Dental Plaque and Periodontal diseases 黃惠華1. LOE於 1965發表的 paper: “Experimental Gingivitis in Man”

Purpose(1) Produce gingivitis by withdrawing the oral hygiene

(2) Change of microbial flora

Method &

material

以 12 名 23 歲牙醫系學生做實驗對象，在良好的 oral hygiene 下測量之 PI 為 baseline，之後開始不清潔口腔，再檢查受試者之 GI 和 PI，並以抹片觀察細菌數量、菌種變化(bacterial study)。

Result

(1) 3 people < 10 days、9 people 15 - 21 days

(2) PI：0.43 - 1.67

(3) GI：0.29 - 1.05 a

Smear

(1) Initial: 90-100% G(+) cocci and rods

(2) 1-7 days: 50-70%

(3) Developed gingivitis: 45-60%

Discussion

(1) 短暫停止刷牙之後牙菌斑就開始形成 (2) 15-21 天造成 gingivitis

(3) Increase the age of plaque

(4) 移除牙菌斑可以改善 gingivitis

(5) Plaque—essential in the production of gingivitis

2. Dental deposits

Dental plaque 定義：bacterial aggregation on the teeth or other solid oral structure

形成：(1) Formation of dental pellicle coating of the tooth surface

(2) Initial colonization by bacteria

a. 主要為 G(+) facultative, e.g., Actinomyces viscosus, Streptococcus sanguis

b. Adhesins: fibrous protein (fimbriae) bind to proline-rich PT on dental pellicle

(3) Secondary colonization and plaque maturation

e.g., Prevotella intermedia, Prevotella loescheii, Prophyromonas gingivalis

Phase I (1 day) 80-90% G(+) cocci, rods

Phase II (2-4 days) Rods, filamentous, leptothix, Fusobacterium

Phase III (6-8 days) Vibrios, spirochetes

Rate of plaque formation: 1-30 days

- Maturation: multiplication and coaggreagation of bacterial species that do not initially colonize

tooth and gingival epithelial surfaces

- Coaggregation: stereochemical interaction of protein and CHO on bacterial cell wall

　e.g., (F. nucleatum + S. Sanguis/P. gingivalis), (P. loescheii + A. Viscosus)

位置：(1) Tooth surface, (2) Filling materials, (3) Crowns, (4) Orthodontic appliance, (5) Denture

飲食與 plaque formation：(1) Absence of food intakes

(2) Consistency of food: hard, friction, fibrous

(3) composition

組成：(1) Microorganism, (2) Epithelial cell, (3) Leukocyte, (4) Macrophage, (5) matrix

Plaque matrix

- 佔 plaque volume 25%

- 來源：a. Altered glycoprotein from saliva and crevicular fluid

b. Bacterial destransm levans and other sugar polymers

c. Bacterial metabolites and extracellular enzymes

d. Bacterial cell wall, cytoplasmic constituents

- 組成：a. Organic CHO(30%), protein(30%), lipid

b. Inorganic Ca, Mg, phosphorus

分類：Supragingival plaque Subgingival plaque

外觀 Gray, yellowish gray

位置 At or coronal to the gingival margin Apical to the gingival margin

biofilm Acquired pellicle cuticle

形成 Attached to gingival epithelial and tooth

surfaces (adhesion on pellicle mass growth

and maturation )

2-4 hours. Irreversible bactieral colonization

Attached to gingival epithelial and tooth

surfaces, but also loosely adherent within

the sulcus

菌種 Gram(+) facultative cocci Gram(-) anaerobic bacilli and spirochetes

(surface layer facing soft tissue contain many

motile spirochetes, “text-tube brush” form)

* 細分為 Attached zone / Unattached zone

* subgingival plaque 的菌種：Attached zone Unattached zone

G(+) G(-)

No extend junctional epithelium Contact with sulcular and junctional epithelium

Associated root caries, calculus, root resorption Periodontal pathogen

◎ Subgingival plaque, Tooth associated

(1) Cocci, fulamentous, fusiform

(2) May penetrate cementum

(3) Associated calculus, root caries, root resorption

◎ Subgingival plaque, epithelium associated

(1) Loosely adhere to junctional epithelium or in pocket lumen

(2) Mobile and G(-)

(3) May penetrated epithelium and CT

(4) Associate gingivitis and periodontitis

Material alba 定義：soft accumulation of bacteria and tissue cell that lack of organized structure of dental plaque

外觀：Yellow, grayish white soft sticky deposit

組成：Microorganism, desquamated epithelial cell, leukocyte, salivary of PT, lipids

特性：Less adherent → can be flushed away by water spray

Food debris (1) Dental plaque is not a derivative of food debris

(2) Not an important cause of gingivitis

Acquired pellicle 定義：an acellular, bacteria free, granular and heterogenous material coating of variable thickness

組成：derived from saliva and crevicular fluid, also from bacterial and host tissue cell products

鍵結：selective adsorption of environmental macromolecules electrostatic, van der Waals force

特性：(1) Thin pale during stain

(2) Mechanical cleaning to remove

(3) Reform on surface within minutes

Cuticle Primary: reduced ameloblast

Secondary:

(1) Remains of epithelium, attachment with deposit from gingival exudate (Frank 1970)

(2) Secretory product of adjacent epithelial cell (Schroeder 1977)

Calculus 定義：an adherent calcified/calcifying mass that forms on the surface of natural teeth/dental prosthesis

角色：(1) Always covered by plaque

(2) Keep plaque in close contact with gingiva

(3) Interfere the removal of plaque

(4) Contain bacterial toxic product

(5) Contributory factor

組成：Inorganic component (70-90%) Organic component

Ca3(PO4)2 75.9%, CaCO3 3.1%, Mg3(PO4)2

　(Ca 39%, PO43- 19%)

2/3 inorganic componenet is in crystalline

(1) Hydroxyapatite 58%

(2) Magnesium whitlockite 21% (posterior)

(3) Octacalcium phosphate 21%

(4) Brushite 9% (lower anterior)

(1) PT-polysaccharide complex

(2) Desquamated epithelial cell

(3) Leukocytes

(4) microorganism

Prevelance:

(1) supragingival calculus reaching a maximum at 25-30 y/o

(2) subgingivally no teeth without calculus by age 30

(3) increase with age

(4) Norway: molar and lingual of lower anterior teeth with 80% at teenage, no increase with age

分類：Supragingival calculus Subgingival calculus

外觀 White, whitish yellow Dark brown, greenish black

硬度 Hard, clay like Hard, flint like

黏性 Easy detach Firm attach

Mineral source Saliva Gingival fluid

位置 Maxillary molar (Stensen’s duct)

Mandibular incisor (Wharton’s duct)

Theory of mineralization of calculus

(1) Saturation of calcium & phosphate

　rise of PH (loss of CO2, formation of ammonia)

(2) Super-saturated solution

　Colloidal PT – supersaturated saliva stagnation – colloid settle out

Enzyme: organic phosphate → free phosphate ion by phosphatase

Fatty ester → free fatty acid by esterase, binding Mg, Ca

Rate of calculus formation:

(1) Mineral deposit of soft plaque: 1-14 days, 4-8 hours

(2) Calcifying plaque: 2 days – 50% mineralized; 12 days – 60-90%

(3) Daily increment: 0.1-0.15% of dry weight

Other factors:

(1) Fault dentistry:

　overhang of restoration, dental cement retained, poor designed prosthesis, surface roughness

(2) Food impaction

(3) Mouth breathing

(4) Toothbrush trauma

(5) Trauma from occlusion

(6) Smoking

(7) Systemic condition: DM

3. Microbiology of oral cavity

birth Oral cavity is sterile

6-10 hours Facultative flora, e.g., S. Salivarius

10 days Anaerobes in someone

5 months Anaerobe in most

tooth eruption Anaerobe in 100% (tooth eruption 提供 bacteria 無氧環境)

Preschool child Same as adult, except spirochete, P. melaninogenius (恆牙和乳牙 enamel 成分不一樣)

4. Microorganism in saliva

(1) 750 million per mm

(2) 組成：G(+) facultative cocci (streptococci 45%), fungi, virus, mycoplasma

5. Flora (healthy gingiva v.s. gingivitis)

Normal flora (healthy gingivae) Flora in gingivitis

Streptococci, Actinomyces (85%) (initial) Streptococci to Actinomyces

(gingivitis with bleeding) A. viscosus, bacteroids

Non-motile : motile = 40 : 1 GI: 3

G(-) P. intermedius, P. gingivalis P. gingivalis 31.8%

6. Pregnant gingivitis:

　P. intermedia, associated with estrogen, progesterone

7. Acute Necrotizing Ulcerative Gingivitis (ANUG)

　Treponema 32%,　P. melaminogenicus 26%, Selenomonas 6%, Fusobacterium 3%

8. Periodontitis

(1) G(-) anaerobes, motile

(2) Non-motile : motile = 1 : 1

(3) P. gingivalis 40%, Spirochetes 30%

(4) Attachment loss associate spirochetes

9. Flora associated early-onset form periodontitis

(1) Juvenile periodontitis:

　Actinobacillus actinomycetemcomitans, Haemophilusm, P. gingivalis, Fusobacterium nucleatum, Eikenella corrodens

(2) Child periodontitis:

　Fusobacterium, Selenomonas Wolinella, Capnocytophaga

10. Rapidly progressive periodontitis

　P. gingivalis, P. melaninogenius, Wolinella Haemophilus, Spirochetes