Endodontics of temporary teeth and immature permanent teeth
Introduction :
The conservation of temporary teeth until the normal date of their loss is desirable, endodontic therapies are specific and delicate due to their histological, physiological and pathological characteristics, the difficulties of precise diagnosis and the state of the pulp and the technical and psychological constraints in children.
Reminders: physiology of the temporary tooth:
The temporary tooth has a life span determined in time, its evolution is subject to the phenomena of resorption and its purpose is to be replaced by a permanent tooth, we distinguish 03 stages:
- Stage I: training.
- Stage II: stability.
- Stage III: resorption.
Stage I: the temporary tooth in formation (immaturity):
- Root in formation.
- Physiology similar to that of the immature permanent tooth.
- Significant vascularization.
- Cellular potential.
- “repair” always possible.
- Therapeutics oriented towards the conservation of pulp vitality.
Endodontics of temporary teeth and immature permanent teeth
PATHOLOGY: – caries (rare). Trauma. REPAIR: always possible. THERAPY : preservation of vitality. |
| Summary: Stage I: Immaturity: |
Stage II: the stable temporary tooth:
- Fully formed tooth.
- Physiology comparable to that of the permanent tooth, but characteristics specific to the temporary tooth (enamel: low thickness)
Dentine: widely open tubules).
Pulp: large volume
Periodontium: presence of pulpo-periodontal communications, numerous accessory canals.
PATHOLOGY: – very rapid pulp damage. Frequent periodontal damage. REPAIR : possible. THERAPY: oriented towards tooth conservation. Summary: stage II: stability. |
Stage III: resorption of the temporary tooth:
- Changes in root structures:
- Root length;
- Apical orifice.
- Changes in paradental structures:
- Epithelial attachment;
- Interradicular bone.
- Proximity to the germ of the permanent tooth.
Endodontics of temporary teeth and immature permanent teeth
PHYSIOLOGY: oriented towards “replacement”Temporary tooth permanent tooth.Temporary periodontium permanent periodontium. PATHOLOGY: rapidly evolving and non-reversible. THERAPY: – oriented towards tooth conservation or extraction? Limited treatment indications. Summary: stage III: resorption of the temporary tooth. |
Endodontic therapies for temporary teeth:
- Pulpotomy:
- Principle:
Pulpotomy consists of the total removal of the coronal pulp followed by the application, at the orifice of the pulp canals, of a material which must have the following purpose:
- Promote healing at the amputation site, while preserving the vitality of the root pulp.
- Indications: they are of 03 orders:
- Therapeutic: this option can be chosen from the outset in deep caries, and in accidental pulp exposures, either during treatments or by coronal fracture. (any break-in or pulp damage, in the absence of pulp pathology, can be treated by pulpotomy when the temporary tooth is in stages II and III.)
- Preventive : in subjects at high risk of caries, with little motivation, for example if the systematic use of pedodontic caps has been planned.
- Mechanical: when coronal destruction requires the search for anchoring of the reconstitution material in a part of the pulp chamber, a pedodontic cap must be placed in this case.
- Contraindications:
- Radicular pulp inflammation, which can be verified by the quality, intensity and duration of the hemorrhage after excision of the cameral pulp.
- The tooth can be permanently restored (not too much loss of substance).
- spontaneous pain.
- internal resorption or pulp calcification.
- Presence of furcation pathology, or fistulated or non-fistulated abscess.
- Surgical technique:
- Initial X-ray, imperative.
- Local anesthesia.
- Laying the surgical field
- Careful curettage + disinfection of the cavity.
- The endodontic access cavity
- The eviction of the cameral pulp.
- Rinsing the cavity with physiological serum.
- Hemostasis with a cotton ball soaked in physiological serum compressed in the chamber for 3 to 5 minutes.
- Application of styling product (well-condensed pure calcium hydroxide with absorption of moisture with a sterile cotton ball).
- Waterproof coronal restoration (watertightness of the restoration is considered an important factor for success).
- Control: monitoring and periodic reassessment of pulpotomies are imperative, based on clinical and radiographic criteria.
- Pulpectomy:
- Principle: This is the most complete removal possible of the pulp parenchyma in the pulp chamber and root canals, followed by shaping and filling of the canal as completely as possible given the morphological characteristics of the canals, roots and apices.
- It is more difficult to achieve on temporary teeth:
- The canal morphology can be extremely varied and make the total extirpation of the root pulp random.
- Physiological resorption modifies the root structures, the limits of which become difficult to define.
- Any endodontic maneuver must take into account the underlying definitive germ.
Endodontics of temporary teeth and immature permanent teeth
- Indications and contraindications:
On teeth with vital pulp, pulpectomies will only be performed in cases where pulpotomy has failed.
In stage I, the indications for pulpotomy will be pushed to their limit, while in stage II, pulpectomy can be more easily performed.
In stage III, pulpectomy will only be attempted if rhizalysis affects less than half of the root width.
- Operating protocol:
- Preoperative X-ray.
- Local anesthesia with vasoconstrictor.
- Dentin curettage and cavity cleaning.
- Endodontic access cavity.
- Eviction of the cameral parenchyma and identification of the number and location of the canal orifices.
- Approximate assessment of working length : root length from which 2mm is removed at stages I and II, 4mm at stage III.
- Catheterization with a K file no. 10.
- Root canal reaming + root canal irrigation with sodium hypochlorite.
- Root canal drying is performed with absorbent paper tips.
- Root canal obturation performed only with paste: zinc oxide eugenol (never gutta cone), (the use of calcium hydroxide seems more acceptable with regard to the biological aspect, the disadvantage of this material is that it is too resorbable).
- Obturation of the pulp chamber with an accelerated setting zinc oxide eugenol cement, zinc orthophosphate, carboxylate or glass ionomer.
- Filling the tooth with silver amalgam, composite or a preformed pedodontic cap.
B) Pulp therapies for immature permanent teeth:
1. Apexogenesis: the immature permanent tooth with living pulp:
- Definition: It is the physiological development and formation of the root end after pulp exposure of an incompletely formed tooth, in which the pulp is alive.
(Andreassen 1990)
- Goals:
- Maintain pulp vitality
- Induce the formation of a dentin bridge
- Allow the pulp, which is neither infected nor inflamed, to continue building the root and apical closure by placing the apical JCD.
- 03 techniques are possible: (direct pulp capping, partial pulpotomy and cervical pulpotomy)
- Direct pulp capping:
- Definition: is an intervention which consists of placing on the exposed dental pulp a substance capable of allowing its healing and the closure of the pulp chamber and also the root formation.
Endodontics of temporary teeth and immature permanent teeth
- Indications:
Minor pulp exposure (accidental denudation of the pulp following an iatrogenic dental procedure during curettage or poorly conducted cavity cutting, denudation following a penetrating fracture).
- Operating protocol:
- Anesthesia
- Setting up the operating field
- Cleaning the pulp wound: sterile physiological serum.
- Hemostasis
- Styling itself: the application of calcium hydroxide or MTA.
- Coronary reconstruction: it must be watertight.
- Post-operative clinical and radiographic follow-up: pulp vitality tests and radiographic checks must be carried out: 1st check : one week later
2nd check – up: 4 weeks (the presence of a dentin bridge can be seen).
Regular checks every 3 months for a period of 1 to 3 years until the JCD is implemented.
- Pulpotomy (partial or cervical):
- Definition: is an intervention which consists of performing at a chosen level, the section of the living cameral pulp, to eliminate the amputated part and to place in contact with the remaining pulp stump(s) a substance capable of allowing at this level its healing and the dentinal closure of the canal orifice(s).
- Indications:
- More extensive pulp exposure.
- Exposure time greater than 24 hours but not exceeding 48 hours for partial pulpotomy.
- Extensive pulp exposure and a time period exceeding 3 days for cervical pulpotomy.
- Operating protocol:
- Preliminary radio.
- Anesthesia with vasoconstrictor.
- Laying the surgical field.
- Cleaning the tooth and pulp wound.
- Amputation of the pulp (partial or cervical depending on the case). The amputation is performed under continuous irrigation of sterile physiological serum
- Hemostasis
- Washing the wound (cotton ball + physiological serum).
- Setting up the styling product
- Watertight coronal reconstruction.
Endodontics of temporary teeth and immature permanent teeth
- Post-operative follow-up:
- Clinically the tests must be positive.
- The calcified bridge re-isolating the pulp should be visible from the 4th week .
- Note: as soon as stage 10 is reached, a pulpectomy must be performed followed by canal obturation if not; risk of dystrophic calcification.
2. Apexification: immature permanent tooth with mortified pulp.
- Definition:
It is the induction of apical closure, or resumption of development, of an immature tooth whose pulp is no longer alive, by the formation of osteo-cementum or a comparable tissue. (Breillat 1973).
- Goals:
- Apical closure without root elongation.
- Apical closure with root elongation when the cells of the Hertwig sheath remain alive.
- Surgical technique:
- Calcium Hydroxide Apexification Technique:
- Operating field
- Endodontic access cavity
- Mechanical trimming (pins + files) + chemical trimming with sodium hypochlorite.
- Radiographic determination of working length/at shortest wall.
- Drying the canal
- Filling the canal with calcium hydroxide.
- X-ray control.
- Provisional coronary reconstruction (CVI).
- Post-operative clinical and radiographic follow-up.
After 6 to 18 months an apical barrier can be obtained.
- Permanent root canal filling.
- Final restoration.
- Apexification with MTA: MTA is used to create an apical plug on teeth with necrotic pulp and an open apex.
- Operating protocol:
- Setting up the operating field.
- Adequate endodontic access cavity
- Root canal debridement + CLONa irrigation
- Drying the canal
- An apical plug with 3 to 4 mm MTA is created and controlled radiographically
- Placing a damp cotton ball in the canal
- Temporary coronal obturation 3 to 4 hours
- Subsequently, perform a canal obturation with gutta for the remaining part.
- Final restoration.
Revascularization of the immature permanent tooth:
- An alternative to Ca(OH)2 and MTA Apexification has gradually emerged, with the aim of ensuring the sustainability of the dental organ with stimulation of the root building process. It is based on the recruitment of stem cells, by induction of an intra-canal blood clot and then its capping.
- This technique is based on tissue engineering and shows very good clinical results. It is called revascularization.
Definitions:
Several definitions can be associated with revascularization:
1. Root canal revascularization can be defined as a relatively new technique that refers to a regenerative procedure for the treatment of necrotic permanent teeth with open apices.
2. Revascularization is also defined as “the procedure to restore vitality to a non-vital tooth to allow tissue repair and regeneration.”
Principles:
- Pulp revascularization is based on 3 principles:
1. Disinfection of the canal space without instrumentation.
2. Create a matrix-friendly environment to promote tissue growth.
3. Temporary restoration sealed against bacteria to prevent reinfection of the root canal space.
1st visit:
1. Root canal disinfection: a fundamental and mandatory step to achieve treatment success, unlike conventional endodontics, root instrumentation is contraindicated because the root walls are thin and immature. The antimicrobial agents used are either triple antibiotic paste (ciprofloxacin, metronidazole and minocycline) or Ca(OH)2
2. The irrigant used is 1.5% sodium hypochlorite.
2nd visit:
1. Ask the patient if he or she has signs and symptoms of persistent infection, (repeat disinfection)
2. Local anesthesia without vasoconstrictor.
3. Irrigate with 20 ml of EDTA 17%.
4. Dry with paper towels.
5. Create bleeding in the canal by over-instrumenting 2mm beyond the apical foramen.
6. Placed a resorbable matrix such as COLLA plug MC over the blood clot as well as the MTA.
7. Tooth restoration (glass ionomer, composite or amalgam)
CONCLUSION:
Current pediatric dentistry is fully equipped to offer our children mouths that are practically free of carious lesions with harmoniously implanted teeth.