Influence of polishing systems on roughness and color change of two dental ceramics

Abstract

PURPOSE To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution. MATERIALS AND METHODS 88 ceramic discs (1.0 mm × 10.0 mm) were manufactured - 44 nano-fluorapatite layering ceramics (IPS e.max Ceram. Group C) and 44 pressed lithium disilicate ceramic discs (IPS e. max Press - Group P). Each group was divided into 4 subgroups according to surface treatments: (G) Glaze, (S) Shofu polishing system (Shofu Inc.), (E) Edenta AG polishing System, (KG) 30-µm diamond granulation tip. Surface roughness (Ra) and color change (ΔE) measurings after the surface treatments were performed, before and 12 days after the immersion in coffee solution. A samples' qualitative analysis was conducted with a scanning electron microscopy (SEM). Data were statistically-treated with one-way-ANOVA and Duncan's tests, apart from paired t-test and Pearson's correlation test (α=5%). RESULTS The decrescent order, both for surface roughness (Ra) and ΔE for both ceramics were: KG > E > S > G ( P <.05). With exception for PG and CG subgroups, which did not present statistical difference between them, all other pressed ceramics subgroups presented smaller Ra values and greater ΔE values than the layering ceramics subgroups ( P <.05). CONCLUSION Although mechanical polishing systems presented intermediate Ra values, their colors were considered clinically acceptable. There is a strong correlation between the surface roughness and the color change of tested ceramics.

Effects of Khat on Surface Roughness and Color of Feldspathic and Zirconia Porcelain Materials under Simulated Oral Cavity Conditions

“…In this study, the value of the ∆E* (2.12) was slightly high (Table 3), and this can be explained by the high degree of fluorosis among the population in Jazan city. Alabdulaaly et al concluded that the fluoride levels in Jazan exceeded the maximum allowed limits [59] Algazali et al performed a clinical in vivo study and found that ∆E* of 2.8 is clinically acceptable [28] [60,61]. This result was close to the value obtained in this study for natural teeth (3.45) (Table 3).…”

Effect of different surface treatments on optical, colorimetric, and surface characteristics of a lithium disilicate glass–ceramic

“…It is already known that an increase in roughness and topographical alterations may inherently affect the light transmittance through a restorative material. 21,24,25 The influencing mechanism is explained by the fact that the light direction and incidence is altered when light transmits through a roughened surface, and the material consequently shows opacity, among other optical and colorimetric characteristics (light transmittance and color differences -ΔE 00 ) which may also be altered. It could be accepted that this is the main F I G U R E 3 SEM analysis in a topographic and lateral view of the ceramic surface after surface treatments have been performed…”

“…[17][18][19] These adjustments inherently influence the surface characteristics (topography and roughness features) of ceramics, and in doing so they may potentially change the optical and mechanical properties of these materials. [20][21][22] From this viewpoint, the literature has shown that these procedures may introduce different types of damage/defects into the material's surface, creating different roughness, and surface topography patterns. 18,22,23 It is well-known that an increase in roughness inherently affects the light transmittance through a restorative material.…”

“…18,22,23 It is well-known that an increase in roughness inherently affects the light transmittance through a restorative material. 21,24,25 Thus, when light is transmitted through a roughened surface, the direction and incidence of light is altered, consequently increasing the material's opacity, and further altering other optical characteristics. 24,25 Therefore, the restorative surface should be subjected to subsequent processing treatments after clinical adjustments with diamond burs for smoothening and restoring the optical properties.…”

“…24,25 Therefore, the restorative surface should be subjected to subsequent processing treatments after clinical adjustments with diamond burs for smoothening and restoring the optical properties. 21 However, scarce information exists on this theme to guide the clinicians' choice.…”