龋病病因 (NXPowerLite).ppt

Etiology of Dental Caries
The four circles diagrammatically represent the factors involved in the carious four factors must act concurrently (overlapping of the circles)for caries to occur
Micro-
organisms
host
& tooth
Sub-
strate
caries
time
no
caries
no
caries
no
caries
no
caries
Host factor: saliva
What is saliva here mean?
a. major saliva glands
Saliva parotid, submandibular, sublingual
b. minor gland
c. gingival exudate
Why Saliva?
Animal experiments
Clinical observations
Animal experiment
Group No. hamsters Avg. no. Avg. caries
carious teeth score
Intact salivary glands 20
Desalivated* 10
* Parotid, submandibular, and sublingual glands.
Effect of desalivation on caries in hamsters
Clinical observations
Xerostomia:
decreased or lack of salivary secretion
Cause: therapeutic radiation
salivary glands disorder
(. sjogren syndrome)
taking medicine
Clinical observation
Caries in a patient with impaired salivary function as result of radiation therapy (courtesy of Drs Jansma and Vissink, RUG, herlands.
The caries is different mon. Decay offer seen in cervical area, a rapid demineralization over broad surfaces with no cavity. the huge change in quantity of saliva is responsible.
In xerostomia
The amount of bacteria
The quality of plaque change
, Lactobacillus, Yeast, Actinomyce
S. sanguis, Veillonella, Neisseria