Method: The study was conducted in one phase of 2 h with 10 volunteers using palatal removable appliances. The groups under study were: I- 15 min, II- 30 min, III- 1 h, IV- 2 h. Before the in situ phase bovine enamel specimens were subjected to short-term acidic exposure by immersion in citric acid 0.05 M (pH 2.5) for 15 s, resulting in surface softening without tissue loss. Than the superficial microhardness test was performed and enamel specimens were selected and randomly divided into 4 groups and 10 volunteers. The volunteers used the palatal removable appliances for 2 h and at each interval time, corresponding to the studied groups, the specimens were removed for superficial microhardness measurement. Percentage of superficial microhardness change was considered to evaluate enamel remineralization. The data were tested using ANOVA and Tukey’s test (p<0,05).
Result: The results showed no significantly differences among the four studied periods of in situ remineralization (p>0.05). However there was no total remineralization.
Conclusion: Taking into consideration the results of the present study it is concluded that there is only partial remineralisation of eroded enamel regardless the time periods of saliva remineralisation.