Measurement of caries Flashcards
What is caries?
A process of dynamic demineralisation and remineralisation where demineralisation exceeds remineralisation
What happens to ions in enamel at Low Ph?
Diffuse out of enamel
What are the methods for diagnosing caries?
Visual examination Tactile examination Transillumination Radiographs Electrical techniques
What does visual examination of caries require?
Good light, dry and clean teeth, mouth mirror, time
What is tactile examination of caries?
Useful for difficult to see surfaces
- Blunt explorer passed gently over surface of tooth
What are radiographs useful for?
Approximal but less for occlusal surfaces
Why is caries diagnosis difficult in individuals?
Mouth is dark, wet & mobile with small opening
Early changes are subtle
Commonest sites for caries are difficult to access
Consequences of incorrect diagnosis are severe
Consequences of incorrect diagnosis technique severe:
Indirect damage to teeth through misdiagnosis
Direct damage to teeth with diagnostic implement
More difficult at lower caries levels
More difficult in presence of fluoride. ‘Fluoride bombs’
Why is caries diagnosis difficult in groups of people?
Diagnostic agreement between dentists poor
One dentist makes different decisions @ different times
In groups consequences of incorrect Dx are severe:
Over or underestimate prevalence of disease
Miscalculate effectiveness of interventions
Misdirect resources
Why do we need to measure caries in individuals and in groups?
Diagnosis in an individual patient
Assess disease levels in a group Identify groups were disease is less common Identify causes of disease Explain how prevention works Assess the effectiveness of prevention Fissure sealants, water fluoridation etc
What is DMF index summarised by?
Population mean
Proportion caries free (% with DMFT = 0)
What are some examples of using the DMF index?
Dean’s 21 cities studies
Charting the decline in caries
Comparing caries
Identifying causes and determinants of oral health
What did dean’s 21 cities study look at?
Compared levels of caries (DMFT) and fluorosis in 21 US cities
Cities had varying levels of water fluoridation
Set optimal level for water fluoridation
What are the problems with DMFT?
- Difficulties of caries diagnosis remain
• Cumulative & irreversible
High DMF may mean caries in past, not recently
Age specific
• Does not distinguish between treated and untreated decay
Placing filling in cavity doesn’t change DMF
• Does not distinguish severity of disease
Tiny occlusal cavity = an extracted tooth
• Does not record secondary caries or replacement fillings
Therefore insensitive to changes in dental status in adults
• Aggregates caries and treatment experience
Influenced by treatment decisions of dentists
So less accurate as index of caries in adults
• Cannot distinguish teeth extracted due to caries or other reasons
E.g. exfoliation and orthodontic extractions
What are some other ways of measuring caries?
- Measures of oral health related quality of life to supplement or replace clinical indices such as DMFT
- Capture impact of disease on people’s daily lives
- Different questionnaires designed to be completed by:
adults – oral health impact profile, oral impacts on daily performance - children – child perceptions questionnaire, CARIES-Questionnaire for Children
What is the pH of the normal saliva?
6.2-7.0
