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1.
Chin J Dent Res ; 24(3): 159-166, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34491010

RESUMO

OBJECTIVE: To evaluate adhesives' enamel bonding performance utilising the traditional microtensile bond strength test (µTBST) and a new double-sided microtensile bond strength test (DµTBST) to assess the suitability of the latter. METHODS: A 'tug-of-war' direct encounter design was employed to compare the enamel bond strengths of two universal adhesives and their different application modes simultaneously under the same tensile load applied to double-sided bonded specimens. Clearfil Universal Bond (CU; Kuraray, Kurashiki, Japan) and Scotchbond Universal Adhesive (SB; 3M ESPE, St Paul, MN, USA) were applied in self-etch (S) and etch-and-rinse (E) mode on 110 human molar samples to perform two experiments. Experiment 1 compared the enamel bond strengths of the combinations of adhesive application modes utilising µTBST. The data were analysed using a Welch analysis of variance (ANOVA), followed by a Games-Howell test. Experiment 2 employed DµTBST to determine the suitability of the new double-sided bonded assembly and ascertain which of the adhesive application mode combinations was superior. The data were analysed using a Kaplan-Meier survival analysis, followed by pairwise comparisons with a Mantel-Cox log-rank test. The level of significance was set at P ˂ 0.05. RESULTS: The µTBST results did not show significant differences for CUE vs CUS, SBE vs SBS, CUS vs SBS and CUS vs SBE (P ˃ 0.05); however, from DµTBST, the survival distributions for the interventions were statistically significantly different (χ2(3) = 145.130, P ˂ 0.0005), indicating the superiority of universal adhesive CU over SB and application mode E over S with certainty. CONCLUSION: DµTBST was able to add more discerning outcomes to the µTBST results, indicating that the new technique could become a valuable adjunct to the conventional method.


Assuntos
Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Resinas Compostas , Cimentos Dentários , Esmalte Dentário , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
2.
J Pharmacol Toxicol Methods ; 55(3): 248-53, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17141531

RESUMO

INTRODUCTION: The cynomolgus monkey, one of a number of primate species phylogenetically close to humans, is commonly used in cardiovascular research, but a method for determination of the RR interval-corrected QT interval in this species needs greater consideration. The objectives of this study were to determine a method for evaluating QT interval in cynomolgus monkeys individually, disregarding RR interval change artifacts, and to investigate prerequisite information for this method. METHODS: The physiological QT-RR relationship for practical evaluation of QT interval was recorded and analyzed by 24-hour telemetric ECG monitoring. A linear model for log-transformed QT and RR intervals was used to correct the QT interval from RR interval change artifacts for each animal. Sample size was also estimated based on the simulation results. RESULTS: Histograms showed that both QT and RR intervals had a right-heavy tail distribution. QT interval corrected individually by the linear model formula showed smaller within-animal variability than QTb and QTf, which were corrected by Bazett's formula and Fridericia's formula. The simulation results showed that the individual correction factor, beta(i), could be reliably estimated when at least 24 pairs of QT-RR baseline data were available. DISCUSSION: As with humans, QT interval in cynomolgus monkeys varies widely between individuals. Therefore, a method for correcting QT interval individually should be considered, whenever extensive untreated data are available.


Assuntos
Eletrocardiografia/veterinária , Frequência Cardíaca , Animais , Interpretação Estatística de Dados , Modelos Lineares , Síndrome do QT Longo/veterinária , Macaca fascicularis , Masculino , Modelos Animais , Especificidade da Espécie , Telemetria
3.
Int J Toxicol ; 24(5): 377-85, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16257857

RESUMO

Cynomolgus monkeys, one of a number of primates phylogenetically close to humans, are commonly used in animal studies. The purpose of this study was to assess biological variations in hematological and serum biochemical parameters in cynomolgus monkeys. Summary statistics and reference intervals were calculated using data from 95 male and 95 female Chinese-bred cynomolgus monkeys aged 3 to 7 years showing no abnormalities during the breeding period. Within- and between-animal variations were estimated using a random-effect analysis of variance (ANOVA), then, a simple method that applies prior information was proposed to estimate individual reference intervals. Parameters including MCV, MCH, PT, ALP, total cholesterol, and creatinine appeared to show a large between-animal variation; thus, it is considered that individual reference intervals for these parameters would be relatively small in comparison with overall reference intervals.


Assuntos
Análise Química do Sangue/veterinária , Testes Hematológicos/veterinária , Macaca fascicularis/sangue , Fatores Etários , Análise de Variância , Animais , Feminino , Masculino , Valores de Referência , Fatores de Tempo
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