Sepideh Najafi - Department of Oral and Maxillofacial Medicine, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
Maryam Mardani - Oral and Dental Disease Research Center, Department of Oral and Maxillofacial Medicine, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
Mohammad Motamedifar - Department of Medical Microbiology, Shiraz HIV/AIDS Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran
Mohammad Ali Nazarinia - Department of Internal Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Mahtab Hadadi - Department of Bacteriology and Virology, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran

Background and Objective: Systemic sclerosis is an autoimmune disorder with orofacial manifestations, including tooth decay. Lactobacilli can inhibit biofilm formation and growth of cariogenic pathogens, such as Streptococcus mutans. We aimed to assess the salivary levels of S. mutans and Lactobacilli as indicators of dental caries development in patients with systemic sclerosis. Methods: In this cross-sectional study, ۸۰ patients with systemic sclerosis were assigned into ۲ groups, anti-centromere antibody (ACA) positive (n=۴۲) and ACA-negative (n=۳۸). Besides, ۸۰ age- and gender-matched healthy individuals were enrolled as control. Unstimulated saliva was collected in sterile tubes. Blood agar and tomato juice agar were used to cultivate S. mutans and Lactobacilli. The number of colony-forming units per milliliter (CFU/mL) was calculated and compared between the groups. Results: S. mutans in patients (median=۱.۶×۱۰۷ CFU/mL; interquartile range (IQR): ۱.۱–۳.۱ ×۱۰۷ CFU/mL) was significantly higher than control group (median=۵.۱×۱۰۶ CFU/mL; IQR: ۵.۱–۷.۹ ×۱۰۶ CFU/mL) (P<۰.۰۰۰۱, Mann-Whitney U-test); however, the median Lactobacilli levels was similar between these groups (۳.۴×۱۰۶ vs. ۲.۲×۱۰۶ CFU/mL; P=۰.۰۹۵). The median concentrations of S. mutans (۱.۳×۱۰۷ vs. ۲.۴×۱۰۷ CFU/mL; P=۰.۳۴۲) and Lactobacilli (۴.۱×۱۰۶ CFU/mL vs. ۳.۱×۱۰۶ CFU/mL; P=۰.۵۱۵) in the ACA-positive and ACA-negative patients had no significant differences. There were no significant correlation coefficients between S. mutans and Lactobacilli levels in the study groups (P>۰.۰۵). Conclusion: Our findings suggest the higher levels of salivary S. mutans in patients with systemic sclerosis might increase the likelihood of dental caries over time; however, it was not affected by the ACA status.

Lactobacilli, Saliva, Streptococcus mutans, Systemic sclerosis, لاکتوباسیل ها, بزاق, استرپتوکوکوس موتانس, اسکلروز سیستمیک