Periodontics › Aetiology
Dental Calculus
High-yield revision notes with linked practice questions, written for dental students and candidates preparing for the ADC and other licensing examinations.
High-yield notes
Mineralization inhibitors of calculus formation include all of following except disphosphates
Sub-gingival tooth associated plaque causes caries
Sub-gingival tissue associated plaque causes periodontal destruction
Calculus is not an irritating factor but a contributing factor to periodontitis
Rate of plaque form is almost same on both crown and root
Calculus causing bacteria is Veillonella
The consistency of sub-gingival calculus is described to be Flint like
The consistency of supragingival calculus is Clay like
Crystalline form of calcium phosphate found in higher concentration in supra-gingival plaque is Hydroxyapatite and Octacalcium phosphate
Brushite crystal forms of calculus are more common in Mandibular anterior
Subgingival calculus, as compared to supragingival calculus are Denser
Mineral critical for calculus formation is phosphate ion.
Microorganisms are not always necessary for calculus formation
Plaque has the ability to concentrate calcium 2-20 times its level in saliva.
Mature plaque has-
- Outer (Spirochetes, Gram-ve rods)
- Tooth surface (Gram +ve cocci and short rods)
Pellicle (first formed layer,prerequisite of plaque) is salivary glycoprotein without bacteria
After toothbrushing
- Within seconds: Acquired pellicle formation,bacterial adhesion
- 2 hours: Initial plaque formation, Irreversible bacterial colonization
- 6 hours: Supragingival plaque well established
- 2 days: Plaque doubles in mass, 50% mineralized
- 5-7 day: Plaque maturation dominated by filamentous bacteria
- 21 days:
- Bacteria replication slows
- Maximal accumulation of plaque
- Plaque accumulation becomes relatively stable
- 12 weeks: Subgingival plaque formation (well-differentiated)
Practice questions
Select an option to check your answer. Answers are shown below each question.
In periodontal disease, calculus is considered as
- Acontributing factor b. primary factor
- BAetiological factor d. Governing factor
- Ctriclosan b. Pyrophosphate
- DZinc salt d. Diphosphate
Inorganic content of calculus has maximum of
- ACaPO4 b. CaCl2
- BCaSO4 d. CaCO3
- CLower anterior region b. Lower bicuspid region
- DLower molar region d. Upper molar region
Subgingival calculus is usually
- AFound as a bridge like structure over the interdental papilla of the adjacent teeth
- BHard with a clay like consistency, easily detached from the tooth surface
- CHard and dense and firmly attached to the tooth surface
- DDerived for saliva
These notes are compiled from standard periodontology texts for study purposes. They are a revision aid, not a substitute for your own reading or current clinical guidelines. If you spot an error, please leave a comment.