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Antimicrobial effect and transdentinal diffusion of new intracanal formulations containing nitrofurantoin or

Ana Rita Silva1, Elizabete Brasil Santos2, Shelon Cristina Souza Pinto2

  • 1Department of Endodontics, University of Oporto, Oporto, Portugal.

Brazilian Dental Journal
|December 18, 2014
PubMed

Insights

New intracanal medications containing doxycycline (DX) and nitrofurantoin (NIT) show antimicrobial effects against Enterococcus faecalis. However, only doxycycline effectively diffused through dentinal tubules to inhibit bacteria on the external root surface.

Area of Science:

  • Endodontics
  • Microbiology
  • Dental Materials Science

Background:

  • Enterococcus faecalis is a common pathogen in persistent endodontic infections.
  • Intracanal medications are crucial for microbial control within root canals.
  • Evaluating the efficacy and diffusion of new intracanal medicaments is essential for improving treatment outcomes.

Purpose of the Study:

  • To investigate the in vitro antimicrobial activity and diffusion capabilities of novel intracanal medications against E. faecalis.
  • To compare the performance of new formulations containing nitrofurantoin (NIT) and doxycycline hydrochloride (DX) against a placebo and chlorhexidine (CHX).

Main Methods:

  • Utilized traditional agar diffusion test (ADT) and an adapted agar diffusion method (AADM) with E. faecalis.
  • Tested placebo gel (PC), 3% NIT, 3% DX, and 2% CHX gel.
  • Assessed microbial growth inhibition zones and diffusion through dentinal tubules.

Main Results:

  • In ADT, doxycycline (DX) exhibited the largest inhibition zones, followed by chlorhexidine (CHX) and nitrofurantoin (NIT).
  • In AADM, only DX and CHX demonstrated antimicrobial effects outside the root, indicating diffusion through dentinal tubules.
  • Kruskal-Wallis test revealed statistically significant differences between the tested groups (p<0.001).

Conclusions:

  • Both new DX and NIT formulations possess antimicrobial effects against E. faecalis in vitro.
  • Doxycycline (DX) is the only tested new formulation capable of diffusing through dentinal tubules to exert antimicrobial action externally.
  • These findings suggest potential for DX as an effective intracanal medication for comprehensive E. faecalis eradication.

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