Purpose: Although bleaching is a very common and a relatively safe clinical procedure, there are still concerns regarding post-operative tooth sensitivity and the influence that the free radicals released during the bleaching procedures can have on the polymerization efficacy of dental adhesives and composites, as well as on the dentin endogenous enzymatic activity. Recently, a novel violet LED lamp was introduced to the market, demonstrating efficacy in bleaching when used individually as well as in combination with the hydrogen peroxide gel. Hence, the aim of the study was to investigate the influence of different bleaching procedures on the endogenous enzymatic activity of dentin, restored immediately after bleaching or after 2 weeks. Methods AND Materials: Sound human extracted molars (n=6) were cut to obtain 8 slices from each tooth as to test each bleaching group on the same dental tissue: 1) 35% hydrogen peroxide gel 4x20min (HP 35%; Opalescence Endo, Ultradent); 2) violet LED lamp 4x20min (VL; Bright Max Whitening, MMOptics); 3) hybrid technique-4x20min VL + 4x4min HP 35% (HYB); 4)no bleaching (control;CTRL). Bleached specimens were restored using a universal adhesive resin in self-etch (SE) and etch-and-rinse mode (ER) (Futurabond U, Voco) and a resin composite, immediately or after 2 weeks of storage in artificial saliva. Further, in situ zymography was performed using fluorescein-conjugated gelatin, and the enzymatic activity was measured on the confocal microscopy images using ImageJ. Data were statistically analyzed (p<0.05). Results: As presented in Figures 1 and 2, bleaching with the violet LED lamp showed the lowest dentin enzymatic activity compared to all the other groups (p<0.05). HYB technique decreased, while HP 35% treatment increased enzyme activity compared to CTRL (p<0.05). Dentin restored 2 weeks after bleaching showed lower enzyme activity than restored immediately after bleaching (p<0.05). This is evident in all groups except HP and HYB, where enzyme activity still increases after 2 weeks (p<0.05). Conclusions: In order to achieve the greatest maintenance and stability of a restoration carried out after bleaching treatment, it is preferable to use the violet LED or the Hybrid bleaching protocol, and restore teeth after a period of 14 days if necessary.
Dentinal enzymatic activity of teeth restored after novel bleaching procedures
Florenzano F.;Maravic T.;Mazzitelli C.;Josic U.;D’Alessandro Carlo;Mancuso E.;Checchi V.;Breschi L.;Mazzoni A.
2023
Abstract
Purpose: Although bleaching is a very common and a relatively safe clinical procedure, there are still concerns regarding post-operative tooth sensitivity and the influence that the free radicals released during the bleaching procedures can have on the polymerization efficacy of dental adhesives and composites, as well as on the dentin endogenous enzymatic activity. Recently, a novel violet LED lamp was introduced to the market, demonstrating efficacy in bleaching when used individually as well as in combination with the hydrogen peroxide gel. Hence, the aim of the study was to investigate the influence of different bleaching procedures on the endogenous enzymatic activity of dentin, restored immediately after bleaching or after 2 weeks. Methods AND Materials: Sound human extracted molars (n=6) were cut to obtain 8 slices from each tooth as to test each bleaching group on the same dental tissue: 1) 35% hydrogen peroxide gel 4x20min (HP 35%; Opalescence Endo, Ultradent); 2) violet LED lamp 4x20min (VL; Bright Max Whitening, MMOptics); 3) hybrid technique-4x20min VL + 4x4min HP 35% (HYB); 4)no bleaching (control;CTRL). Bleached specimens were restored using a universal adhesive resin in self-etch (SE) and etch-and-rinse mode (ER) (Futurabond U, Voco) and a resin composite, immediately or after 2 weeks of storage in artificial saliva. Further, in situ zymography was performed using fluorescein-conjugated gelatin, and the enzymatic activity was measured on the confocal microscopy images using ImageJ. Data were statistically analyzed (p<0.05). Results: As presented in Figures 1 and 2, bleaching with the violet LED lamp showed the lowest dentin enzymatic activity compared to all the other groups (p<0.05). HYB technique decreased, while HP 35% treatment increased enzyme activity compared to CTRL (p<0.05). Dentin restored 2 weeks after bleaching showed lower enzyme activity than restored immediately after bleaching (p<0.05). This is evident in all groups except HP and HYB, where enzyme activity still increases after 2 weeks (p<0.05). Conclusions: In order to achieve the greatest maintenance and stability of a restoration carried out after bleaching treatment, it is preferable to use the violet LED or the Hybrid bleaching protocol, and restore teeth after a period of 14 days if necessary.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
