Biomedical subjects

S Tranaeus

Publications and source records attributed to S Tranaeus.

9 recordsLinked to original sources

PubMed2006

A new in vivo method for measuring caries activity using quantitative light-induced fluorescence.

The aim of this in vivo study was to assess the association between caries prevalence and activity parameters and the properties of etched sites measured with quantitative light-induced fluorescence (QLF). In a clinical method, two areas of a deciduous tooth were etched in each of 44 children (mean age 8.23 years+/-1.45) with 36% phosphoric acid gel for 1 min and 4 min, respectively. DeltaQ of the etched site was measured immediately after the etching (DeltaQ1) and 24 h later (DeltaQ2) with QLF. In addition, deft/DMFT, approximal plaque (API), bleeding on probing (mod. PBI), active carious lesions and currently used fluorides were recorded. In a regression analysis for the deft, the use of fluoridated salt (standardized coefficient SC=-0.25) and fluoride gel (SC=-0.37) showed the greatest effect, as did the fluoride gel (SC=-0.26) and gingival bleeding (SC=0.50) for the number of active carious lesions. The deft and the number of active carious lesions correlated significantly (r=0.70, p<0.001). DeltaQ1 and DeltaQ2 showed a significant statistical correlation with the age-adjusted deft (0.39<r<0.52, p<0.01) and with the number of active lesions (0.42<r<0.59, p<0.01). Correlations between DeltaQ and the API, PBI and the fluoride scores were slightly weaker but also statistically significant. In a principal-component analysis, these parameters were approximately identical, indicating a strong relationship between the different variables and DeltaQ. This relationship was especially strong for the deft and the active carious lesion scores. In conclusion, these data suggest that the degree of demineralization by etching and its changes with time are associated with caries activity and that this method might be used for the early assessment of caries activity.

Child↗

PubMed2006

DIAGNOdent--an adjunctive diagnostic method for caries diagnosis in epidemiology.

UNLABELLED: The DIAGNOdent system is intended as an aid to caries detection and has undergone extensive investigation in experimental and clinical studies. Its applicability for epidemiological purposes has yet to be evaluated. The Objective of the present study was to evaluate the DIAGNOdent system under field conditions. BASIC RESEARCH DESIGN: The subjects comprised a sub-sample from an on-going epidemiological study. PARTICIPANTS AND CLINICAL SETTING: In 39 individuals, 97 sites were visually identified as possibly carious: 42 occlusal, 13 lingual, 19 buccal and 23 approximal sites. MAIN OUTCOME MEASURES: Three DIAGNOdent measurements were taken at each site under varying conditions: (1) naturally wet, (2) dried, and (3) polished and dried surfaces. Three sets of measurements were obtained and compared by intra-class correlation and paired sample t-tests. RESULTS: All correlation coefficients were > 0.9. There was a systematic difference between mean scores from naturally wet sites (without cleaning) and from either dried, or polished and dried sites. The difference was marginal and did not impact on the threshold for recording sites as carious. In two subjects, high unexpected values were recorded on sound sites prior to actual measurements, i.e. during establishment of a standard value for a sound site. The overall findings were not affected by these values, as they were consistently high in all three measurements. CONCLUSIONS: The DIAGNOdent system performed satisfactorily under different measurement conditions. The present study indicates that the DIAGNOdent system would be applicable in field studies, provided consistent study conditions are maintained and unexpected values are interpreted with caution.

Adult↗

PubMed2001

Application of quantitative light-induced fluorescence to monitor incipient lesions in caries-active children. A comparative study of remineralisation by fluoride varnish and professional cleaning.

The aim of this study was to apply the quantitative light-induced fluorescence (QLF) method in a randomised controlled study, comparing treatment with fluoride varnish and professional tooth cleaning for remineralisation of white spot lesions in caries-active adolescents. In the fluoride varnish group (n = 13; 32 lesions), professional tooth-cleaning was followed by application of fluoride varnish at the beginning of the study, after 1 wk, and then once every 6 wk for 6 months. The other group (n = 18; 30 lesions) underwent professional tooth-cleaning once every 6 wk for 6 months. Enamel fluorescence was measured at baseline and at each visit. In the fluoride varnish group there was a significant change over time (baseline: 6 months) for both lesion area: and average change in fluorescence (decreased lesion area and increased fluorescence radiance). The corresponding changes in the professional tooth-cleaning group were not significant. There was a significant difference in average change in fluorescence between the two test groups. For lesion area, there was no significant difference, but a tendency towards a difference between the test groups. It was concluded that (a) the QLF method is a sensitive method, suitable for longitudinal quantification of incipient caries lesions on smooth surfaces; and (b) that repeated fluoride applications had a favourable effect on the remineralisation of white spot lesions as measured after 6 months.

Adolescent↗

PubMed2001

Validation of DIAGNOdent for quantification of smooth-surface caries: an in vitro study.

The aims were 1) to validate a laser-based device, KaVo DIAGNOdent, for quantification of caries lesions on smooth surfaces, using histopathologic and microradiographic analyses as the gold standard, and 2) to test inter- and intra-observer agreements. We also investigated the influence on DIAGNOdent readings of the storage medium used for extracted teeth. Two observers measured independently the tooth surfaces of 40 extracted premolars that had been stored in thymol-saturated saline. After subsequent storage in neutral-buffered formalin for 14 days they were re-measured. The teeth were then sectioned for histopathologic and microradiographic analysis. The Spearman rank correlation coefficients between lesion depth and DIAGNOdent readings were 0.78-0.83 and 0.85 for teeth stored in thymol-saturated saline and formalin, respectively. Inter- and intra-observer agreements were 0.94 and 0.95 when the teeth were stored in thymol-saturated saline. The DIAGNOdent reading was almost 1.5 times higher for teeth stored in formalin than for those stored in thymol saline. The Spearman rank correlation coefficient between mineral loss in enamel (deltaZ) and DIAGNOdent readings ranged from 0.64 to 0.68. It was concluded that DIAGNOdent may be helpful for assessing smooth-surface caries, but the cut-off points need to be assessed under clinical conditions. The increase in fluorescence associated with storage of teeth in formalin warrants further investigation.

Analysis of Variance↗

PubMed1998

Caries diagnosis.

Explore the source record for details and available documents.

Dental Caries↗

PubMed1997

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.

Dental Caries↗

PubMed1996

Monitoring the caries process. Optical methods for clinical diagnosis and quantification of enamel caries.

Early detection of a caries lesion would enable the dentist, by using effective prophylactic measures, to enhance remineralization and conservation of the tooth substance rather than restoration of the dentition. The presently-used diagnostic methods of detecting early lesions require visual observation. Reflected light is used to detect changes in color, texture, and translucency of the tooth substance. Attempts to improve the traditional methods or to develop new ones have been numerous. For clinical use, only 2 quantitative methods are presently available: (i) a method based on the scattering of light by enamel crystals in relation to their surrounding environment, and (ii) a method that uses visible laser light within the blue-green region as the light source to excite the autofluorescence of enamel. The possibilities and limitations of these methods are evaluated, and clinical applications are presented and discussed.

Color↗

PubMed1995

A new method for in vivo quantification of changes in initial enamel caries with laser fluorescence.

A new method for the in vivo assessment of changes in initial enamel caries lesions was developed and tested. A CCD camera equipped with a high-pass filter (lambda > 520 nm) collects the fluorescence image of carious teeth, illuminated intraorally with diffuse laser light (lambda = 488 nm). Incipient lesions show a loss in fluorescence to be expressed as a percentage of fluorescence radiance of sound tissue. A PC program (Inspektor, model QLF 1.0) is used for display, storage, and subsequent analysis of images. To enable the calculation of fluorescence loss, the fluorescence of sound tissue at the lesion site is reconstructed from the radiances of sound tissue bordering the lesion. This method was tested on 19 visually sound buccal surfaces in vivo. The differences between actual and reconstructed radiance was -1.6 +/- (SD) 1.1%, over areas varying between 8 and 14 mm2. The repeatability of the caries quantification was tested by measuring one arrested initial caries lesion 25 times in vivo. The lesion area was 0.56 +/- 0.20 mm2, and the loss of fluorescence was 17.6 +/- 0.7%, corresponding to a lesion depth of 17 +/- 2 microns. The new quantitative method was applied for the testing of an in vivo caries model using plaque-accumulating brackets on premolars scheduled for extraction. Videoimages were recorded in vivo before bracketing and 0, 2, 3, and 5 weeks after debracketing. Clear changes between the different time points were recorded for both lesion size and mineral content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Comparison of QLF and DIAGNOdent for quantification of smooth surface caries.

The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light-induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non-cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five-point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman's rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D(3) level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut-off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut-off value of 20% of fluorescence loss. Spearman's rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

Adolescent↗