Abstract
ObjectiveThis study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP).MethodologyA total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%).ResultsLED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times.ConclusionsViolet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.
Highlights
This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP)
Light activation of bleaching is a topic under constant discussion since a previous systematic review reported that light does not affect color change for highconcentrated hydrogen peroxide (HP) bleaching, but inconclusive results have been obtained for lower HP concentrations
All patients (n=18) submitted to the intervention were evaluated for the primary outcome and for the secondary outcomes (TS and enamel mineral content)
Summary
Tooth bleaching is a common procedure in the office routine as aesthetic appeal is a permanent trend among patients. Even though in-office bleaching gels are applied on tooth surface in a shorter period of time in comparison to those of at-home therapy, a number of studies have attested the efficacy of inoffice bleaching over the past decades. light activation of bleaching is a topic under constant discussion since a previous systematic review reported that light does not affect color change for highconcentrated hydrogen peroxide (HP) bleaching, but inconclusive results have been obtained for lower HP concentrations. Maran, et al. (2017) stated that light did not enhance the efficacy of inoffice bleaching regardless of the concentration of HP.The impact of light activation on the adverse effects caused by tooth bleaching has been investigated. Light activation does not increase tooth sensitivity (TS) when high-concentrated hydrogen peroxide gel is used, and the concentration of peroxide itself does not seem to affect the prevalence and intensity of TS. a recent randomized clinical trial introduced 37% carbamide peroxide (CP) without light as a feasible alternative to reduce TS promoted by bleaching. light activation does not modify the enamel morphology nor exacerbate in vitro mineral changes, it does not decrease calcium (Ca) and phosphorous (P) content nor increases surface roughness. Even though the concentrations of Ca and P are clinically maintained after at-home and inoffice bleaching, there is no in vivo data on the effect of light-assisted in-office bleaching on the enamel mineral content. Even though in-office bleaching gels are applied on tooth surface in a shorter period of time in comparison to those of at-home therapy, a number of studies have attested the efficacy of inoffice bleaching over the past decades.. Light activation does not increase tooth sensitivity (TS) when high-concentrated hydrogen peroxide gel is used, and the concentration of peroxide itself does not seem to affect the prevalence and intensity of TS.. Light activation does not modify the enamel morphology nor exacerbate in vitro mineral changes, it does not decrease calcium (Ca) and phosphorous (P) content nor increases surface roughness.. Even though the concentrations of Ca and P are clinically maintained after at-home and inoffice bleaching, there is no in vivo data on the effect of light-assisted in-office bleaching on the enamel mineral content
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