Transcript of Chemical Plaque Control
- 1. CONTENTS Introduction History Terminology of agents Ideal
properties of antiplaque agents Criteria for usage of
antimicrobials Approaches to chemical plaque control Chemical
plaque control agents Conclusion References
- 2. INTRODUCTION Plaque control is the regular removal of dental
plaque and the prevention of its accumulation on the teeth and
adjacent gingival surfaces.
- 3. METHODS OF PLAQUE CONTROL Mechanical Chemical
- 4. CHEMICAL PLAQUE CONTROL Inhibition of plaque development
Elimination of existing plaque Inhibition of calcification of
plaque Inhibition of microbial colonization on tooth surfaces
- 5. History Ebers Papyrus 1500 BC: recipes for tooth powders and
mouthrinses 2700 BC: mouth should be rinsed with childs urine;
found in European writings beer, wine, honey, alum, vinegar
- 6. Hippocrates 400B.C. dentrifice. W. D. Miller, 1890
chemoparasitic theory. Sodium, potassium salts
- 7. TERMINOLOGY OF AGENTS European Federation of Periodontology
in the 1996 European Workshop on Periodontology recommended
Antimicrobial agents: chemicals that have a bacteriostatic or
bactericidal effect in vitro that alone cannot be extrapolated to a
proven efficacy in vivo against plaque. Plaque reducing/inhibitory
agents: chemicals that have only been shown to reduce the quantity
and/ or affect the quality of plaque, which may or may not be
sufficient to influence gingivitis and/or caries.
- 8. Antiplaque agents: chemicals that have an effect on plaque
sufficient to inhibit gingivitis and/or caries Antigingivitis
agents: chemicals which reduce gingival inflammation without
necessarily influencing bacterial plaque (includes
anti-inflammatory agents).
- 9. IDEAL PROPERTIES 1. Eliminate pathogenic bacteria only. 2.
Prevent development of resistant bacteria 3. Exhibit substantivity
4. Safe to the oral tissues at the conc and dosage recommended. 5.
plaque and gingivitis. 6. Inhibit calcification of plaque. ( Bral
and Brownstein 1988)
- 10. 7. Do not stain teeth or alter taste. 8. No adverse
effects. 9. Easy to use. 10. Inexpensive.
- 11. CRITERIA FOR USAGE OF ANTIMICROBIALS Substantivity: The
ability of an agent to be bound to the pellicle and tooth surface
and to be released over an extended period of time with the
retention of its potency minimal inhibitory concentration or
substantivity assay
- 12. pH and ion binding : ionic interactions between agent &
receptor sites retention of agent. pH of delivery vehicle state of
ionization of both agent & receptor site. Retention at low pH
due to ionization of acid receptor groups (carboxylate, phosphate
& sulfate). Bonesvol et al 1974
- 13. Stability : chemical breakdown or modification may occur
during storage, especially at elevated temperatures. Due to
intrinsic instability of agent presence of other formulation
excipients
- 14. Penetrability : For a drug to be effective, it must be able
to penetrate deep into the formed plaque matrix. Toxic safety : any
agent used for prevention or treatment of oral diseases must have
low toxicity.
- 15. APPROACHES TO CHEMICAL SUPRAGINGIVAL PLAQUE CONTROL 1]
Antiadhesive agents 2] Antimicrobial agents 3] Plaque removal
agents 4] Antipathogenic agents [Addy and Moran 1997]
- 16. Antiadhesive agents Pellicle surface to prevent the initial
attachment of the primary plaque-forming bacteria. Antifouling
agents Eg. Anionic polymers, substituted amino-alcohols,
polymethylsiloxane. too toxic or ineffective against dental
plaques
- 17. Antimicrobial agents Inhibit plaque formation 2 mechanisms:
Bacteriostatic Bacteriocidal Eg. Chlorhexidine
- 18. Plaque removal agents Chemical toothbrush Eg:
hypochlorites, enzymes Kornman 1986
- 19. Antipathogenic agents Direct approaches to alter plaque
ecology to a less pathogenic flora are restricted and have not yet
led to the development of agents appropriate for clinical use
[Cummins, 1992] Theoretically, all antimicrobial agents have the
potential to disturb the ecological balance of dental plaque
- 20. Bacterial succession plaque formation
- 21. CHEMICAL PLAQUE CONTROL AGENTS Based on antimicrobial
activity & substantivity Kornman 1986CHEMICAL PLAQUE CONTROL
AGENTS FIRST GENERATION Eg: antibiotics, phenol,quarternary
ammonium compounds & sanguinar SECOND GENERATION Eg:
Bisbiguanides,(chlorhexidine) THIRD GENERATION Eg: delmopinol
- 22. Based on groups (Newburn)
- 23. Systemic antimicrobials including antibiotics Bacterial
nature of plaque Not be used either topically or systemically as
preventive agents. Risk to benefit ratio is high. Bacterial
resistance and hypersensitivity Addy, Kornman 1986
- 24. Enzymes 1st group not truly antimicrobial agents, more
plaque removal agents- potential to disrupt early plaque matrix,
dislodging bacteria from the tooth surface. dextranase, mutanase,
protease. poor substantivity, mucosal erosions.
- 25. 2nd group enhance host defense mechanisms. Glucose oxidase,
amyloglucosidase.
- 26. Quarternary ammonium compounds Cationic surface active
agents. Structure central nitrogen atom linked to 4 alkyl groups by
covalent bonds. Net positive charge, reacts with negatively charged
cell membrane phosphates. More effective against Gm-ve.
- 27. Benzalconium chloride,cetylpyridinium chloride (0.05%) At
oral pH monocationic, adsorb readily & quantitatively > CHX
(Bonesvoll & Gjermo 1978) Low substantivity, 3-5 hours, loss of
activity once adsorbed or rapid desorption. No added benefits.
(Moran &Addy 1991)
- 28. Phenols & essential oils Both plaque inhibitory &
anti-inflammatory action due to anti-oxidative activity. Charles et
al 2004, 6 month study, equivalent effects as CHX without side
effects. pH is low (pH 4.3), erosion of dentine & enamel.
- 29. Triclosan nonionic antimicrobial, trichlora-2-hydroxy
phenyl ether. Simple solution, high conc 0.2%, dose (20mg
twice/day) moderate plaque inhibitory action substantivity of 5
hours. Activity zinc citrate, co-polymer polyvinylmethyl ether
maleic acid. Jackson 1997 > gingivitis compared to plaque
reductions anti-inflammatory.
- 30. Listerine - thymol, eucalyptol, methyl salicylate, benzoic
acid, boric acid in a hydroalcoholic base. Effective inhibitor of
plaque formation, development of gingivitis. High conc- cell wall
disruption Low conc- inhibition of bacterial enzymes
- 31. Siegrist et al no effect. Axelsson & Lindhe with
mechanical control. Positive effect. Long term trials efficacy of
Listerine is confirmed. (Lamster et al, 1983)
- 32. Natural products Sanguinarine Benzophenathridine alkaloid
derived from sanguinaria canadensis. Structurally related to
alkaloids. precancerous lesions upto ten folds, even after
cessation. Tea tree oil gingival inflammation Sookoulis &
Hirsch 2004
- 33. Metal salts Copper, Tin, Zinc Metal salt used, conc,
frequency of use. Polyvalent metal salts high conc, effective
Stannous fluoride difficult to formulate, hydrolysis in water Metal
salts + antiseptics
- 34. Oxygenating agents Disinfectants Hydrogen peroxide
supragingival plaque control. Peroxyborate acute ulcerative
gingivitis. (Wade 1966) Cleansing action- effervescence Undesirable
tissue changes
- 35. Detergents Sodium lauryl sulfate. Antimicrobial activity.
Plaque inhibitory action. Moderate substantivity 5-7 hours. Not
used alone.
- 36. Amine alcohols antimicrobial or antiseptic.
Morpholinoethenol derivatives- Octopinol antiplaque. Delmopinol
0.1%, 0.2 %. (Collaert et al, 1992) MOA interference with plaque
matrix formation, adherance of plaque forming bacteria
- 37. Chlorhexidine Developed in 1940s by Imperial Chemical
Industries, England Marketed in 1954 as antiseptic for skin wounds
Dentistry- Initially used for presurgical disinfection of mouth
& in Endodontics 1st definitive study (Loe & Schiott
1970)
- 38. 3 forms digluconate & acetate water soluble
hydrochloride sparingly soluble
- 39. Mechanism of action Dicationic nature ( 2 +ve charges on
either side of hexamethylene bridge) extremely interactive with
anions Relevant to its efficacy, local side effects, safety &
difficulty in formulation with other products Spectrum wide range
of Gm+ve & Gm-ve bacteria, some fungi, yeasts & certain
viruses like HBV & HIV (Wade & Addy, 1989)
- 40. Binds strongly to bacterial cell membrane Low Conc.
permeability leakage, potassium. High Conc Ppt bacterial cytoplasm
Death Readily absorbs to pellicle Persistent bacteriostatic action
lasting > 12 hrs. (Schiott et al 1970) Attaches to pellicle with
one cation , the other free to interact with bacteria trying to
colonize. (Jenkins, 1988)
- 41. Anionic substances, plaque inhibition effect of CHX, if
used shortly after rinses with the antiseptic. (Barkvoll et al
1989) Slow release from surfaces prolonged antibacterial
effect.
- 42. Toxicology, safety & side effects Brown discoloration
of teeth, restorations & dorsum of tongue Taste disturbance
(Salt) Lang et al 1988 Oral mucosal erosions Unilateral/Bilateral
Parotid swelling Increased supragingival calculus formation ppt of
proteins, pellicle thickness, inorganic salts. Bitter taste.
- 43. The mechanisms proposed for chlorhexidine staining 1.
Degradation of the chlorhexidine molecule to release
parachloraniline. 2. Catalysis of Maillard reactions. 3. Protein
denaturation with metal sulfide formation. 4. Precipitation of
anionic dietary chromogens. (Eriksen et al. 1985, Addy & Moran
1995, Watts & Addy 2001)
- 44. Anti-discoloration system (ADS) was launched=Europe A
clinical study supporting to show reduced staining had significant
drawbacks in design and presentation (Bernadi et al. 2004). A
laboratory study found no difference in staining potential (Addy et
al. 2005) plaque regrowth study showed significantly reduced plaque
inhibition for the ADS rinse (Arweiler et al. 2006). If it does not
stain it does not work.
- 45. The antibacterial mode of action of chlorhexidine The
bacterial cell is characteristically negatively charged. The
cationic chlorhexidine molecule is rapidly attracted to the
negatively charged bacterial cell surface, phosphate-containing
compounds. This alters the integrity of the bacterial cell membrane
and chlorhexidine is attracted towards the inner cell membrane.
Chlorhexidine binds to phospholipids in the inner membrane, leading
to increased permeability of the inner membrane and leakage of low-
molecular weight components, such as potassium ions
- 46. Antiplaque effect Any bacteria adhering to the tooth
surface are challenged by the chlorhexidine at the surface.
Depending on the bacterial species, and the amount of chlorhexidine
attached to the tooth surface, these microorganisms are either
killed (bactericidal effect) or are simply prevented from
multiplying (bacteriostatic effect).
- 47. The influence of the bacteriostatic effect will increase
over time as the concentration of chlorhexidine at the tooth
surface decreases, due to desorption into bacteria, saliva etc.
Plaque is prevented from forming because the bacteria attaching to
the tooth surface cannot multiply. The persistent, bacteriostatic
effect of chlorhexidine is what makes chlorhexidine the gold
standard
- 48. Delivery system Tooth paste Mouth rinse Gel Sprays
Varnishes Slow release vehicles
- 49. Clinical uses Plaque inhibition as an adjunct to mechanical
therapy & professional prophylaxis. Following oral surgical
procedures Intermaxillary fixation Physically/Mentally Handicapped
Medically compromised
- 50. Recurrent oral ulcers Orthodontic appliance Subgingival
irrigation. Denture stomatitis Preoperative rinse Oral malodor
High-risk caries patients
- 51. Povidine iodine 1811, Bernard Courtois Iodine 1880, Devaine
Bactericidal efficacy Late 1960s Povidine iodine
- 52. Structure of Povidine-iodine (PVP-I): Iodophor (Iodine +
Polyvinyl pyrrolidone {Povidine}) 10% of bound iodine PVP-I conc/
10 ability to dissolve in water & alcohol irritability &
staining
- 53. Spectrum & mechanism of Microbial destruction G+ve,
G-ve, fungi, mycobacteria, viruses & protozoans Bacterial
activity Amino (NH-), thiol (SH-), phenolic hydroxy (OH-) Schreier
et al- Transient / permanent pore formation loss of cytoplasmic
material & deactivation of enzymes Coagulation of nuclear
material
- 54. In vitro study, all tested strains susceptible to PVP-I
applied for 120 sec Bactericidal effect- low conc (0.1-1%)
- 55. Caufield et al
- 56. Side effects Staining teeth/ tissues thyroid dysfunction:
short-term Long-term Allergic to iodine Pregnant & lactating
mother
- 57. Should antiplaque agents be only used as adjuncts to
mechanical cleaning? Which vehicle? Which chemical?
- 58. CONCLUSION Plaque control is one of the key elements of the
practice in dentistry
- 59. References Newman MG, Takei HH, Klokkevold PR, Carranza FA.
10th edition. Carranzas Clinical Periodontology. Saunders Company
2006. 579-601 Clinical periodontology and Implant dentistry, 5th
edition, Jan Lindhe. Strategies and agents in supragingival I
chemical plaque control MICHELB RECX. Periodontology 2000, Vol. 15,
1997, 100-108
- 60. Chemical plaque control- prevention for the masses JOHN M.
MORAN. Periodontology 2000, Vol. 15, 1997, 109-117