Evaluation of Color Changes of White Spot Lesions Treated with Three Different Treatment Approaches: An In-Vitro Study

Published In: Dental Press Journal of Orthodontics
Publication Year: 2020

Study Design

This was an in-vitro experimental study. Researchers artificially created white spot lesions (WSLs) on extracted premolars and tested three treatment methods: nano-hydroxyapatite (nano-HA) toothpaste, microabrasion, and resin infiltration (Icon), with artificial saliva as a control group.

Funding Sources

The authors reported no commercial, proprietary, or financial interest in the products or companies described.

PICO Framework – What Was Studied and How?

Population:

• 60 extracted human premolars with artificially created WSLs.

Intervention:

• Resin infiltration treatment (Icon).

Comparison:

• Nano-hydroxyapatite toothpaste.

• Microabrasion treatment.

• Artificial saliva (control group).

Outcomes:

• Color change (ΔE value) measured with a dental spectrophotometer at baseline, immediately after treatment, and at 1, 3, and 6 months follow-up.

In Paragraph Form:
This study investigated artificially created white spot lesions on extracted human premolars to determine the effectiveness of resin infiltration in improving color appearance compared to nano-hydroxyapatite toothpaste, microabrasion, and no treatment. The main outcome measured was color change and stability over time, using spectrophotometric analysis.

Inclusion and Exclusion Criteria

Inclusion Criteria:

• Sound human premolars extracted for orthodontic reasons.

• Teeth free from stains, hypoplasia, fluorosis, decay, cracks, or defects.

Exclusion Criteria:

• Teeth with previous exposure to bleaching agents.

• Teeth with structural damage or visible defects.

Demographics and Sample Size

• Total: 60 premolars, divided equally into 4 groups of 15 each.

• Groups:

  • Resin infiltration (Icon)

  • Nano-HA toothpaste

  • Microabrasion

  • Control (artificial saliva)

Primary Outcome Variables and Results

Outcome: Color change (ΔE value).

• Baseline: No significant difference between groups (ΔE ≈ 15–16 for all).

• After treatment (0 months):

  • Control: ΔE = 15.79 ± 2.32

  • Microabrasion: ΔE = 11.99 ± 2.16

  • Nano-HA: ΔE = 10.96 ± 1.59

  • Resin infiltration: ΔE = 3.00 ± 0.59

• Follow-up (1, 3, and 6 months):

  • Resin infiltration maintained the lowest ΔE (≈ 2.84–2.87).

  • Nano-HA and microabrasion groups remained improved but less effective (≈ 10–12).

  • Control group showed no improvement (ΔE ≈ 15).

• Statistical significance: Differences were highly significant (p < 0.001).

Conclusions

Resin infiltration provided the most effective and long-lasting improvement in masking WSLs, restoring enamel appearance more effectively than nano-HA toothpaste or microabrasion. Improvements were stable up to 6 months. However, further long-term clinical trials are needed.

Discussion: Strengths and Limitations

Strengths:

• Direct comparison of non-invasive, minimally invasive, and invasive treatments.

• Standardized artificial WSL model for reproducibility.

• Longitudinal evaluation over six months.

Limitations:

• In-vitro setting (teeth outside the oral environment).

• Short follow-up period (6 months).

• Does not account for real-life factors such as diet, saliva composition, and oral microbiome.

The study concluded that resin infiltration achieves esthetically acceptable results (ΔE < 3.3), while nano-HA and microabrasion did not fully restore enamel appearance.

Visual Aids

Simple Chart: Color Change (ΔE) at Different Time Points

Citation