Dental caries is an irreversible microbial disease of the calcifiedtissues of teeth ,characterized by demineralization of inorganicportion & destruction of organic substance of the tooth, whichoften leads to cavitation.The word caries is derived from the Latin word meaning ‘rot ‘ or‘decay’.
Dentinal caries may be considered as a disease of moderncivilization, since prehistoric man rarely suffered from this formof tooth destruction. Arthropologic studies of Von Lenhossek revealed thatdolichocephalic skulls of men from pre –neolithic period (1200B C) did not exhibit caries, but skulls from brachycephalic manof neolithic period (1200 -3000 BC) contained carious tooth.
•Isolated population that had not acquired dietary habits of modern ,industrialized man, retained a relative freedom from caries.•In East Greenland native prevailed everywhere except at tradingports where imported food was available . Pederson (1938) reportedthat 4.3% males living in isolated settlement of Angmagssalik hadcaries , as compared to 43.2% of comparable eskimo population livingat a trading ports.•On western parts of Greenland ,where contact with Europeantechnology was greatest, the percentage of male eskimos with carieswas 31.8% .
WHO records a global DMFT of 1.61 for 12 year old in 2004,areduction of .13% as compared to a DMFT of 1.7 in year 2001 WHO reported a DMFT score of 3.94 for India bin 2003 In India , data from the National Oral Health Survey (2002 -2003) states that in children aged 12 years old the cariesprevalence was 53.8% & the mean DMFT was 1.8 , where itwas 80.2 & 5.4 in 35 -44 year age of group.In 65-74 yr agegroup , the prevalence was 85% & mean DMFT was 14.9.
D the mean number of decayed teeth with untreated carious lesions M the mean number of teeth which have been extracted and aretherefore missing F the mean number of filled teeth DMF(T) to denote decayed, missing, and filled teeth DMF(S) to denote decayed, missing, and filled surfaces in permanentteeth dmf(t) dmf(s) similar indices for the primary dentition
A )EARLY THEORIESLegend of worms The earliest reference to tooth decay is probably from theancient Sumerian text known as ‘legend of worms’. It was discovered on a clay tablet , excavated from ancient citywithin Mesopotamian area, which dates about 5000B.C. The idea that caries is caused by worms was universal as it isevident from the writings of homer who made a reference toworms as the cause of tooth ache.
HUMORAL THEORY Advocated by Greek physicians , who proposed that caries iscaused by internal actions of acids & corroding humors & animbalance in these humors resulted in disease. The four elemental humors are blood, phlegm, black & yellowbile. VITAL THEORY This theory was advanced towards end of 18th century whichpostulated that tooth decay originated like bone gangrene , fromwithin tooth itself.
CHEMICAL (ACID ) THEORY Robertson (1835) proposed that decay was caused by acidformed by fermentation of food particles around teeth. PARASITIC THEORY In 1843, Erdl described filamentous parasites in the membraneremain from teeth. Findus in 1847 , also observed filamentous organism in enamelcuticle& in carious lesion. Dubos 1945 postulated that microorganism can have toxiceffect on tissue.
It was put forwarded by American Scientist W D Miller, statesthat caries is caused by acid produced by microorganism. He hypothesized that dental decay is chemoparisitic process;consisting of 2 stages:a) Decalcification of enamel & dentin as a primary step.b) Followed by dissolution of softened residue.
Significant observation of W D MillerOral microorganismDietary CHOAcidTooth enamelDental caries
Demerits Unable to explain the predilection of specific sites. Does not explain why some population are caries free. Does not explain the phenomenon of arrested caries.
Stephan showed that within 24 mnts of rinsing with a solutionof glucose / sucrose, plaque pH is reduced from about 6.5 – 5 &gradually returns to the original value within approximately40 mnts. This is known as Stephans curve.
In 1947 Gottlieb Organic/protein elements of tooth are initialpathway of invasion of microorganism. Enamel lamellae as pathway for microorganism in progress ofcaries.
PROTEOLYSIS CHELATION THEORYIn 1955 Schatz and Martin proposes that some of the productsof bacterial action on enamel ,dentin and food and salivaryconstituents can form chelates with calcium .A chelate is acomplex between an ion and two or more groups of complexingcompound. Since chelates can be formed at neutral or alkalinePH the theory suggested that demineralization of the enamelcould arise without acid formation.
AUTO IMMUNE THEORY In this theory, it is suggested that forbidden clones oflymphocytes attack target cells (odontoblasts) rendering thetooth vulnerable to caries attack.
According to anatomical site of the lesion• Pit and fissure caries• Smooth surface cariesbuccal and lingual surface cariesproximal surface Based on severity and progression• Rampant caries• Nursing caries• Radiation caries
Based on part of tooth structure involved• Enamel cariesincipient carieslinear enamel caries(odontoclasia)• Dentinal caries• Cemental caries based on activity• Primary caries• Secondary caries• Residual caries• Arrested caries
ETIOLOGIC FACTORS IN DENTALCARIESmicroorganismsHost&toothsubstratetimecariesThe four circle diagrammaticallyrepresent the parameters involved in thecarious process. All four factors must beacting concurrently (overlapping of thecircles) for caries to occur.
Dental caries is a multifactorial disease in which there is aninteraction between three principle factors.a) A susceptible host tissueb) Micro flora with a cariogenic potentialc) A suitable local substrate
TOOTH The morphologic characteristics of tooth have been suggested asinfluencing the initiation of dental caries Presence of deep,narrow,occlusal fissures or buccal and lingualpits tend to trap food, bacteria or debris Tooth position may play a role in dental caries, teeth which aremalaligned,out of position, rotated may be difficult to cleanseand tends to favor to accumulation of food and debris.
SALIVA It plays role in increasing the cariogenic effect on the teeth andas well it has the buffering action. Saliva has a cleansing effect also. A number of enzymes are isolated from the saliva, Ptyalin orAmylase is responsible for degradation of starch.
pH of saliva is determined mainly by the bicarbonateconcentration. pH increases with flow rate. Salivary components contributing to the ability of saliva toneutralize acid are salivary phosphate, salivaryproteins, ammonia, urea.
Viscosity of saliva is due to the mucin content. Some workers found out that high caries incidence is associatedwith a thick mucinous saliva. In addition it has antibacterial properties & haslactoperoxidases, lysozyme, lactiferrin, & igA.
The quantity of saliva secreted normally is 700-800 ml/day. The quantity of saliva may influence caries incidence as isespecially evident in cases of salivary hypoplasia & inxerostomia.
ANTIBACTERIAL PROPERTIESa. Lactoperoxidaseb. Lysozymec. Lactoferrind. igA
B.MICROFLORA WITH CARIOGENIC POTENTIALRole of microorganisms in caries Microorganisms are a prerequisite for caries initiation The ability to produce acid is a prerequisite for cariesinduction, but not all acidogenic organisms are cariogenic. Mainly the bacteria are Streptococcus Mutans,andstreptococcus sobrinus collectively known mutansstreptococci(MS)
C. A SUITABLE LOCAL SUBSTRATE-DIETDIET is defined as the types and amounts of food eaten daily byan individualNUTRITION is defined as the sum of the processes by which anindividual takes in and utilizes food. Physical properties of food and cariogenicityThe physical properties of food may be significant byaffecting food retention ,food clearance ,solubility and oralhygiene.
Physical nature of dietThe diet of primitive man consisted of a great deal ofroughage ,which cleanses the teeth of adherent debris duringmastication.in the modern diet soft refined food tends to clingtenaciously to the teeth and are not removed because of lack ofroughage. Carbohydrate content of diet Fermentable carbohydrates are on of the most importantcause of causing dental caries. Increase in the intake of refined carbohydrates are directlyproportional in causing the dental caries
Vitamin content of diet Vit. A &D is necessary for the development of the teeth. Vit K has the capacity of enzyme inhibiting activity in thecarbohydrate degradation cycle. Vit B complex ,Vit B6 has been proposed as an anticaries agent Calcium and phosphorous dietary intakeDisturbance in calcium and phosphorous metabolism duringthe period of tooth formation may result in severe enamelhypoplasia and defects of the dentin. Fluoride content of dietsome researchers believe that topical fluorides are moreimportant compared to systemic fluoride.
1. VIPEHOLM STUDYBy Gustaffson et al in 1954, & summarized by Davies in1955.Purpose of study ;To find out1) Does an increase in carbohydrate intake cause an increasein caries?2) Does an increase in carbohydrate intake produce a decreasein caries?
The institutional diet was nutritious , but contained littlesugar, with no provision for between meal snacks. The experimental design divided inmates into 1 control & 6experimental groups.1) A control group2) A sucrose group3) A bread group4) A chocolate group5) A caramel group6) An 8 toffee group7) A 24 toffee group
1. An increase in carbohydrate diet definitely increase the cariesactivity.2. The risk of caries is greater if the sugar is consumed in the form thatwill retained on the surfaces of teeth.3. The risk of sugar increasing caries activity is greatest, if the sugar isconsumed between meals.4. Upon the withdrawal of the sugar rich foods , the increased cariesactivity disappears.
1. The groups were made up from the patients in individualwards with no possibility of matching the age or initial cariesstatus.2. The patient were mentally challenged & did not alwaysfollow the instructions correctly.3. The dietary regimes of the various groups were changed inconsistent pattern.4. It is considered unethical to alter diet experimentally indirections likely to increase disease.
By Sullivan & Haris Harris -1963 The dental status of children between 7 to 14 yrs of age residingat hopewood house, New south wales was studiedlongitudinally for 10 yrs. All lived in a strict natural diet , with exception of occasionalserving of egg yolk, was entirely vegetable in nature & largelyraw. At the end ot ten year, 13 year old children had a mean DMFTper child of 1.6.The corresponding general was 10.7
The study was carried out by Turku , Finland.Aim of the studyTo compare the cariogenicity of sucrose, fructose & xylitolFindings of the studyAfter 1 year, Sucrose & fructose had equal carigenicity whereas xylitolproduced almost no caries
By second year; Caries had continued to increase in the sucrose group but remainunchanged in the fructose, whereas xylitol produced almost nocaries Xylitol was non cariogenic.
It is caused by the remarkably reduced levels of hepaticfructose- 1 – phosphate aldolase, which splits fructose -1-phosphate into two three-carbon fragments to be furthermetabolized. The ingestion of food containing sucrose / fructose causessymptoms of nausea, vomiting, malaise ,tremor & even comadue to fructosemia.
1. Sugar in solutions produces significantly less caries than solidsugar.2. Coarse particles of sugar are less cariogenic than fineparticles.3. Post eruptive maturation of teeth is greatly reduced in a highsugar environment.4. Addition of fluoride to the diet / drinking water causesreduction of caries.5. The sugar alcohols, xylitol & mannitol have no ability toinitiate or support caries.6. Phosphate addition of diet result in major reduction of caries.
The approach to preventing the development of dental caries isto establish & maintain good oral hygiene, optimize systemic &eliminate prolonged exposure to simple sugars in the diet. Primary preventive measures are aimed at reducing theoccurrence of new cases of caries in population. Secondary prevention aims at reducing the prevalence of caries. Tertiary prevention involves a treatment phase aimed atmaximum limitation of disability & maximum rehabilitation.
Vaccine is an immuno – biological substance designed toproduce specific protection against a given disease. The concept of vaccination against dental caries wasstrengthened because of; The transmissible & infectious nature of dental caries. The discovery & understanding of the secretory immune system.
It entails the introduction of a foreign molecule into the body,which causes the body itself to generate immunity against thetarget. This immunity comes frum the T cell & the B cellwith theirantibodies. Artificial active immunization is a process where the microbeare injected into the person so that they develop antibodies &become immune.
It is a process whereby pre-made elements of the immunesystem, such as antibodies are transferred to a person, & thebody doesn’t have to create these elements itself. It can be naturally acquired when antibodies are beingtransferred from mother to fetus during pregnancy.
Risk is defined as the probability that some harmful event willoccur. The importance of properly predicting the occurrence of lesion isobvious as targeted preventive actions can be directed to thosepersons having a high risk for caries & scares resources can beproperly utilized.
Assessment is highly indicated in populations where a largeportion is caries –free, but some individual are still highly cariesactive. Where resources are available to take care of these targetedpersons.
There are several factors & charectistics that accompany thedevelopment of an increased number of carious lesions, whichare helpful in caries risk assessment.Risk Indicators1. They are circumstances , which may indicate increased cariesrisk,
Examples :• Socially deprived, no work, bad economy.• Low knowledge, low educational of parents.• No regular dental check up.2. Factors related to general health which may indicate increasedcaries risk, Examples :• General diseases• Various handicaps
3. Epidemiological factors, which may indicate high caries risk, Examples :• Living in high DMF country• Living in high DMF area• Member of high DMF family
4 . Clinical findings which may indicate increased caries risk; Example ;• Newly erupted teeth• Exposed root surfaces• Crowded teeth
These factor may, depending on the dose & duration, indicatehigh or lower risk for caries. For eg: a large amount of plaque indicates high risk only ifpresent for a longer period of time.
It is a graphic model proposed by Bratthall D (1996) It illustrates the interaction b/w various factors such asdiet, bacteria & host susceptibility This illustrate the fact that caries can be controlled by severalmeans.
‘Caries risk’ is the term which indicate how muchdemineralization of cavities will occur in the future. The risk is expressed as ‘ % chance to avoid cavities’ A low % indicate high caries risk. High % indicate low caries risk. In addition to diet , bacteria & susceptibility a fourth factorcircumstances is also included. Chance to avoid of caries must be b/w 0 – 100%.it cannot be –ve or more than 100%.
Advantage;1. Affordable2. User friendly3. Easy to understand4. Tool to motivate patient5. Serve as a support for clinical discussion when selectingpreventive strategies for patient.
Since dental caries is a highly prevalent disease control of caries is aconcern of all the people. For a developing country like India, the focus should be on assessingthe caries risk & identifying those individuals at high risk to developcaries. Preventive measures can then be targeted at this group thereby notonly reducing the economic burden of the restorative care but alsoeliminating pain & improving the overall quality of life.