Dental calculus Flashcards
what is dental calculus?
- mineralized biofilm
- hard tenacious mass that forms on crowns of teeth, roots and any dental prothesis
- calculus is significant in the progression of inflammation and periodontal disease because it provides a rough surface for the adherent bacterial biofilm to attach to
does calculus cause disease?
NO - biofilm causes disease. thus, it is important for the clinician to:
- thoroughly remove calculus deposits from the tooth surface (rough surface)
- educated the patient on the importance of thorough home cleaning on a daily basis and regular dental cleanings
how is dental calculus classified? what are the 2 types of dental calculus?
- by its location on the tooth surface related to the adjacent free gingival margin
- supragingival calculus and subgingival calculus
when and where can a patient get calculus?
- at any age, on any permanent or primary tooth
- increases with age
- more likely to be seen on secondary teeth
how does supragingival calculs appear?
- cream, chalky, can be stained by extrinsic stains (yellow, black, brown)
where is subgingival calculus located?
most commonly interproximally
- can form in any sulcus
- tends to follow supragingival calculus
how does subgingival calculus attach/what to?
- most mechanical by interlocking within dentin/cementum (difficult to remove)
- can attach through acquired pellicle (will be weak)
identification of calculus prior to removal depends on:
appearance, consistency and distribution
appointment planning, instrument selection, and technique used for removal depends on the understanding of:
- texture, morphology and mode of attachment of the calculus deposit
how can we examine supragingivally for calculus?
- direct examination using a mouth mirror
- use of compressed air (small deposits are more noticeable when dry)
how can we examine subgingivally for calculus?
- visual examination: dark edge or hue can be seen below the gingival margin, use compressed air, and transillumination to view dark dull shadow areas
- gingival tissue colour change: dark calculus shine through thin gingiva
- tactile examination: probe and explore to asses location and amount
- radiographs: can exhibit large deposits interproximally
- perioscopy: can show calculus in deep pockets and furcations that go otherwise undetected (burnished)
how do we describe the calculus deposits on a patient’s clinical record?
- calculus deposits must be described in the clinical examination record
- the location (sub/supra) and the extend of the deposit (mild/moderate/severe) must be designated
- description: granular, spicules and ledges, tenacity
calculus formation step-by-step
1 - pellicle formation
2 - biofilm maturation*
3 - mineralization*
what are the steps to biofilm maturation?
1 - microorganisms settle in the pellicle layer
2 - colonies are formed
3 - the colonies grow together to form a cohesive biofilm layer
what is mineralization?
within 24-72 hours, more and more mineralization centers develop close to the underlying tooth surface. eventually the centers grow large enough to touch and unite
mineralization formation depends on…
- roughness of tooth surface
- oral hygiene
- quantity of biofilm
- salivary flow
- saliva/oral cavity pH
- light formers: pyrophosphate in saliva
what is the average formation time for dental calculus?
- about 12 days for soft biofilm to mineralize into dental calculus (ranges from 10 days for quick formation to 20 days for slow formation)
- mineralization can begin as early as 24-72 hours
structures of calculus: layers
- forms in layers that are parallel to the tooth surface
- these layers are separated by a line of pellicle that was deposited over the previously formed calculus
- incremental lines
- this is evidence that calculus grows or increases by apposition of new layers
structure of calculus: surface
- the surface of a calculus deposit is rough and appears as peaks, valleys and pits
structure of calculus: outer layer
- the outer layer of a subgingival deposit is partly calcified
- on the surface is a soft mat-like layer of dental biofilm
- this outer surface of biofilm is in contact with epithelial tissue in the pocket increasing disease potential
3 modes of attachment for dental calculus:
1 - acquired pellicle: is superficial because no interlocking or penetration
2 - mechanical: attachment to minute irregularities in the tooth surface by mechanical locking into undercuts
3 - direct contact: interlocking of inorganic crystals or tooth with mineralizing dental biofilm
composition of calculus: inorganic
- inorganic components, mainly calcium, phosphorus, CO3, sodium, magnesium, and potassium
- trace elements: including Cl, Zn, Sr, Br, Cu, Mn, Au, Al, Si, Fe, and Fl
- fluoride
- crystals: principally apatite
calculus compared with teeth:
- enamel is the most highly calcified tissue in the body: 96% inorganic
- calculus is 75-85% inorganic
composition of calculus: organic
consists of:
- various types of non-vital microorganisms
- desquamated epithelial cells
- leukocytes
most of the organisms in calculus are nonviable
its the biofilm on the surface that contains the viable organisms
how does subgingival biofilm develop? what does it contain?
- subgingival biofilm develops as a result of downward growth of supra-gingival biofilm bacteria
- subgingival biofilm contains pathogenic bacteria that cause inflammation and destruction in the gingival tissue
relationship of dental calculus attachment loss and pocket formation:
- with increased pocket depth, greater amounts of biofilm can accumulate with increased numbers of pathogenic organisms
- calculus is mineralized bacterial biofilm that forms next to the tooth surface
- subgingival calculus is always covered by masses of active bacterial biofilm
- calculus can act as a reservoir for endotoxins and tissue breakdown products
- calculus is a predisposing factor in pocket development
professional removal of calculus:
- removal of calculus provides a smooth tooth surface in an environment conducive to gingival healing
- the smooth surfaces can be easier for the patient to maintain
- with emphasis on good oral hygiene and routine professional removal, low levels of supra and sub-gingival calculus have been demonstrated on a long-term basis
how can we prevent calculus?
- professional removal of calculus
- personal bacterial biofilm control
- anticalculus dentrifice/mouthrinses
what is personal bacterial biofilm control?
- removal of bacterial biofilm by appropriately selected brushing, flossing and supplementary methods is a major factor in the control of dental calculus re-formation
what is anticalculus dentrifice/mouthrinses?
- calculus control dentrifices/mouthrinses currently available contain pyrophosphates, zinc citrate, zinc chloride, or triclosan
- the dentrifices/rinses do not have an effect on existing calculus deposits and are offered as a preventive measure
