Dental products: Calcium carbonate MCQs With Answer are essential study material for B. Pharm students learning excipient roles in oral care formulations. This concise, keyword-rich introduction covers calcium carbonate chemistry, grades used in dentifrices, abrasive properties, compatibility with fluoride, and quality control tests relevant to dental products. You will review precipitated vs ground calcium carbonate, particle size effects on relative dentin abrasivity (RDA), formulation tips for toothpastes and polishing pastes, and regulatory standards for pharmaceutical-grade calcium carbonate. The questions focus on formulation science, analytical assays, stability, and safety considerations to build practical competence. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What is the chemical formula of calcium carbonate commonly used in dental products?
- CaO
- CaCO3
- Ca(OH)2
- CaCl2
Correct Answer: CaCO3
Q2. Which grade of calcium carbonate is typically preferred for smoother texture in toothpaste formulations?
- Ground calcium carbonate (GCC)
- Precipitated calcium carbonate (PCC)
- Calcined calcium carbonate
- Hydrated calcium carbonate
Correct Answer: Precipitated calcium carbonate (PCC)
Q3. Calcium carbonate acts primarily as which functional excipient in dentifrices?
- Preservative
- Abrasive and bulking agent
- Humectant
- Flavoring agent
Correct Answer: Abrasive and bulking agent
Q4. Which analytical technique is commonly used to determine particle size distribution of calcium carbonate for dental use?
- UV-Vis spectroscopy
- Laser diffraction
- Colorimetry
- Paper chromatography
Correct Answer: Laser diffraction
Q5. How does decreasing particle size of calcium carbonate affect abrasivity in toothpaste?
- Smaller particles generally increase abrasivity
- Smaller particles generally decrease abrasivity
- Particle size has no effect on abrasivity
- Smaller particles cause chemical corrosion, not abrasivity
Correct Answer: Smaller particles generally decrease abrasivity
Q6. Which reaction describes calcium carbonate reacting with hydrochloric acid during identity tests?
- CaCO3 + 2HCl → CaCl2 + CO2 + H2O
- CaCO3 + H2O → Ca(OH)2 + CO2
- CaCO3 + NaOH → Na2CO3 + Ca(OH)2
- CaCO3 → CaO + CO
Correct Answer: CaCO3 + 2HCl → CaCl2 + CO2 + H2O
Q7. Why is calcium carbonate sometimes incompatible with sodium fluoride in toothpaste?
- It forms insoluble calcium fluoride, reducing available fluoride
- It causes excessive foaming with fluoride
- It reacts to produce strong acids
- It oxidizes fluoride to fluorine gas
Correct Answer: It forms insoluble calcium fluoride, reducing available fluoride
Q8. Which fluoride source is more compatible with calcium carbonate-containing toothpastes?
- Sodium fluoride (NaF)
- Stannous fluoride (SnF2)
- Sodium monofluorophosphate (MFP)
- Hydrofluoric acid
Correct Answer: Sodium monofluorophosphate (MFP)
Q9. What is the approximate molar mass of calcium carbonate (CaCO3)?
- 56 g/mol
- 100 g/mol
- 198 g/mol
- 74 g/mol
Correct Answer: 100 g/mol
Q10. Which quality test assesses the carbonate content by measuring loss on ignition for calcium carbonate?
- Loss on drying
- Loss on ignition (LOI)
- Viscosity measurement
- Turbidity test
Correct Answer: Loss on ignition (LOI)
Q11. In dental polishing pastes, calcium carbonate contributes to which therapeutic or cosmetic benefit?
- Antibacterial activity
- Mechanical removal of extrinsic stains
- Fluoride delivery
- Enamel remineralization via fluoride release
Correct Answer: Mechanical removal of extrinsic stains
Q12. Which parameter is critical to report for calcium carbonate used in dentifrices to predict abrasivity?
- Moisture content only
- Particle size distribution and shape
- Color only
- pH of solid powder
Correct Answer: Particle size distribution and shape
Q13. Which method is commonly used for assay of calcium carbonate in pharmaceutical samples?
- Gravimetric determination after conversion to CaO
- Titration with standardized acid (acidimetry)
- Gas chromatography
- Mass spectrometry
Correct Answer: Titration with standardized acid (acidimetry)
Q14. Which impurity limit is especially important for calcium carbonate intended for dental products?
- Heavy metals (lead, arsenic)
- Protein content
- Enzymatic activity
- Vitamin contamination
Correct Answer: Heavy metals (lead, arsenic)
Q15. Precipitated calcium carbonate (PCC) is produced by which general process?
- Thermal decomposition of limestone
- Precipitation from calcium hydroxide and carbon dioxide
- Electrolysis of calcium salts
- Biological fermentation
Correct Answer: Precipitation from calcium hydroxide and carbon dioxide
Q16. Which physical property of calcium carbonate most directly affects toothpaste stability and rheology?
- Color
- Specific surface area and particle morphology
- Boiling point
- Electrical conductivity
Correct Answer: Specific surface area and particle morphology
Q17. Which test measures abrasivity of a dentifrice formulation rather than the raw abrasive itself?
- Relative dentin abrasivity (RDA) test
- pH meter reading
- Weight loss on heating
- Microbial limit test
Correct Answer: Relative dentin abrasivity (RDA) test
Q18. Calcium carbonate is largely insoluble in water; it dissolves readily in which medium?
- Neutral water
- Acidic solutions
- Organic solvents like ethanol
- Alkaline solutions only
Correct Answer: Acidic solutions
Q19. Which property makes calcium carbonate a preferred bulking agent in some toothpastes?
- High solubility in saliva
- Low cost and good compressibility
- Strong antimicrobial action
- Ability to release fluoride
Correct Answer: Low cost and good compressibility
Q20. Which regulatory guideline should B. Pharm students consult for specifications of pharmaceutical-grade calcium carbonate?
- Food Safety and Standards only
- USP/NF or relevant pharmacopeial monographs
- Cosmetic ingredient listings only
- Plant protection manuals
Correct Answer: USP/NF or relevant pharmacopeial monographs
Q21. Which test can detect the presence of carbonate ion in a sample of calcium carbonate?
- Treatment with dilute acid producing effervescence (CO2)
- Flame test for sodium
- Reaction with iodine
- Color change with phenolphthalein in neutral solution
Correct Answer: Treatment with dilute acid producing effervescence (CO2)
Q22. Which form of calcium carbonate typically has a higher specific surface area suitable for polishing applications?
- Ground calcium carbonate (GCC)
- Precipitated calcium carbonate (PCC)
- Calcite-free calcium carbonate
- Hydrated limestone
Correct Answer: Precipitated calcium carbonate (PCC)
Q23. What effect does moisture uptake have on calcium carbonate in toothpaste formulations?
- Improves antimicrobial activity
- May alter rheology and promote microbial growth
- Makes it volatile
- Converts it to a soluble salt
Correct Answer: May alter rheology and promote microbial growth
Q24. Which instrumental method is suitable for identifying crystal polymorphs of calcium carbonate (e.g., calcite vs aragonite)?
- Infrared spectroscopy only
- X-ray powder diffraction (XRPD)
- Ultrafiltration
- High-performance liquid chromatography (HPLC)
Correct Answer: X-ray powder diffraction (XRPD)
Q25. Which safety concern is most relevant when handling fine calcium carbonate powders in manufacturing?
- Explosive gas evolution
- Respiratory irritation and dust inhalation
- Spontaneous combustion
- Radioactivity
Correct Answer: Respiratory irritation and dust inhalation
Q26. Which excipient property of calcium carbonate helps control toothpaste opacity and whiteness?
- High refractive index and light scattering
- Strong color imparting dyes
- High solubility that clears the paste
- Enzymatic action
Correct Answer: High refractive index and light scattering
Q27. In formulation, which ingredient must be optimized when using calcium carbonate to avoid phase separation?
- Flavors only
- Humectants and thickeners (e.g., glycerin, carbomers)
- Preservatives only
- Colorants
Correct Answer: Humectants and thickeners (e.g., glycerin, carbomers)
Q28. What is one reason manufacturers might choose calcium carbonate over silica as an abrasive?
- Calcium carbonate is more chemically reactive with fluoride
- Calcium carbonate is often less expensive and gives milder abrasivity
- Calcium carbonate always provides whitening via chemical bleaching
- Calcium carbonate is soluble in ethanol
Correct Answer: Calcium carbonate is often less expensive and gives milder abrasivity
Q29. Which stability issue should be monitored in calcium carbonate-containing dental gels?
- Hydrolysis producing alcohols
- Settling of abrasive particles and rheology changes
- Spontaneous polymerization
- Formation of peroxides
Correct Answer: Settling of abrasive particles and rheology changes
Q30. Which packaging consideration is important for calcium carbonate-based dentifrices?
- Transparent packaging to allow light-induced reactions
- Moisture-proof packaging to prevent water uptake
- Open jars that promote evaporation
- Porous materials to allow airing
Correct Answer: Moisture-proof packaging to prevent water uptake
Q31. How does calcium carbonate contribute to antacid formulations, occasionally used in dental care for oral pH?
- Acts as a strong organic acid
- Neutralizes acid by reacting to form CO2 and salts
- Releases fluoride to buffer pH
- Absorbs saliva to reduce pH
Correct Answer: Neutralizes acid by reacting to form CO2 and salts
Q32. Which microbial test is relevant for water-containing calcium carbonate dental formulations?
- Assay by titration
- Microbial limit test (total aerobic count and specified pathogens)
- Particle size analysis
- Viscosity profiling
Correct Answer: Microbial limit test (total aerobic count and specified pathogens)
Q33. Which parameter does not directly influence the RDA value of a toothpaste containing calcium carbonate?
- Particle shape and hardness
- Particle size distribution
- Formulation pH within normal range
- Color of the abrasive
Correct Answer: Color of the abrasive
Q34. Which solvent system is most appropriate for cleaning equipment after manufacturing calcium carbonate-containing toothpaste?
- Strong acids only
- Water with suitable detergents and chelating agents
- Nonpolar solvents like hexane
- Anhydrous ethanol exclusively
Correct Answer: Water with suitable detergents and chelating agents
Q35. Which endpoint indicates complete reaction in an acidimetric titration used to assay calcium carbonate?
- Appearance of persistent foam
- Neutralization indicated by pH or indicator change after CO2 evolution subsides
- Change in color to deep blue
- Solidification of the solution
Correct Answer: Neutralization indicated by pH or indicator change after CO2 evolution subsides
Q36. Which environmental contaminant must be minimized in calcium carbonate used for dental products for patient safety?
- Nitrogen oxides
- Lead and arsenic residues
- Natural flavors
- Ozone
Correct Answer: Lead and arsenic residues
Q37. Which manufacturing parameter is adjusted to produce GCC versus PCC?
- Degree of biological treatment
- Milling (mechanical grinding) versus chemical precipitation conditions
- Exposure to gamma radiation
- Fermentation time
Correct Answer: Milling (mechanical grinding) versus chemical precipitation conditions
Q38. Which characteristic of calcium carbonate makes it suitable as an opacifying agent in dental pastes?
- Low refractive index matching water
- High opacity and light scattering due to particle morphology
- Transparent nature
- Strong absorption in UV range
Correct Answer: High opacity and light scattering due to particle morphology
Q39. Which shelf-life concern is specific to calcium carbonate-containing fluoride dentifrices?
- Loss of calcium carbonate by sublimation
- Decreased fluoride availability due to interaction with calcium over time
- Increase in microbial count due to carbonate
- Spontaneous polymer formation
Correct Answer: Decreased fluoride availability due to interaction with calcium over time
Q40. Which excipient is commonly paired with calcium carbonate to improve texture and prevent hardening?
- Hydrophobic oils only
- Humectants such as glycerin or sorbitol
- Strong acids
- Simple sugars exclusively
Correct Answer: Humectants such as glycerin or sorbitol
Q41. Which physicochemical test helps ensure batch-to-batch consistency of calcium carbonate abrasives?
- Organoleptic test only
- Particle size distribution and specific surface area measurements
- DNA fingerprinting
- Viscometry of the dry powder
Correct Answer: Particle size distribution and specific surface area measurements
Q42. Which method is suitable to reduce microbial contamination risk when water is used during manufacturing of calcium carbonate pastes?
- Use of purified or potable water and preservative system
- Adding sugar to feed microbes beneficially
- Skipping microbial testing
- Using raw pond water
Correct Answer: Use of purified or potable water and preservative system
Q43. What is the primary crystalline form of naturally occurring calcium carbonate used industrially?
- Calcite
- Quartz
- Gypsum
- Halite
Correct Answer: Calcite
Q44. Which packaging material property is important to prevent degradation of calcium carbonate toothpastes?
- High oxygen permeability
- Low moisture vapor transmission rate (MVTR)
- High light transmission
- Porosity to air
Correct Answer: Low moisture vapor transmission rate (MVTR)
Q45. Which laboratory safety precaution should be used when weighing fine calcium carbonate powder?
- No protection required
- Use of local exhaust ventilation and dust mask
- Only gloves, no respiratory protection
- Store in open bowls to reduce dust
Correct Answer: Use of local exhaust ventilation and dust mask
Q46. Which property differentiates calcite and aragonite forms of calcium carbonate relevant to dental abrasives?
- They have identical crystal structures
- Different crystal habits and hardness affect polishing behavior
- Only color differs significantly
- One is organic, the other inorganic
Correct Answer: Different crystal habits and hardness affect polishing behavior
Q47. Which compatibility issue must be considered when adding antibacterial metal salts (e.g., zinc) to a calcium carbonate toothpaste?
- Zinc will always dissolve calcium carbonate
- Potential interaction affecting stability or taste and chelation with carbonate
- Zinc neutralizes fluoride chemically
- There are no possible interactions
Correct Answer: Potential interaction affecting stability or taste and chelation with carbonate
Q48. Which environmental consideration is associated with large-scale production of calcium carbonate?
- Generation of CO2 during calcination and quarrying impacts
- Production emits large amounts of chlorine gas
- It requires rare earth metals extensively
- It relies on biologically derived feedstocks only
Correct Answer: Generation of CO2 during calcination and quarrying impacts
Q49. Which test would you perform to confirm absence of excess soluble alkaline impurities in calcium carbonate?
- pH test of aqueous extract
- Melting point determination
- Optical rotation
- Flame photometry for sulfur
Correct Answer: pH test of aqueous extract
Q50. For exam-focused learning, which study approach best helps B. Pharm students master calcium carbonate in dental products?
- Memorizing only chemical formulas without applications
- Combining theory, formulation case studies, and practice MCQs
- Ignoring pharmacopeial standards
- Studying only marketing brochures
Correct Answer: Combining theory, formulation case studies, and practice MCQs
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