Chapter 17 Flashcards
(138 cards)
1
Q
a community of microorganisms in micro colonies that grows on surfaces within the mouth, which is a primary risk factor for gingivitis, inflammatory periodontal diseases, and dental caries.
A
Dental biofilm
2
Q
During clinical examination of the teeth and surrounding soft tissues, soft and hard deposits are assessed. The presence of dental biofilm is a primary risk factor for
A
gingivitis, inflammatory periodontal diseases, and dental caries.
3
Q
What deposits are considered soft deposits?
A
acquired pellicle
dental biofilm
materia alba
food debris.
4
Q
What is acquired pellicle?
A
a thin, acellular, tenacious film formed of proteins, carbohydrates and lipids uniquely positioned at the interface between the tooth surfaces and the oral environment. It forms over exposed enamel, dentin, mucosa, and restorative materials.
5
Q
What are the types of Acquired Pellicle?
A
Acquired enamel pellicle and acquired dentin pellicle
6
Q
What are the functions of pellicle?
A
- Regulation of mineral homeostasis as the pellicle structure may serve as a scaffold for remineralization so it protects against acid-induced enamel demineralization and erosion.
- Host defense and microbial colonization
About 8% of the proteins in the pellicle have antimicrobial functions. - Lubrication: Pellicle keeps surfaces moist and prevents drying, which in turn enhances the efficiency of speech and mastication.
7
Q
How can a pellicle be removed?
A
At home, oral self-care regimen can easily remove and interfere with pellicle formation. Intake of acidic foods and drinks can also interfere with formation of
8
Q
What is an oral microbiome?
A
The complex community of microbes composed of bacteria, fungi and so on and their genetic makeup inhabiting the different environments in the oral cavity
9
Q
the only nonshedding surface in the body that serves as a unique environment for biofilm formation and maturation.
A
The permanent teeth
10
Q
Dental biofilm is a
A
dynamic, structured community of microorganisms, encapsulated in a self-produced extracellular polymeric substance (EPS) forming a matrix around microcolonies.
11
Q
____ Adheres to the pellicle coating on all hard and soft oral structures, including teeth, existing calculus, and fixed and removable restorations.
A
Dental biofilm
12
Q
The potential for the development of dental caries and/or gingivitis increases with _______in dental biofilm
A
more pathogenic microorganisms
13
Q
In the distribution of oral biofilm, what are the locations of biofilm?
A
• Supragingival biofilm: Coronal to the gingival margin.
• Gingival biofilm: Forms on the external surfaces of the oral epithelium and attached gingiva.
• Subgingival biofilm: Located between the epithelial attachment and the gingival margin, within the sulcus or pocket.
• Fissure biofilm: Develops in pits and fissures of the teeth.
14
Q
What are the factors that may increase accumulation of biofilm?
A
crowded teeth
Rough surfaces
Malocclusion
15
Q
Removal of Biofilm
____are the most universal daily mechanical disruption methods.
A
Toothbrushing and interdental cleaning
16
Q
What can be used for detection of oral biofilm?
A
A. Direct Vision
B. Use of Explorer or Probe
C. Use of Disclosing Agent
D. Clinical Record
17
Q
Biofilm plays a major role in the initiation and progression of___, caused by____
A
dental caries and periodontal diseases; pathogenic microorganisms found in oral biofilms.
18
Q
Biofilm is significant in the formation of dental calculus, which is essentially
A
mineralized dental biofilm.
19
Q
Dental caries is a disease of the
A
dental calcified structures (enamel, dentin, and cementum) characterized by demineralization of the mineral components and dissolution of the organic matrix.
20
Q
The sequence of events leading to demineralization and dental caries is
A
Cariogenic foodstuff leads to fermentable carbohydrates taken into biofilm
Ph of biofilm drops as the bacteria consume the carbohydrates
Acid is formed
Frequent exposure of tooth surface to acid leads to demineralization
Demineralization appears as a white lesion and is the start of caries
Eventually cavitated lesion develops
21
Q
Describe the microbiome of when a patient presents with caries
A
reduced diversity of microorganisms in microbiome to favor caries initiation.
Acid tolerant or acidogenic bacteria like S. mutans and S. sobrinus, and lactobacilli may be present. Possibly in some cases Actinomyces
22
Q
Explain the ph of biofilm
A
Critical pH for enamel demineralization averages 5.5.
The critical pH for root surface demineralization may be higher because of the lower mineral content of dentin and cementum.
The critical pH for demineralization of dentin is approximately 6.7, which is particularly relevant for patients with multiple areas of recession and xerostomia.
23
Q
What are the effects of diet on biofilm?
A
In a diet high in fermentable carbohydrates and cariogenic foods, biofilm
communities shift to bacteria with higher pH-lowering ability.
24
Q
What is materia alba?
A
a soft, whitish tooth deposit that is unorganized accumulation of living and dead bacteria, desquamated epithelial cells, disintegrating leukocytes, salivary proteins, and food debris. It is clinically visible without application of a disclosing agent. It may have a cottage cheese-like texture and appearance.
25
Prevention of Materia alba
can be removed with the basic mechanical oral self-care
procedures.
26
After food consumption, food remnants may collect in areas of the cervical third and proximal embrasures of the teeth.
Food Debris
27
____ results during mastication as food is forced into open contact areas (loss of proximal contact), dental diastemas, poorly contoured restorations, or occlusal irregularities such as plunger cusps.
Vertical food impaction
28
Left unattended, the accumulation of ____adds to a general unsanitary condition of the mouth and may contribute to the initiation of dental caries and oral malodor.
food debris
29
Dental calculus is
dental biofilm mineralized by crystals of calcium phosphate mineral salts between previously living microorganisms that forms on the clinical crowns of natural teeth, dental implants, dentures, and other dental prostheses.
30
Calculus is covered with a layer of____
nonmineralized dental biofilm containing live bacteria
31
Dental calculus is classified by its location on a tooth surface as related to the adjacent free gingival margin, that is_______
supragingival and subgingival calculus
32
This type of calculus forms on clinical crowns coronal to the margin of the gingiva, implants, complete and partial dentures.
Supragingival calculus
33
Where are the most frequent sites of supragingival calculus?
On the lingual surfaces of mandibular anterior teeth and the facial surfaces of maxillary first and second molars
On the crowns of teeth out of occlusion, nonfunctioning teeth, or teeth that are neglected during daily biofilm removal (toothbrushing or interdental care).
On surfaces of dentures, dental prostheses, and oral piercings.
34
Calculus that forms apical to the margin of the gingiva and extending toward the clinical attachment on the root surface.
Forms on dental implants.
Subgingival calculus
35
Where are the most frequent sights of subgingival calculus?
The calculus typically will form at the cementoenamel junction as recession and pocket formation continue. May be generalized or localized and heaviest in areas most difficult for the patient to access during personal oral biofilm removal procedures.
36
The color of subgingival calculus comes from exposure to the
products of blood, blood breakdown products and also bacteria formed in calculus can contribute to the pigment
37
Calculus is composed of
inorganic and organic components and water.
38
How does calculus form?
Dead microorganisms breakdown and the initial calcium phosphate crystals (typically brushite) of calculus start to form by binding with the phospholipids in the cell walls (cell membrane) of bacteria. Eventually mineralization of calculus will progress to include the other types of calcium phosphate crystals octacalcium phosphate, whitlockite, and finally to a stable hydroxyapatite phase that occurs around 8 months after initial formation.
39
What are the factors in rate of calculus formation?
Genetic and individual variation in saliva composition and flow.
Diet
Individual variations in bacterial load.
Age, race, and gender.
More severe periodontal disease.
Malposition and crowding of teeth.
Lower levels of S. mutans.
Presence of inhibitors of calculus formation
40
Types of Calculus Deposits
• Crusty, spiny, or nodular deposits.
• Ledge or ring formation.
• Thin, smooth veneers.
• Finger- and fern-like formations.
• Individual calculus islands or spots.
41
How does calculus attach to a tooth?
1.by Means of an Acquired Pellicle
2. to Minute Irregularities in the Tooth Surface
3. by Direct Contact with the Tooth Surface
by interlocking of inorganic apatite crystals of the enamel and cementum with the calcium phosphate crystals of the calculus.
42
The extent of demineralization of a tooth depends on what factors?
the length of time and frequency the pH is below critical level, biofilm composition, pH-lowering ability of the microorganisms, and action of saliva
43
Dental calculus contains what four types of calcium phosphate crystals?
• Brushite
• Octocalcium phosphate
• Hydroxyapatitie
• Whitlockite
44
The formation time of calculus depends on
individual factors like homecare
45
What is the color of supragingival calculus?
White, creamy yellow, or gray. May be stained by tobacco, food, tea, or coffee
Slight deposits may be invisible until dried with compressed air
46
What is the color of subgingival calculus?
Light to dark brown, dark green, or black due to gingival crevicular fluid, blood and blood breakdown products
47
What is the shape of supragingival calculus?
Amorphous, bulky
Gross deposits may:
• Form interproximal bridge between adjacent teeth.
• Extend over the margin of the gingiva
• Form based on the anatomy of the teeth; contour of gingival margin; and pressure of the tongue, lips, cheeks
48
What is the shape of subgingival calculus?
Conforms to the root surface due to constraints of the pocket wall
Calculus formations occur in the following forms:
• Crusty, spiny, or nodular
• Ledge or ringlike
• Thin, smooth veneers
• Finger- and fern-like
• Individual calculus islands
49
What is the distribution of calculus on an individual tooth supragingivally?
Coronal to margin of gingiva
50
What is the distribution of calculus on an individual tooth subgingivally?
Apical to margin of gingiva
Extends to bottom of the pocket and follows contour of soft-tissue attachment
51
What is the distribution of calculus on
teeth supragingivally?
Symmetrical arrangement on teeth, except when influenced by:
• Malpositioned teeth
• Unilateral hypofunction
• Inconsistent personal oral self-care
Location related to openings of the salivary gland ducts
52
What is the distribution of calculus on
teeth subgingivally?
Heaviest on proximal surfaces, lightest on facial surfaces
Occurs with or without associated supragingival deposits
53
How do we do a supragingival examination for calculus?
A. Direct Examination (use mouth mirror for indirect)
B. Use of Compressed Air and light for invisible deposits
54
How do we do a subgingival examination for calculus?
A. Visual Examination: (Dark edges of calculus may be seen at or just beneath the gingival margin.
B. Gingival Tissue Color Change for dark calculus
C. Tactile Examination
D. Radiographic Examination
E. The use of a dental endoscope
55
Risk factors related to calculus formation are similar to those for dental biofilm formation and relate to the patient's___
daily biofilm removal regime
56
A patients regular removal of dental biofilm by _____is a major factor in the control of dental calculus reformation.
appropriately selected brushing, interdental care, and supplementary methods
57
How is calculus prevented?
Patient oral hygiene/ oral self-care, regular profession continuing care, and anticalculus dentifrice
58
Discolorations of the teeth and restorations occur in three general ways:
• Adhered directly to the tooth surfaces.
• Contained within calculus or pellicle.
• Incorporated within the tooth structure or the restorative material.
59
What are stains classified by location?
Extrinsic or intrinsic
60
What is an Extrinsic stain?
Stains that occur on the external surface of the tooth and may be removed by procedures of toothbrushing, scaling, and/or polishing.
61
What is an intrinsic stain?
Stains that occur inside of tooth structure due to changes in structural composition or thickness of the enamel. Occurs in development defects and acquired defects like restorative materials.
62
What is internalized discoloration?
When extrinsic stain is internalized into the tooth structure following development.
63
What are stains classified by source?
Exogenous and endogenous
64
What is an Exogenous stain?
Develops or originates from sources outside the tooth.
65
Exogenous stains may be either ____
extrinsic and stay on the outer surface of the tooth or intrinsic and become incorporated within the tooth structure.
66
What is an Endogenous stain?
Develops or originates from within the tooth
67
Endogenous stains are always___
intrinsic and usually are discolorations of the dentin reflected through the enamel.
68
What could help in recognition and identification of cause of dental stains?
Medical, psychosocial and dental history, assessment of patient’s food diary, and patient’s oral hygiene habits
69
What are the different types of extrinsic stains?
Yellow stain, green stain , black-line stain, tobacco stain, brown stain, orange and red stain, metallic stain
70
What kind of stain is this? Why and where does it occur?
Yellow exogenous extrinsic stain that is localized or generalized discoloration of dental biofilm and caused by either diet or use of tobacco. It typically occurs in adults and when oral self-care is bad.
71
What do green stains look like?
Light or yellowish green to very dark
green. Occurs in three general forms:
• Small curved line following contour of facial gingival margin.
• Irregular coverage of flat tooth surfaces.
• Streaked, following grooves or lines in enamel.
72
where do green stains occur? At what age?
Collects on both permanent and primary teeth. Most frequently facial gingival third of maxillary anterior teeth.
May occur at any age; primarily found in childhood.
73
What is the composition of green stains?
• Chromogenic bacteria.
• Decomposed hemoglobin.
• Inorganic elements include copper, nickel, and other elements in small amounts.
• Chromogenic bacteria are nourished in dental biofilm where the green stain is produced.
• Blood pigments from hemoglobin are
decomposed by bacteria.
74
Why does green stain occur?
poor oral hygiene causing dental biofilm, chromogenic bacteria, and gingival hemorrhage.
75
Most green stains can be removed by
with a toothbrush during oral self-care education and the least abrasive polishing agent for stain removal.
76
Other than poor oral hygiene, green stain of the acquired pellicle and dental biofilm can also be caused by
Chlorophyll preparations.
Metallic dust produced by some industries.
Green tea.
Certain drugs, such as smoking marijuana.
77
What does black line stain look like? Where is it found?
A black or dark brown continuous or interrupted fine (1 mm) or thick (in rare cases) line formed by pigmented spots along the gingival third near the gingival margin of facial and lingual surfaces into the proximal surfaces or at bases of pits and fissures of primary or permanent teeth.
78
Black line stains are most frequently where?
On the lingual and proximal surfaces of maxillary posterior teeth and occlusal pits.
79
Black-line stain is composed of
chromogenic microorganisms embedded in a ferric matrix with a higher phosphorus-calcium content. It has a lower amount of cariogenic microorganisms than biofilm
80
Attachment of black-line stain to the tooth is by a
pellicle-like structure.
81
At what ages does black line stains usually occur?
Occurrence increases with age
82
Black-line stain is______because it tends to form again despite regular personal care.
Recurrent
83
This may reduce the likelihood of recurrence of black line stain.
Quantity may be less when biofilm control procedures are meticulous.
84
What are the predisposing factors for black line stain?
• Actinomyces
• Dietary habits.
• poor oral hygiene.
• Iron supplements
85
What does tobacco stain look like?
Light brown to dark leathery brown or black; incorporated in calculus deposit.
86
In tobacco stain, heavy deposits (particularly from smokeless tobacco) may penetrate irregularities in the enamel and become___
exogenous intrinsic.
87
Where can tobacco stain be found?
Narrow band that follows contour of gingival crest, slightly above the crest. Incorporated in calculus deposits or diffused staining of dental biofilm.
OR
Wide, firm, tar-like band may cover the cervical third and extend to the central third of the crown, primarily on lingual surfaces.
88
What is the composition of tobacco stain?
• Tar and products of combustion.
• Brown pigment from smokeless tobacco.
89
What are the predisposing factors for tobacco stain?
Smoking or chewing tobacco or use of hookah to inhale tobacco. The quantity of stain is not necessarily proportional to the amount of tobacco used.
• Inadequate oral self-care.
• Extent of dental biofilm and calculus available for adherence.
90
What do brown stains look like? Where is it found?
Brown. Pellicle takes on colors from chemical alterations
91
Where is brown stain primarily found?
Found primarily on buccal of maxillary molars and lingual of mandibular anterior surfaces.
92
What are the predisposing factors for brown stain?
Poor oral hygiene
Tannins in tea, coffee, soy sauce, and other foods may also deposit in the pellicle, resulting in brown stain
93
What does brown stain caused by stannous flouride look like?
Light brown, sometimes yellowish, stain forms on the teeth in the pellicle.
94
What kind of antimicrobial agents may cause brown stain?
Chlorhexidine
95
What may cause brown stain caused by antimicrobial agents? And what does it look like?
Chromogenic polyphenols in the diet such as coffee, tea, and wine may interact with chlorhexidine and worsen the staining.
A brownish stain on the tongue and tooth surfaces may result, usually more pronounced on proximal and other surfaces less accessible to routine biofilm control procedures. The stain also tends to form more rapidly on exposed roots than on enamel.
96
Stain caused by chlorhexidine may not be removable from enamel defects, anterior composite, and crown- or veneer-type restorations. Therefore, when suggesting this product for treatment___
careful consideration of risk versus benefit of use as an antimicrobial agent is needed by the patient and clinician.
97
What does brown stain caused by betel nut look like?
The discoloration imparted to the teeth is a dark mahogany brown, sometimes almost black. It may become thick and hard, with partly smooth and partly rough surfaces.
98
Microscopically, the black deposit of betel nut caused brown stain consists of
microorganisms and mineralized material with a laminated pattern characteristic of subgingival calculus.
99
What does “swimmer’s stain” brown stain look like and caused by?
Frequent exposure to pools disinfected with chlorine or bromine can cause yellowish or dark brown stains on the facial surfaces of maxillary and mandibular incisor teeth.
100
What kind of stain is this?
Tobacco stain
101
What type of stain is this?
Brown stain
102
What do red and orange stains look like? Where do they occur?
Orange or red (rarer than orange) stains appear at the cervical third. More frequently on anterior than on posterior teeth.
103
What caused orange and red stains?
Possibly chromogenic bacteria.
Poor oral hygiene
104
Where is metallic stain usually found?
Primarily anterior; may occur on any teeth.
Cervical third more commonly affected
105
How does metallic stain form?
Industrial workers inhale dust through the mouth, bringing aerosolized metallic particles in contact with teeth.
Metal imparts color to pellicle.
Occasionally, stain may penetrate tooth surface and become exogenous intrinsic stain.
106
How is metallic stain prevented?
Workers need to be advised to wear a mask while working.
107
Endogenous intrinsic stains may be caused by
Pulpless or traumatized teeth, distrubances in tooth development, drug-induced
108
Pulpless or traumatized teeth may cause to to have what color? What is the cause?
light yellow-brown, slate gray, reddish-brown, dark brown, bluish-black, or black. Others have an orange or greenish tinge.
Blood and other pulp tissue elements may be available for breakdown as a result of hemorrhages in the pulp chamber, root canal treatment, or necrosis and decomposition of the pulp tissue.
• Pigments from the decomposed hemoglobin and pulp tissue penetrate and discolor the dentinal tubules.
109
Give some examples of disturbances in tooth development that may influence staining?
Amelogenesis imperfecta, Dentinogenesis imperfecta, enamel hypoplasia, enamel opacity, molar-incisor hypomineralization (MIH), and dental fluorosis
110
What is Amelogenesis imperfecta and what stains does it cause?
The enamel is partially or completely missing due to a generalized disturbance of the ameloblasts. Teeth are yellow to yellowish-brown.
111
What is Dentinogenesis imperfecta and what stains does it cause?
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 yellow-brown to blue-gray.
112
Both Amelogenesis imperfecta and Dentinogenesis imperfecta are ______ tooth development disturbances.
Genetic
113
Development enamel defects (DDE) like enamel hypoplasia, enamel opacity, and molar-incisor" hypomineralization (MIH) result from.
damage to the tooth germ during development
114
Generalized hypoplasia may extend across multiple teeth and color may vary from____.
chalky white to yellow or brown
115
Local hypoplasia affects a single tooth and color may look like___.
individual white spots
116
What is the general clinical appearance of DDEs?
Teeth erupt with white spots, pits, or grooves depending on the severity of the injury to the tooth germ.
Over time, the enamel hypoplasia defects are prone to extrinsic stain.
117
What is the color of stain caused by fluorosis?
When the teeth erupt, the color of the enamel ranges from chalky white spots to brown.
Severe effects of excess fluoride during development may produce cracks or pitting. This condition and appearance led to the name mottled enamel.
118
Give two examples of drug induced stains.
Tetracycline and minocycline
119
Tetracycline antibiotics have an affinity for calcium and form complexes with____
hydroxyapatite crystals in mineralized tissues
120
Discoloration of a child's teeth may result when tetracycline is administered to
the mother during the fourth month of pregnancy or to the child in infancy and early childhood.
121
What does tetracycline staining look like? Where would it be found?
Discoloration may be generalized or localized to individual teeth that were developing at the time of administration of the antibiotic.
Color of teeth may be light green to dark yellow, or a gray-brown
122
Unlike tetracycline, minocycline has been reported to cause ___
generalized intrinsic staining posteruption.
123
Use of minocycline can result in a
generalized intrinsic blue-gray to gray staining of the permanent teeth.
124
When intrinsic stains come from an outside source, not from within the tooth, the stain is called____
exogenous intrinsic.
125
When extrinsic stains penetrate enamel defects and exposed dentin, they can become ____. These may also be called internalized discoloration.
Instrinsic
126
Most likely from an outside source such as tobacco or food and becomes intrinsic over time.
Exogenous instrinsic stain
127
The sources of these exogenous instrinsic may include:
Diet
Tobacco use
• Developmental defects.
• Acquired defects such as tooth wear and gingival recession.
• Dental caries.
• Restorative materials
128
Silver amalgam can impart ______causing a exogenous intrinsic stain.
a gray to black discoloration to the tooth structure around a restoration
129
How does silver amalgam cause exogenous intrinsic stain?
Tin migrates from the amalgam restoration into the enamel and dentin.
130
Discoloration caused by endodontic therapy can cause exogenous intrinsic stains that tends to be most evident on the ___of teeth.
cervical third of the crown and root surface
131
Materials used during endodontic therapy can cause____ staining.
Exogenous intrinsic
132
Endodontic sealers may cause stain ranging in color from
orange-red to gray
133
Endodontic medicaments, which may include tetracycline, may cause a____ intrinsic stain.
dark brown
134
Portland cement-based materials of endodontic therapy may cause a___ intrinsic stain.
gray
135
Antibiotic pastes used in regenerative endodontic procedures may also contain tetracycline, but also ciprofloxacin, metronidazole, or minocycline, and result in a___ staining.
green-brown
136
A discoloration resulting from a carious lesion that causes stain in dentin is an example of a____stain.
Exogenous intrinsic
137
Arrested decay or secondary dentin can present as____ on severely decayed teeth. The surface is hard and glossy, and stain cannot be removed.
black stain
138
Enamel erosion and Attrition of occlusal surfaces can result in thinner enamel which allows_____
the yellow color of the underlying dentin to show through and cause the teeth to appear duller gray or yellow or brown.
