Preventive Dentistry and Nutrition

Diet and Nutrition in Oral Health Practice Questions

20 free Diet and Nutrition in Oral Health practice questions for the CDA. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.

Practice in Quiz Mode

Question 1 of 20 Medium

How does frequent consumption of sugary snacks impact oral health?

  1. A It significantly increases resting saliva flow throughout the mouth
  2. B It raises caries risk by feeding bacteria constant carbohydrate
  3. C It gradually strengthens tooth enamel over a long period of time
  4. D It reliably prevents plaque from accumulating on the teeth

Correct answer: It raises caries risk by feeding bacteria constant carbohydrate

Frequent sugar intake promotes continuous acid production by oral bacteria. This leads to demineralisation and caries development.

Question 2 of 20 Medium

Which dietary factor has the greatest influence on caries formation?

  1. A Total calories consumed
  2. B Frequency of sugar exposure
  3. C Amount of fibre in the diet
  4. D Protein intake

Correct answer: Frequency of sugar exposure

Frequent sugar exposure causes repeated acid attacks on enamel. This is more harmful than the total amount of sugar consumed.

Question 3 of 20 Medium

Which type of food is most protective against caries due to its ability to stimulate saliva?

  1. A Dried fruits
  2. B Cheese
  3. C Sticky candies
  4. D Sports drinks

Correct answer: Cheese

Cheese stimulates saliva and provides calcium and phosphate. These help buffer acids and support remineralisation.

Question 4 of 20 Medium

Why are acidic beverages such as soda harmful to enamel?

  1. A They contain probiotics
  2. B They lower oral pH and promote erosion
  3. C They increase enamel hardness
  4. D They neutralise bacterial acids

Correct answer: They lower oral pH and promote erosion

Acidic drinks soften enamel by reducing pH. This leads to erosion and increases caries susceptibility.

Question 5 of 20 Medium

Which vitamin deficiency is associated with delayed wound healing in the oral cavity?

  1. A Vitamin C deficiency
  2. B Vitamin K deficiency
  3. C Vitamin D deficiency
  4. D Vitamin B12 deficiency

Correct answer: Vitamin C deficiency

Vitamin C supports collagen formation and tissue repair. Deficiency leads to poor healing and gingival bleeding.

Question 6 of 20 Medium

Which nutrient is essential for proper development and mineralisation of teeth?

  1. A Vitamin D
  2. B Vitamin E
  3. C Vitamin K
  4. D Iron

Correct answer: Vitamin D

Vitamin D helps regulate calcium and phosphorus absorption. These minerals are crucial for strong enamel and dentin.

Question 7 of 20 Medium

What effect does frequent consumption of sticky carbohydrates have on oral health?

  1. A They are easily rinsed by saliva
  2. B They remain on tooth surfaces and increase caries risk
  3. C They neutralise plaque acids
  4. D They reduce bacterial growth

Correct answer: They remain on tooth surfaces and increase caries risk

Sticky foods adhere to teeth and remain longer in pits and fissures. This prolonged exposure increases caries risk.

Question 8 of 20 Medium

What is the primary dental concern with sipping sugary beverages over long periods?

  1. A It improves digestion
  2. B It causes repeated acid attacks on enamel
  3. C It prevents dry mouth
  4. D It strengthens the periodontal ligament

Correct answer: It causes repeated acid attacks on enamel

Continuous sipping keeps oral pH low for extended periods. This creates ideal conditions for enamel breakdown.

Question 9 of 20 Medium

Which nutrient deficiency may contribute to angular cheilitis?

  1. A Dietary calcium intake
  2. B Vitamin B complex
  3. C Vitamin D
  4. D Vitamin A

Correct answer: Vitamin B complex

B vitamin deficiencies can cause cracking at the corners of the mouth. They are essential for mucosal health.

Question 10 of 20 Medium

How does adequate water intake support oral health?

  1. A By reducing calcium absorption
  2. B By maintaining salivary flow and rinsing away food debris
  3. C By increasing plaque thickness
  4. D By neutralising stomach acid

Correct answer: By maintaining salivary flow and rinsing away food debris

Water helps cleanse the mouth and maintain saliva production. Saliva is essential for buffering acids and protecting teeth.

Question 11 of 20 Medium

Which group of foods is most likely to cause dental erosion?

  1. A High-protein foods
  2. B Citrus fruits and carbonated beverages
  3. C Whole grains
  4. D Dairy products

Correct answer: Citrus fruits and carbonated beverages

Citrus fruits and sodas contain strong acids that dissolve enamel. Frequent exposure leads to erosion.

Question 12 of 20 Medium

What is a benefit of xylitol-containing gum?

  1. A It increases acid production
  2. B It reduces Streptococcus mutans levels
  3. C It coats teeth with calcium
  4. D It acts as a whitening agent

Correct answer: It reduces Streptococcus mutans levels

Xylitol inhibits cariogenic bacteria like S. mutans. Chewing gum also stimulates saliva, aiding remineralisation.

Question 13 of 20 Medium

Why is snacking on fruit juice worse for teeth than eating whole fruit?

  1. A Juice contains less sugar
  2. B Juice has more fibre
  3. C Juice is more acidic and lacks protective fibre
  4. D Whole fruit dissolves enamel faster

Correct answer: Juice is more acidic and lacks protective fibre

Juice exposes teeth to concentrated sugars and acids. Whole fruit contains fibre, which reduces contact with enamel.

Question 14 of 20 Medium

How does a diet low in calcium affect oral health?

  1. A It causes hyper-salivation
  2. B It weakens enamel and bone supporting the teeth
  3. C It prevents plaque formation
  4. D It increases tooth colour stability

Correct answer: It weakens enamel and bone supporting the teeth

Calcium is a key mineral for enamel hardness and bone density. Low intake weakens structural support.

Question 15 of 20 Medium

Which eating habit is most protective against caries?

  1. A Eating multiple sugary snacks throughout the day
  2. B Eating sweets only at mealtimes
  3. C Drinking sweetened beverages all day long
  4. D Snacking on sticky foods

Correct answer: Eating sweets only at mealtimes

Eating sweets with meals reduces caries risk because increased saliva flow during meals buffers acids.

Question 16 of 20 Medium

Which nutrient deficiency is associated with glossitis (inflamed tongue)?

  1. A Vitamin B12
  2. B Vitamin C
  3. C Vitamin D
  4. D Vitamin K

Correct answer: Vitamin B12

Vitamin B12 deficiency can cause smooth, painful tongue surfaces. It affects epithelial turnover in the oral cavity.

Question 17 of 20 Medium

Which type of carbohydrate poses the highest caries risk?

  1. A Complex carbohydrates
  2. B High-fibre carbohydrates
  3. C Simple fermentable sugars
  4. D Non-fermentable carbohydrates

Correct answer: Simple fermentable sugars

Fermentable sugars are easily metabolised by bacteria, producing acids. These acids directly cause enamel demineralisation.

Question 18 of 20 Medium

How does frequent vomiting in conditions such as bulimia affect teeth?

  1. A It causes tooth strengthening
  2. B It leads to erosion from stomach acid
  3. C It protects enamel through saliva production
  4. D It prevents plaque formation

Correct answer: It leads to erosion from stomach acid

Stomach acids erode enamel, especially on the palatal surfaces. Repeated exposure causes severe enamel loss.

Question 19 of 20 Medium

Which snack is least likely to contribute to dental caries?

  1. A Chocolate bar
  2. B Crackers
  3. C Fresh apples
  4. D Dried raisins

Correct answer: Fresh apples

Apples contain water and fibre, which help clean tooth surfaces. They do not adhere to teeth like sticky snacks.

Question 20 of 20 Medium

Which dietary advice is appropriate for reducing caries risk?

  1. A Sip sugary drinks throughout the day
  2. B Choose water between meals instead of sweetened beverages
  3. C Snack frequently on dried fruit
  4. D Avoid dairy products completely

Correct answer: Choose water between meals instead of sweetened beverages

Water is non-cariogenic and helps cleanse the mouth. Avoiding sugary drinks between meals reduces acid attacks on enamel.

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