DENTPC 511 EXAM 1 STUDY GUIDE

Name the components of the periodontium

gingiva, periodontal ligament (PDL), alveolar bone, cementum 

Terms and functions for types of gingiva

marginal gingiva- surrounds tooth 

attached gingiva- attached to alveolar bone 

interdental papilla- between teeth 

Types of pdl and gingival fibers and function

gingival fibers: 

gingivodental: 

facial lingual interproximal

beneath epithelium

circular:

through connective tissue

transseptal 

interproximal:

between epithelium at the base of the gingival sulcus 

PDL fibers: 

alveolar crest fibers

prevent tooth extrusion, resist lateral tooth movement

oblique fibers

bear and transform brunt of vertical masticatory stress

transeptal fibers

over the alveolar bone crest, no osseous attachment

horizontal fibers

interradicular fibers

apical fiber

do not occur on incomplete formed roots 

Types of bone and location ??

alveolar bone

alveolar bone proper (lamina dura) 

cribiform plate

trabecular bone

supporting alveolar bone 

compact bone

formed by haversian bone and bone lamellae

Types of collagen and location

collagen fibers: 

lamina densa: type IV collagen

cementum: type 1 and type III

PDL: type 1 and type III

gingival fibers: type I

Types of cementum and location and characteristics

acellular/primary cementum 

cervical ⅓

formed before tooth reaches occlusal plane

more sharpeys fibers 

more calcified

cellular/secondary 

apical ⅔

formed after the tooth reaches occlusal plane 

less sharpeys fibers

less calcified 

Bone response to external force

Keratinized versus non-keratinized tissue in mouth

ortho-keratinized: no cell nuclei in stratum corneum 

para-keratinized: cell nuclei in stratum corneum

non-keratinized: no stratum corneum, no stratum granulosum 

Layers of epithelium

stratum corneum

stratum granulosum 

stratum spinosum 

stratum basale

Lymphatic drainage

submandibular lymphnode

submental lymph node

upper deep cervical lymph node

lower deep cervical lymph node

Risk: definitions, characteristics, and examples for each

Risk factors

diabetes

smoking 

pathogenic bacteria 

Risk determinants/background characteristics

genetic factors 

age gender

socioeconomic status 

stress

Risk markers/predictors

previous history 

bleeding on probing (BOP)

Risk indicators

HIV?AIDS

osteoporosis 

infrequent dental visits 

What is the ultimate goal of risk assessment?

determine the patient's risk of developing or progressing periodontal disease

How does smoking affect periodontal disease?

affects prevalence, extent and severity of disease

Effect of smoking on gingivitis and periodontitis

negative effects reversible 

gingivitis: 

decreases gingival inflammation

decreases bleeding 

periodontitis

increase prevalence and severity 

increase pocket depth

increase bone loss

e-cigarettes versus smoking

e-cigarettes less harmful

unlikely to exceed 5% of harm of smoking 

5 A’s

ask 

advise 

assess

assist

arrange

Diabetes and oral health

direct relationship with periodontitis 

increased risk with  poorly controlled diabetes

Oral manifestations of HIV

oral candidiasis

linear gingival erythema

oral hairy leukoplakia 

Kaposi sarcoma and other malignancies 

acute necrotizing ulcerative gingivitis 

necrotizing ulcerative gingivitis and periodontitis 

chronic periodontitis 

BOP as an indicator of disease

continuous absence of BOP is a reliable predictor of periodontal stability and health 

Plaque and Calculus

Timeline of colonization of the oral cavity

day 1: facultative and aerobic bacteria 

day 2: anaerobic bacteria detected

day 14: mature microbiota established in gut 

2 years: human microbiota formed 

after tooth eruption: more complex oral flora

Commensal versus pathogenic bacteria

commensal: beneficial help to keep pathogenic bacteria at bay

pathogenic: disease causing

Ecosystems/niches in the oral cavity

buccal mucosa 

gingiva 

palate

dorsum of tongue 

intraoral, suprogingival, hard surfaces

subgingival biofilm 

Plaque versus materia alba verus calculus

plaque: resiliant clear to yello-graish substance

bacteria and salivary glycoproteins

biofilm 

impossible to remove by rinsing 

materia alba: white cheeselike accumulation

salivary proteins and some bacteria 

easily displaced 

calculus: hard deposit that forms via mineralization of p[laque 

covered by unmineralized dental plaque

must be removed using dental tools 

Phases of formation of plaque

3 major phase 

1. formation of pellicle 

2. initial adhesion/attachment of bacteria 

3. colonization and plaque maturation 

Characteristics of supragingival and subgingival plaque

supragingival plaque: on tooth surface, aerobic

gram pos cocci on tooth surface

gram neg rods,filaments,spirochets on outer surface

subgingival plaque: in gingiva anaerobic

anaerobic bacteria 

some organisms penetrate soft tissue and dentinal tubules 

fast re-growth within 7 days

tooth associated: 

similar to supragingival 

deeper lless filamentous 

tissue associated: 

gram neg rods and coccis 

filaments, flagellated rods and spirochetes

Plaque formation within the dentition

faster in lower jaw

faster in molars

faster on buccal surface

faster interproximally 

Individual variables in plaque formation

salivary flow 

saliva induced aggregation 

diet 

chewing fibrous foods 

smoking 

Red complex bacterial species

P. gingivalis 

T. forsythia 

T. denticola

Characteristics of a biofilm

organized structure 

bound in lower layer by polysaccharide

nutrients run through fluid channels 

bacterial communication 

Relationship between oral and other microbiomes

Plaque hypotheses

non-specific: accumulation of plaque over time. host response and susceptibility with age. 

plaque is key to disease control 

specific: only certain plaque is pathogenic 

ecological plaque hypothesis: both total amount of plaque and specific microbe contribute to disease 

keystone pathogen hypothesis: specific pathogen in low abundance can disrupt periodontal microbiota and lead to dysbiosis 

Changes in composition following SRP

overall decrease in red complex, increase in actinomyces 

Microorganisms in health versus disease

periodontis: majority anaerobic gram neg rods 

health: majority facultative gram pos rods and cocci 

gingivitis: majority facultative gram neg rods and gram pos rods and cocci

Microorganisms in plaque – general

gram pos rods 

gram pos cocci

gram neg cocci 

after 4 days composition shifts towards anaerobic and gram neg 

Content of calculus

70-90% inorganic 

calcium phosphate

calcium carbonate 

magnesium phosphate 

⅔ inorganic crystalline 

hydroxypatite

magnesium whitlockite

octocalcium phospahte 

brushite

 Calculus formation

starts between 1st and 14th day of plaque formation 

calcification start as little as 4-8 hours 

begins on inner surface of plaque 

forms in layers 

Supra versus subgingival calculus

supragingival calculus 

located above gingival margin (on tooth) 

heaviest near majory salivary ducts 

mineral source from saliva 

moderately hard but easily removed 

subgingival calculus 

not site specific 

mineral sourced from GCF and inflammatory infiltrate

highest incidence on proximal surfaces 

brown to black 

dense, hard, tenacious

slower formation