Cariology Flashcards
Understand the role of the oral biofilm in caries development
Acid production
• The bacteria in the biofilm like simple carbohydrates
• They only use glycosis step, using anaerobic respiration
• The glycolosis step produces a lot of acid as a by-product
• With acidic production comes demineralisation
Bacteria
• Once acid is produced, it selects the growth of aciduric bacterial species. * They are acid tolerant and acid producing
• This is when the biofilm becomes cariogenic
Describe the specific plaque hypothesis
• When people would study bacteria present in plaque, they found the most recurring bacterial causants to be; streptococcus mutans, streptococcus sobrinus
* This became the specific plaque hypothesis: these bacteria cause caries
Describe the non-specific plaque hypothesis
• Took DNA samples from the oral biofilm, amplified a specific gene, cloned it and identified microorganisms carrying that gene
* It showed that many different types of bacterial species were responsible for caries
Describe the ecological plaque hypothesis
• Considers the oral environment as a microbial ecosystem
• Caries is therefore. Caused by a dysbiosis: imbalance of normal microflora
• The causes of microbiota shift are; pH, nutrient availability, O2 concentration and the genetic environment of the host
* When studying caries in people, it was found that there was reduced bacterial diversity and a dominance of lactobacilli
Understand the microbiome perspective of caries
- Microbiome is the genetic material of all the microbes; bacteria, viruses, archaea, fungi, that live inside the human body. It is individual to each organism
- Microbiota refers to the microorganisms found in the environment
- The oral microbiome is diverse, and site specific (different bacteria in different sites of the mouth). Bacteria from the same species also possess variation
Describe how microbiome data can be used to direct new treatment approaches for caries
Having access to microbiome data enables the following:
Prevention:
• Identification of high risk individuals
• Informing when preventative measures are required
• Development of early detection methods
Treatment - Oral biofilm modulation
• Antimicrobial development
* Probiotics development and testing against these types of microbiota
What is the size and impact of the caries problems?
- Hospitalisation
- Pain and discomfort
- Systemic infections
- Predictor of poor general health
- Discomfort about appearance
- Speech and learning difficulties
- Eating and drinking difficulties
What lead to the specific plaque hypothesis?
• S mutans was always found in carious lesions
• S mutans induced caries in mouse fed a high sucrose diets
• S mutans is highly aciduric
* S mutans is sticky, and is an initial tooth colonisers, thus it promotes adhesion
What disproves the specific plaque hypothesis?
• Culture methods can only identify ~50% of bacteria
• The bacteria Streptococcus mutans is ubiquitous in the oral cavity, it’s everywhere, and so it might not be the only caries causer
• You can get caries without S mutans
* Other aciduric bacteria involved in carious lesions
Discuss the need for the categorisation of various carious lesions
• It enables an understanding of the extent of the problem and thus informs the types of treatment needed
• It enables communication to one’s dental team
* It enables the classification of the problem and thus guides treatment planning
Identify the clinical signs and symptoms of various stages of the carious lesion according to the ICDAS-II
Code 0: normal appearance when wet AND dry
Code 1: normal appearance when wet BUT white or brown spot lesions when dry
Code 2: white/ brown spot lesion when wet AND dry
Code 3: white/ brown spot when wet BUT enamel loss when dry (0.5mm of the WHO probe drops when the probe is run along the surface of the cavity)
Code 4: A shadow from dentine plus OR minus lost enamel
Code 5: Cavitation WITH exposed dentine
Code 6: Extensive cavitation
Identify the clinical instruments and equipment used for the detection of the carious lesion
• Sharp eyes
• WHO or any BLUNT probes; sharp explorers can cause cavitation in areas that are remineralising
* Bitewings; interproximal lesions, checking if t has progressed to dentine
How do you tell apart a stained fissure from a carious lesion?
- A brown spot carious lesion will always be centered within a white spot
How to tell about fluorosis/ idiopathic lesions from caries?
• Caries lesions DO NOT OCCUR on smooth surfaces mid-way between the gum margin and the occlusal surface/incisal edge UNLESS that surface is covered with thick plaque.
- Caries lesions DO NOT OCCUR on incisal edges or on occlusal surfaces because plaque is disturbed at these sites during mastication
- WSL are one areas where plaque accumulation is undisturbed
How to tell apart flourosis from idiopathic lesion?
Fluorosis:
• Left- right symmetry
• Seen near tips of cusps or incisal edges
• Incremental lines in enamel
• Diffuses seamlessly into normal enamel
• Opaque (not see through) with paper white flecks across tooth surface
Idiopathic lesion: • Not symmetrical/ left and right • Seen on nearly whole crown • Has a clear circumference * Distinctly different from normal enamel
