Researchers studied nearly 7,000 toddlers to understand what causes cavities in young children. They found that how long babies are breastfed and how many teeth have grown in by 18 months old can predict whether a child will get cavities by age 3.5. About 1 in 8 children in the study had cavities during this time period. The study suggests that parents should start thinking about their child’s dental health early, especially when deciding how long to breastfeed and making sure teeth are properly cared for as they come in.

The Quick Take

  • What they studied: Whether breastfeeding duration and the number of baby teeth that have grown in by 18 months can predict which children will develop cavities by age 3.5 years
  • Who participated: 5,161 children around 3.5 years old from a larger group of 6,746 children. Researchers measured their height and weight, looked at their teeth, and asked parents questions about feeding and care
  • Key finding: Children who were still breastfeeding at 18 months, or who had very few teeth (12 or fewer) or many teeth (17 or more) at that age, were more likely to have cavities by age 3.5. About 13% of children studied had experienced cavities during this period
  • What it means for you: Parents should talk to their dentist early about breastfeeding plans and tooth care. Starting dental visits and good oral hygiene habits when baby teeth first appear may help prevent cavities. However, this study shows a connection, not that breastfeeding causes cavities—other factors like diet and cleaning habits matter too

The Research Details

Researchers collected information from a large group of children around 3.5 years old. They measured each child’s height and weight, examined their teeth to check for cavities, and asked parents detailed questions about how they fed their baby (breast milk, formula, or both) and other health habits. They then used statistical analysis to figure out which factors were most connected to cavity development.

The study looked back at what happened when children were 18 months old and compared it to their dental health at 3.5 years. This approach helps researchers understand which early signs might warn parents that a child could be at higher risk for cavities.

By studying a large number of children and looking at multiple factors together, researchers can identify patterns that might help doctors and parents prevent problems before they start. Understanding the connection between breastfeeding, tooth development, and cavities helps create better guidance for families during these important early years

This study included a large number of children (over 5,000), which makes the findings more reliable. Researchers directly examined children’s teeth rather than relying only on parent reports. The study was published in Scientific Reports, a well-respected scientific journal. However, the study shows connections between factors, not definite cause-and-effect relationships, and other unmeasured factors could play a role

What the Results Show

The research found that about 13 out of every 100 children had experienced cavities between 18 months and 3.5 years old. Children who were still breastfeeding at 18 months had a higher risk of cavities by age 3.5. Interestingly, the number of teeth that had grown in also mattered—children with very few teeth (12 or fewer) or unusually many teeth (17 or more) at 18 months were more likely to develop cavities.

When children were receiving both breast milk and formula at 18 months, they also showed increased cavity risk. The study suggests these factors at 18 months can help predict which children might need extra attention to prevent cavities in the following years.

The findings were statistically significant, meaning researchers are confident these patterns are real and not due to chance. However, it’s important to note that having these risk factors doesn’t mean a child will definitely get cavities—it just means they’re at higher risk.

The study measured children’s height and weight but didn’t find these to be major factors in cavity development. The research focused specifically on the 18-month age point because this is when most children have started getting their baby teeth and feeding patterns are often still being established. This timing appears to be important for understanding later dental health

The relationship between breastfeeding and cavities has been debated among researchers for years. Some studies suggest breastfeeding protects teeth, while others suggest it might increase cavity risk if not combined with good oral hygiene. This study adds important information by showing that the timing and combination of feeding methods matter. It also highlights that tooth development patterns are connected to cavity risk, which helps explain some of the mixed findings from previous research

The study shows connections between factors but cannot prove that breastfeeding directly causes cavities. Many other factors affect cavity development—like how often parents clean teeth, what foods children eat, and whether they visit the dentist—and these weren’t all measured in detail. The study included children from a specific population, so results might differ in other groups. Additionally, researchers relied on parents to remember details about feeding practices from several months earlier, which could lead to some inaccuracy

The Bottom Line

Parents should start dental care early—ideally when the first tooth appears. Regular dental visits beginning around 12 months old are recommended. Good oral hygiene habits, including gentle tooth cleaning, should start as soon as teeth emerge. Parents should discuss breastfeeding duration and weaning plans with their pediatrician and dentist. Limiting sugary foods and drinks, and avoiding putting babies to sleep with bottles, helps prevent cavities. These recommendations are supported by strong evidence from this and other studies

All parents of young children should pay attention to these findings, especially those planning to breastfeed or currently breastfeeding. Parents whose children have delayed tooth development or are developing teeth unusually quickly should discuss this with their dentist. Children with early signs of cavities or those from families with high cavity rates should receive extra preventive care. However, this study doesn’t mean breastfeeding is bad—it means early dental care and good habits are especially important for breastfed children

Cavity prevention is a long-term process. Parents who start good oral hygiene habits and regular dental visits when teeth first appear should see benefits throughout early childhood. The study looked at children up to 3.5 years old, so benefits of early prevention would be most visible by this age. Establishing good habits now creates a foundation for healthy teeth throughout childhood and into adulthood

Want to Apply This Research?

  • Track your child’s first dental visit date and create reminders for regular check-ups every 6 months. Log when teeth first appear and note any changes in appearance. Record daily tooth-brushing habits and dietary changes to identify patterns related to oral health
  • Set a daily reminder to brush your child’s teeth gently with a soft toothbrush when the first tooth appears. Schedule the first dental visit by 12 months old and add it to your calendar. Create a feeding log that notes breastfeeding duration and introduction of other foods, then share this information with your dentist
  • Use the app to track the number of teeth present at each month and compare to typical development timelines. Monitor any visible changes in tooth color or appearance. Keep notes on dietary habits, especially sugar intake, and correlate with dental visit findings. Review trends quarterly with your pediatrician or dentist to adjust prevention strategies as needed

This research shows connections between breastfeeding, tooth development, and cavities in young children, but does not prove that breastfeeding causes cavities. Breastfeeding has many important health benefits and should not be discontinued based on this study alone. Parents should discuss their individual child’s feeding and dental care plans with their pediatrician and dentist. This information is educational and not a substitute for professional medical or dental advice. Every child is different, and recommendations should be personalized based on individual circumstances and professional guidance.