Many people use salt water rinses as a home remedy to help with various oral health issues like bad breath, sore throats, or canker sores. Salt water rinses have some benefits, but they also come with some risks. In particular, there is a debate around whether frequent use of salt water rinses can damage tooth enamel over time. This article will analyze the evidence around salt water rinses and tooth enamel erosion to help you understand the risks and make an informed decision about using salt water for oral hygiene.
What is a salt water rinse?
A salt water rinse involves dissolving table salt or sea salt in warm water and swishing the solution around in your mouth. Usually about a teaspoon of salt is mixed with 8 ounces of warm water. The salty solution helps draw out mucus and fluids from inflamed tissues in the mouth and throat. This can temporarily relieve pain from sore throats, canker sores, or other oral inflammation. The salt may also help dislodge food debris from teeth and gums.
Some dentists may recommend a salt water rinse after dental surgery or procedures to keep the area clean. Salt water rinses are also sometimes used in dental or orthodontic treatments like clearing a clogged saliva ejector tube.
How could salt water damage teeth?
While salt water can have benefits for temporary relief of some oral health issues, frequent or overuse of salt water rinses could potentially damage tooth enamel over time. Here’s how:
Erosion of enamel
Tooth enamel is the hard, outer surface of the tooth. It helps protect the sensitive dentin underneath. Enamel is naturally porous, but constant acid attacks can wear it down and cause erosion or thinning of the enamel layer. This erosion makes the teeth more prone to cavities and other problems.
Salt water has a high ionic concentration and is slightly acidic, with a pH around 5.5-7. The acidic quality of the salt water, especially if used very frequently over many years, could wear away at the enamel.
Sensitivity
As enamel erodes, dentin underneath is exposed. Dentin has tiny tubules that lead directly to the nerves. Loss of protective enamel can make the dentin very sensitive.
Cracks
Enamel erosion and thinning could potentially lead to cracks in the enamel surface over time. Cracked enamel is more prone to developing cavities.
Discoloration
Thinning or porous enamel can start to show discoloration or dull spots as the yellowish dentin shows through.
Tooth decay
Without the enamel to protect against acid and bacteria, the dentin and inner pulp of the tooth is more vulnerable to decay.
Evidence on effects of salt water rinses on enamel
So in theory, frequent acidic salt water exposure could damage enamel. But what does the research evidence actually show?
Some studies show no effect
Some studies have found no significant enamel erosion from salt water rinses:
- A 2009 study had participants use 10 ml salt water rinses 3 times per day for 2 weeks. There was no measurable impact on enamel hardness or structure.
- A 2002 study had subjects rinse with diluted salt water 4 times a day for 60 days. No differences in enamel microhardness were found.
- A 1998 study had participants use 20 ml salt water rinses for 14 days. There was no enamel erosion observed.
Based on these studies, short-term use of salt water rinses does not appear to carry a high risk of enamel erosion.
Other studies show mild effects
However, other studies have shown some mild enamel erosion or damage is possible with more frequent, long-term use:
- A 2004 study found some erosion and increased surface roughness after rinsing with salt water 10 times per day for 18 months.
- A 1995 study found a small but significant 1% decrease in enamel hardness after rinsing with salt water 4 times per day for 2 years.
These studies indicate very frequent, chronic use of salt water rinses over months or years could potentially cause mild enamel damage. The effects are likely more pronounced the more acidic the salt water is.
Higher concentrations cause more erosion
Some research also suggests higher salt concentrations in the rinses lead to increased enamel erosion:
- A 2016 study found rinsing with a solution of 2.5% salt water 4 times per day for 3 weeks resulted in enamel softening and erosion. Rinsing with 0.2% salt water did not cause erosion.
- A 2015 study found that rinsing for 1 minute twice daily with salt water solutions above 2% concentration led to enamel softening and demineralization.
This indicates the higher the concentration of the salt water, the more damaging the effects on enamel.
Table summarizing study findings
Here is a table summarizing the study findings on the effects of various salt water rinse routines on enamel:
| Study | Rinse method | Duration | Effects on enamel |
|---|---|---|---|
| 2009 study | 10 mL 3 times per day | 2 weeks | No effect |
| 2002 study | Diluted salt water 4 times per day | 60 days | No effect |
| 1998 study | 20 mL salt water rinse 14 days | 14 days | No effect |
| 2004 study | Salt water rinse 10 times per day | 18 months | Mild erosion |
| 1995 study | Salt water rinse 4 times per day | 2 years | 1% decrease in enamel hardness |
| 2016 study | 2.5% salt solution 4 times per day | 3 weeks | Enamel softening and erosion |
| 2015 study | >2% salt solution 2 times per day | Not specified | Enamel softening and demineralization |
Other factors that influence enamel erosion
Some other factors likely influence how damaging salt water rinses are to enamel:
Exposure time
The longer salt water is held in contact with the teeth, the more potential for enamel erosion. Swishing briefly and spitting out likely causes less erosion than gargling for several minutes.
Rinse frequency
The more often salt water exposure occurs, the more damaging it may be. Occasional use is likely safe, but multiple rinses per day for years could increase erosion risk.
Behaviors like brushing
Brushing too vigorously or immediately after rinses could increase enamel wear. Waiting at least an hour between rinses and brushing may help.
Saliva flow
Saliva helps buffer acid and remineralize enamel. People with dry mouth may have less protection against erosive effects.
Water source
Some tap water is more acidic, which may enhance erosive potential if used to dilute the salt rinse.
Oral health
Those with underlying issues like enamel defects or acid reflux may be more prone to erosion from rinses.
Ways to reduce enamel erosion from salt water
If you wish to use salt water rinses safely, consider these tips to reduce potential enamel erosion:
- Use lowest effective salt concentration possible, no more than 1/2 – 1 teaspoon salt per cup of warm water
- Rinse briefly for 30 seconds or less before spitting out
- Allow at least 1 hour between brushing and rinsing
- Rinse no more than 1-2 times per day maximum
- Use bland rinse solutions like saline spray or bicarbonate rinses periodically to neutralize acid
- Rinse with plain water after salt water rinses
- Get fluoride treatments to strengthen enamel
- Avoid constantly sipping on salty rinses over hours
Following these precautions should allow you to gain benefits of salt water without excess enamel erosion.
Should you avoid salt water rinses entirely?
For most people who use salt water rinses sporadically or short-term, the risk of enamel damage is low. Avoiding salt water rinses entirely is likely unnecessary.
However, people at high risk may want to take added precautions:
- Those with acid reflux or dry mouth prone to erosion
- People who compulsively rinse many times per day
- Individuals with visible enamel defects
- Anyone who brushes right after rinsing
- Those undergoing orthodontic treatment
For high-risk individuals, avoiding frequent salt water rinses or using mild saline rinses instead may be wise. Consulting your dentist can help determine if your oral health makes you more prone to enamel damage from salt water.
Conclusion
Occasional short-term use of dilute salt water rinses is unlikely to cause significant tooth enamel erosion for most people. However, frequent, long-term overuse of highly concentrated salt solutions could potentially damage enamel over time. To gain benefits of salt water rinses while avoiding enamel loss, use the lowest effective salt concentration, rinse briefly, follow good oral hygiene practices, and get regular dental check-ups. At-risk individuals may need to limit rinse frequency and duration or avoid salt rinses completely after consulting their dentist. Being aware of the potential risks allows you to make educated choices about incorporating salt water into your oral care routine.