Integrity testing of a smooth surface resin sealant around orthodontic brackets using a new Fluorescence-aided Identification Technique (FIT)

Objective: To investigate the integrity of a fluorescing resin-based sealant placed around orthodontic brackets using the Fluorescence-aided Identification Technique (FIT). Materials and Methods: Standard brackets were bonded to the buccal surfaces of 17 extracted sound permanent premolar crowns sealed with ProSeal®. Specimens were thermocycled (20,000 cycles, 5–55°C), and toothbrushing was simulated using an electric toothbrush and artificial aqueous toothpaste slurry. Changes in the sealed area were measured after one, two, three, and four alternating thermocycling-brushing cycles simulating 2 years of wear. Digital images were captured applying FIT (405 nm) using a digital camera–equipped stereomicroscope. ImageJ was used to measure sealant integrity and loss. Results: There was a time-dependent decrease in sealed areas by between 21% and 100% (mean 54%). The sealant lost its integrity immediately after the first cycle, and unfilled areas were observed in all samples. Conclusions: The analyzed sealant lost its integrity over time. Using the proposed FIT, sealed surfaces were easily verified and quantified.