Surface Topography, Gloss and Flexural Strength of Pressable Ceramic After Finishing-Polishing Protocols

Abstract

This study evaluated the effect of different finishing-polishing protocols on surface roughness, gloss, morphology and biaxial flexural strength of pressable fluorapatite glass ceramic. Thirty ceramic discs (12x1 mm) were produced and divided into five groups (n=6): CT: control (glaze); DA: fine grit diamond bur; DG: DA + new glaze layer; DP: DA + felt disk with fine grit diamond paste; DK: DA+ sequential polishing with silicon abrasive instruments, goat hair brush and cotton wheel. The specimens were analyzed for surface roughness (Ra) under profilometry and atomic force microscopy (AFM). Gloss was measured with spectrophotometry and micromorphology with scanning electron microscopy (SEM). Flexural strength was assessed by biaxial flexural strength test. Data were analyzed using one-way ANOVA and Tukey’s post hoc test (a=0.05). DK showed the lowest surface roughness values and DA presented the highest in the perfilometer analysis. No significant differences were observed in the AFM for the CT, DG and DK groups, which presented the lower surface roughness; DA and DP had the higher Ra values. The DA, DP and CT showed the lowest surface gloss values, and the reflectance was significantly different from those observed for DK and DG groups. SEM analysis revealed the smoothest surface for DK group, followed by DG and CT groups; DA and DP groups exhibited variable degrees of surface irregularities. No significant differences were observed among groups for the biaxial flexural strength. The polishing protocol used in DK group can be a good alternative for chairside finishing of adjusted pressable fluorapatite glass ceramic surfaces.

Assessment of Color Stainability of Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) Ceramic Materials After Hot and Cold Coffee Immersion at Different Time Intervals

“…The value of ΔE 00 is clinically important and challenging at different levels of color measurements. It has been shown that the borderline ΔE 00 which is perceptible to all people in a color test is 2.5 [ 14 , 28 ]. So, identifying the value of ΔE 00 that is perceptible or clinically acceptable is challenging, and different levels have been suggested [ 21 , 28 – 30 ].…”

“…It has been shown that the borderline ΔE 00 which is perceptible to all people in a color test is 2.5 [ 14 , 28 ]. So, identifying the value of ΔE 00 that is perceptible or clinically acceptable is challenging, and different levels have been suggested [ 21 , 28 – 30 ]. Based on the previous studies, the ΔE 00 values from 1 to 3.3 units considered as clinically acceptable, while ΔE 00 values greater than 3.3 are considered to be clinically unacceptable [ 22 , 31 – 38 ].…”

The effect of coffee and whitening systems on surface roughness and gloss of CAD/CAM lithium disilicate glass cermaics

“…2 The restoration's surface texture (surface roughness, gloss, and luster) significantly impacts the esthetic outcome and longevity of the dental prostheses, especially in challenging clinical cases of a single crown in an esthetic zone. 3 LDGC has proven to be biocompatible with excellent physical and mechanical properties such as; high esthetics, color stability, surface gloss, luster, low thermal conductivity, and wear resistance. 4 The application of a glaze layer during the final step of the ceramic fabrication minimizes several physical external factors affecting the restoration's surface smoothness, gloss, and luster.…”

Comparison of the Degree of Staining of Computer-Aided Design-Computer-Aided Manufacture (CAD-CAM) Ceramic Veneers by Green Tea, Coffee, and Coca-Cola Using a Digital Spectrophotometer

“…The surface texture of the restoration as surface roughness (Ra) and surface depth (Rz) has a substantial impact on aesthetics and durability of this ceramic material [ 8 , 9 ]. A rough surface has a negative impact on color and light reflection.…”