牙体解剖学精品课件（中山大学）12.2活髓保存与根尖诱导成形术

Chapter 18 Vital Pulp Therapy and Apexification 学习要点 熟悉：直接盖髓术、间接盖髓术、根尖诱导成形术操作步骤 了解：根尖屏障术的原理和操作步骤 Vital Pulp Therapy 活髓保存治疗疗 Direct pulp capping 直接盖髓术术 Indirect pulp capping 间间接盖髓术术 Pulpotomy 牙髓切断术术 “Principles and practice of endodontics” 1. Pulp capping 1.1 Direct pulp capping Indications: Accidental or mechanical pulp exposure (normal pulp) Cavity preparation Placement of pins Trauma Mainly for immature permanent teeth with recent (24 hr) traumatic pulp exposure or mechanical exposure during cavity preparation Should mature teeth be pulp capped? Size of exposure limited to o.5mm Contraindicated for carious tooth with pulp involvement Enamel-dentin fracture with pulpal involvement Direct pulp capping Hemostatic reagents 止血剂剂 Saline 盐水 Hydrogen peroxide 双氧水 Diluted sodium hypochlorite 次氯酸钠 Chlorhexidine 洗必泰 Pulp capping materials Calcium hydroxide Mineral trioxide aggregates (MTA) 矿化三氧化聚合物 MTA Excellent biocompatibility and hydrophilicity Induce hard tissue regeneartion Indicated for apical barrier, perforation repair, retrofilling and vital pulpal therapy Setting time: 45 hrs Procedures 1. Ca(OH)2 or MTA applied to the exposure to stimulate differentiation of new odontoblast-like cells and formation of secondary dentin 2. Temporary restoration placed over Ca(OH)2 or MTA 3. Follow-up 4. Permanent restoration 5. Pulpotomy or endodontic treatment for symptomatic tooth 1.2 Indirect pulp capping Indications Deep carious lesions No history of pulpalgia 牙髓痛 No signs of irreversible pulpitis No pulp exposure after excavation of carious dentine Pulp Capping Materials Calcium hydroxide 氢氧化钙 The most commonly-used (direct) pulp-capping material Water-based calcium hydroxide Resin-based calcium hydroxide e.g. Dycal, Timeline Zinc oxide-eugenol cement (ZOE) Only for indirect pulp capping Bactericidal effect and hermetic marginal seal Cytotoxicity: use of ZOE as a liner in deep carious lesions is still controversial Procedures 1. Remove all softened, mushy or leathery dentine 2. Either ZOE or Ca(OH)2 placed on the remaining dentin to kill or suppress bacteria 3. Base 4. Temporary or permanent restoration 2. Pulpotomy Indicated for immature permanent teeth Traumatic pulp exposure Mechanical pulp exposure Carious pulp exposure Procedures Removal of all carious dentin and pulp tissue to the level of the radicular pulp Vital pulp stump capped with Ca(OH)2 Temporary restoration Follow-up Asymptomatic: permanent restoration Symptomatic: endodontic treatment Potential problems with pulpotomy as a permanent treatment Impossible to determine whether all disease tissue has been removed The remaining radicular pulp tissue may undergo mineralization Making further endodontic treatment difficult or impossible Internal resorption Conclusions The vital pulp therapies are predictable in teeth with traumatic or mechanical pulp exposure Direct pulp capping is contraindicated for teeth with carious pulp exposure -Pulpotomy might be the choice but is considered unproven When for financial or other reasons extraction is the only alternative, pulpotomy certainly should be considered for the benefit of the patient 4. Apical barrier technique 4.1 Principle Apical barrier technique Use Mineral trioxide aggregate (MTA) to form a calcified barrier at the root terminus that helps obturating the root canal system MTA Exhibits outstanding biocompatibility, antibacterial properties, hydrophilicity, sealing ability and long-term success Stimulates hard tissue formation Provides a seal against microleakage Establishes a hard apical barrier in order to obturate the root canal system MTA MTA placement can be done in fewer clinical treatment visits Calcium hydroxide typically includes multiple appointments over months and also requires potential tissue for continued tooth development MTA used to Induce an artificial barrier in open-apex cases Repair perforation Seal the retro-preparation in surgical endodontics Protect the pulp in direct pulp capping 4.2 Indication Pulpal necrosis teeth with apical periodontitis Immature teeth with open apices Fail to close the root end with long-term traditional apexification 4.3 Procedure (1) Cleaning and shaping of the root canals Coronal-radicular access to the defect to remove all necrotic pulp tissue and microbial infection Not to heavily instrument the already thin and relatively fragile walls of the root (2) Irrigation Central to the debridement of immature teeth Benefit from the antimicrobial and tissue-solvent properties of NaOCl Often with the help of ultrasonics After thorough debridement, the canal is dried and medicated with Ca(OH)2 paste (3) Placement of the MTA Wash out the Ca(OH)2 paste, dry the canal Delivered to the canal with a dedicated MTA carrier, condensed with pluggers The canal is filled incrementally with MTA An apical plug of 4-5mm thickness is usually considered optimal All excess MTA is removed from the canal walls by scrubbing with moistened paper points or brushes. A wet cotton pellet is placed in the canal to provide moisture for the setting reaction. The pellet should not be in contact with the MTA The adequacy of the apical plug is verified radiographically (4) Filling the canal system MTA requires 4-5h for setting The hard set of the MTA verified with an endodontic file or probe. The endodontic therapy is conducted as normal (Bonded resin may be used instead of GP ) If the MTA has not hardened, the canal can be recleansed and the procedure repeated before final bonded restoration. (5) Regular re-evaluation Re-evaluate the tooth