Age of failed restorations: A deceptive longevity parameter

Area of Science:

• Dental materials science
• Clinical research methodology
• Biostatistics

Background:

• Assessing the longevity of dental restorations is crucial for evidence-based practice.
• Current methods for evaluating restoration survival may not accurately reflect long-term performance.
• There is a need to differentiate survival data based on restoration age versus established statistical methods.

Purpose of the Study:

• To compare and contrast dental restoration longevity data from different datasets.
• To investigate if restoration longevity calculated by Kaplan-Meier statistics differs from median survival time of failed restorations.

Main Methods:

• Utilized existing clinical datasets of dental restorations and an artificial dataset.
• Calculated restoration longevity using Kaplan-Meier statistics.
• Determined restoration longevity by calculating the median age of failed restorations.

Main Results:

• The median age of failed restorations can be a deceptive measure of restoration longevity.
• Longer longitudinal studies may inflate the median age of failed restorations.
• Materials with early failure rates may show lower median ages, inaccurately representing overall longevity compared to materials with later failures.

Conclusions:

• Reliable measures of dental restoration longevity are unavailable without complete placement and failure dates.
• Kaplan-Meier statistics remain the preferred method for calculating the longevity of dental restoration groups.