Effect of toothbrushing with different manual toothbrushes on the shear bond strength of orthodontic brackets

The aim of this study was to evaluate the effect of brushing with a Colgate 360° or Oral B Indicator 35 toothbrush on the shear bond strength of orthodontic brackets bonded to extracted human teeth. The bristle wear and bristle tip morphology were also examined after simulated tooth-brushing. Orthodontic brackets (Roth-P/1 st and 2 nd pre-molar S/D- Slot 0.18) were bonded (Transbond XT ®) to the smoothest surface of each of 45 extracted human molar and premolar teeth. Test specimens were randomly divided into three groups: Group 1, control group with no brushing; Group 2, brushing with the Oral B Indicator 35; Group 3, brushing with the Colgate 360°. Samples were adapted to a machine that simulated tooth-brushing. The bond strength of each bracket to each tooth was assessed with a mechanical testing machine. The bristle wear and bristle tip morphology indices were also assessed. Statistically significant differences were defined for p ≤ 0.05. The average bond strengths (range: 90.18-90.89 kgf/cm 2) did not differ among the three groups. The Colgate 360° showed less bristle wear and a better bristle tip morphology than the Oral B Indicator 35 toothbrush. However, use of either toothbrush did not decrease the bond strength of the orthodontic brackets. Therefore, patients undergoing orthodontic therapy can safely use either toothbrush.

Exigência de treonina digestível para codornas de corte no período de 15 a 35 dias de idade

The digestible threonine (DThr) requirements for meat quails (Coturnix coturnix sp) during growing phase from 15 to 35 days of age were estimated, using 1,020 quails with 15 days of age, of both sexes, distributed in a completely randomized design, with six levels of digestible threonine-0.93; 1.00; 1.07; 1.14; 1.21 and 1.28% in diet, five replications and 34 quails per experimental unit. There was no effect on performance variables, carcass yield and chemical composition and nitrogen balance with the studied increase in digestible threonine levels. There was a linear increase in threonine intake and feed cost per kilogram of body weight gain with increasing levels of digestible threonine. It was concluded that the best level of threonine evaluated was sufficient to meet the requirements of meat quails, in the period from 15 to 35.

Acta resumida de la 72a sesión celebrada en Panamá el viernes 15 de mayo de 1959 a las 10.35 horas

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Acta resumida de la 75a sesión celebrada en Panamá el sábado 16 de mayo de 1959 a las 15.35 horas

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Summary Record of the Seventy-Second Meeting Held at Panama City on Friday, 15 May 1959, at 10.35 a.m.

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Acta resumida de la 66a sesión celebrada en La Paz, el 17 de mayo de 1957 a las 15.35 horas

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Acta resumida de la 59a sesión celebrada en Bogotá, el Jueyes 1o. de septiembre de 1955 a las 15.35 horas

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Summary Record of the Fifthy-Ninth Meeting Held at Bogota on Thursday, 1 September, 1955 at 3.35 p.m.

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