Digital technology implementation in prosthodontics postgraduate programs in Saudi Arabia: a multi-institutional survey of program directors.

OBJECTIVE: To assess the current status of digital technology (DT) implementation in prosthodontics post-graduate (PG) programs in Saudi Arabian dental institutions. METHODOLOGY: A 19-item survey was created using Google forms and the link was emailed to the 29 prosthodontics PG program directors (advanced clinical training and joint program) in Saudi Arabia. The questionnaire contained five Sect. 1) didactic training and DT usage in PG preclinical, clinical and laboratory training, 2) incorporation of DT in PG program, 3) utilization of DT and the types of cases treated by PG students during their course, 4) information on the faculties involved in prosthodontics PG education, and 5) potential challenges encountered and program directors' satisfaction of the PG program. Descriptive statistics was used to present the frequencies and proportions, and Chi square inferential test was used to compare the participants' response based on the type of PG programs (α = 0.05). RESULTS: Only 28 program directors responded to the survey, yielding a 95.5% response rate. Among the program directors, 24 (85.7%) and 4 (14.3%) directors supervised the advanced clinical training and joint programs, respectively. Among the DT, CAD/CAM was the most used technology (50-80%), followed by intra-oral scanning (28-96%). Digital technology implementation was largely limited by lack of resources or equipment (67%), cost (53%) and scarcity of PG teaching staff (46%). A significant difference was observed between the programs regarding the mandatory use of DT for their cases (p = 0.03). CONCLUSIONS: This multi-institutional survey of program directors revealed that DT is continuously implemented in the last few years. Saudi dental institutions must prioritize implementing and utilizing DT in PG training to graduate competent prosthodontists in this fast-paced digital era. While DT is pivotal in dental education, its implementation is limited in many institutions due to resources or equipment, cost, and lack of trained faculty.

Comparison of surface micro-roughness and adaptation of titanium and cobalt chrome implant abutment fabricated by selective laser melting and conventional techniques.

PURPOSE: The objective of this study was to assess the surface micro-roughness and abutment adaptation of selective laser melting (SLM) implant abutments in comparison to cast and machined implant abutments. METHODS: Forty abutment specimens were divided equally into four groups according to the fabrication technique as follows (n = 10), Machined Ti alloy abutments (Control), Cast CoCr abutments, SLM-CoCr abutments, and SLM-Ti alloy abutments. Forty internal connection implants (Ø 4.0 ×10 mm, Superline™, Dentium Co., Seoul, Korea) were mounted in clear acrylic resin. Fabricated abutments were assessed for surface micro-roughness using a 3D optical noncontact surface microscope. Vertical and horizontal adaptation of the abutment with implant interface was assessed by using Bruker micro-CT. Data was assessed using analysis of variance and Tukey post hoc comparison tests for all the variables except vertical misfit was assessed using Kruskal-Wallis test. Pearson correlation was used to assess dependence between independent variable (surface roughness) and dependent variables (Horizontal misfit and vertical misfit). RESULTS: SLM-Ti abutments showed significantly rougher surface (p < 0.05) among the study groups. While SLM-CoCr abutments were smoother than Cast abutments with mean Ra of 1.30 ± 0.11 and 1.58 ± 0.17 µm, respectively (p < 0.05). For abutment adaptation, SLM-Ti abutments showed the highest horizontal misfit among the groups (p < 0.05). While, SLM-CoCr abutments (29.24 ± 11.11 µm) showed comparable (p > 0.05) horizontal misfit results with Cast (26.08 ± 3.93 µm) and machined (26.45 ± 7.33 µm) abutments. Comparable (p > 0.05) vertical misfit values between Cast CoCr (487.01 ± 40.34 µm), SLM-CoCr (358.38 ± 114.93 µm) and SLM-Ti (299.85 ± 172.88 µm) abutments were observed. A positive correlation was found between the surface roughness of the mating surfaces and abutment adaptation. CONCLUSION: SLM CoCr abutments exhibited low roughness and comparable abutment adaptation (vertically and horizontally) than cast (control) abutments. Therefore, SLM CoCr abutments should be clinically investigated as potential implant abutments for clinical use.

Influence of Acidic Environment on the Hardness, Surface Roughness and Wear Ability of CAD/CAM Resin-Matrix Ceramics.

This study aimed to measure the effect of storage environment on the hardness, surface roughness and wear ability of CAD/CAM resin-matrix ceramics. A total of 200 rectangular-shaped specimens were obtained by sectioning 5 CAD/CAM blocks; Crystal Ultra (CU), Vita Enamic (VE), Lava Ultimate (LU), Cerasmart (CS) and Vita blocks Mark II (MII). Microhardness and surface roughness were measured at baseline and after 7 days of immersion either in saliva or cola (n = 10). The wear ability of the CAD/CAM materials against steatite-ceramics antagonist was determined using a chewing simulator. The data were statistically analyzed using factorial ANOVA followed by post hoc Bonferroni multiple comparison tests (p < 0.05). The independent factors significantly influenced the microhardness and surface roughness (p < 0.05). The highest VHN was observed in MII at baseline (586.97 ± 13.95), while CU showed the lowest VHN after 7 days of immersion in cola (68.3 ± 1.89). On the contrary, the highest Ra was observed after 120,000 chewing cycles for the VE specimens (1.09 ± 0.43 µm) immersed in cola, while LU showed the lowest Ra at baseline (0.07 ± 0.01 µm). The highest % mass loss of the antagonist was observed with MII immersed in cola (1.801%), while CS demonstrated the lowest % mass loss of 0.004% and 0.007% in AS and cola, respectively. This study confirms that the surface properties of tested CAD/CAM materials are susceptible to degradation in an acidic environment except for hardness and wear of CS material.

Effects of background color and thickness on the optical properties of CAD-CAM resin-matrix ceramics.

STATEMENT OF PROBLEM: Information regarding the masking ability of computer-aided design and computer-aided manufacture (CAD-CAM) resin-matrix ceramic materials with different compositions is scarce. PURPOSE: The purpose of this in vitro study was to evaluate the effects of background color and thickness on the optical properties (color and translucency) of CAD-CAM resin-matrix ceramics. MATERIAL AND METHODS: Twelve rectangular specimens were fabricated at a different thickness (1, 1.5, and 2 mm) (n=12) from each of the resin-matrix ceramic materials: Shofu block (SB), Lava Ultimate (LU), CERASMART (CS), VITA ENAMIC (VE), Crystal Ultra (CU), and the VITABLOCS Mark II feldspathic ceramic (VB). The color of the specimens over amalgam, titanium, enamel, and dentin backgrounds was measured with a spectrophotometer, and the color differences (ΔE∗ab) were calculated by using the Commission Internationale de l'Eclairage (CIE) 76 formula. The difference in color of the specimen over the black and white backgrounds was used to calculate the translucency parameter (TP). ANOVA was used to statistically test whether material, background, and thicknesses influenced ΔE∗ab and TP values. Post hoc comparisons were performed to determine the significant difference among the groups (α=.05). RESULTS: The interaction with 2 between factors demonstrated that the material was a factor that significantly influenced ΔE∗ab (P<.001). The highest mean ±standard deviation of ΔE∗ab was recorded in the combination of VB material and 2-mm thickness (1.84 ±0.37), and the lowest with CS material with 1.5-mm thickness (0.47 ±0.24). The type of material and specimen thickness significantly influenced TP (P<.001). The highest and lowest mean ±standard deviation of TP were recorded for the 1-mm-thick CS (14.20 ±0.90) and 2-mm-thick SB (4.91 ±0.42) specimens, respectively. CONCLUSIONS: CERASMART resin-matrix ceramic and VITABLOCS Mark II feldspathic ceramic exhibited high and low masking abilities over the investigated background substrates, respectively. However, irrespective of the thickness, all study materials exhibited acceptable masking abilities.

Influence of Toothbrush Abrasion and Surface Treatments on Roughness and Gloss of Polymer-Infiltrated Ceramics.

The aim of this study was to compare the surface roughness and gloss of polymer-infiltrated ceramics after simulated in vitro toothbrushing in different storage mediums. Four polymer- infiltrated ceramics were evaluated, Lava ultimate (LU), Vita enamic (EN), Shofu (SH), and Crystal ultra (CU). The control group was a feldspathic ceramic, Vita Mark II (VM). One hundred and twenty specimens (12 × 14 × 2.5 mm) were prepared using a precision saw. For each material (n = 24), the specimens were allocated into two groups, polished and stained. The specimens of each group were stored (for 7 days) in either citric acid (0.2N) or distilled water. Data for surface gloss (ΔE*SCE-SCI) and roughness (Ra) were evaluated before (baseline) and after simulated toothbrushing. For toothbrushing simulation, a toothpaste slurry containing a toothpaste of 100 relative dentin abrasion (RDA) and 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Data were analyzed using t-test and ANOVA. A p-value of ≤ to 0.05 was considered significant. The highest mean value of surface gloss was identified in CU (stained-water) (4.3 (0.47)) (ΔE*) and EN (stained-acid) (4.3 (1.00)) (ΔE*) specimens, whereas the lowest mean value was shown by SH (stained-acid) (2.04 (0.42)) (ΔE*) samples. The highest mean value of surface roughness was observed in SH (0.40 (0.99)) Ra (stained-acid) whereas the lowest in VM (0.13 (0.039)) Ra (polished- water). A significant difference (p < 0.05) was observed in surface roughness and gloss between the materials with simulated toothbrushing, except in VM and LU, respectively. Therefore, it can be concluded that simulated toothbrushing impacts on surface roughness and gloss, irrespective of the storage medium.

Influence of toothbrush abrasion and surface treatments on the color and translucency of resin infiltrated hybrid ceramics.

PURPOSE: The study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment. MATERIALS AND METHODS: Four hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test. RESULTS: The maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)]. CONCLUSION: The comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.