Objectives: Doxycycline hyclate is a controlled-release doxycycline polymer which can locally be applied. This study aimed to assess the effects of the prophylactic application of doxycycline hyclate at the implant–abutment interface on the short-term outcomes of implant therapy.
Method and materials: The present split-mouth randomized clinical trial included 20 subjects who received two mandibular implants bilaterally (40 implants in total). In the test side (n = 20), doxycycline hyclate was injected at the implant–abutment interface at the time of delivery of final prosthesis. No intervention was performed for the control side (n = 20). The marginal bone level on mesial and distal implant surfaces, bleeding on probing, pocket probing depth, and incidence of peri-implant mucositis were recorded at baseline and after 3, 6, and 12 months.
Results: Significant differences were found between the test and control sites, all favoring the test group, for marginal bone level changes at mesial and distal implant surfaces as well as for changes in pocket probing depth after 6 and 12 months. Furthermore, the numbers of implants with bleeding on probing and risk of developing peri-implant mucositis were significantly greater in the control group compared to the test group at 3-months, 6-months, and 12-months following baseline.
Conclusions: Within the limitations of this study, it can be concluded that prophylactic application of doxycycline hyclate at the implant–abutment interface results in reduced crestal bone resorption and pocket probing depth levels. In addition, it reduces the risk of developing peri-implant mucositis.