Aims and Objectives: The purpose of this study is to compare digital and conventional impression methods by preclinical students in terms of time and ease and to evaluate their preferences and future expectations. Materials and Methods: Twenty volunteered, 2^nd year preclinical students (11 females and 9 males) participated in this study. Students took digital and conventional impressions of the left lower first molar which was made full ceramic crown preparation and opposite full arch from a typodont model (Frasaco, Frasaco GmbH, Tettnang, Germany). They used intraoral scanner (CEREC Omnicam, Sirona Dental GmbH, Bensheim, Germany) for digital impression and also used additional type (Express XT Penta H, 3M ESPE, Seefeld, Germany) and condensation type (Zetaplus, Zhermack SpA, Badia Polesine, Italy) silicones for conventional impression. Their taking impression time was measured. Before taking impression and after taking impression, two kinds of questionnaires were conducted to students about their preference, ease of impression methods, and their future expectations. Statistical analysis was performed by IBM SPSS 23 and Excel 2010 version. Differences between conventional and digital impression in terms of time were analyzed by student’s-t paired test and effect of gender was analyzed by students’s-t independent test. Results: There were statistically significant differences between digital and conventional impression methods in terms of taking impression and total impression time (P < 0.001). But there wasn’t any statistically significant difference between two methods in terms of preparation time. About 85% of students preferred the digital impression method and also 85% of students found that the digital impression method was easy. 95% of students expected to find intraoral scanner in the clinic where working first time. Conclusions: As a result of this study, it has been seen that the students preferred the digital impression method to the conventional impression method and found that the digital impression method was easier.

Objectives: The aim of this study is to evaluate the possible relationship between the presence/absence of the self-reported sleep and/or awake bruxism and the chronotype profiles of dental students. Materials and Methods: The dental students at Istanbul Medipol University and Istanbul Medeniyet University in the fall semester of the 2020-2021 academic year participated in this study. Along with demographic data, an 11-item questionnaire evaluating sleep quality and self-reported sleep and awake bruxism, and a 19-question Morningness-Eveningness Questionnaire (MEQ) determining the chronotypes were applied. The significance level was set at P≤ 0.05 for statistical analysis. Results: 171 students (female:128, 74.9%; male:43, 25.1%) participated in the study. The mean age was 22.32.2. There was no statistical difference between the presence or absence of the bruxism types and the chronotype profiles of the students (P=0.815). The sleep quality in the students with the sleep bruxism was statistically lower than in other types of the bruxism (P<0.05). The participants with the sleep bruxism were statistically more likely to have difficulty concentrating on the daily activities than the participants with other types of the bruxism (P<0.05). Conclusions: There is no relationship between the presence or absence of the bruxism types and the chronotype profiles. However, the sleep bruxism negatively affects both the sleep quality and focusing on the daily activities.

Objective: This study evaluated the polishing properties of the occlusal splint materials obtained using subtractive and additive manufacturing methods with the laboratory-type polishing (LP) and chairside-type polishing (CP) procedures. Material and Methods: Specimens (N=180, n=60 each group) were manufactured using one of the following methods: subtractive manufacturing method (SMM) (M-PM Disc, Merz Dental GmbH), additive manufacturing method (AMM) (Freeprint Splint 2.0, DETAX GmbH & Co. KG), and the conventional manufacturing method (CMM) (Promolux HC, Merz Dental GmbH). Following LP and CP procedures, surface roughness of the specimens was measured using a digital surface profilometer. One representative specimen was selected from each group, and a scanning electron microscope (SEM) image was made. Results: Both the manufacturing method and the polishing procedures significantly affected the results (P<0.01). Interaction terms were also significant (P<0.001). Conclusion: With both polishing methods, surface roughness of the AMM group was the highest and the CMM group the least. Although the CP procedure was more effective than LP with both methods, surface roughness was below the 0.2 micro m threshold after both polishing procedures tested. KEYWORDS CAD-CAM, dental materials, occlusal splints, PMMA, surface properties.

Aim: The aim of this study is to evaluate the quality of the information provided by the most watched videos about bruxism on YouTube™. Material and Method: The results of YouTube™search were examined using the keyword “bruxism”. The searching limited to the first 130 videos. DISCERN and the video information and quality index (VIQI) and the criteria were used for evaluating the videos. Also, the interaction index and the viewing rate of the videos were calculated. The Kruskal-Wallis H Test, Pearson's Chi-Square Test, Spearman's rho correlation were used for statistical analyses. Significance level was taken as p