Tooth enamel, vulnerable to various harmful factors, often undergoes demineralization. Combating enamel destruction typically involves replenishing demineralized areas with non-native calcium sources, which poses challenges for effective remineralization. Aspartic acid (Asp) can participate in the crystallization process of hydroxyapatite, improving its structural order and thereby helping to restore and strengthen enamel. The aim of the investigations was to determine the effect of Asp on the remineralization of a bovine enamel block in vitro. Enamel blocks were sectioned from bovine teeth, and the baseline surface microhardness (SMHR) of the samples was measured. After demineralization in a solution at pH 4.5 for 60 minutes, SMHR was remeasured. Ten enamel samples per group were treated with respective solutions for 16 hours at pH 6.5. The percentage of SMHR achieved through the treatments was calculated and used to compare the ability to repair demineralized enamel samples. Three investigations with the same design were conducted. The initial experiment indicated that 1% hydroxyapatite facilitated enamel remineralization, achieving a significant mean increase in surface microhardness (22.99±10.43; p<0.05) compared with that of the negative control, deionized water, which showed a mean decrease (-1.87±17.11; p<0.05). However, this remineralization was not superior to that induced by the fluoride positive control (35.56±23.41; p<0.05). Subsequently, the second experiment established that 0.5% aspartic acid significantly reduced enamel microhardness (-37.32±24.64; p<0.05), indicating a pronounced demineralizing effect when compared with both deionized water (-17.52±23.54; p<0.05) and fluoride (14.12±13.40; p<0.05). The third experiment demonstrated that the combination of 0.5% aspartic acid with 1% hydroxyapatite significantly enhanced remineralization (33.08±14.84; p<0.05), outperforming the fluoride-positive control (5.15±4.84; p<0.05) as well as deionized water (-29.21±18.38; p<0.05). In conclusion, while aspartic acid alone may lead to enamel demineralization, its combination with hydroxyapatite shows promise in surpassing fluoride's remineralizing efficacy, highlighting a potential synergistic approach for dental treatments.