Effect of a novel isolation device on the accuracy of mandibular complete-arch digital impressions: A clinical study

To assess the effect of a novel isolation device "Ararat" on the accuracy and scanning time of complete-arch mandibular digital impressions, according to varying levels of operator experience. "Ararat" is an isolation device that's installed on the intraoral scanner tip and aids in fluid control by emitting pressurized air while scanning to dry intraoral surfaces.

A mandibular complete-arch impression was made using polyvinyl siloxane (PVS) and digitized with a calibrated desktop scanner (Ceramill Map 400) to create the reference STL file (RSTL). Two groups were analyzed: with device (W) and without device (WO), each subdivided by operator experience (low [L], medium [M], and high [H]). This resulted in six subgroups: LW, LWO, MW, MWO, HW, and HWO. Twenty-two scans (n = 22) were captured per subgroup using an intraoral scanner (TRIOS 3), with scanning times recorded. Trueness was determined by superimposing subgroup scans onto the RSTL to calculate 3D root mean square (RMS) deviations. Precision was evaluated by superimposing randomly paired scans within each subgroup. Data distribution and variance were assessed using Kolmogorov-Smirnov and Levene's tests, and a two-way ANOVA analyzed the effects of isolation and experience level on trueness, precision, and scanning time (α=0.05).

No significant difference was found in overall trueness between W and WO groups (P = 0.563). Trueness improved significantly for MW with the device (P = 0.005). Precision decreased for LW (P ≤ 0.001) but increased for MW (P = 0.003) with the device. Scanning time was consistently longer with the device, regardless of experience level (P ≤ 0.001).

The "Ararat" device did not significantly improve overall trueness but demonstrated operator-dependent effects on accuracy. Further studies should explore its utility in diverse clinical scenarios.

The device may enhance scanning accuracy for certain operators.