Fig 1.
Example of a 3D scan and the associated 2D intraoral images.
The left side shows a completely scanned lower dental arch, the right side excerpts of this 3D scan in a mesial-lateral and distal-lateral view of tooth 36 with the associated 2D intraoral images at baseline (T1).
Fig 2.
Different degrees of plaque amount recorded with 3D scan and 2D intraoral camera at the three time points (T1, T2, T3).
A, C, E: 3D scan of the vestibular surface of a tooth 36 and B, D, E the associated 2D intraoral image; A, B: habitual amount of plaque (T1); C, D: amount of plaque after 72h without oral hygiene (T2); E, F: amount of plaque after brushing (T3).
Fig 3.
Timeline of the study procedure.
Overview of the chronological sequence of the evaluations, including the determination of inter- and intra-examiner agreement.
Table 1.
Inter- and intra-examiner reliability as mean±SD of the Kappa scores of the different areas of the index per time points T1-T3.
Table 2.
Percentages of plaque containing RMNPI areas of all RMNPI areas (mean (SD)).
Fig 4.
Percentages of plaque containing RMNPI areas (mean±SD).
16 and 36: upper right and lower left first molar, 24 and 44: upper left and lower right first premolar, 21 and 41: upper left and lower right first incisor. Light grey columns: T1 (habitual oral hygiene level); dark grey columns: T2 (after abstaining from oral hygiene for 72 h); medium light grey: T3 (after habitual brushing). Within a time point: left column: clinical investigation; middle column: 2D images; right column: 3D images.
Fig 5.
Bland-Altman plots evaluating the agreement between the percentages of plaque containing RMNPI areas obtained from 2D and 3D images with the clinical evaluation.
A and B: vestibular surfaces, C and D: oral surfaces. The solid line indicates the mean difference of the methods of comparison; the broken lines indicate the 95% limits of agreement (mean±1.96xSD). The light grey lines in B show the regression line with 95% confidence intervals indicating a significant albeit small proportional difference, which was not found in A, C and D.
Table 3.
Kappa coefficients with 95%CI in brackets for the individual areas of the RMNPI, all time points and areas are merged.
Fig 6.
Agreement of the two image-based methods with the clinical examination in the areas of the RMNPI separated into the oral and vestibular areas.
A and C: 2D images compared to the clinical examination, B and D: 3D images compared to the clinical examination; A and B: oral surfaces, C and D: vestibular surfaces. Areas A, D, G = mesial; areas C, F, H = distal. Strength of agreement according to [14]: dark gray: 0.81–1 (almost perfect), light gray: 0.61–0.8 (substantial), white: 0.41–0.60 (moderate). Asterisk: in this area, the kappa score was 0.269 (fair).