Interventions for replacing missing teeth: antibiotic prophylaxis for dental implant placement without bone augmentation procedures

RATIONALE: Some dental implant failures may result from bacterial contamination at implant insertion, and biomaterial-related infections are difficult to treat. Antibiotic prophylaxis is generally indicated for patients at risk of infective endocarditis or with reduced host response, surgery at infected sites, extensive or prolonged procedures, or implantation of large foreign materials. Various prophylactic regimens, including short-term protocols, have been proposed to reduce post-implant infections. However, concerns about adverse events and antibiotic resistance make prophylactic antibiotic use in implant dentistry controversial. OBJECTIVES: To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement not subjected to concomitant bone augmentation procedures versus no antibiotic or placebo administration and, if antibiotics are beneficial, to determine which type, dosage, and duration is the most effective. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the WHO ICTRP, and ClinicalTrials.gov from January 2013 to 19 November 2025. ELIGIBILITY CRITERIA: We included randomised controlled trials (RCTs) evaluating the efficacy of systemic prophylactic antibiotics at dental implant placement. We included trials that had a minimum follow-up of three months, included at least 10 participants per study arm, and involved implant placement performed without concomitant bone augmentation procedures. OUTCOMES: Implant failures, prosthesis failures, postoperative infections, and adverse events, assessed up to one year following implant placement. RISK OF BIAS: Two review authors assessed the risk of bias independently and in duplicate using the Cochrane RoB 1 tool. SYNTHESIS METHODS: Where appropriate, we pooled data in meta-analyses using random-effects models, and expressed results as risk ratios (RRs) with 95% confidence intervals (CIs). We assessed heterogeneity using the I² statistic and the certainty of the evidence using GRADE. INCLUDED STUDIES: We included 15 RCTs (2874 participants). Ten RCTs compared antibiotics versus placebo or no antibiotics; five RCTs compared single administration of antibiotics versus multiple administration of antibiotics; two RCTs compared preoperative versus postoperative antibiotic administration; and one RCT compared different antibiotics (amoxicillin versus clindamycin). Most studies used a single preoperative oral dose of 2 g. SYNTHESIS OF RESULTS: We judged eight trials to be at low risk of bias, and the remaining seven trials as at high risk of bias. Comparison 1: Antibiotics compared to placebo/no antibiotics Antibiotic prophylaxis probably reduces implant failures compared with placebo or no antibiotics (RR 0.34, 95% CI 0.22 to 0.53; I² = 0%; 10 studies, 1919 participants; moderate-certainty evidence), corresponding to an absolute reduction from 80 to 27 per 1000 participants and a number needed to treat for an additional beneficial outcome of 19. Antibiotics probably also reduce prosthesis failures (RR 0.38, 95% CI 0.23 to 0.60; I² = 0%; 9 studies, 1864 participants; moderate-certainty evidence) and postoperative infections (RR 0.55, 95% CI 0.33 to 0.93; I² = 0%; 10 studies, 1919 participants; moderate-certainty evidence). The effect of antibiotics on adverse events is very uncertain. Adverse events occurred in only two studies (631 participants); in seven other studies (1269 participants), there were no adverse events in either study group (RR 0.63, 95% CI 0.08 to 5.09; I² = 0%; 9 studies, 1900 participants; very low-certainty evidence). Comparison 2: Single administration of antibiotics compared to multiple administration of antibiotics There may be little to no difference between single and multiple administration of antibiotics for implant failures (RR 0.55, 95% CI 0.20 to 1.55; I² = 0%; 5 studies, 760 participants; low-certainty evidence) or postoperative infections (RR 0.57, 95% CI 0.21 to 1.50; I² = 8%; 5 studies, 760 participants; low-certainty evidence). The evidence for the effect on prosthesis failures is very uncertain (RR 0.17, 95% CI 0.02 to 1.44; I² = 0%; 5 studies, 760 participants; very low-certainty evidence). The evidence regarding adverse events is also very uncertain. Three studies assessed adverse events (430 participants), but events only occurred in two studies (RR 0.63, 95% CI 0.04 to 11.05; I² = 44%; 3 studies, 430 participants). One major allergic reaction requiring hospitalisation occurred in the multiple administration group. Comparison 3: Preoperative antibiotics versus postoperative antibiotics There may be little to no difference between preoperative and postoperative antibiotic administration for implant failures (RR 2.12, 95% CI 0.19 to 23.06; I² not applicable; 2 studies, 293 participants; very low-certainty evidence), prosthesis failures (RR 2.12, 95% CI 0.19 to 23.06; I² not applicable; 2 studies, 293 participants; very low-certainty evidence), or postoperative infections (RR 0.79, 95% CI 0.18 to 3.48; I² not applicable; 2 studies, 293 participants; very low-certainty evidence). The evidence is very uncertain for all outcomes. One study reported no adverse events in either group (0/25 versus 0/25). Comparison 4: Different antibiotics: amoxicillin (2 g) versus clindamycin (600 mg) There may be little to no difference between amoxicillin and clindamycin for implant failures (RR 2.93, 95% CI 0.12 to 69.83; 1 study, 81 participants; low-certainty evidence), prosthesis failures (RR 2.93, 95% CI 0.12 to 69.83; 1 study, 81 participants; low-certainty evidence), or postoperative infections (RR 0.98, 95% CI 0.14 to 6.59; 1 study, 81 participants; low-certainty evidence). Adverse events were reported only in the clindamycin group (RR 0.33, 95% CI 0.01 to 7.76; 1 study, 81 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: Antibiotic prophylaxis at dental implant placement probably reduces early implant failures. This finding is mainly based on trials comparing a single preoperative oral dose of amoxicillin (usually 2 g one hour before surgery) with placebo or no antibiotics (number needed to treat for an additional beneficial outcome ≈ 19). Antibiotic prophylaxis probably also reduces prosthesis failures and postoperative infections. The evidence for adverse events is very uncertain because events were rare and inconsistently reported. The available evidence is insufficient to determine the optimal regimen, including single- versus multiple-dose regimens, pre- versus postoperative administration, or whether antibiotics other than amoxicillin offer additional benefit. One allergic reaction requiring hospitalisation was reported, highlighting that antibiotic prophylaxis should be used only when proven effective and clinically justified. FUNDING: This Cochrane review was funded (in part) by Vita-Salute San Raffaele University, Milan. REGISTRATION: Protocol (2003): doi.org/10.1002/14651858.CD004152. Original review (2008): doi.org/1002/14651858.CD004152.pub2. Review update (2010): doi.org/10.1002/14651858.CD004152.pub3. Review update (2013): doi.org/10.1002/14651858.CD004152.pub4.