Background: The use of amalgam in Dentistry has decreased since the 1980s. This study aimed to (i) assess the time trend in the usage of amalgam and composite in posterior teeth at Griffith University Dental Clinic from 2010 to 2019; (ii) to test whether this trend varied according to the dental health provider. Methods: We analyzed clinic records from 2010 to 2019. Prais-Winsten analyses were performed, and the average annual percentages change (AAPC) for amalgam and composite was estimated. Results: There were 397,013 procedures, including 80,995 direct posterior restorations. Amalgam use decreased from 12.9% in 2010 to 0.5% in 2019 among students, while composite use has increased from 87.1% to 99.5% of posterior restorations. The annual increase of composite was 1.4% per year for students, while amalgam decreased by 30.2% per year on average. A similar trend was noted among the dentists. Conclusions: A significant decrease in the use of amalgam was observed over time for both students and professionals. This trend raises questions about curriculum reviews, focusing on the repair, maintenance, and safe removal of amalgam while reinforcing the learning on Minimally Invasive Dentistry and composite restorations based on the patient's caries risk.