TABLE 4
FROM:
Black tea – helpful or harmful? A review of the evidence
E J Gardner, C H S Ruxton and A R Leeds
BACK TO ARTICLETable 4. Tea and dental health
| Study | Participants | Methods | Outcomes |
|---|---|---|---|
| Simpson et al. (2001) | 10 healthy subjects; 21–23 years | Tooth surface pH assessed in situ, 100 ml of tea solution (40 g tea leaves in 4 l deionised water) | Only small decreases in pH detected with high inter-subject variation. Resting pH restored within approximately 2 min. No impact of tea. |
| Lingstrom et al. (2000) | 10 healthy subjects | Crossover RCT varying number of times rinsed with tea (5 vs 10 times/day) with water as control | Rinsing with black tea infusion 10 times/day resulted in attenuated fall in pH (P<0.05 or <0.01), lower plaque index (P<0.05), higher fluoride concentrations in plaque and saliva vs water. |
| Zhang and Kashket (1998) | 15 healthy subjects | Consumption of salt crackers followed by rinse with black tea vs green tea vs tap water. Maltose release monitored | Black tea infusion significantly more effective than green tea |
| Rasheed and Haider (1998) | 40 patients with caries (28 male, 12 female), 18–45 years | Bacteria isolated from samples of dental plaque and incubated with discs impregnated with tea extracts (black and green) and three designated antibiotics | No impact of black tea extracts on any types of bacteria |
| Attin et al. (1995) | 30 healthy subjects | 3 days x-over trial rinsing with black tea vs Meridol (positive control) vs tap water (negative control) 3 times/day after meals. Plaque surface area tested. No oral hygiene during trial | Decrease in plaque surface area after rinsing with Meridol (plaque score 15%) but no difference seen with tea or water (plaque score 22–24%). Tea ineffective against plaque. |
Abbreviation: RCT, randomized controlled trial.
