A Comparison of the Fluoride 'Paint- On' vs Tray Application Techniques for Enamel Remineralisation.

BACKGROUND: Fluoride gel treatment is not recommended for children < 6 years old due to its potential toxicity. Hence the aim of this study was to compare the effect of 1.23% acidulated-phosphate fluoride (APF) gel paint-on and the conventional tray application techniques on artificial, deciduous enamel carious lesions embedded on wearable appliances. METHODS: In a randomised crossover study, the volunteer children (n = 29) wore mandibular removable appliances containing embedded tooth specimens with artificial carious lesions. The volunteers had 3 different treatment protocols: (I) 0.4 mL non-fluoride (control) gel, (II) 0.4 mL paint-on 1.23% APF gel or (III) 5 mL 1.23% APF gel, 4 minutes tray application. After 1 hour, the appliances were removed and the specimens underwent an in vitro, 14 days of pH-cycling. The mean percentage reduction in fluorescence (ΔF, %) at baseline (ΔF0) and after the pH-cycling (ΔF1) were determined using quantitative light-induced fluorescence-digital analysis. The mean ΔΔF (ΔF1-ΔF0) was calculated to compare the differences between groups. RESULTS: The mean ΔΔF of groups I to III were -1.42 ± 1.49, 1.06 ± 2.11, and 1.12 ± 3.57 and -1.25 ± 1.44, 1.13 ± 1.84 and 1.44 ± 3.62 for the smooth surface and proximal surface lesions, respectively. The mean ΔΔF in the 2 treatment groups were significantly greater compared with the control group (P < .001). There was no significant difference in ΔΔF between the APF gel tray and paint-on groups either in the smooth surfaces, or the proximal surfaces (P = .629 and P = .613, respectively). CONCLUSION: Our study, for the first time, indicates that the paint-on application of APF gel or the tray application of APF had a similar enamel remineralisation effect. Clinically, this implies that, particularly in younger children, the paint-on application of fluoride is less cumbersome, and possibly more tolerable with a lesser likelihood of fluoride ingestion than the tray application technique. TRIAL REGISTRATION: Thai Clinical Trial Registry (https://www.thaiclinicaltrials.org/show/TCTR20190724001).

Red fluorescence of plaque in the dentition-a comparison of Quantitative Light-induced Fluorescence-Digital (QLF-D) images and conventional images of disclosed plaque.

BACKGROUND: Quantitative Light-induced Fluorescence-Digital (QLF-D) detects red fluorescence of plaque, but is almost solely used on labial anterior tooth surfaces. As distribution and formation of plaque varies distinctly within the dentition, our aim was to investigate, how red fluorescing plaque is related to disclosed plaque depending on tooth type and surface. This was done with habitual plaque and after de-novo plaque formation. METHODS: Thirty subjects were enrolled. QLF-Dimages of undisclosed plaque and conventional images of disclosed plaque were planimetrically analysed. Values were expressed as percentage of red fluorescing plaque (P%QLF-D) and of disclosed plaque (P%D) of the total tooth surface. Images were taken at baseline, after de-novo plaque formation (48 (T2) and 72 (T3) h without oral hygiene after professional tooth cleaning), and after 4-6 weeks of habitual oral hygiene (T4). RESULTS: At the tooth level, P%QLF-D was significantly lower than P%D on vestibular surfaces but reached similar levels on oral surfaces. De-novo plaque formation caused a significant increase in P%D on vestibular surfaces; this was not reflected by QLF-D. At the subject level, on vestibular surfaces and at baseline, some subjects exhibited minor but others gross differences between P%QLF-D and P%D. This was not the case at T3, but the same pattern appeared again at T4. On oral surfaces, the order of differences was more evenly scattered with no clear impact of the observation time point. CONCLUSION: Red fluorescence of dental plaque relates very differently to disclosed plaque depending on sites and maturation stages and has a significant inter-individual component.

Comparison of fluorescence parameters between three generations of QLF devices for detecting enamel caries in vitro and on smooth surfaces.

BACKGROUND: This study compared two fluorescence parameters (fluorescence loss [ΔF] and red fluorescence gain [ΔR]) among three generations of quantitative light-induced fluorescence (QLF) systems with the aim of determining the validities of these parameters in the three devices for differentiating the severity of enamel caries. METHODS: Forty-one extracted human premolars and molars with suspected enamel caries were selected. Fluorescence images of all teeth were obtained using first-, second-, and third-generation QLF systems (Inspektor Pro, QLF-D, and Qraycam, respectively). Fluorescence parameters were then calculated using proprietary software. All of the specimens were also categorized histologically using polarized-light microscopy (PLM) based on histological levels related to the lesion depth into sound enamel (S), caries limited to the outer half of the enamel (E1), and caries involving the inner half of the enamel (E2). The Mann-Whitney test with Bonferroni correction was used to compare fluorescence parameters among the three generations of systems. The sensitivity, specificity, and area under the receiver operating characteristics curve (AUC) at two thresholds (S/E1 for detecting enamel caries lesions and E1/E2 for differentiating the caries severity) were calculated for evaluating the validities of the fluorescence parameters obtained using all three generations of QLF devices. RESULTS: ΔF did not differ significantly between the devices at any histological level. In addition, ΔF showed large AUCs at the thresholds of S/E1 and E1/E2 (0.97-0.98 and 0.89-0.90, respectively). On the other hand, ΔR was significantly higher for the third-generation device than for the first- and second-generation devices for E2 lesions (P < 0.001). At the S/E1 threshold, ΔR values of the first- and third-generation devices showed larger AUCs (0.96-0.97) compared with that of the second-generation device (0.91), whereas at the E1/E2 threshold the AUC was the largest for the third-generation device (0.87). CONCLUSIONS: The ΔF fluorescence parameter did not differ between the three generations of QLF devices, and showed high validity values. In terms of ΔR, the devices of all generations also showed good diagnostic performance for quantifying and detecting enamel caries lesions, but the third-generation QLF system produced superior results.

Fluorescence change of Fusobacterium nucleatum due to Porphyromonas gingivalis.

The aim of this study was to measure changes in the fluorescence of Fusobacterium nucleatum interacting with Porphyromonas gingivalis for excitation with blue light at 405-nm. P. gingivalis was mono- and co-cultivated in close proximity with F. nucleatum. The fluorescence of the bacterial colonies was photographed using a QLF-D (Quantitative Light-induced Fluorescence-Digital) Biluminator camera system with a 405 nm light source and a specific filter. The red, green and blue intensities of fluorescence images were analyzed using the image analysis software. A fluorescence spectrometer was used to detect porphyrin synthesized by each bacterium. F. nucleatum, which emitted green fluorescence in single cultures, showed intense red fluorescence when it was grown in close proximity with P. gingivalis. F. nucleatum co-cultivated with P. gingivalis showed the same pattern of fluorescence peaks as for protoporphyrin IX in the red part of the spectrum. We conclude that the green fluorescence of F. nucleatum can change to red fluorescence in the presence of adjacent co-cultured with P. gingivalis, indicating that the fluorescence character of each bacterium might depend on the presence of other bacteria.

Red fluorescence of oral bacteria is affected by blood in the growth medium / 대한구강보건학회지

OBJECTIVES: Dental plaque emits red fluorescence under a visible blue light near the ultra-violet end of the light spectrum. The fluorescence characteristics of each microorganism have been reported in several studies. The aim of this study was to evaluate changes in red fluorescence of oral microorganisms that is affected by blood in the culture media. METHODS: The gram-positive Actinomyces naeslundii (AN, KCTC 5525) and Lactobacillus casei (LC, KCTC 3109) and gram negative Prevotella intermedia (PI, KCTC 3692) that are known to emit red fluorescence were used in this study. Each bacterium was activated in broth and cultivated in different agar media at 37℃ for 7 days. Tryptic soy agar with hemin and vitamin K3 (TSA), TSA with sheep blood (TSAB), basal medium mucin (BMM) medium, and BMM with sheep blood (BMMB) were used in this study. Fluorescence due to bacterial growth was observed under 405-nm wavelength blue light using the quantitative light-induced fluorescence-digital (QLF-D) device. The red, green, and blue fluorescence values of colonies were obtained using image-analysis software and the red to green ratio (R/G value) and red to total RGB ratio (R/RGB value) were calculated for quantitative comparison. RESULTS: The QLF-D images of the AN, LC, and PI colonies showed red fluorescence in all media, but the fluorescence of all bacteria was reduced in TSA and BMM media, compared with in TSAB and BMMB media. Both the R/G and the R/RGB values of all bacteria were significantly reduced in growth media without blood (P<0.001). CONCLUSIONS: Based on this in vitro study, it can be concluded that red fluorescence of oral bacteria can be affected by growth components, especially blood. Blood-containing medium could be a significant factor influencing red fluorescence of oral bacteria. It can be further hypothesized that bleeding in the oral cavity can increase the red fluorescence of dental plaque.

In vitro quantification of occlusal caries lesion using QLF-D, ICDAS, and DIAGNOdent / 대한구강보건학회지

OBJECTIVES: To compare the QLF-D method and the ICDAS and DIAGNOdent techniques for in vitro quantification of occlusal caries and to assess the histological features of the caries. METHODS: One hundred and twenty-two extracted permanent teeth were selected, and the site of interest on the occlusal surface was examined using each detection method. The occlusal sites were classified according to the ICDAS II criteria based on the decision taken by two investigators, who have taken the ICDAS E-learning course. The examined site was then measured using the DIAGNOdent, and the peak value was recorded. In addition, by using the QLF-D, the occlusal site was photographed to obtain the DeltaFmax value. After all assessments were performed, the occlusal sites were vertically sectioned in order to assess the histological features. This was considered the gold standard. The histological criteria were graded using a 4-point scale as follows: S=sound (n=21), E1=limited enamel caries (n=27), E2=caries extending to the dento-enamel junction (n=49), D=caries involving the dentine (n=25). RESULTS: An ICDAS code between 0 and 4 was assigned to all the occlusal sites, and this revealed the QLF-D value, which was between -95 to 0. The DIAGNOdent value was between 8 and 99. The correlation values of QLF-D, ICDAS, and DIAGNOdent with the histological features were 0.68, 0.58, and 0.46, respectively (P<0.01). A highly significant correlation was observed between QLF-D and the gold standard, which showed a moderate correlation and an acceptable correlation was observed with ICDAS (r=0.75, P<0.01). A statistically significant difference was observed in the average QLF-D values of each histological grade i.e., -28.5 (S), -53.7 (E1), -68.1 (E2), and -84.4 (D). CONCLUSIONS: The QLF-D showed a significant correlation with the ICDAS and histological features. Therefore, visual inspection with QLF-D would improve the detection accuracy and ensure early diagnosis of dental caries.