Surface Roughness and Color stability of Provisional Restorative Materials Fabricated Using Different Methods After Immersion in Various Storage Media

Abstract

Objectives: To investigate and compare the color stability and surface roughness of provisional restorative materials fabricated by 3D printing, milling and conventional techniques after immersion in different storage media. Materials and methods:The 84-disc specimens were fabricated and divided into 3 groups according to the technique of fabrication (n=28), group C: Conventional techniques, group M: milled technique, group P: 3d printed technique. Each group was divided into 4 subgroups according to storage media (n=7), Subgroup D: distilled water, subgroup C: coffee solution, subgroup Co: cola, and subgroup O: orange juice. Baseline color was measured using spectrophotometer then measured after 2 and 4 weeks of immersion in different storage media. Color change (ΔE) was assessed using of the CIE L*a*b* system. Surface roughness was also measured using profilometer for all specimens before and after immersion in staining solutions. The data was then collected and statistically analyzed using two-way ANOVA. The significance level was set at p<0.05 within all tests.Results: Two-way ANOVA showed that the fabrication technique and interaction between variables had a significant effect on surface roughness. There was a significant interaction between fabrication method, solution type and storage time on color stability. Conclusions:The surface roughness of 3D printed materials was higher than milled and conventional groups. 3D printed and CAD-CAM milled materials had better color stability compared to conventional group.

<i>In-vitro</i> evaluation of wear characteristics, microhardness and color stability of dental restorative CAD/CAM materials

“…The other 120 specimens for color analysis and microhardness tests were aged using 1,500 thermocycles (THE-1100, SD Mechatronic), between 5°C-55°C and dwell time of 15 s. Ten specimens from each group were immersed in coffee solution and kept at 25°C room temperature for 7 days. The solution was generated by adding 30 gr of coffee (Nescafe Gold, Nestle, Vevey, Switzerland) into 100 mL of distilled water (pH of coffee is 5.00) 10) . Ten specimens from each group were assigned as the control group, which were also kept in distilled water for 7 days at 25°C room temperature.…”

“…Although the pH of coffee is 5.00 10) , as it dissolves in water, the impact of this water intake may damage the polymer matrix. Following the absorption of water from polymer ingredients, the coupling agents may hydrolyze and adversely affect the chemical bond between resin matrix and the filler particles.…”