Dental caries is listed by the WHO as one of the major non-communicable diseases that need to be prevented and treated. The aim of the study was to evaluate the prevalence and severity of caries expressed as the Decayed, Missing and Filled Permanent Teeth (DMFT) index in 12-year-old Polish children and to verify bacterial species related to the occurrence of dental caries. Quantitative real-time PCR analysis of DNA isolated from saliva samples was performed to detect 8 cariogenic and periopathogenic bacterial strains. A total of 118 Polish children were enrolled in the study. They had low mean DMFT scores of 1.58 ± 1.98. The prevalence of dental caries in the children tested was low (53.4%), with a tendency to decrease compared to previous oral surveys. Bacterial abundance of other species in the dental caries and caries-free groups did not differ; however, periopathogenic Prevotella pallens, Fusobacterium nucleatum along with cariogenic Streptococcus mutans and Lactobacillus fermentum were significantly strongly correlated in the caries-active subjects. The prevalence of S. sobrinus was significantly higher in children with dental caries (p = 0.023) and correlated with higher DMFT. It may temporarily play an important role in the initiation of the cariogenic process or in its enhancement due to an ecological imbalance in dental microbiota.

Changes to the features of the enamel surface submitted to induced demineralisation and subsequent remineralisation were studied. The in vitro examination was conducted on polished slices of human molar teeth, divided in four groups: the untreated control (n = 20), challenged by a demineralisation with orthophosphoric acid (H₃PO₄) (n = 20), and challenged by a demineralisation following remineralisation with fluoride (F) varnish containing casein phosphopeptides (CPP) and amorphous calcium phosphate (ACP) compounds (n = 20). The specimens’ enamel surfaces were subjected to analysis of structure, molecular arrangement, mechanical features, chemical composition, and crystalline organization of apatite crystals. Specimens treated with acid showed a significant decrease in crystallinity, calcium, and phosphorus levels as well as mechanical parameters, with an increase in enamel surface roughness and degree of carbonates when compared to the control group. Treatment with fluoride CPP–ACP varnish provided great improvements in enamel arrangement, as the destroyed hydroxyapatite structure was largely rebuilt and the resulting enamel surface was characterised by greater regularity, higher molecular and structural organisation, and a smoother surface compared to the demineralised one. In conclusion, this in vitro study showed that fluoride CPP–ACP varnish, by improving enamel hardness and initiating the deposition of a new crystal layer, can be an effective remineralising agent for the treatment of damaged enamel.

Oxygen is an essential element for sustaining the life of aerobes; however, in certain conditions it may be toxic for these organisms. This is due to so-called reactive oxygen species - ROS. Factors which cause the production of free radicals include ionizing radiation, UV radiation, high temperature, and hazardous substances, such as phenols, carbon monoxide, e.g. in smokers, also air pollution and drugs. The objective of the study was analysis of the total antioxidant status (TAS) in stimulated and unstimulated saliva, according to the number of active carious lesions in generally healthy non-smokers aged 15-17. The study covered 113 adolescents aged 15-17 in whom the state of dentition was evaluated using the DMFT (Decayed-Missing-Filled) index, and oral hygiene assessed based on the OHI-S (Oral Hygiene Index-Simplified) index. TAS in saliva was determined by means of a Randox Labolatories Ltd. test kit, by the spectrophotometric method. Based on the results of the study, it was found that in the population examined an increase in the number of carious lesions was accompanied by a significant decrease in the TAS, both in stimulated and unstimulated saliva. CONCLUSIONS. A health-promoting life style, maintenance of basic principles of oral hygiene and care of general health through the elimination of harmful habits decrease the risk of dental caries.