Fragment Reattachment of Tooth - MDS Notes

Definition

Indications

• Uncomplicated crown fractures (Ellis Class I and II) - enamel or enamel-dentin fractures where fragment is available
• Complicated crown fractures (Ellis Class III) - after endodontic treatment / pulp capping if fragment is available
• Immature permanent teeth where pulp vitality preservation is critical
• Patients in "accident-prone years" (children 8-12 years) as a medium-term restoration
• When fragment is intact with well-fitting margins
• Patients with emotional attachment to their natural tooth

Contraindications

• Fragment lost or unavailable
• Severely comminuted or fragmented fracture
• Fragment too small to reattach
• Crown-root fractures extending below the gingival margin
• Poor patient cooperation
• Fragment severely dehydrated with infractions (microcracks) throughout

Ellis / IADT Classification (Relevant to Reattachment)

Fragment Storage Media

Techniques of Fragment Reattachment

1. Simple (Direct) Reattachment

• No surface preparation beyond etching
• Fragment directly bonded after acid etch + bonding agent + resin cement
• Recovers approximately 28-37% of original fracture strength
• Preferred when fragment adaptation is complete (systematic review by Garcia et al. 2018)
• First described by Chosack & Eidelman (1964)

2. Enamel Bevel Technique

• A chamfer/bevel (~45°) prepared circumferentially on the external enamel of both tooth and fragment at the fracture line
• Increases adhesive surface area
• More aesthetic as composite blend is gradual
• Fracture strength recovery: ~51%

3. Internal Dentinal Groove Technique

• A groove (0.5-1 mm wide, 1 mm deep) prepared within the dentin of both the tooth and fragment along or perpendicular to the fracture line
• Composite fills the groove acting as a "key"
• Highest fracture strength recovery: 64.97% - 89.2% (Srilatha et al.; Kulkarni et al. 2022)
• Preferred when maximum strength is needed

4. Overcontouring Technique (Reis et al.)

• After reattachment, composite resin is added circumferentially over the fracture line (buccal and/or lingual)
• Increases surface area of adhesive bond
• Fracture strength recovery: up to 50-80% of sound tooth
• Drawback: progressive aesthetic deterioration due to composite resin abrasion over time

5. Combined Techniques

• Buccal chamfer + Lingual overcontour (Stellini et al.)
• Labial double chamfer + Lingual overcontour: 54.49% strength recovery (Kulkarni et al. 2022)
• Internal groove + External bevel: synergistic increase in bond strength
• Provides at least 50% fracture resistance of the whole tooth

Comparative Fracture Strength Recovery (Kulkarni et al. 2022)

Step-by-Step Clinical Procedure

Pre-operative Assessment

1. Clinical and radiographic examination
2. Sensibility testing (pulp vitality)
3. Check for root fracture, displacement, mobility
4. Assess fragment - fit, margins, presence of cracks

Fragment Preparation

1. Store fragment in appropriate medium (milk, saline) if dehydrated
2. Clean fragment with 2% chlorhexidine solution
3. Rehydrate if stored dry (minimum 30 minutes to 24 hours in moist medium)
4. Remove any thin layer of tissue/debris from fracture surface

Tooth Preparation

1. Evaluate pulp exposure:
   • No exposure: proceed directly
   • Near-exposure: apply calcium hydroxide (Ca(OH)₂) liner over dentin
   • Pulp exposure: perform direct pulp cap / RCT as indicated
2. Apply Ca(OH)₂ over exposed dentinal tubules if needed
3. Prepare surface as per chosen technique (bevel/groove)

Adhesive Procedure (Total-Etch Technique - preferred)

1. Isolate with rubber dam
2. Etch tooth and fragment with 37% phosphoric acid for 15 seconds on enamel, 10-15 seconds on dentin
3. Rinse for 5 seconds; gently air dry (avoid desiccation)
4. Apply bonding agent to both surfaces; gently air thin
5. Light cure bonding agent (10 seconds)
6. Apply thin layer of flowable composite or resin cement to fracture surface of tooth or fragment
7. Seat fragment accurately - align carefully, apply slight pressure
8. Remove excess cement immediately
9. Light cure - note: may need to cure through enamel if using light-cured resin
10. Finish and polish fracture line

Self-Etch / Universal Adhesive Alternative

• Selective etch on enamel only
• Apply universal adhesive in self-etch mode to dentin
• Fewer steps; reduced post-operative sensitivity

Materials Used

Advantages of Fragment Reattachment

1. Preservation of natural tooth color, translucency, and surface texture - superior aesthetics to composite restoration
2. Biologically conservative - minimal tooth structure loss
3. Single-appointment procedure - less time-consuming
4. Natural incisal edge wear resistance matching adjacent teeth
5. Immediate positive emotional response from patient
6. Preserves future treatment alternatives (veneer, crown can still be done later)
7. 50-60% fracture strength acts as a "protection factor" or "shock absorber" - dissipating traumatic forces at the bond interface rather than at pulpal/periodontal structures
8. Low cost

Disadvantages / Limitations

1. Fragment must be available and intact
2. Bond strength is 28-89% of natural tooth (never 100%)
3. Risk of debonding (especially with simple reattachment)
4. Color change / discoloration of fragment over time
5. Overcontouring may cause progressive aesthetic deterioration
6. Fragment may become brittle if severely dehydrated
7. Requires skill for fragment alignment

Factors Affecting Bond Strength / Longevity

1. Storage medium - dry storage greatly reduces bond strength
2. Reattachment technique - groove > overcontour > bevel > simple
3. Adhesive material type - total-etch generally stronger; dual-cure resin cements may outperform light-cure through thick enamel
4. Fragment condition - cracks, infractions, dehydration reduce fit
5. Time elapsed - longer dry time = weaker bond
6. Pulp status - necrotic teeth show altered dentin permeability

Complications and Follow-Up

Key Examiner Points (MDS Viva)

• First case report: Chosack & Eidelman, 1964 (J Dent Child)
• "Accident-prone years": 8-12 years; fragment reattachment as "provisional restoration" during this period
• Best storage medium: Milk (or tender coconut water)
• Highest fracture strength technique: Internal dentinal groove (up to 89.2% recovery)
• Simple reattachment: Preferred when fragment adaptation is complete (Garcia et al. systematic review, 2018)
• 50-60% bond strength is actually beneficial - acts as shock absorber
• Total-etch is preferred for depth of cure through enamel in this technique
• IADT classification: Use alongside Ellis for comprehensive case description
• The procedure is described as "provisional" but can serve as definitive in many cases with good longevity

• Reattachment of Fractured Tooth: A Comprehensive Review - Cureus/PMC (2024)
• Garcia et al., Dent Traumatol 2018 - systematic review of fragment reattachment techniques
• Fragment Reattachment of Immature Permanent Incisors, J Pediatr Dent 2022
• Tintinalli's Emergency Medicine - IADT Dental Fracture Classification