In Vitro Killing Activity of Crevicular Concentrations of Tinidazole Plus Common Oral Antibiotics Against High‐Density Mixed Inocula of Periodontal Pathogens in Strict Anaerobic Conditions

Abstract

In addition to its high activity against anaerobic periodontal pathogens, tinidazole offered synergism with other antibiotics against the large strict anaerobic subpopulation and the small facultative subpopulation of a high-density mixed inocula of odontogenic pathogens under strict anaerobic conditions, similar to those of odontogenic infections.

Comparative In Vitro Resistance of Human Periodontal Bacterial Pathogens to Tinidazole and Four Other Antibiotics

“…The present in vitro study findings show that tinidazole plus amoxicillin would provide similar broad-spectrum antimicrobial activity as metronidazole plus amoxicillin, a drug combination frequently employed in human periodontal disease treatment [19]. Tinidazole additionally has been shown to exhibit antimicrobial synergism in vitro in combination with either amoxicillin/clavulanic acid, levofloxacin, or clindamycin against a mixed bacterial inoculum of periodontal origin [32]. Pharmacokinetic studies are needed to determine the best dosing schedules for such possible combined antibiotic regimens in light of differing half-life values for tinidazole and other non-imidazole antibiotics, such as amoxicillin [27].…”

“…The breakpoint concentration values for metronidazole, amoxicillin, doxycycline, and clindamycin were employed in previous periodontal and dental implant microbiology studies [33,35], and represent drug levels at or above minimal inhibitory concentrations associated with the "susceptible" interpretative category for anaerobic bacteria as recognized by the Clinical and Laboratory Standards Institute (CLSI) [36], or the French Society for Microbiology (for doxycycline) [37]. The 16 mg/L non-susceptible breakpoint concentration for metronidazole was also used for tinidazole in this study, since breakpoint concentrations for tinidazole are not established, but are considered to be equivalent to those for metronidazole [32]. All inoculated EBBA plates were incubated at 37 • C for 7 days in a upright heated incubator (Caron, Marietta, OH, USA) in jars containing an 85% N 2 -10% H 2 -5% CO 2 anaerobic atmosphere introduced by an automatic jar evacuation-replacement system (Anoxomat Mark II, Advanced Instruments, Inc., Norwood, MA, USA).…”

“…Systemic tinidazole has shown efficacy in treatment of pericoronitis lesions and acute periodontal abscesses [28], was reported to provide a subjectively higher effective treatment rate in periodontitis patients than systemic metronidazole (73.1% versus 43.5%) [29], and in smoking periodontitis patients, induced significantly more favorable changes in probing depth, clinical periodontal attachment level, and gingival inflammation than conventional periodontal root scaling alone [30]. Only limited data are presently available on the antimicrobial effects of tinidazole on various putative human periodontal bacterial pathogens [31,32], particularly in comparison to other potential systemic periodontal antibiotic drug choices [18][19][20].…”