Effect of soft drinks on proximal plaque pH at normal and low salivary secretion rates.
OBJECTIVE
The aim of this study was to investigate the effect of different types of drinks on plaque pH during normal and drug-induced low salivary secretion rates.


METHODS
Three drinks were tested in 10 healthy adult subjects: 1) Coca-Cola regular, 2) Coca-Cola light, and 3) fresh orange juice. pH was measured in the maxillary incisor and premolar region with the microtouch method. The area under the pH curve (AUC) was calculated.


RESULTS
During normal salivary condition, mouth-rinsing with Coca-Cola regular resulted in a slightly more pronounced drop in pH during the first few minutes than it did with orange juice. After this initial phase, both products showed similar and relatively slow pH recovery. Coca-Cola light also resulted in low pH values during the very first minutes, but thereafter in a rapid recovery back to baseline. During dry mouth conditions, the regular Cola drink showed a large initial drop in pH, and slightly more pronounced than for orange juice. After the initial phase, both products had a similar and slow recovery back to baseline. At most time-points, AUC was significantly greater in dry conditions compared to normal conditions for Coca-Cola regular and orange juice, but not for Coca-Cola light. Coca-Cola light generally showed a significantly smaller AUC than Coca-Cola regular and orange juice.


CONCLUSIONS
The main conclusion from this study is that a low salivary secretion rate may accentuate the fall in pH in dental plaque after gentle mouth-rinsing with soft drinks.
Johansson
Ann-Katrin
AK
Department of Oral Sciences - Cariology, Faculty of Dentistry, University of Bergen, Bergen, Norway. Ann-Katrin.Johansson@odont.uib.no
Lingström
Peter
P
Birkhed
Dowen
D
D000328:Adult; D019540:Area Under Curve; D001628:Beverages; D002253:Carbonated Beverages; D032084:Citrus sinensis; D003773:Dental Plaque / Q000737:chemistry*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D012463:Saliva / Q000502:physiology*; D014987:Xerostomia / Q000503:physiopathology*