Adaptational changes in clear aligner fit with time

Area of Science:

• Orthodontics
• Biomaterials Science
• Dental Technology

Background:

• Clear aligners are increasingly used for orthodontic treatment.
• Assessing the long-term fit and adaptation of clear aligners during intraoral use is crucial for treatment efficacy.
• Previous studies have not comprehensively analyzed the changes in clear aligner fit over extended wear periods.

Purpose of the Study:

• To analyze the adaptational changes in clear aligner fit after intraoral usage at different time intervals.
• To quantify the gap width between clear aligners and tooth attachments over time.
• To determine the optimal wear period for maintaining clear aligner fit.

Main Methods:

• Eight clear aligner appliances were analyzed after intraoral use for 3, 7, 10, or 15 days.
• Acrylic imprints and scanning electron microscopy (SEM) were used to measure aligner fit (gap width) at five levels.
• Statistical analysis included analysis of variance (ANOVA) and Tukey's post hoc tests (P < .05).

Main Results:

• Significant differences in aligner fit were observed across different time points (P < .001).
• The smallest mean gap width was recorded at 15 days (176 ± 98 μm), indicating optimal fit.
• The largest mean gap width was observed at 7 days (269 ± 145 μm).

Conclusions:

• Clear aligner fit changes significantly with intraoral usage duration.
• A 15-day wear period appears to provide the best adaptation and minimal gap width between the aligner and attachment.
• These findings support the recommendation of a 15-day wear cycle for maintaining optimal clear aligner performance.