Aging Restorations in the Esthetic Zone: A Visual and Spectrophotometric Outcome

Area of Science:

• Dental Materials Science
• Esthetic Dentistry
• Biomaterials

Background:

• Direct and indirect restorative materials are used for esthetic zone tooth restoration.
• Color changes over time can lead to patient dissatisfaction and replacement needs.
• Lack of clinical monitoring necessitates methods to assess color stability.

Purpose of the Study:

• To assess the color stability of direct and indirect restorative materials.
• To evaluate materials after simultaneous aging in coffee and simulated toothbrushing.
• To determine the effect of repolishing on color stability.

Main Methods:

• Seven restorative materials were tested: packable composite resin (PC), flowable composite resin (FC), lithium disilicate (LD), 4% yttria partially stabilized zirconia (4Y-PSZ), zirconia reinforced lithium silicate (LS), additive manufactured nanoceramic (AM), and milled composite resin (MC).
• Materials underwent 28 days of aging involving coffee immersion and toothbrush simulation.
• Color stability was assessed using spectrophotometry and photography, with color difference (ΔE_oo) calculated before and after repolishing.

Main Results:

• Both material type and aging significantly affected color change (p < 0.001).
• Additive manufactured nanoceramic (AM) showed the greatest color difference (9.1 ± 0.87) after aging.
• Repolishing reduced ΔE_oo for all materials, with 4Y-PSZ exhibiting the lowest values (0.70 ± 0.53).

Conclusions:

• Lithium disilicate (LD) veneers demonstrated superior color stability during aging.
• Repolishing can restore esthetic materials to an acceptable color.
• Additive manufactured nanoceramic (AM) lacked color stability and showed margin staining, highlighting the importance of material selection for esthetic longevity.