Clinical performance of monolithic lithium disilicate hybrid abutment crowns over at least 3.5 years.

PURPOSE: Hybrid abutment crowns (HACs) made from monolithic ceramics represent an efficient option for single restorations on implants. However, long-term data are scarce. The purpose of this clinical trial was to evaluate the survival and complication rates of CAD-CAM fabricated HACs over a time period of at least 3.5 years. MATERIALS AND METHODS: Twenty-five patients with a total of 40 HACs made of monolithic lithium disilicate ceramic bonded to a titanium base CAD-CAM abutment were retrospectively evaluated. All implants and screw-retained restorations were placed and manufactured in the same department of a university hospital. Only crowns that had been in service for more than 3.5 years were included in the study. HACs were evaluated regarding technical and biological complications. Functional Implant Prosthodontic Scores (FIPS) were obtained. RESULTS: The mean observation time was 5.9 ± 1.4 years. Implant survival was 100%, and HAC survival was 97.5%. Over the observation period, one crown fracture was observed, necessitating refabricating of the restoration. Three minor biological complications were found. The overall mean FIPS score was 8.69 ± 1.12 points. CONCLUSIONS: Within the limitations of this study, monolithic screw-retained HACs milled from lithium disilicate ceramics and bonded to titanium bases appeared to be a reliable treatment option over more than 3.5 years due to their low biological and technical complication rates.

Correlation between theoretical knowledge and the difference between self- and teaching doctor-assessment.

OBJECTIVES: The right intuition for self-assessment without overestimating or underestimating oneself compared to theoretical knowledge is a skill that requires conscious practice and is very often paradoxically opposed to the level of knowledge. Self-assessment is an essential skill for dental professionals for lifelong learning and improvement. The objective of our study was to assess the correlation between theoretical knowledge and the difference between self- and teaching doctor-assessment. METHODS: The app "digital course organizer" for organization and assessment was used for the self- and teaching doctor-assessment of students for each day of patient treatment during the clinical courses at a university hospital. The difference between the self- and teaching doctor-assessment was compared to the score of an initial theoretical written test at the beginning of the eighth semester to assess the correlation between overestimation or underestimation and theoretical knowledge. RESULTS: A total of 309 dental students over four semesters in the clinical study phase (fourth and fifth years; eighth and 10th semesters) participated in the investigation. The overall view of all values showed very low correlations (<0.2) of the assessment difference values of both practical courses for the initial written test. CONCLUSION: There were very low correlations between the initial written test (theoretical knowledge) and the difference between self- and teaching doctor-assessment as well as no evidence of overestimation and underestimation.

Digital jaw relation recording to evaluate a new vertical dimension of occlusion using CAD/CAM-fabricated tooth-colored splints: a case report.

Pronounced defects of the dental hard tissue can be caused by different etiologic factors. Most frequently, they are associated with changes in the vertical dimension of occlusion (VDO), which may also influence the condylar positions. These defects can lead to irreversible loss of tooth structure and have dramatic functional and esthetic consequences, often requiring complex rehabilitation. In this situation, CAD/CAM-fabricated occlusal splints made of tooth-colored polycarbonate are a proven and safe pretreatment approach in terms of esthetics and function. Rebuilding lost dental hard tissue to restore the occlusion and VDO to an adequate condylar position is a prerequisite for any sustainable and functional rehabilitation. In the future, digital systems will support this complex process, customizing it and making it simpler and more precise. The DMD-System (Ignident) provides patient-specific jaw movement data to optimize the CAD/CAM workflow. This system allows real movement patterns to be digitized and analyzed for functional and potential therapeutic purposes, integrating them into the dental and laboratory workflow. In the present case, the familiar tooth-colored CAD/CAM-fabricated occlusal splint is supplemented by digital centric jaw relation recording and individual movement data.

First evaluation of an app to optimize and organize the processes and assessments in dental clinical courses.

BACKGROUND: Digital teaching and learning tools, such as computer/mobile apps, are becoming an important factor in modern university education. The objective of our study was to introduce, analyze, and assess an organization and dual assessment app for clinical courses in dental medicine. METHODS: This was a survey-based study of dental students from the clinical study phase (4th/5th year; 8th/10th semester) of a department of prosthetic dentistry at a German university hospital about the benefits of a novel web-based and mobile app for organization and dual assessment of dental clinical courses. A total of eight questions were answered in an anonymous online survey. Data were analyzed using the Kolmogorov-Smirnov test, followed by an exploratory data analysis (α < 0.05). RESULTS: The app was given an average grade of 2.4, whereby 56.9% of the respondents rated the app with a grade of 2 (2 = good). In all, 94.6% of the study participants had not experienced any technical problems when using the app. Concerning the assessment, teaching doctor assessment (51.5 [IQR: 44.0]) was rated significantly better (p = 0.002) than self-assessment (39.5 [IQR: 32.8]). CONCLUSIONS: This investigation evaluated a newly introduced app to optimize dental clinical course workflows and assessment. The organizational feature was rated as good, while the daily self- and teaching doctor assessments were evaluated as less important. The results outline how the use of app technologies can provide an infrastructure for managing organization and daily assessments in dental education.

Dental education during the pandemic: Cross-sectional evaluation of four different teaching concepts.

OBJECTIVES: To evaluate the advantages of student satisfaction with and functionality of three digital teaching concepts during the SARS-CoV-2 pandemic compared to a conventional lecture setup. METHODS: This cross-sectional study was a survey-based e-learning research among dental students in the clinical study phase of a department of prosthetic dentistry at a German university hospital. A total of 44 questions were answered in four main sections: 1. general technical components; 2. acceptance; 3. evaluation and functionality; and 4. overall evaluation and grades of the various digital concepts. The use of Zoom conference, livestream, and prerecorded PowerPoint was compared to the conventional lecture setup (control group/CG). Data were analyzed using the Kolmogorov-Smirnov test, followed by an exploratory data analysis and Cronbach's alpha test (α = 0.05). RESULTS: Students were very satisfied with the provision, quality, and benefit of the digital concepts. The asynchronous concept was significantly more satisfying than the synchronous concepts in many aspects but was less successful in interactions. In the overall evaluation and grading, the asynchronous concept was rated significantly better than the other synchronous concepts (p ≤ 0.007), followed by Zoom conference, conventional lecture (CG), and livestream, while Zoom conference and the conventional lecture showed no significant difference (p = 0.784). CONCLUSIONS: Students significantly preferred the asynchronous concept to the synchronous concepts. The results suggested that asynchronous concepts are an effective and functional form of distance education during a pandemic. In general, digital teaching concepts are currently widely accepted for maintaining university education.

Reproducibility of a magnet-based jaw motion analysis system.

BACKGROUND: The Dental Motion Decoder system (DMS-System) is a medical device based on magnetic field technology that records mandible movements. The data can be used to program an articulator or can be directly processed over a computer-aided design (CAD) interface. The present study aimed to assess the reproducibility of this system in vitro and in vivo. MATERIAL AND METHODS: Protrusive and laterotrusive movements were simulated in vitro using an articulator (SAM SE) (Group M) and in vivo (Group P) on one test individual. Measurements were carried out in two ways: 1) Measurements were taken after initializing and referencing the system using the reference points (RPs) once, followed by 30 protrusive and laterotrusive movements (M1 and P1); and 2) Thirty individual measurements were recorded using the RPs before each measurement (M2 and P2). Values for the sagittal condylar path inclination angle (sCPIA) and the Bennett angle (BA) were exported and analyzed. The reproducibility of the system was evaluated using the standard deviations (SDs) of the measurement series (sCPIA and BA for M1, M2, P1, and P2). RESULTS: In vitro tests M1 (SD: sCPIA = 0.08 degrees; BA = 0.06 degrees) and M2 (SD: sCPIA = 0.26 degrees; BA = 0.11 degrees) showed significantly higher reproducibility (P < 0.001) compared with the in vivo measurements P1 (SD: sCPIA = 0.61 degrees; BA = 0.45 degrees) and P2 (SD: sCPIA = 1.4 degrees; BA = 0.65 degrees). CONCLUSION: Within the limitations of the present study, the deviation in vitro, representing the reproducibility of the DMD-System, is smaller than the biologic variance observed in vivo. Therefore, reliable measurements under clinical conditions can be assumed.