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DENTAL CARIES VACCINES

1DENTAL CARIES VACCINES. SUBMITTED BY Fathimathul Fairoosa.PCONTENTS..INTRODUCTIONVACCINESAPPROPRIATE IMMUNIZATION AGENTSEXPERIMENTAL DESIGNS AIMED FOR SALIVARY IMMUNITYEXPERIMENTAL DESIGNS AIMED FOR SYSTEMIC IMMUNITYROUTES OF VACCINATIONS PROBLEM WITH CARIES VACCINESPUBLIC HEALTH ASPECTSCONCLUSION REFERENCEDENTAL CARIES VACCINES INTRODUCTION It is well known the fact that prevention of disease is hundred times better than cure. Vaccination against tooth decay is an attempt to prevent dental decay. The development of tooth decay requires, a) Presence of cariogenic bacteria. b) A sugar in the diet which is metabolized by the bacteria to form acid.The process of caries development can be interfered by the presence of an effective immune response.

DENTAL CARIES ..

Vaccines???The word vaccine derived from latin word which means a suspension of attenuated or killed micro organism (bacteria;virus) administrated for the prevention or treatment of infectious diseases.It stimulate the production of protective antibody and other immune mechanism.More recent preparations are sub unit vaccines and recombinant vaccines.HOW IT WORKS.????The basis of a vaccine is that it keeps the patient in a state of readiness such that an infection does occur.The immune response which is more rapid and effective can be mounted,thus during the first response both B and T lymphocytes form MEMORY CELLS that later remember the earlier attack and respond much better.PRINCIPLES OF VACCINES.. ANTIGEN.An antigen has been defined as any substances which when introduced parenterally in to the body ,stimulates the production of an antibody with which it reacts specifically and in an observable manner.ANTIBODYAntibodies are immunoglobulins present in the plasma. TIME LINEMucosal immunization of infants before the appearance of first teeth study by CAUFIED et al- Window of infectivity children become permanently colonized by mutans streptococci between middle of second year & end of third year life If children does not acquire mutans streptococci by 26 months of age then unlikely that primary teeth will be colonized

Factors affecting window of infectivity; a)high maternal infection b)high dietary sucrose level children should immunize before window of infectivity

13MICRO ORGANISMMuch of the recent works on the bacteriology of dental caries suggest that the oral micro organism , particularly few strains of streptococci are important factors in the etiology of dental caries.The mouth appears to be an ideal place for a wide variety of antibacterial substances in the saliva.The activity of micro organism is greatly affected by the presence of these substances.

USES OF SPECIFIC ORGANISM..1)STREPTO COCCUS MUTANS.Facultative anaerobic organism producing extra cellular and intra cellular polysaccharides.It is found in the plaque of carious teeth.It cannot be isolated in the absence of dental caries.It can be grown in pure culture.Infection of germ free rats or normal hamsters with S.MUTANS has induce dental cariesThe organism can then be recovered from the carious lesion and grown in pure culture.

SALIVARY LEUCOCYTESGLUCOSYL TRANSFERASES(GTF)WALL-ASSOCIATED PROTEINS.DEXTRANASE.GLUCANS.LIPOPTECHOIC ACID.

WALL ASSOCIATED PROTEINSDEXTRANASEGLUCANSFound in gram positive bacteria.Exact role in dental caries pathogenesis is not clear

EXPERIMENTAL DESIGNS AIMED FOR SALIVARY IMMUNITYThese experiments were performed mostly in germ free rats

A) PERIGLANDULAR SALIVARY IMMUNISATIONB) IMMUNISATION BY COMBINED PERIGLANDULAR INJECTION AND INSTALLATION OF SREPTOCOCCUS MUTANS INTO THE PAROTID GLANDC) ORAL SUBMUCOUS IMMUNISATION PERIGLANDULAR SALIVARY IMMUNISATION SUBCUTANEOUS INJECTION OF S.MUTANS (SALIVARY IgA ANTIBODY) RATS SALVARY GLAND

REDUCED DENTAL CARIES

SALIVARY GLAND IMMUNIZATION BY COMBINED PERIGLANDULAR INJECTION AND INSTALLATION OF S.MUTANS IN TO THE PAROTID.Results in the formation of both salivary IgA and serum IgG and IgA antibodies.There was a reduction in the number of S.MUTANS on the teeth The serum antibody titres were much higher than those in saliva.This regime also leas t some functional impairment of the salivary gland.PARENTERAL IMMUNIZATIONKilled S.MUTANS were administrated to germ free rats in the drinking water for 45 days.A significant reduction in caries was related to an increased level of salivary IgA antibodies.IgA can be involved in the in the protection against cries has been involvEXPERIMENTAL DESIGNS AIMED FOR SYSTEMIC IMMUNITY.Mainly conducted in rats and rhesus monkey by using intra venous injection of live S.MUTANS.The rhesus model monkey has been developed to induce caries and to immunize the monkey in a way that would be acceptable in man because of the following features.

IMMUNIZATION ROUTESLOCAL ROUTESSYSTEMIC ROUTESLOCAL ROUTESTo avoid any systemic side effectsEstablished by passive immunization with IgG class of antibodies . These antibodies find their way from circulation to gingival crevicular fluids through gingival epithelium to reach the tooth surfaces.

SYSTEMIC ROUTESIngestion of S. MUTANS elicits predominantly a S- IgA response ,swallowing capsules containing S.MUTANS also increase in salivary IgA antibodies.Subcutaneous immunization elicit serum antibodies SYSTEMIC ACTIVE IMMUNIZATION.Ingestion of a vaccine containing killed S.MUTANS daily for 10 consecutive days induced increased level of specific secretory IgA antibodies. Resulted in reduction in number of viable S.MUTANS organism in dental plaque and whole saliva.Systemic passive immunization multivalent vaccine (s.mutans,serotype b,c,d,g). pregnant cow low plaque score (decreased no of streptococci in plaque) decreased caries activityThe sequence of cusp formation and calcification in the first permanent molars is comparable to that in man.The pattern and rate of caries in the decidious dentition is consistant with that found in man.The monkeys are fed entirely on a human type of diet.The immune response also parallel those found in man.

43ADVANTAGES OF VACCINATIONPrevent development of disease in children who show greatest incidence of dental cariesIt can be given at the same time of vaccination against diphtheria and tetanus.Immunity could be boosted thereafter at intervals to provide life long protection.Existing delivery system of immunization can be used with out additional financial burden being increased.LIMITATIONS IN DEVELOPMENT OF CARIES VACCINES.The formation of a lesion involves destruction of tissue ,does not bring the organism into contact with the immune system & consequently there is no stimulation of immunoglobulin synthesis.In dental caries some of the organism may combine by the immunogenic mechanism with the antibodies while others will share cross reacting antigens.On vaccination , the net effect will be a reduction of the antibodies available for reaction with S. MUTANS.An antibody may even promote back adherence by bonding to the tooth it will cause an increase in caries incidence. ROLE OF PLANTS.JULIAN .K.C.Ma reported that antibodies against dental caries can be produced in transgenic TOBACCO plant NICOTIANS TOBACCUM.HYATT and co-workers (1989) showed that tobacco plant can be used to access component antibody from immunoglobulin chains.. ADVANTAGES; -Capacity of producing full length antibodies to complement mammalian protein assembly;which can be used to produce antibodies with altered properties.

47ACTIVE IMMUNIZATIONThese includes : - use of synthetic S.mutans peptides - coupling S.mutans antigens to cholera toxin subunit - fusing S.mutans genes with a virulent salmonella - liposome delivery system48PASSIVE IMMUNIZATIONIncludes : a) monoclonal antibodies topically applied b) immune bovine milk c) egg yolk antibodies d) transgenic plant antibodyFACTORS MITIGATING FOR AND AGAINST THE POSSIBILITY OF DENTAL CARIES VACCINESFACTORS FOR A CARIES VACCINES:EFFICACY OF ORAL VACCINES.EFFICACY OF SYSTEMIC VACCINES.NEED FOR A VACCINE IN A SELECTED POPULATIONS.SAFETY OF ORAL VACCINES(NO SERUM ANTIBODIES)

FACTORS AGAINST A CARIES VACCINESLENGTH OF TIME FOR FDA APPROVAL.FINANCIAL RESOURCES.POSSIBLE LACK OF NEED IN POPULATION.PUBLIC HEALTH ASPECTS..An important questions always arises whether the research for caries vaccines is justified from a public aspect of views.In addition it appears that by using a combination of water fluoridation and weekly fluoride mouth rinsing ,reduction of 70 to 80 percent can be achieved.It is probable that caries vaccine could not be widely accepted by the general population.CONCLUSIONAlthough conclusive evidence is not forth coming there is optimism that such a vaccine will eventually be developed and there for , vaccination against dental caries is not a dead issue.research towards development of caries vaccine seems to be justfied from the public health point of view and though it is a difficult problem the issue as such, is relevent and highly vital.REFERENCEESSENTIAL OF PREVENTIVE AND COMMUNITY DENTISTRY-SOBEN PETERTEXT BOOK OF PEDIATRIC DENTISTRY-S.G DAMLETEXT BOOK OF PEDIATRIC DENTISTRY-SHOBHA TENDONTEXT BOOK OF COMMUNITY DENTISTRY-SATHISH CHANDRA AND SHAHLEEN CHANDRATHANK YOU