Impression Taking With a Focus on Interdental Areas: a Clinical Update

Objectives: In 2019, our research group for the first time published clinical data on the ability to display interdental areas (IAs), comparing the established conventional impression (CVI) and four intraoral scanners (IOS). In contrast to the CVI, the IOS showed a significantly higher percentage of IAs, but there was still room for improvement. Due to the continuous development of IOS hardware and software, the aim of this study was to investigate whether the to investigate whether the ability to display IAs has improved with the latest IOS.
Methods: The lower jaw of 30 patients (50% female, mean age 63.1±7.6 years) were scanned with five IOS (CS3800, CS, Carestream Dental; i700, i7, Medit; iTeroElement5D, iT, Align Technology; Primescan, PS, Dentsply Sirona; Trios4, T4, 3Shape) between January and February 2022. IAs were classified according to their papillary height (class I/II) and area (anterior/posterior). The percentage of displayed IAs in relation to the absolute IAs was determined using 3D analysis software (GOMInspect, gom). Median test was used for statistical analysis (p< .05).
Results: Overall, PS (mean 12.8%; confidence interval 9.8-15.7%) and iT (12.7%; 9.7-15.7) displayed IAs better than T4 (9.0%; 6.3-11.7%), i7 (8.9%; 6.2-11.6%), and CS (3.9%; 2.0-5.9%). Class II and anterior areas were significantly better displayed than class I and posterior areas (p<.05), regardless of the IOS used.
Conclusions: Compared to the 2019 data, the 2022 IOS showed comparable or even worse results. Thus, even with the latest IOS, correct display of IAs remains a challenge.