Etiology 2. Local Factors / Dental Plaque and Calculus Flashcards
What is the sphere of influence
The area of bacterial influence
0.07 - 2.5 mm
Average 1.6
What is the glycocalyx
Matrix made in biofilm by micro-organism
Why are biofilms protective
- Barrier function
- Degrade Enzymes
- Repel negative charged agents
- Inhibit leukocyte phagocytosis
How do bacteria communicate
- Quorum Sensing: Changes gene expression
2. Autoinduction: Signal molecules
What are the 4 phases of bacterial growth
- Adherence - Glycoproteins deposited forms pellicle. Neg charge hydroxy attaches glycoprotein
- Lag - Plaktonic to sessile, Phenotype change, Lag in growth changes gene expression
- Rapid Growth - Dextrans and Levins laid down.
Co-Aggregate: Clump together in suspension
Co-Adhesion: Bacteria in saliva bind to bacteria in substrate - Steady State: In biofilm, Negligible 02, internat nutrient transfer, slow growth, Genes Shared, micorbes change as go deeper
- All Ladies Rightly Stare
How is subgingival plaque different from supragingival
Supra: Glycoproteins from saliva
Sub: Glycoproteins from GCF
What bacteria made epithelial cells
Spirochetes
What are the zones in ANUG
- Bacterial
- Neutrophil
- Necrosis
- Spirochete
What is the association between calculus and perio disease
Viable bacteria present on calculus
BUT Sri Lankan tea study proves calculus alone not cause disease
What are the mechanism of calculus development
Epitactic: Crystal seeding in matrix that enlarge
Booster: Increase pH cause precipitaion of calcium and phosphate
What are the 4 types of calculus
- Brushite
- Octacalcium Phosphate
- Magnesium Whitelocke
- Hydroxyapatie
How does calculus attach to cementum
- To cuticle
- Micro irregularities in surface
- Undercut in cementum
- Bacteria penetrate into cementum
What is the composition of calculus
Organic: Protein, Polysacch complex, Desquam Epi, Micro organism
Inorganic: Calcium Phos 75%, Calc Carbonate 3%, Magnesium phosphate
What is the prevalence of calculus
91% of population have supragingival
55% have subgingival calculus
What are the predisposing factors to periodontal disease
- Iatrogenic
- Margins
- Malocclusion
- Material
- Piercing
- Smoking
- 3rd Molar
- Radiation
- Xerostomia
- Anatomy
What causes cervical enamel projections
Amelogenesis does not stop before root development
What are the grades of CEP
- Points to furcation
- Approaches furcation
- Into furcation
What is the prevalence of CEP
28% - Man molars mostly
Prevalence of bifurcation ridge
70%
Run M/D
Man 1st molar most common
What is the attachment area of molars
Max: 30%, 20,20,20 per root Trunk, MD,P,DB
Man: 30,40,30 Root, M, D
Average distance of inter root separation
4-5 M/D
Wider the distance regen is harder
What is the effect of an overhanging restoration
Increase the sphere of influence
What is the average Bio Width
JE: 0.97 mm
CT: 1.07 mm
Total 2.04 mm
What is the average Bio Width
JE: 0.97 mm
CT: 1.07 mm
Total 2.04 mm
Root trunk length Max Molars
4 mm Max
Root trunk length Man Molars
3 mm Man
What is the size of furcation entrances
81% below 1 mm
58% below 0.75 mm
rate of root fusions
23% of the time
More common in females
What is material alba
Amorphous material of plaque and food debris
Why can’t biofilms be washed away
Glycocalyx high molecular weight particles that aren’t readily dissolved
Do bacteria need to be present for calculus to form
No - Glas and Gustafsson
When do you suspect a cemental tear
Isolated rapid bone loss
