Objective To extract and summarize the clinical registration information of periodontitis registered in the US ClinicalTrials.gov and Chinese Clinical Trial Registry(ChiCTR),and further analyze the registration characteristics of periodontitis clinical trials.Methods The ClinicalTrials.gov and ChiCTR data-bases were searched and compiled for periodontitis clinical registration information from 2000 to December 26,2024,including registration number,country/region of registration,annual number of registered projects,sample size,study type and design,study phase,and trial progress status.Results As of December 26,2024,a total of 520 242 registered clinical trials were retrieved from the ClinicalTrials.gov registry platform,of which 1 542(0.30%)were related to periodontitis.There were 189(12.26%)studies on periodontitis-related pro-jects in Turkey,while a total of 37(2.4%)projects were initiated by researchers in China,which ranked ninth.The Chinese Clinical Trial Register(ChiCTR)had 92 954 registered projects,of which 165 were on pe-riodontitis,and most of them were conducted by well-known affiliated hospitals and stomatology hospitals.The number of registrations in the ClinicalTrials.gov database increased year by year and reached a peak in 2022(146 registrations).Trial designs were focused on interventional and observational studies.ClinicalTri-als.gov study phases were focused on phases 2 and 4,while ChiCTR was clustered at phase 0(pre-registra-tion).Conclusion The number of clinical registrations for periodontitis in China's database is relatively low,and despite a steady upward trend,there is still a gap compared with other countries internationally.Future re-search should focus on how to encourage more oral health related research institutions to register on the plat-form and how to increase the sample size.