Dental Caries Flashcards
1
Q
Dental caries - Definition?
A
- a bacterial disease of the calcified tissues of the teeth characterised by the demineralisation of the inorganic and destruction of the organic substance of the teeth
2
Q
Dental caries - Acidogenic theory of dental caries? What happens? What’s affected?
A
What happens:
- result from a metabolic shift accompanied by gradual change in ecology of the dental biofilm
- imbalance in equilibrium between tooth mineral and biofilm fluid develops
- acid produced by oral bacteria from carb fermentation
What’s affected:
- decalcification of hard tissue substance and disintegration of the organic matrix
3
Q
Dental caries - Aetiology of caries? Primary and secondary modifying factors?
A
Primary: - morphology - saliva - pH - fluoride - diet - hygiene - immune - genetic Secondary: - socioeconomic - education - lifestyle - environment - age - ethnic group - occupation
4
Q
Dental caries - Bacterial metabolism? Acquired pellicle? Dental plaque? Defintion?
A
Acquired pellicle:
- absorbed layer of mainly salivary glycoprots that forms on clean enamel, which bacteria adheres to
Dental plaque:
- biofilm of bacteria embedded in matrix of salivary mucins and extracellular polysacchardie polymers (on all surfaces)
5
Q
Dental caries - Development of dental biofilms - process?
A
Process:
- pellicle forms
- attachment of bacterial colonisers (0-14h)
- co-adhesion and growth of attached bacteria leading to microcolonies (4-24h)
- microbial succession leading to increased bacterial diversity with continued adhesion and growth (1-7d)
- climax community/mature biofilm (1 week)
6
Q
Dental caries - Initial colonisers - types? content? nutrients?
A
Types: - S.sanguis/oralis and mitis - Actinomyces and Neiserria Content: - 95% strep - 56% total microflora Nurients: - endog molecules of saliva
7
Q
Dental caries - Microbial succession - early colonisers to bridge?
A
- from strep dominated to a plaque dominated by actinomyces
- bacteria produce polysaccaride and these contribute to biofilm matrix
8
Q
Dental caries - Mature biofilm - diverse composition? Organisms reducing acidogenic potential?
A
Diverse composition: - facultative or obligate anaerboes - +ve bacteria (low pH non-mutans strep, mutants strep, actino and lactobacillus) Reducing potential (organisms) - veillonella app - S.sangius - S.salivarius - A.naeslundii
9
Q
Dental caries - Cariogenic features of dental biofilms bacteria - characterisitics?
A
- rapidly transport fermentable sugars
- conversion of sugar to acids
- maintain sugar metabolism under extreme conditions (low pH)
- prod of extra/intracellular polysacc
10
Q
Dental caries - S. mutans - absence and high level effects?important role?
A
Absence: - caries can develop High levels: - caries may not develop Important role: - role in caries initiation (lactobacillus for progression)
11
Q
Dental caries - Lactobacillus - type? characteristics? location?
A
- pioneer organism
- +ve non-spore forming rod (microaerophillic)
- colonise dorsum of tongue
- progression of caries
- established loss pH increases number of lactobacillus and reduces mutans
- contributes demineralisation of teeth once lesions established
12
Q
Dental caries - Oral actinomyces - characteristics?
A
Characterisitics:
- +ve non spore, rods and filament
- good plaque former
- ferment glucose and produce lactic acid
- A. viccosus and A. naeslundii (root caries)
13
Q
Dental caries - Summary of the microbiology of dental caries - overview? Ecological plaque hypothesis?
A
- S.mutans resident flora, but very low numbers (high in white spot lesions)
- S.mutans and Lactobacilli does not explain variation in caries experience
- Many acid-prod microorganisms and so no single organism can be attributed to caries
Ecological plaque hypoth: - consequence of changes in balance of resident microflora
14
Q
Dental caries - Intrinsic factors that influence tooth caries?
A
- Enamel composition
- Enamel structure
- Tooth morphology
- Tooth position
15
Q
Dental caries - Extrinsic factors that influence tooth caries?
A
- Saliva
- Diet
- Fluoride
- Immunity
16
Q
Dental plaque - resting pH? pH changes with sugar? rate changes?
A
Resting pH:
- 6.5 - 7
pH changes:
- falls to around pH 5 within 2-3 minutes of rinsing the mouth with sugar solution (20 mins to go back to normal)
Rate changes:
- speed in pH drop indicated of speed of plaque metabolism
17
Q
Dental plaque - how sugar reduces pH? Critical pH?
A
How sugar reduces pH:
- dietary sugars diffuse through plaque
- converted to lactic acid, acetic and propionic acids by bacteria
- pH could fall by 2 units in 10 mins
Critical pH:
- 5.5 is the lowest the pH can drop before demineralisation can occur
18
Q
Plaque - action of bacteria?
A
Action of bacteria:
- store glucose as glycogen (intracellular store)
- S.mutans synthesise other polymers given access to sucrose
- can synthesise extracellular polymers from simpler sugars
- increase plaque bulk and are more cariogenic
- glucosyltransferase break down sucrose into fructose and glucose, using this energy released to build glucose and fructose polymers
- glucans and fructans deposited extracell providing sticky environment for plaque organism
- ability of microorganisms to form plaque related to ability to synth polysacc
- control targeted at GST
19
Q
Dental caries - The effect of diet on caries - factors? sugars? sucrose?
A
Factors:
- plaque composition influenced by diet
- S.mutans greater with high sucrose diets
- lactobacilli is acid tolerant and found in greater proportions in carious cavities and deep layers of plaque exposed freq to sugars
Sugars:
- sucrose, glucose, fructose, maltose, lactose and galactose
Sucrose:
- affects the composition of early plaque, leading to higher numbers of bacterial species capable of synth glucan from sucrose
- plaque bulkier with sucrose-rich diet in comparison
- encourages dextran prod in plaque due to energy released (sucrose broken down into 2 monosacc)
20
Q
Dental caries - Substitutes to dietary sugars - effects? Xylitol?
A
- Non-sugar sweeteners are virtually non-cariogenic
- Xylitol though to prevent caries
- Sugarless gum prevent caries by stimulating salivary flow
Xylitol: - affects bacteria growth and metabolism
- affects de/mineralisation
- reduces biofilm form
- decreases S.mutans
21
Q
Dental caries - Oral pH change - on eating food item?
A
- Food item containing sugars, rapidly fermented by acidogenic bacteria, rapid acid production, plaque pH will fall
- other items eaten, before, during or after influence pH
- stimulates saliva (raising pH)
- remineralisation may be enhanced by Ca or fluoride (from food)
22
Q
Dental caries - Key factors for primary dentition caries?
A
- Sticky products are more cariogenic
- Sweetened pacifiers
- Sweetened drinks in bottles
- Prolonged breast feeding
23
Q
Fluoride impact on plaque and dental caries?
A
- High fluoride conc in plaque
- Fluoride favours precip of Ca and Pi
- Ca/Fl apatite encouraged
- Fl-apatite form part of development (if administered)
- Less soluble in acids more stable crystals
- Fl ions inhibit bacterial metabolism
24
Q
Dental caries - Substitutions in the hydroxyapatite crystals? Effect?
A
Main substituents of apatite: - HPO4, CO3 for PO4 - Sr, Ba, Pb, Na, K, Mg for Ca - F, Cl, Br and I for OH Ions present may influence ability of formation of dental caries - Fl inhibits cires - CO3 promotes carious attack
25
Dental caries - Demineralisation and remineralisation of the dental hard tissue - Saliva? dissolution?
Saliva:
- dilutes and budders acid (conc Ca and Pi ions)
Dissolution:
- more undersaturated the plaque fluid, with respect to hydroxyapatite, the greater tendency for dissolution of the enamel apatite
Between pH drops, remineral slowly occurs
26
Classification of Dental caries - site of attack?
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Pit and fissure:
- occlusal surface of pre/molars
- buccal and lingual surfaces of molars
- lingual surfaces of incisors
Smooth surface:
- below contact points (leads to cavitation)
- gingival third of buccal and labial surfaces (wide open cavity)
Root:
- exposed to environment
- reduced periodontium
- softened root surface
- shallow cavities
- may reach dentine
- hypermineralised surface
- brownish tissue
- loss of cementum (dentine caries can start)
Recurrent:
- around margins or base of existing restorations
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27
Classification of dental caries - rate of attack?
Acute caries:
- rapidly progressing
- all erupted teeth
- rapid coronal destruction (involvement of pulp)
Chronic caries:
- slow
- late pulp involvement
- pulp reaction (sclerosis or reactionary dentine)
Arrested caries:
- become static and show no tendency for further progression
- enamel; interdental lesions arrested when adjacent teeth lost (easier to clean)
- dentine; lesions with early sclerosis limit spread (stained brown colour)
28
Histopathology - enamel caries - name? shape? orientation? zones? characteristics?
Early lesion - white spot lesion:
- cone shaped with the base on the enamel surface
- apex pointing towards the amelo-dentinal junction
- different zones reflect different degrees of demineralisation
Zones:
- Translucent, Dark, Body and Surface
29
Histopathology of dental caries - Translucent zone?
Translucent zone:
- advancing edge of lesion
- more porous
- 1% of space (large pores)
- reduced Mg and CO3
- dissolution in interprismatic area (partial or totally missing)
30
Histopathology of dental caries - Dark zone?
Dark zones:
- 2/4% volumes of pores
- larger and smaller pores than translucent
- remineral due to precipitation of minerals lost from translucent zone
- narrow (in rapid)
- wider (in slow, more mineralisation)
31
Histopathology of dental caries - Body of lesion?
Body:
- 5-25% pore volume
- larger crystals than enamel
- water and organic materials replace lost materials
- prominent striae of Retzius
32
Histopathology of dental caries - surface zone?
Surface zone:
- little change in early lesion (no clinical appearance)
- more mineralised than enamel
- minerals from plaque and demineralised deeper layers
33
Enamel caries - histopathogenesis process?
1. subsurface translucent zone
2. enlarges and a dark zone develops in centre
3. Body of lesion forms in centre of dark zone (white spot)
4. Stained (brown)
5. Reaching the dentinoenamel junctions, caries spread laterally undermining adjacent enamel
6. Critical stage, enamel breaks forming a cavity (can happen earlier)
34
Histopathology of dental caries - fissure caries? white spot formation?
Fissure caries: white spot formation;
- caries forming on walls of fissure
- spreads outwards to adjacent enamels and downwards to dentine
- lesions meet at base of fissure
- cone shaped lesion with base at dentinoenamel junction
35
Histopathology of dental caries - dentine caries? contents? reaction? bacteria?
Dentine caries:
- living tissue respond to carious attack
- high organic content can be destroyed
- pulpal reaction before lesion reaches dentine
- demineralisation before bacterial front (bacteria break down organic matrix)
36
Histopathology of dental caries - dentine caries' zones?
- Sclerosis
- Demineralisation
- Bacterial invasion
- Destruction
37
Histopathology of dental caries - Zone of sclerosis? Key defining features?
Zone of sclerosis:
- similar to translucent zone
- beneath and sides of lesion (broader beneath)
- reaction from odontoblasts
- acceleration of peritubular dentine formation
- calcification of odontoblastic process
Key defining features:
- dead tracts
- death of odontoblasts
- air filled
- pulpal cells occlude tracts with hyaline calcified material
38
Histopathology of dental caries - Zone of demineralisation?
Zone of demineralisation:
- intertubular dentine is affected by acid wave
- acid diffuses ahead of bacteria
- soft dentine and sterile
- can't be distinguished by infected dentine
- stained yellow (bacteria)
39
Histopathology of dental caries - Zone of bacterial invasion?
```
Zone of bacterial invasion:
- bacteria proliferate within tubules
- tubular walls become soft and distended
- liquefaction foci
- beaded appearance
Two waves:
- acidogenic bacteria
- proteolytic organisms
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40
Histopathology of dentine caries - Zone of destruction? acute and chronic appearance?
Zone of destruction:
- increased number and size of liquefaction foci
- cracked appear at right angles of tubules (transverse clefts)
- cavitation
- acute (dentine very soft and yellow)
- chronic (brownish black colour and leathery)
41
Histopathology of dental caries - pulpal reaction? Tertiary dentine?
Tertiary dentine:
- variations in structure
- irregular (fewer tubules, poss atubular)
- varied mineralisation
- delay pulp involvement
42
Caries - Morphology of fissures - types?
Types:
- V and U type (shallow and selfcleansable)
- I and K type (Deep, narrow and retentive)
43
Root caries? Defintion? Demineralisation pH
- Root caries is a disease that is expressed as soft, progressive lesion found on a tooth root surface may has lost CT attachment and thereby has become exposed to the environment if the oral cavity
- pH (6.7)
44
Aetiology of root caries? Demineralisation pH? Factors? Microbiology? Diet?
pH: 6-6.5
Factors:
- less salivary flow, age, institutionalised, oral hygiene and number of teeth
Microbiology:
- strep mutans (coloniser) together with lactobacillus (root caries)
- strep sobrinus (combo mutans)
- strep sanguis (protective)
- actinomyces (a contradiction)
Diet:
- refined carbs and prevalence of root caries
- saccharose (higher pH 》 perio disease treated)
- decreased taste 》 increased sweets
Time
45
Root caries - active vs inactive? Clinical signs?
Inactive - well defined, dark brown, smooth/shiny surface, hard on probing, no plaque, possible cavitation
Active - yellowish, soft or leathery on probing, visible plaque, possible cavitation
46
Hellyer et al (1990) texture of lesions? Types?
Hard: as the surrounding tissues
Leathery: penetrated by new Ash 6 probe under mod Pa
Soft: easily penetrated by a new Ash 6 probe under moderate pressure with no resistance
47
Grading of root caries - Billings classification? Grades?
Grade 1: incipient
- soft texture, can be penetrated with explorer
- no surface defect
- light tan to brown pigment
Grade 2: shallow
- soft, irregular and drought texture, penetrated by a explorer
- 0.5mm depth surface defect
- tan to dark brown pigment
Grade 3: cavitation
- soft texture, penetrated by explorer
- penetrating lesion, cavitatuin present > 0.5mm, but no pulp involve
- light brown to dark brown pigment
Grade 4:
- deeply penetrating lesion with pulpal or root canal involve
- brown to dark brown pigment
48
Acute caries - Characterisitics? Vulnerable patients?
- rapid process (many teeth)
- lighter in pigment (light brown)
- pulp exposure and sensitive
- childhood/radiation caries
49
Chronic caries - characteristics?
- long standing involve (few teeth)
- no pain (usually secondary)
- decalcified dentine is dark brown and leathery
- small pulp chambers with addition dense tubular dentine in pulpal wall (tertiary dentine)
- significant degree of sclerosis
50
Arrested caries - charactersitics?
- static caries showing no further progression
- shift in oral conditions
- sclerosis of dentinal tubules and secondary dentine formation
51
Occult caries - what is it? Why is it a problem?
- a caries lesions that is located in a deep fissure of a molar, not showing clinical signs in the patient (can't see, need xray)
- a shock to a patient
52
Initial caries - defintion?
- demineralisation without structural defect
53
Superficial caries - defintion?
Enamel caries
54
Moderate caries - defintion?
Dentine caries
55
Deep caries - defintion?
Close to pulp
56
Complex caries - defintion?
Caries led to opening of the pulp cavity
57
Complexity - based upon?
Number of surfaces
Compound - 2 surfaces
Complex - greater than 2 surfaces
58
Black's classification of dental caries - class I -VI?
Class I - affecting pits and fissures on occlusal third and 2/3 thirds of molars and premolars, and lingual part of ant
Class II - prox. surfaces of molars and premolars
Class III - porx. surface of ant. without involving incisal angle
Class IV - affecting proximal surface of ant including incisal angles
Class V - affecting gingival 1/3 of facial or lingual surfaces of ant/post
Class VI - cusp tips of molars, premolars and canines
59
WHO system of caries classification? D1-D4?
D1: clinically detectable Evans lesion with intact surface
D2: clinically detectable cavities limited to enamel
D3: clinically detectable cavities in dentine
D4: lesions extending into the pulp
60
ICDAS II caries criteria - how to use? Restoartation codes (0-8)? Caries code (0-6)? Missing teeth (97-99)?
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How to use:
- a 2-digit code should be used, first of the restoration and sealant code and the sword is the caries code
Restoration code:
- 0 (not sealed or restored)
- 1 (sealant, partial)
- 2 (sealant, full)
- 3 (tooth coloured restoration)
- 4 (amalgam restorations)
- 5 (stainless steel crown)
- 6 (porcelain, gold PFM crown or veneer
- 7 (lost or broken restoration)
- 8 (temporary restoration)
Caries code:
- 0 (sound)
- 1 (first visual change in enamel)
- 2 (distinct visual change in enamel)
- 3 (enamel breakdown, no dentine visible)
- 4 (dentinal shadow, not cavitated)
- 5 (distinct cavity, visible dentine)
- 6 (extensive distinct cavity, visible dentine)
Missing teeth:
- 97 (extracted, caries)
- 98 (missing)
- 99 (unerupted)
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61
Diagnostic accuracy - sensitivity and specificity definitions? validity and reliability?
Sensitivity: TP/(TP+FN)
- probability that it indicates vaores when caries is truly present
Specificity: TN/(FP+TN)
- probability that it indicates no caries when caries is truly not present
Validity: correctness
- valid method results in measurement that measure the purpose of the measure
Reliability:
- .ethid that can be reproduced by another examiner getting the identical results
62
Visual-tactile caries examination - how to approach a caries?
Systematic (consistent)
Good light, clean and dry
Mirror and gentle probing (BPE)
Don't use sharp probe, can lead to cavitation
63
Fiber-optic transillumination - how to do it?
- light transmitted from an intense light source
- probe should be brought from the buccal ornlingal aspect at 45° to the proximal surface pointing apically, look for shadows in enamel or dentine
- if a shadow is seen from occlusal surface, may be associated with a caries
- low sensitivity
64
Tooth separation - what is it for?
- orthodontic elastic separator (2-3 days)
| - useful when deciding whether to treat radiographically observed dentine lesion operatively or non-operatively
65
Laser autofluorescence - DIAGNOdent? wavelength? Role? Values of measurement?
- infrared fluorescence of 655 nm for the detection of occlusal and smooth surface caries
Values of measurement:
- 0-13 (no care advised)
- 14-20 (preventive)
- 21-29 (preventive or operative depending on caries risk)
- >30 (operative care)
66
Radiographs - types?
- bitewing
- periapical
- OPG
- occulsal
- lateral
67
Caries-infected dentine - outermost layer of carious dentine - Appearance? Clinical signs? Treatment?
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Characteristics:
- outermost, irreparable, necrotic zone of destruction
Appearance:
- dark brown,soft, wet and mushy
Clinical signs:
- mineral component has dissolved away due to acid attack
- collagen matrix has been denatured
- bacterial load v high
- dentine tubular structure destroyed
Treatment:
- clinically removed
- no repair
- poor quality bonding substrate fornadhesibe material to achieve adequate seal
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68
Caries-affected dentine - inner layer of carious dentine - Appearance? Clinical signs? Treatment?
Characterisitics:
- inner layer of carious dentine which can be repaired by the dentine-pulp complex
Apperance:
- paler brien, harder, sticky and scratchy dentine
Clinical signs:
- mineral dissolution still occurs but lesser extent
- collagen still damaged by proteolysis but to a lesser extent so permitting dentine repair
- bacterial load lessens
- dentine tubular structure returns gradually within the depths of this zone
Treatment:
- deepest layer
- hypermineralised translucent dentine
- reparative reactions of the dentine-pulp complex
69
Prevention of dental caries - prevention and management techniques?
- risk assessment of child and family
- helping family manage dental care
- delivery for preventive care based on caries risk
- choosing from range of caries management available
- delivery of restorative care
- referral and recall
- management of dental neglect
- working with agencies for safeguarding
70
Prevention of dental caries - risk assessment of patient? Process?
- previous GA's and restorations in mouth
- siblings with family (diet)
- freq of radiographs
- education and motivation
- anxiety (least invasive strategy)
- infection
- ortho considerations
71
Prevention of dental caries - oral hygiene instruction?
- parental supervision between 7-8 depending on maturity
- no rinse after brush
- brush 2 a day with fluoride toothpaste
- pea sized tooth paste
- all children provided with personal oral health advice
- standard or enhanced prevention
- fissure sealants on perm molar teeth
- over 2, apply Ba fluoride varnish at least 2 a year
72
Prevention of dental caries - diet?
- diet diary be given for next visit
- over at least 3 days with 1 weekend
- drink water
- hidden sugars
73
Prevention of dental caries - dental caries?
- world's most common disease of children
- most common reason for GA's for children
- totally preventable with education, diet and brushing
- socioeconomic relation
74
Prevention of dental caries - getting it right for every child?
- wider social aspects of child health (housing conditions, government policies and funding)
- other health agencies
- childsmile
- SDCEP guidelines
- assessment of child needs if the personal care plan is to be effective in improving health
75
Prevention of dental caries - care plan?
- parent/carer motivation and responsibility
- patient history
- clinical exam
- caries risk
76
Prevention of dental caries - assessing the child and family?
- when child enters surgery
- make eye contact
- greet by name
- smile
- talk to the patient too
- gain support of parent and discuss how they can support and encourage child
77
Prevention of dental caries - factors to consider?
- intellectual, medial, mental, physical and other disabilities
- full medical, dental and social history (help assess motivation and health)
- if concerned contact child's school nurse, or GP
- dental neglect (child protection)
78
Prevention of dental caries - social history?
- overnight stays (toothbursh)
- parents work don't course problems with appointments
- GP practice name, school attended
79
Prevention of dental caries - clinical exam?
- visual inspection on clean and teeth
- radiographs if possible
- justify for radiographs in notes
- assess pain as priority
- look for sinuses if asympto
- cooperation is necessary to attend further appointments
80
Prevention of dental caries - assessing tooth brushing?
- clean 10/10
- plaque line around cervical margin 8/10
- cervical third of crown covered 6/10
- middle third covered 4/10
81
Prevention of dental caries - caries risk assessment?
- use of fluoride
- plaque control
- salivary quantitiy/quality
- medical history
- socioeconomic status
- dietary habits
- evidence of previous disease
82
Prevention of dental caries - scottish quintiles?
- SIMD - scottish index of multiple deprivation
- 1-3 relatively disadvantaged
- always use RA to form freq of review radiograph and freq of recall
83
Prevention of dental caries - behavioural management?
- tell show do, behavioral shaping and positive reinforcement, structured time, relaxation, and systemic desensitisation
- use of one or a combo of strategies to facilitate both preventive care and treatment
84
Prevention of dental caries - preventive strategies - explain well?
- consent, # of appointments, what is being done at each but prepared to modify is unable to accept some treatment or change in caries activity
- refer for relative analgesia for GA
85
Prevention of dental caries - develop individual action plan to encourage habit formation?
- identify convenient time
- identify a trigger as a reminder
- agree a date to review progress
- agree action plan with child and parent with a food and drink dietary and toothbrushing chart
86
Prevention of dental caries - encourage habit formation?
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Motivational interviewing
Explore current practices and attitudes
Gain empathy
Open questions
Affirmations
Reflective listening
Summarising
Elicit change
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87
Prevention of dental caries - brushing with fluoride?
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Under 3 - smear
Over 3 pea-sized
Caries RA
Standard 1000-1500 ppm
Increased risk 1350-1500 ppm
Over 10 2800 ppm
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88
Prevention of dental caries - chemotherapy?
- Cetuximab or denusomab long term
- Inflammation and ulveration of oral cavity and oropharynx major side effect particularly in radiotherapy
- Oral mucositis inhibit effective oral hygiene regimens die to pain and strong flavours
