Enamel surface roughness after orthodontic adhesive removal: an in vitro study comparing four clearance methods

Area of Science:

• Dental Materials Science
• Orthodontic Technology
• Biomaterials Surface Analysis

Background:

• Adhesive remnant removal is critical for successful orthodontic treatment outcomes.
• Achieving a smooth enamel surface post-debonding minimizes iatrogenic damage and improves aesthetics.
• Current methods vary in efficiency and their impact on enamel surface integrity.

Purpose of the Study:

• To evaluate four different clearance methods (CM) for orthodontic adhesive remnants.
• To determine which method yields the smoothest enamel surface.
• To assess the time efficiency of each clearance method.

Main Methods:

• Seventy-five premolars were used, with 60 undergoing bracket bonding and removal.
• Four clearance methods were tested: carbide bur (CB), carbide bur with titanium nitride treatment + fine carbide bur (CBCB), glass fiber-reinforced composite bur (GFCB), and zirconia bur + GFCB.
• Enamel surface roughness (Ra, Rq, Rt) was measured using atomic force microscopy, and Enamel Damage Index (EDI) was assessed via scanning electron microscopy.

Main Results:

• Significant differences in enamel roughness (Ra, Rq, Rt) were found across all methods (p<0.0001).
• GFCB produced the smoothest enamel surface across all roughness parameters.
• CBCB was the fastest method (mean 49s) with satisfactory enamel roughness, while GFCB was the slowest (mean 116s).

Conclusions:

• Carbide bur (CB) is the fastest but results in the roughest enamel.
• The combination of carbide bur with titanium nitride surface treatment and fine carbide bur (CBCB) is a rapid and effective method for adhesive remnant removal, yielding acceptable enamel smoothness.
• Glass fiber-reinforced composite bur (GFCB) offers superior surface smoothness but requires more time.