The Oral Environment 3 Flashcards
What is the volume of saliva in the mouth?
1.1 ml (range = 0.5ml-2.1ml)
What is the area in the mouth that saliva is dispersed over?
Approximately 200cm2
What is the thickness of the film of saliva that covers the mucosa?
50-100 nanometres
Is the film of saliva in the mouth in motion or static?
In motion
Where is salivary flow highest in the mouth?
In lower, lingual regions
Where is salivary flow lowest in the mouth?
In labial and buccal regions
What is meant by clearance?
Refers to the rate at which substances are removed from the mouth
What factors is clearance related to?
- Salivary film velocity
- Location in mouth
What are the important oral health aspects of clearance?
- Removal of ‘harmful’ materials
- Retention of ‘beneficial’ materials
What is rapid clearance?
High salivary flow rates
What is slow clearance?
Low salivary flow rates
How do plaque micro-organisms generate acid?
By metabolising sugars such as sucrose
What is a graph of the plaque pH change over time called?
A Stephen curve
What are examples of bulk caloric (cariogenic) sweeteners?
- Sucrose
- Fructose
- Glucose
- Lactose
What are non-caloric/high intensity sweeteners (non-cariogenic)?
- Aspartame
- Cyclamates
- Saccharin
- Sucralose
What are low caloric sweeteners?
- Mannitol
- Sorbitol
- Xylitol
When do patients complain of ‘dry mouth’?
When salivary flow rates fall below 50% of normal levels
What is the unstimulated flow rate of a person with Xerostomia?
< 0.1ml/min
normal = 0.2-0.4 ml/min
What is the stimulated flow rate of a person with Xerostomia?
< 0.5ml/min
normal = 1.0-5.0 ml/min
What are the causes of decreased salivary flow?
- Side effect of many drugs
- Radiotherapy
- Diseases:
- Specific salivary gland diseases
- Systemic diseases that also affect salivary glands
- More general conditions that may affect salivary glands
What is a condition that affects salivary glands and other tissues?
Sjogren’s syndrome
What type of carried can be related to reduced salivary flow and clearance?
Cervical caries
What are the consequences of decreased salivary flow?
- Increased dental caries
- Increased oral disease
- Dysaesthesia (‘burning’ mouth)
- Impaired oral function
- Diminished taste perception
What are the protective components that are lost with decreased salivary flow?
- Antimicrobial agents
- Buffering
- Decreased remineralisation
- Mucins and other proteins
- Gustin
- Consumption of cariogenic confectionary to increase salivation
How can you treat Xerostomia?
- If there is functioning gland tissue present, stimulate salivary flow for example by chewing or by drugs
- If there is no functioning gland tissue, saliva substitutes may be used:
- Mucin-based; cellulose based
- Water along is not very effective
