RESUMEN
STATEMENT OF PROBLEM: Surface treatments may affect the optical properties of ceramic veneers before cementation. PURPOSE: The purpose of this study was to evaluate whether various surface treatments affect the optical properties of different types of ceramic veneers. MATERIAL AND METHODS: Disk-shaped ceramic veneers (N=280) were prepared from the IPS e.max Press, e.max CAD, Empress Esthetic, e.max Ceram, and Inline ceramic systems with 0.5-mm and 1.0-mm thicknesses. The ceramics were divided into 4 groups: no surface treatments; etched with hydrofluoric acid; airborne-particle abraded with 30-µm Al2O3; and irradiated with erbium:yttrium-aluminum-garnet laser. A translucent shade of resin was chosen for cementation. Color parameters were examined with a colorimeter. Statistical analyses were done with 3-way ANOVA and the Bonferroni test (P=.05). RESULTS: Significant interactions were noted between the surface treatments, ceramic type, and thickness for ΔE values (P=.01), and no significant interactions were noted for L* (P=.773), a* (P=.984), and b* (P=.998). The greatest color change occurred after airborne-particle abrasion with 0.5-mm-thick e.max Press (2.9 ΔE). Significant differences in ΔE values were found among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 0.5-mm-thick ceramics, except IPS Inline, and among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 1.0-mm-thick ceramics, except Empress Esthetic ceramics. CONCLUSIONS: The color change of the ceramics increased after the surface treatments, particularly as the ceramics became thinner.
Asunto(s)
Porcelana Dental/química , Coronas con Frente Estético , Grabado Ácido Dental/métodos , Óxido de Aluminio/química , Silicatos de Aluminio/química , Silicatos de Aluminio/efectos de la radiación , Apatitas/química , Apatitas/efectos de la radiación , Color , Colorimetría/métodos , Grabado Dental/métodos , Porcelana Dental/efectos de la radiación , Humanos , Ácido Fluorhídrico/química , Láseres de Estado Sólido , Ensayo de Materiales , Cementos de Resina/química , Silanos/química , Propiedades de SuperficieRESUMEN
Laser-induced prevention of dental caries has been studied extensively. However, the cariostatic mechanisms of a combined fluoride-laser treatment are not well-understood. Using micro- computed tomography (micro-CT), we quantified the effect of fluoride and/or Er:YAG laser treatment on enamel demineralization. The mean mineral loss (%/V) for each group was 4,870 ± 1,434 (fluoride followed by laser treatment), 6,341 ± 2,204 (laser treatment), 7,669 ± 2,255 (fluoride treatment), and 10,779 ± 2,936 (control). The preventive effect of the laser (p < 0.001) and fluoride (p = 0.010) treatment was statistically significant. Characterized by micro-x-ray diffraction (XRD) analysis, the significant contraction in the a-axis after both laser and combined laser/fluoride treatment was revealed (both p < 0.05). In conclusion, subablative low-energy Er:YAG laser irradiation following fluoride treatment may instantaneously transform enamel hydroxyapatite into fluoridated hydroxyapatite to reduce enamel solubility as a preventive treatment for enamel demineralization.