Introduction
The pulp Therapy has many controvercy than any other treatment in pediatric dentistry specially pulpotomy.This review article presented in the context of rationals that have guided development of new and very divergent treatment modalities while no reviews presented a framework for the systemic analysis of past development or future trends.1
According to the AAPD a pulpotomy is performed in a primary tooth with extensive caries but without evidence of radicular pathology when caries removal results in a carious or mechanical pulp exposure. The coronal pulp is amputated and the remaining vital radicular pulp tissue is treated with a long term clinically successful medicament such as Buckley’s solution of formocresol or ferric sulphate.2
According to Finn (1995), pulpotomy is defined as the complete removal of coronal portion of the dental pulp, followed by the placement of the suitable dressing or medicament that will promote healing and preserve the vitality of the tooth.
Indications of pulpotomy
Pulp exposure during removal of caries in primary teeth
Pulp exposure due to trauma
No history of spontaneous pain
Hemorrhage from exposure site is easily controllable
Hemorrhage from the exposure site is bright red in colour
No intraradicular bone loss
No intraradicular radioleucency
Absence of abscess or fistula
In young permanent tooth with vital exposed pulp and incompletely formed root
History of spontaneous pain
Pulpotomy can be performed using different techniques including non pharmacotherapeutic treatments such as electrosurgey and lasers or pharmacotherapeutic approaches by dressing pulp tissue with different medicaments or biological materials such as formocresol, glutaraldehyde, ferric sulphate, freezed dried bone, bone morphogenic protein (BMP), osteogenic protein, sodium hyochloride, calcium enriched mixture (CEM), enriched collagen solutions and fully synthetic nano crystalline hydroxyappatite paste.
Classification of pulpotomy
Pulpotomy can be classified according to treatment objectives (Don M Ranly 1994).1
Table 1
Formocresol Pulpotomy/ Single Visit Pulpotomy
Pulpotomy using formocresol was first introduced by Buckley in 19043
Buckley’s formula consisted of
The Ph of Buckley’s solution is 5.1
Currently 1:5 dilution of Buckley’s Formocresol is commonly used. A diluent consisting of 3 part of glycerine (90 ml) added to 1 part distilled water (30ml) is prepared. Later 4 parts of diluent (120 ml) is mixed with 1 part of buckley’s formocresol (30 ml).
Sweet (1930) proposed the multivisit technique.
Doyle (1962) proposed the two visit pulpotomy.
Spedding (1965) gave a five minute protocol (partial devitalization).
Redig gave five minutes single visit pulpotomy
Garcia Godoy (1991) advocated 1 min. single visit pulpotomy.
Current pulpotomy procedure uses 4 minutes of application time.
Steps of single visit pulpotomy
Anaesthesize the tooth and tissue
Isolate the tooth with rubber dam
Remove caries with a high speed straight bur without entering the pulp chamber
Remove the roof of pulp chamber with a slow speed round bur
Remove coronal pulp with a large excavator or a large round bur
Apply formocresol with a pledget of cotton and apply it on the amputated pulp for 4 minutes.
Remove formocresol pledget after 4 minutes and check that hemorrhage stopped
Filled the pulp chamber with Zinc Oxide Eugenol cement
Restore the tooth with stainless crown.
Mechanism of action of formocresol
Formocresol prevents tissue autolysis by binding the peptide group of side chain of amino acid. It is a reversible process without changing of basic structure of protein molecules.
Controversy between 1 minute formocresol pulpotomy vs 5 minutes formocresol pulpotomy
Zohra et al (2011) used 1 minute formocresol pulpotomy and reported success rates comparable to techniques that used the 5 minute diluted or full strength solutions reported in the literature.
Histological changes
Massler and Mansukhani (1959) reported that between 7 to 14 days three zones appeared.
A broad acidophllic zone (fixation
A broad pale – staining zone (atrophy
A broad zone of inflammatory cells
After 60 days only strand of eosinophillic fibrous tissue remained at the exposure site.
Concerns of formocresol
Formocresol is believed to cause mutagenecity, cytogenecity and carcinogenicity.
IARC (June 2004) classified formaldehyde as a carcinogen that has potency to cause leaukemia and nasopharyngeal carcinoma. However Ranly calculated the formocresol concentration following pulpotomy and reported that 3000 pulpotomies have to be performed in the same individual to reach toxic level.
Systemic distribution – Myers (1978) while using radioisotope labelled formaldehyde to perform pulpotomies in animals found its presence in PDL, dentine, bone and urine.
Antigenocity – Thoden Valzen found immunogenic potential of formaldehyde in rabbits, dogs, and guinea pigs.
Mutagenecity and cytogenecity – According to studies done formaldehyde dentaures nuclic acids by forming methylol derivaties that renders genetic machinery inoperable. It may also affect biosynthesis and cell reproduction by interacting with DNA and RNA.
Contraindications
It is a two stage procedure involving the use of paraformaldehyde. The medicament has a devitalizing, mummifying and bactericidal action.
Materials used in two visit pulpotomy
Gysi triopaste consit of tricresol, cresol, glyserine, paraformaldehyde, zinc oxide eugenol
Easlick’s paraformaldehyde paste consist of paraformaldehyde, procaine base, powdered asbestos, petroleum jelly
Paraform devitalizing paste consist of paraformaldehyde, lignocaine, propylene glycol, carbowax, carmine for colour.
Glutaraldehyde Pulpotomy
Glutaraldehyde for pulp fixation was proposed by Gravenmade (1975), In recent years glutaraldehyde has been proposed as an alternative to formocresol based on its superior fixative properties, self limiting penetration, low antigenecity, low toxicity and elimination of cresol. Glutaraldehyde has a cross liniking property superior to that of formocresol.3
Histology
Narrow zone of eosinophillic stained and compressed fix tissue isi found beneath the area of application which blends with underlying normal pulp.
Concentration and application time of glutaraldehyde
Garcia Godoy (1987) found that increase in concentration and longer time improves fixation and suggested the use of 4% glutaraldehyde for 4 minutes or 8% glutaraldehyde for 2 minutes.
Ferric Sulphate Pulptomy
It is a non aldehyde chemical which is used as a pulpotomy material. Ferric sulphate is a coagulative and hemostatic agent this compound was proposed as a pulpotomy agent that it prevents the problem in clot formation thereby minimizing chances of inflammation and internal resorption.4
Calcium Hydroxide Pulpotomy
Calcium hydroxide was introduced to dentistry in 1938 by Nygren. In 1930 Herman showed that calcium hydroxide stimulated the formation of new dentine when placed in contact with human pulp tissue. 5
Calcium hydroxide was used as a medicament for indirect pulp capping, direct pulp capping and pulpotomy in permanent and primary teeth because of its bactericidal effect and ability to form reparative dentine bridge however, there are a controversies regarding the us e of calcium hydroxide in primary teeth pulpotomy, because it results in the development of chronic pulpal inflammation and internal resorption.
In case of deciduous teeth even before the actual time for exfoliation there is an inherent predelliction for the formation of odontoclasts. The preexisting propencity for transformation could be influenced and hastened by placement of calcium hydroxide, probly through its high alkaline ph. It is very likely that high alkaline ph of calcium hydroxide could trigger existing pre- odontoclasts (stromal undifferentiated mesenchymal cells) to transform into odontoclasts which causes internal resorption. Hence, calcium hydroxide is not recommended as a pulpotomy agent in case of primary teeth.
Newer Concepts in Pulpotomy
MTA pulpotomy
As a member of hydroxycilic calcium silicate cement MTA was introduced by Lee et al and patented by Torabinejad and White in 1995.6
MTA consist of tricalcium silicate, bismuth oxide, tetracalcium alumina, ferrite, calcium sulphate dehydrate.
Mechanism of action
When MTA is mixed with water a colloidal gel with a ph 12.5 similar to that of calcium hydroxide is formed. MTA in contact with pulp tissue promotes dentin bridge formation.
Calcium Enriched Mixture Cement (CEM)
CEM cement was introduced as a endodontic filling material. The major componenets of the cement are calcium oxide, sulphur trioxide, phosphorus peroxide and silver dioxide.7
Electrosurgery
It is a non – pharmacological hemostatic technique which has been suggested for the pulpotomy procedure.8
Laser Pulpotomy
Lasers have been introduced to medicine and dentistry since the early 1960s. Different lasers are used in pediatric dentistry. These lasers include diagnosis of caries development (diode 655 mm), argon lasers for composite curing, Co2 lasers with wavelength of 10600 nm for soft tissue surgeries, Nd: YAG lasers with wavelength of 1064 nm as well as diode laser with wavelength of 810-980 nm for soft tissue cutting, the Erbium laser family including Er: YAG (2940 nm) and Er; Cr: YSGG (2780 nm) which were used in hard tissues, cavity preparation and in soft tissue surgery and also low power lasers which are used in stimulatory and inhibitory biologic process. Several studies have revealed that laser have proper effects in pulpotomy of primary teeth with results similar or even better than formocresol pulpotomy. The advantages of laser compared to conventional pulpotomy, are hemostasis, preservation of vital tissues near the tooth apex, absence of vibration and odor.9
Hz, Co2 laser and 632/980 nm diode lasers can be used for pulpotomy of primary teeth. Liu et al. in a clinical study compared the effects of Nd: YAG laser pulpotomy with FC on human primary teeth. They concluded that the success rates of the Nd: YAG laser was significantly higher than the FC pulpotomy.
Naocl Pulpotomy
Sodium hypochlorite has been used as an irrigant in dentistry for decades. Hafez and others demonstrated that the application of sodium hypochlorite selectively dissolves the superficiall necrotic pulp tissue while leaving the deeper healthy pulp tissue unharmed.10
BMP (Bone Morhogenic Protein)
BMP is thought to induce reparative dentin with recombinant dentinogenic proteins similar to the native proteins of the body. This was based on two classic observations.11
Huggins reported urinary tract epithelia implanted into the abdominal wall of dogs evoked bone formation
Urist also noted that demineralized bone matrix stimulated new bone formation when implanted in ectopic sites such as muscles. Urist concluded that bone matrix contains a factor capable of autoinduction and named it BMP.
The proteins most studied in pulp tissue have been BMP- 2, BMP-4 and BMP- 7 (OP-1).
Studies on BMP-7 has been done by Rutherford, Jepson and sin. Whereis studies on BMP 2 and 4 has been done by Nakashima and Ren.
Mechanism of action of BMP
Cells similar to fibroblasts migrate from the lower pulp tissue to the amputation zone (free from contamination) where they proliferate following this, there is formation of inactive matrix or utilization of the scaffolds itself, for the stem and undifferentiated mesenchymal cells to adhere tooth.
BMP – 2, 4 and 7 induce the differentiation of the adhered cells into odontoblasts that, inturn take part in the production and mineralization of the dentin matrix.
In a study done by Bengtsone et al (2008) they found the success rate of BMP-2 on human deciduous teeth to be 100%.
These suggests that rh BMP -2 is a material with inductive properties that should be further investigated for use as an alternative to pulpotomy treatment.
Enamel Matrix Derivative (EMD)
Enamel matrix derivative (emdogain) is an extract derived from porcine foetal tooth material and mainly consists of amelogenins, a class of protein known to induce the proliferation of periodontal ligamental cells.12
The ability of EMD to facilitate the regenerative process is well established. This process mimics normal odontogenesis and it is believed that reciprocates ectodermal signaling controls and patterns.
Currently emdogain gel (Straumann, Switzerland) has been successfully employed for pulpotomy procedures. EMD by means of amelogenin and ameline rich fraction has the potential to induce a process that seems to immitate normal dentinogenesis. It influences the odontoblsts and endothelial cells of the pulpal capillary vessels to create a calcified barrier over the pulp amputation site.
Mechanism of action of EMD
It has been reported that enamel matrix proteins participates in the differentiation and maturation of odontoblastic cells and when the pulp exposed to EMB, a substantial amount of reparative dentin like tissue is formed in a process much resembling classic wound healing which subsequent neogenesis of normal pulp tissue. These formation of new dentin starts from within the pulp at some distance from the exposure site.
Jumana and Ahmed reported the clinical success of 93% using emdogain for pulpectomy.
Propolis
Propolis is a wax cum resin substance that is produced by bees.13
It is shown to have antibacterial property
Antiviral property
Antifungal property
Hypotensive property
Cytostatic activity due to the presence of lavonoids (2 phenyl 1,4 – benzopyrine, aromatic acids and esters)
Histological studies has shown that the inflammatory response when propolis was applied to the amputated pulp was less severe, the area of pulp necrosis was smaller and there was more frequent formation of calcific barrier.
Ankaferd Blood Stopper (ABS)
It is a herbal extract obtained from 5 different plants 14
All of these plants has some effect on the endothelium, blood cells, angiogenesis cellular proliferation vascular dynamics and also as cell mediator.
Mechanism of action of ABS
Following application of ABS, it forms an encapsulated protein network that provides focal points for vital erythrocytes aggregation. ABS induce protein network formation with blood cells particularly erythrocytes covering the primary and secondary hemostatic system without disturbing individual coagulation factors.
It is suggested that ABS may be used to control pulpal hemorrhage following the mechanical exposure of the pulp. The levels of coagulation factors II, V, VIII, IX, X, XI and XII were not affected by ABS, therefore ABS can be used in patients with primary or /and secondary hemostasis including patients with disseminated intravascular coagulation.
Studies show the success rate of ABS in pulpotomy between the range of 89 -100%.
Bioactive Glass (BAG)
Bioactive glass has been studied for more than 30 years as a bone substitute. They react with aquous solutions and produce a carbonated apatite layer. BAG is biocompatible and has osteogenic potential. Many researchers claim that it has odontogenic potential and can formed reparative dentin.15 Animal studies by Salako et al reported that BAG showed localized area of inflammation in the pulp and four week all samples showed comparatively better result where the inflammation was resolved and an odontogenic layer was evident.
Nanohydroxy Apatite (NHA)
Hydroxyapatite has already been used in bone grafts in orthopedic and in dental applications due to its structural similarity with bone and teeth. Despite each biocompatibility, one of the problems related to hydroxyapatite is the release of crystals or agglomeres that could impair cell activity and hinder the regeneration process. As natural bone has nanoscale features, it is believed that nanostructured hydroxyapatite could improve the properties of synthetic bone.16
Recently a fully synthetic nanocrystallanize hydroxyapatite (NHA) paste containing approximately 65% water and 35% apatite particle was introduced.
The advantages of this material are
Its close contact with surrounding tissue
Its rapid resorption capacities
High number of molecules on its surface
The biocompatibility of NHA combined with its structural similarity to teeth allows NHA to stimulate odontoblasts thus promoting the formation of dentine bridges.
Shayegan (2010) in his study found NHA to be biocompatible and observed that it provoked mild inflammatory reaction in pulp tissue after pulpotomy.
Platelet Rich Plasma (PRP)
It was first introduced by Marx in 1998 for reconstruction of mandibular defects. PRP gel is an autologous modification of fibrin glue obtained from autologus blood used to deliver growth factors in high concentrations. It is an autologous concentration of human platelets in a small volume of plasma. It mimics the coagulation cascade leading to formation of fibrin clot which consolidates an adheres to application site.17
It is biocompatible, biodegradable and promotes healing. PRP has been found to work in 3 ways
Increase in cell division
Inhibition of excess inflammation by decreasing early macrophase proliferation and
Degranulation of the granules in platelets, which contain the synthesized and prepackaged growth factors
Studies have reported could clinical success rates of pulpotomy using PRP
PULPOTEC
Pulpotec is a radio-opaque, non resorbable paste that is used in pulpotomy. Its powder consists of polyoxymethelene, iodoform and liquid consist of dexamethasone acetate, formaldehyde, phenol and guaiacol.18
Mechanism of action
The mode of action is by cycatrization of the pulp stump at the chamber – canal interface, while maijtaining the structure of the underlying pulp.
Histological studies have shown no signs of inflammation but there was a discontinuity in the odontoblastic layer lining along the dentin walls.
Nigella Sativa Oil (NS)
Nigella sativa oil is extracted from the seeds of black cumin. It is shown to have bronchodilator, immunogenic potentiating, hypotensive, analgesic, antibacterial and anti-inflammatory activity.
Omar OM et al. in his studies found that pulpotomy is done with NS showed mild to moderate vasodilation, continuous odontoblastic layer and a few samples showed scattered inflammatory cell infiltration. 19
CVEK’S Pulpotomy
It is also known as partial pulpootomy or calcium hydroxide pulpotomy. It was advocated by mejare and Cvek (1978). It is a form of vital pulp therapy performed in a immature permanent tooth with an open apex that consist of the surgical amputation of 2-3 mm of damaged and inflamed coronal pulp tissue. After removal of the damaged tissue, a dressing agent is placed to stimulate healing and maintain the vitality of the remaining pulp. It has a success rate of 95% in the treatment of complicated crown fractures and 91 – 93% in cariously exposed immature asymptomatic permanent teeth.20
Indication
In young permanent immature teeth where the pulp has been exposed due to trauma or caries and the remaining radicular pulp is deemed to be vital by clinical and radiographic criteria wherein the root formation is not complete.
Procedure of cvek pulpotomy
Tooth is anaesthesize and isolated
Caries is removed with a high speed 801 – 016 ML diamond round bur with copious irrigation
Amputation of 2- 3 ml of the damaged coronal pulp is executed
The cavity is rinsed with normal saline
Cotton pellet moistened with saline is used with moderate pressure to attained hemostasis
Calcium hydroxide is then apply to the exposed pulp ensuring no clot formation takes place
The cavity is then sealed with temporary restorative material
At the 1 month follow up, the tooth should be asymptomatic and show radiographic evidence of root development and maturation
Then permanent restoration with amalgam is done
Mortal Pulpotomy
It is also known as non vital pulpotomy. Ideally speaking pulpotomy is done in the vital tooth and pulpectomy is done in case of nonvital tooth. But in some cases it is not possible to do a pulpectomy because of nonnegotiable root canals and lack of cooperation of the patients. In such cases a mortal pulpotomy is done.21
Conclusion
For the maintenance of the dental arch lenth in children, mastication, speech and esthetics presentation of the deciduous teeth are necessary until their permanent successors erupt. Appropriate procedures such as indirect pulp capping, direct pulp capping and pulpotomy are often considered for maintaining the vitality of the deciduous teeth. The most common treatment in case of pulp exposure in symptom free primary molars is pulpotomy though deciduous molar pulpotomy has serve adverse effects like internal root resorption, this is mainly due to diagnostic errors during pulp testing and technical failure while performing the procedure. Newer materials that are available as pulpotomy agents have also made regeneration of pulp tissue possible thus the only thing required while performing pulpotomy procedure is accurate diagnosis of the pulpal status and proper technique.
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