Dental Plaque
dense non-calcified mass of bacterial colonies in a gel-like intermicrobial matrix
Acquired Pellicle
amorphous organic tenacious membranous layer which forms over exposed tooth surfaces as well as restorations and dental calculus
What are the factors about dental plaque? (3)
1. major etiological factor in caries and perio disease
2. bacteria cannot initiate either disease or w/out plaque
3. plaque enables increased bacteria concentration at attachment site
Clinical appearance of plaque
Tooth=dull, dingy, slimy
Freshly deposited plaque=transparent or stained light brown or gray
Heavy, older plaque-matted, fur-like surface, usually stained (extrinsic stains)
Distribution of plaque
initially on proximal surfaces and cervical areas. Heaviest deposits on areas protected from cleaning (around crowding, proximal surface, lingual mand. molars)
Where do we see plaque occur?
On all teeth and on removable appliances
Always present before mineralization of calculus
Occurs over the surface of calculus deposits
Reccurence of plaque
cquired pellicle forms within minutes. disclosable plaque forms within 12-24 hrs after complete removal
Composition and structure of plaque
Early plaque-coccoid forms, then filaments
Structure-filamentous organisms at right angles to the tooth surface, helps to polarize more filaments
What is the source of plaque
Plaque is a product of bacterial growth
How does plaque attach
firm, adhering closely to the acquired pellicle over the surface of the tooth and removable appliances, attaches to irregularities in the tooth
Describe Pellicle formation
rapid and selective adsorption of certain glycoproteins from saliva. these proteins lose solubility, attach to tooth and precipitate acid. the glycoproteins are altered by enzymes from bacterial and oral fluids
Describe Bacterial Colonization
Initial attachment of bacteria to the pellicle by adsorption. colonized by gram+ streptococci in pits & fissures, gingival margins & interproximals, then bacterial multiplication occurs
Acquired Pellicle
Protection to the enamel of destructive acids
Nidus for bacteria to form plaque
mode of attachment for calculus
Materia Alba
Loosely adherent, unstructured white or grayish white mass of oral debris or bacteria which lies over dental plaque
Food debris
unstructured loosely attached particular matter, starts to degrade