Vitus Stachniss

Reproducibility and Accuracy of the ICDAS-II for Detection of Occlusal Caries in vitro

Aim: The aim of this study was to assess inter- and intra-examiner reproducibility and accuracy in the detection and assessment of occlusal caries in extracted human teeth using a newly developed visual method for caries diagnosis (International Caries Detection and Assessment System, ICDAS-II). Serial sectioning and microscopy were used as the ‘gold standard’. Methods: The occlusal surfaces of 100 teeth were examined by 4 dentists using the ICDAS-II graded scores 0–6. Thereafter the teeth were serially sectioned and assessed for depth of the lesion with two histological classification systems. Results: The weighted kappa values for inter- and intra-examiner reproducibility for the ICDAS-II examination were 0.62–0.83. There was a moderate relationship between the visual and both histological examinations (rs = 0.43–0.72). At the D1 diagnostic threshold (enamel and dentine lesions) specificity was 0.74–0.91 and sensitivity was 0.59–0.73. At the D3 diagnostic threshold (dentine lesions) specificity was 0.82–0.94 and sensitivity was 0.48–0.83 for the 4 examiners. Conclusion: The ICDAS-II system has demonstrated reproducibility and diagnostic accuracy for the detection of occlusal caries at varying stages of the disease process which are comparable to previously reported data using similar visual classification systems.

Longevity of cast gold inlays and partial crowns--a retrospective study at a dental school clinic.

Abstract From 1963 to 1993, 890 patients were treated with 3518 cast gold restorations by students and postgraduate dentists. The longevity of these restorations was studied retrospectively using the patient files. Longevity was calculated using the method described by Kaplan and Meier. After the observation period, 111 (3.2%) of the examined restorations were not in place anymore. The most frequent reasons for failure were caries (33.7%), lack of retention (32.7%), endodontic treatment (29.6%), insufficient marginal adaptation (3.1%) and extraction (1%). The cumulative survival rate and a 95% interval of confidence was calculated for all restorations and for each of the locations and surfaces included in the trial. The 10-year survival rate for occlusal inlays was, 76.1% (12.1) for MO inlays 88.3% (4.2), for DO inlays 83.4% (4.6), for MOD inlays 87.5% (2.4), for partial crowns 86.1% (3.3) and 85.7% (1.7) for all restorations. Based on the statistical method used, the cast gold restorations demonstrated satisfactory longevity results.

Performance of laser fluorescence at tooth surface and histological section

This study aimed to evaluate a laser fluorescence device (the DIAGNOdent) and a visual classification system (ICDAS-II) for occlusal caries diagnosis. It also aimed to determine whether fluorescence measurements taken at the tooth surface correlate with the fluorescence measurements taken within the body of the lesion. The occlusal surfaces of 100 extracted permanent teeth were examined using ICDAS-II and DIAGNOdent (LF-tooth). Serial sections were made and lesion depth was assessed histologically. DIAGNOdent readings were also taken from the sections (LF-section). There were significant positive strong correlations between ICDAS-II and histology (rS = 0.71) and LF-section and histology (rS = 0.70), and only moderate correlations between LF-tooth and histology (rS = 0.51) and LF-tooth and LF-section (rS = 0.60). Diagnostic accuracy for ICDAS-II was generally better than for LF-tooth. While the DIAGNOdent device provides an objective reading for detection and monitoring of carious lesions, using the cut-off ranges previously suggested leads to inferior performance.

Performance of a fluorescence camera for detection of occlusal caries in vitro.

The aim of this study was to assess inter- and intra-examiner reproducibility and accuracy in the detection and assessment of occlusal caries in extracted human teeth using the newly developed fluorescence based camera VistaProof. Serial sectioning and microscopy are considered the gold standard. The occlusal surfaces of 53 teeth (99 investigation sites) were examined by two examiners with different levels of experience in cariology (one experienced dentist, one final-year dental student) and the VistaProof. Thereafter, the teeth were serially sectioned and assessed for lesion depth. The intraclass correlation coefficients for inter- and intra-examiner reproducibility for the fluorescence-based examinations were 0.76–0.95. There was a significant correlation between the fluorescence and histological examinations for both examiners (rs = 0.47 and 0.55, P < 0.01). At the D1 diagnostic threshold (enamel and dentin lesions), sensitivity was 0.71–0.86 and specificity was between 0.32 and 0.76 at different cutoff values. At the D3 diagnostic threshold (dentin lesions), sensitivity was 0.04–0.91 and specificity was 0.56–0.99 for both examiners. When the areas under the receiver-operating characteristic curves were compared, there was no significant difference in the performance between the examiners (P = 0.52 at the D1 threshold, P = 0.81 at the D3 threshold). The VistaProof demonstrated high reproducibility and good diagnostic performance for the detection of occlusal caries at various stages of the disease process. Novice and experienced examiners were able to apply this system as a supportive device for caries diagnostic and monitoring purposes. Sensitivity and specificity values varied depending on the cutoff values.

Occlusal caries: Evaluation of direct microscopy versus digital imaging used for two histological classification systems

OBJECTIVE Histology is frequently used as a gold standard to validate caries detection devices. Poor assessment consistency could lead to apparent changes in diagnostic accuracy. In multi-center, multi-examiner studies electronic transfer of information would be convenient, provided there is no deteriation in quality. This study tested the hypothesis that examiner reproducibility in the assessment of caries lesion depth when viewing photographic images of histological sections on a computer monitor, is comparable with viewing the same sections under a microscope using two histological classification systems. METHODS 166 investigation sites (96 teeth) were selected for visual examination (ICDAS-II) and sections made using a novel technique which reduced risk of section damage and allowed accurate allocation of section to each investigation site. Digital images of the sections were produced and four examiners viewed the sections under a microscope and on a separate occasion corresponding digital images on a computer monitor. Presence and extent of caries was scored according to two histological classification systems (Downer, ERK). RESULTS The inter- and intra-examiner reproducibility for both histological classification systems and both examination techniques was substantial to almost perfect (weighted kappa=0.63-0.90). Comparing the kappa values between microscopy and viewing digital images, there was no effect or only a small effect between both examination techniques (effect size 0.00-0.28). There was also a strong relationship between the two viewing techniques (r(s)=0.748-0.844). CONCLUSIONS Viewing digital images of tooth sections produces results comparable to viewing images directly under a microscope and therefore has potential benefits for multi-centre studies.

Impact of Scoring Single or Multiple Occlusal Lesions on Estimates of Diagnostic Accuracy of the Visual ICDAS-II System.

Carious lesions can occur at different sites on the occlusal surfaces of teeth and may differ in appearance and severity. This study aimed to evaluate how estimates of reproducibility and accuracy of ICDAS-II were affected when all lesions on occlusal surfaces, or only a representative lesion, were scored. 100 permanent teeth with 1–4 investigation sites on the occlusal surface were examined visually by four examiners. Serial sections of the teeth were assessed for lesion depth. Intra- and interexaminer reproducibility (weighted kappa values), sensitivity, and specificity were calculated for all investigation sites and for a randomly selected site per tooth. Comparing the kappa values for the whole sample and the independent sites, no effect or only a small effect was found. Comparing the areas under the ROC-curves no effect could be shown. Examining multiple sites on teeth leads to results comparable to when a single independent site is chosen per tooth.

Impact of measuring multiple or single occlusal lesions on estimates of diagnostic accuracy using fluorescence methods

Carious lesions can occur at different sites on the occlusal surfaces of teeth and may differ in appearance and severity. This study aimed to evaluate how scoring several lesions on occlusal surfaces, as opposed to only one representative lesion, affects estimates of reproducibility and accuracy of fluorescence-based devices. Thirty-six permanent teeth with 2-3 investigation sites (n = 82) were examined by two examiners using the laser fluorescence device DIAGNOdent pen (LF) and the fluorescence camera VistaProof (FC). Lesion depth was then assessed histologically in serial sections of the teeth. Intra-class-correlation coefficients (ICC) and areas under the ROC-curves were calculated for all investigation sites and for one randomly selected site per tooth. Comparing the reproducibility and the performance for the whole sample and the independent sites showed only a small effect or no effect. Measuring multiple sites on teeth with fluorescence devices only moderately influences performance compared to one site being investigated.

Survival of Inlays and Partial Crowns Made of IPS Empress After a 10-year Observation Period and in Relation to Various Treatment Parameters

UNLABELLED This study evaluated the long-term survival of inlays and partial crowns made of IPS Empress. For this purpose, the patient data of a prospective study were examined in retrospect and statistically evaluated. MATERIALS AND METHODS All of the inlays and partial crowns fabricated of IPS-Empress within the Department of Operative Dentistry at the School of Dental Medicine of Philipps University, Marburg, Germany were systematically recorded in a database between 1991 and 2001. The corresponding patient files were revised at the end of 2001. The information gathered in this way was used to evaluate the survival of the restorations using the method described by Kaplan and Meyer. RESULTS A total of n = 1624 restorations were fabricated of IPS-Empress within the observation period. During this time, n = 53 failures were recorded. The remaining restorations were observed for a mean period of 18.77 months. The failures were mainly attributed to fractures, endodontic problems and cementation errors. The last failure was established after 82 months. At this stage, a cumulative survival probability of p = 0.81 was registered with a standard error of 0.04. At this time, n = 30 restorations were still being observed. Restorations on vital teeth (n = 1588) showed 46 failures, with a cumulative survival probability of p = 0.82. Restorations performed on non-vital teeth (n = 36) showed seven failures, with a cumulative survival probability of p = 0.53. Highly significant differences were found between the two groups (p < 0.0001) in a log-rank test. No significant difference (p = 0.41) was found between the patients treated by students (n = 909) and those treated by qualified dentists (n = 715). Likewise, no difference (p = 0.13) was established between the restorations seated with a high viscosity cement (n = 295) and those placed with a low viscosity cement (n = 1329).

Phenotypic differences between red pulp capillary and sinusoidal endothelia help localizing the open splenic circulation in humans

The distribution of capillaries, sinuses and larger vessels was investigated by immunohistology in paraffin sections of 12 adult human spleens using a panel of antibodies. Double staining for CD34 and CD141 (thrombomodulin) revealed that capillary endothelia in the cords of the splenic red pulp and at the surface of follicles were CD34+CD141−, while red pulp sinus endothelia had the phenotype CD34−CD141+. Only in the direct vicinity of splenic follicles did sinus endothelial cells exhibit both antigens. Thus, splenic sinuses do not replace conventional capillaries, but exist in addition to such vessels. The endothelium in arterioles, venules and larger arteries and veins was uniformly CD34+CD141+. Anti-CD34 and anti-CD141 both additionally reacted with different types of splenic stromal cells. Differential staining of capillaries and sinuses may permit a three-dimensional reconstruction of serial sections to unequivocally delineate the “open” and “closed” splenic circulation in humans.

Influence of a high-speed polymerization method on the marginal integrity of composite fillings in Class-II cavities.

Abstract The aim of this study was to evaluate the effect of a rapid photopolymerization method on the marginal integrity of composite fillings. Ninety two-surface cavities were prepared in extracted human molars using the SonicSys preparation system. All cavities were bonded with one bonding agent (Syntac) and filled with a microfilled composite (Herculite XRV), a heavy filled composite (Z100 MP), and an Ormocer (Definite) in two increments. Each increment had a thickness of approximately 1.5 mm and was polymerized using either halogen light or the plasma light of Apollo 95 E. In this process, six trial groups each containing 15 fillings were created. After replicas were made, the test teeth were subjected to a thermocycling process of 2000 temperature cycles (5°C/55°C) followed by a wear simulation of 50,000 stress cycles each with 50 N. This was followed by the creation of a second set of replicas, quantitative margin analysis, and dye penetration. A significant (P<0.05) influence of the thermomechanical stress and a significant (P<0.05) influence of the factor ”material” were shown for the margin criterion ”continuous margin” using MANOVA. The factor ”light source” produced no significant influence (P=0.57) on the amount of continuous margin. During the dye penetration, no significant differences between the polymerization methods could be established with the materials Herculite XRV and Z100 MP (H-test according to Kruskall and Wallis). Only with the material Definite was a significantly higher dye penetration observed at the occlusal measuring point in the plasma light group. A rapid polymerization with high light intensity had no adverse effects on the margin quality within the limitations of this in vitro study. However the marginal integrity might have been influenced by the chosen adhesive system/composite resin combination, which does not represent the respective product line. Additionally, further studies ought to show which exposure time is necessary for a sufficient degree of conversion.