Trueness, 3D Deviation, Time and Cost Comparisons Between Milled and 3D-Printed Resin Single Crowns.

The purpose of this in-vitro study was to compare trueness, 3D deviation, production time and costs of milled and 3D-printed resin single crowns. A total of 20 CAD-CAM resin single crowns were fabricated from 10 digital wax patterns designed on 10 tooth preparations available in a reference model. Standardized control linear measurements were performed with a CAD software. Each STL file was then used to fabricate two resins crowns - one milled and one 3D-printed. All crowns underwent physical linear measurements using a digital caliper. The crowns were then scanned using an intraoral scanner for assessing 3D deviation. Finally, time to produce a single crown, as well as costs and production rates of both methods were also compared. Both CAM methods did not present statistically significant differences in linear measurements, as compared to controls (P⟩.05). Furthermore, 3D-printed crowns had significantly greater deviations in cervical margins (P=.032) and occlusal surfaces (P=.041), as compared with milled crowns. Finally, 3D-printing took significantly longer to produce one single crown (P=.001), but with a cheaper and higher production rate than milling. These findings suggest that milling devices produce resin single crowns with smaller 3D deviations but more expensive costs, as compared with low-cost 3D printers.

Dental Public Health in Action: Experiences and Responses of Oral Health Care Professionals during the First Wave of the COVID-19 Pandemic in Malta.

Initial impetus for action: Maltese Oral Health Care Professionals (OHCP) experienced changes to clinical practice and redeployment during the COVID-19 pandemic. In the early stages, there were few data on the resultant changes to the provision of dental services or their impact on the wellbeing of dental professionals. Solutions Suggested: Two questionnaires were designed to explore different domains in OHCP working on the frontline of the COVID-19 pandemic as well as in other areas/sectors. The findings were intended to inform guidance documents and to better support the profession. Findings: Anxiety-provoking factors, challenges, and areas of concern of OHCP were identified and practical recommendations to support transitioning to the 'new normal' were presented. OHCP expressed anxiety about contracting COVID-19 from their workplace and passing infection to other family members, friends, or patients. As a result, OHCP expressed the need for better protective clothing, workplace ventilation, and air filtration systems. Future implications: Provision of adequate PPE for OHCP was a priority. New guidelines for dental practice were informed by the experiences of the particpating OHCP. University modules to enhance the resilience of OHCP were among the recommendations to support practitioners.