Effectiveness of different carbamide peroxide concentrations used for tooth bleaching: an in vitro study

OBJECTIVES: This in vitro study evaluated the effectiveness of three carbamide peroxide concentrations used for tooth bleaching treatments. MATERIAL AND METHODS: Sixty bovine dental slabs (6x6x3 mm) were obtained, sequentially polished, submitted to artificial staining (baseline) and randomized into four groups (n=15), according to the bleaching agent concentration: distilled water (control), 10% (CP10), 16% (CP16) or 37% (CP37) carbamide peroxide. CP10 and CP16 were covered with 0.2 mL of the respective bleaching gels, which were applied on enamel surface for 4 h/day during two weeks. Samples of CP37 were covered with 0.2 mL of the bleaching gel for 20 min. The gel was light activated by two 40-s applications spaced by 10-min intervals. The gel was renewed and applied 3 times per clinical session. This cycle was repeated at 3 sessions with 5 days of interval between them. Tooth shade evaluations were done with a digital spectrophotometer at T0 (baseline), T1 (after 1-week of treatment) and T2 (1-week post-bleaching). Tooth shade means were statistically analyzed by Kruskal-Wallis and Friedman's tests and color parameters were analyzed by two-way ANOVA and Tukey's test (p<0.05). RESULTS: At T1 and T2 evaluations, tooth shade was significantly lighter than at baseline for all treatment groups, considering the color parameters &#916;L*, &#916;a*, &#916;b*, &#916;E* (p<0.001) or tooth shade means (p<0.001). CP37 group showed lower shade mean change than CP10 and CP16 at T1 (p<0.01), but this difference was not statistically significant at T2 (p&gt;0.05). CONCLUSIONS: One week after the end of the treatment, all carbamide peroxide concentrations tested produced similar tooth color improvement

Projeto "Gaspar Vianna"

Alguns documentos não foram migrados por conter informações pessoais e informações de caráter confidenciais em relação ao projeto.BR IEC JMS AP UFPA AP 001DossiêItensDossiê do Projeto desenvolvido pelo Dr. José Maria de Souza via Núcleo de Patologia Regional e Higiene da UFPA mediante convênio com a Eletronorte e a Fundação de Amparo a Desenvolvimento da Pesquisa (FADESP) denominado "Gaspar Vianna". O referido projeto tem como objetivo o estudo de formas de tratamento de malária nas áreas de influência das hidrelétricas construídas e em construção na Amazônia. Estiveram envolvidos discentes bolsistas, colaboradores e estagiários. O projeto abarcava diversos subprojetos

Numbers of ORFs identified in <i>A. deanei</i> and <i>S. culicis</i> and their symbionts, according to the mechanisms of DNA replication and repair, signal transduction, transcription and translation.

<p>Numbers of ORFs identified in <i>A. deanei</i> and <i>S. culicis</i> and their symbionts, according to the mechanisms of DNA replication and repair, signal transduction, transcription and translation.</p

Members of the Fts family and PBPs that are present in endosymbionts of <i>A. deanei</i> and <i>S. culicis</i>.

<p>nd: not determined.</p

Protein Reference Sequence-Guided Assembly data of <i>A. deanei</i> and <i>S. culicis</i> genomes.

<p>Protein Reference Sequence-Guided Assembly data of <i>A. deanei</i> and <i>S. culicis</i> genomes.</p

Phylogenetic of histones of <i>A. deanei, S. culicis,</i> and other trypanosomatids.

<p>Histone protein (panel A) and nucleotide (panel B) sequences were generated by MUSCLE tool using 10 iterations in the Geneious package <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060209#pone.0060209-Drummond1" target="_blank">[120]</a>. Trees were constructed using the Geneious Tree Builder, by employing Jukes-Cantor genetic distance model with a neighbor-joining method and no out-groups. The consensus trees were generated from 100 bootstrap replicates of all detected histone genes, as shown below. Scale bars are indicated for each consensus tree. The trees in panel A are based in a collection of sequences of all trypanosomatids. The nucleotide sequences used for dihydrofolate reductase-thymidylate synthase are: <i>T. cruzi,</i> XM_810234; <i>T. brucei</i>, XM_841078; <i>T. vivax,</i> HE573023; <i>L. mexicana</i>, FR799559; <i>L. major</i>, XM_001680805; <i>L. infantum</i>, XM_001680805; and <i>C. fasciculata</i>, M22852.</p

Purine production, acquisition, and utilization in <i>A. deanei</i> and <i>S. culicis.</i>

<p>The figure illustrates the production, acquisition and utilization of purines in the host trypanosomes considering the presence of endosymbiont enzymes. This model suggests that the trypanosomatid acquires purines from the symbiont, which synthesizes them <i>de novo</i>. Some ecto-localized proteins, such as apyrase (APY) and adenosine deaminase (ADA), could be responsible for the generation of extracellular nucleosides, nucleobases, and purines. Nucleobases and purines could be acquired by the parasite through membrane transporters (T) or diffusion and could be incorporated into DNA, RNA, and kDNA molecules after “purine salvage pathway” processing. Abbreviations: NTP (nucleoside tri-phosphate), NDP (nucleoside di-phosphate), NMP (nucleoside mono- phosphate), N (nucleobase), ADO (adenosine), INO (inosine).</p

Oxidative stress-related genes in the genomes of <i>A. deanei</i>, <i>S. culicis</i> and <i>L. major</i>.

<p>The figure shows the number of ORFs for the indicated enzymes for each species.</p