Carranza Flashcards
What is the reported gingival sulcus depth?
Ch 3
1.8mm, range 0-6mm
What is the “col”?
Interdental gingiva that has a depression - identical to junctional epithelium (non-keratinized stratified squamous epithel)
Which of the following epithelial layers is composed of flat squamous cells (orthokeratinized):
a. stratum basale
b. stratum spinosum
c. stratum granulosum
d. stratum corneum
Ch 3
stratum corneum - flat squamous eosinophilic cells without nuclei (orthokeratinization)
all distinct keratinized epithelial strata in process of keratinization
What types of epithelium are reported to have Langerhans cells important for the local immune response?
Ch 3
Gingival epithelium and sulcular epithelium
not found in junctional epithelium
What layer connects the epithelium to underlying connective tissue, and what collegen type predominates?
Ch 3
basal lamina, type IV collagen
What type of epithelial cells make up sulcular epithelium?
Ch 3
Non keratinized
How many layers thick can junctional epithelium be?
Ch 3
20 layers stratified squamous nonkeratinizing epithelium
How is junctional epithelium formed?
Ch 3
formed by the confluence of the oral epithelium and the reduced enamel epithelium during tooth eruption
REE not essential for its formation; in fact, the junctional epithelium is completely restored after pocket instrumentation or surgery, and it forms around an implant
What are the turnover rates for palate/tongue/cheek oral epithelium and gingival epithelium?
Ch 3
5-6 days; 10-12 days respectively
The turnover of the junctional epithelium is 1 -6 days
What cells produce sulcular (crevicular) fluid?
Ch 3
The main route of the gingival fluid diffusion is through the basement membrane, through the relatively wide intercellular spaces of the junctional epithelium, and then into the sulcus
What are the 4 functions of crevicular/gingival fluid?
Ch 3
(1) cleanse material from the sulcus; (2) contain plasma proteins that may improve adhesion of the epithelium to the tooth; (3) possess antimicrobial properties; and (4) exert antibody activity to defend the gingiva.
What are the 6 types of PDL fibers?
Ch 3
transseptal, alveolar crest, horizontal, oblique, apical, and interradicular fibers
What amount of dentin thickness is thought to decrease chances of pulpitis?
Ch 46 Endo-perio lesions
2mm
Define a class 1 perio-endo lesion?
Ch 46 Endo-perio lesions
Primary endodontic comprmise causing secondary periodontal disease
Define class 2 perio-endo lesion?
Ch 46 Endo-perio lesions
Primary periodontisis with HBL that causes secondary pulpitis from apex
Define class 3 perio-endo lesion?
Ch 46 Endo-perio lesions
Too advanced to tell if primary endo or perio, or the two happen simultaneously
What are the two theories for shock absorption of the PDL?
Ch 3
Tensional theory - that ligament fibers tranfer the shock from tooth to bone
Viscoelastic theroy - extracellular fluid transfers the shock to the lacunae of bone, with ligaments playing secondary role
Where is the axis of rotation for single rooted teeth and multi-rooted teeth respectively?
Ch 3
Single: between apical third and middle third of the root
Multi: the bone between roots
What nerve endings are present in the PDL to sense pressure, tactile and pain sensations?
Ch 3
(1) free endings, which have a treelike configuration and carry pain sensation
(2) Ruffini-like mechanoreceptors, which are located primarily in the apical area
(3) coiled Meissner corpuscles and mechanoreceptors, which are found mainly in the midroot region
(4) spindle-like pressure and vibration endings, primarily apical
What are the two main sources of collagen fibers in cementum?
Ch 3
(1) Sharpey fibers (extrinsic, from fibroblasts) – Type III collagen appears to coat the type I collagen of the Sharpey fibers
(2) Intrinsic fibers of cementum
What is the inorganic content % of cementum?
Ch 3
45-50%
What is the alveolar process?
CH 3
the portion of the maxilla and mandible that forms and supports the tooth sockets (alveoli)
What are the histologic layers of the alveolar process?
CH 3
- An external plate of cortical bone is formed by haversian bone and compacted bone lamellae.
- The inner socket wall of thin, compact bone called the alveolar bone proper is seen as the lamina dura in radiographs.
- Cancellous trabeculae between these two compact layers act as supporting alveolar bone
What are the 4 events in bone resorption?
Ch 3
- Attachment of osteoclasts to the mineralized surface of bone
- Creation of a sealed acidic environment through the action of the proton pump, which demineralizes bone and exposes the organic matrix
- Degradation of the exposed organic matrix to its constituent amino acids via the action of released enzymes (e.g., acid phosphatase, cathepsin)
- Sequestering of mineral ions and amino acids within the osteoclast
What is bundle bone?
Ch 3
Bundle bone is the term given to bone adjacent to the periodontal ligament that contains a great number of Sharpey fibers. Localized within the alveolar bone proper
How does plaque biolfilm adhere to teeth?
Ch 8
Binding of the bacterial species to receptors of the pellicle, then creating a nascent surface and acting as a bridge for additional species
There are primary and secondary colonizing species – Biofilm maturation is a highly specific event that involves a nonrandom aggregation of different bacteria.
Above what surface roughness will plaque begin to adhere?
Ch 8
Ra ≈ 0.2 µm
However, smoothness below this threshold does not decrease plaque adherence more - tapers off once this smooth
How much more resistant to ABX are biolfilm bacteria?
Ch 8
Almost without exception, organisms in a biofilm are 1000 to 1500 times more resistant as compared with antibiotics in their planktonic state
Saliva contains many components of the oral cavity’s innate immune response. What do the follow components do?
Mucin
Histatins
Lactoferrin
Ch 7
Mucin - inhibits agglutination and therefore adherence of bacteria to form biofilm
Histatins - inhibit virulence factors, neutrolizes LPS
Lactoferrin - inhibit bacterial cell growth
Saliva also contains specific immunoglobulin A antibodies to periodontal pathogens
What antibody is largely present in saliva?
Ch 7
IgA
What produces gingival crevicular fluid? And what does it contribute to the immune system in the mouth?
Ch 7
postcapillary venules of the gingival plexus
brings in PMNs, Abs, and compelement (innate)
flow increases with inflammation
What are the 3 groups of gingival fibers?
Ch 3
Gingivodental
Circular
Transseptal
What are the 3 sources of blood for the gingiva?
Ch 3
Supraperiosteal arterioles
Vessels of the periodontal ligament
Arterioles
How does RANK/RANKL/OPG regulate bone resorption?
Ch 7
RANKL binds to RANK and stimulates osteoclast differentiation and activation. OPG antagonizes this action by binding to RANKL and preventing it from binding to RANK.
The ratio of RANKL to OPG is important, with studies reporting higher levels of RANKL and lower levels of OPG in patients with advanced periodontitis compared with healthy controls
What bacteria make up the red complex of the microbiome?
Ch 8
P. gingivalis, T. forsythia, and T. denticola
These are secondary colonizers
What are the components of calculus?
Ch 13
Inorganic:
76% calcium phosphate
3% calcium carbonate
4% magnesium phosphate
2% carbon dioxide
Organic content: protein– polysaccharide complexes, desquamated epithelial cells, leukocytes, and various types of microorganisms
Calculus consists of mineralized bacterial plaque that forms on the surfaces of natural teeth and dental prostheses
What are the differences between suprabony and infrabony pockets?
Ch 23
Suprabony: base of pocket above alveolar bone, pattern of bone loss horizontal, transeptal fibers are horizontal
Infrabony: base of pocket is below alveolar bone, pattern of bone loss is vertical, transeptal fibers are obliqued
What % of volume of the junctional epithelium do PMNs (neutrophils) reach to cause detachment?
CH 23
60%
The degree of leukocyte infiltration of the junctional epithelium is independent of the volume of inflamed connective tissue; thus this process may occur in gingiva with only slight signs of clinical inflammation.
What antibody is largely present in saliva?
Ch 7
IgA
What produces gingival crevicular fluid (GCF)?
Ch 7
Postcapillary venules of the gingival plexus
What does GCF contribute to the immune system in the mouth?
Ch 7
Flushing ability of bacteria in sulcus
Neutrophils
Antibodies
What is the predominant T cell in stable periodontitis?
Ch 7
CD4+ Helper T cells
What is the main antibody to periodontal pathogens?
Ch 7
IgG
What role does RANK and RANKL play in periodontal disease?
Ch 7
Binding of RANKL to RANK results in osteoclast differentiation and activation and thus bone resorption
Which of the following is not a definitive microbial virulence factor?
a) Fimbriae
b) Lipopolysaccharides (LPS)
c) Adhesins
d) eDNA
ch 7
d) eDNA
In the context of periodontal health, which immune response is central to the host response to periodontal pathogens?
Ch 7
Innate immune response
Which layer of the acquired pellicle is difficult to remove as observed under transmission electron microscopy?
A) Thin basal layer
B) Thick globular layer
C) Salivary layer
D) Hard tissue layer
Ch 8
A) Thin basal layer
Which phase of colonization of teeth by bacteria involves specific interactions between microbial cell surface adhesin molecules and receptors in the salivary pellicle?
A) Phase 1: Transport to the surface
B) Phase 2: Initial reversible adhesion
C) Phase 3: Strong attachment
D) Phase 4: Biofilm formation
Ch 8
B) Phase 2: Initial reversible adhesion
Which of the following complexes is associated with bleeding on probing?
Green complex
Orange complex
Yellow complex
Red complex
Ch 8
Red complex
What is the definition of Materia alba?
Ch 8
Soft accumulation of salivary proteins, some bacteria, many desquamated epithelial cells
How many times more is Biofilm bacteria more resistant to antimicrobial agents than their planktonic counterparts
Ch 8
1000 times more resistant
What bacterial species are considered to be the primary colonizers of a tooth surface?
A. Lactobacillus species
B. Steptococcus, Staphylococcus and Fusobacterium species
C. Steptococcus species, obligate aerobes and facultative anaerobes
D. Anaerobes including Actinomyces and Veiollenla
Ch8
C. Steptococcus species, obligate aerobes and facultative anaerobes
Which of the following statements accurately describes the inorganic composition in calculus?
A) Dental calculus primarily consists of hydroxyapatite, constituting approximately 58% of its content.
B) The major crystalline structure found in dental calculus is octacalcium phosphate.
C) Subgingival calculus exhibits a higher calcium-to-phosphate ratio compared to supragingival calculus.
D) Dental calculus comprises a significant amount of carbon dioxide.
Ch 13
A) Dental calculus primarily consists of hydroxyapatite, constituting approximately 58% of its content.
What is the major inorganic component of calculus?
a. sulfate
b. calcium phosphate
c. magnesium phosphate
d. calcium carbonate
Ch 13
b. calcium phosphate
Which of the following correctly differentiates supragingival and subgingival calculus?
A) Subgingival calculus contains less octacalcium phosphate than supragingival calculus.
B) The ratio of calcium to phosphate is lower in subgingival calculus.
C) The inorganic composition of subgingival calculus is similar to dental enamel.
D) Subgingival calculus is primarily composed of salivary constituents.
Ch 13
A) Subgingival calculus contains less octacalcium phosphate than supragingival calculus.
What % of calculus is inorganic?
CH 13
70-90%
What are the two most common locations for dental calculus to accumulate?
Ch13
Buccal aspect of caudal maxillary teeth and lingual aspect of rostral mandibular teeth
Which of the following drugs has been shown to have higher concentrations in GCF than serum?
A. Tetracyclines
B. Aminoglycosides
C. Cephalosporins
D. NSAIDs
Ch 16
A. Tetracyclines
Which of the following matches the salivary component with its function correctly?
A. Lysozyme → tooth integrity maintenance
B. Minerals → lubrication
C. IgA → cleansing
D. Bicarbonate and phosphate → buffering
Ch 16
D. Bicarbonate and phosphate → buffering
What is the probing depth of clinically normal gingival sulcus in humans
Chp 3
2-3mm
Nonkeratinized epithelium lacks what two key cellular structures?
Chp 3
No granulosum or corneum strata
How thick is the basal lamina?
Chp 3
300 to 400 A
What are the most to least keratinized oral mucosal structures?
Chp 3
Palate > gingiva > ventral aspect of tongue > cheek
How thick is oral epithelium?
Chp 3
- 0.3mm
This histo image depicts what type of gingival epithelium?
Chp 3
Keratinized
This histo image depicts what type of gingival epithelium?
Nonkeratinized
This histo image depicts what type of gingival epithelium?
Chp 3
Parakeratinized
What is sulcular epithelium composed of?
Cho 3
thin, nonkeratinized stratified sqaumous epithelium without rete pegs
What is the dentogingival unit?
Chp 3
The junctional epithelium and gingival fibers that attach the gingiva to the tooth
What is the definition of the gingival sulcus?
Chp 3
A shallow space that is coronal to the attachment of the junctional epithelium and bounded by the tooth on one side and the sulcular epithelium on the other. The coronal extent of the gingival sulcus is the gingival margin
What are the functions of gingival fibers and what are they composed of?
Type 1 Collagen
1.) To brace the marginal gingiva firmly against the tooth
2. To provide the rigidity necessary to withstand the forces of mastication without being deflected away from the tooth surface.
3. To unite the free marginal gingiva with the cementum of the root and the adjacent attached gingiva
What does gingival innervation derive from?
Chp 3
Fibers that arise from nerves in the PDL and the labial, buccal and palatal nerves
Principal fibers of the periodontal ligament are composed of what type of collagen?
Chp 3
Type 1 Collagen
What group of PDL fibers is most predominant?
Chp 3
Oblique fibers
What is the role of oxytalan fibers in the PDL?
Chp 3
They run parallel to the root surface in a vertical direction and bend to attach to cementum in the cervical third of the root.
Thought to regulate vascular flow in the PDL
The epithelial rests of Malassez are considered remanents of what developmental structure?
Chp 3
Hertwig root sheath
Proliferation of the epithelial rests of Malassez are associated with formation of what types of cysts?
Chp 3
Periapical and lateral root cysts
What are the two main sources of collagen fibers in cementum?
Chp 3
Sharpey fibers (extrinsic) –> embedded portion of the principal fibers of the PDL formed by fibroblasts
Fibers that belong to cementum matrix (intrinsic) produced by cementoblasts
Sharpey fibers are composed of what type of collagen?
Chp 3
Type I (90%)
Type III (~ 5%)
Type III thought to coat Type I fibers
When does acellular cementum form and what part of the tooth does it cover?
Chp 3
first cementum formed before tooth reaches the occlusal plane
Covers ~ the cervical third or half of the root
Sharpey fibers make up most of the structure of acellular cementum
What is cellular cementum?
Chp 3
formed after tooth reaches occlusal plane, more irregular and contains cells (cementocytes) in lacunae that communicate with canaliculi
Less calcified and occupied by smaller portion of cellular cementum arranged parallel to root surface or at random
What is the inorganic content (hydroxyapatite) of cementum, bone, enamel and dentin respectively?
Chp 3
Cementum 45-50%
Bone 65%
Dentin 70%
Enamel 97%
What is the most common morphology type of the cementoenamel junction in people?
Chp 3
Cementum overlapping enamel 60-65% of cases
What type of cementum is primarily responsible for the anchorage of the tooth in the alveolus?
Chp 3
Acellular extrinsic cementum
Lots of tightly packing Sharpey fibers
What cell surface receptors recognize LPS?
Ch 7
CD14, TLR-4, MD-2
Porphyromonas gingivalis has an atypical form of LPS that is recognized by both TLR-2 and TLR-4
What plaque bacteria metabolic waste products contribute directly to tissue damage?
Ch 7
ammonia, hydrogen sulfide, short chain carboxylic acids (butyric acid and proprionic acid), proteases
COX-2 is upregulated by what factors?
Ch 7
IL-1beta, TNF-alpha, bacterial LPS
Leads to increased production of PGE2
What prostaglandin has a major role in contributing to the tissue destruction of periodontitis?
Ch 7
PGE2
induces MMPs and osteoclastic bone resorption
What class of antibiotics possesses the ability to downregulate matrix metalloproteinases?
Tetracyclines
subantimicrobial doxycycline inhibits collagenase activity
What key proinflammatory cytokine up-regulates inflammatory respones and is produced by multiple cell types in the periodontium?
Ch 7
IL-1Beta
What are the key MMPs in periodontitis produced by neutrophils?
MMP-8 and MMP-9
What does IL-1Beta stimulate?
Ch 7
synthesis of PGE2, platelet-activating factor and nitrous oxide, ICAM-1 and IL-8
Tissue levels of IL-1Beta correlate with periodontal disease severity
What is the role of IL-1alpha in periodontal disease
Expressed intracellularlly normally –> becomes an alarmin when released from necrotic cells –> signaling cytokine for tissue damage
What is the role of Tumor Necrosis Factor Alpha (TNF-alpha) in periodontal disease?
Ch 7
Key inflammatory mediator –> increases neutrophil activity, mediates cell and tissue turnover by inducing MMP secretion. Stimulates development of osteoclasts and limits tissue repair by activated macrophages in response to LPS, activation of macrophage IL-1Beta production and induction of PGE2
Less potent effect on osteoclasts than IL-1Beta, present at lower levels in inflamed gingival tissue than IL-1Beta
What is the role of IL-6 in periodontal pathogenesis?
Ch 7
Secretion stimulated by IL-1Beta and TNF-alpha, stimulates bone resorption and development of osteoclasts
plays an important role but less than IL-1Beta or TNF-alpha
Bone resorbs to maintain a width of how much noninfiltrated connective tissue over the bone?
Ch 7
0.5 to 1.0mm
Bone resorption ceases when how many mm of distance is present between bacteria in the pocket and the bone?
Ch 7
2.5mm distance
What mediators stimulate osteoclastic bone resorption?
Ch 7
IL-1Beta, TNF-alpha, IL-6, PGE2
What does IL-8 stimulate?
Ch 7
neutrophil chemotaxis
How much bacteria does 1 gram of plaque contain?
Ch 8
10^11 bacteria
How much bacteria live in a healthy gingival crevice vs a deep periodontal pocket?
Ch 8
Healthy: 10^3 bacteria
Deep pocket: 10^8
What are the phases of plaque accumulation?
Ch 8
1.) The formation of the pellicle on the tooth surface
2.) The initial adhesion/attachment of bacteria
3.) Colonization/plaque maturation
Do bacteria adhere to enamel or the acquired enamel pellicle?
Ch 8
Acquired enamel pellicle
What species are considered the primary colonizers of the tooth surface?
Ch 8
Streptococcus (> 20% bacteria)
Haemophilus spp, Neisseria (obligate aerobes)
Actinomyces spp, Veillonella spp (facultative anaerobes)
facultative anaerobes can grow in the prsence or abscence of oxygen
What are the secondary colonizers of dental plaque?
Ch 8
Campylobacter spp, Fusobacterium nucleatum, Prevotella spp, Tannerella forsythia, Porphyromonas gingivalis
(Orange and red complexes)
How quickly does clinically visible plaque appear after stopping dental home care?
Ch 8
3 days
What role does quorum sensing play in plaque biofilm formation?
Ch 8
Modulates expression of genes for antibiotic resistance
encourages growth of beneficial spp in the biofilm
Discourages growth of competitors
What class of antibiotics is unaffected by the ion-exchange resin properties of the biofilm?
Ch 8
Macrolides
What mechanisms of antibiotic resistance have been demonstrated in plaque biofilms?
Ch 8
Conjugation (exchange of genes through direct interbacteria connection formed by sex pilus)
Transformation (movement of small pieces of DNA from environment into bacterial chromosome)
Plasmid transfer
Transposon transfer
What are the most common fungal spp isoloated from the human oral cavity?
Ch 8
Candida spp (C. albicans)
What is the nonspecific plaque hypothesis?
Ch 8
QUANTITATIVE
Periodontal disease results from elaboration of noxious products by the entire plaque flora.
Less plaque, less periodontal disease
Discarded in favor of other hypotheses. Treatment of perio still based on these principles
What is the Specific Plaque Hypothesis?
Ch 8
QUALITATIVE
The pathogenicity of dental plaque depends on the presence of or an incrase in specific microorganisms
Concept of red complex bacteria supported this hypothesis
What is the Ecologic Plaque Hypothesis?
Ch 8
COMBINATION
Both the total amount of dental plaque and the specific microbial composition of plaque may contribute to the transition from health to disease.
What is the Keystone Pathogen Hypothesis?
Ch 8
Certain low-abundance microbial pathogens can orchestrate inflammatory disease by remodeling a normally benign microbiota into a dysbiotic one.
P. gingivalis labeled keystone pathogen
What microbial shifts occur from health to periodontitis?
Ch 8
From gram-positive to gram-negative
From cocci to rods (at later stages to spirochetes)
Nonmotile to motile organisms
Facultative anaerobes to obligate anaerobes
Fermenting to proteolytic spp
What bacteria is considered the primary etiologic agent in most cases of localized aggressive periodontitis?
Ch 8
Aggregatibacter actinomycetemcomitans
Plaque becomes 50% mineralized in how many days?
2 days
Calcification can occur within as little as 4 to 8 hours
Drug induced gingival overgrowth can occur how soon after starting the associated medications (anticonvulsants, calcium channel blockers, immunosuppressants)?
Ch 19
3 months
What is the suggested etiopathogenesis of drug-induced gingival overgrowth?
Ch 19
DIGO medications affect the extracellular matrix metabolism by decreasing collagenase activity and increasing production of matrix proteins
Infiltration of what percent of the junctional epithelium by PMNs leads to apical migration of the junctional epithelium?
Ch 23
60% PMNs
