Enamel colour changes at debonding and after finishing procedures using five different adhesives

Area of Science:

• Dental Materials Science
• Orthodontics
• Biomaterials

Background:

• Orthodontic bonding adhesives are crucial for bracket placement.
• Adhesive discolouration can impact orthodontic treatment aesthetics.
• Photoageing simulates in vivo conditions to assess material stability.

Purpose of the Study:

• To evaluate enamel colour alteration in five orthodontic bonding adhesives.
• To assess discolouration after simulated photoageing (in vivo).
• To compare digital colour measurements of adhesive systems.

Main Methods:

• Five orthodontic adhesives (Transbond XT, Eagle Bond, Light Bond, Blugloo, Unite) bonded to 75 premolars.
• Artificial accelerated photoageing for 24 hours.
• Colourimetric evaluation using Commission Internationale de l'Eclairage (CIE) L*a*b* parameters and DeltaE calculation before and after photoageing.

Main Results:

• All tested orthodontic adhesives showed minimal colour alteration after photoageing.
• The highest colour difference (DeltaE) was 1.51 +/- 1.15 in the Transbond XT group.
• No clinically significant colour changes (DeltaE > 3.7) were observed across all groups.

Conclusions:

• Photoageing does not induce clinically observable colour changes in the evaluated orthodontic bonding adhesives.
• The aesthetic performance of these adhesives is likely stable under simulated ageing conditions.
• Stainbuster polishing effectively removes enamel surface roughness, potentially improving light reflection and aesthetic outcomes.