Effect of systemic antibiotics on clinical and patient-reported outcomes of implant therapy - a multicenter randomized controlled clinical trial

Objectives: To determine the effect of various systemic antibiotic prophylaxis regimes on patient-reported outcomes and postsurgical complications in patients undergoing conventional implant installation.

Material and methods: Three hundred and twenty-nine healthy adults in need of conventional implant installation were randomly assigned to one of four groups: (i) preoperatively 2 g of amoxycillin 1 h before surgery (positive control, PC), (ii) postoperatively 2 g of amoxycillin immediately following surgery (test 1, T1), (iii) preoperatively 2 g of amoxycillin 1 h before and 500 mg thrice daily on days 2 and 3 after surgery (test 2, T2), (iv) preoperatively 2 g of placebo 1 h before surgery (negative control, NC). Subjects were examined clinically by blinded examiners over 8 weeks after implant installation. In addition, Visual Analogue Scales (VAS) for pain, swelling, bruising and bleeding were obtained over 14 days. ANOVA was performed for the VAS. Chi-square tests were applied for postsurgical complications.

Results: All VAS scores were low for all groups and decreased over time (P < 0.001). There were no significant differences for the VAS scores between the various groups at any time point (P > 0.05). There was only a significant difference in flap closure at week 4, where NC had 5% of the subjects not achieving complete wound closure compared to 0% for the three other groups (P = 0.01), with no other significant differences for any postsurgical complications (P > 0.05).

Conclusion: For standard single implant placement, prophylactic systemic antibiotics either before or after, or before and after the surgical procedure do not improve patient-reported outcomes or prevalence of postsurgical complications.