牙体牙髓病学概论.ppt

Cariology and Endodontics,A discipline to study the etiology, pathogenic mechanism, pathology, pathology-physiology,clinical expression,treatment and favorable turn etc. of the disease on dental hard tissue and pulp tissue.,Concept,The content of the textbook,Cariology Non-cariogenic disease of dental hard tissue Endodontics Operative dentistry,History,In 50s years,Oral medicine Cariology Operative dentistry Endodontics Non-cariogenic disease of dental hard tissue Disease of Oral mucosa Preventive dentistry Periodontology Paediatrics for dentistry,Stomatology in ancient times,Before Christ (B.C.) There were some record about caries,Image liking character (script) worm + tooth,The chinese were known to have treated dental ills with knife, cautery, and acupuncture, a technique whereby they punctured different areas of the body with a needle.,In Dynasty Han (A.D.215282),There are some record about periodontology,Anno Domini,Pulpitis In Han, Mr. Zhang Zhong Jing Jin Gui Yao luewas a very famous writings in which there was a record about arsenic Arsenic is a toxicant medicine which has been generally used for killing pulp,In Dynasty Tang (A.D.710 era) the people use silver paste to fill tooth decay,In Tang, tooth brush with willow twig a toothbrush with hair planted was invented in A.D.911 century from a tomb of an emperors son-in-law of Liao from Chi Fong city,3 events above described,reflected ancient civilization of our country,Dentistry development in West country,The first known dentist was an Egyptian named Hesi-re (3000 B. C.). He was chief toothist to the pharaohs, he was also a physician, indicating an association between medicine and dentistry.,The Greeks,Hippocrates (500 B. C.) appreciated the importance of teeth. He accurately described the technique for reducing a fracture of the jaw and also replacing a dislocated mandible. He was familiar with extraction forceps for this is mentioned in one of his writings.,Aristotle (384 B.C.) also stated figs and soft sweets produce decay.,Galen (200A. D. Romans),was first to recognize that toothache could be: Pulpitis or pericementitis He also classified teeth into centrals, cuspids and molars.,B. Leonardo da Vinci (end of 15th Century) - he described the anatomy of the jaws, teeth and maxillary sinus. These drawings are the first to accurately describe the maxillary sinus. However, credit has been given to Dr. Nathaniel Highmore of England (1650).,D. Leeuwenhoek (17th Century) - invented the microscope. He described the dental tubuli and was the first to see organisms of the mouth,Anton van leeuwenhoek,K. John Greenwood (1789) - dentures for George Washington were made by him.,a red laser scans,George Washingtons false teeth not wooden Laser scans find gold, ivory, lead, human and animal teeth,L. Pierre Fauchard (18th Century - 1728) - Father of Scientific Dentistry. Wrote a great text “Surgeon Dentist“. He also wrote a complete work on Odontology in two volumes, 843 pages. He recognized the intimate relationship between oral conditions and general health. He advocated the use of lead to fill cavities. He removed all decay and if the pulp was exposed, he used the cautery.,Musee dArt Dentaire Pierre Fauchard at the Academie Nationale de Chirurgie Dentaire 22 Rue Emile Menier, 75116, Paris France,He prescribed oil of cloves and cinnamon for pulpitis. He described partial dentures and full dentures in his text. He constructed dentures with springs and used human teeth. Gold dowels were used in root canals filled with lead. He was also known as Father of Orthodontics. Fauchard died in 1768 at the age of 83.,1763 A.D,John Baker, M.D. Surgeon Dentist. The earliest qualified dentist to practice in Boston and in America.,1836 A.D.,Arsenic introduced for the killing of pulps, by Spooner.,1840 A.D.,The American Society of Dental Surgeons, first national dental organization. The Baltimore College of Dental Surgery, the first school in the world for the training of dentists was founded by Harris and Harden.,Founded by Harris and Harden,1859 A.D.,Organization of American Dental Association on a representative basis.,1890 W.D. Miller propose a chemical-bacteria Paraorganism theory to explain the mechanism of caries,1891 A.D.,Extension for prevention and scientific cavity preparation promulgated by G.V. Black. 1892 A.D. The establishment of a three-year course in dental colleges.,1906 A.D.,Einhorn recommends novacaine and adrenalin combination for local anesthesia.,1915 A.D.,McKay and Black publish results of investigation of fluoride in drinking water.,1956 A.D.,Air-rotor drill, 250,000 RPM Dr. Robert Borden.,Stomatology in China before 1949,West China University (1910) Shanghai Second University(1920) 4th Military Medical University(1935) Beijing University(1943),Shanghai Second University,West China University 1918(School 1910),The first dental school in China was founded in West China Medical University in 1917.,A. W. Lindsay was teaching,After 1949 Hubei Medical College 1960,In recent 20 years, the science and techniques got great progress There are 12 faculties or dental schools in each province,Caries research Caries Vaccine Etiology & prevention Pulp disease Modern root canal traitment Pulp biology Stem cell final target,Achievements,Craniofacial-oral-dental research in the century,21st,The leadership team of NIDR initiated a strategic planning process in 2019 to identify,Where we are (strengths, weaknesses, opportunities and threats) Where we want to go (e.g., mission and vision) How we plan to get there (strategic plan),Several scientific areas will be concerned in century,21st,From molecular biology to clinical investigations; etiology, pathogenesis, epidemiology, prevention, diagnosis and treatment of inherited craniofacial-oral-dental diseases and disorders. e.g., ectodermic, dysplasia, cleft lip and palate, amelogenesis imperfect, dentin genesis imperfect, osteogenesis imperfect, and other inherited diseases.,Inherited disease and disorders,Hereditary hypoplasia,Hereditary aplasia of the enamel,dental caries Periodontitis Oral candidiasis Herpes Hepatitis,HIV/AIDS,Infections diseases Viral, bacterial, fungal and parasitic such as,Diseased Periodontium,Primary herpetic stomatitis,Candidal stomatitis,Neoplastic disease Supports basic, patient oriented, and community-based research on the etiology, pathogenesis and metastasis, epidemiology, prevention, diagnosis, treatment of oral and pharyngeal neoplastic diseases,Chronic disabling diseases,The full range of research involving chronic disabling disease associated with the craniofacial-oral-dental complex,This includes osteoporosis, osteoarthritis and related bone disorders, temporo-mandible joint diseases and disorders, neuropathies and neuro-degenerative diseases including those involving oral sensory and motor functions and autoimmune diseases such as sjgrens syndrome.,Chronic diseases of cran-oral-dental complex and other systemic diseases (e.g., diabetes),Biomaterials, biomimetics and tissue engineering,Biomaterials used for the repair, regeneration, restoration and reconstruction of craniofacial-oral-dental molecules,cells, tissues and organs,The study of computer aid design (CAD) computer aid manufacture (CAM) for denture,Behavior, health promotion and environment aimed at assessing the interactive roles of sociological, behavior, economic, environmental, genetic, and biomedical factors in craniofacial-oral-dental diseases and disorders,2019 Diet and Oral Health,caries,Cariology is a discipline within Stomatology which deals with the complex interplaying between the oral fluids and the microbial deposits in relation to subsequent changes in the dental hard tissues.,Epidemiology in dental caries,Several index have been used in dental caries,Prevalence=,No of the patients with caries,No of the specific population in an area at risk of getting caries at that time,Prevalence of caries: the total caries experience of a population in existence at a certain time in a designated area.,Caries incidence is usually expressed as the number of new decayed teeth or surfaces per-a period in a individual,group, or population.,Incidence of caries,DMF=Decayed teeth+Missing teeth+Filled teeth/Number of subjects examined,DMFT,If surface have been counted, then we refer to the score as DMF-S If the teeth have been counted, then it is refer to as DMF-T The DMF-S or DMF-T are often referred to as an “index”,The distribution of dental caries in oral cavity,Reducing tendency in developed country,The DMFT prevalence of 12-year-old children in the Nordic countries in the period 1974-91.Denmark,Finland ,Norway and Sweden seem to follow the same downward trend, whereas Iceland has started a more rapid decline somewhat later.,Increasing tendency in developing country,DMFTs for 12 Years-old in Part of developing country,The caries prevalence of China,Time Population people with caries prevalence Before 1949 32469 19258 59.30 19501959 219312 106781 48.70 19601969 544708 217774 40.00 19701979 3766290 1356362 36.00 131340 40.54,permanent teeth,Cities 25080 Countryside 20636,29.70,Cities 19683,79.55,Countryside 16253,58.48,Deciduous teeth,The DMFT prevalence of 12-year-old children in 11 provinces of China,Beijing 1.41 0.98 Shanghai 1.17 0.95 Tianjing 1.41 1.02 Gansu 0.36 0.8 Shandong 0.69 0.59 Yunnan 0.46 0.88 Liaoning 0.76 1.29 Zhejiang 1.22 1.46 Hubei 0.98 0.51 Guangdong 0.91 1.65 Sichuan 0.57 0.37 Account 0.67 0.88,Province DMFT(1983) DMFT(2019),Age DMFT 12 1.03 15 1.42 18 1.60 3544 2.11 6574 2.49 (DFT),The DMFT prevalence in 2019,Current concept of caries etiology,Dental caries is a multifactorial disease in which there is an interplay of three principal factors: the host (primarily the saliva and teeth), the microflora, and the substrate, or diet.,A fourth factor time must be considered in any discussion of the etiology of caries. Diagrammatically,these factors can be portrayed as four overlapping circles.,Micro- organisms,host & tooth,Sub- strate,The four circles diagrammatically represent the factors involved in the carious process.all four factors must act concurrently (overlapping of the circles)for caries to occur,time,no caries,no caries,no caries,no caries,caries,Caries requires a susceptible host, a cariogenic oral flora and a suitable substrate that must be present for a sufficient length of time,Etiology of Caries,Saliva,the term saliva refers to the mixture of secretions in the oral carity,Saliva is produced day and night and it is constantly swallowed Saliva is present as a proteinaceous film covering all surfaces of oral cavity,This mixture consists of fluids derived from the major salivary glands minor glands of oral mucose traces from gingival exudate,Effect of desalivation on incidence and extent caries in animals,Effect of desalivation on caries in hamsters,*Parotid, submandibular, and sublingual glands.,Decreased salivary flow and caries in humans,Sarcoidosis Sjogrens syndrome Tharapeutic radiation,Hydrogen ion Buffering ability Calcium Inorganic phosphate Fluoricle,Inorganic components,Organic components,mucins Glycoproteins Statherin and acidic proline-rich proteins amylase,Antrmicrobial proteins,Saliva and dental caries,the quantity of saliva associated with caries experience,Relationship between salivary characteristics and caries prevalence,Salivary composition and caries,Antibacterial factors of glandular origin could protect oral mucosal and hard surfaces by helping to regulate the quantity and species distribution of oral microbes,Oral Microorganisms and dental plaque,In contrast to mucosal surfaces, the surfaces of teeth are not constantly renewed by shedding of colonized epithelial cells.,Surfaces of teeth,Some special sites occlusal fissues Approximal surface,Dental deposits,Biofilms on dental surface-matrix-embedded microbial population, adherent to each other and/or to surface or interfaces,Acquired pellicle,Acellular, homogeneous organic film that forms on enamel and other hard surface by selective adsorption of salivary proteins.,adsorption of salivary proteins or glycoproteins,Origin,Immediately after cleaning and polishing, salivary secrete deposit in the defects of enamel.,Surface pellicle Subsurface pellicle,Histological appearance,The surface pellicle appears acellular and faintly granular under TEM,Surface Pellicle,Pellicles of unknown age may vary in thickness from 501000nm.,globular fibrillar granular,Different morphological types,A subsurface pellicle consisting of dendritic processes that spread into the intercrystalline spaces and extend to 3m into the enamel.,90% water 10% solid material,composition,According to chemical analyses amino acids account for 45% to 50% carbohydrates amount 10% to 15% of the dry weight lipid,Function,healing, repairing, or protecting the enamel surface imparting selective permeability to the enamel influencing the adherence of specific oral microorganisms to the tooth surface serving as a substrate or nutrient for the organisms,summary,Organic deposit Naturally forms by selective adsorption Origin of protein from saliva After polishing, reforms rapidly Bacteria settle on the pellicle as soon as it forms formation of dental plaque,Dental Plaque,In the fourth century B. C.,Aristotle related soft, adhere food deposits to tooth decay, but it was not until the advent of the microscope in the seventeenth century that “animalcules (microorganism) were seen in these dental deposits.,Anton van leeuwenhoek, a draper and sheriffs chamberlain in Delft recognized the limitation of mechanical oral hygiene in removing these deposits.,Anton Van leeuwenhoek saw large numbers of living cells in scrapings from teeth: I judge from myself that all the people living in our united Netherlands are not as many as the living animalcules that I carry in my own mouth this very day.,Terminology 1847 Ficinus a slime coating denticulate Williams demonstrated the presence of a mass of microorganisms 1895 G.V. Black gelatinous microbial plaque,Dental plaque,Most figurative description: a bacterial aspic with millions of organisms standing shoulder to shoulder,More formal definition by Le: plaque is the soft, non-mineralized, bacterial deposit which forms on teeth and dental prosthesis that are not adequately cleaned,Morphology of dental plaque A white or off-white accumulation Variable thickness,Three main typies of organisms coccoid rod-shaped filamentous,classification,Supragingival plaque Subgingival plaque Dental calculus (calcified plaque),Supragingival plaque,Smooth surface plaque Fissure plaque,Supragingival smooth surface plaque,Divided into 4 areas: plaque/tooth interface condensed microbial layer body of the plaque plaque surface,plaque/tooth interface,In some locations no pelicle,Higher magnification of plaque-enamel border. Microorganisms that divide in horizontal planes are in direct contact with enamel (1 30,000).,Condensed microbial layer,a layer of very densely packed coccoid organisms, from 320 cells thick,Part of a 7-day-old interdental plaque grown on enamel. The enamel matrix (bottom), appearing as a fine meshwork, is covered by a thin electron-dense and discontinuous pellicle. Immediately above this is the condensed microbial layer which is covered by a layer of coccoid and filamentous micro-organisms and probably Neisseria. The intermicrobial space is electron-lucent and reveals cell remnants ( 1 6,500).,Body of the plaque this occupies by far the largest portion of the plaque,Thin section of plaque made of different bacterial species-predominantly coccoidal.,Dense aggregation of microorganisms at the enamel surface (lower left),Plaque surface loosely arrangement Great variety: coccoid, rod like, “corncob”,In the surface layer of plaque some microorganisms co-aggregate with other species, as visualized by the presence of so-called corn cob structures,Magnified view of “corncob”,Free surface of plaque composed of unidentified organisms,Free surface of plaque composed of coccoid gram-positive (heavily stained cell walls ) and unidentified gram-negative microorganisms,Fissure plaque Gram-positive cocci and short rods predominate in a homogeneous,matrix, with occasional yeast cells,Palisade and branching filaments are absent within the fissures,A: survey of dental plaque situated within a deep, narrow fissure of a premolar B: the upper half of the fissure is filled with dark material, the lower half is les dense C: Higher magnification reveals a plaque consisting of mostly ghostlike membrane and cell wall structures,Subgingival plaque The matrix is sparse Organisms:filamentous organisms, bacilli, cocci, spirochetes Gram negative bacteria,The filamentous nature of plaque associated with gingivitis. Note attachment of smaller bacteria to filaments,Calcified plaque,Supragingival calcucus white chalky yellow,Sub gingival calculus greenish black,Dental calculus is plaque in which mineralization has involved both the plaque matrix and the microorganisms.,Formation and development of dental plaques,Uneven tooth surface Carious lesions ill-filling margins of restorations Irregularities in positioning of the teeth,the location favoring plaque formation:,Pellicle formation Microbial colonization,Process of formation,Plaque formation can be considered as three phases,Initial colonization Rapid bacterial growth Remodeling,Bacteria are thought to be unspecifically associated with the tooth surface und