Secretions of the Oral Cavity and their Interactions on

Tooth Surfaces

“SALIVA”

*SALIVA - a watery substance secreted by the

salivary glands. It is composed of 95% water and

the remaining 0.5% are consists of electrolytes,

mucus, glycoproteins, cells, epidermal growth

factor, antibacterial compounds, & various

enzymes.

- In a healthy person, the amount of saliva that is

produced per day range from 0.75-1.5 liters and

during sleep, the amount may drop to almost zero.

- Its production is stimulated by both the

sympathetic nervous system (thicker saliva) and

the parasympathetic nervous system (watery

saliva). In humans, the submandibular gland

contributes around 70-75% of secretion, while the

parotid gland secretes about 20-25% and small

amounts are secreted by other salivary glands.

- Saliva production may also be pharmacologically

stimulated by so-called

sialagogues and suppressed by the so-called

antisialogogues.

FUNCTIONS:

-Lubrication

Saliva coats the oral mucosa therefore,

mechanically protecting it from trauma during

eating, swallowing, & speaking.

-Digestion

It moistens the food to help create a food bolus &

aids in breaking down food particles.

-Antimicrobial Effect

Saliva has a mechanical cleansing action, a

protective function against plaque build-up, &

microbial growth control.

-Buffering System

It contains supersaturated ions that keeps the

acidity of the mouth within a certain range,

typically at 6.2-7.4pH.

-Hormonal Function

Saliva secretes carbonic anhydrase which is

thought to play a role in the development of taste

buds.

“GINGIVAL CREVICULAR FLUID”

*GINGIVAL CREVICULAR FLUID - a fluid

occurring in minute amounts in the gingival crevice

believed by some to be associated with

inflammatory processes and not a product of a

healthy tissue since some of its components are

major contributors to the development of

periodontal disease (ex: cathepsin-K, interleukin-4,

interferon-gamma, leptin, osteocalcin, & alcaline

phosphatase).

- Composed of various enzymes, organic ions,

organic molecules, bacterial products, epithelial

cell (from tissue desquamation), PMN leukocytes

(Neutrophil granulocytes), lymphocytes, &

monocytes.

FUNCTIONS:

(+) Effects:

- clearance of cells and potentially dangerous

bacterial molecules.

- antibacterial action of immunoglobulins.

(-) Effects:

- induced plaque formation by calcium ions on the

gingival margin.

- tartar formation induced by alcaline phosphatase.

- proteolytic enzyme are dangerous for the gingival

sulcus and other gingival tissues.

“DENTAL PELLICLE”

*DENTAL PELLICLE - a protein film that forms

on the surface enamel by selective binding of

glycoproteins from saliva which protects the tooth

from acids produced by oral microorganisms after

consuming carbohydrates. These thin later forms

on the surface of the enamel within minutes of its

exposure & these glycoproteins, most especially

the proline-rich proteins, allow bacterial adhesion

on the surface.

“PLAQUE”

*PLAQUE - is an organized community of many

different microorganisms that are held together by

a matrix of extracellular polysaccharides which

triggers changes that make it increasingly difficult

to remove overtime.

SEQUENCES OF PLAQUE DEVELOPMENT:

DAY 1-2 >>> Gram (+) cocci (Streptococcus

sanguinis & Streptococcus mutans) 40-50% &

Gram (-) rods (Lactobacillus) 10-40% are the

microorganisms present in a dental plaque.

DAYS 2-4 >>> # of bacteria begin to increase by

replication and formation of colonies. Rods begin

to invade the area and start to replace the cocci.

DAYS 4-7 >>> most changes takes place here;

oxygen supply has decreased and anaerobic

bacteria appears. Filaments increase and more

mixed flora with gram (-) rods exist. Plaque near

the gingival margin thickens and develops mature

bacteria with spirochete & vibrios.

(Note: Dental plaque matures only if it remains

undisturbed for a period of time.)

DAYS 7-14 >>> mixed flora becomes more

evident; dominantly gram (-) vibrios & spirochetes.

At this period of time, presence of white blood

cells as a sign of inflammation, maybe found.

DAYS 14-21 >>> gingivitis may develop.

TYPES OF DENTAL PLAQUE:

1. SUPRAGINGIVAL PLAQUE - formation of this

plaque starts coronal to the gingival marginal and is

associated with caries & gingivitis when left

undisturbed. Most of the microorganisms in this

plaque are aerobic streptococcus and thus, receive

their nutrients from saliva.

2. SUBGINGIVAL PLAQUE - results from apical

progression of microorganisms in the supragingival

plaque which attaches to the root and pockets of

the epithelial lining (associated with the

advancement of periodontitis). Composed mainly

of anaerobic microorganisms that receives their

nutrients from the gingival crevicular fluid.

“CALCULUS”

*CALCULUS (tartar) - is a form of hardened

dental plaque. If plaque is not removed and

allowed to build up, it tends to harden after a few

days and form calculus. Calculus is made from

hardened (fossilized) anaerobic bacteria cemented

together with calcium phosphate salts from saliva.

It binds strongly onto the teeth, and forms a hard

cement-like cover with a rough surface. This rough

surface provides an ideal medium for further

formation. It usually accumulates around the base

of the teeth, under the edges of the gums, and

eventually deeper down in the sulcus, the space

between the gums and the teeth.

*Carbohydrates, Starches, & Sugars play a very

important role in plaque formation through a process

called "glycolysis". Bacteria in a person's mouth

convert Glucose, Fructose, & Sucrose into acids by

way of fermentation. If the concentration of these

acids, most especially, the lactic acid becomes high

enough, then it can cause the pH around the plaque to

drop below 5.5 and demineralization at that point will

occur.