Post on 22-Mar-2016
description
Periodontal DiseasePeriodontal Disease DefinitionDefinitionAn inflammatory disease of the An inflammatory disease of the
supporting tissues of the teeth supporting tissues of the teeth caused by specific microorganism, caused by specific microorganism, resulting in progressive destruction resulting in progressive destruction of the periodontal ligament and of the periodontal ligament and alveolar bone with pocket formation, alveolar bone with pocket formation, recession or both.recession or both.
Periodontal StructuresPeriodontal Structures Attachment Attachment
Apparatus:Apparatus:
CementumCementum BoneBone PPeriodontal eriodontal
ligamentligament
Periodontal MicrobiologyPeriodontal Microbiology 1960’s1960’sSpirochete Spirochete might be the cause of acute might be the cause of acute
necrotizing ulcerative gingivitis necrotizing ulcerative gingivitis (ANUG)(ANUG)
Actinobacillus actinomycetemcomitans Actinobacillus actinomycetemcomitans (A.A.) possible pathogen in localized (A.A.) possible pathogen in localized aggressive periodontitisaggressive periodontitis
Porphyromonas Gingivalis Porphyromonas Gingivalis suggested to suggested to be important in chronic periodontitis. be important in chronic periodontitis.
Complexity of the Complexity of the problemproblem
Technical difficultiesTechnical difficulties
Taking of the plaque samplesTaking of the plaque samples
Uncontaminated samples Uncontaminated samples Laboratory diagnosisLaboratory diagnosis CultivationCultivation
Inadequate understanding of Inadequate understanding of Disease PathogenesisDisease Pathogenesis
Misclassification of the disease type and statusMisclassification of the disease type and status
Disease due to different species at different sitesDisease due to different species at different sites
SuccesiveSuccesive episodes of disease due to different episodes of disease due to different speciesspecies
MistakenMistaken conclusion of samples taken from sites conclusion of samples taken from sites in remissionin remission
Pathogens may result from the disease Pathogens may result from the disease rather than the causerather than the cause
Two or more species act together and cause Two or more species act together and cause diseasedisease
The carrier state of disease can represent a The carrier state of disease can represent a
long lag phase prior to detection of diseaselong lag phase prior to detection of disease
Differences in clonal typesDifferences in clonal types
Complexity of the Complexity of the ProblemProblem
Approach to Determining Approach to Determining Etiologic AgentsEtiologic Agents
Koch’s Postulates:Koch’s Postulates:
1) 1) The agent must be The agent must be routinely isolatedroutinely isolated from diseased from diseased individualsindividuals and and recovered from cases of recovered from cases of other forms of other forms of diseasedisease or or healthy individualshealthy individuals
2) 2) The agent mustThe agent must be isolated as a be isolated as a pure culturepure culture
3) 3) Produce a similar diseaseProduce a similar disease when inoculated into when inoculated into susceptible laboratory animalssusceptible laboratory animals
4) 4) The agent must beThe agent must be re-re-isolatedisolated from infected animal from infected animal
Approach to Determining Approach to Determining Etiologic AgentsEtiologic Agents
In recent years, periodontal researchers In recent years, periodontal researchers have extended Koch’s postulates including:have extended Koch’s postulates including:
AssociationAssociation Requires that suspected pathogenic species be more Requires that suspected pathogenic species be more
frequently detected and at higher level in cases than in frequently detected and at higher level in cases than in the controlsthe controls
EliminationElimination Successful therapy will diminish the level of a pathogen Successful therapy will diminish the level of a pathogen
and and stopstop disease progression disease progression Host responseHost response
the organism must have high levels of serum, salivary the organism must have high levels of serum, salivary and gingival fluid antibody against it in periodontally and gingival fluid antibody against it in periodontally diseased subjectsdiseased subjects
Approach to Determining Approach to Determining Etiologic AgentsEtiologic Agents
Virulence factorsVirulence factors the organism must be found to produce the organism must be found to produce
virulence factors in vitro which can be virulence factors in vitro which can be correlated with clinical histopathologycorrelated with clinical histopathology
Animal PathogenicityAnimal Pathogenicity the organism must mimic similar pathogenic the organism must mimic similar pathogenic
properties in an appropriate animal modelproperties in an appropriate animal model
Evolving ConceptsEvolving Concepts
Active Disease
Absence of Beneficial Species
Presence of Pathogens
Susceptible Host
Destructive Periodontal Disease
Evolving ConceptsEvolving ConceptsSusceptible HostSusceptible Host
Impaired NeutrophilsImpaired Neutrophils Inadequate or unregulated Inadequate or unregulated
immunological responseimmunological response LPS ResponsivenessLPS Responsiveness AIDSAIDS DiabetesDiabetes SmokingSmoking DrugsDrugs
Evolving ConceptsEvolving ConceptsPresence of PathogensPresence of Pathogens
AActinobacillusctinobacillus actinomycetemcomitans actinomycetemcomitans T. forsythusT. forsythus EEikenellaikenella corrodens corrodens FFusobacteriumusobacterium nucleatum nucleatum PPeptostreptococcuseptostreptococcus micros micros PPorphyromonasorphyromonas gingivalis gingivalis PPrevotellarevotella intermedia intermedia CCampylobacterampylobacter rectus rectus Selenomonas sp.Selenomonas sp. Eubacterium sp.Eubacterium sp. SpirochetesSpirochetes
Evolving ConceptsEvolving ConceptsAbsence of Beneficial speciesAbsence of Beneficial species
Actinomyces sp Actinomyces sp CCapnocytophagaapnocytophaga ochracea ochracea
[] C. ochracea; [] C. ochracea; [] P. gingivalis [] P. gingivalis Diminished attachment lossDiminished attachment loss
S. mitisS. mitis S. mitis produces HS. mitis produces H22OO22
Kills A. a.Kills A. a. SStreptococcustreptococcus sanguis sanguis VVeillonellaeillonella parvula parvula
Porphyromonas gingivalis
Treponema denticola
Tannerella forsythensis
(Bacteroides forsythus )
Campylobacter rectusCampylobacter. showaeEubacterium nodatumFusobacterium nucleatumPrevotella intermediaPeptostreptococcus microsPrevotella nigrescens
Capnocytophaga spp.
Eikinella corrodens
A. actinomycetemcomitans
Veillonella parvula
Actinomyces odontolyticusS. mitis
S. oralisS. sanguisS. gordoniiS. intermedius
Microbial Complexes in Subgingival PlaqueMicrobial Complexes in Subgingival Plaque
Role of Disease Role of Disease SusceptibilitySusceptibility
Microbial species unevenly distributed from Microbial species unevenly distributed from subject to subject and from site to sitesubject to subject and from site to site
Subjects with widespread disease had more Subjects with widespread disease had more sites showing new attachment loss than sites showing new attachment loss than subjects with fewer affected sites at baselinesubjects with fewer affected sites at baseline
Percentages of suspected pathogens is highest Percentages of suspected pathogens is highest in subjects with localized destruction and in subjects with localized destruction and lowest in widespread disease subjectslowest in widespread disease subjects
Subjects with widespread disease and high Subjects with widespread disease and high levels of suspected pathogens had a greater levels of suspected pathogens had a greater number of active sites than subjects in other number of active sites than subjects in other groupsgroups
Bacterial interactions Bacterial interactions Different types of microorganisms Different types of microorganisms
existing in periodontal pockets may existing in periodontal pockets may act synergistically to induce disease act synergistically to induce disease progressionprogression
Bacterial interactions may be Bacterial interactions may be beneficial to the hostbeneficial to the host
Virulent Clonal Types of Virulent Clonal Types of PathogensPathogens
Multiple clonal types within a Multiple clonal types within a pathogenic speciespathogenic species
Clonal types differ in pathogenicity Clonal types differ in pathogenicity (A.a.)(A.a.)
Some clonal types are associated Some clonal types are associated with health and others with diseasewith health and others with disease
Regulation by the Local Regulation by the Local EnvironmentEnvironment
Strains of many species may turn Strains of many species may turn virulence factors “on/off”, depending on virulence factors “on/off”, depending on the nature of their environment:the nature of their environment: TemperatureTemperature
subgingival subgingival new attachment loss (appears) new attachment loss (appears)
Iron [ ]Iron [ ] CalciumCalcium MagnesiumMagnesium Osmolarity Osmolarity
ConclusionsConclusions For a disease to result from a pathogen:For a disease to result from a pathogen:
Be a virulent clonal typeBe a virulent clonal type Must possess chromosomal/extrachromosomal Must possess chromosomal/extrachromosomal
genetic factors to initiate diseasegenetic factors to initiate disease Host must be susceptible to pathogensHost must be susceptible to pathogens Pathogen must be in numbers sufficient to exceed Pathogen must be in numbers sufficient to exceed
threshold for the hostthreshold for the host Must be located in the right placeMust be located in the right place Other bacterial species must foster or at least not to Other bacterial species must foster or at least not to
inhibit the processinhibit the process Local environment must be favorable to disease Local environment must be favorable to disease
expressionexpression