Effectiveness of Cleanliness Quantification Methods at Evaluating Clinically Used Dental-Instruments
Objectives: According to FDA reprocessing guidelines, every multi-use instrument should possess manufacturer specific cleaning instructions rendering the instruments safe and effective for reuse in clinical procedures. Previously, the ADA developed a dental-soil, which was used to soil diamond-instruments, and then methods were developed and tested for their ability to quantify the effectiveness of different cleaning methods at removing the dental-soil from the “dirty” instruments. The objective of this study was to use the previously developed cleanliness-quantification methods to evaluate clinically used diamond-rotatory-instruments and carbide-burs for cleanliness with-respect-to patient dentin tissue residues after multiple-uses and cleanings.
Methods: Multi-use carbide-burs and diamond-rotatory-instruments of different shapes and sizes were collected after being used clinically. In order to determine consistencies in the cleaning protocol, different batches of instruments were collected. All instruments were used in more than one clinical procedure and reprocessed by a standard cleaning protocol, which consisted of the following steps: sonicating the instruments in a general purpose cleaner for 30-minutes; drying; inspecting; and steam-sterilization through autoclaving. New instruments of the same type were subjected to the same standard cleaning protocol and used as controls for comparison. The instruments were assessed for protein and enamel/dentin residues by Phloxine-B staining and Alizarin-red-S assay, respectively.
Results: The study found the following: a) diamond-rotatory-instruments retained protein and enamel/dentin residues even after reprocessing, up to 500µg/ml; b) carbide-burs were cleaner than diamond-rotatory-instruments; c) variations were observed in different batches of cleaned instruments
Conclusions: This study showed that a previously developed method, which was shown to be effective at detecting the cleanliness of artificially-soiled dental instruments, was also effective at quantifying the cleanliness of clinically-used dental instruments. Alizarin-red-S assay alongside Phloxine-B staining and protein quantification may be used in methods to efficiently validate standard clinical cleaning instructions as part of an effective clinical reprocessing program.