# Regular Physical Activity and Dental Erosion: A Systematic Review
## 4 Discussion  
Our systematic review found a relationship between the development of dental erosion and regular physical activity, especially with the accompanying consumption of sports drinks. Due to the variety of practised disciplines, it is difficult to relate summarised results to individual studies. Therefore, papers on relatively consistent groups of athletes were discussed in turn, starting with professionals and ending with amateurs. A large proportion of the included studies investigated the effect of swimming on oral health, particularly the presence of erosive lesions. [PERSON] et al. [28] analysed the prevalence of dental erosion among competitive and recreational 14- to 16-year-old swimmers in Szczecin, Poland. The competitive swimmers were from local sports clubs--junior subgroup training for about 7 years and senior subgroups training for about 10 years. Both subgroups spent over 19 h in the swimming pool per week. The recreational swimmers were randomly selected from students at high schools who were swimming once or twice per week and no more than 2 h per week. All participants trained in closely monitored, gas-chlorinated swimming pool water. Erosive lesions were observed significantly more often in the competitive swimmers than the recreational swimmers (26% and 10%, respectively). All lesions were grade 1, according to the Lussi classification. In the competitive swimmers, the anterior teeth were affected on both labial and palatal surfaces, whereas in recreational swimmers only palatal surfaces were affected. The erosion on the labial surfaces occurred only in senior competitive swimmers, especially in men. The authors suggest that the development of tooth erosion may be influenced by the length of training sessions and the duration of competitive swimming. Similarly, [PERSON] et al. [38] investigated the prevalence of oral health symptoms (such as dental hypersensitivity, dental erosion, and dental caries) among competitive swimmers from two training centres in Kottayam, India, and found that 69.6% of the included swimmers manifested dentin hypersensitivity, 48.2% dental erosion and 39.3% dental caries. Among the athletes complaining of dentin hypersensitivity, 61% had accompanying erosive defects. Dental erosion was observed more frequently on the palatal surface of the maxillary anterior teeth followed by the mandibular anterior teeth. In the study group, the incidence of erosion increased with the years of regular training at the pool. The odds of developing dental erosion in swimmers training for more than 3 years was 5.3 times higher compared to the rest. Furthermore, swimmers training for more than 2 h during a training session were more likely to be marked with erosive losses. Although almost two-thirds of them consumed acidic beverages, no correlation was found between the frequency of drinking and the presence of tooth erosion. The authors confirmed that dental erosion is an occupational risk for professional swimmers. Also, [PERSON] et al. [40] determined the prevalence of dental erosion among competitive swimmers. The participants of the cross-sectional study were 12- to 25-year-old swimmers regularly practising in Kaunas, the second largest city in Lithuania. Among them, 57.6% of the athletes were under the age of 18. Erosive lesions were observed in 25% of the underage swimmers and 50% of the adult swimmers. In total, more than one-third of the study group presented the occurrence of at least one erosion defect. The lesions were located mainly on the labial surfaces of the anterior teeth, not including any molar teeth. All of them were evaluated as grade 1 according to the Lussi index. Participants who had practised swimming regularly for more than 10 years were 3 times more likely to develop dental erosion compared to younger and less experienced swimmers. Among the athletes with tooth erosion, only 23% reported experiencing dental hypersensitivity.