Competitive swimming increases risk of dental erosion

In the recently published study, researchers at the Pomeranian Medical University analysed the prevalence of dental erosion among competitive and recreational swimmers from the local swimming club in Szczecin, Poland, who trained in a closely monitored gas-chlorinated swimming pool.

They found lesions on two or more teeth in 50 per cent of the senior competitive swimmers and in males in particular (42 per cent). They observed that lesions predominantly occurred on the labial surfaces in this group. A total of 25 per cent of the senior competitive swimmers displayed this type of lesion, with 21 per cent of them male and four per cent female. The researchers said that this sex variation could be attributed to longer sessions and the more aggressive style of men’s swimming.

While no labial lesions were found in recreational swimmers, erosion was observed exclusively on the palatal surfaces in this group, which the researchers presumed was related rather to dietary acid consumption. Both competitive (45 per cent) and recreational (74 per cent) swimmers frequently consumed dietary acids. In 25 per cent of the competitive and 11 per cent of the recreational swimmers, erosion was observed on the palatal surfaces of the anterior teeth.

According to the researchers, the labial surfaces of the maxillary incisors seemed to be subject to more erosion related to competitive swimming because these teeth were in continuous contact with pool water and not protected by salvia.

They suggested that an increased risk of erosion is likely associated with an undersaturation of pool water, as samples from the Szczecin pool showed that the water was undersaturated with respect to hydroxyapatite, with a pH of 7.2. The duration of swimming and the amount of training in such water were thus suggested to be the main risk factors for damage of the labial teeth surfaces.

“The dental literature suggests that pool water with a low pH can cause very rapid and extensive dental erosion. Therefore, intensive swimming should be considered a causative factor when diagnosing general dental erosion,” the researchers said.

According to the European Union regulations, the chlorine concentration in swimming pool water should be maintained within the range of 0.3 to 0.6 mg/dm³. As records showed, the chloride concentration of the pool water in the study had been maintained in the range of 0.3 and 0.5 mg/dm³ over the last two years prior to the study. The pH oscillated between 6.8 and 8.0, with an average of 7.2. The accepted pH range for swimming pools is between 7.2 and 8.0.

The study was conducted between October 2006 and January 2007 with 24 subjects from the local junior competitive swimmers group (12 females and 12 males) aged 14 to 15, who had been training for an average of seven years, and 38 subjects from the senior competitive swimmers group (13 females and 25 males) aged 15 to 16, who had been training for ten years. Both groups spent over 19 hours in the pool per week and the daily swimming duration was approximately four hours. The study also involved a group of 69 recreational swimmers (34 females and 35 males) aged 14 to 16, who swam once or twice a week for no more than two hours.

The article, “Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water”, was published online on 3 April 2012 in the Clinical Oral Investigations journal ahead of print.