## 5 Caries Management with Probiotics  
Today, probiotics seem to be a salutary, newly derived method to control dental caries [9; 10]. The rationale of probiotics use in caries management is that probiotic microorganisms can expel cariogenic microorganisms and colonize the oral cavity. A wide variety of clinical trials have been conducted to examine probiotics' effect on dental caries and oral microflora. These studies are summarized in Table 2.  
Among most of these trials, dairy products remained a common denominator as an administration milieu [46; 47; 48]. Milk's colloidal nature seems to be enamel protective [88], as it contains organic and inorganic compounds assisting in compensating cariogenic challenges [89]. Another substrate of dairy formulations, calcium lactate, also possesses anti-cariogenic properties [90]. Therefore, dairy products may be ideal for probiotic administration. However, many other means have been proposed to serve as probiotic administration agents, especially for those allergic to dairy components. Among those means stand capsules or liquid form [43], specially prepared straws or tablets [27; 35; 41], drops [29], lozenges [54], and even sweetened cakes [55] and ice creams [44]. The first-ever study introducing probiotics to dental clinical practice was that of [PERSON] and his colleagues [20]. They suggested that _Lactobacillus Gorbach-Goldin_ (GG) - LGG, a strain earlier isolated by [PERSON] and [PERSON] [91], can colonize the human oral cavity. Nonetheless, its long-term beneficial effect on oral health and the resulting alterations in oral microflora remained unilluminated. [PERSON] et al. investigated _L. rhamns_ GG for its in vivo long-term effect (7-month period) on dental caries [21; 92]. They reported no significant changes in _S. mutans_ salivary counts and caries prevalence occurred, but a significantly lower caries-risk than in the control group. Following these results, [PERSON] et al. investigated the short-term anticaries effect of a cheese containing the same _Lactobacillus rhamns_ strain plus _L. rhamns_ LC 705 [22]. After a 3-week period, no statistically significant difference in _S. mutans_ counts between the intervention and the control group occurred. However, the probiotic-containing cheese was found to exert its enhanced anticaries potential during the post-treatment period, as the _S. mutans_ levels in saliva were significantly reduced. In 2003, [PERSON] et al. examined two extra facets of probiotics intended for oral administration [43]. Probiotic species tested in this study were _L. sporogens_ 16%, _L. bifidum_ 12%, _L. bulgaricus_ 12%, _L. thermophilus_ 18%, _L. acidophilus_ 20%, _L. casei_ 10%, and _L. rhamns_ 12%. The probiotics used, independently of the administration's milieu, were found to increase _Lactobacillus_ salivary counts in contrast to _S. mutans_. In fact, capsule and liquid forms were found to lead to equivalent results. The only practical difference between these two types of administration is that Lactobacillus strains diffused into the oral cavity in the liquid state. Thus, a systemic effect of oral probiotics was suggested. In 2004, [PERSON] et al. highlighted the selective bactericidal influence of _L. reuteri_ SD2112 (ATCC55730) on _S. mutans_ in vitro and in vivo [26]. The individuals consumed a cup (95 g) of placebo yoghurt (_S. thermophilus_ and _L. bulgaris_) once a day for two weeks during lunchtime in the first group. The following 2 weeks, a probiotic yoghurt containing _L. reuteri_ and _S. thermophilus_ was administrated in the same terms. In the second group, the opposite regimen was followed. Ultimately, both types of treatment significantly reduced the _S. mutans_ salivary carriage, compared to its baseline values for each group.