Changes in saliva characteristics and carious status related to metabolic control in patients with type 2 diabetes mellitus

Objectives: This cross-sectional study aimed: 1) to compare the saliva characteristics and the occurrence of caries in patients with type 2 diabetes mellitus (T2DM) and patients without T2DM, 2) to study the impact of inadequate glycemic control on saliva and caries prevalence. Methods: 23 adults with T2DM and 18 controls participated. Patients with T2DM were divided depending on their metabolic control: a) well-controlled (W.C.): HbA1c?7 %, and b) poorly-controlled (P.C.): HbA1c> 7 %). The examined clinical parameters were: 1) number of natural teeth, 2) DMFT index of coronal caries, 3) saliva pH, 4) saliva flow and buffering capacity, and 5) subjective feeling of dry mouth. Results: The groups W.C and P.C showed significant differences in the number of teeth, the saliva flow, and DMFT. The C and P.C groups presented differences in pH, saliva flow, buffer capacity, and DMFT. Finally, the W. C and C groups indicated differences in the buffer capacity, saliva flow, and DMFT. The subjective feeling of dry mouth is related to the duration of the disease. The DMFT value correlated negatively with the status of metabolic regulation. Multiple linear regression revealed that the DMFT value was positively associated with serum HbA1c levels. Conclusions: 1) Adults with T2DM present a lower saliva flow rate and buffering capacity, as well as higher caries prevalence than controls; 2) The metabolic control of T2DM is essential for the maintenance of saliva flow rate and buffering capacity, and caries prevalence; 3) The duration of T2DM is of importance for the subjective sense of dry mouth. Clinical significance: The duration and metabolic control of T2DM are important clinical parameters for oral complications. Awareness and co-operation of diabetologists and dentists are needed to detect oral lesions in patients with diabetes and be treated timely and effectively.