The protective effects of toothpaste against erosion by orange juice: studies in situ and in vitro.

OBJECTIVES There has been a monumental increase in the consumption of soft drinks, fruit juices and sport drinks in the UK, the US, and many other countries. Previous investigations have demonstrated the erosive nature of these acidic soft drinks. The aim of this investigation was to determine the protective effects of an experimental fluoride-based toothpaste, containing sodium hexametaphosphate, against an erosive challenge on tooth enamel. METHODS The erosion of enamel by orange juice compared the experimental toothpaste with a benchmark sodium fluoride paste and negative control, water, in a 15-day in situ model; and the same in an in vitro enamel erosion model. Flat, polished human enamel samples with a surface profile of +/-0.1mum, were exposed to the three regimens in the single blind, crossover clinical study mimicked in vitro. Depths of the resulting eroded areas were measured using a profilometer. RESULTS There was significantly more erosive damage on the specimens exposed to the benchmark paste and water compared to the test paste in both the in situ and in vitro studies. CONCLUSIONS The data provide further support for tooth brushing before meals. Results of this study further suggest the sodium hexametaphosphate containing paste could be used to provide significant erosion protection in susceptible individuals over that provided by conventional fluoride products.