|Year : 2017 | Volume
| Issue : 1 | Page : 2-6
In vitro study to evaluate laser fluorescence device for monitoring the effect of aluminum gallium arsenide laser on noncavitated enamel lesions
Sonali Sharma1, Mithra N Hegde2, Vandana Sadananda3, Blessen Matthews3
1 Command Military Dental Centre, Western Command, Chandimandir, Haryana, India
2 Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, A B Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore, Karnataka, India
3 Department of Conservative Dentistry and Endodontics, A B Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore, Karnataka, India
|Date of Web Publication||23-Jun-2017|
482, Pocket E, Mayur Vihar Phase II, New Delhi - 110 091
Source of Support: None, Conflict of Interest: None
Objective: The objective of this study was to evaluate the efficacy of laser fluorescence (LF)-based diagnostic device for monitoring the effect of aluminum gallium arsenide (Al Ga As) laser on noncavitated enamel lesions. Background: Dental caries is a reversible disease, and scope of reversing the carious lesion is increased if it is diagnosed before there is surface cavitation. Variegated remineralization strategies including remineralizing pastes and different lasers have been explored. The efficacy of this surface treatment requires a valid and a reliable assessment tool. LF is one such adjunct to traditional methods of caries detection. Materials and Methods: Twenty-five intact freshly extracted molars were sectioned mesiodistally so as to obtain fifty samples which were coated with nail varnish so that 3 mm × 3 mm of windows are created to maintain uniformity. All sample surfaces were evaluated with LF device so as to obtain the baseline values, these values served as control. All the samples were then acid etched by 30% phosphoric acid for 20 s to simulate surface demineralization. The LF device was used to record the values of demineralized samples. The surfaces of the teeth were then irradiated with Al Ga As laser of 3.5 W for 30 s. The LF device was then used to record the reading. Statistical Analysis Used: Statistical analysis was done using paired t-test to compare control and test groups and calculation of the mean. Results: The demineralized surfaces have recorded statistically significant LF values greater than the untreated control sample values. Post laser irradiation, there is fall of the LF values and these values are closer to that of control. Conclusion: Laser fluorescence can be used as a tool to detect demineralization in situ and monitor changes in enamel surface during demineralization and remineralization phases. Surface treatment with laser irradiation gave values closer to that of control and this does indicate that laser irradiation brings about surface alteration as evaluated by laser fluorescence.
Keywords: Aluminum gallium arsenide laser, dental caries, laser fluorescence, noncavitated lesions
|How to cite this article:|
Sharma S, Hegde MN, Sadananda V, Matthews B. In vitro study to evaluate laser fluorescence device for monitoring the effect of aluminum gallium arsenide laser on noncavitated enamel lesions. J Dent Lasers 2017;11:2-6
|How to cite this URL:|
Sharma S, Hegde MN, Sadananda V, Matthews B. In vitro study to evaluate laser fluorescence device for monitoring the effect of aluminum gallium arsenide laser on noncavitated enamel lesions. J Dent Lasers [serial online] 2017 [cited 2017 Aug 17];11:2-6. Available from: http://www.jdentlasers.org/text.asp?2017/11/1/2/208943
| Introduction|| |
Dental caries is a dynamic, progressive, multifactorial disease with varying phases of demineralization and remineralization. The scope of reversing the carious lesion is increased if it is diagnosed before there is surface cavitation. The current methods of diagnosing caries are not reliable and reproducible. Nearly 30%–40% of mineral loss takes place before any carious lesion can be detected on radiograph. To harness the remineralization potentiality of an incipient lesion, it becomes imperative that these lesions are timely detected, diagnosed, and periodically assessed for lesion activity. A diagnostic aid or device which is valid, reliable, and whose results can be quantified and are reproducible is the need of the hour.,,
The importance of diagnosing noncavitated lesion has been understood since 1900, but since the last two decades, the cariology research has got the much-needed impetus. The most common traditional method of caries detection is visual-tactile and radiography. The accuracy of visual-tactile method in caries detection of noncavitated, incipient lesion, or hidden caries when used alone, depends on the clinical acumen and optical acuity of the operator and also the protocol followed such as drying tooth surface, removal of biofilm, separation of the teeth for detecting proximal caries, good lighting, and the probes used. Thus, visual-tactile method for both lesion detection and lesion assessment may not be a valid and reliable diagnostic test, especially when used alone.,,,
Radiographic method can be used as a baseline diagnostic tool, estimating the depth of lesion and for assessing and monitoring progression of lesion over a period of time, and it is a more sensitive tool than clinical inspection. However, since caries detection on radiographs depends on mineral loss, the lesion may have progressed beyond the scope of remineralization before it is detected. Moreover, radiography cannot distinguish between active and arrested lesions, and diagnosis is dependent on the interpretation skill of the dentist.,,,,,
Noninvasive techniques for detection of early caries have been developed and investigated such as quantitative light-induced fluorescence, DIAGNOdent (DD), fiber-optic transillumination, and electrical conductance.,, One such caries detection method based on laser-induced fluorescence, which is noninvasive and quantitative in nature, is laser fluorescence (LF) device (DIAGNOdent pen 2190 KaVo, Biberach, Germany). This device, as an adjunct to traditional method, has shown good results in the detection of occlusal caries.,, Hence, this study was carried out to assess the efficacy of LF-based diagnostic device for detecting noncavitated lesions and monitoring the effect of aluminum gallium arsenide (Al Ga As) lasers on such lesions and to explore its viability as an accepted diagnostic aid in preventive and interceptive regimen of dental caries in routine dental practice.
| Materials and Methods|| |
- LF device (DIAGNOdent pen 2190 KaVo, Biberach, Germany)
- Al Ga As Laser (Whitestar™, Creation, Verona, Italy)
- 37% phosphoric acid gel (Total Etch™ – Ivoclar Vivadent AG, Schaan/Liechtenstein).
This study aims at evaluating the effectiveness of laser fluorescence in detecting any changes in the surface of enamel by demineralization and remineralization. Twenty-five intact freshly extracted molars were sectioned mesiodistally so as to obtain fifty samples which were coated with nail varnish so that 3 mm × 3 mm of windows are created to maintain uniformity. All sample surfaces were evaluated with LF device so as to obtain the baseline values, these values served as control. All the samples were then acid etched by 30% phosphoric acid for 20 s to simulate surface demineralization. The LF device was used to record the values of demineralized samples. The surfaces of the teeth were then irradiated with Al Ga As laser of 3.5 W for 30 s. The LF device was then used to record the reading. The results were tabulated and computed. Statistical analysis was done using paired t-test to compare control and test groups and calculation of the mean.
| Results|| |
[Table 1]: It is observed that the demineralized samples laser fluorescence values are higher than that of control and these values are statistically significant. Post laser irradiation it was observed that the laser fluorescence values fall and are closer to that of control. Demineralized samples have highest difference with control; it has significantly higher value than laser irradiated treatment samples also.
[Table 2]: Laser fluorescence values show that there is statistical significant difference between control and demineralized samples. It is observed that the values after surface treatment with laser irradiation are closer to control. Demineralized samples have highest difference with control; it has significantly higher value than treatment samples also.
Graph 1: There is significant difference between means of control and demineralized samples and treated and demineralized samples. The treated samples have laser fluorescence values closer to that of control.
Graph 2: The laser fluorescence device's values of the treated samples are closer to that of control as compared with demineralization
| Discussion|| |
Evidence-based studies have shown that visual examination in caries diagnosis has a high specificity but low sensitivity and reproducibility and it should be used in conjunction with other methods., Radiographs have high specificity and low sensitivity for caries detection, thus the chances of false-negative results is more than false-positive results., Though the traditional methods are routinely used in caries detection, changing patterns of the lesions' behavior and the scope of reversing the carious lesion make it mandatory to detect and diagnose early incipient lesions.,,,,
There is a plethora of newer devices flooding the market based on the principles of optical properties, sound, LF, and electric conductance in carious dentin. Benedict as early as 1928 had postulated that light absorption and reflection in enamel, dentin, and cementum are different and more so ever in healthy and carious enamel and dentin. The autofluorescence of dental tissues and bacterial porphyrins of carious lesions can be quantified by lasers. The first LF device, DIAGNOdent (KaVo, Biberach, Germany), was developed in 1998. It is based on the quantification of autofluorescence emitted from organic components of dental tissues when irradiated by a 655 nm diode laser.
Studies by Lussi et al., Novaes et al., Attrill and Ashley, Fung et al., and Burin et al. have all inferred that LF method is a predictive diagnostic tool and is more sensitive than the traditional method of visual and radiographic examination, and most studies have recommended it as adjunct in the diagnosis of carious lesions.,,,, Moriyama et al. in an in vitro study evaluated the effectiveness of fluorescence-based methods to detect in situ demineralization and remineralization on smooth surfaces and they concluded that it was an effective assessment in smooth surfaces. Hence, in this study, LF was selected as an assessment tool to study the effect of Al Ga As laser on demineralized surface.
Remineralizing strategies over a period of time have ranged from incorporating fluorides alone or in combination with remineralizing pastes such as casein phosphopeptide with amorphous calcium phosphate.,,, Since lasers were introduced in dentistry, they have been experimented in caries inhibition with varying success.,,,,, Currently, Al Ga As laser is being evaluated as a preventive and interceptive caries inhibitory tool. It is hypothesized that the greater selectivity of these wavelengths in targeting and removal of the carbonate group from the enamel mineral molecule results in greatly increased acid-resistant enamel., Hence, in this study, we have irradiated the surface of demineralized tooth with Al Ga As laser. Results have shown that, when the samples were demineralized, the LF values increased in the controls which were intact tooth samples. Thereafter, when the demineralized tooth surfaces were irradiated with 3.5 W of Al Ga As laser, and subsequently evaluated, the LF values decreased and was closer to that of control [Table 1], [Table 2] and [Graph 1], [Graph 2].
| Conclusion|| |
- LF device has been able to read out minimal surface demineralization and also the surface changes after laser irradiation protocol. Thus, LF can be used as a tool to detect demineralization in situ and monitor changes in enamel surface during demineralization and remineralization phases
- Surface treatment with laser irradiation gives LF values closer to that of control and this does indicate that laser irradiation brings about surface alteration as evaluated by LF. As a corollary, it follows that laser irradiation does bring about alteration in the surface or subsurface layers of enamel. This hypothesis needs to be corroborated with further surface analysis studies of enamel when irradiated with Al Ga As laser.
We acknowledge the contribution of Mr. SS Tanwar for statistical analysis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]