BackgroundThis study was aimed to evaluate the changes in salivary output and its effect on dental caries among Indian troops after 6 months of stay at high-altitude area (HAA). MethodsAll troops undergo mandatory dental checkup during acclimatization phase before deployment at HAA. Two thousand troops who fulfilled inclusion and exclusion criteria were selected, and consent for the study was obtained. Stimulated and unstimulated salivary samples were collected, the decayed, missing, and filled teeth (DMFT) index was evaluated, and required dental treatment was completed. The same salivary samples were collected after 6 months (on deinduction) to evaluate the salivary output. The DMFT index was re-evaluated to check the initiation of caries. ResultsThe mean values of unstimulated and stimulated saliva at the initial visit were 4.105 and 17.03 gm, respectively, whereas the mean values of unstimulated and stimulated saliva after 180 days were 3.034 and 15.831 gm, respectively. Salivary flow was found to be significantly decreased after 6 months both in unstimulated and stimulated saliva. The mean DMFT at the time of induction of the study was 6.18 ± 3.03, and on deinduction, it was 7.22 ± 3.45 with p < 0.001, which was highly statistically significant. ConclusionA decrease in body fluids and changed sympathetic and parasympathetic at HAA lead to decreased salivary secretions. Low water intake, high carbohydrate solid diet, negligible supply of fresh food, difficulty in maintenance of oral hygiene, and overall stress due to loneliness are all contributory factors for an increase in dental caries. It clearly demonstrates that prolonged stay at HAA affects salivary volume outflow, both stimulated and unstimulated, which has a corresponding effect on new caries.