Isolation Of Microorganisms Associated With Dental Caries In Patients
Isolation Of Microorganisms Associated With Dental Caries In Patients. Dental caries is commonly known as tooth decay. In the minds of the lay person, and surprisingly even within dentistry, dental caries is often thought of as holes in the teeth rather than an entire disease process.
TABLE OF CONTENTS ON ISOLATION OF MICROORGANISMS ASSOCIATED WITH DENTAL CARIES IN PATIENTS
Title Page i
Table of Contents v
List of Tables vii
1.0 Introduction 1
1.1 Statement of Problem 3
1.2 Aim of the Study 3
1.3 Objectives of the Study 3
2.0 Literature Review 5
2.1 Composition of the Human Teeth 5
2.1.1 Enamel 5
2.1.2 Dentin 6
2.1.4 Pulp 7
2.2 Dental Plaque and Dental Pellicle 8
2.2.1 Dental Plaque 8
2.2.2 Dental Pellicle 8
2.2.3 Dental Plaque Formation 8
2.2.4 Dental Pellicle Formation 9
2.3 Process of Dental Caries Formation 10
2.3.1 Remineralization/Tooth Repair 12
2.3.2 Calcium Deficient Area 12
2.4 The Role of Saliva in Dental Caries 13
2.4.1 Critical pH 14
2.5 The Role of Fermentable Carbohydrates in Caries Formation 14
2.5.1 Cariogenic Potential 15
2.5.2 Physical Traits 16
2.6 The Caries Continuum, the Caries Balance and Clinical Relevance 17
2.7 Use of Probiotics in Controlling Dental Caries 19
2.8 Oral Hygiene and Dental Caries 19
2.9 Gender Differences in Caries 20
3.0 Materials and Methods 21
3.1 Materials 21
3.1.1 Glass Wares and Equipments 21
3.1.2 Reagents and Chemicals 21
3.2 Methods 21
3.2.1 Sterilization of Glass Wares 21
3.2.2 Preparation of Media 22
3.2.3 Collection of Samples 22
3.2.5 Isolation of Bacteria 22
3.2.6 Characterization 23
22.214.171.124 Gram Staining 23
126.96.36.199 Biochemical Tests 23
3.6 Identification of Microbial Isolates 25
4.0 Results 26
5.0 Discussion and Conclusion 31
5.1 Discussion 31
5.2 Conclusion 32
5.3 Recommendation 32
Dental caries is commonly known as tooth decay. In theminds of the lay person, and surprisingly even withindentistry, dental caries is often thought of as holes inthe teeth rather than an entire disease process. However,it has been known for over 100 years that dentaldecay is caused by bacteria fermenting foods, producingacids and dissolving tooth mineral. In recent decadesthe process has been much better defined from severalaspects including microbiology, saliva, tooth mineralcomposition, tooth ultrastructure, diffusion processes,kinetics of demineralization, the reversal of demineralizationthat is known as remineralization, and factorsthat contribute to the reversal of the process (Featherstone, 2000). Now,we have a rather deep understanding of what goes on inthe mouth, but this knowledge is far from beingeffectively utilized in dental practice.The so-called cariogenic bacteria are essential to thedisease process. At least two major groups of bacteria,namely the mutans streptococci and the lactobacillispecies, are able to produce organic acids duringmetabolism of fermentable carbohydrates by thesebacteria (Marsh, 1994).
The acids produced include lactic,acetic, formic and propionic, all of which have beenshown to readily dissolve the mineral of the enameland dentine (Featherstone and Mellberg, 1981; Featherstone and Rodgers, 1981). Bacteria which produce acid as aby-product of their metabolism are known as acidogenic,and some, such as the groups named above, areaciduric and can live in an acid environment.
Dental caries is one of the most common chronic infectious diseases in the world (Anusavice, 2002). Bacterial plaque accumulated on dental surfaces and composed of native oral flora is the primary etiologic agent of dental caries. Cariogenic bacteria interact by various recognized ways including co-aggregation (Kolenbranderet al., 2000), metabolic exchange, cell- cell communication (Li et al., 2002), and exchange of genetic material (Roberts et al., 2001). These mechanisms benefit bacterial survival and can make dental biofilms difficult therapeutic targets in dental diseases.
Dental caries cause destruction of enamel, dentin or cementum of teeth due to bacterial activities. The burden of dental caries is still a major health problem in most industrialized countries as it affect 60% – 90% of school-aged children and the vast majority of adult. This is largely due to the increasing consumption of sugar and inadequate exposure to fluorides (Petersen et al., 2005).
When organic acids are produced by the bacteriain dental plaque on the tooth surface they readilydiffuse in all directions and of course diffuse throughthe pores of enamel or dentine and into the underlyingtissue. As the acid diffuses into the tooth it finds acidsoluble mineral and begins to dissolve it (Yooet al., 2007; Hoover and Newbrun, 1977). If thisprocess progresses long enough, the end result is acavity. This process in the mouth usually takes manymonths or years to progress to cavitation, the end-pointof the disease process known as dental caries.Dental caries is a transmissible bacterial diseasecaused primarily by the bacteria listed above feedingon the carbohydrates taken into the mouths ofhumans (Bowen, 2002).
The so-called cavity or hole in the toothis the end-point. Bacteria are transferred to babies frommothers or caregivers very early in the child’s life, withcolonization of soft tissues possible even before theteeth erupt (Sutherland, 2001; Li et al., 2001; Salam et al., 2001).
As the teeth erupt the cariogenicbacteria colonize them, establish as dental plaque, andthe cycle of destruction begins.
1.1 Statement of Problem
The increasing rate at which patients with dental cases visit Federal Teaching Hospital, Abakaliki is alarming. Dental caries is the most prevalent oral disease among the dental cases. The disease is believed to be caused by consumption of carbohydrates leaving certain amount of sugar in the mouth,hence the need to isolate the microfloras involved in the breakdown of the sugar and to determine the association of such microfloras with dental caries.
1.2 Aim of the Study
The aim of this study is to isolate the microorganisms associated with dental caries in patients visiting Federal Teaching Hospital, Abakaliki.
1.3 Objectives of the Study
a. To isolate and identify the microorganisms that are associated with dental caries in patients visiting Federal Teaching Hospital, Abakaliki.
b. To assess the prevalence of dental caries among patients with dental cases visiting Federal Teaching Hospital, Abakaliki.
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2.0 LITERATURE REVIEW
Dental caries is an infectious disease which damages the structures of teeth. The disease can lead to pain, tooth loss, and infection. Dental caries has a long history, with evidence showing the disease was present in the Bronze, Iron, and Middle ages but also prior to the neolithicperiod.The largest increases in the prevalence of caries have been associated with diet changes (Suddick and Harris, 1990).
Today, caries remains one of the most common diseases throughout the world. In the United States, dental caries is the most common chronic childhood disease, being at least five times more common than asthma. Countries that have experienced an overall decrease in cases of tooth decay continue to have a disparity in the distribution of the disease (Touger-Decker and van Loveren, 2003). Among children in the United States and Europe, 60–80% of cases of dental caries occur in 20% of the population (Touger-Decker and van Loveren, 2003).
Tooth decay is caused by certain types of acid-producing bacteria which cause the most damage in the presence of fermentablecarbohydrates such as sucrose, fructose, and glucose(Hardie, 1982; Moore and Moore, 1983). The resulting acidic levels in the mouth affect teeth because a tooth’s special mineral content causes it to be sensitive to low pH.
Depending on the extent of tooth destruction, various treatments can be used to restore teeth to proper form, function, and aesthetics, but there is no known method to regenerate large amounts of tooth structure. Instead, dental health organizations advocate preventative and prophylactic measures, such as regular oral hygiene and dietary modifications, to avoid dental caries (Moore and Moore, 1983).
2.1 Composition of the Human Teeth
Enamel is the hardest and most highly mineralized substance of the body. It is one of the four major tissues which make up the tooth, along with dentin, cementum, and dental pulp (Ross, 2002). It is normally visible and must be supported by underlying dentin. 96% of enamel consists of mineral, with water and organic material comprising the rest (ten Cate, 1998). The normal color of enamel varies from light yellow to grayish white.
At the edges of teeth where there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Since enamel is semi-translucent, the color of dentin and any restorative dental material underneath the enamel strongly affects the appearance of a tooth. Enamel varies in thickness over the surface of the tooth and is often thickest at the cusp, up to 2.5mm, and thinnest at its border, which is seen clinically as the CEJ (ten Cate, 1998). The wear rate of enamel, called attrition, is 8 micrometers a year from normal factors.
Enamel’s primary mineral is hydroxylapatite, which is a crystallinecalcium phosphate (Johnson, 1998). The large amount of minerals in enamel accounts not only for its strength but also for its brittleness. Dentin, which is less mineralized and less brittle, compensates for enamel and is necessary as a support (Johnson, 1998). Unlike dentin and bone, enamel does not contain collagen. Instead, it has two unique classes of proteins called amelogenins and enamelins. While the role of these proteins is not fully understood, it is believed that they aid in the development of enamel by serving as framework support among other functions (ten Cate, 1998).
Dentin is the substance between enamel or cementum and the pulp chamber. It is secreted by the odontoblasts of the dental pulp (Ross, 2002).
The formation of dentin is known as dentinogenesis. The porous, yellow-hued material is made up of 70% inorganic materials, 20% organic materials, and 10% water by weight (ten Cate, 1998). Because it is softer than enamel, it decays more rapidly and is subject to severe cavities if not properly treated, but dentin still acts as a protective layer and supports the crown of the tooth.
Dentin is a mineralized connective tissue with an organic matrix of collagenous proteins. Dentin has microscopic channels, called dentinal tubules, which radiate outward through the dentin from the pulp cavity to the exterior cementum or enamel border (Ross, 2002). The diameter of these tubules range from 2.5 μm near the pulp, to 1.2 μm in the midportion, and 900 nm near the dentino-enamel junction (ten Cate, 1998).
Although they may have tiny side-branches, the tubules do not intersect with each other. Their length is dictated by the radius of the tooth. The three dimensional configuration of the dentinal tubules is genetically determined.
Cementum is a specialized bone like substance covering the root of a tooth (Ross, 2002). It is approximately 45% inorganic material (mainly hydroxyapatite), 33% organic material (mainly collagen) and 22% water. Cementum is excreted by cementoblasts within the root of the tooth and is thickest at the root apex. Its coloration is yellowish and it is softer than either dentin or enamel.
The principal role of cementum is to serve as a medium by which the periodontal ligaments can attach to the tooth for stability. At the cemento-enamel junction, the cementum is acellular due to its lack of cellular components, and this acellular type covers at least ⅔ of the root (ten Cate, 1998). The more permeable form of cementum, cellular cementum, covers about ⅓ of the root apex.
The dental pulp is the central part of the tooth filled with soft connective tissue (ten Cate, 1998). This tissue contains blood vessels and nerves that enter the tooth from a hole at the apex of the root (Ross, 2002). Along the border between the dentin and the pulp are odontoblasts, which initiate the formation of dentin (ten Cate, 1998). Other cells in the pulp include fibroblasts, preodontoblasts, macrophages and T lymphocytes(Walton, 2002). The pulp is commonly called “the nerve” of the tooth.
2.2 Dental Plaque and Dental Pellicle
2.2.1 Dental Plaque
Dental plaque is defined as the soft deposits that form the biofilm adhering to the tooth surface. Plaque is composed of organic, inorganic materials derived from saliva, gingival crevicular fluid & bacterial products. The organic constituents of plaque include polysaccharides, proteins, glycoproteins & lipid material. The inorganic constituents of plaque include primarily of calcium & phosphorus &traces of sodium, potassium (Kolenbranderet al., 2010).
2.2.2 Dental Pellicle
Pellicle is a glycoprotein, derived from components of saliva and crevicular fluid as well as from bacteria and host tissue cell products and debris. Pellicle is formed on all surfaces of the oral cavity, including all tissue surfaces as well as surfaces of teeth and fixed and removable restorations if any. Pellicle functions as a protective barrier but pellicle provides a substrate on which bacteria progressively accumulate to form Dental Plaque. Pellicle provides a medium or base on which bacteria in the oral cavity attach. Pellicle gets easily stained & may display many colors ranging from white to dark brown due which the teeth appear discolored (Hannig and Hannig, 2009).
2.2.3 Dental Plaque Formation
The initial step in the process leading to dental plaque is the formation of the dental pellicle, an acellular, essentially bacteria-free protein layer (Dawes et al. 1963).