It's not the penicillin allergy — it's the alternative antibiotic chosen

Clinical question: does self-reported penicillin allergy — and the alternative antibiotics it triggers — affect implant surgical complications, early failure, and crestal bone loss?

Methodology: this retrospective cohort study reviewed dental records of implant patients, comparing those with self-reported penicillin allergy (exposed) to those without (unexposed), matched at roughly a 1:2 ratio. A total of 179 subjects and 374 implants were evaluated for postsurgical complications, preloading crestal bone loss (PLCBL), and early failure, using bivariate analyses and mixed-effects regression models.

Main findings: overall, early implant failure occurred in 6.1% of implants and surgical complications in 8.0%; PLCBL was observed in 32.5%. In simple bivariate comparisons, patients reporting penicillin allergy had a higher prevalence of surgical complications and implant failure than those without. But once the analysis controlled for other variables in multivariable regression, self-reported penicillin allergy itself was not an independent predictor of surgical complications, PLCBL, or early failure. What did matter was the alternative antibiotic chosen: implants where azithromycin was prescribed showed a higher rate of surgical complications, and both azithromycin and clindamycin were associated with higher early failure rates compared with penicillin. No significant association was found between antibiotic type and PLCBL.

Clinical relevance: this reframes a common perioperative decision. The allergy label itself is not the risk factor — the substitute antibiotic is. Azithromycin and clindamycin, the default alternatives for penicillin-allergic patients, appear to carry a higher burden of surgical complications and early failure than penicillin, at least in this single-center cohort. That does not mean penicillin-allergic patients should receive penicillin, but it does suggest the alternative should be chosen deliberately — amoxicillin-clavulanate desensitization protocols, cephalosporins in patients without severe/immediate-type allergy, or other options may deserve consideration over reflexive azithromycin or clindamycin prescribing, pending confirmation in larger, multicenter cohorts.