CS4-4)DENTAL PLAQUE.Prof.Dr.Tamer Yılmaz.pdf

Dental plaque Prof. Dr. Tamer YILMAZ Near East University Dental Faculty Director of Basic Medical Science Departmet 1. What is Bacterial Plaque? 2. How does the bacterial plaque occur in the mouth? 3. What are the factors that lead to bacterial plaque formation? 4. What are the results of the for...

Dental plaque Prof. Dr. Tamer YILMAZ Near East University Dental Faculty Director of Basic Medical Science Departmet 1. What is Bacterial Plaque? 2. How does the bacterial plaque occur in the mouth? 3. What are the factors that lead to bacterial plaque formation? 4. What are the results of the formation of bacterial plaque in the mouth? Dental plaque Dental plaque • Dental caries and periodontal diseases are not caused by a single pathogenic microorganism. • Dental caries and periodontal diseases result from the accumulation of many different species of bacteria that form dental plaque. caries gingivitis caries Dental plaque • Dental plaque is a biofilm layer or mass of bacteria that grows on surfaces within the mouth. • Dental plaque a naturally acquired bacterial biofilm that develops on the teeth. Dental plaque • Dental plaque must be differentiated from other tooth deposits, like materia alba and calculus. • Materia Alba refers to soft accumulations of bacteria and tissue cells that lack the organized structure of dental plaque. • Calculus is hard deposits that form by mineralization of dental plaque and is generally covered by a layer of unmineralised plaque. Materia alba Calculus Dental plaque • • • • • It is observed In the pits and fissures of the teeth, Pit surfaces of molars and premolars In motionless areas In the mouth soft tissue. Dental plaque • Plaque can be defined as a complex microbial community, with greater than 1x1010 bacteria per milligram. • It has been estimated that as many as 400 distinct bacterial species may be found in plaque. Ten to the ten Dental plaque • In addition to the bacterial cells, plaque contains a small number of epithelial cells, leukocytes, and macrophages. • The cells are contained within an extracellular matrix, which is formed from bacterial products and saliva. • The extracellular matrix contains protein, polysaccharide, lipids and glycoproteins. Dental plaque • Dental plaque is a different microbial deposit embedded in polymers of bacteria and saliva. • With calcification of the plaque, tartar emerges. • Depending on the chemicals and cells in its structure, it can be white, gray or light yellow in color. • According to their location, it is called a sub or supra gingival plaque. Dental plaque • Plaque can also be classified by its relationship to the tooth surface, as either attached or unattached plaque. • The unattached subgingival plaque is more closely associated with the wall of the subgingival tissues than is the attached plaque. Dental plaque • Dental plaque is classified as two groups based on its relationship to the gingival margin. • Supragingival plaque is found at or above the gingival margin. • The supragingival plaque in direct contact with the gingival margin is referred to as marginal plaque. • Subgingival plaque is found below the gingival margin, between the tooth and the gingival sulcular tissue. Dental plaque • The different regions of plaque are significant to different processes associated with diseases of the teeth and periodontium. For example, • Marginal plaque gingivitis. • Supragingival plaque and tooth-associated subgingival plaque are critical in calculus formation and root caries. • Subgingival plaque soft tissue destruction different forms of periodontitis. Dental plaque • Most bacteria have been shown to live in complex communities called biofilms. • Biofilm is a collection of bacteria that are organized by first adhering to an extracellular. • Heart valves, catheters, lenses. Formation of Dental plaque • The formation of pellicle is the first step in plaque formation. • What is the pellicle? • An erupted tooth immediately becomes covered by a thin, microscopic coating of saliva materials. Formation of Dental plaque • The salivary components become adsorbed to the surface of the enamel within seconds at a newly cleaned tooth surface . Formation of Dental plaque • This coating is also referred to as a pellicle. • Negatively-charged glycoproteins from saliva adheres to the tooth surface with calcium groups of surface enamel. Formation of Dental plaque • The pellicle is defined as the acellular layer of adsorbed salivary proteins and other macromolecules on the dental enamel surface approximately 10 micrometers thick. • There are more water molecules in the subsurface layer, also called the hydration shell. The pellicle • The enamel pellicle also contains several components derived from the saliva, such as immunoglobulin A, cystatins, histatins, lysozyme, proline-rich and mucinous proteins. • It is a bacteria-free layer and serves two purpose: 1. Provide lubrication during mastication, 2. Protect the tooth from demineralization due to its selective-permeability, restricting transport of ions in and out of the dental hard tissues. Formation of Dental plaque • The second step of plaque formation is Biofilm formation. • Biofilms can be defined as communities of microorganisms attached to the pellicle surface. Dental plaque is an adherent deposit of bacteria and their products, which forms on all tooth surfaces. Dental Plaque is a (host-associated biofilm). Plaque formation • Second step is the initial colonization of the tooth surface. • The pellicle-coated tooth surface is colonized by Gram-positive bacteria such as Streptococcus sanguis, Streptococcus mutans, and Actinomyces viscosus. Plaque formation • These organisms are examples of the "primary colonizers" of dental plaque. • Bacterial surface molecules interact with components of the dental pellicle to enable the bacteria to attach or adhere to the pelliclecoated tooth surface. Plaque formation • After the initial colonization of the tooth surface, plaque increases by two distinct mechanisms: • 3. The multiplication of bacteria already attached to the tooth surface, and • 4. The subsequent attachment and multiplication of new bacterial species to cells of bacteria already present in the plaque mass. Formation of Dental plaque • 3. and 4. Stages names are Biofilm Maturation stages. Formation of Dental plaque • 3. and 4. Stages names are Biofilm Maturation stages. Formation of Dental plaque • 3. and 4. Stages names are Biofilm Maturation stages. Formation of Dental plaque • 3. and 4. Stages names are Biofilm Maturation stages. Formation of Dental plaque • 3. and 4. Stages names are Biofilm Maturation stages. Factors can affect plaque formation • 1. Oral hygiene. • 2. Orthodontic or prosthetic appliance as they may interfere with oral hygiene. • 3. Structure and position of the tooth. Roughness of enamel whether development or acquired encourages plaque accumulation. • 4. Diet greatly affects plaque formation. – Rough fibrous diet and the movement of mastication reduce plaque, while a sucrose rich diet encourages plaque deposition through sticky polymers. Dental plaque formation • Stages:1. Formation of pellicle In this stage, different bacteria reversibly or irreversibly attach to tooth surface enamel pellicle which acts as foundation for multilayered biofilm. Transport to surface Hence, in dental plaque development, two adhesion processes are required. A. The first stage involves the initial transport of the bacterium to the tooth surface. – Random contacts may occur – Brownian motion (average displacement of 40 µm/hour) – Sedimentation of microorganisms, – Liquid flow – Active bacterial movement (chemotactic activity). Initial adhesion B. There is an initial, reversible adhesion of the bacterium. It is initiated by the interaction between the bacterium and the surface, from a certain distance (50 nm), through long-range and short-range forces, including van der Waals attractive forces and electrostatic repulsive forces. Attachment • After initial adhesion, firm anchorage between bacterium and surface will be established by specific interactions (covalent, ionic, or hydrogen bonding). • The bonding between the bacteria and pellicle is mediated by specific extracellular components of organisms and complementary receptors on pellicle surface. a Microbial adhesion • With the synthesis of extracellular polymers, the adhesion is turned into irreversible. • These polymers make up an important part of the biofilm matrix. • These polymers are soluble and insoluble high molecular weight polysaccharides synthesized from fructose and glucose by extracellular glycosyl and fructosyl transferases. Dental plaque formation • 2. Colonization of bacteria In this stage, bacteria which attach in to the dental pellicle, start dividing forming microcolonies. This bacterial composition further grow into more mature complex flora • Primary colonizers: Gram-positive cocci. They provide new binding sites for adhesion by other oral bacteria. • Secondary colonizers: Gram-negative organisms (anaerobes) . They do not initially colonize the clean tooth surface but adhere to bacteria already in the plaque mass. Colonization of bacteria • In this stage, bacteria which attach in to the dental pellicle start dividing forming microcolonies. • This bacterial composition further grow into more mature complex flora. • Primary colonizers: Gram-positive cocci: They provide new binding sites for adhesion by other oral bacteria. • Secondary colonizers: Gram-negative organisms (anaerobes) . They do not initially colonize the clean tooth surface but adhere to bacteria already in the plaque mass. Maturation of biofilm • In two weeks, the plaque becomes more mature. • As the biofilm matures, spirochetes start growing into this area. • There is site-to-site differences in its composition, that is why caries progress in some sites but not others in the same mouth. Dental Plaque • • • • • • Plaque is not homogenous structure Consists of: - pellicle - bacteria - bacterial products - salivary constituents Composition of Biofilm • • • • • • Components of Biofilm Water Inorganic Components Organic Components Microorganisms Intermicrobial matrix http://cariology.wikifoundry.com/page/Dental +Biofilms 80% 20% Composition • • • • • • Cells: primarily bacteria, 1 gm (wet weight)= 1011 bacteria Non bacterial: Mycoplasma spp, yeasts, protozoa, viruses Host cells : epithelial cells, macrophages & leucocytes Matrix: Organic Inorganic Matrix • The material present between the bacteria in the dental plaque is called matrix or intermicrobial matrix. • accounts for approx 20-25% of plaque volume. • Three sources may contribute to the intermicrobial matrix: the plaque microorganisms the saliva gingival exudates • Degenerating or dead bacteria may also contribute to inter microbial matrix. Matrix • Organic and inorganic • SOLIDS approx 20 % and water • WATER 70 to 80 % of solid matter, which higher in sub gingival plaque than supra gingival. • INORGANIC: • Main Calcium and Phosphorus(mostly) magnesium, sodium fluoride(in small amount, higher than saliva) • CALCIUM AND PHOSPHATE more on lingual surface of anterior teeth. • ORGANIC: • Surrounds microorganisms contains carbohydrates, proteins and lipids Inter bacterial matrix: Composition of Biofilm • Organic constituents of the matrix include: • Glycoproteins from saliva are an important component of the pellicle and incorporated into the developing plaque biofilm. • Albumin (proteins), probably from crevicular fluid, has been identified as a component of the plaque matrix. • The lipid material consists of debris from the membranes of disrupted bacterial and host cells and possibly food debris. • Polysaccharides produced by bacteria, of which dextran is the predominant form, contribute to the organic portion of the matrix. Polysaccharides • Polysaccharides are basic molecules of bacterial plaque. • These molecules are synthesized by streptococci group bacteria. Polysaccharides • The host's dietary sucrose is converted by the bacterial enzymes glucosyltransferases and fructosyltransferases to the extracellular polysaccharides, glucans and fructans. • Glucans are the homopolysaccharides of glucose and fructans are the homopolysaccharides of fructose. Polysaccharides • • • • Glucans synthesize from sucrose and of two types: Dextran: serve as energy storage Mutan: acts primarily as a skeleton in the matrix. Glucans can be viscid substances that help anchor the bacteria to the pellicle, as well as stabilize the plaque mass. Polysaccharides • These polysaccharides include hydrogen bonding, are thought to contribute to the mediation of bacterial adhesion. • These molecules hydrophobic groups can interact with amino acid sidechain groups, such as serine, tyrosine, and threonine in the acquired pellicle. https://www.slideshare.net/drroshnimaurya/dental-plaque-52978826 Polysaccharides • Fructans (Levans) synthesized in plaque from dietary sucrose. • They provide a storage of energy which may be utilized by the microorganisms in time of low sugar supply. • Bacteria also use this molecules as a energy source. https://www.slideshare.net/drroshnimaurya/dental-plaque-52978826 Glycoproteins • Components of the dental pellicle include salivary glycoproteins and albumin, lysozyme, amylase, immunoglobulin A, proline-rich proteins and mucins. • Bacterial surface molecules interact with components of the dental pellicle to enable the bacteria to attach or adhere to the pellicle-coated tooth surface. • For example Streptococcus sanguis and Actinomyces viscosus bacteria have fimbria (hairlike protein)on their cell surface. • This proteins bound to the pellicle proteins. Bacterial plaque types by regions • 1.Fissur plaque: • Gram-positive cocci form plaques in fissures on the surfaces of the premolar and molars. • The microflora of fissures is less diverse than other areas on the tooth surfaces. • 2.Aproximal plaque: • Predominant bacteria are Gram-positive streptococci and Actinomyces species. Bacterial plaque types by regions • • • • 3. Gingival pocket plaque Gingival pocket contains a very different habitat. The ecology of the region is affected by saliva flow, nutrients and pocket fluid. Compared to the fissures and the approximal area, there are more bacterial species in this area. Anaerobic bacteria species such as Peptostreptococcus, Actinomyces, Propionibacterium, Bacteroides, Fusobacterium, Selenomonas and VeilloneIIa are largely and widely found. Gingival pocket plaque • Although there are chewing and saliva movements, it is observed that plaque cells adhere to the tooth surfaces very strongly in many areas. • Another important feature is the presence of bacteria in the environment that can break down various oligosaccharides and provide a source for plaque-forming bacteria. Gingival pocket plaque • Bacteria plaque can also be named according to its location in the gum pocket. Extracellular matrix in bacterial plaque • The bacteria that make up the bacterial plaque are found in a liquid environment, the basis of which is the pellicle, and a large part of it is made up of proteins. • This structure is also called extracellular matrix. Extracellular matrix in bacterial plaque • The structure of the plaque matrix is examined in two parts depending on the presence of residual nutrients: • 1.Plaque matrix in the absence of nutrients: • In the absence of nutrients, the bacterial plaque has a thin and highly porous structure. • It is largely composed of calcium and phosphate ions and proteins. • The sialic acid molecules attached to the protein structure are broken off by the bacteria in order to provide energy. Extracellular matrix in bacterial plaque • 2.Plaque matrix in the presence of nutrients • It has been determined that the bacterial plaque shows a very different development with the food residues remaining in the mouth. • It is observed that especially the presence of carbohydrates changes the composition of the plaque and the addition of polysaccharides to the structure. • A denser and thicker layer is formed compared to the previous one. Plaque fluid • It is the part of the bacterial plaque that contains soluble substances. • By means of this liquid, material exchange is provided between the external environment and the bacterial plaque, and the bacterial plaque and the tooth surface. • Plaque fluid can be easily removed from the plaque by centrifugation. • On average 500 mg bacterial plaque contains 150 nL plaque fluid. Plaque fluid • There are two types of plaque fluid that affect bacterial metabolic activity: • Resting plaque fluid Starved plaque fluid. • Resting plaque fluid is the plaque fluid collecting few hours after feeding. • Starved plaque fluid, on the other hand, is the plaque fluid obtained during the onset of hunger. Plaque fluid • Resting plaque fluid (56.3 - 102.1 mmol / l) contains more organic acid than fasting plaque fluid (31.9 - 61.5 mmol / l). • The pH values of both fluids are different from each other (resting plate fluid pH 5.69 - 6.54 fasting plate fluid pH 6.78 - 7.08). • The resting plate fluid pH is lower. Because bacteria are used as an energy source of carbohydrate sources in the environment and organic acids are released when they break down of these carbohydrates. • It is seen that the pH of the plaque fluid increases with hunger. Stephan curve • With the Stephan curve the change in the bacterial plaque against any factor is determined. • The factors are usually one of several nutrients. • The relationship between sugar arrival time and plaque pH can be demonstrated with the Stephan curve. Stephan curve • The main factor that determines the shape of the Stephan curve and causes the pH increases is the flow rate of the saliva. • Tükürüğün iki önemli etkisi vardır. • 1. Dilutes and reduces the effects of acids liberated in the plate. • 2. Saliva bicarbonate ions diffusing into the plate neutralize the acids formed there and increase the pH. Salivary carbonic anhdrase • Saliva carbonic anhydrase is synthesized and secreted from the parotid and submandibular glands. It is the only example of carbonic anhydrase secreted in mammals. • Acid neutralization is accelerated by increasing the synthesis rate with salivary carbonic anhydrase. carbonic anhydrase rase. Quantity • The figure shows the effect of the amount of saliva on the pH of saliva. • These critical pH values can vary from person to person. pH • Critical pH values measured on the Stephan curve and considered to cause caries attacks are shown in bold in the figure. Minutes After rinsing with sucrose Cariogenic attacks • The frequency of cariogenic attacks caused by bacterial plaque has also been investigated by experiments. • Bacterial plaque-induced caries attacks can occur in 6 different periods in a 24-hour period. • These values are the normal minimal values observed in healthy people. • The breaks of pride and the frequency of feeding cause these attacks to increase. pH • The main causes of pH drop in bacterial plaque: – Plaque bacteria composition – Presence of fermentable carbohydrates – The diffusion rate of metabolites and substrates that can enter and exit the plate. • The pH starts to rise in two ways: – Separation of synthesized acids from plaque – Diffusion of bicarbonate ions in saliva to plaque • In addition, low pH has the effect of inhibiting the metabolism of bacteria. pH • Increasing the pH of the plaque is also very important. • In resting conditions, almost every individual has a certain pH value of the plaque and it is stable. • It has been observed that there are significant differences between individuals in these values. • Plaque pH in carious-inactive individuals is between 6.5 and 7.0, and it can drop to 5.0 after sugar applications. pH • It was determined that the pH was lower in carious-active individuals and remained around 5.0 for a longer time after sugar applications. • The metabolic residues left by the bacteria active at this pH are effective in the formation of caries Chemical structure of dental plaque • There is approximately 80% water in the bacterial plaque. • 20% of the plate is solid materials. • Proteins are mostly found in solids and constitute 40-50% of the dry weight of the plate. • 13-18% carbohydrates • There are 10-14% oils. Inorganik structure of dental plaque • The inorganic composition of the bacterial plaque varies greatly depending on external factors other than the basic two elements. • Plaque contains more calcium and phosphate than saliva. • Sodium, potassium and fluorine, in small amounts, are the main components of the inorganic composition. • Ca++ and P04-3 levels in bacterial plaque play an important role in the pathogenesis of dental caries and calculus formation. Fluorine • Bacteria plaque also contains fluorine from external sources. • Fluorine concentration in plaque (14-20 ppm) is higher than in saliva (0.01-0.05 ppm). • Most fluorides are bound either to inorganic substances or to bacteria. • Fluorine is a cariostatic element. • For this reason, the amount of fluoride in the plaque is highly effective in preventing the cariogenic activities of bacteria in the environment and preserving the stable structure of enamel. Fluorine • During fermentation, more free fluoride ions are released due to the decrease in the pH of the plate. • This event prevents the pH of the plaque from falling further and stimulates the formation of fluoroapatite, which prevents caries. • The fluorine source of the bacterial plaque is drinking water, food and saliva. Proteins of bacterial plaque • Proteins inside the plaque originate from bacteria, saliva or gum fluid. • Various salivary proteins such as amylase, lysozyme, Ig A, Ig G, IgM and albumin are found in the plaque. • The qualitative and quantitative values of these proteins vary from individual to individual. • These molecules can also be found in solid or fragmented form. Proteins of bacterial plaque • Ayrıca statherin, asidik prolince-zengin proteinler, amilaz, histatinler, sistatinler, müsin, lisozim, albumin, karbonik anhidraz gibi pellikl yapısında bulunan proteinlere de doğal olarak plak yapısında rastlanmıştır. • Antikorlar immunolojik reaksiyonlarda etkilidirler. • Ayrıca proteinler plak içinde tampon vazifesi de görürler. Carbohydrates of bacterial plaque • The main monosaccharide found in hydrolyzed plaques is glucose. • Also, arabinose ribose, galactose, and fucose can be found. • Most carbohydrates are in the form of either glucans and mutants or heteropolysaccharides. • They exist as extracellular polymers. • The synthesis of these polysaccharides is done by certain plaque microorganisms. Carbohydrates of bacterial plaque • Glucans are either dextrans or mutants. • Mutants help form the skeleton of plaque, like the cellulose in plants. • Glucans and levanes serve as a fermentable carbohydrate store for plaque metabolism. Carbohydrates of bacterial plaque • In addition, there are carbohydrates in the form of intracellular "glycogen" in plaque bacteria. • When exogenous fermentable carbohydrates are not available, organisms can continue to make acid with their own spare carbohydrates inside the cell. Carbohydrates of bacterial plaque • The bacterial plaque extracellular polysaccharide composition consists of glucose and fructose polymers synthesized by more than 12 streptococcal species. Carbohydrates of bacterial plaque • These polymers are synthesized extracellularly by bacteria-synthesized fructose transferase (FTF) or glucose iltransferase (GTF) enzymes. • In addition to these enzymes, bacteria are also synthesized by bacteria, such as dextranase, that can break down these polymers when necessary. Fructans • This term is used as the general name for fructose polymers. • Two types of fructose polymers are synthesized from sucrose-derived fructose in the mouth. • Although there is not enough evidence yet, it can be said that both types were synthesized to be used as energy storage. β2,1-Fructan • It is formed as a result of binding of fructose molecules with β2,1 bonds. • It is found in the structure of some vegetables and is also known as inulin. β2,1-Fructan • They are synthesized instead of starch to be stored as an energy source in the seeds of plants. • β-2,1 fructan is known to be synthesized only by S. mutans. • However, it was determined that some S. salivarius species also synthesizes. • They are used as an energy store in the absence of nutrients by both synthesizing bacteria and other mini-organisms in their plaque structure. β2,1-Fructan • It has been determined that the polymers synthesized by some S. mutans species consist of β-2,1 and β-2,6 bonded polymers. • It is accepted that there are β-2,6 cross-links in the chain in places. Levan (β-2,6 Fructan) • Levan is synthesized not only by S. mutans but also by S. sanguis, S. salivarius and Actinomyces naeslundii. Glucans • It is generally thought that there are two types of glucans. • Water soluble and insoluble glucans. • Although each type has a wide variety of subtypes, α-1,3-linked or α-1,6-linked glucose molecules form the core structure in all polymers. • In general, α-1,3 bonds make the structure water insoluble. • α-1,6 bonds make the structure water soluble. Water insoluble polymers (mutan) • One of the first polymers identified is glucose polymer formed by α-1,3 glycosidic bonds obtained from S. Sobrinus. • Previously, Strep sobrinus species were considered to be a subspecies of Strep mutans. • For this reason, these polymers are called mutants. Water insoluble polymers (mutan) • As a result of the analysis of polymers synthesized by other species, it was understood that 85-90% of glucose in their structures is bound by α-1,3 bond and the rest are branched structures with α-1,6 bonds. Water insoluble polymers(dextran) • All α-1.6 linked glucose polymers are synthesized only by Streptococcus salivarius. • Since these polymers turn polarized light to the right, the molecules are called dextran. Poliymers • Polymers are formed by the binding of glucose or fructose released by the breakdown of sucrose in the environment. • The released monosaccharides trigger the reaction. • This reaction can be written for all polymers: Extracellular polysaccharides and caries etiology • Many things cause the formation of caries, but bacterial plaque has a much more important place than others. • S. mutans or other species maintain their cariogenic effects inside the plate. • Before the appearance of caries, there are extracellular polysaccharides and sugar in the plaque residues adhering to the tooth surface. Yüksek karbonhidrat diyeti • Due to the acid by-products released during the fermentation of carbohydrates, the resting plate pH will begin to drop and will drop to around 6.3 and 6.8. • This low and more acid pH causes the growth and proliferation of acidogenic microorganisms such as streptococci and lactobacillus. • However, a significant decrease is observed in the reproduction and development of gram negative anaerobic rods. High sucrose • If the amount of sucrose used is increased, it is seen that the plaque matrix contains large amounts of extracellular polysaccharides glucan and fructan. • If carbohydrates commonly used in the diet are abundant, it is seen that organisms such as Streptococcus mutans and lactobacillus increase too much. Plaque and dental dieases • The bacteria in plaque cause tooth decay and gum disease . • Periodontal or gum disease is a pathological inflammatory condition of the gum and bone support (periodontal tissues) surrounding the teeth. • Microorganisms in the dental plaque ferment carbohydrate foodstuffs, especially the disaccharide sucrose, to produce acids that cause demineralization of inorganic substances. Plaque and dental dieases • Bacteria in plaque can use all fermentable carbohydrates to form acid, thus, almost all sorts of food lead to increase of acidity in plaque. • Both enamel on the surface of teeth and dentine inside teeth are composed of minerals. • This acids cause demineralization of inorganic substances. • Loss of minerals due to the increase of acidity is known as demineralization • Furnish various proteolytic enzymes to cause disintegration of the organic substances of the teeth and soft tissues. Plaque and dental dieases • Results of the effects are gingivitis and periodontitis. • What are the symptoms of plaque-associated gum disease?: • Mild gingivitis: • It does not cause any symptoms and so you may not realise that you have it. • The gums look slightly swollen. şiş Plaque and dental dieases • Results of the effects are gingivitis and periodontitis. • What are the symptoms of plaque-associated gum disease: • Mild gingivitis: • Moderate gingivitis: • cause more marked swelling and reddening of the gums. • The gums often bleed a little when you clean your teeth. Plaque and dental dieases • Results of the effects are gingivitis and periodontitis. • What are the symptoms of plaque-associated gum disease: • Mild gingivitis: • Moderate gingivitis: • Periodontitis:• often does not cause any symptoms until an affected tooth becomes loose. In some cases, symptoms develop and may include: • 1)halitosis (bad breath). • 2)some pus formation in small pockets between teeth and gums. • 3)Pain and difficulty in eating. Plaque and dental dieases • The acids that cause tooth demineralization tend to be produced by specific types of bacteria, specifically streptococci mutans and lactobacilli. • The primary home of these bacteria is within dental plaque. • The bacteria that cause cavities are living organisms. • And just like all living things they consume food and in return create waste products. Plaque and dental dieases • Bacteria associated with periodontal diseases generally have proteolytic activity. • These bacteria directly damage the tissue or the tissue's defense mechanism. • They also synthesize cytotoxic metabolites (acids, ammonia and sulfur-containing compounds) and release them into a healthy tissue environment. • A single bacterium cannot produce all of these. • Therefore, periodontal diseases can be considered as a polymicrobial infection.