Life Cycle of Dental Plaque Biofilm and Calculus

Tenacious, membranous layer that is amorphous, acellular and organic

Acquired Pellicle

Coats all surfaces of the oral cavity, teeth, soft tissues and oral prosthetics

Acquired Pellicle

Forms on the tooth within seconds-minutes after contact with saliva

Acquired Pellicle

3 Types of Acquired Pellicle

Surface Pellicle, unstainedSurface Pellicle, stainedSubsurface Pellicle

Pellicle that is clear, translucent and not readily visible

Surface Pellicle, unstained

Pellicle that can take on extrinsic stain

Surface Pellicle, stained

Pellicle that is continuous with surface pellicle but is embedded in the tooth structure, particularly where the tooth is demineralized

Subsurface Pellicle

4 Significance of Pellicle

1. Provides a barrier against acid2. Lubrication3. Nidus (home) for adherence of microorganisms4. Supplies nutrients for bacterial plaque to colonize and mature

Dense, non-mineralized complex mass of colonies in a gel-like intermicrobial matrix

Dental Plaque Biofilm

Adheres firmly to acquired pellicle, contains up to 700 bacterial species, yeasts, viruses and protozoa

Dental Plaque Biofilm

Bacteria in saliva involved in making plaque biofilm attach to the ___________

acquired pellicle

Streptococci break down __________ in the acquired pellicle producing _________

polysaccharides; glucans

__________ are sticky, which help adherence to the acquired pellicle

Glucans

For plaque to mature, it must remain _______

undisturbed

Two bacteria that dominate the dental plaque

Streptococcus sanguisStreptococcus mutans

Which bacteria causes caries?

Streptococcus mutans

Describe the plaque microorganisms in Day 1-2

Gram (+) cocci 40-50%Gram (+)rods 10-40%

Days 2-4

# of bacteria begin to increase, rods begin to invade the area and start to replace the cocci

Days 4-7

Most changes take place here; filaments increase and more mixed flora with gram (-) rods

Plaque near gingival margin thickens and develops mature bacteria with spirochete and vibrios (what days does this happen?)

Days 4-7

Oxygen supply has decreased and anaerobic bacteria appear (what days does this happen?)

Days 4-7

Describe days 7-14

mixed flora more evident; dominantly gram (-) vibrios and spirochetes

In what days will you find the presence of white blood cells (a sign of inflammation)?

Days 7-14

In what days do we see gingivitis develop?

Days 14-21

During plaque attachment pH level drop from ___ to ___

7 to 4

Enamel demineralization begins at a pH of _____

4.5 to 5.5

Inorganic and organic solids make up what % of the base composition of dental plaque biofilm

0.2

Water makes up what % of the base composition of dental plaque biofilm

0.8

Which plaque is coronal to the gingival margin and is associated with caries and gingivitis?

Supragingival plaque

Most of the microorganisms in this plaque are aerobic streptococcus and receive nutrients from saliva

Supragingival plaque

Formation of this plaque starts at the gingival margins and increases rapidly when left undisturbed

Supragingival plaque

This plaque results from apical progression of microorganisms in the supragingival plaque

Subgingival plaque

This plaque attaches to the tooth, root and pockets of the epithelial lining

Subgingival plaque

______ plaque in the pocket are mainly anaerobic and receive their nutrients from the gingival crevicular fluid

Floating/unattached

3 Organizations of Subgingival Plaque

1. Tooth surface attached plaque (tooth associated plaque)2. Epithelial associated plaque3. Unattached (floating) plaque

Which type of subgingival plaque is associated with the advancement of periodontitis?

Epithelial associated plaque

Which type of subgingival plaque can be removed with a water pick?

Unattached (floating) plaque

Which solids make up the inorganic composition of biofilm?

Calcium, phosphorus, and fluoride

Which solids make up the organic composition of biofilm?

carbohydrates and proteins