Reliability of quantitative laser fluorescence analysis of smooth surface lesions adjacent to the gingival tissues

Monitoring enamel caries on resin-treated occlusal surfaces using quantitative light-induced fluorescence: an in vitro study

The aim of this study is to evaluate the ability of quantitative light-induced fluorescence (QLF) to monitor enamel caries lesions of different severity stages located on the occlusal surfaces of permanent teeth before and after treatment with resin infiltrant. Sixty extracted permanent teeth had one occlusal site selected and were categorized according to the International Caries Detection and Assessment System (ICDAS) criteria. The teeth were divided into three groups (n = 20): ICDAS 1, ICDAS 2, and ICDAS 3. The teeth were assessed by a trained examiner using QLF in two phases: (A) before and (B) after treatment with resin infiltrant. The caries lesions were evaluated using the following QLF parameters: area (mm²); ΔF, fluorescence loss (%); and ΔQ, fluorescence loss integrated over the lesion area (%*mm²). The resin infiltrant (Icon™) was applied on the occlusal surface following the manufacturer's recommendations. The teeth were then sectioned and prepared for polarized light microscopy analysis. The penetration of resin infiltrant was measured with ImageJ. The groups showed a statistically significant difference in all QLF parameters before and after caries infiltration, with the reduction of fluorescence values posttreatment (p < 0.05). Infiltrant penetration was observed in all groups, with a statistical difference between all groups (p < 0.05). The reduction in QLF parameters after resin infiltration suggests that QLF is able to monitor enamel caries lesions of different severity stages located on the occlusal surfaces of permanent teeth before and after treatment with resin infiltrant.

Reliability and validity of FluoreCam for white-spot lesion detection: An in vitro study

AIM

In the present study, we tested the reliability and validity of a new light fluorescence device, the FluoreCam.

METHODS

Twenty-five human teeth were sectioned mesiodistally into halves. Group 1 (n=30) included specimens with either sound enamel or natural white-spot lesions (WSL). Group 2 (n=20) included specimens with sound enamel used to create artificial WSL. Using the FluoreCam, baseline scans of enamel surfaces were obtained under standardized conditions. Group1 was scanned again the next day. Group 2 specimens were covered with an acid-resistant nail polish, leaving a 2 × 6-mm enamel window exposed, immersed in Queiroz-solution (64 hours, 37°C/pH5 with agitation), and then scanned again. Random error of the repeated measurements (reliability) was determined using method errors and intraclass correlations (ICC). Systematic error and the ability to detect demineralization (validity) were tested using Wilcoxon signed-rank test.

RESULTS

Method errors for Group 1 replicates were .39 mm² (area), .72 pixels (intensity), and 5.69 pixels.mm² (impact). Group 2 method errors were consistently slightly higher than those of group 1. FluoreCam showed highly reliable measurements for group 1 (ICC: 0.93-0.98) and group 2 (ICC: 0.87-0.97). There were no statistically-significant systematic errors for either group (P>.05). In group 2, enamel demineralization was statistically significant in area (P<.001), intensity (P=.001), and impact (P<.001).

CONCLUSION

FluoreCam is highly reliable and valid for in vitro assessments of enamel demineralization.

In vitro Detection of Occlusal Caries on Permanent Teeth by a Visual, Light-Induced Fluorescence and Photothermal Radiometry and Modulated Luminescence Methods

Background: The paradigm shift towards the nonsurgical management of dental caries relies on the early detection of the disease. Detection of caries at an early stage is of unequivocal importance for early preventive intervention. Objective: The aim of this in vitro study is to evaluate the performance of a visual examination using the International Caries Detection and Assessment System (ICDAS) criteria, two quantitative light-induced fluorescence (QLF) systems - Inspektor™ Pro and QLF-D Biluminator™ 2 (Inspektor Research Systems B.V., Amsterdam, The Netherlands) - and a photothermal radiometry and modulated luminescence, The Canary System® (Quantum Dental Technologies, Toronto, Ont., Canada) on the detection of primary occlusal caries on permanent teeth. Methods: A total of 60 teeth with occlusal surface sites ranging from sound to noncavitated lesions (ICDAS 0-4) were assessed with each detection method twice in a random order. Histological validation was used to compare methods for sensitivity, specificity, percent correct, and the area under the receiver operating characteristic curve (AUC), at standard and optimum sound thresholds. Interexaminer agreement and intraexaminer repeatability were measured using intraclass correlation coefficients. Results: Interexaminer agreement ranged between 0.48 (The Canary System®) and 0.96 (QLF-D Biluminator™ 2). Intraexaminer repeatability ranges were 0.33-0.63 (The Canary System®) and 0.96-0.99 (QLF-D Biluminator™ 2). The sensitivity range was 0.75-0.96 while that of specificity was 0.43-0.89. The AUC were 0.79 (The Canary System®), 0.87 (ICDAS), 0.90 (Inspektor™ Pro), and 0.94 (QLF-D Biluminator™ 2). Conclusion: ICDAS had the best combination of sensitivity and specificity followed by QLF-D Biluminator™ 2 at optimum threshold.

Performance of a light fluorescence device for the detection of microbial plaque and gingival inflammation

OBJECTIVES

The hypothesis to be tested was that using the SOPROCARE system in fluorescence perio-mode allows scoring of microbial plaque that is comparable to the Turesky modification of the Quigley Hein plaque index (T-QH) and scoring of gingival inflammation comparable to the Silness and Löe gingival inflammation index (GI).

MATERIALS AND METHODS

Fifty-five subjects with various amounts of microbial plaque were recruited. The T-QH and GI index were recorded. SOPROCARE pictures were recorded in fluorescence perio-mode and in daylight mode. Finally, conventional digital photographs were taken. All pictures were assessed using the same criteria as described for the clinical indices.

RESULTS

The average T-QH was 1.1 ± 1.2 (mean ± SD). Scoring with SOPROCARE perio-mode led to a slightly higher average than the T-QH scores. SOPROCARE daylight mode and digital photography showed the highest plaque scores. The average GI index was 0.7 ± 0.9. SOPROCARE in perio-mode scored slightly lower. Linear regression fits between the different clinical indices and SOPROCARE scores were significantly different from zero demonstrating high goodness of fit.

CONCLUSIONS

The study demonstrated that the SOPROCARE fluorescence assessment tool in perio-mode allows reliable judgment of microbial plaque and gingival inflammation levels similar to the established Turesky-modified Quigley Hein index and the Silness and Löe gingival inflammation index. Training on plaque-free teeth will actually reduce scoring errors.

CLINICAL RELEVANCE

The SOPROCARE fluorescence tool in perio-mode provides reliable evaluation of microbial plaque and gingival inflammation for the dental clinician.

The effect of surface defects in early caries assessment using quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP)

OBJECTIVES

The purpose of this study was to consider the impact of surface defects on quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP) measures, in relationship to lesion depth.

METHODS

Simulated enamel carious lesions were developed on 45 extracted human teeth. Images of each tooth were captured with both QLF and MDP. The teeth were sectioned and lesion depth was measured with polarized light microscopy (PLM). Pearson correlations were computed using data from the 27 lesions which did not have surface loss, and then separately based upon the 18 lesions which did display surface loss. MDP variables ΔR and ΔX measure reflected light, whereas QLF variables ΔF and ΔQ measure fluorescence.

RESULTS

A strong correlation was identified between lesion depth and ΔF (r=-0.765, p<0.0001), and ΔQ (r=-0.827, p<0.0001) on intact lesions while a weak but suggestive, although non-significant, correlation was identified between average lesion depth and ΔR (r=0.369, p=0.059) and ΔX (r=0.595, p=0.0011). However, the corresponding correlation was not statistically significant, when lesions with surface loss were considered for QLF and MDP measures.

CONCLUSIONS

QLF measures ΔF and ΔQ were strongly correlated with lesion depth in lab-simulated lesions with no surface loss, but not among lesions with surface defects. The two MDP-associated measures, ΔR and ΔX, could not be said to differ significantly when lesions with and without surface defects were compared with lesion depth. Because intact lesions can be remineralized, accurate assessment of their status is imperative for caries treatment.

CLINICAL SIGNIFICANCE

Dental caries is still widely prevalent today. We now know that with early stage detection, remineralization can be accomplished. Being able to identify dental caries in its reversible stage (before physical surface loss) is paramount for the clinician to be able to treat the disease non-invasively.

Quantitative light fluorescence (QLF) and polarized white light (PWL) assessments of dental fluorosis in an epidemiological setting

Background

To determine if a novel dual camera imaging system employing both polarized white light (PWL) and quantitative light induced fluorescence imaging (QLF) is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods.

Methods

Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3) participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF) Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software.

Results

Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s) between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92.

Conclusions

The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

Performance of laser fluorescence devices and visual examination for the detection of occlusal caries in permanent molars

The aim of this study was to evaluate the diagnostic capabilities of a laser fluorescence tool DIAGNOdent (KaVo, Biberach, Germany) and two light-emitting diode fluorescence tools-Spectra Caries Detection Aid (AIR TECHNIQUES, Melville, NY), and SOPROLIFE light-induced fluorescence evaluator in daylight and blue florescence mode (SOPRO, ACTEON Group, La Ciotat, France)-in comparison to the caries detection and assessment system (ICDAS-II) in detection of caries lesions. In 100 subjects (age 23.4±10.6 years), 433 posterior permanent unrestored teeth were examined. On the occlusal surfaces, up to 1066 data points for each assessment method were available for statistical evaluation, including 1034 ICDAS scores (intra-examiner kappa=0.884). For the SOPROLIFE tool, a new caries-scoring system was developed. Per assessment tool each average score for one given ICDAS code was significantly different from the one for another ICDAS code. Normalized data linear regression revealed that both SOPROLIFE assessment tools allowed for best caries score discrimination followed by DIAGNOdent and Spectra Caries Detection Aid. The area under the receiver operating characteristics curve calculations showed the same grading sequence when cutoff point ICDAS codes 0-1-2 were grouped together. Sensitivity and specificity values at the same cutoff were calculated (DIAGNOdent 87/66, Spectra Caries Detection Aid 93/37, SOPROLIFE 93/63, SOPROLIFE blue fluorescence 95/55.).

Methods used by Dental Practice-based Research Network (DPBRN) dentists to diagnose dental caries

OBJECTIVES

To (1) identify the methods that dentists in The Dental Practice-Based Research Network (DPBRN) use to diagnose dental caries; (2) quantify their frequency of use and (3) test the hypothesis that certain dentist and dental practice characteristics are significantly associated with their use.

METHODS

A questionnaire about methods used for caries diagnosis was sent to DPBRN dentists who reported doing some restorative dentistry; 522 dentists participated. Questions included the use of dental radiographs, the dental explorer, laser fluorescence, air-drying and fiber-optic devices and magnification as used when diagnosing primary, secondary/recurrent or non-specific caries lesions. Variations on the frequency of their use were tested using multivariate analysis and Bonferroni tests.

RESULTS

Overall, the dental explorer was the instrument most commonly used to detect primary occlusal caries and caries at the margins of existing restorations. In contrast, laser fluorescence was rarely used to help diagnose occlusal primary caries. For proximal caries, radiographs were used to help diagnose 75%–100% of lesions by 96% of the DPBRN dentists. Dentists who use radiographs most often to assess proximal surfaces of posterior teeth were significantly more likely to also report providing a higher percentage of patients with individualized caries prevention (p=.040) and seeing a higher percentage of pediatric patients (p=.001).

CONCLUSION

The use of specific diagnostic methods varied substantially. The dental explorer and radiographs are still the most commonly used diagnostic methods..