Fibre-optic Transillumination Research Articles

Digital Imaging Fiber-Optic Trans-Illumination, F-speed radiographic film and depth of approximal lesions

Detection of early carious lesions is a prerequisite to an optimal preventive and minimal surgical intervention strategy. The authors conducted this study to determine whether Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI) (Electro-Optical Sciences, Irvington, N.Y.) could be useful in evaluating early approximal lesions and to compare radiographs produced with F-speed film with both histologic lesion depth and cavitation. The authors created artificial approximal lesions in vitro in extracted teeth over 14 weeks and imaged them using a "bitewing-like" view every two weeks with DIFOTI and F-speed radiographic film. At the end of the 14 weeks, the authors examined the lesions for surface cavitation using visual and tactile methods. They then thin-sectioned the lesions and subjected them to histologic analysis using polarized light microscopy (PLM). DIFOTI was not able to measure the depth of a lesion in any of the samples. It was, however, able to show surface changes associated with early demineralization as early as two weeks. The depth of a lesion measured using F-speed radiographic film was not statistically different from the depth of a lesion measured with PLM histologic analysis (P > .05). None of the lesions showed any signs of surface cavitation after 14 weeks of demineralization. DIFOTI technology should not be used to decide between surgical or chemical treatment strategies based on lesion depth. We found that F-speed radiographic film was accurate in the approximating the depth of the lesion histologically. Ideally, the clinical decision whether to cut the tooth should be made based on cavitation rather than histologic lesion depth.

A resource guide for practice development through technology

A resource guide for practice development through technology

Targeted supervised toothbrushing reduces caries increment

Design Randomised Controlled TrialIntervention Supervised toothbrushing on schooldays with 1000 ppm fluoride toothpaste with toothpaste and brushes supplied for home use one class in each school was allocated to intervention and compared to a within-school control over a 2-year period. Dental examinations were performed by a single-blinded examiner at 6-monthly intervals.Outcome measure Visual examinations of caries at D1 level (all visible cavitated and non-cavitated lesions in enamel and dentine). Approximal and occlusal surfaces were also examined using Fibre-optic transillumination (FOTI).Results 86% of those examined at baseline completed study. At baseline children in both groups had similar levels of oral cleanliness; however, children from the more deprived areas had poorer levels of cleanliness. There was no significant difference between the groups in the caries increment in the deciduous teeth after 2 years. Dental immaturity had a significant effect on subsequent caries development. After 2 years there was a significantly less caries in the permanent molars in the intervention group, with 32% fewer D1 lesions (95% CI 4–60%) and 56% fewer D3 lesions (95% CI 13–101%).Conclusions A targeted supervised toothbrushing programme with support for home use resulted in a significant reduction in caries increment.

A systematic review of the performance of methods for identifying carious lesions.

This systematic review evaluates evidence describing histologically validated performance of methods for identifying carious lesions. A search identified 1,407 articles, of which 39 were included that described 126 assessment of visual, visual/tactile, radiographic (film and digital), fiber optic transillumination, electrical conductance, and laser fluorescence methods. A subsequent update added four studies contributing 10 assessments. The strength of the evidence was judged to be poor for all applications, signifying that the available information is insufficient to support generalizable estimates of the sensitivity and specificity of any given application of a diagnostic method. The literature is problematic with respect to complete reporting of methods, variations in histological validation methods, the small number of in vivo studies, selection of teeth, small numbers of examiners, and other factors threatening both internal and external validity. Future research must address these problems as well as expand the range of assessments to include primary teeth and root surfaces.

Reliability of different methods for diagnosis of approximal carious lesions

The aim of this study was to evaluate the diagnosis accuracy of approximal carries by visual, fiber optic transillumination(FOTI) and bitewing radiograph examination performed by two observers.A total of(372) unrestored posterior pertinent approximal surfaces of(186) patients were examined in Conservative Department during final clinical examination for under-graduate students, using the diagnostic methods under the study. The results were compared with the validation.The accuracy of each diagnostic method for identification of cavitated carious lesions was expressed by the terms: sensitivity, specificity and predictive values.The sensitivities for identification of cavitated lesions using visual examination about(0.28), for FOTI and radiography were(0.04) and(0.59) respectively. The specificity collectively was about(0.9).On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. Also, it was found that visual examination should precede theradiographical examination for identification of cavitated carious lesions.

Emerging Methods of Caries Diagnosis

Current diagnostic tools used in dental caries detection are not sensitive enough to diagnose the disease process in its early stages and, frequently, once a diagnosis is made, restoration is the only effective means of treatment. The purpose of this review was to systematically assess the available literature for evidence to determine if emerging diagnostic methods for dental caries are more efficient than traditional methods for detecting and monitoring the progress of caries in permanent and primary teeth. Inclusion and exclusion criteria were established preceding the literature search. Included articles were grouped by type of emerging technology and study design. The types of emerging technologies included laser fluorescence, light fluorescence, digital imaging fiber optic transillumination, and ultrasound. Primarily on the basis of in vitro and preclinical data, some of the reviewed methodologies showed promising results for the detection and monitoring of early caries lesions. However, very little clinical data are available to validate these emerging technologies. It was concluded that, although significant promise is apparent with these technologies, there is not enough evidence available at this time for any of the reviewed diagnostic techniques to be recommended as a substitute for traditional diagnostic techniques.

The use of fibre-optic transillumination in general dental practice

The use of fibre-optic transillumination in general dental practice

A study to assess the use of fibre-optic transillumination in the general dental practice

Objective To assess the use of fibre-optic transillumination (FOTI) as a diagnostic tool in general dental practice. Design A cross-over quantitative study for the diagnosis of approximal carious lesions by two clinical methods with a qualitative component. Subjects and methods Seven GDPs were trained to use FOTI as an adjunct to their usual clinical examination to diagnose approximal caries. After 12 weeks of use in their practices four of the GDPs took part in two assessment sessions, set a week apart, using 29 volunteer patients. Each patient was examined on two separate occasions by each GDP using either their standard clinical examination technique alone or supplemented by FOTI examination. The order of the techniques was randomised. Radiographs of each patient were also examined separately. An experienced FOTI user also examined the patients to provide a benchmark. From standard charts the number of enamel and dentinal lesions on approximal surfaces was summed and comparisons made between the techniques. Six GDPs took part in one-to-one interviews. Main outcome measures Mean numbers of carious lesions recorded by each clinician using each technique. Results There was a trend for all GDPs to find more enamel and dentinal lesions using FOTI, than with their standard clinical examination with or without radiographs. All GDPs found the FOTI technique a useful adjunct. They used FOTI in different ways and found a variety of uses for it other than caries diagnosis. Conclusions The FOTI technique increased the detection of approximal carious lesions. It was reported to be a useful diagnostic tool in general dental practice. GDPs and staff enjoyed participating in a research project.

A study to assess the use of fibre-optic transillumination in the general dental practice

Diagnosis: A study to assess the use of fibre-optic transillumination in the general dental practice

An in vitro Comparison of the Ability of Fibre–Optic Transillumination, Visual Inspection and Radiographs to Detect Occlusal Caries and Evaluate Lesion Depth

The aim of this study was to compare the performance of fibre–optic transillumination (FOTI), visual inspection and bite–wing radiographs to detect occlusal caries and estimate the lesion depth. Fifty–nine extracted molars were assessed using FOTI and visual examination by 4 trained examiners and 1 examiner evaluated the bite–wing radiographs. Histological validation was performed using 250–μm sections examined with a stereomicroscope. For the three methods, the correlation between the lesion depth and the histological scores varied from 0.65 to 0.73. For dentinal caries detection, the areas under ROC curves ranged from 0.83 to 0.87. The radiographic method was poor at detecting lesions confined to enamel. FOTI, visual inspection and radiographs showed a good correlation with the histology but had difficulty in distinguishing lesions located deep in enamel or in the outer third of dentine. FOTI was shown to be as accurate as a detailed visual inspection in detecting occlusal caries.

A Randomised Controlled Trial of the Caries– Preventive Efficacy of a Chlorhexidine–Containing Varnish in High–Caries–Risk Adolescents

A professionally applied two–stage chlorhexidine varnish, Chlorzoin^®, was developed to achieve sustained release and minimise the problems of staining and bad taste associated with chlorhexidine mouthrinses. The primary aim of this randomised controlled clinical trial was to assess the efficacy of Chlorzoin in reducing the caries increment in high–caries–risk adolescents. Secondary aims included investigating the effect of compliance upon caries increment, the effect of Chlorzoin upon salivary mutans streptococci levels and assessing the benefit of individual dental health advice by dental auxiliaries in a community setting. 1,240 children, initially aged 11–13 years, assessed to be at high caries risk were recruited into the trial. The trial design involved four arms: an observational group, a control group, an active (Chlorzoin) varnish group and a placebo varnish group. All subjects were examined annually by a calibrated examiner who was blind to the group allocation. Three–year caries increments were calculated using clinical, clinical and fibre–optic transillumination, and clinical and bitewing data sets. The results indicated that the use of Chlorzoin had an initial effect on mutans streptococci levels but that no long–term reduction in caries increment or mutans streptococci infection could be detected. One reason for this lack of efficacy may have been the regimen of reduced frequency of varnish applications after the initial period. Children who followed the protocol and, therefore, were seen regularly by dental auxiliaries had a lower caries increment than those who did not. This finding was independent of varnish allocation. In summary, under this regimen, Chlorzoin has been found to be effective in decreasing salivary mutans streptococci but ineffective as a caries–preventive agent in high–risk Scottish children when applied pragmatically in a community setting.

Prevalence of Dental Caries in Latvian 11– to 15–Year–Old Children and the Enhanced Diagnostic Yield of Temporary Tooth Separation, FOTI and Electronic Caries Measurement

The aim of this study was to test the feasibility of employing clinical visual examination at the D₁ (enamel and dentine caries) diagnostic threshold, fibre–optic transillumination (FOTI), elective temporary tooth separation (ETTS) and electronic caries measurement (ECM) in the environment of an epidemiological study or clinical trial. It also aimed to compare the diagnostic yield of these diagnostic aides and methods. The sample consisted of 182 Latvian children, mean age 13.3 years (range = 10.6–15.7). For 12–year–old subjects the mean D₃MFS was 10.58 (SD 6.05) and the mean D₁MFS was 19.97 (SD 10.47). The additional diagnostic yield from FOTI examination of approximal sites was 40.0% at the D₁ threshold. The additional apparent yield for ETTS was 52.8% at the D₁ threshold. ETTS detected 38.3% more carious surfaces than FOTI at the D₁ threshold. Conversely 57 surfaces thought to be carious on FOTI examination were judged sound following ETTS. Although the ECM appeared practical to use, it broke early in the trial and the results obtained prior to breakdown appeared inaccurate. In conclusion, all diagnostic methods were feasible under the conditions of an epidemiological study or clinical trial.

DENTAL CARIES DIAGNOSIS

As with any disease process, the early initiation of therapy for dental caries is often the most effective means to ensure resolution. However, for any therapy to be effective, early diagnosis is paramount to success. Unfortunately, current tools used in dental caries detection are not sensitive enough to diagnose the disease process in its early stages and, frequently, once a diagnosis is made restoration is the only effective means of treatment. Quantitative light-induced fluorescence, electrical conductance measurements, direct digital radiography, and direct fiber optic transillumination are methods that may offer promise as effective tools in diagnosing early dental caries. This article describes some of the research that has been performed to make these methods a reality.

Performance of some diagnostic systems in the prediction of occlusal caries in permanent molars in 6- and 11-year-old children

Objectives: Attempts have been made to develop diagnostic methods which enable an early diagnosis of occlusal lesions which are not detectable by visual inspection. The aim of this study was to compare the performance of visual inspection focused on finding signs of fissure decalcification and discoloration, visual inspection upon fibre-optic transillumination (FOTI), and electrical conductance measurements (ECMs) in predicting the onset of occlusal caries in 6- and 11-year-old children. Methods: Fifty children aged 5–7 and 11–15 years, having first or second permanent molar teeth that were not exposed to the oral environment for more than half a year, participated in the study. Following baseline data recording, the diagnostic measurements were repeated six times at 6-month intervals over a period of 2.5 years. Results: Data were collected at predefined sites in the fissures. During the study, 220 of the 652 sites, i.e. 75 of 197 molars in 31 of the 50 children were judged to require a sealant or a sealant restoration. Two examiners jointly decided on the decay status at the sites. Survival plots showed that ECMs were superior to FOTI and fissure discoloration in predicting the onset of occlusal caries, although the differences were small. Conclusion: ECM is a better predictor of occlusal caries than fissure discoloration and FOTI, although the differences among the performance of the three methods in this study were very small. A cost-effective analysis is envisaged to obtain insight into the practical value of ECMs in the prediction of occlusal caries and, thus, into the effectiveness of sealant application.

Reliability of Visual Examination, Fibre-Optic Transillumination, and Bite-Wing Radiography, and Reproducibility of Direct Visual Examination Following Tooth Separation for the Identification of Cavitated Carious Lesions in Contacting Approximal Surfaces

The aim of this study was to evaluate the diagnostic accuracy of visual, fibre-optic transillumination (FOTI), and bite-wing radiographic examination performed by 4 observers for the identification of cavitated carious lesions in contacting approximal surfaces, and to assess the inter-observer agreement with these methods and with direct visual examination conducted after tooth separation, the method used as validation for definitive determination of cavitation. A total of 338 unrestored approximal surfaces in 53 students were examined independently by 4 dentists using the diagnostic methods under study. The results from the diagnostic methods were compared with the results from the validation method for each observer. The sensitivities for identification of cavitated lesions using visual examination ranged from 0.12 to 0.50. For FOTI and radiography, the sensitivities ranged from 0.00 to 0.08 and from 0.56 to 0.69, respectively. The specificities exceeded 0.90 for all observers with all methods. Kappa values expressing inter-observer reproducibility were lowest for FOTI, followed by visual and radiographic examination. On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. For the validation method, the inter-observer agreement was only ‘substantial’. This implies that the method cannot be used as a validation for other diagnostic methods applied for the identification of cavitated carious lesions in contacting approximal surfaces. However, visual inspection after tooth separation may serve as a supplementary diagnostic tool to conventional visual and radiographic examination for clinical management of aproximal carious lesions.

Occlusal caries diagnosis: an in vitro histological validation of the electronic caries monitor (ECM) and other methods

Objectives: The aim of this in vitro study was to validate the use of the Electronic Caries Monitor (ECM) for the detection of enamel and dentinal caries on the occlusal surfaces of posterior teeth, and to compare it with visual examination, fibre-optic transillumination, conventional and digital bitewing radiography. Methods: One-hundred and three extracted posterior permanent teeth with no apparent occlusal cavitation were selected and examined using each system. Thirty teeth were re-examined with each system to assess repeatability. Each tooth was then serially sectioned and examined histologically for occlusal caries. Results: The occlusal surfaces of 25 teeth had caries in enamel and 37 had dentinal carious lesions. The sensitivity and specificity of the ECM were 0.78 and 0.80 for the diagnosis of occlusal dentinal lesions (cut-off=0.391) and 0.65 and 0.73 for enamel lesions (cut-off =0.501). The weighted kappa value for repeatability of the ECM was 0.68. Of the other diagnostic systems, visual examination provided the best combination of sensitivity and specificity, 0.24 and 0.97 for dentinal caries and 0.60 and 0.73 for enamel caries, respectively. Conclusion: The ECM was the most accurate diagnostic tool for the in vitro diagnosis of early, non-cavitated occlusal lesions on posterior teeth.

Occlusal restorative decisions based on visual inspection –calibration and comparison of different methods

The purpose of this in vitro study was to calibrate occlusal restorative decision-making based on visual inspection (VI), and to compare it with visual inspection with magnifying (x1.25) lenses (VIM), and fibre-optic transillumination (VIF). Sixty extracted human third molars mounted in plaster were examined using VI by ten dentists three times during the calibration process. After wash-out periods, the teeth were re-examined by the same dentists using VI, VIM and VIF. The inter-examiner reproducibility for VI, expressed as Kappa (kappa) statistics (kappa +/- SD), was 0.46 +/- 0.10 before and 0.59 +/- 0.11 after the calibration process and remained at the same level after the wash-out period. Intra-examiner reproducibility was substantially higher for VI (kappa -0.68 +/- 0.15) before and after the wash-out period. There were no significant changes in restorative treatment decisions based on VIM and VIF when compared to VI. The reproducibility between the methods was good for VI vs. VIM (kappa = 0.64) and moderate for VI vs. VIF (kappa = 0.56). In contrast, the inter-examiner reproducibilities expressed as Kappa were considerably lower for VIM (kappa = 0.46 +/- 0.17) and VIF (K = 0.42 +/- 0.19). It was concluded that the inter-examiner reproducibility can be improved with a calibration process based on a simple feedback method and that inter-examiner variation, especially without calibration, may be as important a factor for restorative treatment decisions as the diagnostic method itself.

Quantitative diagnosis of small approximal caries lesions utilizing wavelength-dependent fiber-optic transillumination.

The instruments clinically available for the diagnosis of approximal caries lesions are inadequate to detect lesions early and quantitatively. The aim of this study was to investigate whether wavelength-dependent light scattering and absorption of carious tissues may be utilized for the quantitative diagnosis of these small approximal caries lesions. Seventeen extracted premolar teeth were transilluminated at an approximal surface with a glass fiber, which transported the light from a halogen light bulb. Seven approximal surfaces contained a naturally developed small white-spot lesion, and 5 surfaces a small discolored lesion. Five teeth were sound. The occlusal surface was imaged with a CCD camera. Light in the blue and red portions of the electromagnetic spectrum was selected by means of Schott glass filters. From the obtained images, average effective decadic optical thickness differences were determined. These were plotted as a function of average mineral loss assessed by means of wavelength-independent microradiography. The correlation coefficient between the average effective decadic optical thickness difference and average mineral loss was r = 0.79 (95% CI: 0.47 ... 0.93). Different sources of variation that influence the observed correlation were defined and quantified. From these measurements, the correlation coefficient between average effective decadic optical thickness difference and "true' average mineral loss was estimated to be r = 0.92 (95% CI: 0.77 ... 0.97). The results indicate that early and, in principle, also quantitative diagnosis of approximal caries lesions is feasible when wavelength-dependent light propagation through carious tissues is utilized.

Wavelet representations for monitoring changes in teeth imaged with digital imaging fiber-optic transillumination.

Digital imaging fiber-optic transillumination (DI-FOTI) is a novel method to detect and monitor dental caries, using light, a charge-coupled device (CCD) camera, and computer-controlled image acquisition. The advantages of DIFOTI over radiography include: no ionizing radiation, no film, real-time diagnosis, and higher sensitivity in detection of early lesions not apparent to X-ray, as demonstrated in vitro. Here, we present a method of processing DIFOTI images, acquired at different times, for monitoring changes. Of central importance to this application is pattern matching of image frames that is invariant to translation and rotation of a tooth, relative to the field of view of the imaging camera, and that is robust to changes in illumination source intensity. Our method employs: 1) wavelet modulus maxima representations for segmentation of teeth images; 2) first and second moments of gray level representations of DIFOTI images in the spatial domain, to estimate tooth location and orientation; and 3) multiresolution wavelet magnitude representations for quantitative monitoring. Even with illumination source intensity variation, it is demonstrated in vitro that such wavelet representations can facilitate detection of simulated clinical changes in light transmission that cannot be detected in the spatial domain.

Dynamics of and diagnostic methods for detecting small carious lesions.

This paper reviews and discusses the dynamics of carious lesions and diagnostic methods for their detection. Summary data are presented on progression rates of differing lesion types with differing initial severity. Among the non-invasive techniques, fibre-optic transillumination, used appropriately, gives the most accurate estimate of posterior approximal dentinal caries. Electrical resistance methods are likely to provide a significant contribution to the diagnosis of occlusal caries in the future. Radiographs remain an important component of the diagnostic armamentarium and may be enhanced by the introduction of direct digital imaging. Problems in appropriate validation must be addressed to ensure that new techniques are correctly evaluated.