Effect of intracoronal bleaching agents on dentin microhardness

Area of Science:

• Dental Materials Science
• Endodontics
• Biomaterials

Background:

• Intracoronal bleaching is a common procedure for treating discolored endodontically treated teeth.
• The use of bleaching agents can potentially compromise the structural integrity of dentin.
• Chlorhexidine (CHX) is known for its antimicrobial properties and is sometimes used in endodontic treatments.

Purpose of the Study:

• To evaluate the impact of intracoronal bleaching agents, with and without chlorhexidine gel, on dentin microhardness.
• To compare the effects of different bleaching agents (sodium perborate and carbamide peroxide) combined with chlorhexidine on dentin.
• To determine if chlorhexidine influences the microhardness reduction caused by bleaching agents.

Main Methods:

• An in vitro study involving sixty human maxillary incisor crowns.
• Teeth were divided into six groups, treated with various bleaching agents (sodium perborate, carbamide peroxide) alone or combined with 2% chlorhexidine gel, or water as a control.
• Dentin microhardness testing was performed at inner, middle, and outer dentin levels after bleaching.

Main Results:

• The sodium perborate plus 30% hydrogen peroxide group showed the greatest reduction in dentin microhardness.
• No significant difference in microhardness was found between the sodium perborate plus water group and the sodium perborate plus 2% chlorhexidine gel group.
• The addition of 2% chlorhexidine gel did not adversely affect dentin microhardness when used with the tested bleaching agents.

Conclusions:

• Intracoronal bleaching with sodium perborate and hydrogen peroxide significantly reduces dentin microhardness.
• Chlorhexidine gel, when used as an adjunct to intracoronal bleaching, does not negatively impact dentin microhardness.
• Chlorhexidine may serve as a beneficial antimicrobial agent during intracoronal bleaching procedures without compromising dentin integrity.