Intracanal Medicaments
Clinical reference for intracanal medicaments used between appointments in endodontic treatment. Covers calcium hydroxide, triple antibiotic paste, the single-visit vs multi-visit decision framework, and inter-appointment seal considerations. Treatment decisions should be guided by clinical findings and individual patient factors.
Last updated: 14 Apr 2026
1. Single-Visit vs Multi-Visit Decision
Current Evidence
The ESE S3 Clinical Practice Guideline (2023) provides a strong recommendation (⇑⇑) for single-visit treatment without inter-appointment calcium hydroxide, where adequate clinical procedures have been performed. The supporting evidence is of moderate quality for radiographic healing outcomes.
This recommendation applies specifically when adequate chemo-mechanical debridement has been achieved. The key qualifier is “where adequate clinical procedures have been performed” — this presupposes thorough instrumentation and irrigation.
When Multi-Visit May Be Appropriate
- Persistent purulence or exudate that cannot be controlled in a single appointment
- Complex anatomy where adequate disinfection cannot be confirmed
- Regenerative endodontic procedures (immature necrotic teeth)
- Symptomatic cases not responding to initial treatment
- Cases where obturation needs to be delayed for clinical reasons (e.g., time constraints, pending definitive restoration plan)
2. Calcium Hydroxide — Ca(OH)₂
Mechanism of Action
- High pH (~12.5) disrupts bacterial cell membranes
- Neutralizes bacterial lipopolysaccharide (LPS)
- May promote periapical healing through its alkaline environment
Placement
- Delivered via lentulo spiral, syringe (e.g., MAP system), or hand-carried on files
- The canal should be filled densely; voids may harbor residual bacteria
- Aqueous vehicles (water, saline) provide faster ion release; viscous vehicles (glycerin, PEG) provide slower, sustained release
Duration
- Traditional protocol: 7–14 days minimum
- Prolonged use (>3 months) may weaken root dentin, particularly in immature teeth
- The bactericidal effect generally peaks within 1–2 weeks
Removal
- Flush with NaOCl followed by EDTA
- Ultrasonic or sonic activation may aid removal
- Complete removal can be challenging — micro-CT studies suggest residual material frequently remains even after thorough flushing
When Ca(OH)₂ May Be Appropriate
- Weeping canal with persistent exudate that cannot be dried
- Large periapical lesion with active drainage
- Traumatic injuries with external inflammatory resorption
- Inter-appointment management when obturation is delayed
- As part of regenerative endodontic protocols (AAE 2021 recommendation)
3. Triple Antibiotic Paste (TAP)
TAP is indicated specifically for regenerative endodontic procedures (REPs) in immature necrotic permanent teeth. It is not intended for use as an inter-appointment dressing in conventional root canal treatment.
Formulation
- 1:1:1 ratio — ciprofloxacin : metronidazole : minocycline
- Target concentration: 1–5 mg/mL (AAE Clinical Considerations, revised May 2021)
- Delivered via syringe into the canal system
Clinical Considerations
- Minocycline may cause crown and root discoloration
- Consider sealing the pulp chamber with a dentin bonding agent before TAP placement to reduce staining
- Keep the paste below the CEJ to minimize discoloration risk
- Higher concentrations may be cytotoxic to stem cells — the AAE recommends 1–5 mg/mL
Alternatives
- DAP (double antibiotic paste) — omits minocycline to avoid staining
- Substitution of minocycline with clindamycin, amoxicillin, or cefaclor
- Ca(OH)₂ — listed alongside TAP as a medicament option in the AAE regenerative protocol
4. Other Medicaments
Chlorhexidine Gel (2%)
Provides substantivity (sustained antimicrobial effect) but cannot dissolve organic tissue. Not recommended by the ESE as an inter-appointment dressing. May be considered as an adjunct in specific situations.
Ledermix (Corticosteroid + Antibiotic)
Historically used for pain management; limited current evidence supporting routine use. May reduce inter-appointment pain in symptomatic cases.
Iodoform-Based Pastes (e.g., Vitapex)
Primarily used in pediatric endodontics for primary tooth pulpectomy. Resorbable formulation designed for teeth with physiologic root resorption.
5. Inter-Appointment Seal
Coronal leakage between appointments can negate the effects of intracanal disinfection. Maintaining an adequate temporary seal is an important consideration in multi-visit treatment.
| Material | Setting | Thickness | Notes |
|---|---|---|---|
| Cavit (ZOE-based) | Moisture-activated | Generally ≥3.5 mm for adequate seal | Widely used; simple to apply; may not withstand heavy occlusal forces |
| IRM (reinforced ZOE) | Chemical set | ≥2 mm | More durable than Cavit for longer inter-appointment periods |
| Glass Ionomer | Chemical set | ≥2 mm | Fluoride release; bonds to tooth structure |
| Composite (flowable or packable) | Light-cured | Per clinical need | Provides strong seal; may be preferred when longer intervals are anticipated |
The temporary restoration should provide an adequate barrier against salivary contamination. Consider the anticipated duration between appointments when selecting the material.
6. Frequently Asked Questions
Should I use calcium hydroxide between appointments?
The ESE S3 Clinical Practice Guideline (2023) provides a strong recommendation for single-visit treatment without inter-appointment calcium hydroxide, where adequate clinical procedures have been performed. Multi-visit treatment with Ca(OH)₂ may still be appropriate in specific situations such as persistent exudate, complex anatomy, or regenerative protocols.
What is triple antibiotic paste and when is it used?
Triple antibiotic paste (TAP) is a 1:1:1 mixture of ciprofloxacin, metronidazole, and minocycline at 1–5 mg/mL concentration. It is used specifically in regenerative endodontic procedures for immature necrotic permanent teeth, as outlined in the AAE Clinical Considerations (2021). TAP is not intended for routine use in conventional root canal treatment.
References
- Duncan HF, El-Karim I. "Endodontic S3-level clinical practice guidelines: the ESE process and recommendations" — Br Dent J (2025);238(7):580-586. PMC11991915
- ESE S3-level Clinical Practice Guideline — Int Endod J (2023);56:238-295. DOI 10.1111/iej.13974
- AAE Clinical Considerations for a Regenerative Procedure — Revised May 2021
- Siqueira JF Jr, Lopes HP. "Mechanisms of antimicrobial activity of calcium hydroxide: a critical review" — Int Endod J (1999);32:361-369. PMID 10551109
- Mohammadi Z, Dummer PMH. "Properties and applications of calcium hydroxide in endodontics and dental traumatology" — Int Endod J (2011);44:697-730. PMID 21535021
- Sathorn C et al. "Effectiveness of single-versus multiple-visit endodontic treatment of teeth with apical periodontitis: a systematic review and meta-analysis" — Int Endod J (2005);38:347-355. PMID 15910469
- Sjogren U et al. "Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis" — Int Endod J (1997);30:297-306. PMID 9477818
- Kenee DM et al. "Quantitative assessment of efficacy of various calcium hydroxide removal techniques" — J Endod (2006);32:563-565. PMID 16728251
Disclaimer
This information is for educational purposes only. Always follow clinical judgment and manufacturer guidelines. It should not be used as the sole basis for clinical decision-making.