Use of Non-Vital Pulp Therapies in Primary Teeth

Board takeaway

For a nonvital primary tooth, decide whether it is restorable, strategically worth retaining, and suitable for the required retention period.

• Intact or minimally resorbed roots favor pulpectomy.
• Extraction remains appropriate when infection cannot be controlled or the tooth has a poor restorative/support prognosis.

For selected resorbing teeth, lesion sterilization/tissue repair (LSTR) is a conditional short-retention option, not a substitute for checking contraindications.

• The 2026 exclusions below include excessive resorption, imminent exfoliation, perforation, ingredient allergy, and infective-endocarditis risk.
• Success requires clinical and radiographic healing.

Decision map

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Combine symptoms, examination, radiographs, restorability, successor status, and retention needs. The 2020 guideline favors pulpectomy with intact roots (conditional, low certainty) and LSTR over pulpectomy for selected resorbing teeth at 12 months (conditional, moderate certainty). The 2026 best practice excludes LSTR with ingredient allergy, excessive resorption, imminent exfoliation, perforated pulpal floor, or infective-endocarditis risk; resorption alone never overrides exclusions.

Diagnosis and treatment selection

• The 2020 guideline lists findings suggesting irreversible pulpitis/necrosis: spontaneous pain; sinus tract or other soft-tissue pathology; gingival swelling unrelated to periodontal disease; mobility unrelated to exfoliation; furcation/apical radiolucency; internal/external resorption.
• Normal pulp lacks reversible/irreversible pulpitis findings. The source describes reversible pulpitis as short provoked eating pain, approximately 5–10 minutes, without irreversible signs.
• Newer eligibility: the 2026 pulp best practice permits calcium-silicate pulpotomy in selected spontaneous-pain cases without infection, with vital radicular pulp and controllable bleeding.
  • Pain alone does not prove necrosis; a sinus tract or furcation infection does not qualify for this vital option.
• Bleeding uncontrolled after five minutes alone does not establish irreversible pulpitis.
• Diagnostic and extraction criteria are suggested from study inclusion criteria; no direct evidence-supported recommendation was possible.
• Pulpectomy removes infected pulp, instruments/irrigates canals, and fills with a resorbable material. LSTR places an antibiotic mixture in the chamber, usually without canal instrumentation or obturation.
• Modify planning for cooperation, medical complexity, inadequate anesthesia, limited opening, severe gag reflex, swelling, uncertain pain diagnosis, previous treatment complications, periodontal disease, age, cost, and family preferences.

Root resorption drives prognosis

• Pulpectomy without preoperative resorption: conditional recommendation, very low certainty at 12 and 24 months. Reported success was approximately 89% versus 47% with resorption at ≥12 months; comparisons have major limitations.
• Intact roots: prefer pulpectomy over LSTR—conditional, low certainty. Direct data favored pulpectomy, but the difference was not statistically significant.
• Significant resorption: LSTR over pulpectomy if retaining the tooth—conditional, moderate certainty at 12 months. Direct success estimates: 76% versus 47%.
• LSTR is a limited retention strategy, not assured long-term preservation.
• Two prospective studies had combined 24-month success of 37%; one 36-month report described bone loss, disturbed successor eruption, and a keratocyst in one case.

LSTR eligibility before choosing an antibiotic mixture

Apply the 2026 best practice's LSTR contraindications: ingredient allergy, excessive internal/external resorption, imminent exfoliation, a perforated pulpal floor, or infective-endocarditis risk excludes LSTR.

• Root resorption and a short retention horizon do not override these exclusions.
• For an eligible resorbing tooth, LSTR remains a conditional, limited-retention choice; it is not the routine alternative for intact roots.

Pulpectomy technique choices

• Visits: one or two visits may be selected for circumstances/expertise; no demonstrated 12-month success difference—conditional, very low certainty.
• Working length: tactile assessment, radiographs, or apex locator may be used; no demonstrated success difference—conditional, very low certainty. This does not prove equal measurement accuracy.
• Instrumentation: rotary saves approximately two minutes; success is comparable to hand instrumentation. Overall recommendation: conditional, moderate certainty; time-saving evidence itself was high certainty.
• More flush fills favored rotary numerically, without statistical significance. Consider equipment cost and training. Ribbon-shaped canals, fins, and isthmuses may require additional hand instrumentation and copious irrigation.
• Smear layer: inadequate evidence for a formal recommendation. Either approach may be chosen; proposed adaptation benefits must be balanced against possible tubule protection by the layer.
• Irrigation: NaOCl 1–5%, water/saline, or chlorhexidine may be selected—conditional, very low certainty. Comparisons were largely indirect; they do not establish superiority or equal safety.
• Isolation: rubber dam is identified as standard care and essential for avoiding contamination, despite insufficient comparative evidence to grade its effect on success.

Filling material, obturation, and restoration

• For expected retention ≥18 months, ZOE or zinc oxide/iodoform/calcium hydroxide may be better than iodoform/calcium hydroxide—conditional, very low certainty.
• Source examples: ZOE; Endoflas (ZO/iodoform/CH); Vitapex/Metapex (iodoform/CH).
• Network ranking at 18 months: ZO/iodoform/CH → ZOE → iodoform/CH. Success generally remained near 90% for the first two; iodoform estimates declined to 71% or less.
• Overall pairwise comparisons were not statistically significant; rankings do not establish definitive superiority. Calcium-hydroxide-only filler evidence was limited and excluded from the network analysis.

Place the filling and coronal restoration

• Delivery: Lentulo, hand plugger, or syringe may be chosen; neither flush-fill quality nor success differed significantly—conditional, very low certainty.
• Overfilling tended to reduce success. All delivery methods can produce voids; evidence cannot reliably quantify technique-specific clinical harm.
• Restoration: SSCs and fillings had comparable 12-month outcomes; limited 24-month data favored SSCs over composites. Same-day versus later placement showed no demonstrated difference—conditional, very low certainty.

LSTR antibiotic and instrumentation choices

• Prefer an alternate 3Mix without tetracycline/minocycline over traditional 3Mix—conditional, very low certainty; higher reported success and potential tetracycline adverse effects support this choice.
• Traditional mixture: minocycline, metronidazole, ciprofloxacin in a propylene glycol base. Alternate mixtures replace the tetracycline; clindamycin is one studied example. This guideline is not a dosing/compounding protocol.
• Filing/broaching before antibiotic placement is optional; no significant success difference—conditional, very low certainty.

Follow-up and adverse outcomes

• Evaluate treatment and adverse events clinically/radiographically at least every 12 months.
• Monitor LSTR closely during year one; if retained beyond 12 months, continue periodic examinations and radiographs at least annually. The source gives no fixed first-year visit schedule.
• A furcation radiolucency should diminish by six months or resolve to qualify as success. An unchanged lesion may represent persistent infection despite absent symptoms.
• Severe pain should not persist after 24–48 hours; reassess for failure. At 24 hours, pooled reports found 80% pain-free, 12% mild pain, and 8% moderate/severe pain.

Material-related follow-up

• ZOE: can resorb more slowly than roots, persist after exfoliation, and potentially deflect successor eruption. Extruded ZOE may persist for years.
• Iodoform fillers: may resorb faster than roots, leaving depleted canals by 12–18 months.
• Watch premature exfoliation, overretention, and successor eruption. Enamel defects were uncommon; observational evidence implicated earlier infection, resorption, or trauma rather than proving pulpectomy causation.

Evidence and practical implementation

• Based on a systematic review through January 2020, with GRADE assessment. Most recommendations are conditional and supported by low/very low certainty; shared decisions remain necessary.
• Tooth type and trauma comparisons could not support formal recommendations. Outcomes appeared broadly comparable; retrauma reduced success in one incisor study.
• Cost-effectiveness versus extraction remains uncertain. Discuss arch preservation, potential space maintenance, retreatment, child age, and retention horizon; emphasize prevention and a dental home.
• Standardized clinical/radiographic outcome definitions, consistent trial reporting, and longer follow-up are needed. A planned five-year updating process does not establish that a revision occurred.

Common board traps

Answer aloud

A restorable abscessed primary molar has intact roots. What guides treatment?

After confirming the nonvital diagnosis and need for retention, prefer pulpectomy over LSTR.

• Assess restorability, support, retention horizon, and alternatives.
• A restorable abscessed tooth is not managed by symptoms alone.
• Use rubber dam, a suitable resorbable filler, and a coronal seal.
• Extraction remains appropriate when infection cannot be controlled or retention/restoration is unsuitable.

Can an abscessed primary molar with external resorption exceeding 1 mm be retained?

Consider extraction first; selected eligible resorbing teeth may receive LSTR for a limited retention goal.

• The 2020 guideline conditionally favors LSTR over pulpectomy for up to 12 months in this group, with close surveillance.
• First exclude ingredient allergy, excessive resorption, imminent exfoliation, perforated pulpal floor, and infective-endocarditis risk under the 2026 best practice.
• Prefer a non-tetracycline mixture; do not promise retention through exfoliation.

How does the expected retention time affect primary-tooth pulpectomy filler choice?

For retention of at least 18 months, conditionally favor ZOE or zinc oxide/iodoform/calcium hydroxide over iodoform/calcium hydroxide alone.

• Evidence certainty is very low; network rankings do not prove definitive superiority.
• ZOE may persist after roots resorb or teeth exfoliate and affect successor eruption.
• Iodoform mixtures may resorb faster than roots, leaving depleted canals.

A tooth is comfortable but its furcation lesion is unchanged six months after nonvital therapy. Is treatment successful?

No symptom-only conclusion is justified; reassess persistent infection and management clinically and radiographically.

• Success includes radiographic healing; a furcation lesion should diminish by six months or resolve.
• Review at least annually, with closer first-year LSTR surveillance.
• Severe pain persisting beyond 24–48 hours also warrants reassessment.