Accuracy and Reliability of Intraoral 3D Scans for Diagnostic Evaluations in Nursing Home Residents

To evaluate the accuracy and reliability of intraoral 3D scans for assessing the oral health of older patients living in nursing homes.

One examiner recorded missing teeth, restorations, caries lesions and oral hygiene (Geriatric-Debris-Index Simplified [GDI-S] ≥ 1.9) in nursing home residents using visual-tactile diagnostics (reference test) and afterwards obtained intraoral scans with an intraoral scanner (TRIOS 4, 3Shape). Two other independent investigators and the clinical examiner assessed only the scans to delineate the same diagnostic outcomes. For these outcomes, we assessed accuracy, sensitivity, specificity and the Area-under-the-Receiver-Operating-Characteristics Curve (AUROC). Kappa values (κ) were calculated to evaluate inter-examiner and intra-examiner reliability after re-examination by all examiners after a minimum interval of 3 weeks.

Forty-three partially dentate patients (65-95 years of age) in need of care living in four nursing homes with a total of 486 teeth (mean [SD]: 11 [9] teeth per patient) were examined. Scans were perfectly accurate for detecting missing teeth (AUROC [sensitivity/specificity]: 1 [1/1]) and showed high accuracy for detecting restorations (0.96 [0.93/0.98]), too. Accuracy was lower to detect caries (0.77 [0.58/0.97]) and insufficient for oral hygiene (0.76 [0.54/0.99]). Agreement between examiners was perfect for missing teeth (κ: 1), very good for the detection of restorations (0.94), and good for caries or insufficient oral hygiene (0.73 and 0.72, respectively).

Scans were suitable for basic diagnostic evaluations but showed considerable shortcomings in detecting caries and poor oral hygiene. Assessing scans was relatively reliable.

Using scans may allow telemedical assessments of nursing home residents, but users should be aware of the differential accuracy for different diagnostic targets.