Sir, we are writing to share best practice with your readers and invite them to help us support more mothers to breastfeed.

Babies who are formula fed are at significant disadvantage with regards to short and long term illness, including infections, diabetes and allergy. Breastfeeding mothers are also at a lower risk of long term health conditions including female cancers and osteoporosis. The DH recommends babies be exclusively breastfed for six months, and then receive breast milk alongside solid foods for at least 12 months. The World Health Organisation urges mothers to breastfeed for at least two years, based on evidence of benefit to the health of mother and child.

Despite this there have been concerns that long term breastfeeding could contribute to dental caries in the baby, and this has been reflected in advice from some dentists and dental health organisations to limit breastfeeding frequency and duration. For example, the website of the British Dental Health Foundation recommends that babies are weaned from breastfeeding at around six months to prevent dental caries.

This concern is based on case reports from two small studies which were reported in the 1970s.1,2 In these cases, all nine children presented with caries and had been breastfed for over one year, and at night. A causal association was found by the authors, which prompted advice to parents to cease breastfeeding once the teeth erupt.

More recent research has demonstrated a positive association between breastfeeding and dental health. Among breastfed children, the longer the duration of breastfeeding, the lower the incidence of malocclusion.3 Also, children who have been breastfed show fewer decayed deciduous teeth than children not breastfed,4 which appears to contradict the earlier findings. The main risk associated with nursing caries in breastfed infants appears to be deficiency in the dental enamel, and this is coincidental to long term breastfeeding.

The mechanism of breastfeeding appears to protect the teeth against caries. Breast milk itself is protective against Streptococcus mutans. During breastfeeding, the milk is ejected into the rear of the oral cavity, and does not pool around the front teeth as occurs with a bottle. A study by Irish dentist Harry Torney found no association between long term on demand breastfeeding and dental caries.5

Parents require information about oral hygiene and dietary advice in order to reduce the risk of dental caries and those who have a family history of caries in infancy should be advised to register their baby with a dentist for early evaluation once the teeth have erupted. All family members should be encouraged in good oral hygiene during the pregnancy to avoid transfer of S. mutans. These factors are significant in reducing the risks in breastfed infants. For those parents who are bottle feeding, attention should be paid to ensuring the use of the bottle is for short periods, and only with milk. We would encourage parents to offer milk and water from cups from around six months.

Given the benefits for dental health, and the lack of any evidence of harm of long term breastfeeding, we call for our dental colleagues to support the DH and WHO recommendations and ensure parents are supported to breastfeed their infants for as long as they wish.