Endodontics of immature permanent teeth
1- Introduction
Immature permanent teeth have anatomical and physiological characteristics that make endodontic therapy difficult in the presence of early pulp involvement.
The treatment of these teeth depends on the stage of root formation; it must allow for root and alveolar development or the formation of an apical barrier.
2- General information on the immature permanent tooth
2-1 Definition of immature permanent tooth
A permanent tooth, present on the arch, is said to be immature as long as the cemento-dentin junction and/or the apical constriction has not yet formed.
2.2 Histo-anatomo-physiological characteristics of the immature permanent tooth
2-2-1 At the coronary level:
– Pronounced cusps + Deep and anfractious furrows.
-The enamel is very thin, porous, rough, irregular on the surface.
– Dentin has a fragile, thin and poorly mineralized structure.
-The dentin tubules are widely open.
-The pulp volume is very important
- At the root level:
-absence of root edification → absence of JCD
-the apex is wide open
-the root canal is wide
-The dental walls are thin and fragile
2.3 Stages of root development according to Nolla (1960):
3- Biomaterials used in endodontic treatments for PID:
3-1 Calcium hydroxide: is obtained by mixing quicklime (CaO) and water
- Properties :
– pH of approximately 12.5
– low thermal conductivity.
– Compressive strength is very low.
– Weakly radiopaque. Its radiopacity is close to that of dentin
– Poor adhesion to dentin and poor sealing capacity
– tendency to dissolve over time and disappear after 6 months,
– It is a biocompatible material.
-Anti-inflammatory, hemostatic and antimicrobial action
3-2 MTA (Mineral Trioxide Aggregate) : MTA comes in the form of a gray or white powder, packaged in pre-measured sachets.
- Properties :
– Very alkaline pH 10.2 immediately after mixing, then gradually increases to 12.5 after 3 hours
– Radiopacity is greater than that of dentin (0.7 mm)
-Not sensitive to humidity :
– the MTA presents a good marginal adaptation to the dental walls,
-Anti-inflammatory effect in vivo, which promotes the formation of a dentin bridge
– Antimicrobial action in aqueous environments linked to its high pH.
3-3 Biodentine: comes in the form of a powder based on tricalcium silicate and an aqueous solution of calcium chloride and excipients.
- Properties:
-Low porosity of Biodentine® explains its superior mechanical properties.
– Radiopacity : Biodentine® contains zirconium oxide which gives it a radiopacity equivalent to a thickness of 3.5 mm of aluminum
– excellent sealing capacity observed at the dentin level
4-Endodontic therapies for immature permanent teeth
4-1 Therapeutics on living teeth allowing apexogenesis
4-1-1 Definition of apexogenesis
It is the development and physiological formation of the root end of a living tooth treated in the event of pulp exposure, by capping or vital pulpotomy.
4-1-2 Techniques
- Juxta-pulp capping (indirect pulp; natural Bonsack):
- Definition: This is an intervention which consists of placing on a cover of decalcified dentin supposed to be in contact with the pulp and deliberately left in place a substance capable of allowing dentin apposition.
- Directions:
-Rapidly progressing penetrating caries.
-Deep caries with chronic closed pulpitis.
-primary acute pulpitis.
– Pulp hyperemia.
- Contraindications:
-Non-reversible total pulpitis.
-Chronic ulcerative or hyperplastic pulpitis.
-Retro pulpit.
-Penetrating caries bathed in saliva.
-General illnesses with major infectious risk
4-1-2-2 direct styling:
- Definition: It is an intervention which consists of placing on a denuded dental pulp a substance capable of allowing its healing and the dentin closure of the pulp chamber and also ensures its root edification in the case of an immature tooth.
- Directions:
-Minimal pulp exposure (<1mm) and recent : less than 24 hours.
-Iatrogenic pulp exposure
-Limited coronary decay.
- Contraindications:
*General: patients at risk of infection / Contraindications to anesthetics / poor oral hygiene
*Local:
-presence of signs of pulpitis,
-significant coronary deterioration,
-very significant pulp exposure;
-relatively long pulp exposure time more than 24 hours.
- Surgical technique:
-Control of pulp vitality
– Preoperative X-ray
– Local or locoregional anesthesia without vasoconstrictor
– Laying the dike.
– In case of caries: Careful dentin curettage.
-Washing the pulp wound with physiological serum.
-Slight widening of the pulp opening to create a means of retention and stabilization of the capping material.
-Hemostasis using dry, sterile cotton or cotton soaked in hydrogen peroxide.
-Installation of the styling product (calcium hydroxide, MTA, biodentine, etc.)
-X-ray control
-Implementation of the final restoration
4-1-2-3 Partial Pulpotomy
- Definition: This is an intervention which consists of performing a section of the cameral pulp at a given level, eliminating the amputated part, and placing a substance in contact with the remaining living pulp stump to allow healing.
- Directions:
-Minimal pulp exposure.
-If the time lapse does not exceed 48 hours between the time of the trauma and the consultation.
- Contraindications
-General: patients at risk,
-Local: pulp inflammation, onset of necrosis, significant coronal deterioration and pulp exposure time greater than one week after trauma.
- Operating protocol:
-Preoperative X-ray.
-Local anesthesia without vasoconstrictor.
-Laying the surgical field.
-The pulp wound and dentin are cleansed with 0.5% chlorhexidine.
-Amputation of the pulp to a height of 2 mm with a sterile, cylindrical diamond bur, mounted on a turbine and without spray.
-Bleeding control.
-Washing the wound with sterile physiological serum (to eliminate the clot).
– Drying using large sterile paper points mounted upside down.
-Capping of the pulp tissue with calcium hydroxide or MTA or Biodentine® without applying compression.
-Creation of a waterproof reconstruction in the same session.
-Postoperative clinical and radiographic follow-up.
4-1-2-4 Cervical Pulpotomy
- Definition : It consists of the total removal of the cameral pulp.
- Indications
Immature living tooth, with significant exposure and the time between the time of trauma and consultation is greater than 3 days.
The pulp tissue at the site of exposure is necrotic and the vascular network is disrupted.
- Contraindications
General: patient at risk.
Local : pulp necrosis
- Surgical technique:
– Anesthesia without vasoconstrictor.
– Placement of the surgical field.
– Amputation of the cameral pulp using a large sterile round bur with a long steel neck mounted on a contra-angle
– Checking hemostasis.
– Rinse with sterile physiological serum.
– Application of the styling product without compression
– Installation of an MRI or glass ionomer.
– Reconstruction.
– Postoperative clinical and radiographic checks until root closure
4-2 Therapy on necrotic tooth inducing apexification:
4-2-1. 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 osteocement or comparable tissue.
4-2-2. Indication:
-Contraindications or failures of apexogenesis techniques.
-The stage of development of the tooth corresponds or not to the age of the patient:
– Immature teeth with necrotic pulp, with or without periapical lesions.
4-2-3 Techniques:
4-2-3-1 Apexification with Ca(OH) 2 :
- Principle: Calcium hydroxide placed in the canal is able to dissociate into calcium and hydroxyl ions which will diffuse into the periapical tissues and create an environment favorable to tissue repair
- “Omnibus” technique: closure of the root end by formation of calcified tissue
Indication: in all cases, whether the stage of development of the tooth is in accordance with the patient’s age or not
- Heithersay technique (soft): the placement of an anatomical root apex, made of dentine covered with cementum,
Indication: In case there is a concordance between the stage of development of the tooth and the age of the patient.
- Operating protocol
(a, b) Access cavity,
(c)Minimal instrumentation with 2.5% sodium hypochlorite irrigation,
(d)Root canal drying,
(e)The placement of calcium hydroxide,
(f) Placement of a wet cotton pellet and CVI, a clinical and radiographic control after 3 months highlighted the formation of the calcified barrier (g).
- Postoperative follow-up: clinical and radiographic:
-at one week, one month, three months, six months, one year until an apical calcified barrier is obtained; renewal of Ca(OH) 2 as soon as necessary
-Permanent root canal filling when the tooth is asymptomatic and the apical barrier is visible on X-ray (6 to 18 months).
4-2-3-2 Apical plug technique with MTA or biodentine
- Principle : These materials allow for rapid and watertight sealing of the apex by creating an apical stop in a single session, thanks to their bio-inductive properties, by the formation of a mineralized tissue barrier
- Operating protocol:
(a,b): Access cavity,
(c)Minimal instrumentation with 2.5% sodium hypochlorite irrigation,
(d) Root canal drying
(e) Placement of the 4–5 mm of the MTA in the apical third of the canal,
(f)Root canal obturation with gutta-percha,
(g) Placement of the CVI and the composite
- Postoperative follow-up
A check-up appointment at 6 months
4-2-3-3 Regenerative endodontics : Revascularization
- Definition: Regenerative treatment for necrotic permanent teeth with an open apex whose root development is interrupted
- principle : is to transfix the apex using a file. This action induces the formation of a blood clot within the canal, the contents of which have previously been emptied, cleaned and disinfected
- Operating protocol:
(a,b) Endodontic access cavity
(c)Minimal instrumentation with 2.5% sodium hypochlorite irrigation,
(d): Root canal drying
(e) Placement of metronidazole (100 mg) and ciprofloxacin (100
mg) mixtures with serum inside the canal
(f) Placement of a wet cotton pellet and CVI
(g) Irrigation with 17% EDTA and physiological serum completed by canal drying
(h) Induction of bleeding by periapical transgression
(i) Blood-filled canal
(j)The placement of temporary coronal filling materials.
definitive coronal restoration
- Clinical follow-up
A check-up is carried out at 1 month post-operatively, then at 3, 6, 12, 15 and finally 24 months. Clinically, the absence of pain on palpation and percussion will be sought; and radiologically, the reduction of the apical lesion, the thickening of the root walls and the increase in the length of the root will be sought.
4-2-3-4 .New revascularization techniques
- Principle: The basic principle is that three key elements are required to achieve tissue regeneration: stem cells, growth factors and a matrix.
- PRP (Platelet Rich Plasma) membranes: is defined as a concentrate of first-generation autologous platelets rich in growth factors
- PRF (Platelet Rich Fibrin) membranes: defined as a platelet concentrate that brings together, in a single fibrin membrane, all the constituents that promote healing.
- Post-op follow-up: at 3 and 6 months then at 12, 14 and 18 months
5- Conclusion
Therapeutics for immature permanent teeth aim to preserve pulp vitality as much as possible in order to allow it to retain its physiology, which thus ensures its longevity.
If this is no longer possible, our treatments will aim to protect the tooth from possible complications that could arise after pulp destruction.
The urgent nature of pathologies of immature teeth requires rapid intervention, which is the key to the success of the treatment .
6- Bibliography:
- Direct pulp capping: histophysiological aspects, success factors and current biomaterials: Thesis defended on December 10, 2012 presented by Morgane Guyomard for obtaining the state diploma of doctor of dental surgery, University of Brittany
- Fortier JP, Demars C. “Summary of pedodontics”; Masson Edition; 1983: 116-124.
- Villette G “Revascularization of a traumatized tooth; Clinical case” Dental information n° 40-November 17, 2010.
- Pathophysiology of immature permanent teeth: Cohen Didier; Cohen Samuel. Garancière – University of Paris 7. 2009-2010.
- Apical sealing in teeth with open apices: alternative solutions to surgical treatment: M. Karami1, I. Benkirane, Z.Aljalil1, A. El Ouazzani. Journal of the Order of Dentists of Quebec Volume 44 July/August 2007.
- The notebooks of the dental internship: Apexogenesis – Apexification: E. ROY AHU Nantes, C. Fraysse PU-PH Nantes. January 2005.
- Revascularization: Laval Endodontics Clinic.2010.
- Apexification treatment with mineral trioxide aggregate. Dr. Sanaa Chala; Professor Sana RIDA. Faculty of Dentistry, Rabat
Endodontics of immature permanent teeth
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