Lec. 2
‫سهى محمد سامي حسن‬.‫د‬
‫ – جراحة الفم والوجه والفكين‬-‫ماجستير‬
Etiology of periodontal diseases.
The reasons why gingivitis was established or
why gingivitis develops into periodontitis ?
are still incompletely understood .
It appears that:
1. the proliferation of pathogenic microorganism .
2. their toxic potency .
3. their capacities to invade tissues .
4. Individual host response .
Gingivitis is completely reversible
periodontitis is only partially reversible .
Gingivitis and periodontitis is due to a
multifactorial diseases .
1. pathogenic microorganisms which is the
primary etiological factor for existences of Gingivitis
and periodontitis .
2. heredity the genetically determined non – specific
and specific immune responses as well as systemic
syndromes and diseases influence the existence and
the clinical course of periodontitis .
3. Habits and the patient s own approach to general
health will influence plaque formation and host
response , both systematically and particularly with
regard to oral health .
4. Social circumstances influence the systemic and
psychic well being of the patient .Problems in the
socioeconomic arena lead to negative stress .
5. Psychic burdens and stress influence the immune
status .
Experimental gingivitis model:
From day 0 on when mechanical plaque , control was
stopped , plaque will slowly form on the teeth ,with
the time the plaque composition changes , with a
shift to more gram – negative species and more
rods ,film filaments, and from day 7 on , spiriles and
spirochetes from day 3 on , the first symptoms of
gingival inflammation become visible . When proper
plaque control is reestablished , the plaque
composition returns to the initial situation ,and the
symptoms of gingivitis disappear .
Gram + positive microorganisms
1. streptococcus . S. anginosus
S. milleri
S. mutans
S. sanguis
S. oralis
S. mitis
S. intermedius
2. Acinomyces A. naeslundii
A. viscosus
A. odontolyticus
A. israelii
3. Propionibacterium
4. Rothia
R. dentocariosa.
5. Lactobacillus . L. oris
L. salivarius
L. buccalis
Gram – negative microorganisms
1. Neisseria .
2. Branchamella .
3. Actinobacillus .
4.Haemophilus .
5. Bacteroides .
6. Fusobacterium.
7. Campylobacter .
acute necrotizing ulcerative gingivitis .
Candida albicans
Entamoeba .