Cariology pp2 Flashcards
Dental caries is an _______ microbiological disease of the teeth that results in ______ dissolution and destruction of the ______ tissues.
Infectious
Dissolution
Calcified
What are 3 pathologic factors that “tip the scale” towards caries in The Caries Balance?
- Acid producing bacteria
- Sub-normal saliva flow/function
- Frequent eating/drinking of fermentable carbs
What are 3 pathologic factors that “tip the scale” towards NO caries in The Caries Balance?
- Saliva flow and components
- Fluoride - remineralization
- Antibacterials - CHX, xylitol
What does caries risk assessment evaluate?
A patient’s oral environment and helps determine the balance whether it is re-mineralizing or de-mineralizing
What are 4 clinical observation disease indicators measured in a caries risk assessment? (These tell us nothing about the cause of the disease only indicate presence of disease)
- Visible cavities present
- Caries restored in last 3 years
- Interproximal caries lesions/radiolucencies
- White spots on enamel surfaces
Name 9 main risk factors for caries risk
- MS and LB medium or high - by culture
- Visible heavy plaque
- Frequent (>3x) between meal snacks with sugar
- Deep pits and fissures
- Recreational drug use
- Inadequate saliva flow (< 0.5ml/min)
- Saliva reducing factors
- Exposed tooth roots
- Ortho brackets
3 reasons a patient could have reduced saliva flow
- Medication
- Radiation to head/neck
- Systemic Disease (e.g. Sjogrens)
Protective Factors
- Lives/work/school in a ______ community
- Fluoride toothpaste as least __-__ times daily
- ______ mouthrinse daily
- ____ppm F toothpaste daily
- Fluoride ____ in last 6 months
- Office topical Fluoride in last __ months
- ____ prescribed/used one week each of last 6 months
- _____ gum 4x daily last 6 months
- __ paste during last 6 months
- Adequate saliva flow - >___ml/min simulated
- Fluoridated
- 1-2
- Fluoride
- 5000
- Varnish
- 6
- CHX
- Xylitol
- MI
- 1 ml/min
6 Intake diagnostic data procedures
- Clinical exam
- Dental radiographs
- Bacterial Test
- Medical Hx
- Environmental intake - Dietary, Fl, Hygiene
- Saliva function test
When determining a risk level (Low, medium, high, and extreme), what are the 3 groups that you take into consideration?
- Disease indicators
- Risk factors
- Protective factors
Example pt - no disease indicators, one or more risk factors, and needs to increase protective factors. What risk level would you assign?
Medium
What risk factor will automatically put a patient in the extreme risk level?
Low saliva flow
Caries Management: The Medical Model emphasizes to not just fill the hole in the tooth. How is this done in 3 steps?
- Suppress the bacteria
- Control other factors that contribute to the disease process
- Change oral environment favoring remineralization
What risk levels would you suggest use CHX Antimicrobials?
High and Extreme risk -10ml/1 min @ bedtime 1 week each month
What risk levels would you suggest use xylitol gum/mints?
Moderate, high, and extreme risk patients
How often do low and moderate risk level patients need BWXrays?
Every 18-24 months (Periodic exams every 12 months)
Are sealants recommended for all risk levels?
All but low risk level
How often should you see an extreme risk level patient for periodic exams?
Every 3-6 months to re-eval for caries and apply fluoride varnish
How often is the bacterial test and saliva flow test done on a high risk level patient?
Every POE (periodic oral exam - which should be every 6-12 months)
2 types of streptococci involved in dental decay - Properties = aciduric, acidogenic, produces acetic/latic acids
- MS
2. S. sobrinus
What is the proposed window of time that shows the infectivity of acquisition of MS in infants?
19-31 months
How does xylitol interfere with transmission of S. mutans?
Blocks adherence
Patients with Frank Cavities - ___ or more frank cavities indicates high risk for future new carious lesions. ______ to high levels of mutans streptococci and _______. Patients have a high bacterial challenge that most likely can not be completely overcome by _____ alone. Placing restorations does not reduce ____ ____ in the rest of the mouth.
1 Moderate lactobacilli Fluoride Bacterial loading
Favorably altering the caries balance by intervention with CHX and F rinses successfully reduced caries risk status. Reducing caries risk status by chemical therapy markedly reduced the level of new caries. What does this confirm?
The “Caries Balance” concept
Enamel is made up of what mostly?
Dentin has more_____, ____, and ____ than enamel?
Carbonated hydroxyapatite
Protein, Lipid, and Water
What contains phosphoproteins and carboxlic acid amino acid residues?
Enamelins
What protein is mostly eliminated from mature enamel?
Amelogenins
In enamel, _____ surrounds every individual hydroxyapatite crystal
Protein
In mature enamel, what are the %s of protein and lipids by weight and volume?
Weight - 1%
Volume - 3% protein +lipid 50:50
Enamel rods are ____ to surface of tooth
Perpendicular
4 functions of saliva
- Antibacterial
- Clearance - clears carbs from plaque
- Lubrication
- Mineral exchange - buffering/re-mineralization
Normal simulated flow rate is what?
about 1 or more ml/min *
Stimulated flow rate of less than what, is a high risk factor for dental caries?
Less than 0.7ml/min
Inorganic components of saliva
- Calcium - remin/prevent demin
- Phosphate - buffer helps remin/prevent demin
- Potassium
- Sodium
- Chloride
- Bicarb - buffers, pH 6.8-7.3
T/F saliva is high in phospholipids
TRUE*
What 2 things do PRPs (Proline-Rich Proteins) do? Found in parotid and submandibular saliva
- Pellicle formation
2. Inhibits spontaneous precipitation of Ca by binding to it.
What is the name of the protein that is involved with pellicle formation and inhibits primary precipitation of Ca and PO$
Statherins
What protein is involved with pellicle formation, is antibacterial, and antifungal?
Histatins - parotid and submandibular saliva
What protein is involved with pellicle formation and has cystein protease inhibitory activity but found in the submandibular/sublingual saliva
Cystatins
What are the 6 main antibacterial salivary proteins?
- Lysozyme
- Lactoferrin- binds Fe
- Salivary peroxidase
- sIgA - inhibits attachment of S. mutans to tooth surface
- Amylase
- Mucins
What are 7 other components of saliva?
- Hormones
- Steroids
- Antibodies
- Growth Factors
- Cytokines and chemokines
- Nucleic Acid
- Drugs
The salivary pellicle is a thin film on the surface of the enamel. It begins immediately and forms within hours with multiple layers. What is it comprised of?
Strongly adsorbed specific PROTEINS and LIPIDS from the saliva
The pellicle is a protective layer on teeth, what are other functions?
- Lubrication
- Prevents demineralization
- Mineral storage needed for remineralization
What are 4 bad salivary effects?
- Pellicle formed allows bacteria to colonize on the tooth
- Provides a sticky surface
- Provides nutrients for a bacteria
- Precursor to plaque formation
_____ a population or community of bacteria living in organized structures at an interface between a solid and a liquid. Bacteria live in microcolonies encapsulated in a matrix of extracellular polymeric substances
Biofilm
What is the first bacterium to stick to the dental pellicle (PRPs) and grows very rapidly?
S. sanguis (“low colonization threshold” pH approx. 7, aerobic)
What enzyme does MS produce that helps enhance the adherence of bacteria to the pellicle?
glucosyl transferase
Up to what % of plaque is bacteria?
40%
4 reasons S. mutans is so cariogentic?
- Acidogenic
2, Aciduric (pH resistant) - Produce extracellular glucans
- Transport sugar
What bacterium is associated with early demineralization, higher concentrations at white spot lesions, sucrose sensitive, and prefers anaerobic
Mutans streptococci
Why are some Mutans Streptococci “heavily loaded”? (5 reasons)
- Diet
- Irregularities in enamel
- Other retention sites
- Heavy colonization of other family members
- Genetic and immunological factors
Can MS survive without teeth?
Yes colonize in furrows of tongue
Acids producing bacteria are usually less than __% of the total flora in plaque.
1%
Diffusion - acids produced by bacteria in the plaque diffuse rapidly through the plaque and into the enamel or dentin, travelling amongst the _____. After demineralization the dissolved ____ and ____ each diffuse out to the plaque. Diffusion occurs from a ____ concentration to a ____ concentration
Crystals
Calcium and Phosphate
High
Low
Cariogentic bacteria + fermentable carbs =
organic acids - which penetrate enamel and dentin, and dissolve tooth mineral
What percent of the crystal is carbonated hydroxyapatitie?
20% - it is more easily dissolved by acids
Which is most soluble in acid?
Carbonated apatitie
Hydroxyapatitie
Fluorapatitie
Carbonated apatite = dental mineral
What is the critial pH for enamel?
5.5
Carbonated hydroxyapatite(dental mineral)
+ organic acids(lactic, acetic, propionic, formic)
= ?
Demineralization - Ca/P into solution
Can caries lesion reach dentin without cavitation?
Yes - remineralization is still possible
Demineralization can be stopped by?
Fluoride in the solution between crystals, it inhibits mineral loss
What type of acid is more damaging than acid produced by bacteria?
Citric acid and HCL due to GERD
What does Ca/P do in the remineralization process?
Builds on existing crystal remnants and new mineral is less soluble - like a new fluorapatitie veneer overlying the original defective crystal
Systemically incorporated F has a _____ effect on solubility
Limited - F works primarily via topical mechanisms
What are 3 positive affects of topical F?
- Inhibits demineralization
- Inhibits plaque bacteria
- Enhances remineralization
F in solution at __ppm or greater markedly reduced the rate of dissolution of 3% carbonated apatite in acid buffer.
1 ppm - above 20-50ppm no further inhibition by F occurs
F cannot enter bacteria in its ionic form, but as the bacteria produce acid, ___ is formed which diffuses readily into the cells where it inhibits ____ activity
HF
Enolase
