Impact of oral surgery, with or without amoxicillin, on the oral microbiome, salivary flow and buffering capacity of saliva

Antibiotic prophylaxis is not usually recommended in the post-operative period due to tooth extraction operations. However, in more traditional clinical practices, the use of amoxicillin continues to represent the most influential factor in preventing bacterial infections. To evaluate the effectiveness of such an approach in the dental field, a phase IV, randomized, controlled, single-center double-masked clinical study was conducted, according to the split-mouth design. The investigation concerned only simple tooth extraction operations, in which patients were divided into two groups. Only one of the established groups was prescribed antibiotic therapy. Thus, the evolution of the oral microbiome was evaluated through the count of Streptococcus mutants and Lactobacillus, the salivary flow, and the buffering power of the saliva before and after the extraction procedure. Several units reported a significant change in bacterial load in the antibiotic-treated group, from baseline to seven days and fourteen days after surgery. In the same group, however, no substantial changes occurred in the salivary flow and the saliva’s buffering capacity. Given the high complexity of the salivary microbiome and its barrier functions for the human organism against attacks by pathogenic microbes, it is considered necessary to promote further studies aimed at investigating the mutations induced by antibiotic therapy, even if the results emerging from the most recent literature highlights the preventative role of prevention in post-extraction complications. However, given the low incidence of infections even in the absence of prevention, it becomes crucial to investigate how the risks of potential antibiotic resistance can compromise the benefits of antibiotic use.