Monitoring Extracted Teeth Treated with Silver Diamine Fluoride using PTR-LUM

Objectives: This study evaluated the ability of PTR-LUM (The Canary System, CS), and visual examination (ICDAS II) to monitor changes in extracted teeth treated with Silver Diamine Fluoride (SDF) for 100 days in vitro.
Methods: Fifteen extracted human molars and premolars, consisting of five teeth with an ICDAS 0 surface, 5 teeth with ICDAS 1 -2 lesions on one surface and 5 teeth with natural-cavitated lesions were stored in distilled water until one day before the study commenced. One day prior to commencing, the teeth were placed in artificial saliva. SDF (Elevate Oral Care) was applied on the lesion, allowed to dry and the tooth placed back into the artificial saliva. All smooth tooth surfaces were scanned using CS and photographed before starting the study and on day 1, 6, 40, 60 and 100. On the first day following the application of SDF the teeth were placed back into fresh artificial saliva. The average Canary Number (CN) for each smooth surface was used in the covariance and correlation analysis.
Results: The CN increased on all tooth surfaces in all groups over time after SDF application. Covariance and correlation coefficient increased with increase in ICDAS ranking. CN increased primarily as silver ions diffused into the tooth structure, which caused an increase in PTR signal. Some of the ICDAS 0 tooth surfaces did pick up SDF and changed colour over time and some of the ICDAS 1-2 teeth did not pick up SDF.
Conclusions: It appears that SDF or its components become incorporated into lesions and CS can detect these changes even if colour change aren’t seen. Additional research should assess:
If SDF is being picked up by adjacent teeth or surfaces.
Does SDF impact the structural integrity of ICDAS 1 or 2 lesions and will it inhibit remineralization.