Effect of Water Flossing and Manual Flossing on Color Stability and Surface Roughness of Zirconia and Lithium Disilicate: An In Vitro Study

Abstract

Introduction: Maintenance of surface integrity and color stability is essential for the long-term esthetics of ceramic restorations. Water flossers, as an emerging adjunct to conventional oral hygiene, may influence the surface characteristics of dental materials.

Objectives:To evaluate the effects of water flossing and manual flossing on the surface roughness and color stability of zirconia and lithium disilicate.

Methods: 30 CAD/CAM milled samples (15 zirconia, 15 lithium disilicate) were assigned into three subgroups per material: water flosser, manual floss, and control (n=5 each). Profilometer and digital spectrophotometer were used to record surface roughness and color (ΔE) before and after intervention. Water flosser was standardized to 90 psi pressure in pulse mode. ANOVA test was used for statistical analysis (p < 0.05).

Results:Water flossing significantly increased surface roughness in both materials, especially lithium disilicate (ΔRa = 1.162 µm). Color change (ΔE) was statistically significant in lithium disilicate after water flossing (ΔE = 4, p=0.04). Manual flossing had minimal impact on zirconia and Lithium disicilate

Conclusions:  Water flossing, while effective in plaque control, may compromise ceramic surface integrity. Lithium disilicate showed greater susceptibility to surface degradation than zirconia. Clinical discretion is advised when recommending water flossers for patients with esthetic ceramic restorations.