Fracture resistance of teeth submitted to several internal bleaching protocols

• Autor(a) principal: Leonardo, Renato de Toledo [UNESP]
• Data de Publicação: 2014
• Outros Autores: Kuga, Milton Carlos [UNESP], Guiotti, Flavia Angelica [UNESP], Andolfatto, Carolina [UNESP], Faria-Junior, Norberto Batista de, Campos, Edson Alves de [UNESP], Keine, Katia Cristina [UNESP], Dantas, Andrea Abi Rached [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.jaypeejournals.com/eJournals/Abstract.aspx?id=6045&AID=24&num=11; http://hdl.handle.net/11449/125888
• topic: Nanoparticles; Peroxides; Tooth bleaching

Aim: The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). Materials and methods: After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). Results: The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p < 0.05). Conclusion: All bleaching protocols reduced the fracture resistance of endodontically-treated teeth, but there were no differences between each other. Clinical significance: There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.