Background:　Dental　outpatient　departments,　characterized　by　close　proximity　and　unmasked　patients,　present　a　considerable　risk　of　respiratory　infections　for　health　care　workers　(HCWs).　However,　the　lack　of　comprehensive　data　on　close　contact　(＜　1.5　m)　between　HCWs　and　patients　poses　a　significant　obstacle　to　the　development　of　targeted　control　strategies.　Methods:　An　observation　study　was　conducted　at　a　hospital　in　Shenzhen,　China,　utilizing　depth　cameras　with　machine　learning　to　capture　close-contact　behaviors　of　patients　with　HCWs.　Additionally,　questionnaires　were　administered　to　collect　patient　demographics.　Results:　The　study　included　200　patients,　10　dental　practitioners,　and　10　nurses.　Patients　had　significantly　higher　close-contact　rates　with　dental　practitioners　(97.5%)　compared　with　nurses　(72.8%,　P　＜　.001).　The　reason　for　the　visit　significantly　influenced　patient-practitioner　(P　=　.018)　and　patient-nurse　(P　=　.007)　closecontact　time,　with　the　highest　values　observed　in　prosthodontics　and　orthodontics　patients.　Furthermore,　patient　age　also　significantly　impacted　the　close-contact　rate　with　nurses　(P　=　.024),　with　the　highest　rate　observed　in　patients　below　14　years　old　at　85%　[interquartile　range:　70-93].　Conclusions:　Dental　outpatient　departments　exhibit　high　HCW-patient　close-contact　rates,　influenced　by　visit　purpose　and　patient　age.　Enhanced　infection　control　measures　are　warranted,　particularly　for　prosthodontics　and　orthodontics　patients　or　those　below　14　years　old.　(c)　2024　Association　for　Professionals　in　Infection　Control　and　Epidemiology,　Inc.　Published　by　Elsevier　Inc.　All　rights　are　reserved,　including　those　for　text　and　data　mining,　AI　training,　and　similar　technologies.