According to the assertions made by Hoffmann and Daniels (4), probiotics assumed the mechanism of action against co-aggregation in the oral cavities that resulted from infectious strains of microorganisms such as T. forsythia, P. endodintalis and P. gingivitis. Nonetheless, Connelly (17) posited that the periodontal inflammation in the mouth was subject to inflammation caused by bacteria and could only be treated upon probiotics administration. Shimitter et al. (18) outlined the mechanism of probiotics action by decreasing the quantities of inflammatory cytokines such as interleukin 8 and tumour necrosis factor-alpha in the treatment of dental infections. According to Riccia (19), probiotics are involved in the reduction of the levels of nitrates and nitrites as well as matrix metalloprotease and prostaglandins E2 for the elimination of inflammation in the oral cavity, which was heavily modulated by probiotics.
Probiotics have effects in boosting the immune system (20, 21) and can also enhance the activity of several immune cells such as the natural killer cells (4). Vicekananda, Vandana, and Bha (22) however posited that probiotics played essential roles in the reduction of the index of gingivitis. This action can be correlated to the effects of probiotics in the reduction of plaque scores as evident in a study conducted by Vicario, Santos, Violant, Nart and Giner (23). Hoffmann and Daniels (4) added that dental caries was associated with Lactobacillus and S. mutans bacterial strains. However, contradictory findings were elaborated in a study conducted by Smark-Mattison et al. (5), where patients free of dental carries exerted more effective inhibitory effects against mutant forms of Streptococci than Lactobacilli that was isolated from patients with dental caries. Washington, Washington and Wilson (24) ascertained that probiotic bacteria were instantaneously released from the probiotic orally disintegrating tablets (ODTs) at the action sites but was affected by the resident time in the oral cavity as a result of the constant flashing demonstrated by the reaction of saliva alongside drinking and eating.