Effectiveness of Teeth Whitening after Regenerative Endodontics Procedures: An In Vitro Study

Area of Science:

• Endodontics
• Regenerative Dentistry
• Dental Materials Science

Background:

• Tooth discoloration is a significant concern following regenerative endodontic procedures (REPs), impacting patient quality of life.
• Minimizing discoloration risk involves careful selection of scaffolds and barrier materials.
• Whitening is a potential minimally invasive treatment for post-REP discoloration.

Purpose of the Study:

• To evaluate tooth discoloration after single- and two-visit REPs.
• To assess the effectiveness of carbamide peroxide whitening on discolored teeth post-REPs.
• To compare the staining potential of different material combinations used in REPs.

Main Methods:

• 200 bovine incisors were divided into 20 groups, including controls (saline, blood).
• Tested material combinations included triple antibiotic paste (TAP) or calcium hydroxide (CH) as intracanal medicaments, with scaffolds (blood, platelet-rich fibrin [PRF]) and barrier materials (Biodentine, OrthoMTA, MTA Repair HP).
• Procedures were performed in single- or two-visit protocols, followed by two carbamide peroxide bleaching sessions; color change (ΔE) was measured spectrophotometrically.

Main Results:

• Discoloration occurred in most groups after REPs, except for PRF + MTA Repair HP.
• All tested groups showed noticeable color change (ΔE > 3.3) after bleaching.
• No significant visual color change (ΔE < 3.3) was observed between the first and second bleaching in CH + PRF + MTA Repair HP groups.

Conclusions:

• Single-visit REPs are preferable to minimize discoloration risk.
• If two-visit REPs are necessary, calcium hydroxide is recommended over TAP due to lower staining potential.
• Platelet-rich fibrin is a suitable scaffold to minimize discoloration; whitening is beneficial but not a guaranteed solution for original color restoration.