Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 µm, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 µm, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

Purpose: The strategy of latent tuberculosis infection (LTBI) treatment in household tuberculosis (TB) contacts has been expanding in South Korea. However, there is little evidence of the cost-effectiveness of LTBI treatment in patients over 35 years of age. This study aimed to evaluate the cost-effectiveness of LTBI treatment among household TB contacts in different age groups in South Korea. Materials and Methods: An age-structured model of TB was developed based on the reports from the Korea Disease Control and Prevention Agency and the National Health Insurance Service. Quality-adjusted life-years (QALY) and the averted number of TBrelated deaths were estimated along with discounted costs for a measure of incremental cost-effectiveness ratios. Results: The number of cumulative active TB cases would decrease by 1564 and 7450 under the scenario of LTBI treatment for those aged <35 years and <70 years, respectively, relative to the no-treatment scenario. The treatment strategies for patients aged 0 to <35 years, <55 years, <65 years, and <70 years would add 397, 1482, 3782, and 8491 QALYs at a cost of $660, $5930, $4560, and $2530, respectively, per QALY. For the averted TB-related deaths, LTBI treatment targeting those aged 0 to <35 years, <55 years, <65 years, and <70 years would avert 7, 89, 155, and 186 deaths at a cost of $35900, $99200, $111100, and $115700 per deaths, respectively, in 20 years. Conclusion The age-specific expansion policy of LTBI treatment not only for those under 35 years of age but also for those under 65 years of age among household contacts was cost-effective in terms of QALYs and averted TB deaths.