Acclimatization of micropropagated Heliconia bihai (Heliconiaceae) plants

A cultura da helicônia é a que apresenta maior crescimento entre o cultivo de flores tropicais para a exportação. Avaliou-se o comportamento de mudas de helicônias micropropagadas no processo de aclimatização, em diferentes substratos e níveis de sombreamento. Foram plantadas mudas de H. bihai (Lobster Claw I) em bandejas plásticas contendo os diferentes substratos: areia lavada, vermiculita (textura média) e PlantMax® Horticultura. Na avaliação de níveis de sombreamento foi utilizado o telado (sombrite), com ordem de sombreamento 0% (pleno sol), 30%, 40%, 50%, 60%, 70% e 80%. O desempenho foi superior nos substratos areia lavada e PlantMax® Horticultura e nas condições de sombreamento a partir de 50 %, em especial 70% e 80%. As raízes pré-existentes, oriundas do enraizamento in vitro, mostraram-se não funcionais, sem a emissão de raízes secundárias e apresentando necrose do tecido radicular. As mudas aclimatizadas desenvolveram novas raízes, o que sugere que esta cultura pode ser aclimatizada sem que as plântulas passem pela fase de enraizamento em laboratório.To evaluate the behavior of micropropagated heliconia seedlings during the acclimatization process using different substrates and shade levels, seedlings of H. bihai (Lobster Claw I) were planted in plastic trays using the substrates: washed sand, vermiculite (medium texture), and PlantMax® Horticultura, and shade cloths with percentages of 0% (full sun), 30%, 40%, 50%, 60%, 70%, and 80% of shade in relation to full sun. Best results were obtained for washed sand and PlantMax substrates at shade conditions starting from 50%, especially at 70% and 80%. Pre-existing roots from in vitro rootings were not functional, not presenting secondary roots, and showing root tissue necrosis. Acclimatized seedlings developed new roots. This finding suggests that this plant can be acclimatized without going through a laboratory rooting stage

Effectiveness Of Dental Bleaching In Depth After Using Different Bleaching Agents.

This study evaluated the effectiveness of low- and high-concentration bleaching agents on enamel and deep dentin. Stained bovine incisors fragments were randomized placed into 10 groups (n=5), according to the sample thicknesses (2.0 mm or 3.5 mm) and bleaching agent: 10% carbamide peroxide (CP) (4 h a day/21 days); 6% hydrogen peroxide (HP) with calcium (1:30 h a day/21 days); HP 20% with calcium (50 min a day/3 sessions with a 7-day interval); HP 35% (3 x 15 min a day/3 sessions with a 7-day interval); HP 35% with calcium (40 min a day/3 sessions with a 7-day interval). The samples were stored in artificial saliva during the experiment. The color change was evaluated using a spectrophotometer at the initial analysis, after artificially staining with black tea and after each of the bleaching weeks, and data was expressed in CIE Lab System values. The L* coordinate data was submitted to analysis of variance and Tukey-Kramer test and the ?E values data was submitted for analysis of variance in a split-plot ANOVA and Tukey's test (?=0.05). None of the bleaching agents tested differed from the reflectance values on the enamel surface. For deep dentin HP 20% and HP 35%, both with calcium, showed the lowest reflectance values, which differed from CP 10%. It is concluded that high concentration hydrogen peroxide with calcium was less effective in deep dentin than 10% carbamide peroxide. Key words:Dental bleaching; hydrogen peroxide; carbamide peroxide; dental staining.5e100-

Aclimatização de mudas micropropagadas de Heliconia bihai (Heliconiaceae)

To evaluate the behavior of micropropagated heliconia seedlings during the acclimatization process using different substrates and shade levels, seedlings of H. bihai (Lobster Claw I) were planted in plastic trays using the substrates: washed sand, vermiculite (medium texture), and PlantMax® Horticultura, and shade cloths with percentages of 0% (full sun), 30%, 40%, 50%, 60%, 70%, and 80% of shade in relation to full sun. Best results were obtained for washed sand and PlantMax substrates at shade conditions starting from 50%, especially at 70% and 80%. Pre-existing roots from in vitro rootings were not functional, not presenting secondary roots, and showing root tissue necrosis. Acclimatized seedlings developed new roots. This finding suggests that this plant can be acclimatized without going through a laboratory rooting stage.A cultura da helicônia é a que apresenta maior crescimento entre o cultivo de flores tropicais para a exportação. Avaliou-se o comportamento de mudas de helicônias micropropagadas no processo de aclimatização, em diferentes substratos e níveis de sombreamento. Foram plantadas mudas de H. bihai (Lobster Claw I) em bandejas plásticas contendo os diferentes substratos: areia lavada, vermiculita (textura média) e PlantMax® Horticultura. Na avaliação de níveis de sombreamento foi utilizado o telado (sombrite), com ordem de sombreamento 0% (pleno sol), 30%, 40%, 50%, 60%, 70% e 80%. O desempenho foi superior nos substratos areia lavada e PlantMax® Horticultura e nas condições de sombreamento a partir de 50 %, em especial 70% e 80%. As raízes pré-existentes, oriundas do enraizamento in vitro, mostraram-se não funcionais, sem a emissão de raízes secundárias e apresentando necrose do tecido radicular. As mudas aclimatizadas desenvolveram novas raízes, o que sugere que esta cultura pode ser aclimatizada sem que as plântulas passem pela fase de enraizamento em laboratório.299301Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Efficacy Of Tooth Bleaching With The Prior Application Of A Desensitizing Agent.

In the present study, we evaluated the efficacy of bleaching on enamel and opposite dentin surfaces using 35% hydrogen peroxide (HP) with the prior application of a desensitizing agent. Thirty bovine dental fragments, with thicknesses of 1 mm enamel and 1.75 mm dentin, were stained in a solution of black tea. The fragments were randomly divided into three groups (n = 10) according to the following protocols: (a) 2% neutral fluoride + bleaching; (b) desensitizing agent + bleaching; and (c) without desensitizer + bleaching. The bleaching efficacy was evaluated four times: after staining with tea (baseline) and after each of the 3 weeks of bleaching, by means of the CIE Lab method using a reflectance spectrophotometer. The data coordinate L* was evaluated by an analysis of repeated measures with PROC MIXED and Tukey-Kramer's test. The ΔE values were subjected to anova and Tukey's test (α = 0.05). The 35% HP treatment showed greater efficacy on deep dentin after removal of the enamel stains, with increasing means during all times in all treatments. The use of a desensitizing agent prior to the bleaching session did not affect the mechanism of action of 35% HP with regard to tooth depth

New formula to objectively evaluate skeletal maturation using lateral cephalometric radiographs Nova fórmula para avaliação objetiva da maturação esquelética em radiografias cefalométricas laterais

The aim of this study was to establish two new formulas for objectively evaluating skeletal maturation of cervical vertebrae in female and male Brazilian subjects using lateral cephalometric radiographs. The sample included 128 girls and 110 boys, aged 7.0 to 15.9 years, from the files of the Oral Radiology Clinic, Piracicaba Dental School, University of Campinas (Unicamp), SP, Brazil. The cervical vertebral bodies of C3 and C4 were traced and measured and regression formulas were developed in order to determine cervical vertebral bone age. Another sample of lateral teleradiographs and hand-wrist radiographs of 55 girls and 54 boys (aged 7.0 to 15.9 years) was used to verify the reliability of the developed regression formulas, as compared with bone age assessed using the Tanner et al.15 (2001) Method (TW3) in hand-wrist radiographs. The analysis of both the boys’ and girls’ data (ANOVA) showed no statistical difference between cervical vertebral bone age, bone age, and chronological age, indicating that these formulas can be used in this population (p = 0.5721 and p = 0.6007 for girls and boys, respectively). Female cervical vertebral bodies of C3 and C4 increased in an accelerated manner from 10 to 13 years. Analysis of the male sample showed that C3 measurements increased in an accelerated manner from 12 to 15 years. The C4 measurements, however, did not increase at all. Using cervical vertebral bone age it is possible to evaluate skeletal maturation objectively in cephalometric radiographs.<br>O objetivo deste estudo foi estabelecer dois novos métodos para meninas e meninos brasileiros, no intuito de determinar de forma objetiva a maturação esquelética das vértebras cervicais em radiografias cefalométricas laterais. Foram selecionados 128 meninas e 110 meninos, com faixa etária variando entre 7 e 15,9 anos, pertencentes à Clínica de Radiologia da Faculdade de Odontologia de Piracicaba da Universidade de Campinas (Unicamp). Os corpos da terceira e quarta vértebras cervicais foram traçados e medidos e fórmulas de regressão foram criadas no intuito de se estabelecer a idade óssea das vértebras cervicais. Uma outra amostra composta por telerradiografias em normal lateral e radiografias carpais de 55 meninas e 54 meninos com a mesma faixa etária foi utilizada para verificar a confiabilidade das fórmulas criadas, em comparação à idade óssea determinada pelo método de Tanner et al.15 (2001) (TW3) em radiografias carpais. A análise da amostra feminina e masculina (ANOVA) revelou não haver diferença estatística significativa entre idade óssea da vértebra cervical, idade esquelética e idade cronológica, indicando que as fórmulas desenvolvidas podem ser utilizadas nesta população (p = 0,5721 e p = 0,6007 para meninas e meninos, respectivamente). Os corpos da terceira e quarta vértebras cervicais aumentaram de forma acelerada dos 10 aos 13 anos nas meninas. A análise da amostra masculina revelou aumento acelerado de C3 dos 12 aos 15 anos. A vértebra C4, no entanto, não aumentou em tamanho. Utilizando a idade óssea de vértebras cervicais, é possível avaliar a maturidade esquelética de forma objetiva em radiografias cefalométricas laterais