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Effect of toothpaste abrasiveness on friction and wear of dental fillings
Formánková, Pavla ; Čípek, Pavel (referee) ; Vrbka, Martin (advisor)
This bachelor thesis dealt with research, that links dental hygiene issues with tribology. The aim of the thesis was to analyze the effect of abrasive particles of toothpastes on friction and wear of dental fillings. The friction coefficient was evaluated in a tooth brushing simulation on an UMT TriboLab tribometer that lasted 260 minutes. The tribological system consisted of a toothbrush, a sample of composite material and a solution of artificial saliva with a selected toothpaste. Each paste was defined by an RDA value from 0 to 250, expressing the degree of abrasiveness therefore the ability of the toothpastes to wear the material. Wear was analysed on a Bruker Contour GT-X optical profilometer. From the measured values it was found that the influence of abrasive particles is significant in terms of wear of dental fillings. For both the friction coefficient and the material loss when measured only in the presence of artificial saliva, the resulting values were generally lower. However, the material loss in the toothpastes measurments did not increase linearly with the RDA value as expected. Literature studies and measurements have shown that this may be due to other factors affecting wear. Future research on these factors could lead to the selection of more gentle toothpastes in dentistry and thus prevent the increase in wear of dental fillings
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Determination of physico-chemical stability of toothpastes
Posztósová, Gyöngyi ; Vítová, Eva (referee) ; Němcová, Andrea (advisor)
This diploma thesis is focused on determining the physico-chemical stability of toothpastes. It is divided into theoretical and practical part. The theoretical part of the work deals with toothpastes, their short history and composition. Stability studies and methods of stability analysis are described below. In the practical part were performed long-term and accelerated stability studies on anhydrous toothpastes, on water-based toothpastes and on toothpastes based on sodium bicarbonate. The physical stability of the products was evaluated by monitoring the appearance and color visually and odor sensory, the pH value using a pH meter and the viscosity with a rotational viscometer. Chemical stability was monitored by determining the free fluorine content by ion chromatography and by ion-selective electrode, total phosphates and potassium also by ion chromatography, sodium bicarbonate by titration, soluble zinc by atomic absorption spectrometry and water activity was also monitored.
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Effect of toothpaste abrasiveness on friction and wear of dental fillings
Formánková, Pavla ; Čípek, Pavel (referee) ; Vrbka, Martin (advisor)
This bachelor thesis dealt with research, that links dental hygiene issues with tribology. The aim of the thesis was to analyze the effect of abrasive particles of toothpastes on friction and wear of dental fillings. The friction coefficient was evaluated in a tooth brushing simulation on an UMT TriboLab tribometer that lasted 260 minutes. The tribological system consisted of a toothbrush, a sample of composite material and a solution of artificial saliva with a selected toothpaste. Each paste was defined by an RDA value from 0 to 250, expressing the degree of abrasiveness therefore the ability of the toothpastes to wear the material. Wear was analysed on a Bruker Contour GT-X optical profilometer. From the measured values it was found that the influence of abrasive particles is significant in terms of wear of dental fillings. For both the friction coefficient and the material loss when measured only in the presence of artificial saliva, the resulting values were generally lower. However, the material loss in the toothpastes measurments did not increase linearly with the RDA value as expected. Literature studies and measurements have shown that this may be due to other factors affecting wear. Future research on these factors could lead to the selection of more gentle toothpastes in dentistry and thus prevent the increase in wear of dental fillings
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|
|
Determination of physico-chemical stability of toothpastes
Posztósová, Gyöngyi ; Vítová, Eva (referee) ; Němcová, Andrea (advisor)
This diploma thesis is focused on determining the physico-chemical stability of toothpastes. It is divided into theoretical and practical part. The theoretical part of the work deals with toothpastes, their short history and composition. Stability studies and methods of stability analysis are described below. In the practical part were performed long-term and accelerated stability studies on anhydrous toothpastes, on water-based toothpastes and on toothpastes based on sodium bicarbonate. The physical stability of the products was evaluated by monitoring the appearance and color visually and odor sensory, the pH value using a pH meter and the viscosity with a rotational viscometer. Chemical stability was monitored by determining the free fluorine content by ion chromatography and by ion-selective electrode, total phosphates and potassium also by ion chromatography, sodium bicarbonate by titration, soluble zinc by atomic absorption spectrometry and water activity was also monitored.
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