it is possible to assess the true 3D-InID with a decisive higher accuracy than possible with a conventional or digital implant impression. Overall, the CMA in this study generated results that were deemed clinically useful for the investigated inter implant positions

Accuracy of Digital and Conventional Full-Arch Impressions in Patients: An Update

The aim of this clinical study was to update the available data in the literature regarding the transfer accuracy (trueness/precision) of four current intraoral scanners (IOS) equipped with the latest software versions and to compare these data with conventional impressions (CVI). A metallic reference aid served as a reference dataset. Four digital impressions (Trios3Cart, Trios3Pod, Trios4Pod, and Primescan) and one CVI were investigated in five patients. Scan data were analyzed using three-dimensional analysis software and conventional models using a coordinate measurement machine. The transfer accuracy between the reference aid and the impression methods were compared. Differences with p &lt; 0.05 were considered to be statistically significant. Overall, mean &plusmn; standard deviation (SD) transfer accuracy ranged from 24.6 &plusmn; 17.7 &micro;m (CVI) to 204.5 &plusmn; 182.1 &micro;m (Trios3Pod). The Primescan yielded the lowest deviation for digital impressions (33.8 &plusmn; 31.5 &micro;m), followed by Trios4Pod (65.2 &plusmn; 52.9 &micro;m), Trios3Cart (84.7 &plusmn; 120.3 &micro;m), and Trios3Pod. Within the limitations of this study, current IOS equipped with the latest software versions demonstrated less deviation for short-span distances compared with the conventional impression technique. However, for long-span distances, the conventional impression technique provided the lowest deviation. Overall, currently available IOS systems demonstrated improvement regarding transfer accuracy of full-arch scans in patients

Elastic deformation of the mandibular jaw revisited—a clinical comparison between digital and conventional impressions using a reference

Objectives!#!Due to the partly strongly differing results in the literature, the aim of the present study was to investigate a possible deformation of the mandible during mouth opening using an intraoral scanner (IOS) and a conventional impression for comparison with a reference aid.!##!Materials and methods!#!Four steel spheres were reversibly luted in the mandibular (n = 50) with a metallic reference aid at maximum mouth opening (MMO). Two digital impressions (Trios3), at MMO and at slightly mouth opening SMO and a conventional impression (Impregum), were taken as the measuring accuracy of the reference structure was already known. Difference between MMO-SMO for digital impressions and deviations between digital and conventional (SMO) were calculated. Furthermore, the angle between the normal vectors of two constructed planes was measured. Statistical analysis was performed with SPSS25.!##!Results!#!Deviations for linear distances ranged from -1 ± 3 μm up to 17 ± 78 μm (digital impressions, MMO-SMO), from 19 ± 16 μm up to 132 ± 90 μm (digital impressions, SMO), and from 28 ± 17 μm up to 60 ± 52 μm (conventional impressions, SMO). There were no significant differences for digital impressions (MMO-SMO), and there were significant differences between the conventional and digital impressions at SMO.!##!Conclusions!#!Based on the results of the present study, no mandibular deformation could be detected during mouth opening with regard to the digital impressions. The results were rather within the measuring tolerance of the intraoral scanner.!##!Clinical relevance!#!Based on the present study, no deformation of the mandibular during mouth opening could be observed at the level previously assumed. Therewith related, dental techniques related to a possible mandibular deformation therefore should be reconsidered

Development of a New Application-Based Chewing Efficiency Test (Mini Dental Assessment) and Its Evaluation by Nursing Staff in Geriatric Care: A Pilot Study

The increasing average life expectancy worldwide results in an elderly population with significant health care needs. However, dental care is often not a focus of care. It is well known that oral and overall health are directly related. Therefore, the Mini Dental Assessment (MDA) was developed to provide a simple analysis of oral health status, although it is currently only available in paper form, with all associated drawbacks, from illegible writing to the inability to quickly search the collected forms. This study aimed to develop a digital application (app) for mobile devices that can overcome the problems associated with paper forms. After the digital MDA was developed, its usability was evaluated by nurses, a questionnaire was answered, and it was compared to the analog MDA with patients in a pilot study. The usability of the app (System Usability Scale) was 95.18 ± 4.26, representing a very high usability. Furthermore, this app showed good clinical applicability. The results also showed that the digital MDA was accepted by nurses in their daily routine and was preferred to the analog MDA. A follow-up study with a higher number of subjects is highly recommended

Detailed non-destructive studies of prestressed bridgedecks under traffic conditions in the object-related damage analysis

Verkehrsbauwerke im Zuge von Bundesfernstraßen werden gemäß Stand der Technik nach DIN 1076 untersucht. Sofern bei der handnahen Prüfung Schäden festgestellt werden, deren Ursache und Umfang unklar sind, erfolgt die Durchführung einer objektbezogenen Schadensanalyse (OSA) nach dem Leitfaden der BASt. Zerstörungsfreie Prüfverfahren im Bauwesen (ZfPBau-Verfahren) werden bislang nur in geringem Umfang eingesetzt. Detaillierte Untersuchungen mit Bauwerkscannern werden im Rahmen der OSA bislang gar nicht eingesetzt. Die Aufgabenstellung dieses Forschungsvorhabens ist die Integration von ZfPBau-Verfahren in Form von Handmessungen und automatisierter Datenaufnahme mit Baustellenscannern in den Untersuchungsprozess nach DIN 1076 bzw. der nachfolgenden OSA. Das Gesamtziel bestand darin, die Leistungsfähigkeit von Bauwerkscannern für Prüfaufgaben im Rahmen der OSA zu verbessern und ihre Einsetzbarkeit praxisorientiert zu gestalten. Dies wurde an geeigneten Fragestellungen und Bauwerken gezeigt. Die Vorgehensweise, um den bestmöglichen Nutzen aus dem Einsatz des OSSCAR-Scanners zu erreichen, konzentriert sich auf die automatisierte Datenaufnahme und kombinierte Datenauswertung durch Vergleich von Radar, Ultraschall und Wirbelstrom. Um die automatisierte Datenaufnahme zu verbessern, wurden Geräteparameter wie Messpunktabstand, Messzeit an einem Punkt und Verfahrensgeschwindigkeit der Achsen den Bauteilbedingungen bestmöglich angepasst. Darüber hinaus wurde eine Strategie erarbeitet, die es erlaubt, Rüstzeit und Messzeit des Scanners zu verkürzen. Durch den Vergleich der Ergebnisse der Verfahren Radar, Ultraschall und Wirbelstrom, die auf der Basis von kongruenten Messflächen gewonnen wurden, ist der Mehrwert an Information hinsichtlich der inneren Konstruktion festgestellt worden.Traffic structures in connection with federal highways are examined according to state of the art to DIN 1076. If in hand close examination damage is found and their cause and extent are unclear, an object-related damage analysis (OSA) according to the Guideline of the Federal Highway Research Institute is conducted. Non-Destructive Testing in Civil Engineering (NDT-CE methods) have so far been used only to a limited extent. Detailed studies with on-site scanners are not yet used in the scope of OSA. The task of this research project was the integration of NDT-CE methods in the form of manual measurements and automated data acquisition with on-site scanners in the investigation process according to DIN 1076 or the following OSA. The general aim was to improve the performance of on-site scanners for testing tasks in the context of OSA and to make their applicability. The procedure to achieve the maximum benefit from the use of the on-site scanner OSSCAR, focuses on the automated data acquisition and combined data analysis for comparing radar, ultrasonic and eddy current methods. To improve the automated data acquisition, measurement parameter like measurement points distance, measurement time at one location and velocity of the scanner axis, were optimally adapted to the component conditions. In addition, a strategy has been developed, which allows to reduce set-up time and measurement time of the scanner. By combining the results of the methods radar, ultrasonic and eddy current, that have been obtained on the basis of congruent measuring surfaces, the added value of information regarding the internal structure has been achieved

Good role models? Tooth brushing capabilities of parents: a video observation study

Background: Research in adolescents reveals that they are not capable to remove dental plaque effectively. Inconsistent application of brushing techniques and neglect of certain areas while brushing are very common. As parents play a major role in the oral health education, the present study aimed to examine and describe the tooth brushing performance of the parents of adolescents. Methods: Parents of adolescents (N = 66) were asked to perform oral hygiene to the best of their capabilities in front of a video camera and dental plaque was recorded before and afterwards. Papillary bleeding was also assessed. Results: The tooth contact time (i.e. net brushing duration) averaged 155 s +/- 58 s. Gingival margins showed persistent plaque at 68% +/- 14% of the sections assessed. Papillary bleeding was found at 52% +/- 18% of the papillae. Parents brushed inner surfaces lesser than the outer surfaces (41 s +/- 24 s vs. 73 s +/- 33 s) and 29% of the parents completely missed the inner surfaces of at least one sextant. On the outer surfaces parents predominantly applied circular movements (66% +/- 25% of brushing time). Vertical brushing prevailed on the inner surfaces (52% +/- 30%). However, horizontal scrubbing was also very common (46% +/- 31%). Conclusions: Parents' tooth brushing performance was neither effective in terms of plaque removal nor did they fully comply with tooth brushing recommendations such as considering all inner surfaces when brushing or application of other than horizontal movements to lateral surfaces. Regarding oral hygiene, parents should not only be a good role model in terms of timing, frequency and duration of tooth brushing but should also be able to demonstrate how to brush teeth completely and effectively. The current research indicates that they might lack the latter skill

Accuracy of Digital Impression Taking with Intraoral Scanners and Fabrication of CAD/CAM Posts and Cores in a Fully Digital Workflow

Current intraoral scanners (IOS) enable direct impression taking for computer-aided de-sign/computer-aided manufacturing (CAD/CAM) posts and cores (P+C) with subsequent milling out of monolithic materials. The aim of this in vitro study was to systematically investigate the accuracy of CAD/CAM-P+C in a fully digital workflow, considering different IOS impression methods (Primescan (PRI), Trios4 without (TRI) and with scanpost (TRI+SP)) (Part A), and CAD/CAM milling of zirconium dioxid (ZIR) and resin composite (COM)-P+C (Part B). Five human models were developed in this study. Micro-CT imaging was used as a reference (REF). For Part A, the models were scanned 12 times for each impression method. Then, IOS datasets (n = 180) were superimposed with REF, and scan accuracy was determined using 3D software (GOMInspect). For Part B, one CAD/CAM-P+C (n = 30) was milled for each model, impression method, and material. The triple-scan method was applied using an industrial scanner (ATOS) to determine the accuracy of the fit. Statistical analysis was performed using analysis of variance (ANOVA, p &lt; 0.05). Part A showed for PRI significantly lower accuracy than TRI and TRI+SP (p &lt; 0.05). The data of Part B revealed significantly higher accuracy for ZIR than for COM (p &lt; 0.05). Within the limitations of this study, CAD/CAM-P+C of the ZIR can be recommended for fabrication in a fully digital workflow regarding the accuracy of fit

New Caries Diagnostic Tools in Intraoral Scanners: A Comparative In Vitro Study to Established Methods in Permanent and Primary Teeth

The aim of this in vitro study was to systematically investigate new caries diagnostic tools, including three intraoral scanners, and compare them to established diagnostic methods. For a standardized analysis of occlusal and proximal caries lesions, human permanent and primary teeth (n = 64) were embedded in models and investigated in a phantom head using six different caries diagnostic methods: visual examination, bitewing radiography, Diagnocam (KaVo, Biberach, Germany), Trios 4 (3Shape, Copenhagen, Denmark), iTero Element 5D (Align Technology, San José, CA, USA), and Planmeca Emerald S (Planmeca, Helsinki, Finland). The diagnostic methods were investigated and compared to reference µ-CT for permanent and primary teeth separately. For occlusal caries diagnostics in permanent teeth, the best agreement to the reference (reliability) was obtained for Planmeca Emerald S (ĸ = 0.700), whereas in primary teeth, for visual examination (ĸ = 0.927), followed by Trios 4 (ĸ = 0.579). Regarding proximal caries diagnostics, bitewing radiography, as the gold standard, exhibited the highest agreement for permanent (ĸ = 0.643) and primary teeth (ĸ = 0.871). Concerning the analysis of the diagnostic quality (sensitivity and specificity) using receiver operating characteristic (ROC) curve analysis, comparable findings were obtained for area under curve (AUC) values as for reliability. No diagnostic method could be identified that is generally suitable for occlusal and proximal lesions in both dentitions. Overall, caries diagnostics with intraoral scanners seem to be interesting tools that should be further investigated in clinical studies

Perspectives from Dentists, Dental Assistants, Students, and Patients on Dental Care Adapted to the COVID-19 Pandemic: A Cross-Sectional Survey

Dental care has been affected by SARS-CoV-2 (COVID-19) worldwide. In contrast to other dental clinics, the Justus-Liebig-University Giessen (Germany) decided not to limit dental treatment to emergencies alone, but to continue dental care for all patients, with increased safety measures. As such, health care professionals may be exposed to additional physical and mental stress. The aim of this study was to assess the perspectives of all persons involved in dental care (dentists, dental assistants, students, and patients) regarding the aspects of safety measures, anxiety about self-infection and infecting others, and other prospects in the period March to December 2020 using a questionnaire. Data collection was performed between 14 December 2020 and 23 January 2021. A total of 35 dentists (response rate of 79.5%), 23 dental assistants (65.7%), 84 students (80%), and 51 patients (21.8%) completed the survey. The patients did not notice any changes in the care received. Dentists and dental assistants reported a higher workload due to additional safety measures. The majority of dentists, students, and patients agreed that normal patient care was maintained. One-third of dental assistants would have preferred emergency treatment alone and expressed significantly higher anxiety about COVID-19 infection than all other groups (p &lt; 0.05). In conclusion, all groups showed a predominantly positive perspective on dental care, and anxiety about self-infection and infecting others was especially low. However, additional measures are time-consuming and compound daily patient care. This concept, based on well-established infection control, might be a viable proposal for current and future pandemics