The earliest reference to tooth decay and pain came from an ancient Sumerian text known as the 'Legend of the Worms', which described toothache being caused by a worm drinking the blood of teeth and feeding on the roots of jaws. Since then, theories on the causes of dental caries have included humoral theory proposed by Greek physicians, chemical/acid theory involving acids formed by food fermentation, and microbial theory recognizing the role of bacteria. Current understanding is that dental caries is a multifactorial disease requiring the presence of bacteria, fermentable carbohydrates in the diet, and susceptible tooth structures, as well as factors like saliva, plaque, and oral hygiene.

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12. THE LEGEND OF THE WORMS
• EARLIEST REFERENCE TO TOOTH DECAY & TOOTH PAIN CAME FROM ANCIENT SUMERIAN TEXT KNOWN
AS THE ‘LEGEND OF THE WORMS’
• TOOTHACHE – A WORM THAT DRANK BLOOD OF TEETH & FED ON ROOTS OF JAWS
• DISCOVERED ON A CLAY TABLET NEAR
NIFFER, UR & OTHER CITIES IN
EUPHRATES VALLEY OF LOWER
MESOPOTAMIAN AREA (5000 BC)
• REMEDY READ AS FOLLOWS: “ MIX
BEER, THE PLANT SA-KIL-BIR AND OIL TOGETHER, REPEAT THEREON THE INCANTATION THRICE (AND)
PUT IT ON HIS TOOTH”

13. HUMORAL THEORY
• GREEK PHYSICIANS – 4 ELEMENTAL HUMORS ARE:
BLOOD – SANGUINE
PHLEGM – PHLEGMATIC
BLACK BILE – MELANCHOLIC
YELLOW BILE – CHOLERIC
• GALEN – ‘DENTAL CARIES IS PRODUCED BY INTERNAL ACTION OF ACID & CORRODING HUMORS’.
AN IMBALANCE RESULTS IN DISEASE

14. • AT THE END OF EIGHTEENTH CENTURY UP TO MIDDLE OF NINETEENTH.
• DENTAL CARIES – ORIGINATED IN TOOTH ITSELF LIKE BONE GANGRENE
• CARIES IS CHARACTERIZED BY EXTENSIVE PENETRATION INTO DENTIN, EVEN TO PULP

15. CHEMICAL(ACID) THEORY
• ROBERTSON (1835): DENTAL DECAY – ACID FORMED BY FERMENTATION OF FOOD AROUND TEETH
• REGNART (1938): INORGANIC ACIDS CORRODED ENAMEL & DENTIN

16. • ERDL (1843): DESCRIBED FILAMENTOUS PARASITES – IN MEMBRANE FROM TEETH
• FICINUS (1847): OBSERVED FILAMENTOUS MICROBES IN CARIOUS LESIONS – DENTICOLAE
• CARIES – INFILTRATION > DECOMPOSITION OF ENAMEL AND DENTIN
• MECH. BY WHICH MICROBES CAUSE DECAY WAS NOT EXPLAINED

17. • W D MILLER (1890): ACIDS & MICROORGANISMS – DECAY
• PASTEUR: DISCOVERED MICROBES TRANSFORMS SUGARS TO LACTIC ACID BY FERMENTATION
• MILLER SUMMARIZED DENTAL DECAY IS A CHEMOPARASITIC PROCESS
CONSISITING OF TWO STAGES: DECALCIFICATION OF THE TISSUES AND
DISSOLUTION OF THE SOFTENED RESIDUE.

18. • INSTEAD OF CLASSICAL CHEMO-PARASITIC THEORY IT HAS BEEN PROPOSED THAT ORGANIC OR
PROTEIN ELEMENTS ARE INITIAL PATHWAY OF INVASION
• ACCORDING TO THEORY – ORGANIC COMPONENT IS MORE VULNERABLE & IS ATTACKED BY
HYDROLYTIC ENZYMES
• GOTTLIEB (1944): INITIAL ACTION DUE TO PROTEOLYTIC ENZYMES ATTACKING LAMELLAE, ROD
SHEATHS, TUFTS & WALLS OF DENTINAL TUBULES
- STAPHYLOCOCCUS AUREUS WAS INVOLVED BECAUSE OF YELLOW PIGMENTATION CONSIDERED
PATHOGNOMIC OF DENTAL CARIES

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20. • SCHATZ ET AL (1955): SIMULTANEOUS MICROBIAL DEGRADATION OF ORGANIC COMPONENTS
(PROTEOLYSIS) & DISSOLUTION OF MINERALS OF TOOTH (CHELATION)
• THEORY CONSIDERS CARIES TO BE A BACTERIAL DESTRUCTION OF TEETH WHERE INITIAL ATTACK IS
ESSENTIALLY ON ORGANIC COMPONENTS OF ENAMEL. BREAK DOWN PRODUCTS OF THIS ORGANIC
MATTER HAVE CHELATING PROPERTIES & THERE BY DISSOLVE MINERALS IN ENAMEL
• DECALCIFICATION IS MEDIATED BY VARIETY OF COMPLEXING AGENTS – ANIONS, AMINO ACIDS,
PEPTIDES, POLYPHOSPHATES, & CARBOHYDRATE DERIVATIVES

21. SULFATASE THEORY: PINCUS (1950) BACTERIAL SULFATASE HYDROLYZES MUCOITIN SULFATE OF
ENAMEL & CHONDROITIN SULFATE OF DENTIN PRODUCING SULFURIC ACID CAUSING
DECALCIFICATION
COMPLEXING & PHOSPHORYLATION THEORY: LURA (1967) HIGH BACTERIAL UTILIZATION OF
PHOSPHATES IN PLAQUE CAUSES A LOCAL DISTURBANCE IN PHOSPHATE EQUILIBRIUM RESULTING IN
LOSS OF INORGANIC PHOSPHATE FROM ENAMEL
- SOLUBLE CALCIUM COMPLEXING COMPOUNDS PRODUCED BY BACTERIA – FURTHER TOOTH
DISINTEGRATION

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28. CARIES IS MULTIFACTORIAL DISEASE:
A) ESSENTIAL FACTORS – BACTERIA, TOOTH STRUCTURE & DIETARY
CARBOHYDRATES
B) SECONDARY FACTORS – SALIVA, PLAQUE CONSTITUENTS, TIME, TRACE
ELEMENTS, ORAL HYGIENE ETC..

29. TOOTH STRUCTURE
• UNDERGOES CONTINUOUS CHANGES IN BOTH PHYSIOCHEMICAL AND MORPHOLOGICAL
PROPERTIES
• HEALTHY ENAMEL IS RESULT OF RELATIVELY STABLE OR FAVORABLE EQUILIBRIUM; & DISTURBANCE –
DISSOLUTION
• CARIES IS RESULT OF SERIES OF BACK & FORTH SHIFT IN CHEMICAL EQUILIBRIUM OF TOOTH
STRUCTURE WHICH IN SUMMATION DICTATES CONDITIONS MORE FAVORABLE TO INORGANIC
DISSOLUTION THAN RECRYSTALIZATION

30. • FUEL FOR CARIES PROCESS
• DEGRADABLE CARBOHYDRATES AS SOURCE OF BACTERIAL FERMENTATION TO ORGANIC ACIDS & AS
SUBSTRATE FOR ATP SYNTHESIS, FOR BACTERIAL SURVIVAL & PROLIFERATION
• DIETARY CARBOHYDRATES TO BE ACTIVE AS CARIOGENIC SUBSTRATES, IT MUST BE - IN READILY
USABLE MONOSACCHARIDE FORM
- EASILY BROKEN DOWN TO BACTERIAL METABOLITES

31. • DISACCHARIDE – GLUCOSE + FRUCTOSE
• MAJOR DIETARY FOOD STUFFS
• NEWBRUN CALLED SUCROSE AS “ ARCH CRIMINAL OF DENTAL CARIES “
• BECAUSE SUCROSE SERVES AS THE SUBSTRATE FOR EXTRACELLULAR
POLYSACHARIDE SYNTHESIS OF CERTAIN MICROBIAL ORGANISMS IMPLICATED IN
DENTAL CARIES.
- STUDIES HAVE SUPPORTED THIS INCRIMINATION (VIPEHOLM STUDY)
- SUCROSE CONDUCTIVE TO BOTH PLAQUE FORMATION & CARIES
• SO SUCROSE STANDS AS SINGLE MOST IMP. PREDISPOSING FACTOR IN CARIES PROCESS

32. • MICROORGANISMS ARE ESSENTIAL FACTOR FOR CARIES
• FERMENT DIETARY CARBOHYDRATES TO ACIDS > DEMINERALIZATION
AT BIRTH
- STREPTOCOCCUS MITIOR,STREPT SALIVARIUS,
NIESSERIA, STAPHYLOCOCCI, LACTOBACILLI.
- ANAEROBIC -- VEILLONELLA ALCALESCENS,
FUSOBACTERIA
- STRP MUTANS FOUND –NON-DESQUAMATING SURFACE.
- STRP MUTANS, STRP SANGIUS, A VISCOSUS– ONLY AFTER ERUPTION OF TEETH.

33. SALIVA
 HAS INHIBITORY EFFECT
 ACTS BY:
- MECHANICAL VIA CLEANSING
- CHEMICAL VIA SPECIFIC INTERACTIONS
 SALIVARY FLOW: INVERSELY PROPORTIONAL TO DEGREE OF CARIES ACTIVITY
 BICARBONATE BUFFERING CAPACITY
 SALIVARY GLYCOPROTEIN: LUBRICATION
 INORGANIC CONSTITUENTS: NA+, CL-, HCO3
-, K+, F-
– INHIBITION OF CARIES
 SECRETORY IMMUNOGLOBULIN (SIGA)
 PROTEINS: AMYLASE – CLEAVE MALTOSE
LYSOZYME – NON SPECIFIC ANTIBACTERIAL AGENT

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• LYSOSYME
• LACTOPEROXIDASE
• LACTOFERRIN
• UNSTIMULATED SALIVARY FLOWRATE- 0.3ML/MIN

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