How acidic does a food have to be?

Item pH

Tap water 7.0 – 7.7

Milk 6.4 – 6.8

Cheddar cheese 5.9 – 6.0

Bread 5.0 – 6.2

Bananas 4.5 – 5.2

Tomatoes 4.3 – 4.9

Beer 4.0 – 5.0

Ketchup 3.8 – 4.0

Root beer 3.8 – 4.0

Honey 3.7 – 4.2

Diet lemon-lime soda 3.7 – 3.8

Orange juice 3.3 – 4.2

Dill pickles 3.2 – 3.7

Lemon-lime soda 3.2 – 3.3

Blueberries 3.1 – 3.3

Apples 3.1 – 3.9

Diet cola 3.0 – 3.3

Grapefruit 3.0 – 3.8

Iced tea 2.9 – 3.0

Vinegar 2.4 – 3.4

Coffee 2.4 – 3.3

Cola 2.4 – 2.5

Sports drinks 2.3 – 4.4

Wine 2.3 – 3.8

Lemon juice 2.0 – 2.6

Mango Sours 1.9*

Sour Spray 1.6*

Battery acid 1.0

Table 1: Acidity of food and drink3

In laboratory experiments tooth enamel can begin to dissolve at pH 5.3 and dentin at pH 6.7.1,2 The pH ranges of some common foods and drinks are listed in Table 1.

However, pH is not the sole indicator of how erosive to teeth a substance can be. The total acid level (titratable acid or TA) is considered more important than pH because it determines the actual H+ available to interact with the tooth surface.5 Some foods are more readily neutralized by saliva than others.

• TA is a more representative measure of acidic challenge to the tooth.

• TA indicates how easily a food’s acidity is neutralized by saliva.

• The higher the TA of a food, the longer it may remain acidic in the mouth.

In most cases, the more acidic a food (i.e. the lower its pH), the higher its TA will be – see Table 2. However, the two measures do not always correlate directly. For example, dried apricots are less acidic than orange squash (pH 3.87 vs 2.82) but have a higher TA, meaning that they will leave an acidic environment in the mouth for longer and are therefore more erosive.

Table 2: Titratable acidity and pH of food and drink6

Foods TA (g/100g) pH

Seedless raisins 2.59 3.98

Dried apricots 2.49 3.87

Orange squash (50% fruit) 2.27 2.82

Pure orange juice (concentrate) 1.27 3.66

Organic bio yogurt (strawberry) 1.21 4.10

Pure apple juice (concentrate) 0.58 3.58

Natural cheese 0.50 5.01

Bananas 0.44 5.15

Apples 0.17 5.47

Pears 0.12 5.72

Strawberry-flavored milk 0.12 6.41

Whole milk 0.10 6.69

Water 0.02 7.28

* 1g candy dissolved in 5ml water4

How to identify tooth erosion

It’s important to identify signs of tooth erosion as early as possible so that significant demineralization can be avoided and damaging habits can be changed.

On examination, there may be three visible signs of tooth erosion:

1. Transparency of the incisors – acid erosion may cause a thinning at the incisal edge

2. Lack of surface ridges on the teeth – acid erosion causes a loss of surface structure

3. Erosive wear (cupping) on first permanent molars – at the back of the mouth erosion causes a similar loss of surface anatomy, classically with cupping.

Moderate erosive damageChanging shape and loss of contour. Surface lacks shine and looks dull

with no texture

Normal adult appearanceSome changes since emergence of adult teeth but a shiny white and naturally

textured surface

Early erosive damageLoss of shine and texture of enamel producing a dull yellow appearance

Examples of acid erosion in adults (adapted from8)

References: 1. Cate JM, et al. Caries Res 1983, 17: 193-199. 2. Hoppenbrouwers PM. Arch Oral Biol 1987; 32: 319-322. 3. U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, April 2007; Jain, Nihill, Sobkowski, Agustin, General Dentistry,March/April 2007. 4. Loewen RR, et al. Journal of the Minnesota Dental Association. 2008; 87(2). 5. Bamise CT, Bamise OF. The Internet Journal of Dental Science, 2008; 6: 1. 6. GSK Data on File. 7. Data on File (GSK Market Research Data). 8. Lussi A, Jaeggi T. Monogr Oral Sci 2006; 20: 140-151.

Severe erosive damageTotal loss of biting edges of front teeth, producing rough and brittle surfaces

“50% of US dental professionals report seeing an increase in acid erosion compared to 5 years ago”7