Periodontal diseases

The Periodontium Libyan International Medical University 2nd Year First Semester D Caroline Piske de A. Mohamed

ObjectivesLearning issues and objectives:What is meant by periodontium? What are its various components?Describe the functions of periodontium and how they are performed.

PERIODONTIUM

Cementum

PDL

Alveolar bone

Sharpey's fibers

AttachmentorganCementumPeriodontalligamentAlveolar boneApical foramenPulp cavityEnamelDentinGingivaRoot canalAlveolar vessels& nerves7

FUNCTIONS OF PDLSUPPORT: PDL supports teeth in their socket. It prevents loosening of teeth.MASTICATORY LOAD: PDL permits teeth to withstand the considerable forces of mastication. SENSORY: PDL is supplied by abundant receptors and nerves that sense the movement when teeth are in function. Helps in the proper positioning of the jaws during normal function.NUTRITIVE: Blood vessels of ligament provide essential nutrients for the ligaments vitality and hard tissue of cementum and alveolar bone.Fibroblasts, osteoblasts, cementoblasts, and even resorptive osteoclasts and macrophages require nutrition.CLINICAL CORRELATION: Bone, PDL, and the cementum together form a functional unit of special importance when the orthodontic tooth movement is undertaken. Orthodontic forces causes compression and constriction of blood vessels, soft tissue changes occur.Hence loss of alveolar bone occurs, now blood flow occurs in the spaces. And the mesenchymal cells of PDL repair the tissues.

MAINTAINENCE: Tissues are maintained under the influence of heavy masticatory forces.ADAPTIVE ROLE

SHOCK ABSORBER: It absorbs the shock of chewing.

PRINCIPAL FIBER BUNDLES OF PDLTHE ALVEOLAR CREST GROUPThese are attached to the cementum just below the cementoenamel junction and running downward and outward to insert into the rim of the alveolus.

2.THE HORIZONTAL GROUP

These are just apical to the alveolar crest fibers and running at right angles to the long axis of the tooth from the cementum to the bone below the alveolar crest.

3. THE OBLIQUE GROUP

They are the most numerous in the PDL and running from the cementum in an oblique direction to insert into the bone coronally

4.THE APICAL GROUP:These are radiating from the cementum around the apex of the root to the bone forming the base of the socket.

5.THE INTERADICULAR GROUP

Found only in the multi-rooted teeth and running from the cementum into the bone forming the crest of the Interradicular septum.

TEETH IN-SITU19

TYPES OF CEMENTUMCEMENTUM is classified according to the presence or absence of cells within its matrix.CELLULAR CEMENTUM, which has an adaptive role in response to tooth wear and movement and is associated with repair of periodontal disease.ACELLULAR CEMENTUM, which provides attachment for the tooth.

A- CELLULAR CEMENTUMB-ACELLULAR CEMENTUM

Materia alba Bacterial aggregations, leucocytes and desquamated oral epithelial cells accumulating at the surface of plaque and teeth, but lacking the regular internal structure observed in dental plaque. ( mouth rinse can desegregate it) D Caroline Mohamed

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Dental plaqueDental plaque is the soft, nonmineralized bacterial deposit which forms on teeth and dental protheses that are not adequately cleaned. Le 1965Microscopically, plaque is simply confluent colonies of microorganisms connected by a matrix consisting predominantly of bacterial and salivary polymers. These accumulations subject the teeth and gingival tissues to high concentrations of bacterial metabolites, which result in dental disease. The dominant bacterial species in dental plaque are Streptococcus sanguis and Streptococcus mutans, both of which are considered responsible for plaque.

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Differences between materia alba, plaque and calculusD Caroline Mohamed52

Clinical appearanceComposition Internal structureAdherence strength

52Major sites of plaque accumulationFissures of molar teethSupragingival: on the tooth surface above the gingivaSubgingival: in the area bounded by the margin of the gum and the toothInterproximal: between adjacent teeth

Plaque formationPlaque formation is initiated by a weak attachment of the streptococcal cells to salivary glycoproteins forming a pellicle on the surface of the teeth. Bacteria adhere to the pellicle, and pellicle coats the enamel. The specific type of bacteria/pellicle adherence is determined by the innate characteristic of the bacteria and the pellicle. Gram positive rods and cocci are laid down in the first hour.

Time elapsed 1 hour

The initial bacteria are called pioneer colonizer, because they are hardy and successfully compete with other members of the oral flora for a place on the tooth surface.

56Primary colonizersD Caroline Mohamed57Generally the primary colonizers are not in sufficiet number to be pathogenic.Overwhelming cocci, specially streptococci and short rods.

Gram-positive facultatively anaerobic Streptococcus sanguis is most dominant first to appear followed later by S. Mutans. Actinomyces spp. are also found in 24h plaque. Gram-positive cocci and rods co-aggregate and multiply.58D Caroline MohamedThose bacteria depend for their grownt on a sheltered environment and the presence of an excess of extracellular carbohydrate (eg. sucrose) from wich they synthesize extracellular polysaccharides and gain an internal source of energy. The polysacharides coat the cell and help protect the cells from bursting from the osmotic effects of the sucrose. Also , the polysaccharide coating reduces the effect of the end products, such as latic acid and toxins, that can inhibit bacterial metabolism.58This is followed by a stronger attachment by means of extracellular sticky polymers of glucose (glucans) which are synthesized by the bacteria from dietary sugars (principally sucrose).

An enzyme on the cell surface of Streptococcus mutans, glycosyl transferase, is involved in initial attachment of the bacterial cells to the tooth surface and in the conversion of sucrose to dextran polymers (glucans) which form plaque.

Bacteria adhere, multiply and increase in mass and thickness and form mini colonies in layers upon the pellicle (plaque formed by rod and cocci only). Time elapsed 24-48 hours

D Caroline Mohamed59Within a short time, the tooth surface adjacent to the gingiva is covered by intermeshed bacteria.

New bacteria derived from saliva or surrounding mucous attach by a bonding interaction to bacteria already attached to the plaque. All this activity occurs within the first 2 days of plaque development and, for description purposes, is called phase I of plaque formation.

In phase II of plaque development, the outer surface of the plaque is covered by gram-positive tall rods.

There is a dramatic increase in plaque thickness 3 and 4 days compared to the first two days.

Secondary colonizers62D Caroline Mohamed

Adhere to bacteria already in the plaque mass. Surface receptors on the Gram-positive facultative cocci and rods allow the subsequent adherence of Gram-negative organisms, which have a poor ability to directly adhere to the pellicle. Fn: Fusobacterium nucleatum. BI: Prevotella intermedia.

They do not initially colonize the clean tooth surface but adhere to bacteria already in the plaque mass.

62Any area where the plaque has not been removed, either because of no home care or ineffective techniques, the bacteria mass continues to grow with a more complicated mixture of bacteria ( fusobacteria and filamentous).

As the plaque thickens at the cervical area, the deeper layers incorporate more filaments and fusiforms, eventually turning gram negative. The coronal plaque is a more simple early arrangement of rods and cocci.

Time elaped 4-7 days

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Micro-coloniesD Caroline Mohamed64About 2 days the plaque double in mass, cocos and rods64

Microcolonies coalescingD Caroline Mohamed65during this time the colonies have been coalescing.

65In phase III, 4 to 7 days after initiation, plaque begins to migrate subgingivally, and bacteria and their products permeate and circulate in the pocket. The heterogeneity increases as plaque ages and matures. As a result of ecologic changes, more Gram-negative strictly anaerobic bacteria (fusobacteria, veillonellae) colonize secondarily and contribute to an increased pathogenicity of the biofilm.

In phase IV, 7 to 11 days after initiation of plaque development, the diversity of the flora increases to comprise motile bacteria including spirochetes and vibrios as well as fusiforms and white blood cells appear.

The plaque becomes more gram negative and anaerobic in the deeper layers, the gums become slightly inflamed.

Time elapsed 7-14 days

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Vibrios and spiroquetes continue to multiply. The bacteria in the dental plaque become highly organized, filamentous, are perpendicular to the tooth surface, and pulsate in a palisade fashion. The signs of inflamed gums are obvious.

Time elapsed 14-21 days D Caroline Mohamed68

The increasing thickness of the plaque limits the diffusion of oxigen to the entrapped original oxigen-tolerant populations, as a result the organisms that survive in the deeper parts of the plaque are either facultative or obligate anaerobes as fusobacteria and veillonese

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FilamentousbacteriaD Caroline Mohamed70

corn-cob associations

D Caroline Mohamed71Arrangements of cocci as corn cob figures or test tube brushes71This mature plaque is now so packed with diverse bacteria that an exogenous species would have great difficulty becoming established in the overcrowded habitat.

With time, more bacteria migrate subgingivally, and the process continues more aggressively.

Clean substratumMolecular adsorption(Phase 1) Single organisms (Phase 2)Multiplication (Phase 3)Sequential adsorptionof organisms(Phase 4)73D Caroline MohamedMature dental plaqueD Caroline Mohamed74

Calculus Composition 1. inorganic content 70-90% of calcium phosphate, calcium carbonate, magnesium phosphate2.organic content protein-polysaccharide, desquamated epithelial cells, leukocytes, microorganisms

Calculus formationCalculus is dental plaque that has undergone miniralizationSoft plaque.......precipitation of miniral salts between 1st and 14 daysSaliva is the source of miniralizationGingival Cervicular Fluid (GCF)

Health

Gingivitis

PeriodontitisNormal dental plaque: coccis, filaments, epithelial cell, little motility

Gingivitis plaque: spirochetes and great motility

The critical locus of activity is the subgingival space (periodontal pocket).

The bacteria residing in the pocket and the host cells that defend it determine the clinical outcome.

The diseased periodontal pocket harbors both attached subgingival plaque biofilms and nonattaching, motile subgingival microflora (spirochetes, vibrios, and straight rods with flagella).

Orland et al (1954) demonstrated germ-free animals do not develop caries. In humans, when bacteria are allowed to accumulate in plaque on the tooth surfaces, enamel caries and gingivitis develop within 2 or 3 weeks.

Periodontal DiseaseHow do we know there is a problem?? DIAGNOSISIndividual complaineClinical examinationsRadiographic examinationIndividual complaine

Bleeding gumsRed gumsBlood on my piloBad taste Bad smell (halitosis)Smokers ....less bleeding

Clinical examinationsPlaque indexGingival indexPocket measurment Furcation Tooth mobility

Plaque Scoring System for Quigley and HeinScoreno plaque0flecks of stain at the gingival margin1definite line of plaque at the gingival margin2gingival third of surface3two thirds of surface4greater than two thirds of surface5Plaque Index

total score = = SUM(scores for all faal and lingual surfaces)index = = (total score) / (number of surfaces examined)

Gingival Index Le & Silness 1963

Score 0Score 2

Score 3

Score 1

Gingival Index: GI

0 1 2 3

AppearanceBleedingInflammationPointsnormalno bleedingnone0slight change in color and mild edema with slight change in textureno bleedingmild1redness, hypertrophy, edema and glazingbleeding on probing/pressuremoderate2marked redness, hypertrophy, edema, ulcerationspontaneous bleedingsevere3Gingival Index Le & Silness 1963

Gingival Index Le & Silness 1963

Teeth examined:(1) maxillary right first molar(2) maxillary right lateral incisor(3) maxillary left first bicuspid(4) mandibular left first molar(5) mandibular left lateral incisor(6) mandibular right first bicuspidSurfaces examined on each tooth:(1) buccal(2) lingual(3) mesial(4) distalGingival Index Le & Silness 1963

Average Gingival IndexInterpretation2.1 - 3.0severe inflammation1.1 - 2.0moderate inflammation0.1 - 1.0mild inflammation< 0.1no inflammationGingival Index Le & Silness 1963

Sign the worse scoreChoose the worse scoreSign the worse scoreSign the worse score