CARIOLOGY Dr. Shahzadi Tayyaba Hashmi

To describe caries process To describe sites that are vulnerable to caries List bacterial strains most responsible for caries Explain importance of carbohydrates exposure to caries To describe caries process To describe sites that are vulnerable to caries List bacterial strains most responsible for caries Explain importance of carbohydrates exposure to caries LEARNING OBJECTIVES

The study of dental caries and cariogenesis is known as cariology DENTAL CARIES also known as tooth decay or a cavity It is defined as an infection which is bacterial in origin and causes demineralization and destruction of hard tissues of teeth (enamel, dentine and cementum) CARIOGENESIS The Production of dental caries is termed as cariogenesis The study of dental caries and cariogenesis is known as cariology DENTAL CARIES also known as tooth decay or a cavity It is defined as an infection which is bacterial in origin and causes demineralization and destruction of hard tissues of teeth (enamel, dentine and cementum) CARIOGENESIS The Production of dental caries is termed as cariogenesis INTRODUCTION

Dental caries is a multifactorial disease of teeth. The major factors in the etiology of dental caries are as follows:  Diet  Bacteria  Susceptible tooth surface  Time Dental caries is a multifactorial disease of teeth. The major factors in the etiology of dental caries are as follows:  Diet  Bacteria  Susceptible tooth surface  Time ETIOLOGY OF DENTAL CARIES

Cariogenic (acidogenic) bacteria Bacterial plaque Stagnation areas Fermentable bacterial substrate(sugar) Susceptible tooth surfaces time Cariogenic (acidogenic) bacteria Bacterial plaque Stagnation areas Fermentable bacterial substrate(sugar) Susceptible tooth surfaces time Essential requirements for development of dental caries

Streptococci are essential for development of dental caries Acidogenic Able to produce a pH low enough (<5) to decalcify tooth substance Able to survive and produce acid at low levels of pH Able to produce polysaccharides (glucans) It adheres to pellicle and contributes to plaque formation Streptococci are essential for development of dental caries Acidogenic Able to produce a pH low enough (<5) to decalcify tooth substance Able to survive and produce acid at low levels of pH Able to produce polysaccharides (glucans) It adheres to pellicle and contributes to plaque formation 1) Essential properties of cariogenic bacteria

Dental caries is a bacterial disease The organisms mainly responsible are specific strains of Streptococcus mutans The presence of S.mutans in the human mouth is associated with caries activity Other bacteria including lactobacilli and other strains of streptococci are weakly cariogenic Dental caries is a bacterial disease The organisms mainly responsible are specific strains of Streptococcus mutans The presence of S.mutans in the human mouth is associated with caries activity Other bacteria including lactobacilli and other strains of streptococci are weakly cariogenic Microbiological aspects of dental caries

Plaque is a tenaciously adherent deposit that forms on tooth surfaces Consist of an organic matrix containing a dense concentration of bacteria In microbiological terms, plaque is a biofilm Biofilm consist of hydrated viscous phase formed from bacteria and their extracellular polysaccharide matrices Biofilm may be resistant to antimicrobials Plaque is a tenaciously adherent deposit that forms on tooth surfaces Consist of an organic matrix containing a dense concentration of bacteria In microbiological terms, plaque is a biofilm Biofilm consist of hydrated viscous phase formed from bacteria and their extracellular polysaccharide matrices Biofilm may be resistant to antimicrobials 2) Bacterial plaque

Clinically, bacterial plaque is a tenaciously adherent deposit on the teeth It can only be readily removed by tooth brushing However no tooth brushing removes plaque from inaccessible areas or pits (stagnation areas) Plaque becomes visible, particularly on the labial surfaces of incisors, when tooth brushing is stopped for hours Appears as a translucent film Clinically, bacterial plaque is a tenaciously adherent deposit on the teeth It can only be readily removed by tooth brushing However no tooth brushing removes plaque from inaccessible areas or pits (stagnation areas) Plaque becomes visible, particularly on the labial surfaces of incisors, when tooth brushing is stopped for hours Appears as a translucent film Clinical appearance of bacterial plaque

DENTAL PLAQUE Appears as translucent film

Deposition of cell-free pellicle of salivary glycoprotein Further deposition of pellicle enhanced by bacterial action Colonisation of cell free layer by bacteria, particularly by S.sanguis and S.mutans within 24 hours Progressive build-up of plaque substance by bacterial polysaccharides Deposition of cell-free pellicle of salivary glycoprotein Further deposition of pellicle enhanced by bacterial action Colonisation of cell free layer by bacteria, particularly by S.sanguis and S.mutans within 24 hours Progressive build-up of plaque substance by bacterial polysaccharides Stages of plaque formation

Sucrose forms up to a third of the carbohydrate content of many person’s diet It promotes colonisation of teeth by streptococcus mutans Its small molecular size allows it to diffuse rapidly into plaque Its dissacharide bond contains enough energy to react with bacterial enzymes to form extracellular dextran matrix Sucrose forms up to a third of the carbohydrate content of many person’s diet It promotes colonisation of teeth by streptococcus mutans Its small molecular size allows it to diffuse rapidly into plaque Its dissacharide bond contains enough energy to react with bacterial enzymes to form extracellular dextran matrix 3)Factors determining the cariogenecity of sucrose