How to Treat Cracked Teeth

Management counterpart to Diagnosis of Cracked Teeth. Content derived from the AAE Colleagues for Excellence issue AAE cracked teeth_formatted_text (Krell, 2022). For terminology and diagnostic workup, see the sibling diagnosis note.

The cracked-tooth spectrum runs from harmless surface marks to catastrophic root failure. Treatment is decided by where on this spectrum the tooth sits, the depth and location of the crack, and the periodontal probing associated with it. The single most consistent message from the outcome literature: not all cracked teeth need root canal treatment, but all cracked teeth need a crown.

Management by Crack Type Along the Spectrum

• Craze lines (infractions) — cracks of enamel only, no loss of tooth structure. No treatment required beyond reassurance; monitor and address parafunction/occlusion if relevant.
• Fractured cusp — a complete fracture originating from the crown, usually involving a cusp and ending in a cervical area. Remove the loose segment and restore with a cuspal-coverage restoration (onlay/crown). Pulp is usually unaffected; prognosis is good.
• Cracked tooth — surface disruption of enamel and dentin (possibly cementum) of unknown depth. The key management problem. Immediate occlusal reduction, definitive cuspal-coverage / full crown, and root canal treatment only if symptoms progress to irreversible pulpitis/necrosis. See Managing the Cracked Tooth below.
• Split tooth — the crack has propagated completely through the tooth, dividing it into separable segments. Often unrestorable; prognosis depends on the position of the split. Posterior teeth may sometimes be saved by removing a segment (hemisection on a multi-rooted tooth), otherwise extract.
• Vertical root fracture (VRF) — fracture confined to / extending into the root. Single-rooted → extract; multi-rooted → root resection / amputation / hemisection. See Vertical Root Fractures below.

Managing the Cracked Tooth

The protocol has shifted over the last 15 years toward reducing repetitive load and protecting the tooth as early as possible.

1. Take the tooth out of occlusion immediately. Reduce the occlusion at the initial visit — repetitive bruxing/grinding forces propagate the crack toward fracture. Instruct the patient to chew on the contralateral side until definitive restoration.
2. Cuspal coverage / crown is the key to prognosis. All cracked teeth require a crown as part of treatment.
   • Cracked teeth with reversible pulpitis and normal apices that were immediately crowned had an ~80% chance of never needing root canal treatment.
   • Early crown placement on a cracked tooth has been shown to improve prognosis by ~98% over an 11-year period.
3. Root canal treatment if pulp deteriorates. If symptoms persist and irreversible pulpitis or necrosis develops, perform RCT — it is more successful than previously thought (~84% survival at 60 months). If a crown was already placed for reversible pulpitis, RCT can be done through the existing crown and the access restored without replacing the crown.
4. Orifice barriers to the deepest crack extent. After obturation, place orifice barriers down to the deepest visible extent of the crack (under the surgical operating microscope) to help seal against bacterial penetration and reinforce the root. Davis & Shariff’s protocol (orifice barriers + out of occlusion + 6-month recall) achieved a 97% survival rate at 4 years.
5. Timing of the definitive crown. Place the crown as soon as possible after RCT. For reversible-pulpitis cases, a well-fitted temporary crown may be left until symptoms subside, then converted to a definitive crown.
6. Close recall. Strict recall (every ~6 months) with ongoing occlusal monitoring is integral to the favourable survival figures above.

Iowa Staging Index — Prognosis Guide

The Iowa Staging Index communicates likely outcomes to the patient. Three factors drive prognosis after RCT + crown:

• Periodontal probing depth associated with the crack (< 5 mm vs ≥ 5 mm).
• Crack location (distal marginal ridge cracks fare worse than mesial).
• Apical pathosis at presentation (any apical periodontitis / abscess lowers success).

Stage	Probing	Crack location	Apical pathosis	”Success” rate	Decision lean
1	< 5 mm	Mesial marginal ridge	None	93% (survival up to 97%)	Treat — favourable
2	< 5 mm	Distal marginal ridge	None	84%	Treat
3	< 5 mm	Distal marginal ridge	Present	69%	Treat, guarded
4	≥ 5 mm	Any marginal ridge	±	41%	Guarded — consider extraction

• Probing < 5 mm favours treatment (RCT + crown).
• Probing ≥ 5 mm associated with a crack markedly decreases survival and pushes the decision toward extraction. Two meta-analyses and a large retrospective study agree: probing ≥ 5 mm lowers survival, and timely crown placement improves it.

Vertical Root Fractures

VRFs carry a guarded-to-hopeless prognosis. Endodontically treated teeth (especially those with posts or excessive radicular dentin removal) are at greatest risk, though non-endodontically treated teeth can fracture from repetitive load.

• Single-rooted teeth → extract. No reliable treatment has been developed; these teeth generally require extraction.
• Multi-rooted teeth → save the sound root(s). Remove the fractured root and restore the remainder rather than extracting — outcomes can exceed those of single-tooth implants:
  • Root amputation: ~92% survival over 12 years.
  • Hemisection: ~79–91% survival over 7–30 years.
• Implant vs tooth. Compromised natural teeth may outlast the average implant; single-tooth implants involved ~4× the appointments and ~2× the cost of RCT + crown for equivalent success. Natural dentition preserves bone — preserve it where a documented option exists.
• These resective procedures may require referral to a specialist.

Decision Summary

Presentation	Treatment	Prognosis
Craze line (infraction)	Reassure, monitor, manage parafunction	Excellent
Fractured cusp	Remove segment + cuspal-coverage restoration	Good
Cracked tooth, reversible pulpitis, probing < 5 mm	Out of occlusion → early crown; RCT only if pulp deteriorates	~80% avoid RCT; up to 97% survival
Cracked tooth needing RCT, probing < 5 mm	RCT + orifice barriers to crack depth + early crown + recall	~84% survival at 60 mo; 97% at 4 yr (Davis & Shariff)
Cracked tooth, probing ≥ 5 mm (Iowa Stage 4)	Guarded — RCT + crown vs extraction	~41% success — consider extraction
Split tooth	Remove segment / hemisection if multi-rooted, else extract	Variable to poor
VRF, single-rooted	Extract	Hopeless for the tooth
VRF, multi-rooted	Root resection / amputation / hemisection + restore sound root(s)	79–92% survival

Key Takeaways

• Get the tooth out of occlusion immediately and crown it early — these two steps drive prognosis.
• Every cracked tooth needs a crown; not every cracked tooth needs RCT.
• Use the Iowa Staging Index: probing < 5 mm favours treatment; ≥ 5 mm favours extraction.
• Place orifice barriers to the deepest crack extent when RCT is performed.
• VRF single-rooted → extract; multi-rooted → resect/amputate/hemisect and keep the sound root(s).