Barriers to diffusion of Ledermix paste in radicular dentine

Area of Science:

• Endodontics
• Dental Pharmacology

Background:

• Understanding drug diffusion in root canals is crucial for effective endodontic treatment.
• Ledermix paste, containing corticosteroid and antibiotic components, is used in pulp space treatments.
• The role of irrigation and root structures like cementum in drug permeation needs further investigation.

Purpose of the Study:

• To evaluate the impact of two irrigation regimens on the diffusion of tracer molecules from Ledermix paste.
• To determine the effect of cementum on the permeation of corticosteroid and antibiotic tracer molecules through dentine.
• To assess the clinical relevance of smear layer and cementum in limiting drug diffusion within tooth roots.

Main Methods:

• Human single-rooted teeth were used with a single root canal.
• Two irrigation regimens were tested: 15% EDTA and 1% NaOCl versus Savlon solution.
• Tracer molecules simulating corticosteroid and antibiotic diffusion from Ledermix paste were employed.
• Mechanical removal of cementum was performed in some samples.

Main Results:

• The combination of 15% EDTA and 1% NaOCl significantly enhanced tracer molecule permeation through dentine compared to Savlon.
• Mechanical removal of cementum also led to a significant increase in tracer molecule permeation.
• Neither the smear layer nor the cementum acted as absolute barriers to diffusion.

Conclusions:

• The smear layer and cementum do not completely impede the diffusion of drugs from the pulp space.
• Optimized irrigation protocols, such as using 15% EDTA and 1% NaOCl, can improve drug delivery within the root canal system.
• Findings provide valuable insights into the dynamics of drug penetration in tooth roots, relevant for clinical endodontic practice.