This study examined the compatibility of 3D-printed artificial teeth and extracted teeth by combining oral cone-beam computed tomography (CBCT) and multi-jet printing technology to print the extracted teeth in vitro. The 3D-printed artificial teeth were then used to choose a master gutta-percha with an appropriate working length and taper to fill root canals. The quality of root canal-filling was evaluated via X-ray. Twenty orthodontically extracted premolars with a single root canal were collected and CBCT-scanned, and the scan data were extracted and converted to 3D models using MIMICS software, which in turn were used to 3D-print artificial teeth using multi-jet printing technology. The artificial teeth were re-scanned by CBCT to acquire 3D scan data, and the 3D deviation between the 3D-printed artificial teeth and extracted teeth was analyzed using Geomagic Studio software, in which the root canal cross-sections at 3 mm, 6 mm and 9 mm from the apex were measured and statistically analyzed. Clinically, three cases of adult anterior teeth with root canals were treated, and artificial teeth for root canal preparation were 3D-printed using multi-jet printing technology. A master gutta-percha with an appropriate working length and taper was matched and chosen to fill the root canal based on the root canal of the 3D-printed artificial tooth, and the quality of filling was evaluated by X-ray. An analysis of the 3D deviation between the 3D-printed artificial teeth prepared by combining oral CBCT and multi-jet printing technology and the original extracted teeth showed that the teeth were well-matched. There were no significant differences between the teeth regarding root canal cross-sections at 3 mm, 6 mm and 9 mm from the apex (P > 0.05). In the three clinical cases, postoperative X-ray examination showed that the root canal filling with the master gutta-percha prepared by in vitro matching based on the 3D-printed artificial teeth was good quality. The combination of CBCT and multi-jet printing technology generated accurate 3D-printed artificial teeth, which provided a master gutta-percha with a matching working length and taper for the in vivo root canal, thus providing a new approach to improve the rate of correct fill-ins in root canal fillings.

Background Paper-plastic sterilization pouches are essential in healthcare for preventing instrument contamination. However, sealing defects in these pouches can jeopardize patient safety. To address this issue, our study uses Root Cause Analysis (RCA), aiming to identify contributing factors to these defects and propose practical solutions. Through this, we aim to enhance the overall sterilization process Material/Methods A retrospective analysis was conducted on 35,762 instruments sterilized and packaged in paper-plastic pouches at our hospital’s Central Sterile Supply Department (CSSD) across two periods: July 2020 to June 2021 (pre-RCA, 17,563 instruments) and September 2021 to August 2022 (post-RCA, 18,199 instruments). We evaluated RCA scores, packaging personnel’s perceptions of sealing quality, and sealing defect rates before and after RCA implementation. Results Root causes for sealing defects included lack of a standardized inspection procedure, inadequately sized packing table, missed inspections, incorrect distribution procedures, inadequate staff training, and insufficient lighting through the pass-through window between storage and distribution rooms. Among these, lack of a standardized inspection procedure, small packing table size, and missed inspections were statistically significant risk factors ( P <0.05). The sealing defect rate decreased from 0.15% pre-RCA implementation to 0.07% post-RCA implementation. Conclusions Implementing RCA has been shown to effectively enhance the CSSD staff’s perception of sealing quality and significantly reduce the incidence of sealing defects in paper-plastic pouches. Thus, RCA serves as an invaluable tool for quality improvement in sterilization packaging processes.

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