Sugars and Caries and Erosion

Question 1

Aetiology of Caries

Answer 1

1. Sugars, particularly free sugars, are a key factor in dental caries, providing a substrate for bacteria to produce acids that demineralize tooth enamel.
2. Sucrose is the most cariogenic sugar due to its role in acid production and aiding bacterial adhesion in plaque.

Question 2

Evidence from studies on diet and dental caries

Answer 2

1. Epidemiological studies: Cross-sectional, cohort, and population-based studies consistently show a strong link between high sugar intake and increased dental caries.
2. Animal experiments: Reduced sugar consumption in animals leads to significant reductions in caries, supporting human findings.
3. Plaque pH studies: Sugars cause a rapid drop in plaque pH, leading to demineralization and increased caries risk.

Question 3

Justification for current sugar intake recommendations

Answer 3

1. WHO recommends limiting free sugar intake to under 10%, with further reductions to 5% suggested, based on strong evidence from population and cohort studies.
2. Studies show that lower sugar intake is associated with fewer dental caries, and limiting intake to <5% may further reduce lifelong caries risk.

Question 4

Relative importance of the amount of sugars consumed vs. the frequency of consumption

Answer 4

1. Both amount and frequency of sugar intake influence dental caries.
2. Human cohort studies suggest the amount of sugar is more strongly linked to caries than frequency
3. Reducing frequency alone will not significantly impact non-communicable diseases associated with sugar​

Question 5

Effect of different types of sugars on dental caries:

Answer 5

1. All free sugars are considered a risk for caries; substituting one for another provides no benefit
2. Sucrose is more cariogenic than other sugars due to its role in increasing bacterial plaque and acid production
3. Lactose is less cariogenic than other sugars, and fructose leads to fewer pre-cavity lesions than sucrose​.

Question 6

Role of dietary starch in dental caries

Answer 6

1. Raw starch is not cariogenic, but cooked starch can cause caries, though less so than sucrose.
2. Processed starches combined with sugars increase caries risk, similar to sugar alone.
3. Population studies show decreased caries when sugar intake is reduced, even with higher starch intake.
4. Rapidly digestible starches increase caries risk, especially when consumed with sugars​

Question 7

Role of diet in the aetiology of dental erosion

Answer 7

1. Dental erosion occurs due to the chemical etching of dental hard tissue by acids, without bacterial involvement​.
2. The main dietary contributors to dental erosion are extrinsic acids, such as those found in carbonated drinks, fruit juices, wine, citrus fruits, pickles, and vinegar​. Frequent consumption of these acidic foods and beverages increases the risk of enamel erosion​.
3. Intrinsic acids from conditions like gastro-oesophageal reflux or frequent vomiting (e.g., in alcoholics or individuals with eating disorders) also contribute to erosion, but diet plays a predominant role in most cases​

Question 8

Critical appraisal of evidence for the role of diet in dental erosion

Answer 8

1. Case studies show severe erosion from behaviors like sucking on lemon wedges, holding cola in the mouth, and excessive citrus fruit consumption​.
2. Intervention studies (though limited due to ethical concerns) show that frequent consumption of drinks like orange juice or cola can cause erosion within 4-6 weeks​
3. Cross-sectional studies consistently link high intake of acidic drinks, citrus fruits, and sports drinks with increased dental erosion.
4. Animal studies demonstrate that fruit juices are 3-10 times more erosive than whole fruits, further supporting the role of processed acidic beverages in erosion.
5. Experimental studies highlight that the erosive potential of foods and drinks is linked to factors like pH, titratable acidity, and chelating properties, with drinks like Coca-Cola and fruit juices being highly erosive due to their low pH and high acid content​.

Question 9

Dietary advice for preventing dental erosion in line with general health recommendations

Answer 9

1. Limit frequency of acidic drink consumption (including diet varieties), as frequent acid exposure increases erosion risk​.
2. Consume drinks quickly, avoid swishing them around the mouth, and use a straw positioned towards the back of the mouth​.
3. Follow meals or drinks with neutral foods, such as milk or cheese, to neutralize the acid.
4. Avoid acidic drinks before bedtime, as saliva flow decreases during sleep, reducing the mouth’s natural defense against acid​.
5. Opt for drinks that are specially formulated to be less erosive, to protect dental health while aligning with overall dietary recommendations for limiting sugar and acid intake​.

Question 10

Non-sugar sweeteners permitted for food use:

Answer 10

Approved non-sugar sweeteners in Australia include both bulk (nutritive) and intense (non-nutritive) sweeteners.
Examples of bulk sweeteners: Sorbitol, Mannitol, Xylitol, Maltitol, Isomalt, Lactitol, Hydrogenated glucose syrup.
Examples of intense sweeteners: Sucralose, Aspartame, Saccharin, Acesulfame-K, Stevia, Advantame, Alitame, Cyclamate, Neotame.

Question 11

Difference between nutritive and non-nutritive sweeteners:

Answer 11

Nutritive sweeteners (bulk sweeteners) provide calories and are typically less sweet than sugar. Examples include sorbitol, xylitol, and mannitol.
Non-nutritive sweeteners (intense sweeteners) are much sweeter than sugar and provide little to no calories. Examples include aspartame, sucralose, and stevia.

Question 12

Outcome of cariogenicity tests for nutritive and non-sugar sweeteners:

Answer 12

Sorbitol and Mannitol: These sweeteners are slowly fermented, with only slight decreases in plaque pH. They are non-cariogenic but may cause some minimal demineralization.
Xylitol: Xylitol is non-cariogenic and even has anti-cariogenic properties, reducing caries by increasing salivary flow and decreasing plaque accumulation. Studies show xylitol can reduce caries significantly when used in gum.
Sucralose: Non-cariogenic in animal studies.
Saccharin and Acesulfame-K: These sweeteners inhibit bacterial growth and have been shown to reduce dental caries in intervention studies.

Question 13

Advice for patients regarding non-sugar sweeteners and dental caries prevention:

Answer 13

Non-sugar sweeteners can be beneficial for dental health when substituted for sugar, especially between meals.
Xylitol-containing gums are particularly effective as they increase salivary flow and help neutralize acids after meals.
Non-nutritive sweeteners are safe for teeth and can help reduce the risk of dental caries, but they do not discourage a preference for sweet tastes, so overall moderation is still advised.