Download Caries of teeth

Caries of teeth
Caries of teeth is a pathological process, which appears after eruption of teeth,
characterized by demineralization and softening of hard tissues of teeth with
subsequent formation of defect (cavitation).
Caries of teeth is the key problem of dentistry, very interesting in theoretical
and exceptionally important in a practical relation.
In obedience to the nomenclature of WOHP for the estimation of staggered of
teeth use three basic indexes a caries:
1. Prevalence of disease. It is an index, by the percent of persons, which have
the carious, stopped and remote teeth in that or other settlement, district,
city, area which is determined.
2. Intensity of defeat of teeth is determined a caries on the number of the
teeth staggered a caries. For this purpose the committee of experts of
WOHP for dentistry (1962) was offered for adults to use the index of CSR
(C is a carious tooth, S - stopped, R – a tooth is remote); for children with
a temporal or suckling bite - cs (c – carious, s – stopped); for children with
a variable bite – CSR+cs. To facilitate the comparative estimation of
morbidity a caries on the different contingents of the world, WOHP in
1980 year suggested to select 5 degrees of staggered depending on CSR for
children 12 years:
1) very low – from 0 to 1,1;
2) low – 1,2 – 2,6;
3) moderate – 2,7-4,4;
4) high – 4,5-6,5;
5) ever-higher – 6,6 and higher.
For the receipt of reliable information at determination of prevalence and
intensity of decay of teeth the groups of population must look around taking into
account age and floor, climatic geographical and socio-economic terms. Usually
children inspect in age 5-6, 12 years, 15 years, adults 35-44 and 65
years. The groups of ages of most models of population is 12- and 15- of children
of summers.
3. Increase of intensity or morbidity. Determined for the same person or
contingent through a certain term (1, 3, 5, 10 years). Difference in the value
of index between the first and second reviews and makes the increase of
intensity of caries.
By an epidemiology dental inspection it is possible to define prevalence and
intensity of basic dental diseases, quality of sanation of cavity of mouth, efficiency
of prophylaxis of caries of teeth and illnesses of paradontium, level of
the hygienical state of cavity of mouth, and also find out the necessity of every
caries of teeth, illnesses of paradontium and mucous cavity of mouth inspected in
treatment. Such inspection allows to work out an individual plan of medical and
prophylactic measures for every patient.
Statistical indexes of caries
Pursuant to the nomenclature of WOHP for the estimation of staggered of teeth by
a caries use three basic indexes: prevalence, intensity and increase of intensity of
caries.
Prevalence of caries is correlation amounts of persons (in percents), which have the
stopped and remote teeth carious, to the common amount of inspected. Prevalence
of caries in different age-old periods is different. The carious defeats are diagnosed
at children in age from 1-1,5 year. Under age 7-9 years prevalence of caries grows
to 95-100%, at children 11-12 years goes down to 70-80% as a result of physiology
change of teeth and forming of permanent bite. Beginning from 13-14, years
prevalence of caries grows again.
Intensity of caries (index of caries) is the amount of the carious stopped and remote
teeth in one inspected. At children with a temporal bite the index of caries is
marked as "cs" (carious, stopped), because remote temporal teeth are not subject to
the account. At children with a variable bite the index of caries is marked as CSE
+ cs (the staggered is taken into account by caries the both temporal and second
teeth). At children with a permanent bite the index of caries is reflected as CSE
(carious, stopped, extracted).
The indexes of intensity of caries at children vary in connection with influencing of
far of both external and internal factors. That is why WOHP suggested take into
account intensity of caries in 12-years-old children as basis for the estimation of
the state of hard tissues of teeth. At these children intensities of caries select five
levels:
1) very low (0-1,1);
2) low (1,2-2,6);
3) middle (2,7-4,4);
4) high (4,5-6,5);
5) ever – higher (6,6 and higher).
As index of intensity of caries next to the index of caries which takes into account
the staggered and remote teeth, an index which takes into account the amount of
the surfaces of teeth staggered by a caries is used — CSs. For determination of this
index the amount of staggered is counted up by a caries or the sealed surfaces of
teeth. This index more precisely represents the dynamics of carious process, that it
is especially important at determination of efficiency of prophylactic measures.
For an estimation exactly of these processes (loud speakers of development of
caries and efficiency of his prophylaxis) the index of increase of intensity –
caries is used. For this purpose determine intensity of caries (after the index of
teeth decay or after the index of caries of surfaces) at the same person or
contingent through a certain period (1-3-5 years). A difference in the value of
index between the second and first inspections makes the increase of intensity of
caries.
Theories of origin of caries of teeth
1. Miller’s chemically - parasite theory of caries (1884.). At one time this
theory was progressive, had confession and wide enough distribution. In
our time this theory of caries was fixed in basis of modern conception
of pathogeny of caries.
In obedience to this theory, carious destruction takes place two stages: a)
demineralization of hard tissues of tooth. Suckling acid which appears in the
cavity of mouth, as a result of milk sour fermentation of tailings of
carbohydrates of meal dissolves the inorganic matters of enamel and
dentine;
b) there is
destruction
of
organic
matter
of
dentine
by
the proteolytic enzymes of microorganisms.
Together with such factors, as microorganisms and acids, Miller
acknowledged existence of factors of contributory infringements. He
specified the role of amount and quality of saliva, factor of feed, drinkingwater, underlined the value of the inherited factor and terms of forming of
enamel.
2. Entin’s physical and chemical theory of caries (1928). Entin pulled out the
theory of caries on the basis of research of physical and chemical
properties of saliva and tooth. He considered that tissues of tooth were semi
penetrate membrane, which osmotic currents, conditioned the difference of
osmotic pressure of two environments which contact with a tooth, pass
through: blood from within and saliva outwardly. According to his opinion,
at favourable terms osmotic currents have centrifugal direction and
provides the normal terms of feed of dentine and enamel, and also hinder
operating on the enamel of external unfavorable factors. In same queue
centripetal motion of matters, that from the surface of tooth to pulp,
considered pathological and little direct connection with the diseases of the
nervous and endocrine systems, heredity, violation of mineral exchange,
terms of feed, way of life, labor, physiology mutual relations which result
in violation, in the system pulp – tooth – saliva. At unfavorable terms
centrifugal direction of osmotic currents relaxes and acquires centripetal
direction which violates the feed of enamel and facilitates operating on her
of harmful external agents (microorganisms), causing a caries. Negative
sides of Entin’s theory: did not know that at centripetal motion of matters
in an enamel took place feed of enamel by mineral salts from saliva, and
the method of exogenous prophylaxis of caries is thereon founded – on the
surface of enamel with the purpose of to fill up stocked coverage of teeth
by fluorine varnish , causing of remineralization matters (appliques) them
in an enamel – remtherapy; and also method of treatment of caries in the
stage of spot: appliques are on the staggered area of enamel
of remineralization matters.
3. Lukomskij’s biological theory of caries (1948). The author of this theory
considered that such endogenous factors, as a lack of vitamins D, B, and
also failing and wrong correlation of salts of calcium, phosphorus, fluorine
in a meal, absence or lack of ultraviolet rays violate mineral and albumen
exchanges. Investigation of it is a disease ofodontoblast, which at first
weaken and become inferior then. A size and amount
of odontoblasts diminishes that results in a metabolic disturbance in an
enamel and dentine. Demineralization comes at first then there is a change
of composition of organic matters. Negative sides of this theory: there are
not proofs, that odontoblasts is the trophic centers of tooth; a theory does
not explain the role of sugar in development of caries, localization of
carious defeats and prophylactic action of fluorine; it is not proved
that odontoblasts inferior at a caries. Even in a healthy contact tooth it is
possible to meet degeneration of odontoblasts as their atrophy.
4. Sharpenak’s theory (1949). Sharpenak explained reason of origin of caries
of tooth local impoverishments of enamel by squirrel as a result of their
speed-up disintegration and deceleration of resinthesis that certainly results
in the origin of caries in the stage of white spot. Deceleration
of resinthesis is conditioned absence or low maintenance of such amino
acid and reason of strengthening of proteolysis is a high temperature of
surrounding
air, hyperthyreosis,
nervous excitation,
pregnancy,
tuberculosis, pneumonia, accumulation of acids in tissues of organism (in
particular, at the insufficient entering organism of vitamins of group B,
plenty of acid accumulates in tissues) which results in strengthening of
disintegration of albumen. Cariogenic action of carbohydrates
of Sharpenak explains that at their large mastering the necessity of
organism rises in the vitamin of B1, which can cause avitaminosis and
strengthening of proteolysis in the hard substances of tooth. Negative sides
of theory: it was not confirmed experimentally, that at caries in the stage of
spot begins proteolysis albumens; an author underestimated the role of
microorganisms, local cariogenic factors, and over-estimated the role of
general factors.
5. Shatts’s and Martin’s proteolysis theory of caries (1956). Authors
explained perception of enamel to the defeat a caries stability of calcium albumens complexes. An enamel of tooth is the not negative structure of
organism, which through functional features mineralized more than other
tissues. Thus mineral and organic components of enamel are in close
biochemical connection. Firmness of the last can be broken at penetration
in the enamel of different active chemical agents, in particular proteolysis.
Development of carious process is examined in 2 stages: a) proteolysis, at
which a break of connections is between squirrel and minerals of enamel as
a
result
of
operating
of
bacterial proteolysis enzymes
on albuminous components; b) when destruction of mineral part of hard
tissues of tooth is from formation of complex connections of ions of metals
with acid ion of acids, salts of organic acids, amino acid, squirrel and
intermediate products of disintegration.
Negative sides of theory: presently there are not proofs of the first phase of
carious process for Shatts - Martin.
6. Platonov’s trophic nervous theory The author of this theory examined the
caries of teeth as trophic nervous process, which, according to his opinion,
develops only then, when the feed of hard tissues of tooth is violated.
By the basic Platonov’s pathogenic factor counted violation of the nervous
adjusting of trophic of dental tissues. However today known it is that teeth
with remote mash in time to 17 continue normally to function. Delete of
mash however much one of methods of treatment the complicated forms of
caries does not cause structural and functional changes in the enamel of
tooth, last continues to function as a valuable organ. The permanent dynamic
co-operating with a mouth liquid provides hard tissues of devitalized tooth
high mineralization which is answered by large acid proofness and structural
homogeneity.
The confessedly mechanism of origin of caries is making progress
demineralization of hard tissues of teeth under the action of organic acids
formation of which is related to activity of microorganisms.
In the origin of carious process take part great number of etiologic factors,
that allows to consider caries a proteolysis disease.
Basic etiologic factors is:
1) microflora of cavity of mouth;
2) character and diet, maintenance of fluorine in water;
3) amount and quality of saliva selection;
4) common state of organism;
5) the extreme operating is on an organism.
All above-stated factors were adopted cariogenic and subdivided into
general and local, such which act important part in the origin of caries.
General factors:
1) Inferior diet and drinking-water;
2) Somatic diseases, change in the functional state of organs and systems,
are in the period of forming and ripening of tissues of tooth.
3) The extreme operating is on an organism;
4) Heredity, stipulating the full value of structure and chemical composition
of tissues of tooth. Unfavorable genetic code.
Local factors:
1) Dental name-plate and dental deposit which is insulated microorganisms;
2) Violation of composition and properties of mouth liquid;
3) Hydrocarbons are sticky food tailings of cavity of mouth;
4) Resistance of dental tissues, conditioned a valuable structure and
chemical composition of hard tissues of tooth;
5) Rejection in biochemical composition of hard tissues of tooth and
inferior structure of tissues of tooth;
6) State of pulp of tooth;
7) The state of the tooth – jaw system is in the period of book-mark,
development and eruption of the second teeth.
At influence of cariogenic factors there are processes of demineralization in the
enamel of teeth, as a result a carious defeat the first stage of which is a hearth
of subsuperficialdemineralization develops is a «white spot» in an enamel.
Pathogeny
As a result of the frequent use of carbohydrates and insufficient care of
cavity of mouth cariogenic microorganisms are densely fixed on pellicle, forming a
dental deposit. At the use of sticky meal tailings of her harden in the retention
points of teeth (fissures, pits, contact surfaces, stopping, prosthetic appliances) and
added fermentation and rotting. On formation of dental deposit influence:
1) an anatomic structure of tooth and interrelation of him is with surrounding
tissues;
2) structure of surface of tooth;
3) food ration and intensity of mastication;
4) saliva and gingival liquid;
5) hygiene of cavity of mouth;
6) a presence of stopping and prosthetic appliances is in the cavity of mouth;
7) tooth – jaw anomalies.
A soft dental deposit has a porous structure which provides penetration inward of
his saliva of liquid components of meal. This soft amorphous matter, densely
adjoining to the surface of tooth. An accumulation in the deposit of the finished
goods of vital functions of microorganisms and mineral salts slows this diffusion,
as porosity disappears. And this already new matter is a dental name-plate, deleting
which is possible only violent, but also that is not fully. Under a dental name-plate
there is an accumulation of organic acids – milk, ant, oily and other. The last are
the products of fermentation sugar most bacteria in the process of their growth.
Exactly a basic role belongs to these acids in appearance on the limited area of
enamel of demineralized area. Neutralization of these acids does not take place, as
there is limitation of diffusion both in a dental deposit and from him.
There are streptococci in a dental deposit in particular Str. mutans, Str. sanguis,
Str. salivarius, which characteristic anaerobic fermentation is for. In this
process substance for bacteria mainly are carbohydrates, and for the separate
cultures of bacteria – amino acid. Leading role in the origin of caries taken
a saccharose. Exactly she causes the most rapid decline of pH from 6 to 4 for a few
minutes.
Especially
intensively
there
is
a
process
of glycolysis at hypomyxia, xerostomia, during sleep. And activity of process of
fermentation depends on the amount of carbohydrates which are attracted. It is set
that in the period of consumption of surplus the sugars amount of deposit is
considerably multiplied.
Composition of meal, its consistency, influences on formation of name-plate. It
is proved that a dental name-plate quick appears during sleep, than during a meal,
as saliva selection and mechanical action is instrumental in deceleration of
formation of dental name-plate.
The microorganisms of dental deposit are able to be fixed, raise on hard tissues
of tooth, metal, plastic, to product geteropolysugars, that contain different
carbohydrates –glicans, levans, dextrans, which a no less important role is taken:
1) glicans provide adhesion of bacteria with each other and by the surface of
tooth which conduces to growth and bulge of dental deposit.
2) Levans is energy and enormous amount of organic acids sources, high
adhesion own.
3) Dextrans also are product of enormous amount of organic acids which have
demineralization influence on the enamel of tooth due to good adhesion.
Research in the polarized light of cuts of enamel allowed describe the areas of
carious spot. Most deep area — transparent — appears because
of hypermineralization of enamel.
Silverstone (1973) described a carious defeat without formation of cavity,
zoning him depending on the degree of mineralization as follows: semilucent area
(front of spot); dark area, separating the body of defeat semilucent;
superficial intact layer.
The first area appears as a result of destruction of enamel as micropore or
micro spaces in area of scopes of prisms of enamels. Both periphery and core of
prisms dissolves in the body of defeat, pores are made by an from 5 to 25% volume
of enamel. It can spread on a small depth and go parallel surfaces or to proceed in a
depth fabric. External layer of enamel in depth to 30 mkm is here saved
practically intact.
On the surface of tooth the methods of optical and electronic microscopy are
reveal the followings organic educations: pellicle, deposit, microorganisms, loose
structures.Pellicle the subsuperficial layer of which penetrates on 0,1 mkm in the
crystalline layer of enamel is most intimately related to the tooth. The presence
of pelliclein 4 times reduces solubility of her on calcium. Moreover, the initial
caries of the stabilized form develops at presence of outward shell of tooth, without
her are carious defects on an erosive type.
On the early stages of carious defeat a bulge or making light, thinning
of pellicle, can be marked. There is opening of pores of enamel above a carious
hearth. In a number of cases separate prisms dissolve on a surface.
Modern knowledges about etiology of caries give the clear pictures of origin
of porosity, namely: to acid demineralization of crystalline structures of tooth
under influencing of organic acids, producted the microorganisms of dental nameplate. Conformities to the law of dissolution enamels, studied the methods of acid
biopsy, showed the primaryprimary output of calcium (so-called decalcification),
and then already phosphorus. Researchers explain it a presence in mineral
composition of enamel of four phases of phosphate of calcium, characterized
different solubility.
For clarification of the stages of pathogeny the models of caries, allowing to
get the artificial hearths of subsuperficial demineralization, were developed. So,
Miller (1883) placed remote teeth in mixture of saliva, chewed bread and meat
with addition of sugar and maintained them in a thermostat at the temperature
of 370 C during 3 months. Thus chalky spots appeared on the surface of enamel.
Presently researchers are use milk sour gel of pH 3,7—4,5. The most wide
distribution was got by a model, offered Silverstone (1969). On his method a tooth
is covered varnish, leaving a «window» on a surface, and immerse in solution
of oxideethilcellulosa, acidified to pH 4,5.
The design of caries is presently used also them on cuts of enamel in a 17%
gelatinous gel, acidified suckling acid to pH 4,3; containing 0,5 g/l of
synthetic gidroxideapatites. Structural likeness of caries of in vivo and in vitro is
shown, that allows widely use a design in the study of caries. At the design of
hearth
of subsuperficialdemineralization on
an
own
method
as
influencing substance attachment faction of saliva, acidified suckling acid to
necessary pH, was used (4,3—5,0). The use exactly of saliva is conditioned that in
her there are in an optimum concentration matters, providing in a norm the process
of remineralization enamel, including calcium.
Experimental a way it is set that for providing of the expected effect are
receipts of chalky spot — the action of every separate portion
of substance proceeds from 30 to 60 minutes. Thus the terms of development of
hearth of demineralization hesitate from 18 to 40 hours.
Mechanisms of hearth demineralization
The general picture of forming of hearth of demineralization appears as
follows: the first stage is a loss of calcium a tooth with
further remineralization. Demineralization is again established then. These
processes are alternated from a primary decalcification of enamel up to the visual
discovery of morphological signs of initial caries — chalk similar of the changed
areas, losers brilliance at drying of enamel. As a result of further influence they
meet in one hearth, forming a «white spot» in the beginning with a smooth surface,
and then and with rough.
Research in the reflected light and by the method of scanning electronic
microscopy of surface of enamel above a chalky spot, as a rule, did not expose
considerable differences from an intact enamel: she was covered organic
educations with scratches, furrows, unclear determined heads of prisms.
Considerably the greater volume of information about the structure of hearths
of carious defeat of enamel is got at research of cuts the method of interference
contrast. In thesubsuperficial layers of enamel carious hearths were revealed in the
form of cone, oval, wide and narrow bars. The body of defeat, surrounded a dark
area, was expressly determined usually. On a border with an intact enamel there
was a semilucent area of hypomineralization. A superficial layer was
practically intact. Destruction of prisms was revealed in the body of defeat a
different degree: from violation of clearness of their picture to fragmentation and
complete disintegration.
A semilucent area was characterized expansion of scopes of interprisms due to
dissolution mainly of periphery of prisms that was observed on all studied
standards. Thus on transversal motion of prisms cuts on scopes between
prisms micropores was revealed, and on longitudinal cuts — micro cracks. The
bodies of prisms collapsed rarer.
For the «white spots» of minimum sizes formation of typical areas is not
characteristic. The hearth of defeat is revealed strengthening of prism picture.
In a number of cases the areas of carious enamel differed from intact the
extended scopes of prisms in subsuperficial layers. The lines of Rettsius were
sharply contrasting and were dark uneven bars, formed the chain of micropore,
intervals in the partly blasted rows of prisms. Found out also micropores, opened
on a surface. Typical areas of caries on these standards not determined. Increased
lines of Rettsius in some approaching it is possible to examine as areas of chalky
spot, namely is alternation of dark and semilucentareas.
In other cases a superficial layer meets with the body of defeat under which a dark
area is well expressed or absent. In those cases, when a hearth was designed at the
low values of pH (<3,7), on standards destruction of superficial layer was marked
in combination with the subsuperficial hearth of demineralization.
Expansion
of microspaces
and
formation
of micropore in
a subsuperficial layer characteristically for the chalky spots of small sizes, and also
for the peripheral departments of all carious hearths.
The typical areas of caries, expressed in a greater or less degree, meet most
often — regardless of degree of maturity of enamel, intact superficial layer with
separatemicropores, dark area, surrounding the body of defeat, semilucent area
with the extended scopes of prisms and actually body of defeat with the expressed
destruction of prisms and porosity of enamel.
Combination of subsuperficial demineralization with partial destruction of
superficial layer of enamel is incident to the teeth of any age group at the action of
low index ofpH; this type is most unfavorable, as renewal of enamel becomes
impossible.
The pathoanatomical picture of superficial caries of enamel is presented two
basic areas: external is destruction of prisms; internal is demineralization of
periphery or core of prisms. An intact enamel is deeper disposed.
The caries of dentine is characterized the area of destruction of mineral
component, and also organic matter and by the layer of demineralization. In
addition, the brightly expressed protective layer of hypermineralization can be
formed in a dentine, and in mash is a reparative dentine.
Caries of cement is making progress destruction of surface of root of tooth,
developing as a result cariogenic operating of microorganisms on bare part of root.
Researches showed that 40—50% microflora of deposit makes actinomycoma. On
that ground a conclusion was done that along with streptococci surface of root
mushrooms render the pathogenic affecting.
The caries of root of tooth more frequent meets for seniors and old men,
having
expressed retraction
of gums,
characterized demineralization and
destruction of cement and dentine. Carious hearths can take shape (as knots)
rounded, oval or wrong, striking more frequent than all not one, but a few surfaces
and roots of tooth. Depth they are rarely exceeded by 1 mm.
An initial caries differs softening influence of cement, a defect is not revealed,
however characterized a surface is discoloration: discolored or, vice
versa, pigmented, acquiring the hazel, reddish tint of hard tissues, pliability at
sounding. Appearance of carious cavity is accompanied destruction of dentine on a
day and walls. As a result the tag of probe easily submerges in fabric of root.
The caries of cement can spread on the circumference of tooth, circular,
towards the apex of root or, vice versa, to enamel – dentine connection.
Development on a proximalsurface can flow without symptom up to an origin
pulpit.
The delete of dental deposits is instrumental in the visual discovery of the hidden
defeats of cement. The use of sharp probe allows define softening influence of
dentine and level of warm sensitiveness. Sciagraphy research — to diagnose
a proximal caries.
ACTIVITY DEGREES OF CARIES.
AGE
3–6
7 – 10
11 – 14
15 – 18
Тактика:
cs
CSE+cs
CSE
CSE
1-st DEGREE
2 –d DEGREE
3-d DEGREE
Менее 3
Менее 5
Менее 4
Менее 7
Exanination once
a year
3–6
6–8
5–8
7–9
Examination and
rehabilitation twice
a year
Более 6
Более 6
Более 8
Более 9
Rehabilitation 3 times a year.