Researchers wanted to understand why some young children get cavities while others don’t, even with similar brushing habits. They studied 58 children total—24 with cavities and 34 without—by testing their saliva for special protective proteins and cavity-causing bacteria. They found that children with cavities had higher levels of cavity-causing bacteria and ate sugary snacks more often between meals. Interestingly, one protective protein was actually higher in kids with cavities, suggesting their bodies might be trying harder to fight the bacteria. The study helps explain that cavities aren’t just about brushing—your body’s natural defenses and eating habits both play important roles.

The Quick Take

  • What they studied: Whether special protective proteins in saliva (spit) and cavity-causing bacteria levels are different between children with and without cavities
  • Who participated: 58 young children: 24 who had cavities and 34 who didn’t. All were healthy enough to participate in the study.
  • Key finding: Children with cavities had significantly more cavity-causing bacteria (Streptococcus mutans) in their saliva and ate sugary foods/drinks more than 3 times daily between meals. One protective protein (cathelicidin LL-37) was surprisingly higher in kids with cavities, possibly because their bodies were fighting harder against bacteria.
  • What it means for you: This suggests that cavity risk depends on multiple factors: the bacteria in your mouth, how often you eat sugary snacks between meals, and your body’s natural defenses. Limiting sugary snacks between meals appears especially important for cavity prevention.

The Research Details

This was a case-control study, which means researchers compared two groups of children—those with cavities and those without—to find differences between them. The researchers collected saliva samples from all 58 children and tested them in two ways: they used a special lab technique called PCR to count cavity-causing bacteria, and they used another technique called ELISA to measure protective proteins in the saliva. They also asked parents about their children’s eating habits and brushing routines.

The study was straightforward but important because it looked at the body’s natural defenses against cavities, not just brushing and flossing. By comparing children with and without cavities, researchers could identify which factors seemed most protective or harmful.

Understanding why some children get cavities helps dentists and parents focus on the most important prevention strategies. If we know that certain bacteria levels and eating habits matter more than others, we can give better advice. This study also explored whether the body’s natural protective proteins in saliva could explain cavity differences, which is a newer area of cavity research.

This study had a moderate sample size (58 children), which is reasonable but not huge. The researchers used reliable lab methods to measure bacteria and proteins. However, because this is a case-control study, it shows associations (things that go together) but can’t prove that one thing causes another. The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication. One limitation is that the study only included children from one location, so results might differ in other populations.

What the Results Show

Children with cavities had significantly higher levels of cavity-causing bacteria (Streptococcus mutans) in their saliva compared to children without cavities. This makes sense because this bacteria produces acid that eats away at tooth enamel, creating cavities.

Children with cavities also ate sugary foods and drinks more than three times per day between meals, which was statistically significant. This is important because bacteria feed on sugar, and eating sugary snacks frequently gives them more fuel to produce cavity-causing acid.

Surprisingly, one protective protein called cathelicidin LL-37 was actually higher in children with cavities. This might mean their bodies were producing more of this protein to try to fight the bacteria, suggesting their immune systems were working harder but perhaps not winning the battle.

Another protective protein called statherin showed no significant difference between the two groups, meaning it didn’t seem to play a major role in cavity development in this study.

The study found that cavity severity (measured by a score called dmfs) increased with age, meaning older children in the study tended to have more cavities. This is expected since cavities can accumulate over time. The research didn’t find major differences in brushing habits between the two groups, suggesting that diet and bacteria levels might be more important factors than brushing alone.

Previous research has shown that cavity-causing bacteria and diet are important for cavity development, and this study confirms those findings. The focus on protective proteins in saliva is newer research. While some studies suggested these proteins might protect against cavities, this study shows the relationship is more complex—having more of one protective protein didn’t prevent cavities in this group. This suggests that bacteria levels and diet may be more important than previously thought.

The study included only 58 children from what appears to be a single location, so results might not apply to all children everywhere. The study design (case-control) shows which factors are associated with cavities but can’t prove one thing causes another. The researchers didn’t measure all possible protective factors in saliva, so other proteins might also be important. Additionally, the study relied on parents reporting eating habits, which might not be completely accurate.

The Bottom Line

Based on this research (moderate confidence): Limit sugary foods and drinks between meals—this appears to be one of the most important changeable factors. Continue regular brushing and flossing as recommended by dentists. Visit a dentist regularly for checkups, especially if you notice your child has higher cavity risk. While the study doesn’t suggest you can change your protective proteins, maintaining good oral hygiene and diet supports your body’s natural defenses.

Parents of young children should pay attention to these findings, especially if their child has had cavities before. Children who frequently eat sugary snacks are at higher risk. Dentists may find this research helpful for understanding cavity risk. This research is less relevant for people with excellent cavity prevention habits or those with naturally low cavity risk.

Reducing sugary snacks between meals should show benefits within weeks to months, as you’ll give cavity-causing bacteria less fuel. However, cavities take time to develop, so you might not see a dramatic change in cavity numbers immediately. Consistent habits over 6-12 months are more meaningful than short-term changes.

Want to Apply This Research?

  • Track the number of times per day your child eats or drinks sugary items between meals, with a goal of reducing to fewer than 3 times daily. Use the app to log each snack and see weekly trends.
  • Set a specific goal like ‘Replace afternoon sugary snack with water or cheese’ and use the app to remind you before typical snack times. Track successful replacements to build momentum.
  • Monitor weekly snacking patterns and correlate with dental visit notes about cavity risk. Set a reminder for regular dental checkups (typically every 6 months) and track cavity status over time to see if dietary changes help.

This research describes associations between certain factors and cavities in a small group of children. It should not replace professional dental advice. Always consult with your child’s dentist for personalized cavity prevention strategies and treatment recommendations. This study shows what may be true for some children but doesn’t guarantee the same results for all children. Individual cavity risk depends on many factors not covered in this study.