Jeena Sara Paul 11th March 2009 Ist year MDS 9.00 AM Christian Dental College Ludhiana
Young permanent teeth are those recently erupted teeth in which normal physiological apical root closure has not occurred. Normal physiological root closure of permanent teeth may take 2-3 years after eruption. Young permanent teeth are in developmental stage in children from 6 years of age until mid-teens Human tooth with immature apex is a developing organ. The proliferation and differentiation of various cells are activated especially in the apical region of the young tooth to make it complete .
Developing teeth are essential for development and growth of alveolar process and periodontal ligament: D Vincent Provenza, Journal of Oral Histology inheritance and development Human tooth with immature apex is a precious tissue source for the research of human adult stem cell: Shigehiro Abe et al, Oral Science International Journal, May 2007 Young permanent teeth possesses a greater potential to rebuild the host pulp tissue and continue root maturation: Granhoss et al, Journal of dental research, 2002 A population of mesenchymal stem cells (MSCs) residing in the apical papilla of incompletely developed teeth, termed stem cells from the apical papilla (SCAP), can differentiate into odontoblast-like cells and produce dentin-like tissue in both in vitro and in vivo study systems: Huang G, Journal of Dentistry, 2008
Auto transplantation of immature teeth have high success rate of survival: Wim Laurey et al, American Journal of Dentofacial Orthopaedics Measurement of open apices of teeth can be used to assess chronological age: Camaerirrice, International Journal of forensic science
YOUNG PERMANENT TEETH MATURE TEETH Surfaces of recently erupted teeth There is generalised loss and are covered by pronounced flattening of perikymata enamel rods and perikymata No attrition present, Mammelons Attrition or wear of occlusal clearly visible surfaces and proximal contacts as a result of mastication, Mammelons absent Surface of enamel work like a semi Localised increase of elements permeable membrane; slow such as nitrogen and fluorine is passage of water from found in superficial layer of enamel of older teeth; enamel surrounding and substances becomes less permeable with having small molecular size to advancing age pass through pores.
YOUNG PERMANENT TEETH MATURE TEETH Primary dentine is present Secondary dentine present. which is composed of mantle Sclerotic and reparative and circumpulpal dentine dentine may also be present Young pulp has high number of undifferentiated Decreased number of mesenchymal cells undifferentiated cells in the• High cellular content pulp• High vascularity • Low vascularity• Low calcium and phosphorus • High calcium and phosphorus content content
Significantly greater proportion of fully erupted teeth are plaque free compared to partially erupted teeth Fully erupted teeth yielded greater number and proportion of Streptococcus mutans. Partially erupted teeth yielded Actinomyces israeli Significantly greater numbers and proportions of S salivarius were isolated from partially erupted teeth with white spot as compared with greater number of S mutans in fully erupted teeth with white spots
Caufield et al demonstrated a window of infectivity from 7-31 months when the child is at higher risk Krass et al, 1967 and Edrman et al, 1975 reported that a 2-6 year of age the child is less susceptible to acquiring MS. The second window of infectivity is present in the young permanent dentition between 6-12 years of age (Klock and Kroske, 1977). Davey and Rogers, 1984, reported that children acquire additional strains of MS as they get older and new teeth erupt.
Evaluation of pulp vitality is an important diagnostic aspect of treating young permanent teeth. The methods mainly used are thermal and electrical testing which test the vitality based on the neural response of the pulp. Immature permanent teeth are not fully innervated with alpha- myelinated axons: the neural components responsible for the pulpal pain response. This reduced number of pain receptors make them less responsive to stimuli giving FALSE NEGATIVE results from thermal and electric pulp testing. Hence the need for using methods that test the circulation of the pulp including laser Doppler flowmetry, pulsoximetry, dual wave spectrophotometry and plethysmography.
A smooth exchange from the primary to permanent dentition is of utmost importance. Ectopic eruption of permanent teeth may cause disturbance in occlusion As the permanent incisors erupt, the arch width increases slightly, the permanent incisor tips mesially and the primary cuspids move distally First molar eruption: In majority of children, the first permanent molars erupt prior to the central incisors. The first molar is guided into occlusion by the distal surface of the 2nd primary molar Incisor eruption: The mandibular central incisors are the first to erupt and maxillary laterals the last. Second molar eruption: The mandibular 2nd molar erupts before the maxillary 2nd molar; if otherwise, it can lead to Class II malocclusion.
Young permanent teeth are more sensitive to dental caries than teeth that have remained free from caries for a few years after eruption. Hence the need for preventive procedures. These include:• Pit and fissure sealants• Preventive Resin Restoration
Sealants are safe and painless way of protecting young permanent teeth from decay. “A sealant is a protective, plastic coating applied to the occlusal surfaces of the posterior teeth. The sealant forms a hard shield that keeps food and bacteria from getting into the tiny grooves in the teeth and causing decay.’’ Sealants are often applied as soon as the permanent teeth start to come through. Permanent molars have deeper grooves and more than 80-90% of caries begin here. These natural valleys are harder to clean and the enamel within the grooves are thinner
The PRR is a conservative occlusal restoration that involves replacement of discrete areas of carious structure with composite followed by application of an overlying fissure sealant. The resin used in the procedure can be filled or unfilled.
Interim restorations of a broken down or traumatised tooth until construction of a permanent restoration can be carried out or the eventual orthodontic status is established. Teeth with developmental defects- The crowns are beneficial for restoring the occlusion and reducing any sensitivity caused by enamel and dentin dysplasias in young patients. Restoration of a permanent molar which requires full coverage but is only partially erupted.
Numerous factors can affect the pulpal health of teeth, but the two major conditions detrimental to young permanent teeth are1. deep caries and2. traumatic injuries. These often lead to pulp necrosis and arrested tooth development of the involved immature tooth. The resulting wide-open apical foramina, canals with reverse taper (blunderbuss) and thin dentinal walls, represent major clinical concerns when an incompletely developed tooth fails to mature.
These can be of two configurations - non-blunderbuss - blunderbuss Non –blunderbuss -the walls of the canal may be parallel to slightly convergent as the canal exits the root -the apex, therefore can be broad or tapered Blunderbuss - The word ‘blunderbuss’ basically refers to an 18th century weapon with a short and wide barrel. It derives its origin from the Dutch word ‘DONDERBUS’ which means ‘thunder gun’. - The walls of the canal are divergent and flaring, more especially in the buccolingual direction - The apex is funnel shaped and typically wider than the coronal aspect of the canal.
Incomplete development: The open apex typically occurs when the pulp undergoes necrosis as a result of caries or trauma, before root growth and development are complete (i.e. during stages 1-4) An open apex can also occasionally form in a mature apex (stage 5) as a result of Extensive apical resorption due to orthodontic treatment, periapical pathosis or trauma Root end resection during periradicular surgery Over-instrumentation
According to the width of the apical foramen and the length of the root, Cvek has classified 5 stages of root development. Stage 1 Teeth with wide divergent apical opening and a root length estimated to less than half of the final root length. Stage 2 Teeth with wide divergent apical opening and a root length estimated to half of the final root length. Stage 3 Teeth with wide divergent apical opening and a root length estimated to two thirds of the final root length.
Stage 4 Teeth with wide open apical foramen and nearly completed root length. Stage 5 Teeth with closed apical foramen and completed root development.
Large open apices - convergent - parallel - divergent Thin dentinal walls - which are susceptible to fracture before, during or after treatment Frequent periapical lesions - with or without associated apical resorption Short roots - thus compromising crown-root ratio Fractures of crown - compromising aesthetics especially in the anterior region - necessitating post endodontic rehabilitation of both crown and root Discoloration in long standing cases
The main goal in the treatment of an immature tooth is to maintain a vital root forming organ, as long as possible, to allow physiological apical root formation. If this happens, the rest of the treatment is routine endodontic treatment The second important consideration in treating immature teeth is to keep the surgical procedure as superficial as possible, with minimal instrumentation to not disturb the not yet fully formed roots.
Clinical examination Carious involvement of pulp may be clinically obvious Sensitivity to explorer probing, review of radiographs and clinical excavation can confirm a suspicion that the lesion is more advanced than it appears. Traumatised teeth may show evidence of injury in many ways. With some injuries, the effect on the pulp may be neither apparent nor diagnosable initially. With severe injuries, the pulp is almost always deleteriously affected and requires immediate or subsequent treatment
Clinical Diagnostic Procedures Heat, cold and electrical pulp testing are classic tests for pulpal tests, vitality and viability. Interpretation of testing data must be cautious, because an open apex provides a significantly enlarged vascular supply but an incompletely developed nervous innervation. (Bernick,1964) In traumatised teeth esp., the reactions to pulp test should not be treated literally because the pulp is in a state of shock for many days or weeks and may register negatively to tests and then return later to normal status. Tests of mobility and percussion sensitivity should also be performed for comparison with unaffected teeth.
Radiographic Examination A diagnostically accurate periapical radiograph is essential for correct pulpal evaluation of a deeply carious or traumatised young permanent tooth. More than one view of the area of interest, each taken at a different angle , is helpful for locating subtle changes. Pathologic changes should not be confused with normal anatomy Internal resorption is possible in permanent teeth but not as common as in primary teeth. Pathologic external resorption is seen in severe disruptions of the periodontal ligament Treatment induced calcifications may be too thin to visualise radiographically
Direct Pulpal Evaluation Careful visual inspection, tactile evaluation during instrumentation, and even detection of foul odours given off by a pulp provide important clues about lesion depth and pulpal status.
A suggested outline for determining the pulpal status of cariously involved teeth in children involves the following: Visual and tactile examination of carious dentin and associatedperiodontium Radiographic examination of a. periradicular and furcation areas b. pulp canals c. periodontal space d. developing succedaneous teeth History of spontaneous unprovoked pain Pain from percussion Pain from mastication Degree of mobility Palpation of surrounding soft tissues Size, appearance, and amount of hemorrhage associated with pulp exposures
Case selection and treatment of choice for the young permanent tooth depends upon the
Teeth exhibiting signs and/or symptoms such as a history of spontaneous unprovoked toothache, a sinus tract, periodontal inflammation not resulting from gingivitis or periodontitis, excessive mobility not associated with trauma or exfoliation, furcation/apical radiolucency, or radiographic evidence of internal/external resorption have a clinical diagnosis of irreversible pulpitis or necrosis. These teeth are candidates for non-vital pulp treatment. Teeth exhibiting provoked pain of short duration—which is relieved upon the removal of the stimulus, with analgesics, or by brushing—without signs or symptoms of irreversible pulpitis, have a clinical diagnosis of reversible pulpitis and are candidates for vital pulp therapy. Teeth with a normal pulp requiring pulp therapy are treated with vital pulp procedures.
Pulp treatment modalities can be classified into 2 categories• Vital Pulp Therapy:1. Protective base2. Indirect pulp capping3. Direct pulp capping4. Pulpotomy5. Apexogenesis6. Regeneration• Non vital pulp therapy: Apexification; pulpectomy and root filling
Term coined by AAPD Recommends the placement of a protective base or a liner on the pulpal and axial walls of the cavity preparation to act as a protective barrier between the restorative material and the tooth. In deep cavities, the dentine covering the pulp is very thin and dentinal tubules are closely packed; this highly permeable dentine needs a protective base to seal the dentinal walls. In a tooth with a normal pulp, when dentin is exposed and all caries is removed during the preparation for a restoration, a protective radiopaque base may be placed between the permanent restoration and the dentin to minimize pulp injury, promote pulp tissue healing, or minimize postoperative sensitivity. A protective base is utilized to preserve the tooth’s vitality, promote pulp tissue healing and tertiary dentin formation, and minimize microleakage. Adverse post- treatment signs or symptoms such as sensitivity, pain, or swelling should not occur. Materials: glass ionomers, resin modified glass ionomer cements, dentin bonding agents
Indirect pulp treatment is a procedure performed in a tooth with a deep carious lesion adjacent to the pulp. The carious dentin near the pulp is left in place to avoid pulp tissue exposure and is covered with a biocompatible material. A radio-opaque base such as calcium hydroxide, zinc oxide and eugenol, or glass ionomer cement is placed over the remaining affected dentin to stimulate healing and repair. The tooth then is restored with a material that seals the involved tooth from microleakage.
Indirect pulp treatment is indicated in a permanent tooth with a normal pulp or reversible pulpitis when the deepest carious dentin is not removed to avoid a pulp exposure. The pulp is judged by clinical and radiographic criteria to be vital and able to heal from the carious insult. The restorative material should seal completely the involved dentin from the oral environment. The vitality of the tooth should be preserved. No post-treatment signs or symptoms such as sensitivity, pain, or swelling should be evident. There should be no radiographic evidence of internal or external root resorption or other pathologic changes. Teeth with immature roots should show continued root development and apexogenesis.
1960’s Eastman Dental Center Study 475 teeth: 75% would have resulted in pulp exposures with complete removal of carious dentin yet following treatment with IPT only 3% experienced clinical failureAAPD Annual Meeting (1999 & 2001) Researchers encouraged the group to reconsider this method of treating primary teethSensitive topic ‐ not always a clear delineation where
Rationale : Establishment of a healthy, intact pulp is desirable over partial or complete surgical removal Affected pulpal tissue, in the absence of a continued insult, is able to heal itself (3°dentin) Indications : History a. Mild discomfort from chemical and thermalstimuli b. Absence of spontaneous pain Clinical examination a. Large carious lesion b. Absence of lymphadenopathy c. Normal appearance of adjacent gingiva d. Normal color of tooth Radiographic examination a. Large carious lesion in close proximity to the pulp b. Normal lamina dura c. Normal periodontal ligament space d. No interradicular or periapical radiolucency
Contraindication History a. Sharp, penetrating pain that persists after withdrawing stimulus b. Prolonged spontaneous pain, particularly at night Clinical examination a. Excessive tooth mobility b. Parulis in the gingiva approximating the roots of the tooth c. Tooth discoloration d. Nonresponsiveness to pulp testing techniques Radiographic examination a. Large carious lesion with apparent pulp exposure b. Interrupted or broken lamina dura c. Widened periodontal ligament space d. Radiolucency at the root apices or furcation areas
Two-Appointment Technique (First Sitting). Administer local anaesthesia and isolate with a rubber dam. Establish cavity outline with a high-speed hand piece. Remove the majority of soft, necrotic, infected dentin with a large round bur in a slow-speed hand piece without exposing the pulp. Irrigate the cavity and dry with cotton pellets. Cover the remaining affected dentin with a hard-setting calcium hydroxide dressing. Fill or base the remainder of the cavity with a reinforced ZOE cement or a glass-ionomer cement to achieve a good seal. Do not disturb this sealed cavity for 6 to 8 weeks. It may be necessary to use amalgam, composite resin,or a stainless steel crown as a final restoration to maintain this seal.
Two-Appointment Technique (Second Sitting, 6 to 8 Weeks Later). If the tooth has been asymptomatic, the surrounding soft tissues are free from swelling, and the temporary filling is intact, the second step can be performed: Bitewing radiographs of the treated tooth should be assessed for the presence of reparative dentin. Carefully remove all temporary filling material, especially the calcium hydroxide dressing over the deep portions of the cavity floor. The remaining affected carious dentin should appear dehydrated and “flaky” and should be easily removed. The area around the potential exposure should appear whitish and may be soft; this is “predentin.”Do not disturb! The cavity preparation should be irrigated and gently dried. Cover the entire floor with a hard-setting calcium hydroxide dressing. A base should be placed with a reinforced ZOE or glass ionomer cement, and the tooth should receive a final restoration.
One-Appointment Technique. The value of re-entry and re-excavation has been questioned by some clinicians when viewed in light of numerous studies reporting success rates of indirect pulp capping with calcium hydroxide ranging from 73 to 98% After cavity preparation, if all carious dentin was removed except the portion that would expose the pulp, re-entry might be unnecessary. Conversely, if the clinician had to leave considerably more carious dentin owing to patient symptoms, re-entry would be advised to confirm reparative dentin and pulp exposure status. If a pulp exposure occurs during re-entry, a more invasive vital pulp therapy technique such as direct pulp capping or pulpotomy would be indicated.
Photomicrograph of four layers of healing under indirect pulp capping of a permanent molar ofa 141⁄2-year-old child. Zinc oxide–eugenol cement capping after excavation of the necroticdentin layer only. No pain 480 days later when extracted. 1= carious decalcified dentin; 2 =rhythmic layers of irregular irritational dentin; 3 = regular tubular dentin; 4 = normal pulpwith slight increase in fibrous elements. Held-Wydler E.
King and associates, Aponte et al. and Parikh et al., determined that the residual layer of carious dentin, left in the indirect pulp-capping technique, can be sterilized with either ZOE cement or calcium hydroxide. It cannot be presumed that all of the remaining infected or affected dentin becomes remineralized. In contrast to ZOE, residual dentin will increase in mineral content when in contact with calcium hydroxide. A minimum indirect pulp post-treatment time period of 6 to 8 weeks should be allowed to produce adequate remineralisation of the cavity floor. This desirable outcome is essentially dependent on the maintenance of a patent seal against micro leakage by the temporary and final restorations. In this regard, the newer resin-reinforced glass ionomer cements and dentin bonding agents should be considered.
Direct pulp capping involves the placement of a biocompatible agent on healthy pulp tissue that has been inadvertently exposed from caries excavation or traumatic injury. The treatment objective is to seal the pulp against bacterial leakage, encourage the pulp to wall off the exposure site by initiating a dentin bridge, and maintain the vitality of the underlying pulp
Indications : Small mechanical or traumatic exposures in primary or permanent teeth; optimal chance for favourable response The classic indication for direct pulp capping has been for “pinpoint” mechanical exposures that are surrounded with sound dentin Frigoletto noted that small exposures and a good blood supply have the best healing potential. An empirical guideline has been to limit the technique to exposure diameters of less than 1 mm.Contraindications : A history of spontaneous and nocturnal toothaches, excessive tooth mobility, thickening of the periodontal ligament, radiographic evidence of furcal or periradicular degeneration, uncontrollable hemorrhage at the time of exposure, and purulent or serous exudatefrom the exposure.
Steps in the procedure1. Débridement. Kalins and Frisbee have shown that necrotic and infected dentin chips are invariably pushed into the exposed pulp during the last stages of caries removal. This debris can impede healing in the area by causing further pulpal inflammation and encapsulation of the dentin chips. Therefore, it is prudent to remove peripheral masses of carious dentin before beginning the excavation where an exposure may occur. When an exposure occurs, the area should be appropriately irrigated with non-irritating solutions such as normal saline to keep the pulp moist
2. Hemorrhage and Clotting Hemorrhage at the exposure site can be controlled with cotton pellet pressure. A blood clot must not be allowed to form after the cessation of hemorrhage from the exposure site as it will impede pulpal healing. The capping material must directly contact pulp tissue to exert a reparative dentin bridge response. Hemolysis of erythrocytes results in an excess of hemosiderin and inflammatory cellular infiltrate, which prolongs pulpal healing.
3. Exposure Enlargement There have been recommendations that the exposure site be enlarged by a modification of the direct capping technique known as pulp curettage or partial pulpotomy prior to the placement of the capping material. Enlarging this opening into the pulp itself serves three purposes:1. it removes inflamed and/or infected tissue in the exposed area;2. it facilitates removal of carious and noncarious debris, particularly dentin chips; and3. it ensures intimate contact of the capping medicament with healthy pulp tissue below the exposure site.
4. Bacterial Seal Watts and Paterson and Cox have emphasized the fact that bacterial microleakage under various restorations causes pulpal damage in deep lesions, not the toxic properties of the cavity liners and/or restorative materials. The success of pulp-capping procedures is dependent on prevention of microleakage by an adequate seal. Cox et al. have shown that pulp healing is more dependent on the capacity of the capping material to prevent bacterial microleakage rather than the specific properties of the material itself.
Medications and Materials Many medicaments and materials have been suggested to cover pulp exposures and initiate tissue healing and/or hard structure repair. Calcium hydroxide, in one form or another, has been singled out by a myriad of authors as the medicament of choice for pulp exposures. Antibiotics, calcitonin, collagen, corticosteroids, cyanoacrylate, formocresol, and resorbable tricalcium phosphate ceramic have also been investigated, with varying degrees of success. These compounds, with the exception of formocresol, have not had sufficient clinical impact to be adopted as the material of choice in direct pulp capping, especially in the pediatric age groups.
A B C D Effect of calcium hydroxide and time on the healing of the capped pulp. A, Twenty-fourhours after application of calcium hydroxide. B, After 2 or 3 weeks. C, After 4 or 5 weeks. D, After 8 weeks. Vermeersch AG
Outcome The salient features of a clinically successful direct pulp capping treatment (with or without bridging) are maintenance of pulp vitality, absence of sensitivity or pain, minimal pulp inflammatory responses, and absence of radiographic signs of dystrophic changes. It is generally considered that pulps inadvertently exposed and asymptomatic in the preoperative period are more apt to survive when capped. The prognosis is far less favorable if an attempt is made to cap an inflamed pulp infected from caries or trauma. Also, the wide-open apices and high vascularity of young permanent teeth enhance the successful outcome of direct capping techniques
A pulpotomy is defined as the surgical removal of the entire coronal pulp presumed to be partially or totally inflamed and quite possibly infected, leaving intact the vital radicular pulp within the canals. A germicidal medicament is then placed over the remaining vital radicular pulp stumps at their point of communication with the floor of the coronal pulp chamber. This procedure is done to promote healing and retention of the vital radicular pulp. The treatment objective is to maximize the opportunity for apical development and closure, known as apexogenesis, and enhance continual root dentin formation. Dentin bridging may occur as a treatment outcome of this procedure depending on the type of medicament used Additional variables thought to influence treatment outcome include the medication type, concentration, and time of tissue contact.
Indications Pulpotomy candidates should demonstrate1. clinical and radiographic signs of radicular pulp vitality, absence of pathologic change,2. restorability, and3. at least two-thirds remaining root length. Pulpotomised teeth should receive stainless steel crowns as final restorations to avoid potential coronal fracture at the cervical region. Pulpotomy is recommended for young permanent teeth with incompletely formed apices and cariously exposed pulps that give evidence of extensive coronal tissue inflammation.
Contraindications Teeth with a history of spontaneous pain should not be considered. If profuse hemorrhage occurs on entering the pulp chamber, the one-step pulpotomy is also contraindicated.Other contraindications are pathologic root resorption, roots that are two-thirds resorbed or internal root resorption, interradicular bone loss, presence of a fistula, or presence of pus in the chamber
Calcium hydroxide - alkaline, produces superficial necrosis of the pulp stimulates development of calcified barrier Formocresol – formaldehyde/cresol in glycerin-Acts by fixation of remaining pulp tissue Ferric Sulphate may be the material of choice in future - Agglutinates blood protein without clot formation - Equal results as with dilute formocresol with less toxicity Glutaraldehyde- was found to be less cytotoxic “when used as a pulpotomy agent.” MTA- acts as cell inductive agent BMP, Calcium phosphate cements Non-pharmaco-therapeutic techniques- Electrosurgery and lasers
Steps for Single appt. technique Anesthetize the tooth and tissue. Isolate the tooth to be treated with a rubber dam. Excavate all caries. Remove the dentin roof of the pulp chamber with a high-speed fissure bur Remove all coronal pulp tissue with a slow-speed No. 6 or 8 round bur Sharp spoon excavators can remove residual tissue remnants. Achieve hemostasis with dry cotton pellets under pressure. Apply diluted formocresol to the pulp on a cotton pellet for 3 to 5 minutes. Place a ZOE cement base without incorporation of formocresol Restore the tooth with a stainless steel crown
Step-by-step technique inone-appointmentformocresol pulpotomy.A, Exposure of pulp byroof removal.B, Coronal pulpamputation with a roundbur. Hemostasis with drycotton or epinephrine.C, Application offormocresol for 1 minute.Excess medicamentis expressed from cottonbefore placement. D, Following formocresolremoval, zinc oxide–eugenol base andstainless steel crown areplaced. Ingle
Two-Appointment Pulpotomy.Indications.The two-appointment technique is indicated if there is evidence of sluggish or profuse bleeding at the amputation site, difficult-to-control bleeding, Slight purulence in the chamber but none at the amputation site, thickening of the periodontal ligament, or a history of spontaneous pain without other contraindications.Procedure. A cotton pellet moistened with diluted formocresol is sealed into the chamber for 5 to 7 days with a durable temporary cement. At the second visit, the temporary filling and cotton pellet are removed and the chamber is irrigated with hydrogen peroxide. A ZOE cement base is placed. The tooth is restored with a stainless steel crown. Verco and Allen found no difference in the success rate between one- stage and two-stage procedures.
Outcome The formocresol treatment might be effective because the open apical foramen of immature permanent teeth would be conducive to an in-growth of connective tissue at the apex in the form of proliferating fibroblasts. Because linear osteodentin calcification may develop as a response to formocresol pulpotomies over time, there has been considerable concern expressed by endodontists of the difficulty in renegotiating treated young permanent canals after the apices have closed.
Because of improved clinical outcomes, calcium hydroxide is the recommended pulpotomy agent for carious and traumatic exposures in young permanent teeth, particularly with incomplete apical closure . Following the closure of the apex, it is generally recommended that conventional root canal obturation be accomplished to avoid the potential long-term outcome of root canal calcification. The rationale was introduced by Teuscher and Zander in 1938, who described it as a “vital” technique. Their histologic studies showed that the pulp tissue adjacent to the calcium hydroxide was first necrotized by the high pH (11 to 12) of the calcium hydroxide.
This necrosis was accompanied by acute inflammatory changes in the underlying tissue. After 4 weeks, a new odontoblastic layer and, eventually, a bridge of dentin developed. Later investigations showed three identifiable histologic zones under the calcium hydroxide in 4 to 9 days: (1) coagulation necrosis, (2) deep- staining basophilic areas with varied osteodentin, and (3) relatively normal pulp tissue, slightly hyperemic, underlying an odontoblastic layer. As with direct pulp capping, the presence of a dentinal bridge is not the sole criterion of success. The bridge may be incomplete and may appear histologically as doughnut, dome, or funnel shaped or filled with tissue inclusions. It is also possible for the remaining pulp to be walled off by fibrous tissue with no dentin bridge evident radiographically.
Procedure. Anesthetize the tooth to be treated and isolate under a rubber dam. Excavate all caries and establish a cavity outline. Irrigate the cavity with water and lightly dry with cotton pellets. Remove the roof of the pulp chamber with a high-speed fissure bur. Amputate the coronal pulp with a large low-speed round bur or a high-speed diamond stone with a light touch.(Granath et al) Control hemorrhage with a cotton pellet applied with pressure or a damp pellet of hydrogen peroxide.
Place a calcium hydroxide mixture over the radicular pulp stumps at the canal orifices and dry with a cotton pellet. Place quick-setting ZOE cement or resin-reinforced glass ionomer cement over the calcium hydroxide to seal and fill the chamber. If the crown is severely weakened by decay, a stainless steel crown rather than an amalgam restoration should be used to prevent cusp fractures The patient should be re-evaluated every three months for the first year, and then every 6 months for 2 to 4 years to determine if successful root formation is taking place and that there are no signs of pulp necrosis, root resorption or periradicular pathosis.
Calcium hydroxide pulpotomy, youngpermanent molar.A, Pulp of a first permanent molar exposed bycaries (white arrow).B, Calcified dentin bridges (arrows) over vitalpulp in canals. Note open apices.C, Pulp recession (arrows) and continued rootdevelopment indicative of continuing pulpvitality.McDonald RE. Dentistry for the child andadolescent. 2nd ed.
Apexogenesis is a histological term that has been used to describe the result of vital pulp procedures that allow the continued physiologic development and formation of the root’s apex. Formation of the apex in vital, young, permanent teeth can be accomplished by implementing the appropriate vital pulp therapy (ie, indirect pulp treatment, direct pulp capping, partial pulpotomy for carious exposures and traumatic exposures). The goal of apexogenesis is the preservation of vital pulp tissue so that continued root development with apical closure may occur.
The partial pulpotomy for carious exposures is a procedure in which the inflamed pulp tissue beneath an exposure is removed to a depth of 1 to 3 mm or, in some cases, deeper to reach healthy pulp tissue. Pulpal bleeding must be controlled, and the site should be covered with calcium hydroxide or MTA. A restoration that seals the tooth from microleakage is placed. A partial pulpotomy is indicated in a young permanent tooth for a small (<2 mm) carious pulp exposure in which the pulpal bleeding is controlled in 1 to 2 minutes. The tooth must be vital, with a diagnosis of normal pulp or reversible pulpitis. The remaining pulp should continue to be vital after partial pulpotomy. There should be no adverse clinical signs or symptoms such as sensitivity, pain, or swelling. There should be no radiographic sign of internal or external resorption, abnormal canal calcification, or periapical radiolucency postoperatively. Teeth having immature roots should continue normal root development and apexogenesis.
The partial pulpotomy for traumatic exposures is a procedure in which the inflamed pulp tissue beneath an exposure is removed to a depth of 1 to 3 mm to reach the deeper healthy tissue. Pulpal bleeding is controlled, and the site then is covered with calcium hydroxide or MTA. A restoration that seals the tooth from microleakage is placed. This pulpotomy is indicated for a vital, traumatically-exposed, young permanent tooth, especially one with an incompletely formed apex. Pulpal bleeding after removal of inflamed pulpal tissue must be controlled. Neither the time between accident and treatment nor size of exposure is critical if the inflamed superficial pulp tissue is amputated. The remaining pulp should continue to be vital after partial pulpotomy. There should be no adverse clinical signs or symptoms of sensitivity, pain, or swelling. There should be no radiographic sign of internal or external resorption, abnormal canal calcification, or periapical radiolucency postoperatively. Teeth having immature roots should show continued normal root development and apexogenesis.
Apexification is a method of inducing root end closure of an incompletely formed nonvital permanent tooth by removing the coronal and nonvital radicular tissue just short of the root end and placing in the canal a suitable biocompatible agent such as calcium hydroxide (several treatments with a fresh agent may be necessary) or MTA. This procedure is indicated for nonvital permanent teeth with incompletely formed roots. The procedure should induce root end closure (apexification) at the apices of immature roots or an apical barrier, as evidenced by radiographic evaluation. Adverse post treatment clinical signs or symptoms of sensitivity, pain, or swelling should not be evident. There should be no radiographic evidence of external root resorption, lateral root pathosis, or breakdown of periradicular supporting tissues during or following therapy.
In the apexification technique the canal is cleansed and sanitized in the routine endodontic manner with the use of a rubber dam. The access opening is made,the length of the canal is established radiographically and the canal is cleansed as thoroughly as possible. Frequent irrigation with sodium hypochlorite helps remove debris from the canal. After thorough debridement the canal is dried and just barely medicated with CMCP or some other suitable intracanal medicament. It is then sealed with a temporary cement. When the tooth is free of signs and symptoms of infection, the canal is dried and filled with a stiff mix of Ca(OH)2 and CMCP.
After the canal is filled, the access opening must be sealed with a permanent filling material. If the outer seal is defective, the calcium hydroxide paste is lost and recontamination of the canal will result Composite resin or silicate cement is recommended for anterior teeth and amalgam for posterior teeth. The usual time required to achieve apexification is 6 to 24 months (average 1 year +/- 7 months). Factors that lead to increased time are the presence of a radiolucent lesion, inter-appointment symptoms, and loss of the external seal with re-infection of the canal. During this time the patient is recalled at 3- month intervals for monitoring of the tooth.
If any signs or symptoms of re-infection or pathology occur during this phase of treatment, the canal is recleaned and refilled with the Ca(OH)2 paste. The patient is recalled until radiographic evidence of apexification has become apparent. Then the tooth is re-entered and clinical verification of apexification is made by the failure of a small instrument to penetrate through the apex after removal of the Ca(OH)2 paste. If apexification is incomplete, the canal is repacked with Ca(OH)2 paste, and the periodic recall continues.Source: Cohen S, Burns R: Pathways of the Pulp, 6th edition.
Closure of root apex in a non vital carious molar using long term calcium hydroxidetreatment.
Pulpectomy in permanent teeth is conventional root canal (endodontic) treatment for exposed, infected, and/or necrotic teeth to eliminate pulpal and periradicular infection. In all cases, the entire roof of the pulp chamber is removed to gain proper access to the canals and eliminate all coronal pulp tissue. Following debridement and shaping of the root canal system, obturation of the entire root canal is accomplished with a biologically acceptable, nonresorbable filling material. Obturation as close as possible to the cementodentinal junction should be accomplished with gutta percha or other filling material acceptable.
Pulpectomy or conventional root canal treatment is indicated for a restorable permanent tooth with irreversible pulpitis or a necrotic pulp in which the root is formed fully. There should be evidence of a successful filling without gross overextension or underfilling in the presence of a patent canal. There should be no adverse post-treatment signs or symptoms such as prolonged sensitivity, pain, or swelling, and there should be evidence of resolution of pretreatment pathology with no further breakdown of periradicular supporting tissues clinically or radiographically.
Revascularization of a necrotic pulp has been considered possible only after avulsion of an immature permanent tooth. Skoglund et al. showed that pulp revascularization was possible in dog teeth and it took approximately 45 days The young tooth has an open apex and a short root that allows new tissue to grow into the pulp space relatively quickly. The pulp is necrotic but usually not degenerated and infected so that it can act as a scaffold into which the new tissue can grow.
Revascularization of the pulp space in a tooth with necrotic infected pulp tissue and apical periodontitis has been thought to be impossible until recently. Nygaard-Østby and Hjortdal successfully regenerated pulps after vital pulp removal in immature teeth but were unsuccessful when the pulp space was infected. However, if it were possible to create a similar environment as the avulsed tooth , revascularization should occur. Thus, if the canal is effectively disinfected, a scaffold into which new tissue can grow is provided and the coronal access effectively sealed, revascularization should occur similarly to that in an avulsed immature tooth.
A recent scientific finding, which may explain in part why apexogenesis can occur in these infected immature permanent teeth, is the discovery and isolation of a new population of mesenchymal stem cells (MSCs) residing in the apical papilla of incompletely developed teeth. These cells are termed stem cells from the apical papilla (SCAP), and they differentiate into odontoblast-like cells forming dentin Apical papilla is apical to the epithelial diaphragm, and there is an apical cell-rich zone lying between the apical papilla and the pulp. Importantly, there are stem/progenitor cells located in both dental pulp and the apical papilla, but they have somewhat different characteristics . Because of the apical location of the apical papilla, this tissue may be benefited by its collateral circulation, which enables it to survive during the process of pulp necrosis
Apical papilla. (A) An extracted human third molar depicting three immature roots with two piecesof apical papilla being removed from their apices (arrowheads) and one piece of apical papilla being peeled away from the root end but not completelydetached (arrow). (B) A developing root tip with attached apical papillawas cultured in vitro for 3 days before being processed for hematoxylin and eosin (H&E)staining. Odontoblasts (black arrows), apical cell-rich zone (openarrowheads), and apical papilla tissue are indicated. (C) Magnified view of the area indicated bythe yellow rectangle. JOE—Volume 34, Number 6, June 2008
Several case reports have documented revascularization of necrotic root canal systems by disinfection followed by establishing bleeding into the canal system via over instrumentation. An important aspect of these cases is the use of intracanal irrigants (NaOCl and chlorhexidine) with placement of antibiotics (e.g. a mixture of ciprofloxacin, metronidazole, and minocycline paste) for several weeks. This particular combination of antibiotics effectively disinfects root canal systems and increases revascularization of avulsed and necrotic teeth, suggesting that this is a critical step in revascularization. The selection of various irrigants and medicaments is worthy of additional research.
(A) Radiographic image showing an incompletely developed apex and a periradicular radiolucency of tooth #29. Note the sinus tract that traces to the apex of tooth #29. (B) Radiographic view presenting a gutta-percha cone tracing to tooth #29, and a periradicular radiolucency associated with tooth #28. (C) Radiograph from 60-day follow-up visit after both teeth were medicated with triantibiotic paste. The sinus tract is still traced to the apex of tooth #29.(D)The radiograph demonstrating complete resolution of theradiolucency and continued developmentof the apex of both teeth at 6-month follow-up. (E) Follow-upat 5 years. JOE — Volume 34, Number 7, July 2008
Although these case reports are largely from teeth with incomplete apical closures, it has been noted that reimplantation of avulsed teeth with an apical opening of approximately 1.1 mm demonstrate a greater likelihood of revascularization. This finding suggests that revascularization of necrotic pulps with fully formed (closed) apices might require instrumentation of the tooth apex to approximately 1 to 2mm in apical diameter to allow systemic bleeding into root canal systems. The revascularization method assumes that the root canal space has been disinfected and that the formation of a blood clot yields a matrix (e.g., fibrin) that traps cells capable of initiating new tissue formation.
(A) Radiographic image showing anincompletely developed apex and aperiradicular radiolucency of tooth#29. Note the sinus tract that tracesto the apexof tooth #29.(B) Photograph of a purulenthemorrhagic exudate dischargedfrom tooth #29.(C) Radiograph presenting theplacement of MTA. (D) 3-month recallradiograph. A slight increase of thethickness of the root canal wall andcontinued development of the apexare observed.(E)Two-year radiograph showingcontinuedroot development.Case Report/Clinical TechniquesJOE
Advantages First, this approach is technically simple and can be completed using currently available instruments and medicaments without expensive biotechnology. Second, the regeneration of tissue in root canal systems by a patient’s own blood cells avoids the possibility of immune rejection and pathogen transmission from replacing the pulp with a tissue engineered construct.Caution The case reports of a blood clot having the capacity to regenerate pulp tissue are exciting, but caution is required, because the source of the regenerated tissue has not been identified. Animal studies and more clinical studies are required to investigate the potential of this technique before it can be recommended for general use in patients.
One of the clinical treatment options for missing teeth is autotransplantation. The process often involves extraction of a supernumerary tooth or third molar and implantation into a recipient site. With regard to the status of pulp survival and root formation of the transplanted immature teeth, the clinical observations shown by Tsukiboshi have been that• in young teeth with some root formation, it will continue to develop to some extent or to completion after transplantation; and• pulp tissue will be eventually replaced by hard tissue. Both SCAP and HERS appear to be important for the continued root development after transplantation.
Based on research in young avulsed teeth and on a recent study on infected teeth, it is more likely that the newly formed tissue in the pulp space is more similar to periodontal ligament than the pulp tissue. It appears that there is about a 30% chance of pulp tissue re- entering the pulp space. Future research will need to be done in order to stimulate pulp regeneration from the pluri-potential cells in the periapical region. It may also be a good idea to partially resect the pulp in an irreversible pulpitis case, and with the help of a synthetic scaffold it may be possible to re-grow the pulp rather than remove the entire pulp and replace it with a synthetic filling material.
Endodontics – Fifth Edition - John I. Ingle, Leif K. Bakland Dentistry for the adolescent- Castaldi and Brass Paediatric Dentistry- Pinkham Clinical Pedodontics -Finn Dentistry for Child and Adolescent- Mc Donald Pathways of the Pulp, 6th edition- Cohen S, Burns R Endodontic Practice- Grossman Text Book Of Pedodontics - Shobha Tandon Martin Trope. Treatment of Immature Teeth; Endodontic Topics 2006 Jung et al. Biologically Based Treatment of Immature Permanent Teeth with Pulpal Necrosis; JOE—Volume 34, Number 7, July 2008 Huang et al. The Hidden Treasure in Apical Papilla; JOE — Volume 34, Number 6, June 2008