Type-2 diabetes (T2DM) is a global epidemic. Among various complications of T2DM, dental caries is one of its preventable complications. This investigation was aimed to study the association between salivary factors and the growth of cariogenic bacteria in the saliva of T2DM patients. We measured the salivary glucose, saliva flow rate and its buffering capacity in T2DM patients (N = 100). Cariogenic bacteria in saliva were detected by using a Chair-side Test Kit. We also analyzed fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) in all the subjects. A large number of T2DM patients (78%) had high counts (>10⁵ CFU /ml) of streptococcus mutans in their saliva whereas high counts of lactobacilli were observed only in 42% patients. We observed significant associations between streptococcus mutans load and saliva flow rate, saliva buffering capacity and glycemic control however these variable did not show any significant association with lactobacilli. Hypo-salivation, high salivary glucose and poor glycemic control promoted the growth of streptococcus mutans in the saliva of T2DM patients. In conclusion, salivary factors play important roles in controlling the salivary status of cariogenic bacteria. Thus, an adequate oral health and proper glycemic control could help in abolishing the caries risk and its complications.

2型糖尿病（T2DM）是一种全球流行病。在T2DM的各种并发症中，龋齿是其可预防的并发症之一。这项研究旨在研究唾液因子与T2DM患者唾液中龋齿细菌生长之间的关系。我们测量了T2DM患者（N = 100）的唾液葡萄糖，唾液流速及其缓冲能力。唾液中的致龋菌是通过使用“椅旁检测试剂盒”检测的。我们还分析了所有受试者的空腹血糖（FBG）和糖化血红蛋白（HbA1c）。大量T2DM患者（78％）唾液中变形链球菌的计数很高（> 10 ⁵ CFU / ml），而乳酸菌的计数很高仅在42％的患者中观察到。我们观察到变形链球菌负荷与唾液流速，唾液缓冲能力和血糖控制之间存在显着关联，但是这些变量与乳酸菌没有任何显着关联。低唾液酸，高唾液葡萄糖和不良的血糖控制促进了T2DM患者唾液中变形链球菌的生长。总之，唾液因子在控制龋齿细菌的唾液状态中起重要作用。因此，适当的口腔健康和适当的血糖控制可有助于消除龋齿风险及其并发症。