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OBJECTIVE: The aim of this study was to evaluate the ability of PTR-LUM (The Canary System, CS), laser fluorescence (DIAGNOdent, DD), LED fluorescence (Spectra), and visual inspection (ICDAS II) to detect natural decay around bonded amalgam restorations in vitro. METHODS: Seventeen extracted human molars and premolars, consisting of visually healthy (n=5) and natural cavitated (n=12) teeth were selected. For the carious teeth, caries was removed leaving some decayed tissue on the floor and or wall of the preparation. For sound teeth, 3 mm. deep cavity preparations were made and teeth were restored with bonded-amalgam restorations. Thirty-six sites (13 sound sites; 23 carious sites) were selected. CS and DD scans were performed in triplicate at 2, 1.5, 0.5, and 0 mm away from the margin of the restoration (MOR). Spectra images were captured for the entire surface, and dentists blinded to the samples provided ICDAS II scoring. RESULTS: Canary Numbers (Mean±SE) for healthy and carious sites at 2, 1.5, 0.5, and 0 mm from the MOR ranged from 12.9±0.9 to 15.4±0.9 and 56.1±4.0 to 56.3±2.0, respectively. DD peak values for healthy and carious sites ranged from 4.7±0.5 to 13.5±2.99, and 16.7±3.7 to 24.5±4.4, respectively. For CS and DD, sensitivity/specificity for sites at 2.0, 1.5, 0.5, 0 mm ranged from 0.95-1.0/0.85-1.0, and 0.45-0.74/0.54-1.0, respectively. For ICDAS II, sensitivity and specificity were 1.0 and 0.17, respectively. For Spectra, data and images were inconclusive due to signal intereference from the amalgam restoration. CONCLUSIONS: Using this in-vitro model, CS and DD were able to differentiate between sound and carious tissue at the MOR, but larger variation, less reliability, and poorer accuracy was observed for DD. Therefore, CS has the potential to detect secondary caries around amalgam restorations more accurately than the other investigated modalities.
RESUMO
INTRODUCTION: The aim of this study was to correlate lesion depth of natural caries, measured with Polarized Light Microscopy (PLM), to Canary Numbers (CN) derived from The Canary System™ (CS), numerical readings from DIAGNOdent (DD), and lesion scores from ICDAS II. METHODS: A total of 20 examination sites on extracted human molars and premolars were selected. The selected examination sites consisted of healthy and enamel caries on smooth and occlusal surfaces of each tooth. Two blinded dentists ranked each examination site using ICDAS II and the consensus score for each examined site was recorded. The same examination sites were scanned with CS and DD, and the CN and DD readings were recorded. After all the measurements were completed, the readings of the three caries detection methods were validated with a histological method, Polarized Light Microscopy (PLM). PLM performed by blinded examiners was used as the 'gold standard' to confirm the presence or absence of a caries lesion within each examined site and to determine caries lesion depth. RESULTS: Pearson's coefficients of correlation with caries lesion depth of CNs, DD readings and ICDAS scores were 0.84, 0.21 and 0.77, respectively. Mean ± SD CN for sound sites (n=3), caries lesion depths <800 µm (n=11), and caries lesion depths >800 µm (n=6) were 11±1, 55±15, and 75±22, respectively. Mean ± SD DD readings for sound sites, caries lesion depths <800 µm, and caries lesion depths >800 µm were 1±1, 7±11, and 8±9, respectively. Mean ± SD ICDAS II scores for sound sites, caries lesion depths <800 µm, and caries lesion depths >800 µm were 0±0, 2±1, and 2±1, respectively. The intra-operator repeatability for the Canary System was .953 (0.913, 0.978). CONCLUSION: This study demonstrated that the CS exhibits much higher correlation with caries lesion depth compared to ICDAS II and DD. CS may provide the clinician with more information about the size and position of the lesion which might help in monitoring or treating the lesion.The present extracted tooth study found that The Canary System correlates with caries lesion depth more accurately that ICDAS II and DIAGNOdent.