Lower bonded retainers: survival and failure rates particularly considering operator experience

Area of Science:

• Orthodontics
• Dental Materials Science

Background:

• Lower bonded retainers are crucial for maintaining orthodontic treatment outcomes.
• Understanding retainer failure modes is essential for improving long-term stability.

Purpose of the Study:

• To retrospectively evaluate the frequency and types of lower bonded retainer failures.
• To investigate the correlation between operator experience and retainer failure rates.

Main Methods:

• Analysis of 1062 patient records with lower bonded retainers.
• Assessment of retainer type, failure instances, and timing.
• Comparison of failure rates between experienced orthodontists and postgraduate students.

Main Results:

• A high overall retainer failure rate of 34.9% was observed.
• Cuspid retainers (two bonding sites) demonstrated lower failure rates compared to multi-tooth retainers (six bonding sites).
• Bonding site detachment occurred in 22.8% of patients, with 17.9% experiencing total retainer loss; retainer fractures were rare (0.8%).
• Less experienced operators (postgraduate students) showed significantly higher failure rates than experienced orthodontists.

Conclusions:

• The study highlights a significant failure rate (34.9%) for lower bonded retainers in the studied cohort.
• Cuspid retainers appear to be more durable than 3-3 (all-inclusive) retainers.
• Reduced operator experience is a likely contributing factor to increased retainer failure rates.