Microscope-Assisted Endodontic Treatment and Biomimetic Direct Composite Restoration of a Mandibular Third Molar
Abstract
Endodontic treatment of mandibular third molars is often considered controversial due to complex anatomy, limited access, and questionable restorability. However, when strategic value exists, modern endodontic techniques combined with biomimetic direct composite restoration allow predictable tooth preservation. This article presents a step-by-step workflow for root canal treatment of a mandibular wisdom tooth followed by immediate adhesive composite restoration under rubber dam isolation.
Clinical Background
Mandibular third molars may serve as functional teeth, abutments, or space maintainers. Extraction is not always the optimal choice, especially when the tooth is restorable and periodontal conditions are favorable. The primary challenges include:
- Limited access and visibility
- Complex root canal morphology
- Deep carious lesions close to the pulp
- Risk of coronal leakage post-endo
A protocol-based approach addressing both endo and coronal seal is essential for long-term success.
Step-by-Step Clinical Protocol
1. Pre-operative Assessment
Clinical examination and radiographic analysis revealed:
- Deep occlusal caries with pulpal involvement
- Fully erupted mandibular third molar
- Favorable root morphology without severe curvature
- No vertical root fracture or advanced periodontal breakdown
Treatment plan: single-visit endodontic therapy followed by direct composite restoration.
2. Rubber Dam Isolation
Absolute isolation was achieved using a rubber dam with modified clamp placement adapted for posterior access.
Why it matters in wisdom teeth:
- Prevents salivary contamination
- Improves patient safety
- Enhances visibility in difficult anatomy
Rubber dam isolation is non-negotiable for both endodontic and adhesive procedures.
3. Caries Removal and Access Cavity Preparation
- All infected dentin was removed peripherally
- Access cavity prepared conservatively, respecting pericervical dentin
- Unsupported enamel eliminated
- Access refined to improve straight-line canal entry
Principle: conserve tooth structure while ensuring adequate endodontic access.
4. Canal Identification and Negotiation
Using magnification and ultrasonic refinement:
- Canal orifices were identified
- Calcifications were managed conservatively
- Glide path established using small stainless-steel hand files
Mandibular third molars often present with fused roots or irregular canal anatomy, requiring patience and tactile control.
5. Working Length Determination
Working length was established using:
- Electronic apex locator
- Radiographic verification
This dual confirmation reduces procedural errors and enhances apical control.
6. Cleaning and Shaping
- Rotary NiTi instrumentation used following a crown-down approach
- Copious irrigation with sodium hypochlorite
- Gentle activation to enhance debridement
The objective was effective cleaning while minimizing dentin removal.
7. Obturation
Canals were obturated using:
- Matched-taper gutta-percha
- Bioceramic or resin-based sealer
Obturation quality was confirmed radiographically, ensuring dense fill and apical seal.
8. Immediate Coronal Seal
Immediately after obturation:
- Gutta-percha was cut back below the canal orifice
- Orifices sealed to prevent coronal microleakage
Immediate coronal sealing is critical to endodontic success.
9. Cavity Refinement for Composite Restoration
- Access cavity margins refined
- Internal line angles rounded
- No mechanical retention added
The cavity design followed adhesive principles rather than traditional extension.
10. Adhesive Protocol
A universal or two-step self-etch adhesive system was applied:
- Active application on dentin
- Controlled air thinning
- Adequate light curing
Immediate dentin sealing improves bond strength and reduces post-operative sensitivity.
11. Composite Restoration
A layered composite technique was used:
- Dentin replacement using bulk-controlled or fiber-reinforced composite where indicated
- Enamel layers placed separately to reproduce occlusal anatomy
- Incremental curing to minimize shrinkage stress
This approach restores both function and structural integrity.
12. Finishing and Polishing
- Occlusion adjusted carefully
- Margins refined
- Final polish performed to reduce plaque retention
Proper finishing enhances longevity and patient comfort.
13. Post-operative Evaluation
Final radiographs confirmed:
- Adequate obturation
- Intact coronal seal
- Absence of voids
Clinically, the tooth demonstrated proper occlusion and marginal adaptation.
Discussion
Successful endodontic treatment of mandibular third molars depends on strict case selection, magnification, and adherence to protocol. However, endodontic success alone is insufficient without a durable coronal seal. Biomimetic direct composite restoration allows immediate reinforcement of the remaining tooth structure while preserving future treatment options.
Avoiding premature extraction aligns with conservative dentistry principles when anatomy and restorability permit.
Conclusion
Mandibular wisdom teeth can be predictably treated endodontically and restored using direct composite when modern techniques and biomimetic principles are applied. A protocol-driven approach combining precise endodontics with immediate adhesive restoration ensures functional preservation and long-term success.
References
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- Van Meerbeek B, et al. Adhesive dentistry fundamentals. Dent Mater. 2020.
- Ferracane JL. Resin composite stress and polymerization. Dent Mater. 2011.
- Plotino G, et al. Ultrasonics and magnification in endodontics. J Endod. 2013.
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