Reliability, or repeatability, of permanent tooth staging techniques is usually expressed as Cohen's Kappa. This single value obscures information about the quantity and allocation of disagreements. In this study we assess and compare intra-observer reliability of permanent tooth staging techniques described by Nolla, Moorrees et al. and Demirjian et al. The sample was panoramic radiographs of healthy dental patients made up of 100 males and 100 females aged 6-15 years. All permanent teeth on the left side (excluding third molars) were scored twice. Weighted Kappa and percentage agreement were calculated. Results show Kappa values for all teeth combined as 0.918, 0.922 and 0.938 for Demirjian (number of teeth N = 2682), Nolla (N = 2698) and Moorrees (N = 2674) respectively. A comparison of Kappa values between upper and lower teeth showed marginally higher values for upper incisors and lower molar for all three scoring methods. Small differences in Kappa values were noted between tooth types with the upper first molar having smaller values than other teeth. Percentage agreement ranged from 81 % (Moorrees), 86 % (Nolla) to 87 % (Demirjian). Tooth stage differences between first and second assessments were not more than one stage. Our findings show that Demirjian scoring is marginally more reliable than Nolla or Moorrees. We suggest that (1) data for reliability are tabulated in full to show the quantity and allocation of disagreement between first and second readings, and (2) that the reliability sample is sufficiently large with a wide age range to include multiple different tooth stages.
In this work, we presented experimental observation on solution-processed bulk heterojunction organic photodiode using vanadyl 2,11,20,29-tetra tert-butyl 2,3 naphthalocyanine (VTTBNc) as a p-type material. VTTBNc is blended with two different acceptors, which are PC61BM and PC71BM, to offer further understanding in evaluating the performance in organic photodiode (OPD). The blend film of VTTBNc:PC71BM with a volumetric ratio of 1:1 exhibits optimized performance in the VTTBNc blend structure with 2.31 × 109 Jones detectivity and 26.11 mA/W responsivity at a -1 V bias. The response and recovery time of VTTBNc:PC71BM were recorded as 241 ms and 310 ms, respectively. The light absorption measurement demonstrated that VTTBNc could extend the light absorption to the near-infrared (NIR) region. The detail of the enhancement of the performance by adding VTTBNc to the blend was further explained in the discussion section.