13860
document
Investigation of erosion and abrasion on enamel and dentine : a model in situ using toothpastes of different abrasivity . BACKGROUND Studies in vitro suggest that abrasion and erosion may act synergistically to produce wear of enamel and dentine . Methods in situ are recently available to study separately erosion and abrasion of dental tissues . The aim of this study was to combine two in situ protocols to study the interplay between erosion and abrasion of enamel and dentine . METHOD The study was a single-blind , randomised , five-treatment cross-over design involving 15 healthy volunteers . During each 10-day study period , subjects wore from 0900 to 1700 h an upper removable acrylic appliance holding one polished enamel and one polished dentine specimen . The specimen treatment regimens were : 1 . Drinking water and brushing with toothpaste A . 2 . Drinking water and brushing with toothpaste B . 3 . Drinking orange juice . 4 . Drinking orange juice and brushing with toothpaste A . 5 . Drinking orange juice and brushing with toothpaste B . Drinking and brushing times were around 0900 , 1100 , 1300 and 1500 h. Drinks were consumed as 250 ml over 10 min and brushing ex vivo for 1 min to each specimen . Measurement of tissue loss was made on days 5 and 10 of each period using a profilometer . RESULTS All treatments produced increasing tissue loss over time , which was considerably greater for dentine than enamel . For enamel , the data at days 5 and 10 showed a significant effect for erosion ( i.e . orange juice was significantly more erosive than water ) , but no significant effect for abrasion ( i.e . no significant difference between the two toothpaste treatments ) . The combined orange juice and toothpaste effects were directional for synergy but did not reach significance . For dentine at day 10 , many specimens exceeded the 50 microm set limit of the profilometer and only day 5 data were considered . There were significant effects for erosion ( orange juice produced significantly more erosion than water ) and for abrasion ( paste A was significantly more abrasive to dentine than paste B ) . The synergy effect could not be examined for dentine due to the truncation effect as the set limit of the profilometer was exceeded . CONCLUSIONS Erosion increases the susceptibility of enamel to toothpaste abrasion . Dentine is considerably more susceptible than enamel to erosion and abrasion alone or combined . Dentine loss appears to correlate with toothpaste abrasivity ( RDA value ) .
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Intervention_Physical
toothpastes
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Intervention_Physical
abrasivity
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Intervention_Physical
upper removable acrylic appliance holding one polished enamel
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Intervention_Physical
one polished dentine specimen
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Intervention_Physical
Drinking water
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Intervention_Physical
brushing
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Intervention_Physical
toothpaste
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Intervention_Physical
orange juice
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Intervention_Physical
orange juice
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Intervention_Physical
brushing with toothpaste
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Outcome_Physical
erosion
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Outcome_Physical
abrasion
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Outcome_Physical
enamel and dentine
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Outcome_Physical
abrasion
13875
Outcome_Physical
erosion
13876
Outcome_Physical
wear of enamel and dentine
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Outcome_Physical
erosion
13878
Outcome_Physical
abrasion
13879
Outcome_Physical
dental tissues
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Outcome_Physical
erosion
13881
Outcome_Physical
abrasion
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Outcome_Physical
enamel
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Outcome_Physical
dentine
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Outcome_Physical
tissue loss
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Outcome_Physical
tissue loss over time
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Outcome_Physical
erosion
13887
Outcome_Physical
abrasion
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Outcome_Physical
erosion
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Outcome_Physical
abrasion
13890
Outcome_Physical
synergy effect
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Outcome_Physical
susceptibility of enamel
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Outcome_Physical
toothpaste abrasion
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Outcome_Physical
erosion
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Outcome_Physical
abrasion
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Outcome_Physical
Dentine loss
13896
Participant_Sample-size
15