Dental Deposits

Question 1

why does deposit matter

Answer 1

impacts oral health
impacts facial image
nutrient source for bacteria

Question 2

deposit types

Answer 2

soft deposits: food debris, materia alba, acquired pellicle, biofilm
hard deposits: calculus

Question 3

food debris

Answer 3

unstructured
nutrient source for cariogenic bacteria
usually removed with tongue of rinsing unless between teeth

Question 4

materia alba

Answer 4

cottage cheese
minimal adherence
unorganized structure
contains: salivary proteins/lipids, microorganisms, epithelial cells, leukocytes

Question 5

acquired pellicle

Answer 5

thin, acellular film, usually translucent
contains: salivary glycoproteins, macromolecules
protective layer
formation begins immediately
formed in 30-90 minutes
easily disrupted

Question 6

acquired pellicle significance

Answer 6

1. protection: against acids, remineralization and demineralization
2. lubrication: speech and mastication
3. biofilm formation
4. attachment of subsequent calculus

Question 7

biofilm

Answer 7

dynamic, non-mineralized
contains: microorganisms, polysaccharides, proteins
collects on moist oral surfaces
complex bacterial colonies and yeasts, protozoa, viruses
primary risk factor for gingivitis and dental caries
may cause oral malodor

Question 8

biofilm lifecycle

Answer 8

stage 1: attachment: bacterial cells attach to pellicle layer, easily removed
stage 2: multiplication and colonization: adhesion (irreversible attachment), coaggregation and growth upwards
stage 3: matrix formation: extracellular protective matrix for protection (proteins, glycolipids, DNA)
stage 4: biofilm growth: cell division and recruitment, diverse microbiome, cell to cell communication and signalling
stage 5: maturation/dispurtion: bacteria break free of attached biofilm, move from one localized area to another, cycle starts again in new area

Question 9

supragingival biofilm

Answer 9

bacteria gram positive aerobic rods and cocci with few motile species
diet and saliva is nutrient source

Question 10

subgingival biofilm

Answer 10

gram negative and motile bacteria
more associated with periodontal disease
bacteria invades the epithelial and connective tissue oft he periodontium
nutrient source is GCF and blood

Question 11

evolution of biofilm microorganisms

Answer 11

days 1-2: gram positive cocci, little inflammation, Streptococci mutans and Streptococcus sanguinis
days 2-4: cocci persist, more gram positive filamentous form and slender rods, grows into the cocci layer and replace them, addition of Actinomyces viscosus
days 4-7: mixed flora of rods, filamentous forms, and fusobacteria, biofilm thickens, greatest development at gingival margin and spreads coronally
days 7-14: vibrios and spirochetes, increase of gram negative and anaerobic bacteria, inflammation is visible
days 14-21: gram negative vibrios and spirochetes, gingivitis present, bleeding

Question 12

bacterial traits

Answer 12

health: gram positive, aerobic, non-motile
disease: gram negative, anaerobic, motile

Question 13

assessment and record of biofilm

Answer 13

location: supra or sub gingival
quantity: light, moderate, heavy or non-existent
extent: localized or generalized

Question 14

what is the most effective way to combat biofilm

Answer 14

physical disruption

Question 15

calculus

Answer 15

mineralized biofilm
hard tenacious mass
no living microorganisms, covered in biofilm
colour can range
builds up near salivary glands

Question 16

why are calculus deposits a problem

Answer 16

they provide the perfect surface for bacteria biofilms to form on

Question 17

calculus formation rate and mineral source

Answer 17

rate: forms after biofilm matures, 10-20 days, dependent on: salivary mineral content, hygiene, diet

mineral source: supra - saliva, sub - gingival crevicular fluid and inflammatory exudate

Question 18

calculus composition

Answer 18

70-80% inorganic components: calcium, sodium, magnesium, hydroxyapatite

20-30% organic components: desquamated epithelial cells, leukocytes, carbs, salivary mucins

Question 19

calculus attachment

Answer 19

acquired pellicle
irregularities in tooth surface
direct contact

Question 20

importance of calculus removal

Answer 20

difficulty in home care
rough texture attracts biofilm
promotes gingivitis and periodontitis
aesthetics

Question 21

stains

Answer 21

discolorations of the tooth that occur by:
-adhering to tooth surface
-pigmenting calculus or soft deposit
-incorporation in tooth structure or restorative material

Question 22

staining significance

Answer 22

aesthetics
evaluation of patient habits
rough surface can promote biofilm formation

Question 23

staining location

Answer 23

extrinsic: removable with scaling/polishing
intrinsic: cannot be removed with scaling, other interventions

Question 24

staining origin

Answer 24

exogenous: from external sources, tobacco stain, bacteria, foods
endogenous: from internal sources, tetracycline, pupal trauma, developmental conditions

Question 25

stain removal

Answer 25

prevention is best
use least abrasive polish and avoid excessive polishing