Influence of the Temperature of Extraoral Immersions in the Intraoral Cariogenicity Test Model

In an intraoral cariogenicity test model the influence of the temperature of the extraoral immersion solutions on both the demineralization of enamel and the pH drop of the plaque was studied. Ten volunteers wore the appliance for 3 weeks, except during 3 daily extraoral immersions of 15 min in a 3% sucrose solution. One side of the appliance was immersed in a solution at 37 °C, the other side in the same solution at room temperature (approximately 20 °C). The pH drop caused by plaque in situ as well as by plaque collected and suspended after the experiment was significantly faster at 37 °C. The lesions produced at this temperature were deeper and more demineralized. The rate of demineralization was almost twice as high at 37 than at 20 °C. Extraoral immersions at 37 °C are recommended to simulate in vivo conditions during immersion; in addition this procedure may shorten the experimental period.