Endodontics · single question
What property of calcium hydroxide [Ca(OH)₂] is used in endodontic treatments?
Show answer and explanation
Correct answer: B. Bactericidal properties due to high alkaline pH
The primary property of calcium hydroxide used in endodontic therapy is its HIGH ALKALINE pH (~12.5), which is BACTERICIDAL — it destroys bacterial cell membranes and denatures bacterial enzymes. This is why it is used as an inter-appointment intracanal medicament. Its alkalinity also stimulates hard tissue formation (dentinal bridge for pulp capping). As an obturation material, Ca(OH)₂ is not ideal (does not seal the apex — MTA or gutta percha do). The bactericidal property is the PRIMARY endodontic use.
- A. Partially correct. Ca(OH)₂ does stimulate reparative dentin (used in pulp capping), but this is secondary to its bactericidal pH as the main endodontic property.
- B. CORRECT. The main property utilized in endodontics is bactericidal action from its highly alkaline pH (~12.5), which kills bacteria in the canal system during inter-appointment dressing.
- C. Incorrect. Ca(OH)₂ does NOT seal the apical foramen — it is resorbed and is not a definitive sealing material. MTA is used for apical sealing/plug.
- D. Incorrect. While Ca(OH)₂ has multiple properties, it does NOT reliably seal the apex — option C is incorrect.