Assessment of color stability and translucency of various CAD/CAM ceramics of different compositions and Thicknesses: An in vitro study.

Background: Translucency and optical characteristics significantly affect the aesthetics of ceramic restorations. The introduction of new virgilite crystals to novel ceramic advanced lithium disilicate through a matrix firing process enhances the material's strength and aesthetic quality according to the manufacturer. Materials and Methods: Four types of CAD/CAM ceramics; lithium disilicate (LD), leucite reinforced (LR), advanced lithium disilicate (ALD), and zirconia-reinforced lithium silicate (ZLS) exposed to different staining solutions (tea, cola, coffee, and distilled water). Each ceramic type had 120 specimens, divided into subgroups based on thickness (0.5 mm, 1 mm, and 1.5 mm). Color changes (ΔE00) and translucency parameters (TP00) were measured after thermocycling, and spectrophotometry was employed to evaluate ΔE00 and TP00 after 1, 7, and 30 days of exposure to the staining solutions. Results: ZLS exhibited the lowest color stability, while lithium LD and ALD displayed the highest. Thickness significantly affected color stability, with 0.5 mm thickness showing the least change. The duration of exposure also impacted color changes, with 30 days causing the most significant shift. LD demonstrated the highest translucency. Coffee and tea induced more pronounced reductions in translucency and color stability compared to the control group. Conclusions: Material structure, thickness, staining solution, and exposure duration significantly influenced the color stability and translucency of CAD/CAM ceramics, with LD and ALD demonstrating superior color stability and LD exhibiting the highest translucency.

SEQUEL: Prevalence of dental caries in Saudi Arabia: A systematic review and Meta-analysis.

This meta-analysis investigated the prevalence of dental caries throughout the Kingdom of Saudi Arabia (KSA) between 2011 and 2023 as a follow-up to a previously published review in 2013 by Khan et al. and aimed to provide an update on the current status of caries prevalence in the KSA. A literature search was conducted, and thirty-three articles were included in the final analysis. To determine the prevalence of caries in primary teeth, the 2- to 12-year-old Saudi population was included in the search, and an age range of 6-18 years was used for permanent teeth. The prevalence of caries in the primary and permanent dentition was analyzed separately. As the included studies for the primary and permanent teeth had insignificant heterogeneity, fixed-effect models and forest plots were used to evaluate caries prevalence in both dentitions. In the primary dentition, the mean decayed-missing-filled teeth (dmft) index was 4.14 (95 % confidence interval (CI): 3.11-5.18), with an average prevalence of 75.43 %. For the permanent teeth, the mean DMFT (uppercase used for permanent dentition) was 1.28 (95 % CI: 0.93-1.64), with an average prevalence of 67.7 %. The average dmft/DMFT scores decreased in both primary and permanent teeth compared to the previous meta-analysis by Khan et al., suggesting a beneficial effect of preventative measures on caries prevalence. Continuing these measures is necessary to maintain the downward trend of caries prevalence in the KSA.

Effect of Different Scaling Methods on the Surface Topography of Different CAD/CAM Ceramic Compositions.

This study evaluated the effect of ultrasonic and manual scaling using different scaler materials on the surface topography of computer-aided designing and computer-aided manufacturing (CAD/CAM) ceramic compositions. After scaling with manual and ultrasonic scalers, the surface properties of four classes of CAD/CAM ceramic discs: lithium disilicate (IPE), leucite-reinforced (IPS), advanced lithium disilicate (CT), and zirconia-reinforced lithium silicate (CD) of 1.5 mm thickness were evaluated. Surface roughness was measured before and after treatment, and scanning electron microscopy was used to evaluate the surface topography following the performed scaling procedures. Two-way ANOVA was conducted to assess the association of the ceramic material and scaling method with the surface roughness. There was a significant difference in the surface roughness between the ceramic materials subjected to different scaling methods (p < 0.001). Post-hoc analyses revealed significant differences between all groups except for IPE and IPS where no significant differences were detected between them. CD showed the highest surface roughness values, while CT showed the lowest surface roughness values for the control specimens and after exposure to different scaling methods. Moreover, the specimens subjected to ultrasonic scaling displayed the highest roughness values, while the least surface roughness was noted with the plastic scaling method.

Influences of Different CAD/CAM Ceramic Compositions and Thicknesses on the Mechanical Properties of Ceramic Restorations: An In Vitro Study.

The aim of this study was to assess the influences of different CAD/CAM ceramic compositions and thicknesses on the surface roughness and hardness of ceramic restorations. Four different ceramics were used in the current study: lithium disilicate (LD), leucite reinforced (LE), advanced lithium disilicate (ALD), and zirconia-reinforced lithium silicate (ZLS). Each group included 30 specimens subdivided into three different ceramic thicknesses (0.5, 1 and 1.5 mm thicknesses). The microhardness was measured for all the specimens using a microhardness testing machine, while the surface roughness was measured using a non-contact optical profilometer at three intervals (before toothbrushing and after toothbrushing, with and without toothpaste). Three-way and two-way ANOVA were used to determine the factors influencing the surface roughness and microhardness. There was a significant difference in the surface roughness between the studied groups for all the thicknesses. The findings showed that ALD had the lowest surface roughness, while ZLS showed the highest surface roughness. Moreover, ALD, followed by ZLS, had the highest hardness, while LD and LE had the lowest hardness values. Regarding the thicknesses, both the 0.5 and 1 mm ceramic thicknesses showed a significantly lower surface roughness than the 1.5 mm thickness, while the 1.5 mm thickness showed a significantly higher microhardness than the 0.5 mm thickness. The surface roughness and hardness were significantly affected by the ceramic composition and type of filler. It is recommended to use 1.5 mm-thick ceramic materials for the fabrication of definitive full-coverage ceramic restorations, while veneers require 0.5 mm-thick materials. ALD is a promising CAD/CAM material that can be used for the fabrication of restorations with a proper strength in both anterior and posterior regions.