mineralized dental biofilm that is filled with crystals of various calcium phosphates; covered with a layer of nonmineralized dental biofilm containing viable active bacteria; and forms on the clinical crowns of natural teeeth and dental implants, dentures, and other dental prostheses
calculus
How is dental calculus classified?
by its location on a tooth surface as related to the adjacent free gingival margin
What are the two locations of calculus?
supragingival
subgingival
calculus found on the clinical crown coronal to the margin of the gingiva, also found on implants, complete and partial dentures
supragingival calculus
What are the number one most frequent sites of supragingival calculus? why?
lingual surface of mandibular anteriors
facial surfaces of maxillary first and second molars
they are opposite the openings of the ducts of the salivary glands
What are the number 2 most frequent site form supragingival calculus?
on the crowns of teeth out of occlusion
nonfunctioning teeth
teeth that are neglected during dayily biofilm removal
What are the mumber 3 most frequent sites of supragingival calculus?
on surfaces of dentures, prostheses, and tongue piercings
What are 4 other names for supragingival calculus?
supramarginal
extragingival
coronal
salivary
What type of calculus is found on the clinical crown apical to the margin of the gingiva and extending nearly to the clinical attachment on the root surface?
subgingival calculus
can subgingival calculus be found on dental implants?
yes
what is the most common place for subgingival calculus?
areas that are most difficult for the patient to access during personal biofilm removal
it can be generalized or localized
What are 2 other names for subgingival calculus?
submarginal
serumal
What are the 6 main inorganic components in calculus?
calcium
phosphorus
carbonate
sodium
magnesium
potassium
true or false. Fluoride is an inorganic component found in calculus sometimes
true
2/3 of the inorganic matter of calculus is ________, principally ________
crystalline
apatite (hydroxyapatite)
What are 3 other crystals besides apatite found in calculus?
brushite
whitlockite
octocalcium phosphate
What percent of each of the following substances is made up of mineralized inorganic salts:
enamel
dentin
cementum
mature calculus
96%
65%
45-50%
70-90%
nonvital microorganisms, desquamated epithelial cells, leukocytes, and mucin from saliva make up what proportion of calculus?
the organic content
cholesterol, cholesterol esters, phospholipids, and fatty acids in the lipid fraction; reduce sugars and carbonhydrate - protein complexes in the carbohydrate fractoin; and keratins, nucleoproteins, and amino acids in the protein portion are substances identified in what part of the calculus?
found in the organic matrix
What are the 3 basic steps that calculus formation occurs in?
pellicle formation
biofilm formation
biofilm mineralization
What is composed of mucoproteins from the saliva, is an acellular material, and begins to form within minutes after all deposits have been removed from the tooth surface?
pellicle or cuticle
In what step of calculus formation do microorganisms settle in the pellicle layer, colonies form consisting primarily of cocci and rod-shaped organisms in early calc, and the colonies grow together to form a cohesive layer
biofilm maturation
When is biofilm mostly made up of filamentous organisms?
by the 5th day
In what step of calc formation do the foci coalesce forming mineralized foci; mineralization first occurs in the intermicrobial matrix provided by the filamentous microorganisms; and as the deposit ages, mineralization within the bodies of bacteria occurs
mineralization of biofilm
What is the source of elements for supragingival calculus?
saliva
What is the source of elements for subgingival calculus?
gingival sulcus fluid and inflammatory exudate
What 3 places in order from first to last does crystal form in calculus?
in the intercellular matrix
on the surface of the bacteria
within the bacteria
What are the 4 types of crystals that form in mineralization of calculus?
hydroxyapatite
octocalcium phosphate
whitlockite
brushite
true or false. The mineralization process is considered the same for sub and supragingival calculus?
true
Heavy calculus formers have higher salivary levels of what 2 substances than do light calculus formers?
calcium and phosphorus
light calculus formers have higher levels of what substance?
parotid pyrophosphate
calculus forms in ________ that are more or less _________ with the tooth surface
layers
parallel
Layers in calculus are separated by a line that appears to be a pellicle that was deposited over the previously formed calc, and as mineralization progressed, the pellicle became emebedded.
incremental lines
How do incremental lines of calculus form in suptragingival calc?
around the tooth
How do incremental lines of calculus form in subgingival calculus?
they form irregularly from crown to apex on the root surface
incremental lines are evidence that calculus grows or increases by ________ of new layers
apposition
What does the surface of calculus feel like? And how is it detected?
rough
by use of an explorer
What layer of calculus is partly calcified, is a thick, matlike, soft layer of dental biofilm; and the subgingival calc is in contact with the disease pocket epithelium on this layer
outer layer
the average number of days required for the primary soft deposit to change to the mature mineralized stage
formation time
What is the average formation time for calculus? What is the range of formation time of calculus? and how early can mineralization begin when a patient's daily oral hygiene is neglected?
12 days
10 days for rapid formers-20 days for slow formers