Researchers followed 33 dental students for 25 years to understand how daily habits damage teeth in ways that aren’t caused by cavities. They used 3D computer imaging to measure changes in tooth wear, gum recession, and small notches that form near the gum line. The study found that aggressive brushing, smoking, alcohol use, and bite problems are the main culprits behind these changes. The good news? Most of these risk factors are things you can control by changing your habits and being gentler with your teeth.

The Quick Take

  • What they studied: How teeth change over 25 years from everyday wear and tear, focusing on three types of damage: small notches near the gum line, gum recession (gums pulling away from teeth), and wearing down of the biting surface.
  • Who participated: 33 dental students who were tracked from the beginning of their studies through 25 years of their careers. Researchers collected information about their brushing habits, diet, smoking, alcohol use, and other lifestyle factors.
  • Key finding: Aggressive toothbrushing, smoking, alcohol consumption, and bite problems were the strongest predictors of tooth damage over time. Interestingly, these factors had different effects on different types of tooth damage, suggesting multiple pathways to harm.
  • What it means for you: If you brush too hard, smoke, drink alcohol regularly, or have bite problems, you’re at higher risk for tooth damage that may eventually require dental treatment. The encouraging part: most of these factors are within your control, meaning you can reduce your risk by changing habits and being gentler when brushing.

The Research Details

This study followed the same group of people over 25 years, making it a long-term observational study. Researchers took dental impressions (molds) at the start and again 25 years later, then used advanced 3D computer software to precisely measure how much the teeth had changed. They also analyzed bite patterns using a special sensor system to see if uneven biting forces contributed to tooth damage. Participants completed questionnaires about their daily habits, diet, and health to identify which behaviors might be linked to tooth damage.

The researchers measured three specific types of tooth damage: small notches that form where the tooth meets the gum (called non-carious cervical lesions), the amount the gums had receded or pulled away from the teeth, and how much the chewing surfaces of the teeth had worn down. They then used statistical analysis to determine which habits and factors were most strongly associated with each type of damage.

This approach is valuable because it tracks real people over a very long time period, allowing researchers to see actual patterns of tooth damage as they develop naturally, rather than trying to recreate them in a laboratory.

Long-term studies like this are rare and valuable because tooth damage develops slowly over years. By following the same people for 25 years, researchers could identify which habits actually cause problems in real life, not just in theory. The use of 3D computer imaging allows precise measurement of tiny changes that would be impossible to detect by eye alone, making the results more reliable and accurate.

Strengths: This is a genuine 25-year follow-up study with the same participants, which is rare and valuable. The use of 3D digital analysis provides precise, objective measurements rather than subjective observations. Limitations: The sample size is relatively small (33 people), all of whom were dental students, so the results may not apply equally to everyone. Dental students may have better oral hygiene habits than the general population, which could affect how applicable these findings are to others. The study is observational, meaning it can show associations between habits and tooth damage but cannot prove that one directly causes the other.

What the Results Show

The study identified several key factors that increase tooth damage over 25 years. Aggressive or vigorous toothbrushing was one of the strongest risk factors for developing small notches near the gum line. This suggests that while brushing is essential for oral health, brushing too hard can actually harm teeth. Smoking and alcohol consumption were consistently linked to multiple types of tooth damage, affecting both gum recession and the notches near the gum line.

Bite problems—specifically when teeth don’t meet evenly or there are areas of excessive contact—were significantly associated with tooth damage. This suggests that how your teeth come together when you bite can influence long-term wear patterns. Interestingly, different teeth were affected differently: the back teeth (molars and premolars) on the lower jaw showed the most damage, suggesting these teeth bear more force during chewing.

The study also found that diet played a role, with frequent consumption of acidic foods and drinks being associated with increased damage. Dentin hypersensitivity (tooth sensitivity to temperature and touch) was linked to both gum recession and notches near the gum line, suggesting that these conditions often develop together.

When researchers looked at which factors were most important, mechanical stress (from aggressive brushing and bite problems) and lifestyle habits (smoking and alcohol use) emerged as the primary drivers of tooth damage over the 25-year period.

The study revealed that one-sided chewing (favoring one side of the mouth) was associated with increased wear on the biting surfaces of teeth. Long-term orthodontic treatment (braces) was also linked to increased wear, possibly because the teeth are under sustained pressure for extended periods. Visible plaque buildup was associated with more notches near the gum line, suggesting that poor oral hygiene compounds the damage from other risk factors. The research also showed that the different types of tooth damage were related but distinct: gum recession and notches near the gum line showed moderate connections, but both had only weak connections to wear on the biting surfaces, indicating they may develop through somewhat different mechanisms.

This study builds on previous research showing that aggressive brushing can damage teeth, but it’s one of the longest follow-up studies examining this question. Earlier research has suggested links between smoking and tooth damage, and this study confirms those findings over a very long time period. The finding that bite problems contribute to tooth damage aligns with dental theory but provides concrete evidence from real patients over 25 years. The study’s use of 3D digital analysis represents an advancement over previous studies that relied on visual inspection or less precise measurement methods.

The biggest limitation is the small sample size of 33 people, all of whom were dental students. Dental students likely have better oral hygiene knowledge and habits than the general population, so these results may not apply equally to everyone. The study is observational, meaning it can show that certain habits are associated with tooth damage but cannot definitively prove that one causes the other—there could be other factors at play. The study doesn’t include information about professional dental treatments people may have received over the 25 years, which could affect tooth appearance and wear. Additionally, the study relied on participants’ memories and self-reports about their habits, which may not be completely accurate. Finally, the study only included people who were available for follow-up after 25 years, so people who moved away or had other reasons for not participating might have had different outcomes.

The Bottom Line

Based on this research, consider these evidence-based steps: (1) Brush gently with a soft-bristled toothbrush using light pressure—aggressive brushing doesn’t clean better and damages teeth; (2) If you smoke or drink alcohol regularly, reducing or eliminating these habits will significantly lower your risk of tooth damage; (3) If you have bite problems or uneven teeth contact, discuss this with your dentist, as correcting these issues may prevent future damage; (4) Limit acidic foods and drinks, or rinse your mouth with water after consuming them; (5) Have your dentist check for signs of tooth damage early, as catching problems early allows for better treatment options. Confidence level: Moderate to high for the brushing and lifestyle factors, as these were consistently associated with damage across multiple measures.

Everyone should pay attention to these findings, but especially people who: brush aggressively, smoke or drink alcohol regularly, have bite problems or misaligned teeth, consume acidic foods and drinks frequently, or have already noticed tooth sensitivity or gum recession. People with existing tooth damage should be particularly motivated to address controllable risk factors. However, these findings may be less directly applicable to people with very different oral health habits or those who have had extensive dental treatment.

Tooth damage develops slowly over years and decades, so you won’t see dramatic changes from habit changes in weeks or months. However, you may notice reduced tooth sensitivity within a few weeks of gentler brushing. Gum health may improve within 2-4 weeks of better oral care. Preventing future damage is the main benefit—by changing habits now, you can avoid the significant tooth damage that develops over 25 years. If you already have damage, stopping further progression is the realistic goal rather than reversing existing damage.

Want to Apply This Research?

  • Track brushing pressure and technique: Rate your brushing pressure on a scale of 1-10 (1 being very gentle, 10 being very aggressive) each time you brush. Aim to stay in the 2-4 range. Also track whether you’re using a soft-bristled toothbrush and note any changes in tooth sensitivity over weeks and months.
  • Set a daily reminder to ‘brush gently’ and use a timer to ensure you brush for 2 minutes without applying excessive pressure. If you smoke or drink alcohol, use the app to track consumption and set reduction goals. Log any signs of tooth sensitivity or gum changes to discuss with your dentist.
  • Monthly: Review your brushing pressure ratings and look for trends toward gentler brushing. Quarterly: Take photos of your gums to monitor for recession or changes. Track any changes in tooth sensitivity. Annually: Discuss findings with your dentist and compare notes on any visible changes in your teeth or gums. Use the app to maintain a long-term record of your oral health habits and any professional dental findings.

This research describes associations between habits and tooth damage observed in one group of dental students over 25 years. While the findings are scientifically sound, they may not apply equally to all people. This information is educational and should not replace professional dental advice. If you have concerns about tooth damage, sensitivity, or gum recession, consult your dentist for personalized evaluation and treatment recommendations. Do not attempt to diagnose or treat dental conditions based solely on this information. Individual results vary based on genetics, overall health, and many other factors not captured in this study.