The diagnostic efficacy of quantitative light-induced fluorescence in detection of dental caries of primary teeth.

OBJECTIVES: To evaluate a quantitative light-induced fluorescence (QLF) caries detection method using a portable device under clinical conditions and present a QLF scoring index (QS-index) for primary teeth. METHODS: A total of 878 tooth surfaces (proximal and occlusal) of 44 children were studied. After visual inspection and radiographic examination, images of dental caries captured with the QLF device were classified according to caries progression stages and analyzed with a specialized software. Cut-off values, sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) were calculated for the QLF parameters: fluorescence loss (ΔF) and bacterial activity (ΔR). The reliability of logistic regression model to combine ΔF and ΔR was evaluated by the AUROC. RESULTS: QLF parameters showed a good sensitivity (0.72-0.91), specificity (0.74-0.96), and AUROC (0.861-0.940). The AUROC of logistic regression model (0.90-0.957) was higher than ΔF or ΔR average alone in all types of carious lesions. Every level of the QS-index was properly defined to represent the progression of dental caries with corresponding statistical significance. CONCLUSIONS: The reliability of QLF for dental caries detection in primary teeth was similar to or slightly higher than that of the traditional diagnostic methods of visual inspection or radiographic examination in clinical conditions. CLINICAL SIGNIFICANCE: The results of QLF were reliable in detecting all types of dental caries in primary teeth. The QLF method can provide visual images as well as quantitatively analyze the carious lesion.

Can red fluorescence be useful in diagnostic decision making of residual dentin caries?

INTRODUCTION: A diagnosis based on traditional methods can differ under the same tooth condition. Additional diagnostic tools are required to overcome this limitation. QLF technology is a viable method for detecting residual caries and is increasingly being used to detect dentin-level residual caries. In this study we used the Qraypen (AIOBIO, Seoul, Korea) to investigate the usefulness of the QLF technology for diagnosing controversial cases. CASE 1: A 31-year-old man presented with pain in the left mandibular first molar. The old restoration and severe dental caries were removed as much as possible using traditional visual and tactile senses. The area of treatment was photographed using the Qraypen. We concluded that endodontic treatment was preferable based on the Qraypen findings combined with diagnostic information. CASE 2: A 67-year-old man presented with discomfort in the first molar on the right mandible. Most of the existing restoration and carious debris were removed. Black discoloration was observed around and within the crack line, but with no red fluorescence. Based on the results of these examinations we decided that a minimally invasive dentistry approach was appropriate. CONCLUSION: Using QLF technology is more objective and accurate than other methods of determining the removal end point and detecting healthy marginal dentin for successful restoration.

Early caries detection methods according to the depth of the lesion: An in vitro comparison.

PURPOSE: The aims of this study were to estimate the histological and optical changes of early carious lesions according to the duration of demineralization and to compare the efficacy to detect early carious lesions of a quantitative light-induced fluorescence (QLF) system with a spectrophotometer according to the lesion depth. METHODS: Eighty-four bovine enamel specimens were immersed in demineralizing gel for six distinct days. The severities of lesions were evaluated by lesion depths (Ld) by polarized light microscopy, fluorescence loss (ΔF) using QLF, and brightness (ΔL*) by spectrophotometry. The relationships between Ld, ΔF, and ΔL*were analyzed. RESULTS AND CONCLUSION: Ld tended to be significantly deeper according to the demineralizing period (p < 0.05). The ΔF significantly decreased (p < 0.05) and the ΔL* significantly increased with increasing the demineralizing period (p < 0.05). More shallow lesions (Ld≤200 µm) showed a strong relationship between ΔF and Ld (r = -0.898, p < 0.001), while there was a strong relationship between ΔL* and Ld in deeper lesions (Ld>200 µm) (r = 0.858, p < 0.001). Our findings show that QLF system is a more efficient device for shallow early caries detection and that the spectrophotometer is a more stable device for the detection of deeper lesions.

Validation of fluorescence devices for evaluation of white spot lesions in orthodontic patients.

AIM: To clinically validate the fluorescence devices, DIAGNOdent Pen™ and Vista Proof™ for the evaluation of non-cavitated white spot lesions (WSL) in orthodontic patients and using direct visual examination after the brackets removal, as the gold standard. METHODS: The sample consisted of 31 patients, 13-28 years old, under fixed appliance orthodontic treatment. Teeth (N = 619) were evaluated with the brackets on, after cleaning and air drying, by direct, indirect visual examination and using the DIAGNOdent Pen™ device. After debonding with direct visual examination and the Vista Proof™ device. WSL were scored with the Gorelick Index for visual examination. The fluorescence devices were validated by calculating sensitivity, specificity and accuracy while ROC curves and area under the curve were used for comparison among the examination methods. RESULTS: Among the different diagnostic methods, visual examination recorded the highest degree of accuracy. The performance of the fluorescence devices was poor compared with that of the visual methods for mild WSL, while for more extended lesions no difference was found. A comparison between the validity of the two devices' showed no statistically significant difference. CONCLUSIONS: The validity of DIAGNOdent Pen™ and Vista Proof™ for the chairside diagnosis and quantification of non-cavitated WSL in orthodontic patients was moderate, and no better as compared to the visual diagnostic methods. The fluorescence devices performed similarly to the visual examination for more extended WSL and poorer for milder ones. Validity between the two devices did not differ.

Diagnostic Accuracy of a Bioluminescence System for the Assessment of Caries Activity on Occlusal Surfaces.

OBJECTIVE: Assessment of caries lesion activity is usually performed using visual-tactile criteria. A new approach is to use a system consisting of a photoprotein, which is specific for free calcium ions, along with an integrated camera that visualizes the elevated calcium ions on the lesion as a light signal (bioluminescence). This study aimed to evaluate the reproducibility and diagnostic accuracy of a newly developed bioluminescence system to assess caries lesion activity on occlusal surfaces in vitro. MATERIALS AND METHODS: Ninety-four extracted permanent teeth with sound surfaces and both active and inactive caries lesions were included. The extent and activity of the investigation sites were classified visually according to the International Caries Detection and Assessment System. Digital images of the teeth were produced by the bioluminescence system and the images were analyzed for the presence of caries activity (the bioluminescent areas at the investigation sites). The images were reanalyzed after 4 weeks. Teeth were hemisected and methyl red dye was applied on the sections to validate lesion activity histologically. RESULTS: Agreement between the bioluminescence readings was shown by κ values of 0.802-0.917. A significant positive correlation (p < 0.001) was found across all methods (rs 0.618-0.811). Sensitivity and specificity for activity assessment using histology as the gold standard (cut-off: active/inactive) were, respectively, 83.6 and 85.0% for the visual assessment, and 92.5 and 90.0% for the bioluminescence method. Comparison of areas under the receiver-operating characteristic curves showed no significant difference between the visual and bioluminescence systems (p = 0.094). CONCLUSION: The bioluminescence system demonstrated high in vitro reproducibility and good diagnostic accuracy for activity assessment of caries lesions on occlusal surfaces which were not significantly different from the values obtained in the visual assessment.

Determining Caries Activity Using Oratest Among 12-to 15-year-old Children.

PURPOSE: Dental caries is the primary pathological cause of early tooth loss in children, which may lead to malnutrition and other health problems. Identification of patients with active carious lesions and at high risk for caries can help to dramatically decrease the disease prevalence. Thus, recognising the importance of early diagnosis of caries, the present study was carried out to correlate caries with oral microflora using Oratest among 12- to 15-year-old schoolchildren. MATERIALS AND METHODS: A total of 100 children were divided into control and test groups (n = 50) according to their DMFT scores. The test group was further divided into subgroup 1 (DMFT = 1-3) and subgroup 2 (DMFT > 3). Oratest, a caries activity test, was performed on all the children. Comparison among the variables was done using ANOVA and the independent sample t-test. RESULTS: Boys had lower DMFT values (1.35 ± 0.2) than did girls (1.67 ± 0.2) (p = 0.38), and the Oratest time was higher among boys (132.8 ± 0.5 min) than girls (126.4 ± 0.5 min) (p = 0.53). The control group had the highest mean Oratest time (172.7 ± 0.3 min), followed by subgroup 1 (97.8 ± 0.2 min), and subgroup 2 had the lowest Oratest time (68.5 ± 14.8 min). A statistically significant negative correlation (r = -0.893) was found between the mean DMFT and the Oratest time (p < 0.001), ie, they were inversely related to each other. CONCLUSION: An inverse relationship exists between Oratest and DMFT score.

Clinical performance of fluorescence-based methods for detection of occlusal caries lesions in primary teeth.

We aimed to investigate the performance of fluorescence-based methods (FBMs), compared to visual inspection after histological validation, in detecting and assessing the activity status of occlusal carious lesions in primary teeth. One examiner evaluated 50 primary molars close to exfoliation in 24 children. Teeth were assessed using quantitative light-induced fluorescence (QLF) and pen-type laser fluorescence (LFpen). After exfoliation, histological validation was performed. Teeth were cut and sections were evaluated for lesion depth and activity status (after utilization of a pH indicator) under a stereomicroscope. Parameters related to the performance of the methods in detecting caries lesions at two thresholds (initial and dentin lesions) were calculated. Regarding the activity status, lesions were classified into sound+inactive or active, and the area under the ROC curve and the diagnostic odds ratio values of the methods were calculated and compared. Evaluation of red fluorescence using QLF presented higher sensitivity but lower specificity than visual inspection in detecting dentin caries lesions. However, QLF considering different parameters and LFpen had similar performance to that obtained with visual inspection. Regarding activity assessment, all FBMs and visual inspection also presented similar performance. In conclusion, FBMs did not prove advantageous for the detection and activity assessment of occlusal caries lesions in primary molars when compared to visual inspection.

Examiner's experience and the outcome interpretation of ICDAS and Nyvad's system - a prospective in vitro study.

OBJECTIVE: To evaluate, prospectively, the influence of examiner's experience in interpreting and applying the caries detection systems ICDAS (IC) and Nyvad (NY). MATERIAL AND METHODS: Twelve second-year undergraduate dental students (UG) and 12 postgraduates (PG) MSc level analysed and codified 77 clinical dental caries photographs at three different moments: initially, without any training; after one week of receiving training through a theoretical class; and after two years. Reproducibility and correlation was evaluated; sensitivity, specificity and area under ROC curve (AUC) were dichotomized according to the presence of cavitation (IC) and in relation to disease activity (NY). RESULTS: IC presented good kappa values for the first two evaluations. Both criteria resulted in good Spearman's correlation after two years (IC = UG: 0.89; PG: 0.93/NY = UG: 0.81; PG: 0.82). Sensitivity, specificity and AUC were statistically higher in the third evaluation by UG for Nyvad. CONCLUSIONS: ICDAS criteria seem to be instinctively understood by students without clinical experience. Nyvad's concepts performed better after two years where the students deepened their theoretical knowledge and experienced clinical practice, collaborating with the identification of activity signs.

Association between quantitative measures obtained using fluorescence-based methods and activity status of occlusal caries lesions in primary molars.

BACKGROUND: Fluorescence-based methods (FBM) can add objectiveness to diagnosis strategy for caries. Few studies, however, have focused on the evaluation of caries activity. AIM: To evaluate the association between quantitative measures obtained with FBM, clinical parameters acquired from the patients, caries detection, and assessment of activity status in occlusal surfaces of primary molars. DESIGN: Six hundred and six teeth from 113 children (4-14 years) were evaluated. The presence of a biofilm, caries experience, and the number of active lesions were recorded. The teeth were assessed using FBM: DIAGNOdent pen (Lfpen) and Quantitative light-induced fluorescence (QLF). As reference standard, all teeth were evaluated using the ICDAS (International Caries Detection and Assessment System) associated with clinical activity assessments. Multilevel regressions compared the FBM values and evaluated the association between the FBM measures and clinical variables related to the caries activity. RESULTS: The measures from the FBM were higher in cavitated lesions. Only, ∆F values distinguished active and inactive lesions. The LFpen measures were higher in active lesions, at the cavitated threshold (56.95 ± 29.60). Following regression analyses, only the presence of visible biofilm on occlusal surfaces (adjusted prevalence ratio = 1.43) and ∆R values of the teeth (adjusted prevalence ratio = 1.02) were associated with caries activity. CONCLUSION: Some quantitative measures from FBM parameters are associated with caries activity evaluation, which is similar to the clinical evaluation of the presence of visible biofilm.

Clinical performance of fluorescence-based methods for detection of occlusal caries lesions in primary teeth

Abstract We aimed to investigate the performance of fluorescence-based methods (FBMs), compared to visual inspection after histological validation, in detecting and assessing the activity status of occlusal carious lesions in primary teeth. One examiner evaluated 50 primary molars close to exfoliation in 24 children. Teeth were assessed using quantitative light-induced fluorescence (QLF) and pen-type laser fluorescence (LFpen). After exfoliation, histological validation was performed. Teeth were cut and sections were evaluated for lesion depth and activity status (after utilization of a pH indicator) under a stereomicroscope. Parameters related to the performance of the methods in detecting caries lesions at two thresholds (initial and dentin lesions) were calculated. Regarding the activity status, lesions were classified into sound+inactive or active, and the area under the ROC curve and the diagnostic odds ratio values of the methods were calculated and compared. Evaluation of red fluorescence using QLF presented higher sensitivity but lower specificity than visual inspection in detecting dentin caries lesions. However, QLF considering different parameters and LFpen had similar performance to that obtained with visual inspection. Regarding activity assessment, all FBMs and visual inspection also presented similar performance. In conclusion, FBMs did not prove advantageous for the detection and activity assessment of occlusal caries lesions in primary molars when compared to visual inspection.

Clinical Assessment of a New Caries Activity Test Using Dental Plaque Acidogenicity in Children under Three Years of Age.

OBJECTIVES: The aim of this study was to assess the validity of a new caries activity test that uses dental plaque acidogenicity in children with deciduous dentition. STUDY DESIGN: Ninety-two children under the age of three years old underwent clinical examination using the dft index and examinations with two caries activity tests. Plaque samples for the new Cariview(®) test and the saliva sample for the conventional Dentocult SM(®) test were collected, incubated, and scored according to each manufacturers' instruction. The data were analysed using ANOVA and Spearman correlation analyses to evaluate the relationships between the test results and the caries experience. RESULTS: The mean dft index of all of the subjects was 4.73, and 17.4% of the subjects were caries-free. The levels of caries risk based on the new Cariview test score significantly increased with the caries experience (p < 0.01). The test results revealed a stronger correlation with caries indices (dft and dt index) than the conventional SM colony counting method (r = 0.43, r = 0.39, p < 0.01). CONCLUSIONS: The new caries activity test to analyse the acidogenic potential of whole microorganisms from dental plaques can be used to evaluate caries risk in children with deciduous teeth.

Evaluation of resin infiltration using quantitative light-induced fluorescence technology.

OBJECTIVES: To determine whether quantitative light-induced fluorescence (QLF) technology can be used to classify the colour of teeth specimens before and after resin infiltration (RI) treatment, and calculate the correlation between the ΔF value and colour difference (ΔE) in fluorescence images of the specimens obtained using a QLF-digital (QLF-D) device. METHODS: Sixty sound bovine permanent teeth specimens were immersed in demineralized solution. Two exposed windows were formed in each specimen, and RI treatment was applied to one of them. The ΔE values were obtained for the differences between a sound tooth surface (SS), an early dental caries surface (ECS) and an ECS treated with RI (RS) in white-light and fluorescence images obtained using QLF-D, respectively. The ΔF value was obtained from fluorescence images using dedicated software for QLF-D. The mean differences between the ΔE values obtained from the white-light and fluorescence images were analyzed by paired t-test. Pearson correlation analysis and Bland-Altman plots were applied to the differences between the ΔF value for ECS (ΔFSS-ECS) and the ΔE value between SS and ECS (ΔESS-ECS), and between the ΔF value for RS (ΔFSS-RS) and the ΔE value between SS and RS (ΔESS-RS) in fluorescence images. RESULTS: The ΔE values obtained from fluorescence images were three times higher than the ΔE values obtained from white-light images (p<0.001). Significant correlations were confirmed between ΔESS-ECS and ΔFSS-ECS (r=-0.492, p<0.001) and between ΔESS-RS and ΔFSS-RS (r=-0.661, p<0.001). CONCLUSION: QLF technology can be used to confirm the presence of RI in teeth.

Proximal caries lesion detection using the Canary Caries Detection System: an in vitro study.

OBJECTIVE: This study investigated the accuracy of the Canary System (CS) to detect proximal caries lesions in vitro, and compared it with conventional methods: International Caries Detection and Assessment System (ICDAS) II and bitewing radiography (BW). METHODS: Visible proximal surfaces of extracted human teeth were assessed by ICDAS-II before setting them in five manikin mouth models. Then contacting proximal surfaces in mouth models were assessed by BW and CS. Histological validation with polarized-light microscopy served as a gold standard. Pairwise comparisons were performed on area under the curve (AUC), sensitivity, and specificity of the three methods, and corrected using Bonferroni's method. Sensitivities and specificities were compared using a test of proportions and AUC values were compared using DeLong's method. RESULTS: The CS presented significantly higher sensitivity (0.933) than ICDAS-II (0.733, P = 0.01) and BW (0.267, P < 0.001), and ICDAS-II higher sensitivity than BW (P < 0.001). There were no significant differences between their specificity values: 0.825 (CS), 0.65 (ICDAS-II), and 0.875 (BW). The AUC of CS (0.862) was significantly higher than of ICDAS-II (0.681, P < 0.001) and BW (0.577, P < 0.001). CONCLUSION: The CS demonstrated greater accuracy in detecting proximal lesions than ICDAS-II and BW, although without significantly higher specificity.

Impact of different magnification levels on visual caries detection with ICDAS.

OBJECTIVES: The aim of this in vitro study was to examine the effect of different levels of magnification on the accuracy and reliability of visual caries detection using ICDAS criteria. METHODS: Occlusal surfaces of 100 extracted molars were assessed by 14 examiners (3rd and the 4th year dental students and dentists) using no magnification aids, a 2.5× Galilean loupe, a 4.5× Keplerian loupe, or a surgical microscope with 10× magnification. The assessments were repeated on a different day. Sensitivity, specificity, AUC and reliabilities were calculated according to the gold standard of histology. RESULTS: We found that with increasing magnification, the number of surfaces rated as "sound" (ICDAS code 0) decreased, while the number of surfaces with a localized enamel breakdown (ICDAS code 3) increased. While the sensitivities increased, the values of the specificities decreased to an unacceptably low level irrespective of the clinical experience of the examiners. CONCLUSIONS: ICDAS seems to be optimized for natural vision up to 2.0× magnification and not for high magnifications. The use of powerful magnification in visual caries detection involves the risk of unnecessary and premature invasive treatment. CLINICAL SIGNIFICANCE: This paper discusses when it does and does not make sense to use magnification devices for visual caries detection using ICDAS criteria. Strong magnifications should be refrained from for this purpose.

Detection and diagnosis of the early caries lesion.

The purpose of this manuscript is to discuss the current available methods to detect early lesions amenable to prevention. The current evidenced-based caries understanding, based on biological concepts, involves new approaches in caries detection, assessment, and management that should include non-cavitated lesions. Even though the importance of management of non-cavitated (NC) lesions has been recognized since the early 1900 s, dental caries has been traditionally detected at the cavitation stage, and its management has focused strongly on operative treatment. Methods of detection of early carious lesions have received significant research attention over the last 20 years. The most common method of caries detection is visual-tactile. Other non-invasive techniques for detection of early caries have been developed and investigated such as Quantitative Light-induced Fluorescence (QLF), DIAGNOdent (DD), Fibre-optic Transillumination (FOTI) and Electrical Conductance (EC). Based on previous systematic reviews, the diagnosis of NCCLs might be more accurately achieved in combination of the visual method and the use of other methods such as electrical methods and QLF for monitoring purposes.

An in vitro comparison of quantitative light-induced fluorescence-digital and spectrophotometer on monitoring artificial white spot lesions.

PURPOSE: The aim of this study was to evaluate the efficacy of quantitative light-induced fluorescence-digital (QLF-D) compared to a spectrophotometer in monitoring progression of enamel lesions. METHODS: To generate artificial caries with various severities of lesion depths, twenty bovine specimens were immersed in demineralizing solution for 40 days. During the production of the lesions, repeat measurements of fluorescence loss (ΔF) and color change (ΔE) were performed in six distinct stages after the demineralization of the specimens: after 3, 5, 10, 20, 30, and 40 days of exposure to the demineralizing solution. Changes in the ΔF values in the lesions were analyzed using the QLF-D, and changes in the ΔE values in lesions were analyzed using a spectrophotometer. The repeated measures ANOVA of ΔF and ΔE values were used to determine whether there are significant differences at different exposure times in the demineralizing solution. Spearman's rank correlation coefficient was analyzed between ΔF and ΔE. RESULTS AND CONCLUSION: The ΔF values significantly decreased based on the demineralizing period (p<0.001). Relatively large changes in ΔF values were observed during the first 10 days. There were significant changes in L(*), a(*), b(*), and ΔE values in lesions with increasing demineralizing duration (p<0.001). A strong correlation was observed between ΔF and ΔE with p=-0.853 (p<0.001). The results support the efficacy of QLF-D in monitoring color changes. Our findings demonstrate that QLF-D are a more efficient and stable tool for early caries detection.

Validation of quantitative light-induced fluorescence-digital (QLF-D) for the detection of approximal caries in vitro.

OBJECTIVES: Detection of approximal caries lesions can be difficult due to their anatomical position. This study aimed to assess the ability of the quantitative light-induced fluorescence-digital (QLF-D) in detecting approximal caries, and to compare the performance with those of the International Caries Detection and Assessment System II (ICDAS II) and digital radiography (DR). METHODS: Extracted permanent teeth (n=100) were selected and mounted in pairs. The simulation pairs were assessed by one calibrated dentist using each detection method. After all the examinations, the teeth (n=95) were sectioned and examined histologically as gold standard. The modalities were compared in terms of sensitivity, specificity, areas under receiver operating characteristic curves (AUROC) for enamel (D1) and dentine (D3) levels. The intra-examiner reliability was assessed for all modalities. RESULTS: At D1 threshold, the ICDAS II presented the highest sensitivity (0.80) while the DR showed the highest specificity (0.89); however, the methods with the greatest AUC values at D1 threshold were DR and QLF-D (0.80 and 0.80 respectively). At D3 threshold, the methods with the highest sensitivity were ICDAS II and QLF-D (0.64 and 0.64 respectively) while the method with the lowest sensitivity was DR (0.50). However, with regard to the AUC values at D3 threshold, the QLF-D presented the highest value (0.76). All modalities showed to have excellent intra-examiner reliability. CONCLUSIONS: The newly developed QLF-D was not only able to detect proximal caries, but also showed to have comparable performance to the visual inspection and radiography in detecting proximal caries. CLINICAL SIGNIFICANCE: QLF-D has the potential to be a useful detection method for proximal caries.

In vitro evaluation of laser fluorescence devices for caries detection through stereomicroscopic imaging.

The aims of this study were to determine the diagnostic accuracy and reproducibility of the laser fluorescence device (LF), and the relationship between laser fluorescence readings taken at the entrance of the fissure, ICDAS visual examination caries detection system and the histological depth of the lesion. Two hundred and forty teeth (122 human third molars and 118 bicuspids) were selected from 62 patients enrolled in the study. Visual and LF examinations (Diagnodent, Kavo, Biberach, Germany) of the occlusal surfaces were performed in vivo. After tooth extraction, histological sections were evaluated by stereomicroscopy in vitro. Statistical analysis was performed using multiple statistical methods (SPSS ver. 17). Intra-examiner reproducibility for the LF measurements was excellent: intra-class-correlation coefficient (ICC) for LF was 0.957. Kappa values for each examiner's reproducibility were 0.74-0.82. The diagnostic performance of the LF device gave a good overall diagnostic accuracy according to ICDAS II codes and histological values as indicated by the area under the ROC curve of 0.707 and 0.709 respectively. The results of the study showed acceptable diagnostic accuracy for the laser fluorescence device. This supports the view that dentists can be site specific in applying fluorescence-based devices to multiple discrete sites within the same surface. In conclusion, these diagnostic methods have different characteristics, indications and limitations for use. In order to detect caries on occlusal surfaces thoroughly, a combination of methods would be the best practice moderated by clinical knowledge and experience.

Use of new minimum intervention dentistry technologies in caries management.

Preservation of natural tooth structure requires early detection of the carious lesion and is associated with comprehensive patient dental care. Processes aiming to detect carious lesions in the initial stage with optimum efficiency employ a variety of technologies such as magnifying loupes, transillumination, light and laser fluorescence (QLF® and DIAGNOdent® ) and autofluorescence (Soprolife® and VistaCam®), electric current/impedance (CarieScan(®) ), tomographic imaging and image processing. Most fluorescent caries detection tools can discriminate between healthy and carious dental tissue, demonstrating different levels of sensitivity and specificity. Based on the fluorescence principle, an LED camera (Soprolife® ) was developed (Sopro-Acteon, La Ciotat, France) which combined magnification, fluorescence, picture acquisition and an innovative therapeutic concept called light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT). This article is rounded off by a Soprolife® illustration about minimally or even non-invasive dental techniques, distinguishing those that preserve or reinforce the enamel and enamel-dentine structures without any preparation (MIT1- minimally invasive therapy 1) from those that require minimum preparation of the dental tissues (MIT2 - minimally invasive therapy 2) using several clinical cases as examples. MIT1 encompasses all the dental techniques aimed at disinfection, remineralizing, reversing and sealing the caries process and MIT2 involves a series of specific tools, including microburs, air abrasion devices, sonic and ultrasonic inserts and photo-activated disinfection to achieve minimal preparation of the tooth. With respect to minimally invasive treatment and prevention, the use of lasers is discussed. Furthermore, while most practices operate under a surgical model, Caries Management by Risk Assessment (CaMBRA) encourages a medical model of disease prevention and management to control the manifestation of the disease, or keep the oral environment in a state of balance between pathological and preventive factors. Early detection and diagnosis and prediction of lesion activity are of great interest and may change traditional operative procedures substantially. Fluorescence tools with high levels of magnification and observational capacity should guide clinicians towards a more preventive and minimally invasive treatment strategy.

Oratest: a new concept to test caries activity.

Caries activity tests are based on the concept of a specific odontogenic infection, the principle causative organism being streptococci mutans. Their predominance is attributed to its acidogenic and aciduric nature after a selective growth advantages over the other non- acid tolerant organisms. Many studies on caries activity are aimed at finding relevant microorganisms. Till date, the ideal method to evaluate in terms of sensitivity, specialization and reliability has not been found. Many of these caries activity tests require extensive work up time and additional equipment. Rosenberg et al. in 1989 developed Oratest, a simple, economical, non- invasive and less time-consuming test for estimating the oral microbial level. The test is simple and consists of rinsing the mouth with 10 ml of sterile milk, 3 ml of which is mixed with 0.12 ml of 0.1% methylene blue dye and observed for colour change. The present study sample consists of twenty five children with dental caries and twenty five controls, free of caries, gingivitis and other oral ailments. This study is being conducted in the department of Oral Pathology & Microbiology and is in the preliminary phase so further results are awaited.