牙周病学课件：绪论病因

1、PERIODONTOLOGY Preface: Terminology & position2 Terminology3 Periodontal diseasesPeriodonticsPeriodontologyGingival diseasesPeriodontitis+Systemic diseasesPeriodontal medicineWhat is periodontal disease? Infectious disease of supporting tissue of teeth caused by bacteria One of the two most frequent

2、ly observed oral disease with prevalence of more than 90. Associated with multi-systemic disease and may impair systemic health and appearance of individuals . Be alert! No apparent signs and symptoms and is easily ignored. Can be effectively prevented and controlled.4 5 Source:The Effect of Periodo

3、ntal Disease on Medical and Dental Costs in a Middle-Aged Japanese Population, JOP, 2007 Shared risk factor of many systemic disease, endanger our health Extensive coverage Influence medical and dental expense Deep misunderstanding academically and therapeutically Basis of other dental specialtyThe

4、goal of periodontal treatment.6 Why the course should be highly valued? 10 PeriodonticsEndodonticsProthodonticsImpantology Oral maxilla surgeryOrthodontics Chapter 1: Anatomy of Periodontium 11 Healthy periodontium12 13 The periodontium consists of investing and supporting tissues of the toothGingiv

5、a : protection of the underlying tissuesAttachment apparatus: periodontal ligament, cementum, and alveolar boneThe periodontium is subject to morphologic and functional variations as well as changes associated with ageNormal periodontium14 The gingiva is the part of the oral mucosa that covers the a

6、lveolar processes of the jaws and surrounds the necks of the teeth. It is divided anatomically into marginal, attached, and interdental areas.What is Gingiva?15 The marginal, or unattached gingiva is the terminal edge or border of the gingiva surrounding the teeth in collarlik fashion The attached g

7、ingiva is continuous with the marginal gingiva. It is firm, resilient, and tightly bound to the underlying periosteum of alveolar bone.The interdental gingiva occupies the gingival embrasure which is the interproximal space beneath the area of tooth contactGingivaGingivagingival papilla attached gin

8、giva free gingiva 2022/7/2416 oral epithelium sulcular epithelium junctional epithelium Epithelium Dental gingival junction17 Gingival sulcus is the shallow crevice or space around the tooth bounded by the surface of the tooth on one side and the epithelium lining the free margin of the gingiva on t

9、he other.The mucogingival junction is the junction that demarcate the attached gingiva and alveolar mucosa18 Gingival Sulcus & The Mucogingival Junction2022/7/2419 The dimension of the soft tissue from the alveolar bone to the apical extent of the junctional epithelium. In the average patient, this

10、2- to 3-mm distance remains constant in health and disease. Encroachment on the biological width by restorations often leads to a series of events that result in the formation of periodontal pockets. The Biological Width20 How is the disease developed？21 GingivitisPeriodontitisHealthy teeth and gum2

11、2Disease development23 Chapter 2: ClassificationClassification: 1999 (American Academy of Periodontology) Gingival disease Periodontal disease Developmental or acquired deformities or conditions affecting periodontium2022/7/2424 Gingival diseasePlaque-induced gingival diseasePlaque-induced gingival

12、disease with local contributing factorsPlaque-induced gingival disease with systemic contributing factorsNon-plaque-induced gingival lesions25 治疗前治疗后8周Plaque-induced gingival disease治疗前治疗后8周孙, 女，34Y，初诊时间：20120416急性白血病Plaque-induced gingival disease with local contributing factors of leukemiasPlaque-

13、induced gingival disease with systemic contributing factors of diabetes Non-plaque-induced gingival lesions疱疹性龈炎浆液性龈炎扁平苔鲜遗传性牙龈纤维瘤病2008-6-1631Chronic periodontitisAggressive periodontitisNecrotizing ulcerative periodontitisAbscesses of the periodontiumCombined periodontic-endondontic lesionsPeriodont

14、itis as a manifestation of systemic diseases33 Periodontitis2008-6-1634掌跖角化牙周破坏综合症 Papillon-Lefevre syndrome Downs 综合症 Downs syndrome白细胞黏附缺陷症 leukocyte adhesion deficiency嗜中性白细胞减少症 Familial and cyclic neutropeniaPeriodontitis as a manifestation of systemic diseases2008-6-1636局部牙齿因素釉珠 Cervical enamel

15、 projection (20%)腭侧沟 Palatogingival grooves (8.5%)牙排列异常 Tooth malalignment邻面沟 Proximal root grooves开牙合 Open contacts不良修复体 Defect dental restoration 根折 root fracture 颈部磨损 Cervical root resorption and cemental tears 膜龈异常 Mucogingival deformities and conditions 缺乏角化龈 Lack of keratinized gingiva 龈退缩 Gin

16、gival recession 系带异常 Aberrant frenum2008-6-164344 Chapter 3: Etiology of Periodontal disease Infection with bacterial infiltration Destruction of periodontal tissues and pockets formation Destruction of alveolar bone 45health 3.5 mm PERIODONTAL DISEASE How Should We Understand Etiology of Periodonta

17、l Diseases? The clinical manifestations of periodontal disease result from a complex interplay between the etiologic agents Bacterial plaque is the etiologic factor responsible for inducing the host inflammatory process Increased plaque accumulation results from ineffective oral hygiene and is furth

18、er complicated by the presence of local factors such as calculus overhanging dental restorations or crowded and malaligned teeth46 How Should We Understand Etiology of Periodontal Diseases?47 The host response to bacterial plaque is influenced by the individuals genotype, or genetic makeup, and by e

19、nvironmental influences Host factors may act locally in reducing resistance to periodontal tissue destruction as a result of bacterial challenge, and the bacterial challenge may produce local or systemic responses that contribute to a systemic disease48 Periodontitis is the bacterially infected, inf

20、lammatory disease. Host defense system is critical for hosts susceptibility to infection. Inflammatory mediators, including PGE2, IL-1, TNF- and MMPs play the key roles in the pathogenesis of periodontitis.49 Pathogenesis of Periodontitis An individual may have increased susceptibility due to differ

21、ent factors; Gene polymorphisms associated with increased susceptibility may be quiet heterogeneous; An individual with increased susceptibility may be influenced by multiple genes (major effect genes, minor effect genes).50 Pathogenesis of Periodontitis51 Dental Plaque - Initiator It was found thro

22、ugh epidemiologic studies that the severity of gingivitis and the amount of alveolar bone loss were positively related to the amount of dental plaque.The clinical studies indicated that removing dental plaque mechanically and chemically is the effective way to treat periodontal diseases.52 Dental Pl

23、aque - InitiatorDental plaque can be defined as the soft deposits that form the biofilm adhering to the tooth surface or other hard surfaces in the oral cavity , including removable and fixed restorations.Supragingival plaque and subgingival plaque53 What is dental plaque? 54 Dental Plaque Formation

24、 of the dental pellicleAll surfaces of the oral cavity are coated with a glycoprotein pelliclePellicle forms by selective adsorption of the environmental macromoleculesPellicle function as a protective barrier, providing lubrication and preventing tissue desiccation Initial colonization of the tooth

25、 surface The initial colonizer are gram+ facultative bacteriaThe plaque mass then mature through the growth of attached species Secondary colonization and plaque maturationSecondary colonizers are the microorganisms that do not initially colonize clean tooth surfaces55 Formation of Dental PlaquePlaq

26、ue & Periodontal Disease Microbial Specificity of Periodontal Diseases Nonspecific Plaque Hypothesis Specific Plaque Hypothesis56 In the mid-1900s, periodotnal disease was believed to result from an accumulation of plaque over time in conjunction with a diminished host response and increased host su

27、sceptibility with age Some individuals with considerable amounts of plaque and calculus, as well as gingivitis, never developed destructive periodontitis. Patient with periodontitis demonstrated considerable site specificity. In the presence of uniform host response, these findings were inconsistent

28、 with the concept that all plaque was equally pathogenic.57 Plaque & Periodontal Disease Periodontal disease results from the “elaboration of noxious products by the entire plaque flora” Inherent in the hypothesis is the concept that control of periodontal disease depends on control of the amount of

29、 plaque accumulation. Much clinical treatment is still based on the nonspecific plaque hypothesis 58 Nonspecific Plaque Hypothesis Only certain plaque is pathogenic, and itspathogenicity depends on the presence of or increase in specific microorganisms Acceptance of the hypothesis led to a series of

30、 association studies focused on identifying specific periodontal pathogens by examining the microbiota associated with states of health and disease 59 Specific Plaque HypothesisA. Actinomycetemcomitans (Aa)Porphyromonas. gingivalis (Pg)Tannerella forsythia (Tf)Campylobacter recta (Cr)Prevotella inte

31、rmedia (Pi)Eubacterium nodatumFusobacterium. nucleatum (Fn)Streptococcus intermedius Prevotella nigrescens (Pn)Treponema denticola (Td)60 The most suspected periodontal pathogens61 Dental Calculus and Other Predisposing Factors Dental calculus is a hard deposit and consists of mineralized bacterial

32、plaque that forms on the surfaces of natural teeth and dental prosthesis. It is generally covered by a layer of unmineralized plaque. Etiologic significance: A positive correlation between the presence of calculus and the prevalence of gingivitis exists. The nonmineralized plaque on the calculus sur

33、face is the principal irritant, but the underlying calcified portion may be a significant contributing factor. It does not irritate the gingiva directly but provides a fixed nidus for the continued accumulation of plaque and retains it in close proximity to the gingiva. 62 Dental Calculus Materia al

34、ba is a concentration of microorganisms, desquamated epithelial cells, leukocytes, and a mixture of salivary proteins and lipids, with few or no food particles, and it lacks the organized structure of dental plaque and easily displaced with a water spray. It is yellow or grayish-white, soft, sticky

35、deposits. Dental stains: pigmented deposits on the tooth surface. Stains are primarily an aesthetic problem and do not cause inflammation of the gingiva.63 Materia alba, food Debris, and Dental stains Iatrogenic Factors Food impaction Malocclusion Orthodontic therapy Extraction of impacted third mol

36、ars Habits and self-inflicted injuries Tooth brush trauma Chemical irritation Tobacco useTooth Anatomic Factors64 Other Predisposing Factors Definition: inadequate dental procedures that contribute to the deterioration of the periodontal tissues Defect Restoration Margins of Restorations Contours/Op

37、en Contacts Restorative material Design of removable partial dentures Restorative dentistry procedures Orthodontic therapy plaque retention and composition Tissue response to orthodontic forces Extraction of impacted third molars65 Iatrogenic Factors Margins of restorations: subgingival margins are

38、associated with large amounts of plaque, more severe gingivitis, and deeper pockets (subgingival margins typically have a gap of 20 to 40 microns between the margin of the restoration and the unprepared tooth )Contours/open contacts : overcontoured crowns and restorations tend to accumulate plaque a

39、nd possibly prevent the self-cleaning mechanisms of the adjacent cheek, lips, and tongue 66 Defect Restoration Plaque retention and composition orthodontic appliances not only tend to retain bacterial plaque and food debris, but also are capable of modifying the gingival ecosystem. Tissue response t

40、o orthodontic forces Moderate orthodontic forces ordinarily result in bone remodeling and repair, excessive force may produce necrosis of the periodontal ligament and adjacent alveolar bone and increase the risk of apical root resorption. It is important to avoid excessive force and too rapid tooth

41、movement in orthodontic treatment.67 Orthodontic Therapy Definition: is the forceful wedging of food into the periodontium by occlusal forces. As the teeth wear down, their originally convex proximal surfaces become flattened and the wedging effect of the opposing cusp is exaggerated . Causative fac

42、tors: uneven occlusal wear, opening of the contact point as a result of loss of proximal support or from extrusion, congenital morphologic abnormalities, and improperly constructed restorations 68 Food impaction Trauma from occlusion: can be defined as resultant tissue injury when occlusal forces ex

43、ceeds the adaptive capacity of the tissues. Traumatic occlusion is an occlusion that produces such injury Acute trauma from occlusion results from an abrupt occlusal impact Chronic trauma often develops from gradual changes in occlusion produced by tooth wear, drifting movement, and extrusion of tee

44、th, combined with parafunctional habits such as bruxism and clenching.69 Traumatic occlusion & trauma from occlusion70 300 million smokers in China 1900 cigarettes a person per year 50 million 20 yr-olds young people will die from smoking-related diseases in the future 10.9% of all mortality rate ar

45、e from smoking-WHO Smokers are 2.6 to 6 times more likely to develop periodontal disease than non-smokers71 Tobacco Use72 Level of Probing Attachment LossPack/yearCorrelation between PD severity and Degree of smoking(pack-year) Microbiology: Smokers have a greater extent of colonization by periodont

46、al pathogens than nonsmokers or former smokers and that this colonization may lead to an increased prevalence of periodontal breakdown. Immunology: smoking may impair the response of neutrophils to periodontal infection but may also increase the release of tissue-destructive enzymes. Physiology: the

47、 presence of significant alterations in the gingival microvasculature of smokers when compared with nonsmokers and that these changes lead to decreased blood flow and decreased clinical signs of inflammation.73 The Mechanisms Nutritional influences effect of nutrition on oral microorganisms fat-soluble vitamin deficiency water-soluble vitamin deficiency protein deficiency Endocrine disordersdiabetessex hormonesneutrophil functions Osteoporosis Hematologic disorders Immunodefiency disorders Psychological disorders74 Influence of syst