The Effect of Plaque Detectors on the Color Stability of Two Types of Restorative Materials

Objective: To investigate the color stability of a one-shade resin-based composite material (RC) and a glass-ionomer cement (GIC) after staining with plaque detectors (PDs) with different formulations and delivery forms. Materials and Methods: Rectangular-shaped specimens (7 × 3 × 2 mm) were produced with RC (Venus Diamond One, Kulzer) and GIC (Fujy IX GP, GC) (n = 30). Further, the following PDs were used on the specimens: (1) tablets (T; Plaq-Search, TePe); (2) mouthwash (M; Plaque Agent, Miradent); and (3) light-curing liquid (L; Plaque test, Ivoclar). The PDs were removed with dedicated toothbrushes (T1) and the specimens were repolished (T2). The protocol was repeated after 1 week of storage in artificial saliva (staining—T3 and repolishing—T4). Color measurement were performed at baseline (T0) and all testing times (T1—T4) using a recently introduced digital colorimeter (SmartColor, Smart Vision). Color changes (ΔEab) compared to T0 were automatically recorded by the digital instrument. The data were statistically analyzed (p < 0.05). Results: The type of PD, the polishing procedure and their interactions influenced the color stability of both restorative materials (p < 0.05). Particularly, after the second PDs application, M and L produced the highest color changes (p < 0.05), with GIC showing higher color variability than RC. Although repolishing reduced the color changes of RC (p < 0.05), it could not reestablish the initial color of GIC, irrespective of the PD used (p < 0.05). Except for RC associated with T, all materials exhibited discoloration above the clinical perceptibility (1.77) and acceptability (2.66) thresholds. Conclusions: The influence of PDs on the color stability of RC and GIC was material-dependent. GIC showed higher color instability than RC. Repolishing could not reestablish the original color of GIC and only attenuated the color changes of the one-shade RC. The newly introduced digital colorimeter was an important tool to standardize and simplify color measurement evaluations. Clinical Significance: PDs can pose a potential risk to the color stability of restorative materials. Dental practitioners should be careful when recommending the frequency of at-home application of PDs, taking into consideration the material properties and the position of the restorations of each patient.