Initial erosion models.

Initial dental erosion - the very first tooth surface changes caused by short-term acidic exposures before any tissue loss is observed - has been studied using in vitro and in situ/in vivo protocols. This paper describes the events that should be considered when modelling initial erosion, the available protocols and their strengths and limitations. In vitro initial erosion models can provide relevant information about the erosive outcome. However, the published studies vary considerably regarding the erosive parameters used, and few of these studies have been validated. On the other hand, relevant in situ/in vivo studies are available that have studied the effect of salivary pellicle and preventive treatments on initial erosion, as well as the changes in salivary pH following exposure to acid solutions. Guidelines for good methodology in modelling initial erosion are proposed.