Objectives: the aims of this study were the development of a novel questionnaire to assess the impact of prosthetic treatments on oral health-related quality of life (OHRQoL) and the performance of a prospective pilot study. Background: the currently preferred OHRQoL measurement tool is the oral health impact profile-49 (OHIP-49), a self-report questionnaire which mainly focuses on general effects related to oral health. Materials and methods: A total of 24 adult participants (9 females and 15 males) were recruited and asked to complete the novel questionnaire twice: once before the prosthetic treatment began and 4–6 weeks post-treatment. The assessment of the change in OHRQoL was based on the differences in participants’ answers before and after treatment. Data were analyzed using ANOVA with a repeated-measures method and t-tests. The reliability of the questionnaire was tested using Cronbach’s alpha and intraclass coefficient (ICC). Results: The questionnaire was found to be reliable (α ≥ 0.6), with “social disability” having the highest score (α = 0.868). All domains showed an improvement (α < 0.005) in OHRQoL scores after treatment. Conclusions: the novel questionnaire tested in this study was found to be reliable and convenient to use, and demonstrated that prosthetic treatments have a significant positive effect on OHRQoL post-treatment scores.

Background: The purpose of this in vitro study was to compare the inter-implant distance, inter-implant axis, and intra-implant axis of three implants in a straight line by using a laboratory scanner (LBS) versus an intra-oral scanner (IOS) with two different intra-oral scan bodies (ISBs). Methods: A 3D model was printed with internal hex implant analogs of three implants in positions 15#, 16#, and 17#. Two standard intra-oral scan bodies (ISBs) were used: MIS ISB (two-piece titanium) and Zirkonzhan ISB (two-piece titanium). Both ISBs were scanned using 7 Series dental wings (LBS) and 30 times using Primescan (IOS). For each scan, a stereolithography (STL) file was created and a comparison between all the scans was performed through superimposition of the STL files by using 3D analysis software (PolyWorks^® 2020; InnovMetric, Québec, QC, Canada). A Kolmogorov–Smirnov test was performed followed by a Mann–Whitney test (p < 0.05). Results: The change in inter-implant distance for the MIS ISB was significantly lower compared to the ZZ (p < 0.05). The change in intra-implant angle was significantly lower for the ZZ ISB compared to MIS (p < 0.05). The changes in inter-implant angle between the mesial and middle and between the middle and distal were significantly lower for MIS compared to ZZ in contrast to mesial to distal, which was significantly higher (p < 0.05). Conclusions: Both ISBs showed differences in all the parameters between the LBS and the IOS. The geometry of the scan abutment had an impact on the inter-implant distance as the changes in the inter-implant distance were significantly lower for the MIS ISB. The changes in the intra-implant angle were significantly lower for the ZZ ISB. There is a need for further research examining the influence of geometry, material, and scan abutment parts on the trueness.

Background: This study compared the influence of three different radial spacers (60,90,120 microns) on the marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total of 45 abutment acrylic teeth were divided into three groups of different radial spacers (60, 90, and 120 microns). In each group 15 teeth were scanned by Omnicam intra oral scanner and ZLS crowns were ground. For each unit the marginal gap was evaluated at four regions of interest by scanning electronic microscope (SEM). To compare the marginal gap between the three groups a one-way ANOVA with post-hoc Bonferroni test was preformed (α = 0.05). Results: The marginal gap for a 60 microns (162.99 ± 16.25 µm) radial spacer was found significantly higher than 90 (41.85 ± 3.57 µm) and 120 (41.85 ± 5.3 µm) microns radial spacers (p < 0.05). Between 90- and 120-micron radial spacers no difference was obtained. (p < 0.05). Conclusions: A radial spacer of 60 microns showed a significantly higher marginal gap compared to 90 and 120 microns and was not clinically accepted (>120 microns). For both 90 and 120 microns the marginal gap was clinically accepted (<120 microns) with no difference between the groups. The radial spacer which should be optimum for CELTRA^® DUO crowns is 90 microns.

Background. The aim of this study was to evaluate the changing levels of stress among dental students during 8 months of a basic manual skills course in the preclinical year and to examine the association between stress and dental performance. Methods. A longitudinal study was conducted in the 2023 academic year in a total of 58 (male = 17 and female = 41; mean age = 26.43, range 22–33) undergraduate dental students at Tel Aviv University of dentistry during their fourth year of study. Depression Anxiety Stress Scale (DASS‐21) and Dental Environment Stress (DES) questionnaires were used to assess the psychological well‐being and the severity of DASS symptoms experienced by the students. The students’ dental performances were assessed using two manual tests on plastic teeth. The questionnaires and the manual tests were used at three periods of time, T0, T1, and T2. Wilcoxon signed‐rank tests were performed to compare the DASS scores and DES stressors of dental students between T0, T1, and T2. Kendall’s nonparametric correlations were calculated to investigate the relationships of DES stressors and depression, anxiety, and stress scores with manual performance. Conclusions. The perception of high stress by dental students is due to the stressful education process of the preclinical year. There is an inverse correlation between the lower level of anxiety and the increase level of dental performance with 74% of the variance in dental performance explained by the anxiety score. Work‐related stressors such as manual skills might reduce dental performance in contrast to non‐work‐related factors such as financial obligations, personal issues, and family factors, which might increase student dental performance.

Background: This study compared the marginal gap (MG) and absolute marginal discrepancy (AMD) of computer-aided design and computer-aided manufacturing (CAD–CAM) used in open systems (OSs) and closed systems (CSs) for producing monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns. Methods: 60 ZLS ceramic crowns were cemented to abutment acrylic teeth; thirty crowns were designed and milled by an OS, and thirty by a CS. All crowns were sectioned for evaluating the marginal gap by scanning electronic microscopy (SEM). To compare the marginal gap between CS and OS techniques, data were analyzed using the independent-samples Mann–Whitney U Test (α = 0.05). Results: AMD was found to be significantly better for the closed system (p < 0.05). Mean AMD values for the CS were 148 µm, and for the OS it was 196 µm. MG was found to be significantly better for the OS (p < 0.05). Mean MG values for the CS were 55 µm, and for the OS they were 38 µm. Conclusions: The marginal gap in relation to AMD was significantly better for CS. However, the marginal gap in relation to MG was significantly better for OS. Both techniques showed clinically acceptable MG values (<120 µm).

Accurate assessment of dental student performance during preclinical operative mannequin courses is an essential milestone within the educational process. Training on novel, multicolored 3D-printed teeth resulted in higher performances of the students in comparison to training on standard, monochromatic plastic teeth. However, low reliability of students’ grading using standard, monochromatic plastic teeth was reported. The aim of this study was to verify whether the use of 3D multicolored teeth can (1) provide better inter- and intra-examiner reliability, and (2) assess the effect of instructors’ experience on their reliability. The novel tooth analogs consisted of digitally planned and 3D-printed plastic teeth containing green, yellow, and red stratifications according to increasing depths of preparation. Thirty-seven dental students performed three Class I preparations on the 3D-printed teeth, and these underwent blind evaluation by two examiners of varied experience at two timepoints. The data were compared with preparations done on conventional (monochromatic) plastic teeth. Results indicated excellent inter-examiner reliability on 3D-printed teeth (0.768 < ICC < 0.929), but only moderate reliability with conventional plastic teeth (0.314 < ICC < 0.672). The examiner having more experience was found to show higher intra-examiner reliability (ICC = 0.716 and 0.612 using 3D-printed teeth and conventional teeth, respectively) than the less experienced examiner (ICC = 0.481 and 0.095 using 3D-printed teeth and conventional teeth, respectively). The novel, multicolored 3D-printed teeth can provide more objective evaluation of cavity preparation compared with conventional plastic teeth.