Biomedical subjects

Lutz Stösser

Publications and source records attributed to Lutz Stösser.

6 recordsLinked to original sources

PubMed2006

Establishing quantitative light-induced fluorescence cut-offs for the detection of occlusal dentine lesions.

The aims of this in vitro study were, first, to define suitable cut-off values for the detection of occlusal dentine lesions by means of quantitative light-induced fluorescence (QLF), and, second, to compare the validity of light microscopy (LM) and microradiography (MR) as reference standards. Fifty-four third molar occlusal fissures with sound sites or non-cavitated lesions were examined. Standard QLF equipment was used to capture, display, store, and analyze fluorescence images. Each tooth was cut into sections in the bucco-lingual direction using a microtome saw, and the caries levels were subsequently assessed with the two reference methods. The histological examination with LM indicated that 46% of the specimens had carious lesions progressing into the dentine compared with 41% measured using MR (D3-4 level). Using optimal cut-off levels for the detection of dentine lesions, the sensitivity and specificity values were > 80%. The area under the receiver operating characteristic curve was slightly higher for MR (0.91-0.93) than for LM (0.88-0.89). The results of this study give a good idea of suitable cut-off points for the detection of occlusal dentine lesions using QLF. Owing to the small number of specimens in this study, further studies should be carried out before establishing definite cut-offs.

Area Under Curve↗

PubMed2005

Detection of initial caries lesions on smooth surfaces by quantitative light-induced fluorescence and visual examination: an in vivo comparison.

The aim of this clinical study was to compare the outcome of quantitative laser/light-induced fluorescence (QLF) and visual inspection (VI) for the detection of initial caries lesions on all maxillary and mandibular smooth surfaces in caries-risk adolescents. The subjects were 34 students, mean age 15 yr. A total of 879 buccal and 882 lingual surfaces were air-dried and visually examined at a magnification of x3.5. Fluorescence images of each smooth surface were captured with QLF\clin equipment, and QLF software 2.00 was used to display, store, and analyse the images. Fluorescence loss (deltaF; %) and area of the lesion (A; mm2), and fluorescence loss integrated over the lesion area (deltaQ; deltaF x A; % x mm2), were determined. The presence or absence of initial caries lesions was scored using both VI and QLF. A total of 87.2% of all smooth surfaces were scored as sound or initially carious when assessed by VI + QLF in combination: 4.9% were detected by VI alone and 7.9% by QLF alone. The parameters DeltaF, A, and DeltaQ differed significantly between lesions registered with VI + QLF and QLF alone. It was concluded that (i) QLF seems to be a sensitive method that is suitable for the detection of visually undetected initial caries lesions; and (ii) that the clinical use of QLF is limited by several confounding factors in caries-risk adolescents.

Adolescent↗

PubMed2004

Assessment of enamel erosion and protective effect of salivary pellicle by surface roughness analysis and scanning electron microscopy.

PURPOSE: To assess dental erosion caused by 0.1% and 1.0% citric acid in vitro and to estimate the protective influence of experimentally formed salivary pellicle. MATERIALS AND METHODS: Bovine enamel slabs (n = 80) were polished and embedded in epoxy resin. For the formation of pellicle layer 40 specimens were immersed for 24 h in pooled human saliva. Erosion was caused by immersion in citric acid solution for 1, 5, 10 and 30 min. Erosive alterations on the pellicle-covered and non-covered enamel specimens were scored as a change (delta) of surface roughness parameters Ra, Rt and RzDIN using contact profilometer and observed in scanning electron microscope. RESULTS: Profilometric analysis of eroded enamel specimens emphasized the aggressiveness of even low concentrated citric acid with a short period of challenge. The change of roughness parameters after 1-min immersion in 0.1% citric acid were 16.4, 182.6 and 132.2 nm for deltaRa, deltaRt and deltaRzDIN, respectively, and 54.8, 516.6 and 258.2 nm after 1-min immersion in 1.0% citric acid. Changes of the surface roughness were dependent on the exposure time and concentration of acidic solution. Pellicle layer significantly reduced the extent of erosive destruction, which was additionally documented on SEM-micrographs. Residual pellicle-like structures were detected after 5 min of immersion in 0.1% citric acid. However, there were no significant differences in pellicle-covered and non-covered enamel slabs measured profilometrically for 1.0% citric acid with 10 min and 30 min exposure time. CONCLUSION: The findings confirm the property of pellicle layer to resist against erosive influence of organic acids, which is, however, limited by duration of acidic treatment and concentration of erosive agent.

Animals↗

PubMed2003

Quantitative light-induced fluorescence (QLF)--a potential method for the dental practitioner.

The quantitative light-induced fluorescence (QLF) method is based on the natural fluorescence of teeth. Currently, the method is predominantly used in vitro and in clinical studies for early detection of carious lesions and for monitoring of de- and remineralization of white spots by quantifying the mineral loss and the size of smooth surface lesions. The objective of this paper was to demonstrate the potential of QLF for application in routine dental care. Experience with QLF was reported by selected cases, which enlightened the advantages of the method for caries detection and for evaluation of preventive interventions in caries-prone patients in daily practice.

Dental Caries↗

PubMedDate not supplied

Protective influence of experimentally formed salivary pellicle on enamel erosion. An in vitro study.

The purpose of this study was to evaluate dental erosion in 0.1 and 1.0% citric acid in vitro by several different methods and to assess the protective potential of experimentally formed salivary pellicle (24 h in vitro). Bovine enamel slabs were embedded in epoxy resin and polished. Erosion was performed in citric acid for 1, 5 or 10 min and recorded as microhardness loss, as changes of surface roughness (R(a), R(t) and R(zDIN)) and as calcium release. Additionally, erosive alterations were observed with scanning electron microscopy. Significant microhardness loss on non-pellicle-covered specimens was measured after 1-min exposure to 0.1% citric acid. Microhardness loss was time- and concentration-dependent. Salivary pellicle significantly inhibited both microhardness loss, except after 10-min immersion in 1.0% citric acid, and significantly reduced the increase of surface roughness. There were, however, no significant differences in calcium release between pellicle-covered and non-covered enamel. The results support the general conclusion that salivary pellicle effectively protects enamel surface against short-term erosion in organic acids.

Analysis of Variance↗

PubMedDate not supplied

Clinical evaluation of visual, radiographic, and laser fluorescence methods for detection of occlusal caries.

The aim of this clinical study was to test cut-offs for occlusal caries detection by the laser fluorescence device DIAGNOdent (DD) in comparison to visual-ranked inspection (VI) and bitewing radiographs (BW) under condition of a general dental practice. 281 occlusal surfaces of permanent molars from 97 patients were examined with VI, DD and BW. Caries extent was verified by bioptical intervention (gold standard) of 248 molars. Upon biopsy no molar was assessed as caries free, 24 teeth had caries confined to enamel and 224 teeth revealed dentine caries. For dentine caries detection DD achieved the highest values for sensitivity (0.93), specificity (0.63) and agreement (0.89) followed by BW with figures of 0.70, 0.96 and 0.69, respectively. VI exhibited the lowest sensitivity (0.25) and agreement (0.25), but the highest specificity (1.00). It is advised to assess occlusal surfaces by a meticulous VI followed by the use of DD and/or BW as additional diagnostic tool of second choice. A DD value of > 20 could be confirmed as a sensitive cut-off for detection of occlusal dentine caries in first and second permanent molars. For the detection of early signs of enamel caries the DD seems to be less suitable.

Adolescent↗