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PD CH3 Saliva (Biofilm (Bioform formation (Adhesion of primary colonisers,…

- - - - Location on teeth
        
        Supra-gingival species
        
        Salivarius
        
        Anginosus
        
        Mutans
        
        Mitis
        
        interproximal
        
        sub-gingival
        
        Tannerella forsythia
        
        Campylobacter rectus
        
        Fusobacterium nucleatum
        
        Eikenella corrodens
        
        Prevotella intermedia
        
        Porphyromonas gingivalis
        
        Aggregatibacter actinomycetemcomitans
        
        Treponema spp
      - Oral biofilms
        
        groups of bacteria embedded in matrices attached to the surface
      - Composition
        
        15-20% microbial population
        
        Other than bacteria, non bacterial
        
        Yeast
        
        Protozoa
        
        Mycoplasma支原體
        
        Viruses
        
        Host cells
        
        Leukocytes
        
        Macrophages
        
        Epithelial Cells
        
        700 bacterial species are present in oral biofilm
        
        80-85% matrix containing
        
        extracellular polysaccharides
        
        protiens
        
        mineral salts
        
        Inorganic constituents
        
        Primarily
        
        Calcium
        
        Phosphates
        
        Traces
        
        Sodium
        
        Potassium
        
        Fluoride
        
        cellular material
  - - - gram-positive bacilli and cocci (S. Sanguis, Oralis,...) & growth
      - 2.Fusobacterium nucleatum joins in: facilitating adhesion by other bacteria (gram-negative, anaerobes...)
      - 3.Tertiary colonisers. Increased complexity: gram-negative, strict anaerobes
    - - Formation of acquired pellicle with salivary proteins on the enamel
- - - - microbial attachment
      - mineralization
      - lubrication
      - anti-bacterial role
    - - Saliva was biochemically analysed for specific single components
        
        polypeptides
        
        minerals
        
        enzymes
    - - beginning to map functional domains
        
        peptide synthesis
        
        recombinant approaches重組方法
  - - - lower concentration of solutes outside the cell than inside the cell
      - water will rush into the cell
    - - measure of solute concentration
      - defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L)
- - - - Post-eruptive maturation (Ca2+, F-, HPO42-)
      - Mineralisation equilibrium (Ca2+, F-, HPO42-)
  - - - carbonic anhydrase
      - Histatins
    - - Amylase
      - Mucins
      - Lipase
    - - Histadins
      - Proline-rich protein
      - Cystatins
      - Statherins
    - - Mucin
      - Statherins
    - - Mucins
      - Proline-rich protein
      - Satherins
      - Cystatine
      - Amylase
    - - Histaines
    - - Cystatine
      - Mucins
    - - Lysozyme
      - Cystatine
      - Mucins
      - Peroxidase
      - Amylase
  - - - Amylases
        
        In solution, it has antibacterial capacity vs. streptococci
        
        Adsorbed to tooth surface, they can promote adherence of these bacteria and digest starch to dietary maltose and production of acid
      - Statherins and acidic proline-rich proteins
        
        At enamel surface, they play an important role in mineralisation by inhibiting the formation of primary and secondary calcium phosphate salts.碳酸鈣
        
        When adsorbed to the enamel surface, they promote attachment of cariogenic 致齲的microorganisms
- - - - SUPRAGINGIVAL
      - SUBGINGIVAL
    - - Supra-gingival calculus
        
        Inorganic(70to90%)
        
        ✓75.9% calcium phosphate, Ca(PO4)2
        
        ✓ 3.1% calcium carbonate, CaCO3.
        
        ✓ Traces of magnesium phosphate,Mg3(PO4)2
        
        Traces of other metal
        
        sodium
        
        tungsten
        
        zinc
        
        , strontium
        
        , aluminium
        
        , silicon
        
        , copper
        
        , iron
        
        , manganese
        
        At least two thirds of the inorganic component is crystalline in structure.
        
        Electron microscopy & x-ray diffraction studies, 4 distinct phosphate crystals
        
        • Hydroxyapatite Ca10(OH)2(PO4)6 – approximately [58%]
        
        • Magnesium whitlockite Ca9(PO4)6XPO4 – [21%]
        
        • Octacalcium phosphate Ca4H(PO4)3.2H2O – [12%]
        
        • Brushite CaHPO4.2H2O – [9%]
        
        organic components(20to30%)
    - - Supragingival齦上 calculus
        
        the source of elements for supra-gingival calculus is saliva.
      - Subgingival齦下 calculus
        
        the gingival sulcus fluid and inflammatory exudate supply the minerals for the sub-gingival deposits.
      - Because the amount of sulcus fluid and exudate increases in inflammation, more minerals are available for mineralisation of subgingival plaque
    - - Salivary flow rate
        
        increased salivary flow rate decreases the calculus formation
        
        Salivary flow rate affects calcium phosphate saturation
      - Salivary calcium concentration
        
        Elevated salivary calcium concentration, increases the rate of calculus formation.
      - Higher total salivary lipid levels
        
        is associated with increased calculus formation
    - - BOOSTER’S CONCEPT
        
        mineral precipitation results from a local rise in the degree of saturation of calcium and phosphate ions which may be brought about in several ways礦物沉澱是鈣和磷酸根離子飽和度局部升高的結果，這可以通過多種方式實現
      - Salivary pH theory – Hodge & Leung 1950
        
        A rise in the pH of saliva causes precipitation of calcium
        phosphate salts by lowering the precipitation constant.
        
        pH may be also elevated by the loss of carbon dioxide, by the formation of ammonia by dental plaque and bacteria, or by protein degradation during stagnation
      - Enzyme
        
        esterase, present in the cocci, filamentous organisms, leukocytes, macrophages and desquamated epithelial cells of dental plaque, may initiate calcification by hydrolysing fatty esters into free fatty acids存在於球菌斑，絲狀生物，白細胞，巨噬細胞和牙菌斑脫落的上皮細胞中的酯酶可通過將脂肪酯水解為游離脂肪酸而引發鈣化
    - - Naeslund. Actinomyces and Leptotrichia are the important organisms in calculus.
        
        Leptotrichia usually formed a distinct, more superficial layer over the deeper Actinomyces colonies
      - Bulleid recognised the Leptotrichia buccalis in calculus
      - growth of these organisms produces certain biochemical changes that lead to a precipitation of calcium
    - - Visual Examination
        
        dark edge of calculus may be seen at or just beneath the gingival margin.
      - Gingival tissue colour change
        
        dark calculus may reflect through a thin margin and suggest its presence.
      - Tactile examination- (Clerehugh 1996)
        
        used WHO # 621 probe and a fine subgingival explorer is also used
    - - • Simplified calculus index (Green & Vermillion ’64 )
      - • Calculus component of periodontal disease index (Ramfjord 1959 )
      - • Calculus surface index (Ennever J,, Sturzenberger & Radike 1961)
      - • Calculus surface severity index (Ennever J et al ’61)
      - • Marginal line calculus index (Muhleman & Villa ’67)
      - • Volpe-Manhold index (Volpe A R & Manhold J H ’62)
    - - Supra-gingival calculus
        
        in "low hygiene" populations is associated with the promotion of gingival recession.
      - Subgingival calculus
        
        associated to a specific biofilm is the cause or result of periodontal inflammation. Research suggests that subgingival calculus, at a minimum, may expand the radius of plaque induced periodontal injury.
        
        , in "low hygiene" populations, is extensive and is directly correlated with enhanced periodontal attachment loss.
        
        impair re-attachment of ligament (no healing process)
- - - - decrease of
        
        Potassium
        
        phosphate
        
        cell proteins
        
        urea immunoglobulins
      - increase of
        
        Calcium
        
        sodium
        
        Chloride
        
        Bicarbonate
        
        secretory cell proteins
  - - - Spontaneous (sleeping): ~8 hr at 0.05 ml/min = 25 ml
      - Unstimulated (awake): ~12 hr at 0.7 ml/min = 504 ml
      - Stimulated (eating, talking): ~4 hr at 2.0 ml/min = 480 ml
      - 24 hour total = ~1009 ml [These are average values]
    - - 1800 drugs in 80 drug classes report this as a side effect
        
        Great variation in frequency and severity
        
        anti-depressives 抗抑鬱
        
        anticholinergics 抗膽鹼
        
        anti-hypertensive
        
        Opiates
        
        anti-histamine
        
        Multiple medication increase risk
        
        bronchodilators
      - No correlation with DRUGS (aging-related)
        
        Parotid flow does not decrease with age
        
        SM/SL, minor glands may decrease with age
      - Treatment and prevention
        
        Artificial saliva
        
        Poor substantivity實體性 (Need constant application)
        
        Can replace water and ions
        
        The protein-component is much harder to replace
        
        just placebo, not treating
        
        Gland repair or replacement
        
        Gene therapy and tissue engineering (experimental yet)
        
        Drugs to stimulate flow
        
        Depends on presence of functional gland tissue
- - - - Mg2+
      - H+
      - Ca2+
      - Na+
      - K+
      - Cl-
      - I-
      - F-
      - HCO3-
      - HPO42-
    - - Hormones
      - Lipids
      - Urea
    - - Dalton-weighted glycoproteins and peptides from glands
      - Products of B cells, PMNs, epithelial cells, bacteria
      - EX
        
        Proline-rich portions
        
        minerilization
        
        tissue coating
        
        Carbonic anhydeases 碳酸酐酶
        
        buffering
        
        Amylases
        
        digestion
        
        tissue coating
        
        anti-bacterial
        
        Peroxidases
        
        anti-bacterial
        
        Lysozyme
        
        antibacterial
        
        Lactoferrin
        
        Statherins
        
        mineralization
        
        lubrication &visco-elasity
        
        tissue coating
        
        Mucin2(MG2)
        
        digestion
        
        lubrication& visco-elasity
        
        tissue coating
        
        antiviral
        
        Histatins
        
        buffering
        
        mineralization
        
        anti-fungal
        
        saga
        
        Mucin1(MG2)
- - - - histatins
      - cystatins
    - - mucins
      - amylase
    - - Statherins
      - acidic proline-rich proteins
- - - - 2hr pellicle
        
        Granular structures which form globules, that connect to hydroxyapatite surface via stalk like structures
      - 24hrs later
        
        Globular structures get covered up by fibrillar particles: 500-900 nm thick
      - 36hrs later
        
        Pellicle becomes smooth and globular
    - - refers to soft accumulations of bacteria, food residuals and tissue cells that lack of organised structure when compared to dental plaque