My thought is that improper pH might might be a factor in bacterial growth and tooth decay. Supporting the idea is this research summary that implicates low pH (high acidity) to Fluorosis.


Since posting this I have become convinced that this is a thing so I have added some baking soda to my fluoride mouthwash to raise my oral pH (lower the acidity) and prevent fluorosis.

  • 2
    Two questions: 1) how would one regulate mouth pH and 2) what has your research revealed so far?
    – Carey Gregory
    Commented Apr 16, 2019 at 1:31
  • My thought is possibly through toothpaste. Baking soda? So far I've noticed that saliva is tasked with removing bacteria but according to science it doesn't work well enough by itself. I thought, "Well maybe the pH is off?" Dumb idea?
    – Ruminator
    Commented Apr 16, 2019 at 1:38
  • 2
    Your question needs some prior research to flesh it out. Mouth pH undoubtedly does affect bacterial growth, but how? And what does current research have to say about the matter?
    – Carey Gregory
    Commented Apr 16, 2019 at 1:57
  • I located this research that seems to show that sugar turns into acid in the mouth causing tooth decay and Flouride becomes toxic if you use it in a low pH (high acid) environment. Feel free to summarize it as an answer. ncbi.nlm.nih.gov/pmc/articles/PMC2878349
    – Ruminator
    Commented Apr 16, 2019 at 15:28
  • 1
    Good link. Please edit your question and add it to the question rather than leaving it as a comment.
    – Carey Gregory
    Commented Apr 16, 2019 at 18:24

1 Answer 1


The normal pH range of saliva is 6.2-7.6 (PubMed, 2013). The enamel starts to dissolve when the pH of the saliva or the fluid beneath the plaque falls under about 5.5, which is known as "critical pH" (Journal of Canadian Dental Association, 2003).

The pH of saliva falls, for example, when you drink acidic beverages, such as cola with pH 2.5-3.4 (PubMed, 2010).

The pH of the fluid beneath a dental plaque falls when the bacteria normally present in mouth convert certain nutrients, mainly sugars sucrose, glucose and fructose into acids (jisppd.com). Major sources of these sugars are table sugar, sweets, soft drinks, fruit juices and honey.

In one small study, oral rinse with sodium bicarbonate (baking soda) increased the pH of saliva, which could, theoretically, help to prevent tooth decay (PubMed, 2017).

I haven't found any human trials in which toothpaste would be used to increase salivary pH.

Salivary characteristics and dental caries: Evidence from general dental practices (PubMed, 2013)

Our study findings show that salivary characteristics were associated weakly with recent dental caries experience, but we did not find consistent trends among the three age groups. Thus, one should interpret with caution an assessment of salivary consistency, salivary pH or salivary flow rate to determine the caries risk of all patients.

In conclusion, one may not need to focus on salivary pH, but try to avoid known risk factors for caries, mainly sugary foods and bad teeth hygiene (Mayo Clinic).

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