OCHWA Endodontic Guidelines

Quick-reference protocol for root canal treatment (RCT) at the UWA Oral Health Centre. Compiled from a. 2013 UWA Endodontic Guidelines and Root Canal Treatment Comprehensive Clinical Guide. RCT is typically delivered over three appointments: (1) examination, diagnosis and stabilisation; (2) root canal preparation; (3) root canal filling — though this varies with diagnosis, tooth complexity, treatment response and operator skill.

Scope

The 2013 UWA guidelines define the clinic’s appointment structure, forms, irrigation regime and medicament protocol (Hedström-file hand preparation). The Comprehensive Clinical Guide (Elkholy) updates the preparation and filling techniques to the ProTaper Ultimate rotary system and current evidence on filling timing. Where they differ, follow current clinic teaching.

Initial Appointment & Diagnosis

Aim: examine, diagnose, gain informed consent, then investigate and stabilise the tooth with a medicament and interim restoration.

Forms & ADA item codes

• Form 70 — endodontic examination form; must be used and fully completed for ALL endodontic cases.
• Form 71 / Form 72 — treatment records. Form 71 has tables for rubber dam technique and RCT details (working lengths, file sizes); Form 72 continues when Form 71 is full on both sides.
• Relevant ADA item codes: 019 (consultation / referral to specialist), 022 (intraoral periapical radiograph — per film), 221 (complete chemo-mechanical preparation and root filling, one canal). Record codes used on the treatment form.

Examination

• History of the presenting problem — essential.
• Clinical exam: pulp sensibility (CO2 + electric pulp test), transillumination, mobility, percussion, palpation, restoration assessment, periodontal probing, discolouration, swelling.
• Transillumination — intense light from multiple angles; highlights cracks and caries. Transilluminate ALL teeth when assessing pulp/periapical status, and repeatedly during investigation.
• Identify the CAUSE — the pathway of bacterial entry causing the pulp/periapical disease.
• Radiographs — modified parallel technique with a RINN XCP positioning device. Some teeth need a tube-shift view in addition to the straight-on view.

Diagnosis (must note all four)

1. The tooth (FDI number).
2. State of the pulp / root canal system.
3. State of the periapical tissues.
4. Cause(s) of the disease.

Consent & local anaesthesia

• Patient must understand diagnosis, cause, and management plan, and give informed consent. Advise that feasibility is confirmed only after tooth investigation — outcome is either proceed with RCT or extract.
• LA (lignocaine preferred) for all appointments until root canal preparation is complete. LA is NOT needed for dressing changes or filling appointments.

Tooth investigation (case selection)

• Remove ALL existing restorations, caries and cracks (except cracks confined to enamel) to judge remaining tooth structure and restorability.
• Recommended bur: high-speed tungsten carbide Jet #331 (use Beaver #1931 for porcelain). Water coolant may be off (pulp needs no thermal protection) — improves vision; use short applications, no pressure.
• Once the pulp chamber is opened: stop using the triplex syringe. Irrigate only with EDTAC. Locate canal orifices with a DG16 probe and perform initial canal negotiation.
• Confirm restorability (sufficient structure? how to restore? what interim restoration?). If not restorable → simple temporary, advise poor prognosis, arrange extraction.

Initial canal negotiation & irrigation

• Initial negotiation with a small Hedström file (size 10 or 15) using: slight rotation (max 1/8 turn), push-pull cutting on withdrawal, and circumferential filing. Full working length not required yet.
• Irrigation at this visit: EDTAC only (cetrimide aids cleaning and orifice location).

Initial medicament (by pulp/canal diagnosis)

Diagnosis	Initial medicament
Acute/chronic irreversible pulpitis	Ledermix paste
”Elective” RCT (rare)	Ledermix paste
Necrotic/infected pulp, pulpless & infected, or root-filled & infected	50:50 Ledermix + calcium hydroxide paste

• Place with a small Hedström file rotated anti-clockwise (no spiral filler unless the canal is naturally wide).
• Keep medicament in the canal only, not the crown (avoids discolouration, esp. anteriors).
• 50:50 mix options: mix equal Ledermix + Calasept Plus on a slab and place; or place Ledermix then Pulpdent so they mix in-canal. Variations apply for trauma, resorption, open apices, perio-endo lesions — consult condition-specific notes.

Closing & interim restoration

• Small sterile cotton pellet on the chamber floor, then Cavit (build up 2-3 mm for easy relocation).
• Interim restorations: glass ionomer — Ketac Silver (posterior, no aesthetic concern) or Ketac Fil (anterior/aesthetic premolars). Condition dentine (and enamel) with Ketac Conditioner; protect with Ketac Glaze while setting (cotton pellet, not mini-tips).
• Stainless steel bands when a cusp is missing or the restoration may fracture/dislodge — band cemented with the same Ketac material.
• Anterior interim crowns: cold-cure acrylic (Luxatemp) ± polycarboxylate form; cement with IRM or zinc phosphate (NOT TempBond/TempCem — no evidence of bacterial seal over 4-6 wks).
• Remove the interim restoration from all occlusal contact (centric + excursions) to protect the tooth and reduce post-op pain.

Inter-appointment interval

Minimum 4 weeks (up to 6 acceptable). Ledermix and 50:50 mixes take 3-4 weeks to be fully effective, and periapical inflammation needs ≥4 weeks to show resolution.

Root Canal Preparation

Second appointment — reassess that symptoms/signs have resolved, then complete preparation. Use LA (apical nerve fibres may persist; working length not yet established) and rubber dam (cuff technique).

Rubber dam (mandatory, all stages)

Rubber dam is mandatory for every RCT stage including investigation, post preparation/placement, and definitive restoration. Prefer the cuff technique (better access/vision); use single-tooth isolation only for the last standing tooth in an arch.

Tooth type	Single-tooth clamp	Cuff-technique clamp
Upper / lower incisors	9t	2t on 1st premolar (same side); for 31/41 alt. #00 on 32/42
Upper / lower canines	9t or 2t	2t on 1st/2nd premolar (same side)
Upper premolars	2t	14,15: 13a on 16 · 24,25: 12a on 26
Lower premolars	2t	#4 on 1st molar (same side)
Upper molars	16,17: 13a · 26,27: 12a · 18,28: 2a	16: 13a on 17 · 26: 12a on 27 · 17,27: 2a on 18/28
Lower molars	#4	#4 on the next molar distally (same side)

Access & negotiation

• Access through the interim restoration with the Jet #331 bur (coolant may be off). Locate and remove all Cavit + cotton pellet; irrigate with EDTAC (never triplex).
• Negotiate canals with small Hedström files to the estimated working length. Get at least a size 15 to length before the working-length radiograph (smaller tips are not visible on film).

Working length

• Establish radiographically with the modified parallel technique; an apex locator may assist but a film is still required (apex locators may read long → periapical inflammation / foreign-body reaction).
• File in every canal on the working-length film; use tube-shift views for multi-canal teeth (e.g. mesial shift for lower molars; distal shift for upper molars MB root, mesial for DB root).
• Aim to finish at the apical constriction (dentino-cemental junction) — narrowest point, natural barrier against extrusion. Do not violate/enlarge it.
• Establish working length and prepare canals at the same appointment (consistent measuring). Record file lengths on Form 71 as removed.

ProTaper Ultimate sequence (current technique)

Pre-enlarge crown-down: more irrigant volume, better apical access, less instrument stress. Most teeth 19-25 mm; calcification is heaviest coronally, apical third usually patent.

Step	Instrument / action	Notes
1	Scout coronal third — K-file 08/10	Assess diameter, anatomy (merge/curve/recurve/dilacerate/divide), confirm straight-line access (upright handle)
2	SX (Orifice Opener)	Light pecking, coronal third only, engage walls laterally; irrigate NaOCl, re-scout
3	Slider then Shaper to mid-canal	Insert without rotation until engaged, then rotate with ~1 mm in-and-out pecks
4	Apical negotiation — 08K/10K, watch-winding	Establish patency to the root end
5	Working length	Apex locator + radiographic confirmation
6	Glide path — K-files to size 15	File must be “super loose” at WL before rotary
7	Sequential enlargement: Slider → Shaper → F1 → F2 (→ F3 if gauging indicates)	Irrigate ≥2 mL NaOCl + patency check between files
8	Apical gauging	Size-25 K-file to WL; if loose, step up to F3 and re-gauge

Rotary safety

Light pencil-pressure, 1 mm pecking increments, fingertips near the tip. Never force apically (ledge/transportation/separation risk). At any screw-in or binding, switch to a less aggressive taper or pre-enlarge coronally. “Just kiss the apex” — minimise rotary time at full WL. Narrow canals may finish at F1; for curved canals prepare the straight coronal portion first and preserve curvature.

Hedström hand preparation (alternative / supplementary)

Sequential increasing Hedström files producing a constantly tapering cone. Minimum apical size 25 (for canals initially ≤ size 20); naturally larger canals are enlarged one or more sizes beyond the first binding file. Adequate when the final file reaches WL freely, stops at an apical seat, and is loose in the prepared (well-tapered) canal.

Irrigation & Medicaments

Irrigation regime (UWA-researched)

• EDTAC 15% — during ALL filing (reduces inorganic smear layer; cetrimide lubricates). Never use NaOCl while filing (creates an inorganic smear layer that is hard to remove).
• NaOCl 1% — after enlargement, to disinfect and dissolve organic tissue: flush, leave 30-60 s, repeat for ≥5 min; agitate with a size-15 file (no wall cutting). (Elkholy guide uses 2.5% NaOCl throughout rotary preparation — follow current teaching for the chosen technique.)
• EDTAC final flush — 2-3 min after NaOCl to dissolve residual inorganic smear. Then dry by aspiration + paper points.
• Syringe technique: 3 mL Luer-Lok, closed-ended (polypropylene) needle near WL; open-ended needles kept 2 mm short. Effective exchange zone is only 1-1.5 mm past the needle tip — avoid wedging and excessive pressure.

Medicament after preparation (by diagnosis)

Diagnosis	Medicament
Acute/chronic irreversible pulpitis	50:50 Ledermix + Ca(OH)₂
”Elective” RCT	50:50 Ledermix + Ca(OH)₂
Necrotic/infected, pulpless & infected, root-filled & infected	Ca(OH)₂ alone (Pulpdent — methyl-cellulose base, easy to place/remove)

• Place with a spiral filler (low speed, forward, kept 3-4 mm short of WL). Keep medicament in the canal only.

Ca(OH)₂ medication timing (current evidence)

Optimal 1-2 weeks between appointments; minimum ~7 days for antimicrobial efficacy. Efficacy diminishes over time (dentine/fluid buffering, CO₂ carbonation to inert CaCO₃). Avoid > 1 month — long-term Ca(OH)₂ weakens dentine (collagen degradation) and increases root-fracture risk, especially in immature/thin roots. (The 2013 UWA minimum inter-appointment interval is 4 weeks; reconcile with current short-medication evidence per clinic teaching.)

Temporary restoration of access cavity (double layer)

Small cotton pellet on chamber floor, then Cavit (inner — moisture barrier, activate with damp pellet) followed by IRM (outer — antibacterial via eugenol, wear-resistant, finished flush and out of occlusion). Use hand-mixed IRM. No evidence supports GIC-over-GIC inside the access cavity.

Root Canal Filling

Third appointment — reassess resolution. LA is contraindicated (it masks extruded medicament, residual pulp, over-long WL, or perforation — all must be excluded first). Rubber dam (cuff) essential.

• Re-access (remove IRM + Cavit with Jet #331, EDTAC irrigation). Remove medicament by copious EDTAC + size-15 agitation; re-negotiate to WL with a file one size smaller than the last. Use EDTAC only at this visit (no NaOCl — organic tissue already removed). Dry with paper points until completely dry.
• If a canal keeps weeping after multiple paper points (periapical exudate), do not fill — re-medicate with Ca(OH)₂ for ~2 weeks and reassess.

Filling techniques

• Materials: gutta-percha core + sealer. UWA legacy sealer AH26 (long working time). Modern options: resin-based AH Plus (1:1 mix, glossy, ~1 cm string, 4-hr window) or hydraulic calcium-silicate sealers (pre-mixed, set with moisture, slight expansion).
• Master cone: match the final prep (e.g. F2 GP for an F2 prep); should reach WL with slight resistance and tug-back; confirm radiographically at 0.5-1 mm from the radiographic apex. Trim with a blade (0.5 mm at a time) or step up a size as needed.

Technique	When preferred	Method summary
Single cone	Hydraulic calcium-silicate sealers (slight set expansion); matched-size GP only	Coat canal walls + apical 2/3 of master cone with sealer; seat to WL; sever at orifice with a heated instrument; vertical plugger compaction
Lateral condensation	Resin-based sealers (offsets shrinkage); legacy UWA technique	Master cone + D11 spreader to within 1-2 mm of WL; add fine accessory points (uncoated) until spreader penetrates only 3-4 mm (CEJ level); 3-8 points typical; heated plugger to sever and vertically compact

• UWA legacy lateral compaction: D11T spreader with “Fine-Fine” accessory points for the apical third (radiograph), then D11 spreader with “Fine” points for the middle/coronal thirds; warm plugger (5/7 or modified spreader) coronally.
• Clean the chamber with an alcohol-soaked cotton pellet (removes resin sealer). Final radiograph: GP within 0.5-2 mm of the radiographic apex, uniform density, no voids.
• Post-fill: place an immediate coronal seal (double-layer Cavit + IRM, or GIC) and take a post-operative radiograph (RINN XCP, for later comparison).

Definitive Restoration & Review

• Definitive restoration as soon as possible after filling (research shows better outcomes/longevity). Delay risks re-infection if interim/temporary restorations break down. Rubber dam mandatory during the definitive restoration, including post preparation and post placement.
• Review at 6 months: history + clinical exam + periapical radiograph (RINN XCP, same angulation as pre/post-op). If healing incomplete → re-review at 12 months; if complete → re-review in 3-4 years. Radiographic healing is slow (1-4 yrs); a significant lesion reduction at 1 year predicts success — do not delay filling waiting for full radiographic resolution.

Other Notes

Post-treatment pain — the 3D’s

Diagnosis → Dental treatment → Drugs (in that order; dental treatment relieves the inflammation driving the pain). Manage with NSAIDs (most effective); use paracetamol ± codeine if NSAIDs contraindicated.

Pain level	NSAIDs permitted	NSAIDs contraindicated
Mild	Ibuprofen 400 mg q4h	Paracetamol 500-1000 mg q4h
Moderate	Ibuprofen 400-600 mg q4h + paracetamol 1000 mg q4h	Paracetamol 1000 mg + codeine 60 mg q4h
Severe	Ibuprofen 400-600 mg q4h + paracetamol 1000 mg with codeine 60 mg q4h (alternate at 2-hourly intervals)	Paracetamol 1000-1500 mg + codeine 60-90 mg q4h

• Higher doses on 1-2 occasions only. Analgesics usually needed 1-3 days only — persistent pain warrants reassessment. Max daily: ibuprofen 2400 mg, paracetamol 4000 mg, codeine 360 mg.

Antibiotics

• Rarely required; an adjunct to dental treatment, never a substitute and never for pain control. Prefer local (intra-canal) over systemic.
• Indications: definite bacterial infection likely to respond, systemic illness/malaise (fever), lymph-node involvement, cellulitis/spreading infection, rapid onset (<24 h), or immunocompromise.
• First choice: phenoxymethylpenicillin (Pen V) 500 mg every 6 h (1 h before meals); loading dose 1000 mg often advantageous. IV/IM penicillin in severe cases. Amoxicillin generally too broad-spectrum for odontogenic infections.

Drainage

• Only for a fluctuant swelling of an acute apical abscess. Achieve drainage via the root canal by starting RCT promptly; investigate the tooth; always place a medicament (50:50 Ledermix + Ca(OH)₂, or Ca(OH)₂ alone) and close with an interim restoration. NEVER leave a tooth open to drain.

Root canal re-treatment

• Follow standard RCT principles; the difference is removing existing filling material first. Use eucalyptus oil as the GP/cement solvent (small volume; keep off the rubber dam — it perforates it).
• Remove coronal GP with a Gates-Glidden bur (size 3 for 2-3 mm, then size 2; or size 2 alone), then Hedström files for the apical two-thirds (e.g. size 25 mid-canal → size 20 apically).

Assessing root-filled teeth before a new restoration

• Assessment is mainly radiographic and limited. In general, replace all old root fillings before re-restoring — especially before posts/cores and full-coverage crowns — because failing/leaking restorations contaminate the canal. Even “clinically satisfactory” restorations may harbour bacteria; periapical radiolucency lags infection by 1-2 to >10 months, so its absence does not exclude apical periodontitis.