Dental implant placement is a clean-contaminated (class II) surgical procedure that involves the risk of bacterial contamination during insertion and subsequent biofilm formation, which can lead to non-integration and implant loss [20, 21]. Infected biomaterials like titanium or zirconia are often resistant to antibiotics that are normally effective against periodontal bacteria, often necessitating implant removal [20]. Infection risk can be influenced by the surgeon’s skill and maintenance of asepsis during surgery. Additionally, perioperative antibiotic prophylaxis can help reduce the risk of periimplantitis and implant loss. The effectiveness of prophylactic antibiotics in implant surgery has been studied in various randomized controlled trials over the years [13]. Limited evidence from these trials, each with a small patient cohort, and their meta-analyses indicates that antibiotic prophylaxis is effective to prevent implant failure or the development of postoperative infections with a NNT ranging from 14 to 143 [10,11,12,13].

The use of antibiotic prophylaxis to prevent surgical site infections is well established in orthopedic and general surgery, with evidence-based guidelines in place [22]. However, its use in oral surgical procedures, particularly oral implant placement, is less clear. The 4th European Association for Osseointegration (EAO) Consensus Conference 2015 advised against antibiotic prophylaxis for low-risk interventions in healthy patients, suggesting it is beneficial only in complex cases (e.g., patients requiring grafting procedures or immediate placement in extraction sockets) and/or compromised patients, without specifying antibiotics or dosing regimens [14]. In contrast, the Spanish Society of Implants (SEI) recommends prescribing antibiotic prophylaxis even in routine situations for healthy patients, advising a single aminopenicillin dose 1 h before surgery [17]. For immediate dental implants (even without chronic infection of the tooth to be extracted) or sinus lifts, SEI advocates for postoperative continuation of the prophylactic antibiotic regimen for up to 9 days [17]. This approach contrasts with current principles in general surgery and periodontal plastic surgery, which state that there is no evidence to support postoperative antibiotic prophylaxis and thus no indication for it [23]. In Germany, no comprehensive guideline exists for antibiotic prophylaxis in implant surgery. Although routine use is debated, some guidelines recommend prophylaxis for high-risk patients. The S3 guideline advises a single preoperative antibiotic dose for diabetic patients undergoing dental implantation [16]. Similarly, systemic antibiotic prophylaxis is recommended for patients on antiresorptive therapies, such as bisphosphonates or denosumab, during jaw surgeries, including tooth extractions and implant placements [24, 25]. This also applies to patients who have undergone jaw radiotherapy [26].

Given the unclear and sometimes conflicting information in the literature regarding antibiotic prophylaxis in dental implant surgery, our study aimed to characterize antibiotic prescribing habits for oral implant surgery in Germany. Among the participating implantologists, 74.8% administered antibiotic prophylaxis to all their patients, indicating that roughly three-quarters of German implantologists routinely prescribe antibiotic prophylaxis. In comparison, studies from other European countries show that only 23% of implantologists in Turkey and 44% in the Netherlands routinely prescribe antibiotics [19, 27]. In contrast, the figures for the UK and Sweden are similar to those in Germany, at 72% and 74%, respectively [28, 29].

Our results suggest that the minority of implantologists who use antibiotic prophylaxis on a case-by-case basis consider patient-related and procedural risk factors. The strongest predictors of prophylactic antibiotic use were the patient’s diagnosis of cardiovascular disease, whether bone augmentation was performed, and the timing of dental implant insertion—immediate, early, or delayed—with ORs between 3.1 and 7.0. Factors such as the patient’s age had no influence.

Known risk factors for implant failure include smoking, systemic conditions (e.g., uncontrolled diabetes, osteoporosis, immune disorders), medication use (e.g., bisphosphonates), and previous radiation treatment [30,31,32]. We did not evaluate all these factors to avoid overloading the questionnaire, which might have affected the response rate. Furthermore, we aimed to observe the implantologists’ practices with minimal influence, as asking about specific risk factors might have sensitized them and influenced their use of antibiotic prophylaxis.

German implantologists use a narrow range of antibiotics, primarily aminopenicillins (with or without a beta-lactamase inhibitor) for two-thirds of prescriptions and clindamycin for the remaining third. These drugs were historically recommended for endocarditis prophylaxis, another important indication for prophylactic antibiotic use in dentistry. However, the 2023 European Society of Cardiology guidelines no longer recommend clindamycin for endocarditis prophylaxis due to its association with adverse events, including fatal and non-fatal Clostridioides difficile infections. This revised risk–benefit assessment may also be relevant for the perioperative use of clindamycin in implant surgery, especially as clindamycin is less effective in preventing implant failure than other antibiotics [33] and even failed to show preventive efficacy compared to placebo [34, 35]. Additionally, the use of clindamycin during sinus augmentation has been associated with an increased risk of graft failure compared to amoxicillin [36]. Although clindamycin use was reduced in bone augmentation cases compared to routine interventions, its overall frequent use, as observed in our study, is not justified given the current evidence.

Common bacteria causing implant infections include streptococci, anaerobic gram-negative rods, anaerobic gram-positive cocci, and anaerobic gram-negative cocci. Bacterial samples obtained during maxillary sinus elevations predominantly consisted of Streptococcus species (45%), mainly Streptococcus viridans, followed by Staphylococcus species (25%), Enterobacteriaceae (25%), and Haemophilus influenzae (5%) [37]. The most effective antibiotics in that study were ampicillin, amoxicillin–clavulanic acid, and ciprofloxacin [37], supporting the preferred use of aminopenicillins for antibiotic prophylaxis. Determining an alternative antibiotic for prophylaxis in implant surgery if aminopenicillins are contraindicated, such as due to allergies, remains challenging. Based on a study comparing single doses amoxicillin with clarithromycin in terms of surrogate endpoints (specific proinflammatory cytokine and chemokine concentrations in peri-implant crevicular fluid and gingival crevicular fluid) [38], the Spanish Society of Implants recommends the macrolide clarithromycin in its guidelines [17].

Our study revealed that more than three-quarters of patients received postoperative antibiotics despite no clear evidence that this improves outcomes in terms of osseointegration, reduced incidence of postoperative infections, or implant survival. In one study, patients treated with postoperative antibiotics experienced greater peri-implant vertical bone loss up to the 6-month follow-up but showed less bone loss in subsequent intervals up to 60 months [39]. Another study on healthy patients undergoing implant surgeries without additional bone grafting found that systemic postoperative antibiotics did not influence peri-implant crestal bone change or postoperative morbidities compared to preoperative single-dose antibiotics [40]. Additionally, postoperative antibiotics were not superior to a preoperative single-dose regimen regarding postoperative infection rates or implant failure in patients undergoing implant surgery, including those with guided bone regeneration but excluding those requiring sinus lift surgery [41]. The marginal benefits, if any, of postoperative antibiotic prophylaxis are outweighed by the risks of adverse effects on the gastrointestinal flora and the accelerated development of bacterial resistance. The Spanish Society of Implants provides only a low-level grade D recommendation for postoperative antibiotic prophylaxis, limited to special situations such as immediate dental implantations and implantations with sinus lifts [17].

We found that the type of training dentists undergo to become implantologists significantly influences their use of antibiotic prophylaxis. Developing a national or European guideline on antibiotic prophylaxis in implant dentistry, which is currently lacking, would standardize its evidence-based use in Germany.

A limitation of the study is that we did not record known patient-related risk factors for implant failure, such as diabetes mellitus, bone antiresorptive therapies, immunosuppression, or smoking. We excluded these factors for several reasons: (a) they have been extensively studied, (b) simplifying the survey was intended to encourage participation from implantologists and improve response rates, and (c) we aimed to minimize the survey’s impact on the prospective observation of prescription practices. However, unlike most previous surveys on the topic, our method of prospectively collecting data from at least 10 consecutive cases from each implantologist enabled us to gather and analyze real-world data.