A comparison of different kinds of European chocolates on human plaque pH

To investigate the acidogenic response of plaque with various European chocolates of varying cocoa contents.

14 subjects participated in the study. On each test day plaque pH measurements were taken at baseline and at 2, 5, 10, 15, 20 and 30 minutes after challenge with the test chocolates or control foods. A plaque sample was removed from the buccal surfaces of posterior teeth representing all quadrants, within 30 seconds. The plaque pH was measured on an ISFET electrode connected to a Sentron 2001 pH system. The test chocolates were: Diet chocolate (DC), Plain European chocolate (PEC 70% cocoa), Plain English chocolate (PenC 34% cocoa), Milk English chocolate (MenC 20% cocoa), Milk European chocolate (MEC 30% cocoa), White chocolate (WC no cocoa), Milk chocolate with hazelnuts (MHC 20% cocoa). 15 g of each chocolate was consumed by the volunteers and 10 ml of 10% sucrose and sorbitol solutions were included as controls.

The data were analysed for: minimum pH, area below baseline, area below "critical pH", time spent below "critical pH" and Acidogenic Potential Index (API). DC was found to be significantly different to sucrose and all the other test chocolates, and similar to sorbitol for all the parameters studied. The area below baseline plaque pH was also significantly smaller for PEC (p<0.006) and MHC (p<0.028) as compared with sucrose. The mean area below the "critical pH" (5.7) for PEC and MHC was lower at 0.20-/+0.34 and 0.60-/+1.40 respectively, compared with sucrose at 1.38-/+1.03, but not statistically significant. The API of DC, PEC, PEnC, MEnC, MEC, WC and MHC was 0.03, 0.41, 0.66, 0.93, 0.94, 0.88 and 0.45 respectively compared with an API of 1.00 of sucrose.

Diet chocolate was found to have no acidogenic effect on dental plaque. Also, the PEC and MHC had a lower acidogenic potential compared with sucrose.