Single site meta-analysis of 6% hydrogen peroxide whitening strip effectiveness and safety over 2 weeks
ABSTRACT This research evaluated efficacy and safety of 6% hydrogen peroxide whitening strips from a clinical trials database accumulated over a multi-year period at a single site.
The inclusive meta-analysis involved seven different randomized clinical trials at one dental school. Each study used 6% hydrogen peroxide whitening strips twice daily for 30min over a 2-week period. Common efficacy (digital images) and safety (examination and interview) methods were used across studies. Pooled subject-level data were analyzed using a general linear mixed model to determine overall response and effects of treatment duration on whitening.
The 148 treated subjects were 18-71 years old, with b* (yellowness) ranging from 12 to 22, and L* (lightness) ranging from 69 to 80. After 1-week strip use, the adjusted mean (S.E.) for Deltab* was -1.6 (0.08), differing significantly from baseline (p<0.0001). After 2 weeks, the adjusted mean (S.E.) for Deltab* was -2.3 (0.07), differing significantly from Week 1 (p<0.0001). The estimated correlation between Weeks 1 and 2 for Deltab* was 0.74. Study-to-study variation contributed less than 2% of Deltab* variability. Results were similar for DeltaL*, with Weeks 1 and 2 estimated means (S.E.) of 1.5 (0.13) and 2.0 (0.12). Occurrence of oral irritation (22%) and tooth sensitivity (20%) did not adversely affect whitening. Other side effects were unremarkable, and only 1 subject (0.7%) discontinued treatment early due to an adverse event.
The meta-analysis of multiple studies conducted at a single clinical site over several years establishes consistent, effective and safe vital bleaching with 6% hydrogen peroxide whitening strips.
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ABSTRACT: A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate efficacy and safety of 6% hydrogen peroxide whitening strip used twice daily over an extended, 6-week period. After informed consent, 40 eligible adults were randomly assigned to 6% hydrogen peroxide whitening strips (Crest Whitestrips, The Procter & Gamble Company, USA) or placebo strips without peroxide. Treatment was twice daily for 30min, and response was evaluated biweekly after initial (Week 2) and extended (Weeks 4 and 6) use. Tooth color was measured under standardized lighting conditions using digital image analysis, and safety was assessed from clinical examination and interview. Whitening was measured using data derived from digital images taken at baseline compared to post-treatment, with outcomes reported using the CIELAB color notation system. Analysis of variance and covariance were used to assess initial response, and repeated measures regression analysis was used to model color change during sustained use. Forty subjects (25-58 years old) started the study. At baseline, L* ranged from 68.0 to 76.8, a* ranged from 8.0 to 11.8, and b* ranged from 16.4 to 23.1. Groups differed significantly (p<0.001) on all color parameters at Week 2 and thereafter, favoring the 6% hydrogen peroxide strips. Week 2 adjusted means+/-SE were -2.1+/-0.2 for Deltab* and 1.9+/-0.2 for DeltaL* for the peroxide group compared to -0.3+/-0.2 for Deltab* and 0.4+/-0.2 for the placebo group. With sustained use (Weeks 2-6), the slope for the peroxide strip was estimated as -0.3 for Deltab* and +0.2 for DeltaL* per week, with both slopes differing significantly from zero (p<0.0001), while slopes for the placebo strip were not significant (p=0.22) and nearly zero. Treatment was generally well tolerated, with adverse events confined to symptoms only. Twice-daily use of 6% hydrogen peroxide whitening strips resulted in teeth becoming lighter and less yellow versus baseline and placebo during initial 2-week use, with no evidence of placebo response during sustained (Weeks 2-6) use.Journal of dentistry 01/2009; 37 Suppl 1:e51-6. DOI:10.1016/j.jdent.2009.05.009 · 2.84 Impact Factor
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ABSTRACT: The purpose of the study was to evaluate gloss and color changes of resin composites after exposure to different bleaching agents. Products used, were: Nite White ACP (10% carbamide peroxide gel), Crest Classic and Supreme Whitestrip (6.5% and 14% hydrogen peroxide strips, accordingly). A hybrid (Herculite XRV) and a nanohybrid (Premise) resin composite were exposed to the bleaching agents. Twenty-four disk-shaped specimens per composite were subjected to bleaching by each of the agents (n=8) for up to 2 weeks. Color changes using CIE-L*a*b* system (50:50% acceptability threshold: ΔE*=3.3) were recorded after 1 and 2 weeks bleaching cycles relative to baseline measurements. In addition, gloss measurements (in gloss units) were performed at the same bleaching intervals and gloss changes were calculated. All bleaching agents tested provided decrease in gloss of both composites after 2-week bleaching (p<0.05). No differences were detected among the three bleaching regimens, for up to 2-week application, in terms of color and gloss changes on both composites. After the 2-week bleaching period, hybrid composite presented higher gloss reduction (%) than nanohybrid regardless of the bleaching agent (p<0.05). Color change (ΔE*) was lower than 3.3 for all composite-bleaching agent combinations. After 1- and 2-week bleaching time, the nanohybrid composite provided higher color change than the hybrid under all bleaching procedures (p<0.05). No strong correlation was proved between color (ΔE*) and gloss changes caused by bleaching treatments. After 2-week bleaching cycles, composites showed significant gloss reduction (p<0.05). Color alteration was below the 50:50% acceptability threshold (ΔE*<3.3) and it was product-depended. There was no significant difference in color and gloss changes between the evaluated bleaching strips and 10% carbamide peroxide gel.Journal of dentistry 01/2010; 38 Suppl 2(Supplment 2):e129-36. DOI:10.1016/j.jdent.2010.06.006 · 2.84 Impact Factor
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ABSTRACT: Evidence-based medicine (EBM) employs the best available evidence in a particular time and context to solve specific clinical problems. This method of practicing medicine has been adopted by most of the disciplines involved in medical training; however, morphology appears to remain beyond this paradigm. The first step in evidence-based practice based on morphology is to recognize the types of studies being conducted with regard to morphology, followed by the assessment of the level of evidence that they provide, which is the purpose of this study. We designed a bibliometric study, in which journals in the Master Journal List of Thomson Reuters, selected using the keywords "Morphology" or "Anatomy," available between 2007 and 2008, with access to full text in electronic version, whose languages were English and Spanish, and which only considered studies on human morphology, were included. We analyzed a total of 790 articles, of which 93.1% were descriptive, 6.5% were analytical, and 0.4% were experimental design types. According to the stage of the study, most of the articles (94.8%) accounted for prevalence and differential diagnosis studies, concentrating on numerous designs such cross-section, which gave complex evidence (1c). The use of these methodologies for the systematic morphological knowledge allowed us to widen our research to generate clinically useful recommendations or merely a teaching approach based on the systematic morphological knowledge available