Background Supportive periodontal care (SPC) is important in maintaining periodontal treatment outcomes. Hospital services provide specialist periodontal care at high costs. On completion of treatment, patients are discharged back to the general dental practitioner (GDP) to provide SPC. This project aimed to evaluate the change in GDPs' understanding of SPC over more than 20 years.Method A validated questionnaire about SPC was sent to GDPs during 1996 (397) and 2020 (300), with a response rate of 74% and 52%, respectively. The anonymous data were entered on a Microsoft Excel spreadsheet for analysis.Results In total, 98.5% of the GDPs in 1996 and 97% in 2020 perceived SPC to be highly important. Additionally, 49% in 2020 had a better understanding of SPC when compared to 1996 (42%). Finally, 70-74% (1996, 2020) of the GDPs indicated that they were responsible for SPC; however, 13-16% said that they were not.Conclusion and clinical relevance Notwithstanding the lower response rate in 2020, there has been an improvement in understanding and awareness of responsibility of SPC among GDPs. Reported challenges of provision were related to education and funding. If GDPs are to effectively deliver SPC, education and current funding should be addressed to prevent compromised treatment outcomes for patients. The majority of locally referring general dental practitioners (GDPs) have an understanding of supportive periodontal care (SPC).The locally referring GDPs need to be provided with clear discharge protocols and SPC regimes to improve delivery of SPC in general dental practice.Future changes in the remuneration system in general dental services should allow for the provision of tailored SPC.