Effect of staining and whitening systems on color stability of computer aided design/computer aided manufacturing lithium disilicate glass ceramic.

Purpose: To investigate the effect of coffee stain and whitening systems on the color stability of CAD/CAM glazed lithium disilicate glass-ceramics (LDGCs). Methods:  68 glazed LDGC discs (12 × 10 × 2 mm) were fabricated using blocks of CAD/CAM systems (IPS e.max CAD ceramic). Baseline color was measured (CIE/L*a*b*), and specimens were randomized into four groups (n = 17). All specimens were stained (coffee solution; 24 h/d × 12) and then subjected to two whitening protocols. G1- (kept moist × 7 days); G2-positive control (brushed with distilled water, 200gm/load, 2 min twice daily × 7 days); G3- whitening toothpaste (Colgate optic white; relative dentin abrasivity = 100, 200gm/load, 2 min twice daily × 7 days) and G4-simulated at-home bleaching protocol (Opalescence,15% carbamide peroxide (CP), 6 h/day × 7 days). The study outcome was color change (ΔE) measured at baseline, after staining, and after whitening treatments. Data were analyzed using paired T-test and one-way ANOVA (α = 0.05). Results: All groups stained equally (p > 0.05) but were not clinically significant (ΔE ≤ 1.05). Stains were significantly (p ≤ 0.01) improved in G2 and G3 (ΔE = 0.69 and 0.63), yet were not eliminated compared to bleaching, which had the highest color improvement and completely removed the stains (ΔE = 0.72). Conclusions: Glazed LDGC was color stable after simulating one year of coffee staining. Bleaching, using 15% CP for a week, completely removed the stains and returned the LDGCs to their original shade. However, simulating eight months of brushing, regardless of the toothpaste content, improved the color outcome but didn't remove it completely.

The Effectiveness of Students' Performance in Preclinical Fixed Prosthodontics Course in Predicting Subsequent Clinical Performance.

PURPOSE: To evaluate the correlation between students' achieved grades in a preclinical fixed prosthodontics course and their performance in the same discipline's clinical courses. MATERIALS AND METHODS: This study was conducted in 2019 on 76 students who passed all preclinical and clinical fixed prosthodontics courses. Their final examination grades in preclinical and clinical prosthodontics courses were compiled and made anonymous. The Statistical Package for the Social Sciences (SPSS Version 23) was used to analyze the data. Descriptive statistics and correlation coefficient were used to assess the relation between preclinical and clinical grades. RESULTS: A statistically significant positive correlation existed between the students' preclinical and combined clinical final examination grades (r = 0.45, p < 0.001). In relation to sex, females showed a significantly higher correlation (r = 0.56, p = 0.001) compared to males (r = 0.25, p = 0.1). In addition, students' clinical grade prediction from their preclinical performance was 20.5%. CONCLUSION: These findings emphasize the importance of preclinical courses and suggest that maximizing preclinical years' efforts can reflect positively on students' competence in their future clinical practice.

The Status of Digital Dental Technology Implementation in the Saudi Dental Schools' Curriculum: A National Cross-Sectional Survey for Healthcare Digitization.

Objective: The primary objective of this cross-sectional national study was to investigate the status of digital dental technology (DDT) adoption in Saudi Arabian undergraduate dental education. A secondary objective was to explore the impact of dental schools' funding sources to incorporate digital technologies. Methods: A self-administered questionnaire was distributed to the chairpersons of prosthetic sciences departments of the 27 dental schools in Saudi Arabia. If any department chairman failed to respond to the survey, a designated full-time faculty member was contacted to fill out the form. The participants were asked about the school's sector, DDT implementation in the curriculum, implemented level, their perceptions of the facilitators and challenges for incorporating DDT. Results: Of the 27 dental schools (18 public and 8 private), 26 responded to the questionnaire (response rate: 96.3%). The geographic distribution of the respondent schools was as follows: 12 schools in the central region, 6 in the western region, and 8 in other regions. Seventeen schools secure and preserve patients' records using electronic software, whereas nine schools use paper charts. Seventeen schools (64,4%) implemented DDT in their curricula. The schools that did not incorporate DDT into their undergraduate curricula were due to not being included in the curriculum (78%), lack of expertise (66%), untrained faculty and staff (44%), and cost (33%). Conclusions: This national study showed that digital components still need to be integrated into Saudi Arabian dental schools' curricula and patient care treatment. Additionally, there was no association between funding sources and the DDT implementation into the current curricula. Consequently, Saudi dental schools must emphasize the implementation and utilization of DDT to align with Saudi Vision 2030 for healthcare digitization and to graduate competent dentists in digital dental care.

The Effects of a coffee beverage and whitening systems on surface roughness and gloss of CAD/CAM lithium disilicate glass ceramics.

OBJECTIVES: To investigate the effects of a coffee beverage and two whitening systems on the surface roughness and gloss of glazed Lithium Disilicate Glass-Ceramics (LDGC) for computer-aided design/computer-aided manufacturing (CAD/CAM) systems. METHODS: Sixty-eight LDGC disks (12 × 10 × 2 mm) were prepared from blocks of CAD/CAM systems (IPS e.max CAD ceramic). Baseline measurements for surface roughness (Ra) and gloss (GU) were taken using a 3-D optical profilometer and a glossmeter, respectively; then specimens were randomized into four groups (n = 17). All specimens were immersed in a coffee solution (24 h × 12 days) then subjected to two whitening systems. G1-negative control (kept moist × 7 days); G2-positive control (brushed with distilled water, 200 g/load, 2 min twice daily × 7 days); G3-whitening toothpaste (Colgate optic white; relative dentin abrasivity (RDA) = 100, 200 g/load, 2 min twice daily × 7 days); and G4-simulated at-home bleaching protocol (Opalescence,15% carbamide peroxide (CP), 6 h/day × 7 days). The study outcomes were measured at baseline and after the treatments. Data were analyzed using paired T-test and one-way ANOVA (α = 0.05). RESULTS: The mean surface roughness significantly increased (p ⩽ 0.002) for all groups after the designated treatment protocols. Among groups, the mean surface roughness of G2 and G3 were significantly higher (p ⩽ 0.001) (Ra: 0.51 and 0.57 µm, respectively) compared to the control group (Ra: 0.23 µm), and were not significantly different from G4 (Ra: 0.46 µm). Surface gloss decreased with no significant change within or among groups after treatment. CONCLUSION: All glazed LDGC had a significant increase in surface roughness after being subjected to simulated 1 year of coffee drinking and whitening systems (15% CP and whitening toothpaste), and the greatest change was associated with brushing (simulating 8 months). However, coffee beverages and whitening systems had no significant effect on the surface gloss.

Survey of perceived stress-inducing problems among dental students, Saudi Arabia.

OBJECTIVE: This study was conducted to assess the problems related to stress encountered by Saudi dental students. METHODS: One thousand and thirty questionnaires were distributed in four dental schools to all students from 2nd year level up to the internship level. The questionnaire contained 66 items organized into four categories: personal and administrative, theoretical, preclinical and clinical. The relationship between the demographic variables and students' academic performance with the investigated items was also assessed. RESULTS: The response rate was 53%. Saudi dental students showed high levels of perceived stress. The clinical training issues imposed the highest level of stress on the students. Some significant relationships between the investigated variables and the level of the perceived stress were found. CONCLUSIONS: Female students had higher mean overall problem scores compared to male students, and second-year students showed lower perceived problems compared to other students.