Demineralization Depth Using QLF and a Novel Image Processing Software

Effects of toothpastes on white spot lesions around orthodontic brackets using quantitative light-induced fluorescence (QLF) : An in vitro study

AIM

The aim of this study was to investigate the effects of toothpastes with different contents on the remineralization of white spot lesions around orthodontic brackets by quantitative light-induced fluorescence (QLF).

MATERIALS AND METHODS

A total of 45 freshly extracted human mandibular first molars were selected. Artificial caries lesions were created on enamel surfaces using an acidified gel system for 7 days. Initial relative fluorescence loss was calculated as the pretreatment (baseline) fluorescence value by QLF device. Molar tubes were bonded using light-cured resin composite cement. The specimens were randomly divided into three experimental groups (n = 15). Different toothpastes were applied to demineralized enamel: (1) fluoride-containing toothpaste (Colgate Total^®), (2) Novamin-containing toothpaste (Sensodyne^® Repair and Protect), (3) probiotic-containing toothpaste (GD Probiotic Toothpaste^®). After 2 weeks of treatment, fluorescence loss and lesion area were measured with QLF. To determine fluorescence changes, intergroup comparisons were performed with a multivariate analysis of variance, followed by Tukey's test at a probability value of p < 0.05.

RESULTS

Significant differences were observed between initial and posttreatment QLF measurements of the demineralized enamel specimens treated with the various agents (p < 0.05). In all experimental groups, significant fluorescence radiance increase and decrease of the lesion area (p = 0.000) was found.

CONCLUSION

Novamin-containing toothpaste provided more increase of fluorescence compared to fluoride- and probiotic-containing toothpastes.

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.

Diagnosis of occlusal caries lesions in deciduous molars by coherent light scattering pattern speckle

BACKGROUND

This study presents the correlation between laser speckle images and detection of incipient caries lesions from changs in the microstructure of the surface of tooth enamel.

METHODS

We used 30 healthy deciduous molar teeth collected from the Biobank Human Teeth, Faculty of Dentistry, University of São Paulo who had carious lesions induced by the pH cycling method. The samples were evaluated for the diagnosis of caries by two methods ICDAS and speckle pattern of coherent light scattering after 5, 10 and 15days and the results were statistically analyzed using α=0.05 significance level.

RESULTS

A significant difference was observed between the image of the speckle scattering of healthy and injured areas within the 3 study groups, but not when comparing the three groups, showing us that it is an innovative technique that needs further study, but can be used as a diagnostic method for the detection of early caries lesions.

CONCLUSION

It can be concluded that the analysis of scattering speckle pattern is a diagnostic technique that provides information on the microstructure of the surface of tooth enamel which has sensitivity for detection of incipient caries lesions.

Application of quantitative light-induced fluorescence to determine the depth of demineralization of dental fluorosis in enamel microabrasion: a case report

Enamel microabrasion has become accepted as a conservative, nonrestorative method of removing intrinsic and superficial dysmineralization defects from dental fluorosis, restoring esthetics with minimal loss of enamel. However, it can be difficult to determine if restoration is necessary in dental fluorosis, because the lesion depth is often not easily recognized. This case report presents a method for analysis of enamel hypoplasia that uses quantitative light-induced fluorescence (QLF) followed by a combination of enamel microabrasion with carbamide peroxide home bleaching. We describe the utility of QLF when selecting a conservative treatment plan and confirming treatment efficacy. In this case, the treatment plan was based on QLF analysis, and the selected combination treatment of microabrasion and bleaching had good results.

Efficacy of different strategies in protecting enamel against demineralization during fixed orthodontic treatment

BACKGROUND AND OBJECTIVE

Sealant application is a common strategy for preventing enamel demineralization during multibracket treatment. The aim of this study was to assess the efficacy in enamel demineralization prevention of two fluoride-containing enamel varnishes compared to a non-fluoride varnish, weekly fluoride gel application, and a non-treated control group.

MATERIALS AND METHODS

Enamel specimens obtained from 75 human upper permanent incisors were randomly allocated to five trial groups (each n = 15): A), ProSeal (Reliance), B), Maximum Cure® (Reliance), C), CervitecPlus (Ivoclar Vivadent, Schaan, Liechtenstein), D) elmex® gelée (GABA, Lörrach, Germany), and E), a non-treated control group. Groups A-C received a baseline varnish application, whereas group D specimens received a once weekly gel application for 2 min. Six demineralization cycles per day were carried out for 5 min each using 0.05 M citric acid, with the specimens stored in remineralization solution between cycles. Lesion depth expressed in percentage fluorescence loss (Δ-F in %) compared to baseline (T0) was assessed quantitatively with light-induced fluorescence (QLF) after 3 (T1), 7 (T2), 14 (T3), and 30 (T4) days globally and for each time point, and analyzed for compounds using the Kruskal-Wallis test (α = 5%), and additional one-sample Wilcoxon tests for each time/compound combination (Bonferroni-corrected α-levels α* = 0.05/4 = 0.0125).

RESULTS

Significant fluorescence loss revealing greater lesion depth was detected in the untreated controls (E) at T3, and in groups A (ProSeal) and C (CervitecPlus) at T4. No significant Δ-F changes were seen in the specimens from groups B (Maximum Cure®) and D (elmex® gelée).

CONCLUSION

Maximum Cure® sealant seems to offer efficient protection against demineralization during fixed orthodontic treatment, as does weekly application of elmex® fluoride gel.