Introduction and Etymology of Calculus
- The word 'calculus' comes from Latin, meaning 'small stone' or 'limestone.'
- The term 'calculus' was used for various kinds of stones.
- The word 'calculate' is derived from 'calculus,' referring to the use of stones for mathematical purposes.
- 'Calculus' in the 18th century came to be used for mineral buildups in human and animal bodies, such as kidney stones and minerals on teeth.
- 'Tartar' originates from Greek as the term for the white encrustation inside casks.

Composition and Formation of Calculus
- The organic component of calculus is approximately 85% cellular and 15% extracellular matrix.
- Calculus contains primarily bacterial cells, including species of archaea and yeast.
- The organic extracellular matrix in calculus consists of proteins, lipids, and extracellular DNA.
- Trace amounts of host, dietary, and environmental microdebris are also found within calculus.
- These microdebris include salivary proteins, plant DNA, milk proteins, starch granules, textile fibers, and smoke particles.
- Supragingival calculus forms on the buccal surfaces of upper molars and lingual surfaces of lower incisors.
- Subgingival calculus forms below the gumline and is typically darkened in color by black-pigmented bacteria.
- Dental calculus forms in incremental layers, visible through electron microscopy and light microscopy.
- The timing and triggers of calculus formation events are poorly understood.
- Various factors influence the formation of dental calculus, including age, gender, diet, oral hygiene, bacterial plaque composition, and systemic diseases.

Clinical Significance of Calculus
- Calculus accumulation causes gingivitis and periodontitis.
- Calculus serves as a trap for increased plaque formation and retention.
- Supragingival plaque contains aerobic bacteria and yeast, while subgingival plaque contains anaerobic bacteria.
- Anaerobic plaque bacteria trigger inflammation in the periodontium, leading to bone loss and weakening of gingival fibers.
- Almost all individuals with periodontitis exhibit considerable subgingival calculus deposits.

Prevention and Removal of Calculus
- Toothpaste with pyrophosphates or zinc citrate can reduce plaque accumulation.
- Some calculus may form without plaque deposits through direct mineralization of the pellicle.
- Regular brushing and flossing can help prevent calculus formation.
- Regular dental check-ups and professional cleanings can remove calculus buildup.
- Maintaining good oral hygiene practices is essential for preventing calculus formation.
- Plaque and calculus deposits are major contributors to oral disease.
- Dental hygienists use specially designed instruments to remove plaque and calculus deposits.
- Calculus deposits cannot be removed by brushing or flossing alone.
- The frequency of dental hygiene treatment depends on individual patient needs.
- Hand instruments like scalers, curettes, jaquettes, hoes, files, and chisels are used for calculus removal.
- Ultrasonic scalers are effective in removing calculus, stain, and plaque.
- There are two types of ultrasonic scalers: piezoelectric and magnetostrictive.
- Special tips for ultrasonic scalers are designed for different areas of the mouth and amounts of calculus buildup.
- Heat is generated at the tip of the scaler, so a water spray is used to cool it during debridement.
- Small adaptations are necessary to keep the tip of the scaler in contact with the tooth surface.
- Near-ultraviolet and near-infrared lasers are being researched for more effective calculus removal.
- Lasers offer advantages over conventional hand instrumentation for accessing periodontal pockets.
- Near-infrared lasers, like the Er,Cr:YSGG laser, are effective for root scaling due to their absorption by water.
- Near-ultraviolet lasers allow for quick calculus removal without removing healthy tooth structure.
- Dental hygienists require additional training on laser use where permitted by legislation.

Miscellaneous Information
- Dental calculus is a hard deposit that forms on teeth.
- It is composed of inorganic mineralised substances such as calcium phosphate and calcium carbonate.
- Calculus formation is influenced by factors like oral hygiene, diet, and saliva composition.
- Bacteria in dental plaque play a crucial role in calculus formation.
- Calculus can accumulate both above and below the gumline.
- Calculus can lead to gum inflammation and periodontal disease.
- It provides a rough surface for plaque bacteria to adhere to, making oral hygiene more challenging.
- Calculus buildup can cause bad breath (halitosis).
- It can contribute to tooth decay and cavities.
- Dental calculus can also harbor harmful bacteria that may contribute to systemic health issues.
- Dental calculus can preserve a wealth of biological data from ancient populations.
- Microbial analysis of ancient dental calculus provides insights into the oral microbiome of past populations.
- Studies have identified ancient pathogens and evidence of dietary habits through dental calculus analysis.
- Ancient dental calculus has revealed the consumption of plants, milk, and even evidence of medicinal plant use.
- Dental calculus analysis has also shed light on the oral health and hygiene practices of ancient populations.
- Dental calculus analysis is not limited to human studies; it has been used in animal studies as well.
- Studies have examined the oral health and diet of domestic pets through dental calculus analysis.
- Dental calculus analysis in chimpanzees has provided insights into their plant consumption and life history transitions.
- Ancient DNA analysis of dental calculus has revealed information about Neanderthal behavior, diet, and disease.
- Dental calculus analysis has also been used to study changes in oral microbiota with dietary shifts in different time periods.