ObjectiveOpening of a healing abutment in two-stage implant systems is usually followed by a bad smell. Previous studies have found that presence of bacteria in microleakages of the implant-abutment interface results in further malodor. However, studies focusing on preventive treatments for this issue are scarce. Therefore, the aim of this study is to evaluate the effectiveness of two antimicrobial agents on prevention of malodor followed by opening the healing abutments.Materials and MethodsCurrent double-blinded randomized clinical trial was performed on 51 eligible patients who were referred for their exposure surgery. They were divided equally into three parallel groups. In two groups, either chlorhexidine or tetracycline was added to the internal surface of the fixtures before screwing the healing abutments. One group did not receive any intervention. Three to 4 weeks later malodor was scored by sniffing the healing abutments immediately after uncovering them (odorless = 0/odor = 1). The three groups were then compared regarding malodor scores.ResultsOur findings showed that malodor was more frequent in the control group (58.82%) in comparison with groups of intervention (17.65 and 23.53%). There was a statistically significant difference between malodor in patients in whom antimicrobial agents (chlorhexidine and tetracycline) were used in their implants and the control group (p-value = 0.023). However, malodor in the chlorhexidine group and tetracycline group did not show any significant difference (p-value = 1).ConclusionBased upon the data from this study, it appears that local antimicrobial agents including chlorhexidine and tetracycline result in less malodor production within the implant-abutment interface.Clinical SignificanceA specific type of malodor is commonly seen after opening the healing abutment of a two-stage dental implant. Not only this issue is noticed by the dentist, but also annoyed the patient. Using local antimicrobial agents in the fixtures is likely to be a simple, easily applicable solution that satisfies both patients and dentists, and eliminates the possibility of further inflammation.