Chapter 17: Dental soft deposits, Biofilm , calculus & stains Flashcards
a thin, acellular tenacious film formed of proteins, carbohydrates, and lipids.
acquired pellicle
when does formation of pellicle formation begin
upon exposure to saliva
the pellicle begins to form and is fully formed within 30 to 90 minutes
composition of pellicle
glycoproteins, selectively adsorbed by the HYDROXYAPATITE of the tooth surface.
types of acquired pellicle
- subgingival
2. supragingival
clear, translucent, insoluble, and not readily visible until application of a disclosing agent.
supragingival pellicle
can become embedded in tooth structure, particularly where the tooth surface is partially demineralized or rough due to abrasion.
subgingival pellicle
The pellicle plays an important role in the maintenance of oral health as it :
protects, lubricates, and acts as a nidus of attachment for the bacteria and subsequent calculus on the tooth surfaces.
Extrinsic factors that may interfere with pellicle formation and maturation include:
- Abrasive toothpastes.
- Whitening products.
- acidic foods and beverages.
composed of microorganisms, their genetic make-up, and the environments found in the oral cavity.
microbiome
is a dynamic, structured community of microorganisms, encapsulated in a self-produced extracellular polymeric substance (EPS) forming a matrix around microcolonies
dental biofilm
composed of polysaccharides, proteins, and other compounds; it acts to protect the biofilm from the host’s immune system and antimicrobial agents.
matrix
referred to as acquired pellicle, dental biofilm,materia alba, food debris/
soft derposits
stages of biofilm formation
- formation
- bacterial multiplication
- matrix formation
- biofilm growth
- maturation
components of EPS
Polysaccharides
glucans
fructans or levans
dietary sucrose.
during this stage
Biofilm formation begins with initial attachment of planktonic bacterial cells to the pellicle on the tooth surface
during this stage of adhesion, the process is reversible.
stage 1 : Formation
during this stage Planktonic microorganisms attach themselves using cell adhesion structures such as fimbriae, pili, flagella, and adhesion proteins.
colonies produce EPS to firmly attach in an irreversible manner; rough surfaces will result in more rapid irreversible attachment.
stage 2- bacterial multiplication
during this stage Bacteria within the aggregate of cells continue to secrete EPS as bacteria multiply to form a matrix.
stage 3- matrix formation
provides a scaffold to anchor the bacteria together increasing adherence to dental and other structures and provide PROTECTION as the bacterial community continues to grow.
EPS
This stage is characterized by further development of the biofilm architecture to enhance the cell-to-cell communication process, also known as quorum sensing
stage 4 - biofilm growth
during this stage Bacterial colonies mature and release planktonic cells to spread and colonize other areas within the oral cavity
stage 5 - maturation
With undisrupted biofilm for approximately _ days, negative anaerobic bacteria growth is favored, which increased risk for dental ___ and _____
7
caries
gingivitis
on these days Early biofilm consists primarily of gram-positive cocci.
Streptococci, which dominate the bacterial population, include Streptococcus mutans and Streptococcus sanguinis.
1-2 days
on these days The cocci still dominate while increasing numbers of gram-positive filamentous form and slender rods join the surface of the cocci colonies along with more leukocytes.
2-4 days
on these days Filaments increase in numbers, and a mixed flora appears comprised of rods, filamentous forms, and fusobacteria with heavy accumulations of leukocytes
6-10 days
on these days gingivitis is clinically evident
10-21 days
organic elements of dental biofilm
- carbs
2. proteins
inorganic elements of dental biofilm
- calcium and phosporus
2. flouride
Biofilm plays a major role in the initiation and progression of dental caries and periodontal diseases, caused by _______ microorganisms found in oral biofilms.
pathogenic
Biofilm is significant in the formation of ________ , which is essentially mineralized dental biofilm.
dental calculus
The sequence of events leading to demineralization and dental caries is :
cariogenic foodstuff>dental biofilm>acid formation>demineralization>cavitated carious lesion.
Critical pH for enamel demineralization averages __
5.5
The critical pH for dentin is approximately __ to __ , which is especially relevant for patients with multiple areas of recession and xerostomia.
6.2, 6.4
Acid formation begins immediately once a cariogenic substance is taken into the biofilm,
t or f
true
a soft, whitish tooth deposit that is clinically visible without application of a disclosing agent. It may have a cottage cheese-like texture and appearance.
is an unorganized accumulation of living and dead bacteria, desquamated epithelial cells, disintegrating leukocytes, salivary proteins, and food debris.
materia alba
removal of materia alba
water spray, oral irrigator, or tongue action,
these stains occur on the external surface of the tooth and may be removed by procedures of toothbrushing, scaling, and/or polishing.
extrinsic
these stains occur within the tooth surface and cannot be removed by scaling or polishing. These stains may be improved by certain whitening procedures.
intrinsic
these type of stains develop or originate from sources outside the tooth. these stains may be extrinsic and stay on the outer surface of the tooth or intrinsic and become incorporated within the tooth structure
exogenous
these type of stains develop or originate from within the tooth. these stains are always intrinsic and usually are discolorations of the dentin reflected through the enamel.
endogenous
two broad categories for extrinsic stains
- Directed extrinsic stains caused by compounds, organic chromogens, attached to the pellicle producing a stain.
- Indirect extrinsic stains result from chemical interaction with the tooth surface that create a colored stain.
formation time of calculus
12 days but mineralization can begin as early as 24/48 hrs
Discolorations of the teeth and restorations occur in three general ways:
- Adheres directly to the surfaces.
- Contained within calculus and soft deposits.
- Incorporated within the tooth structure or the restorative material.
The lines between the layers of calculus are called ___________They form around the tooth in supragingival calculus, but they form irregularly from crown to apex on the root surface in subgingival calculus. The lines are evidence calculus grows or increases by apposition of new layers.
incremental lines
Calculus formation occurs in three basic steps:
- pellicle formation
- biofilm formation
- mineralization.
inorganic components of calculus
calcium, phosphorus, carbonate, sodium, magnesium
organic components of calculus
- microorganisms, -desquamated epithelial cells,
- leukocytes,
- mucin from saliva.
The difference between supragingival and subgingival calculus crystal is the calcium-to-phosphorus ratio is lower in supragingival calculus.
t or f
True
Calculus attachment is _______ because no interlocking or penetration occurs and calculus can be easily removed.
superficial
Distribution: Most Frequent Sites - supragingival calculus
lingual surfaces of mandibular anterior teeth and the facial surfaces of maxillary first and second molars,
Distribution - subgingival calculus
areas most difficult for the patient to access during personal oral biofilm removal procedures.
formation time of calculus
12 days but mineralization can begin as early as 24/48 hrs
Discolorations of the teeth and restorations occur in three general ways:
- Adheres directly to the surfaces.
- Contained within calculus and soft deposits.
- Incorporated within the tooth structure or the restorative material.
The lines between the layers of calculus are called ___________They form around the tooth in supragingival calculus, but they form irregularly from crown to apex on the root surface in subgingival calculus. The lines are evidence calculus grows or increases by apposition of new layers.
incremental lines
Calculus formation occurs in three basic steps:
- pellicle formation
- biofilm formation
- mineralization.
inorganic components of calculus
calcium phosphorus carbonate sodium magnesium
organic components of calculus
- microorganisms,
- leukocytes,
- mucin from saliva.
The difference between supragingival and subgingival calculus crystal is the calcium-to-phosphorus ratio is lower in supragingival calculus.
t or f
True
Calculus attachment is _______ because no interlocking or penetration occurs and calculus can be easily removed.
superficial
Distribution: Most Frequent Sites - supragingival calculus
lingual surfaces of mandibular anterior teeth and the facial surfaces of maxillary first and second molars,
Distribution - subgingival calculus
areas most difficult for the patient to access during personal oral biofilm removal procedures.
Biofilm located coronal to the gingival margin.
Supragingival biofilm
Biofilm that forms on the external surfaces of the oral epithelium and attached gingiva.
Gingival biofilm
located between the epithelial attachment and the gingival margin, within the sulcus or pocket.
Subgingival biofilm
develops in pits and fissures of the teeth.
Fissure biofilm
Detection of Biofilm
- Direct vision
- explorer & probe
- disclosing agent
- clinical record
results during mastication as food is forced into open contact areas due to mobility of teeth or occlusal irregularities such as plunger cusps.
Vertical food impaction
The enamel is partially or completely missing due to a generalized disturbance of the ameloblasts. Teeth are yellow to yellowish-brown
Amelogenesis imperfecta
The dentin is abnormal as a result of disturbances in the odontoblastic layer during development. The teeth appear translucent or opalescent and vary in color from gray to bluish-brown
Dentinogenesis imperfecta
results from damage to the tooth germ during development and the location of the defect(s) is typically related to the timing of the injury during development.37
Enamel Hypoplasia
originally called “brown stain.” Later, Dr. Frederick S. McKay studied the condition and described it in the dental literature as “mottled enamel.”
Dental Fluorosis
a primary risk factor for gingivitis, inflammatory periodontal diseases, and dental caries.
Dental biofilm
_______ calculus in maxillary molar areas tends to be high in calcium, phosphorus, and ash content than on the lingual of mandibular anterior teeth
Supragingival
Dental enamel is the most highly mineralized tissue in the body and contains __% to __% inorganic salts;
95-97
results from the deposition of minerals into a biofilm organic matrix.
Calculus
The source of elements for supragingival calculus is the _____.
Saliva
has a greater variability in architecture than subgingival biofilm and typically consists of TWO layers of predominantly gram-positive aerobic bacteria
Supragingival biofilm
is made up of four layers, which includes predominantly gram-negative anaerobic and motile organisms
Subgingival biofilm
