Color Stability and Cleanability of Orthodontic Enamel Sealants

Objectives: Enamel decalcification is one of the most common adverse effects of orthodontic treatment. Fluoride releasing enamel sealants were developed to reduce such decalcification. The color stability of enamel sealants is an important factor to ensure their acceptability by dentist and patient.

Objectives were to asses the color stability of four orthodontic sealants after exposure to artificial ageing and to different staining solutions. Furthermore, their cleanability after polishing should be evaluated.
Methods: Selected were composite-based, silicon-based, composite-modified and glas-ionomer based sealants (Pro Seal®, Light Bond™, Sealant Protecto®, Clinpro™ XT Varnish). Natural teeth served as medium. Immersion solutions were water (control), black tee, curcuma and black currant juice.
In a standardized experimental set-up all samples were measured eight times with a spectroradiometer (Photoresearch PR670) at baseline, after thermocycling, after 7 days, 3,4,5 weeks of immersion, and finally after polishing (5” and 15”).The data of spectroradiometer were expressed using the Commission Internationale d'Eclairage (CIE) L*a*b* color notation system. Color difference between the sealed and the non-sealed (control) half of each natural tooth was calculated respective to time and cleaning. Data were analyzed by three-way ANOVA and significance level was set at p≤0.01.

Results: Thermocycling had a significant effect on color stability (p≤0.05).However, sealed and non-sealed surfaces did not differ significantly. After exposure to staining solutions all sealed surfaces showed significant color changes depending on immersion solution and manufacturer (p≤0.01); Color change predominately occurred for all sealants in the first week of staining (p≤0.01). Surface cleaning by polishing significantly reduced the color change.
Conclusions: Immersion solutions, time of immersion and thermocycling have an impact on color stability of orthodontic sealants. The effectiveness of polishing was demonstrated. Sealant polishing can be recommended in order to diminish color changes.