Effect of sugarcane chewing on plaque pH in rural Kenyan children

In 5 rural Kenyan children, the effect of sugarcane chewing on plaque pH was compared with the effect of a mouthrinse with 10% sucrose at various intraoral sites. They all had poor oral hygiene and at least two carious cavities in occlusal surfaces of molars. pH measurements were conducted under field conditions using paladium touch microelectrodes connected to a battery-operated pH meter. There was a marked difference in pH response of non-carious approximal sites between maxilla and mandible, with the lowest values in the maxilla. However, the pH recovery following the instantaneous drop occurred in parallel even if most pH values had not returned to baseline values 30 min after the sucrose rinse. Following the sugarcane chewing, the pH fall was less pronounced on all sites, and within 5-10 min the values had returned to resting pH and even exceeded this. In carious cavities, a similar pattern was observed, although the acidity in these sites was more pronounced, also reflected in a lower resting mean pH. The main conclusion from this study is that sugarcane chewing yields a less pronounced pH drop and a quicker pH recovery in dental plaque than is seen following a mouthrinse with 10% sucrose. This difference probably results from stimulation of salivary flow associated with the chewing.