Combined catalytic strategies applied to in-office tooth bleaching: whitening efficacy, cytotoxicity, and gene expression of human dental pulp cells in a 3D culture model

Author(s)

Ribeiro, Rafael Antonio de Oliveira ; Peruchi, Victoria ; Sores, Igor Paulino Mendes ; Mon, Filipe Koon Wu ; Soares, Diana Gabriela ; Hebling, Josimeri ; Costa, Carlos Alberto de Souza

• Document type: Journal article
• Source: CLINICAL ORAL INVESTIGATIONS; v. 28, n. 12, p. 13-pg., 2024-11-29.

Abstract

Objectives To evaluate the feasibility of using a 3D model with human dental pulp cells (HDPCs) to compare bleaching therapies and assess whether coating enamel with a nanofiber scaffold (NS) and polymeric catalyst primer (PCP), combined with violet LED (LEDv) irradiation, enhances bleaching efficacy (BE) and reduces cytotoxicity (CT). Materials and methods After using NS + PCP to cover enamel of enamel/dentin discs adapted to artificial pulp chambers containing 3D culture with HDPCs, a bleaching gel with 35%H2O2 was applied and then irradiated with LEDv. The following groups were established (n = 8): NC - no treatment; PC- 35%H2O2 for 45 min, and EXP: NS + PCP + 35%H2O2 + LEDv for 15 min. The study evaluated BE (Delta E-00 and Delta WID), CT (alamarBlue), and HDPCs gene modulation (TNF, IL1B, PTGS2, IL8, IL6, PPRAG, HMOX1, DSPP, DMP1, SPP1, BGLAP, and ALPL; RTqPCR). Results BE showed no significant difference between PC and EXP (p > 0.05). EXP had lower oxidative stress, higher cell viability, reduced inflammatory marker expression, and increased mineralization marker expression compared to PC (p < 0.05). Conclusion The 3D model using HDPCs effectively compared bleaching protocols. Coating enamel with NS + PCP and applying violet LED (LEDv) reduced bleaching time from 45 to 15 min while lowering cytotoxicity compared to conventional in-office treatments. Clinical relevance This study shows that a 3D model with human dental pulp cells (HDPCs) effectively compares tooth bleaching protocols. The combination of a nanofiber scaffold with violet LED (LEDv) reduces bleaching time, as well as minimizes cytotoxicity and inflammation, offering a safer alternative to conventional treatments. (AU)

• FAPESP's process: 23/02780-5 - Development and application of a TiF4-loaded polymeric primer for in-office dental bleaching associated with violet LED irradiation
• Grantee: Carlos Alberto de Souza Costa
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/01184-4 - Development of an innovative strategy for in-office tooth bleaching: aesthetic effectivity and biocompatibility associated with reduced clinical time
• Grantee: Rafael Antonio de Oliveira Ribeiro
• Support Opportunities: Scholarships in Brazil - Doctorate