A new method for the quantitative analysis of endodontic microleakage

Area of Science:

• Endodontics
• Dental Materials Science
• Biomaterials

Background:

• Effective apical sealing is crucial for root canal treatment success.
• Commonly used sealants include Sealapex, AH Plus (Topseal), and Sealite.
• Evaluating sealant performance requires reliable leakage assessment methods.

Purpose of the Study:

• To quantitatively assess the apical seal provided by Sealapex, AH Plus (Topseal), and Sealite.
• To introduce and validate a new method using 125I-radiolabeled lysozyme penetration for leakage analysis.
• To compare the long-term sealing efficacy of the three root canal sealants.

Main Methods:

• An in vitro study involving 113 instrumented teeth with straight single root canals.
• Teeth were obturated with laterally condensed gutta-percha and one of the three test cements.
• Leakage was quantified by measuring 125I-lysozyme penetration over 28 days using gamma counting.
• Negative and positive controls were included to validate the methodology.

Main Results:

• The positive control group exhibited high leakage, while the negative control showed negligible penetration.
• Sealapex and AH Plus (Topseal) demonstrated comparable and low leakage throughout the study period, with AH Plus (Topseal) performing slightly better.
• Sealite exhibited acceptable leakage up to 14 days, followed by a significant increase, suggesting potential instability.

Conclusions:

• AH Plus (Topseal) and Sealapex provide effective long-term apical sealing in root canal treatments.
• Sealite may be less suitable for long-term applications due to potential three-dimensional instability and increased leakage.
• The 125I-radiolabeled lysozyme penetration assay is a sensitive and quantitative method for evaluating root canal sealants.