Surface and structural changes in root dentine by various chelating solutions used in regenerative endodontics

Area of Science:

• Endodontics
• Dental Materials Science
• Biomaterials

Background:

• Regenerative endodontic procedures (REPs) aim to preserve vitality and promote healing in immature teeth.
• Irrigant solutions are crucial for disinfection and debris removal during REPs.
• Understanding the impact of irrigants on dentine structure is vital for long-term treatment success.

Purpose of the Study:

• To investigate the effects of prolonged irrigation with sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA), and citric acid (CA) on human root canal dentine.
• To evaluate the impact of these irrigants on dentine's physical and chemical properties, including microhardness, flexural strength, and elemental composition.

Main Methods:

• Sixty human root dentine samples were divided into 10 groups.
• Samples were irrigated with 1.5% NaOCl, followed by varying concentrations and times of EDTA or 10% CA.
• Dentine microhardness, flexural strength, and elemental/molecular composition were analyzed using Vickers, 3-point flexural testing, FTIR, and EDS.

Main Results:

• 1.5% NaOCl irrigation alone reduced dentine collagen content but did not affect mineral content or microhardness.
• EDTA and CA significantly decreased dentine microhardness and affected inorganic content, with CA showing a more pronounced effect.
• No irrigant solution significantly decreased the overall flexural strength of the dentine specimens.

Conclusions:

• Short-term NaOCl irrigation in REPs can reduce dentine collagen.
• EDTA and CA impact dentine's inorganic components and surface microhardness.
• The tested irrigant solutions did not compromise the overall mechanical integrity of dentine specimens.