Abstract: Background: Antibiotic resistance poses a major challenge in the control of bacterial infections, including chronic periodontitis. This study aimed to evaluate the antibiotic resistance of Porphyromonas gingivalis to commonly prescribed antibiotics, amoxicillin, amoxicillin–clavulanic acid, and metronidazole, in gingival crevicular fluid (GCF) samples obtained from patients with chronic periodontitis, with and without prior antibiotic exposure. Materials and Methods: This study included 24 patients diagnosed with chronic periodontitis, divided into two groups: Group 1 comprised 12 patients with a history of antibiotic exposure within the preceding 6 months and Group 2 comprised 12 patients without any prior antibiotic exposure. GCF samples were collected using sterile absorbent paper points and cultured under anaerobic conditions for the isolation of P . gingivalis . Antibiotic sensitivity was assessed by measuring the zone of inhibition (ZOI) on nutrient agar plates. The data were analyzed using the Mann–Whitney U -test, and statistical significance was set at P < 0.05. Results: Patients without prior antibiotic exposure demonstrated a slightly higher mean ZOI (17.66 mm) compared to patients with prior antibiotic exposure (16.66 mm), suggesting marginally better antibiotic effectiveness in the former group. However, this difference was not statistically significant ( P = 0.663). Conclusion: The findings indicate a reduced antibiotic effectiveness in patients with previous antibiotic exposure. These results underscore the importance of avoiding empirical antibiotic use and support the consideration of narrow-spectrum antibiotics or alternative treatment approaches, such as local drug delivery systems, to mitigate the development of antibiotic resistance.
Joe et al. (Sat,) studied this question.