Calcium hydroxide vs MTA for 10 marks
Reading File
Finding Sources
Searching PubMed
"calcium hydroxide" AND "mineral trioxide aggregate"
Searching the Web
calcium hydroxide versus mineral trioxide aggregate direct pulp capping systematic review
Calcium hydroxide vs Mineral Trioxide Aggregate (MTA)
Both are bioactive materials used in vital pulp therapy, pulp capping, pulpotomy, apexogenesis, and management of immature teeth. MTA has largely replaced calcium hydroxide in many indications because of its better seal and more predictable hard-tissue formation.
| Feature | Calcium hydroxide [Ca(OH)₂] | Mineral trioxide aggregate (MTA) |
|---|---|---|
| Composition | Calcium hydroxide powder/paste with vehicle and radiopacifier | Calcium silicate-based cement: tricalcium silicate, dicalcium silicate, tricalcium aluminate, calcium sulfate and bismuth oxide radiopacifier |
| pH | About 12.5 | About 12.5 after hydration |
| Mechanism | High alkalinity causes superficial necrosis of pulp, stimulates underlying cells to form reparative dentin | Releases calcium ions, forms calcium hydroxide during setting, stimulates cementogenesis, dentin bridge formation and hard-tissue repair |
| Antibacterial action | Strong antibacterial action due to high pH | Antibacterial, but generally less pronounced than calcium hydroxide initially |
| Setting reaction | No true set in paste form; may dissolve over time | Hydrophilic cement that sets in the presence of moisture |
| Setting time | Immediate placement, no setting reaction required | Long setting time, traditionally about 2-4 hours, which is a disadvantage |
| Solubility | High solubility and disintegration over time | Low solubility after setting, with better dimensional stability |
| Sealing ability | Poorer seal; permits microleakage | Excellent marginal seal; expands slightly on setting and forms hydroxyapatite-like interfacial deposits |
| Dentin bridge | Forms a dentin bridge, but it may be porous and show tunnel defects | Forms thicker, more uniform and less porous dentin bridge |
| Pulp response | Initial inflammation and superficial tissue necrosis are common | Better biocompatibility and less inflammation; promotes pulp healing |
| Handling | Easy to manipulate and inexpensive | Difficult handling, sandy consistency, technique sensitive |
| Cost | Cheap and widely available | Expensive |
| Colour change | Does not usually discolor tooth structure | Grey MTA can discolor teeth; white MTA reduces but does not completely eliminate this concern |
| Compressive strength | Low | Higher than calcium hydroxide, though lower than many restorative materials |
| Clinical success in direct pulp capping | Good short-term results but lower long-term predictability | Higher long-term pulp vitality and success rate than calcium hydroxide |
| Common uses | Intracanal medicament, apexification, indirect pulp treatment, temporary dressing | Direct pulp capping, partial/full pulpotomy, apexogenesis, root-end filling, perforation repair, regenerative endodontics |
Advantages of calcium hydroxide
- Inexpensive and readily available.
- Easy placement and removal.
- Strong antibacterial effect.
- Useful as an intracanal medicament and in conventional apexification.
- Stimulates hard-tissue barrier formation.
Disadvantages of calcium hydroxide
- Dissolves over time and provides an inadequate long-term seal.
- Dentin bridge may contain tunnel defects, allowing bacterial leakage.
- May produce superficial pulp necrosis and persistent inflammation.
- Lower fracture resistance of root dentin if used long term as an intracanal dressing.
- Lower success rate than MTA in direct pulp capping and pulpotomy.
Advantages of MTA
- Excellent biocompatibility.
- Hydrophilic, so it can set in a moist environment.
- Superior sealing ability and low microleakage.
- Promotes predictable dentin bridge formation, cementogenesis, and periodontal healing.
- Useful in multiple endodontic procedures, including perforation and root-end repair.
- Produces better long-term outcomes in vital pulp therapy.
Disadvantages of MTA
- Expensive.
- Long setting time.
- Difficult handling and placement.
- Potential tooth discoloration, especially with grey MTA.
- Cannot be easily removed after setting.
Conclusion
Calcium hydroxide remains useful as an inexpensive antibacterial intracanal medicament and for selected pulp-therapy procedures. However, MTA is generally preferred for direct pulp capping, pulpotomy, apexogenesis, root-end filling, and perforation repair because it provides a superior seal, better biocompatibility, and more predictable hard-tissue healing. Systematic reviews report better long-term vitality outcomes with MTA for direct pulp capping and vital pulp therapy, including a direct pulp-capping meta-analysis and a 2025 vital pulp therapy review.
This is a shared conversation. Sign in to Orris to start your own chat.