Open Apex – found in developing roots of immature teeth
Normal in the absence of pulp or periradicular disease
If pulp necrosis occurs before root formation is complete: dentin formation ceases and root growth is arrested
Open apex represents a key challenge for achieving a reliable apical seal with conventional obturation unless barrier formation is achieved
Definitions and Key Concepts
Apexification (Root-End Closure)
Also called Apexification
Defined as the process of creating an environment within the root canal and periapical tissues after pulpal death that allows a calcific barrier to form across the open apex
Apexogenesis (Vital P pulp Therapy)
Vital pulp therapy aimed at continued physiological root development in teeth with immature roots
Regenerative Endodontics (Regendo)
Regenerative procedures aiming to restore pulpal tissue and continued root development
Root Canal Therapy (RCT)
Conventional treatment for necrotic or irreversibly inflamed pulpal tissue in teeth with closed apex
Indications and Contraindications for Root-End Closure and Vital Pulp Therapy
Indications for Root-End Closure / Apexification
Restorable immature tooth with pulp necrosis
Irreversible Pulpitis with Necrotic Pulp
Contraindications for Root-End Closure (Apexification) in general
All vertical root fractures and most horizontal root fractures
Replacement resorption (ankylosis)
Very short roots
Marginal periodontal breakdown
Vital pulps (in context of apexification; these cases may be directed toward Vital Pulp Therapy instead)
Vital Pulp Therapy indications include Apexogenesis, Pulp Capping, and Pulpotomy when the tooth is a candidate for continued root development
Apexification with Calcium Hydroxide (Ca(OH)₂)
Three general phases
Access
Instrumentation
Placement of Ca(OH)₂ intracanal dressing and periodic replacement
Dressing frequency
Every 3−6extmonths until an apical bone barrier has developed
Definition emphasis
Induction of apical calcific barrier (bone) in immature teeth with incomplete root formation when the pulp is necrotic (non-vital)
Process description
Thorough chemomechanical debridement of the root canal space
Placement of Ca(OH)₂ paste as an intracanal dressing
Apexification with Calcium Hydroxide: Treatment Evaluation & Prognosis
Treatment evaluation schedule
First recall: 4−6extweeks; radiographic evaluation; indications for tooth re-entry
Then recall in 3−6extmonths thereafter
If apex is still open, replace Ca(OH)₂ and re-enter after another 3−6extmonths
If calcific barrier forms, proceed with obturation
Long-term follow-up
At 1extyear follow-up, evaluate radiographically for resolution/bony fill of periapical radiolucency and proceed with obturation
Prognosis
Generally good success rate
Very immature teeth with thin dentin walls are at high risk of root fracture
Incidence of root fracture depends on the stage of root development
Barrier formation occurs more rapidly when the apical opening diameter is less wide
Outcome assessment criteria (for apexification via Ca(OH)₂)
Absence of signs or symptoms of pulpal and/or periapical disease
Presence of calcific barrier across the apex as demonstrated by radiographs and tactile probing with a file upon re-entry
Determinants of failed treatment
Primary cause: bacterial contamination
Common source: loss of coronal seal or inadequate debridement
Apexification with Mineral Trioxide Aggregate (MTA)
Rationale
Create an instant apical barrier with a biocompatible material (bioceramics like MTA)
Three general phases
Access
Instrumentation
Placement of Ca(OH)₂ for disinfection, followed by placement of MTA across the open apex to create an instant apical barrier
apical barrier creation
Artificial barrier across open apex in teeth with immature root formation using bioceramics (e.g., MTA)
Process steps for MTA apexification
Local anesthesia and rubber dam isolation
Conventional access with a high-speed burr for canal debridement
Place Ca(OH)₂ paste for one week to disinfect the canal system
Mix MTA with sterile water and carry into the canal
Condense MTA to the apical extent to create a 3−4extmm barrier
Verify MTA placement radiographically; if unsatisfactory, rinse and repeat
Place a moist cotton pellet in the canal to ensure proper MTA setting
Clinical practice notes
MTA-based apexification tends to shorten treatment time compared to long-term Ca(OH)₂ therapy
Clinical examples
Demonstrated in cases presented by colleagues (e.g., Drs. Berrios, Brennan) in the course materials
Comparison: Ca(OH)₂ Apexification vs MTA Apical Barrier
Clinical outcomes
Similar clinical success rates for both approaches
Advantages of MTA apexification
Reduced treatment time
More predictable apical barrier formation
Regenerative Endodontics and Current Trends
Current trends (as of 2026)
Pulpal tissue engineering
Stem cell research
Regenerative endodontics
Questioning whether apexification will become obsolete with regenerative approaches
Paradigm shifts in managing immature teeth with periradicular disease
Shifting from apexification to apexogenesis where feasible
Key literature pointers
Ling-Huey Chueh & George T-J Huang (regenerative approach in immature teeth with periradicular periodontitis or abscess)
Vital Pulp Therapy indications include Apexogenesis, Pulp Capping, Pulpotomy
Apexification indications include Root-end Closure when apex is open and pulp necrosis
Regenerative procedures considered when aiming for continued root development in immature teeth with necrotic/pulpally involved tissue
Diagnostic considerations influence case selection (see below)
Case Selection Decision Tree for Incompletely Formed Roots
Decision pathways (summary from the slide/tree)
Irreversible Pulpitis / Necrotic Pulp
Closed apex → Root canal therapy
Open apex → Vital Pulp Therapy (Pulp Capping or Pulpotomy) or Root-end Closure with Ca(OH)₂ or MTA or Regenerative Endodontics
Reversible Pulpitis
Vital Pulp Therapy (Pulp Capping or Pulpotomy)
Cases with open/apical conditions may consider Regenerative Endodontics or RCT with obturation depending on diagnosis and vitality
Emphasis in decision-making
Always weigh tooth restorability, microbial control, and potential for continued tooth development
Diagnostic Considerations and Terminology: Pulpal Disease
Diagnostic problem
The term “irreversible pulpitis” implies an outcome of pulp extirpation; however, modern evidence shows potential for Vital Pulp Therapy in some cases labeled as irreversible pulpitis
Evidence base
Systematic review (Cushley et al., J Dent 2019) shows similar success rates for Vital Pulp Therapy (VPT) and non-surgical root canal therapy (NSRCT) for certain irreversible pulpitis cases
Terminology evolution
Some authors suggest using a more generic term “pulpitis” to avoid implying non-viability of treatment
Future trends in diagnosis
The nomenclature in pulpal and periapical disease is evolving
European Society of Endodontology (ESE) S3-level guidelines advocate precise terminology and outcome-focused diagnostics
Practical implications
An accurate diagnostic terminology and appreciation of core outcomes improve treatment planning and success rates
Case Selection, Outcome, and Follow-Up: What Counts as Success or Failure
Criteria for success (apexification with Ca(OH)₂ or MTA)
Absence of signs or symptoms of pulpal and/or periapical disease
Presence (or radiographic evidence) of a calcific barrier across the apex
Confirmed by radiographs and tactile probing on re-entry if needed
Criteria for failure
Persistent symptoms, persistent radiolucency, lack of barrier formation, or failure of the apical barrier
Follow-up considerations
Regular recalls to monitor healing, barrier formation, and restoration integrity
Practical Considerations and Clinical Examples
Importance of coronal seal integrity
Loss of coronal seal is a common source of bacterial contamination leading to treatment failure
Coronal restoration and prevention of microleakage
Timely and durable coronal restoration following apexification or regenerative treatment is critical
Clinician experience and material choice
Choice between Ca(OH)₂ and MTA may depend on case specifics, anatomy, patient factors, and desired treatment duration
Current and Emerging Trends: 2024–2026 Outlook
Regenerative endodontics as a growing field
Emphasis on stem cells, signaling molecules, and scaffolds to support dentin/pulp regeneration
Pulpal tissue engineering and stem cell research
Potential to re-establish vitality and continued root formation in immature teeth with necrotic pulps
The shift away from apexification toward apexogenesis and regenerative approaches when feasible
Clinical decision-making remains nuanced
Not all cases are candidates for Regenerative Endodontics; proper case selection remains essential
Concluding Thoughts
The management of incompletely formed roots requires a nuanced approach balancing biology, mechanics, and patient-specific factors
Current trends suggest a move toward vitality-preserving and regenerative strategies, but traditional apexification with Ca(OH)₂ or MTA remains relevant and effective in appropriate cases
Ongoing refinement of diagnostic terminology and outcomes will support better, more consistent treatment planning
Appendix: Key Terms and Formulas
extCa(OH)2<br/>ightarrowextcalciumhydroxide, commonly used as an intracanal medicament for disinfection
3−6extmonths, recall interval for Ca(OH)₂ apexification dressing
4−6extweeks, initial recall after Ca(OH)₂ placement
3−4extmm, thickness of MTA apical barrier
1extyear, follow-up interval to assess healing and plan obturation
extMTA, mineral trioxide aggregate; a commonly used bioceramic for apical barriers
extBioceramics, biocompatible materials used for regenerative and barrier formation
Sources and Acknowledgments
Content adapted from Nadia Chugal’s lecture materials (Endodontics, UCLA) and related updates on apexogenesis, apexification, regenerative endodontics, and current trends in pulpal diagnosis and treatment
References cited within the course materials include reviews and guidelines on pulpal and periapical diagnosis and treatment planning